RESUMO Introdução: A biópsia renal (BR) percutânea é fundamental para diagnóstico e manejo de diversas patologias renais. Dados nacionais sobre BR nativa em pacientes pediátricos são escassos. Nosso objetivo foi revisar características demográficas, clínicas e padrões histopatológicos em crianças submetidas a BR percutânea nativa ao longo de 24 anos. Métodos: Estudo observacional retrospectivo de pacientes submetidos a BR percutâneas nativas em unidade de nefrologia pediátrica entre 1998 e 2021, comparando três períodos: período 1 (1998–2005), período 2 (2006–2013), período 3 (2014–2021). Resultados: Constatamos que foram realizadas 228 BR, 78 (34,2%) no período 1, 91 (39,9%) no período 2, 59 (25,9%) no período 3. A idade mediana na BR foi 11 (7–14) anos. As principais indicações para BR foram síndrome nefrótica (SN) (42,9%), hematúria e/ou proteinúria não nefrótica (35,5%), lesão renal aguda (13,2%). Glomerulopatias primárias foram mais frequentes (67,1%), principalmente doença de lesão mínima (DLM) (25,4%), nefropatia por IgA (12,7%), glomerulonefrite mesangioproliferativa (GN) (8,8%). Das glomerulopatias secundárias, nefrite lúpica (NL) foi a mais prevalente (11,8%). No grupo 1, hematúria e/ou a proteinúria não nefrótica foram os principais motivos para BR, ao contrário da SN nos grupos 2 e 3 (p < 0,01). A NL apresentou tendência crescente (período 1–3: 2,6%–5,3%) e a glomeruloesclerose segmentar focal (GESF) apresentou leve tendência decrescente (período 1–3: 3,1%–1,8%), sem significância estatística. Conclusões: A principal indicação para BR foi SN, que aumentou ao longo do tempo, justificando o achado de DLM como principal diagnóstico histológico. A NL apresentou aumento na incidência ao longo do tempo, enquanto os casos de GESF não aumentaram. Introdução (BR renais escassos demográficas anos Métodos 199 2021 períodos 1998–2005, 19982005 1998–2005 , 2005 (1998–2005) 2006–2013, 20062013 2006–2013 2006 2013 (2006–2013) 2014–2021. 20142021 2014–2021 . 2014 (2014–2021) Resultados 22 7 34,2% 342 34 (34,2% 9 39,9% 399 39 (39,9% 5 25,9% 259 25 (25,9% 7–14 714 14 (7–14 (SN 42,9%, 429 42,9% 42 (42,9%) eou ou 35,5%, 355 35,5% 35 (35,5%) 13,2%. 132 13,2% 13 (13,2%) 67,1%, 671 67,1% 67 (67,1%) (DLM 25,4%, 254 25,4% 4 (25,4%) 12,7%, 127 12,7% 12 (12,7%) GN (GN 8,8%. 88 8,8% 8 (8,8%) secundárias (NL 11,8%. 118 11,8% (11,8%) p 0,01. 001 0,01 0 01 0,01) 1–3 2,6%–5,3% 2653 6 (GESF 3,1%–1,8%, 3118 3,1%–1,8% 3,1%–1,8%) estatística Conclusões tempo histológico aumentaram 19 202 1998200 1998–200 200 (1998–2005 2006201 2006–201 201 (2006–2013 2014202 2014–202 (2014–2021 34,2 (34,2 39,9 (39,9 25,9 (25,9 7–1 71 (7–1 42,9 (42,9% 35,5 (35,5% 13,2 (13,2% 67,1 (67,1% 25,4 (25,4% 12,7 (12,7% 8,8 (8,8% 11,8 (11,8% 00 0,0 1– 2,6%–5,3 265 311 3,1%–1,8 20 199820 1998–20 (1998–200 200620 2006–20 (2006–201 201420 2014–20 (2014–202 34, (34, 39, (39, 25, (25, 7– (7– 42, (42,9 35, (35,5 13, (13,2 67, (67,1 (25,4 12, (12,7 8, (8,8 11, (11,8 0, 2,6%–5, 26 31 3,1%–1, 19982 1998–2 (1998–20 20062 2006–2 (2006–20 20142 2014–2 (2014–20 (34 (39 (25 (7 (42, (35, (13, (67, (12, (8, (11, 2,6%–5 3,1%–1 1998– (1998–2 2006– (2006–2 2014– (2014–2 (3 (2 ( (42 (35 (13 (67 (12 (8 (11 2,6%– 3,1%– (1998– (2006– (2014– (4 (1 (6 2,6% 3,1% (1998 (2006 (2014 2,6 3,1 (199 (200 (201 3, (19 (20

Introduction: Percutaneous kidney biopsy (KB) is crucial to the diagnosis and management of several renal pathologies. National data on native KB in pediatric patients are scarce. We aimed to review the demographic and clinical characteristics and histopathological patterns in children who underwent native percutaneous KB over 24 years. Methods: Retrospective observational study of patients undergoing native percutaneous KB in a pediatric nephrology unit between 1998 and 2021, comparing 3 periods: period 1 (1998–2005), period 2 (2006–2013), and period 3 (2014–2021). Results: We found that 228 KB were performed, 78 (34.2%) in period 1, 91 (39.9%) in period 2, and 59 (25.9%) in period 3. The median age at KB was 11 (7–14) years. The main indications for KB were nephrotic syndrome (NS) (42.9%), hematuria and/or non-nephrotic proteinuria (35.5%), and acute kidney injury (13.2%). Primary glomerulopathies were more frequent (67.1%), particularly minimal change disease (MCD) (25.4%), IgA nephropathy (12.7%), and mesangioproliferative glomerulonephritis (GN) (8.8%). Of the secondary glomerulopathies, lupus nephritis (LN) was the most prevalent (11.8%). In group 1, hematuria and/or non-nephrotic proteinuria were the main reasons for KB, as opposed to NS in groups 2 and 3 (p < 0.01). LN showed an increasing trend (period 1–3: 2.6%–5.3%) and focal segmental glomerular sclerosis (FSGS) showed a slight decreasing trend (period 1–3: 3.1%–1.8%), without statistical significance. Conclusions: The main indication for KB was NS, which increased over time, justifying the finding of MCD as main histological diagnosis. LN showed an increase in incidence over time, while FSGS cases did not increase. Introduction (KB pathologies scarce years Methods 199 2021 periods 1998–2005, 19982005 1998–2005 , 2005 (1998–2005) 2006–2013, 20062013 2006–2013 2006 2013 (2006–2013) 2014–2021. 20142021 2014–2021 . 2014 (2014–2021) Results 22 performed 7 34.2% 342 34 (34.2% 9 39.9% 399 39 (39.9% 5 25.9% 259 25 (25.9% 7–14 714 14 (7–14 (NS 42.9%, 429 42.9% 42 (42.9%) andor or nonnephrotic non 35.5%, 355 35.5% 35 (35.5%) 13.2%. 132 13.2% 13 (13.2%) 67.1%, 671 67.1% 67 (67.1%) (MCD 25.4%, 254 25.4% 4 (25.4%) 12.7%, 127 12.7% 12 (12.7%) GN (GN 8.8%. 88 8.8% 8 (8.8%) (LN 11.8%. 118 11.8% (11.8%) p 0.01. 001 0.01 0 01 0.01) 1–3 2.6%–5.3% 2653 6 (FSGS 3.1%–1.8%, 3118 3.1%–1.8% 3.1%–1.8%) significance Conclusions time 19 202 1998200 1998–200 200 (1998–2005 2006201 2006–201 201 (2006–2013 2014202 2014–202 (2014–2021 34.2 (34.2 39.9 (39.9 25.9 (25.9 7–1 71 (7–1 42.9 (42.9% 35.5 (35.5% 13.2 (13.2% 67.1 (67.1% 25.4 (25.4% 12.7 (12.7% 8.8 (8.8% 11.8 (11.8% 00 0.0 1– 2.6%–5.3 265 311 3.1%–1.8 20 199820 1998–20 (1998–200 200620 2006–20 (2006–201 201420 2014–20 (2014–202 34. (34. 39. (39. 25. (25. 7– (7– 42. (42.9 35. (35.5 13. (13.2 67. (67.1 (25.4 12. (12.7 8. (8.8 11. (11.8 0. 2.6%–5. 26 31 3.1%–1. 19982 1998–2 (1998–20 20062 2006–2 (2006–20 20142 2014–2 (2014–20 (34 (39 (25 (7 (42. (35. (13. (67. (12. (8. (11. 2.6%–5 3.1%–1 1998– (1998–2 2006– (2006–2 2014– (2014–2 (3 (2 ( (42 (35 (13 (67 (12 (8 (11 2.6%– 3.1%– (1998– (2006– (2014– (4 (1 (6 2.6% 3.1% (1998 (2006 (2014 2.6 3.1 (199 (200 (201 2. (19 (20

ABSTRACT Introduction: Chronic Kidney Disease has gained interest due to its high morbidity and mortality rate. In addition to vascular causes and diabetes mellitus, an unknown cause has been identified in young farmers. Objective: This study aims to determine the prevalence of the population on hemodialysis, suspected of Chronic Interstitial Nephritis in agricultural communities, to categorize the true etiology of their renal pathology. Methodology: A descriptive observational design was applied during December 2022, January, and February 2023; and 684 patients of both sexes were surveyed in 8 hemodialysis centers in the Capital and the Central Department of Paraguay. Results: The prevalence of suspected cases due to the exposure to risk factors was 18.1%. This figure could be higher since 22.6% of patients with type 2 diabetes mellitus did not present clinical retinopathy or other clinical signs of the disease at the time of the diagnosis of kidney failure. This scenario warns us of a probable misdiagnosis in a considerable number of patients. Conclusion: The importance of this research lies in generating preventive actions in the agricultural population and raising awareness in the medical community about the diagnostic relevance of this pathology to improve the quality and prognosis of life in the Paraguayan population.

RESUMEN Introducción: La Enfermedad Renal Crónica ha cobrado interés debido a su alta tasa de morbimortalidad. Además de las causas vasculares y de la diabetes mellitus, se ha identificado una causa de Origen Desconocido en jóvenes agricultores. Objetivo: El objetivo del estudio es determinar la prevalencia de la población en hemodiálisis, sospechosa de la Nefritis Intersticial Crónica en Comunidades Agrícolas, para categorizar la verdadera etiología de su patología renal. Metodología: Se aplicó un diseño observacional descriptivo durante los meses de diciembre de 2022, enero y febrero de 2023; y se encuestó a 684 pacientes de ambos sexos en 8 centros de hemodiálisis de la Capital y el Departamento Central del Paraguay. Resultados: La prevalencia de casos sospechosos por la exposición a factores de riesgo resultó ser del 18.1%. Esta cifra podría ser mayor, ya que 22.6% de los pacientes con diabetes mellitus tipo 2, no presentó retinopatía clínica ni otros signos clínicos de la enfermedad al momento del diagnóstico de la falla renal. Este panorama nos advierte de un probable diagnóstico desacertado en una cantidad considerable de pacientes. Conclusión: La importancia de esta investigación se sustenta en generar acciones preventivas en la población agrícola y concientizar a la sociedad médica de la relevancia diagnóstica de esta patología para mejorar la calidad y pronóstico de vida en la población paraguaya.

Resumen Introducción: Las porfirias son trastornos enzimáticos de la síntesis del hemo. Las porfirias hepáticas agudas (PHA) se presentan con síntomas neuroviscerales agudos, como dolor abdominal, náuseas, vómitos, estreñimiento, debilidad muscular, neuropatía, taquicardia e hipertensión. La deficiencia de ácido 5-aminolevulínico deshidratasa (ALAD) es un trastorno autosómico recesivo raro que provoca poca o ninguna elevación de porfobilinógeno, pero eleva el ácido 5-aminolevulínico y la coproporfirina III urinaria. No hay registros de este tipo de porfiria en Colombia. En la fase aguda requiere manejo integral, desde hemoterapia hasta trasplante hepático. Presentación del caso: Hombre de 24 años sin antecedentes que cursaba con un cuadro recurrente y agudizado de dolor abdominal asociado a cambios en la coloración en la orina, lesiones cutáneas, deposiciones diarreicas y distermias. Dentro de su abordaje con paraclínicos previos se descartaron causas de dolor abdominal recurrente iniciales, con porfobilinógeno negativo, y se completó el estudio con 5-aminolevulínico elevado, lo que configuró la clínica de porfiria por ALAD, con mejoría ante la hemoterapia y remisión de lesión renal aguda. Se documentó el distractor asociado posible de nefritis intersticial y manifestaciones en la piel derivadas del consumo de antiinflamatorios no esteroideos (AINE). Conclusiones: Se debe considerar la porfiria por ALAD y todas las porfirias hepáticas agudas en cualquier paciente que presente recurrencia inexplicable de dolor abdominal grave y neuropatía. A pesar de su relativa rareza y complejidad, la mayoría de las porfirias se pueden definir y diagnosticar fácilmente. Una de las causas más frecuentes en el retraso diagnóstico radica en no considerar este diagnóstico en los diferenciales de manera oportuna. Aún falta mucho por conocer de la porfiria por ALAD.

Abstract Introduction: Porphyrias are enzymatic disorders of heme synthesis. Acute hepatic porphyrias (AHP) presents with acute neurovisceral symptoms such as abdominal pain, nausea, vomiting, constipation, muscle weakness, neuropathy, tachycardia, and hypertension. 5-aminolevulinic acid dehydratase (ALAD) deficiency is a rare autosomal recessive disorder that results in little or no elevation of porphobilinogen but elevates urinary 5-aminolevulinic acid and coproporphyrin III. There are no records of this type of porphyria in Colombia. Acute management requires comprehensive care, ranging from hemotherapy to liver transplantation. Case Presentation: A 24-year-old man with no prior medical history presented with a recurrent and acute episode of abdominal pain associated with changes in urine color, skin lesions, diarrhea, and dysregulation of body temperature. Initial paraclinical workup ruled out common causes of recurrent abdominal pain, with a negative porphobilinogen test, but further testing revealed elevated 5-aminolevulinic acid, confirming the diagnosis of ALAD porphyria. The patient showed improvement with hemotherapy and remission of acute kidney injury. A possible distractor associated with interstitial nephritis and skin manifestations related to nonsteroidal anti-inflammatory drug (NSAID) use was documented. Conclusions: ALAD porphyria and all acute hepatic porphyrias should be considered in any patient presenting with unexplained recurrent severe abdominal pain and neuropathy. Despite their relative rarity and complexity, most porphyrias can be easily defined and diagnosed. A common cause of diagnostic delay is the failure to consider porphyria in the differential diagnosis on time. There is still much to learn about ALAD porphyria.

Resumen Introducción: El lupus eritematoso sistémico (LES) es una enfermedad autoinmune que causa inflamación sistémica y alteraciones en la tolerancia inmunológica. La activación de los genes inducibles por interferón (IFN), contribuye en más del 50% de su patogenia. Objetivo: relacionar el papel del IFN-λ en la patogenia del LES. Materiales y Métodos: Búsqueda sistémica en base de datos; a través de las palabras claves del MeSH and DeCS. Fue incluido adicionalmente la palabra “Interferón Lambda”. Resultados: Se encontró que la producción aberrante de interferón tipo I contribuye a la desregulación de IFN-λ, producido principalmente por células dendríticas plasmocitoides. Este proceso conduce a la estimulación inmunológica por autoanticuerpos y a un aumento de IFNλR-1 en células B, potenciando la generación de anticuerpos. IFN-λ3 se asocia particularmente con nefritis lúpica, y el IFN-λ en general aumenta la expresión de MHC-I, intensificando la respuesta de células T CD8+ y posiblemente afectando la tolerancia central y la regulación en el timo. Conclusión: Se destaca que el IFN-λ favorece la activación inmune, formación de inmunocomplejos, inflamación crónica y producción de autoanticuerpos, vinculándose niveles altos de IFN-λ3 con mayor actividad de la enfermedad.

Abstract Introduction: Systemic lupus erythematosus (SLE) is an autoimmune disease that causes systemic inflammation and alterations in immunological tolerance. The activation of interferon (IFN)-inducible genes contributes to more than 50% of its pathogenesis. Objective: to review the role of IFN-λ in the pathogenesis of SLE. Materials and Methods: Systemic search in database; through the MeSH and DeCS keywords. The word “Lambda Interferon” was additionally included. Results: Aberrant production of type I interferon was found to contribute to the deregulation of IFN-λ, produced mainly by plasmacytoid dendritic cells. This process leads to immunological stimulation by autoantibodies and an increase in IFNλR-1 in B cells, enhancing the generation of antibodies. IFN-λ3 is particularly associated with lupus nephritis, and IFN-λ generally increases MHC-I expression, enhancing the CD8+ T cell response and possibly affecting central tolerance and regulation in the thymus. Conclusion: It is highlighted that IFN-λ favors immune activation, formation of immune complexes, chronic inflammation and production of autoantibodies, linking high levels of IFN-λ3 with greater disease activity.

Abstract Henoch-Schonlein purpura nephritis (HSPN) is a systemic vascular inflammatory disease. Huanglian Decoction (HLD) ameliorates renal injury in nephritis; however, the mechanism of action of HLD on HSPN has not been investigated. This study aimed to investigate the protective mechanism of HLD treatment in HSPN. The effects of HLD on HSPN biochemical indices, kidney injury and NF-κB/NLRP3 signaling pathway were analyzed by biochemical analysis, ELISA, HE and PAS staining, immunohistochemistry, immunofluorescence, and Western Blot. In addition, the effects of HLD on HSPN cells were analyzed. We found that HLD treatment significantly reduced renal tissue damage, decreased the levels of IL-17, IL-18, TNF-α, and IL-1β, and increased the levels of TP and ALB in HSPN mice. It also inhibited the deposition of IgA, IgG, and C3 in kidney tissues and significantly decreased the expression of IκBα, p-IκBα, NLRP3, caspase-1, and IL-1β in kidney tissues and cells. In addition, PMA treatment inhibited the above-mentioned effects of HLD. These results suggested that HLD attenuates renal injury, IgA deposition, and inflammation in HSPN mice and its mechanism of action may be related to the inhibition of the NF-κB/NLRP3 pathway. HenochSchonlein Henoch Schonlein (HSPN disease (HLD however investigated indices NFκB/NLRP3 NFκBNLRP3 NFκBNLRP NF κB/NLRP3 κB NLRP3 NLRP NF-κB/NLRP analysis ELISA staining immunohistochemistry immunofluorescence Blot addition damage IL17, IL17 IL 17, 17 IL-17 IL18, IL18 18, 18 IL-18 TNFα, TNFα TNF α, α TNF-α IL1β, IL1β ILβ 1β, 1β β IgG C IκBα pIκBα, pIκBα p p-IκBα caspase1, caspase1 caspase 1, 1 caspase-1 abovementioned above mentioned NFκB NFκB/NLRP κBNLRP3 κBNLRP κB/NLRP IL1 IL-1 caspase- IL-

Abstract Objective To develop the second evidence-based Brazilian Society of Rheumatology consensus for diagnosis and treatment of lupus nephritis (LN). Methods Two methodologists and 20 rheumatologists from Lupus Comittee of Brazilian Society of Rheumatology participate in the development of this guideline. Fourteen PICO questions were defined and a systematic review was performed. Eligible randomized controlled trials were analyzed regarding complete renal remission, partial renal remission, serum creatinine, proteinuria, serum creatinine doubling, progression to end-stage renal disease, renal relapse, and severe adverse events (infections and mortality). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to develop these recommendations. Recommendations required ≥82% of agreement among the voting members and were classified as strongly in favor, weakly in favor, conditional, weakly against or strongly against a particular intervention. Other aspects of LN management (diagnosis, general principles of treatment, treatment of comorbidities and refractory cases) were evaluated through literature review and expert opinion. Results All SLE patients should undergo creatinine and urinalysis tests to assess renal involvement. Kidney biopsy is considered the gold standard for diagnosing LN but, if it is not available or there is a contraindication to the procedure, therapeutic decisions should be based on clinical and laboratory parameters. Fourteen recommendations were developed. Target Renal response (TRR) was defined as improvement or maintenance of renal function (±10% at baseline of treatment) combined with a decrease in 24-h proteinuria or 24-h UPCR of 25% at 3 months, a decrease of 50% at 6 months, and proteinuria < 0.8 g/24 h at 12 months. Hydroxychloroquine should be prescribed to all SLE patients, except in cases of contraindication. Glucocorticoids should be used at the lowest dose and for the minimal necessary period. In class III or IV (±V), mycophenolate (MMF), cyclophosphamide, MMF plus tacrolimus (TAC), MMF plus belimumab or TAC can be used as induction therapy. For maintenance therapy, MMF or azathioprine (AZA) are the first choice and TAC or cyclosporin or leflunomide can be used in patients who cannot use MMF or AZA. Rituximab can be prescribed in cases of refractory disease. In cases of failure in achieving TRR, it is important to assess adherence, immunosuppressant dosage, adjuvant therapy, comorbidities, and consider biopsy/rebiopsy. Conclusion This consensus provides evidence-based data to guide LN diagnosis and treatment, supporting the development of public and supplementary health policies in Brazil. evidencebased evidence LN. . (LN) 2 guideline performed remission doubling endstage end stage disease relapse infections mortality. mortality mortality) Assessment GRADE (GRADE 82 ≥82 favor conditional intervention diagnosis, (diagnosis opinion involvement but procedure parameters developed TRR (TRR ±10% 10 (±10 24h 24 25 months 50 08 0 8 0. g24 g g/2 1 period ±V, V ±V , (±V) MMF, (MMF) cyclophosphamide TAC, (TAC) therapy AZA (AZA adherence dosage biopsyrebiopsy rebiopsy biopsy/rebiopsy Brazil (LN ≥8 ±10 (±1 5 g2 g/ (±V (MMF (TAC ≥ ±1 (± ± (

Abstract Introduction Sjögren’s disease (SD) is an immune-mediated chronic inflammatory disease that affects epithelial tissues, mainly salivary and lacrimal glands. It also presents extraglandular manifestations. The main renal manifestation is tubulointerstitial nephritis (TIN), which can manifest as renal tubular acidosis (RTA). Urinary citrate may be a biomarker of RTA in these patients. The objective of this study was to evaluate whether hypocitraturia is a predictive biomarker of RTA in a sample of patients with SD in a tertiary hospital in southern Brazil. Methods All patients with SD who met the inclusion criteria and who participated in the rheumatology outpatient clinic of the Irmandade Santa Casa de Misericórdia de Porto Alegre were included. Demographic, SD, serological and urinary data were obtained. RTA was considered in those patients who persistently presented urinary pH above 5.5 and serum pH below 7.35. Patients who persistently had urinary pH above 5.5 underwent a urinary acidification test with furosemide and fludrocortisone. These patients received 1 mg of fludrocortisone and 40 mg of furosemide and had their urine samples tested 2, 4 and 6 h after taking the medications. The test was stopped at any urine sample with pH 5.5 or less. The variables were expressed as mean and standard deviation or interquartile range. The association between hypocitraturia and RTA was assessed using the chi-square. Results Forty-two patients were included, 95.2% female with a median age of 61.73 years. The prevalence of complete distal RTA was 4.88%. Twenty-eight patients underwent urine acidification testing. Five patients had hypocitraturia, and two of them had complete distal RTA. The association between hypocitraturia and RTA was statistically significant (p < 0.012), with a sensitivity of 100%, specificity of 91.2% and accuracy of 91.7%. The negative predictive value was 100%. The global renal assessment of the population demonstrated two patients with RTA, one patient with decreased renal function and six patients with proteinuria greater than 0.5 g/24 h. Conclusion The prevalence of RTA in the studied population was 4.88%. Hypocitraturia had high sensitivity and accuracy for the diagnosis of RTA. Sjögrens Sjögren s (SD immunemediated immune mediated tissues glands manifestations TIN, TIN , (TIN) . (RTA) Brazil included Demographic obtained 55 5 5. 735 7 35 7.35 2 medications less range chisquare. chisquare chi square. square chi-square Fortytwo Forty 952 95 95.2 6173 61 73 61.7 years 488 88 4.88% Twentyeight Twenty eight testing p 0.012, 0012 0.012 0 012 0.012) 100 100% 912 91 91.2 917 91.7% 05 0. g24 g 24 g/2 (TIN (RTA 3 7.3 9 95. 617 61. 48 8 4.88 001 0.01 01 10 91. 91.7 g2 g/ 7. 4.8 00 0.0 4.

Resumen: La vasculitis por IgA, es la vasculitis más frecuente en pediatría. Puede presentarse en adultos, con una clínica y evolución diferente y un pronóstico más grave que en los niños, incluida la progresión a enfermedad renal terminal. La historia natural de la enfermedad y de la nefritis, ha sido poco estudiada en adultos; no se dispone de criterios diagnósticos universalmente aceptados y el tratamiento es controvertido, dada la ausencia de estudios controlados, randomizados que lo avalen. Se reporta el caso de un paciente que presentó un síndrome purpúrico petequial, microhematuria, proteinuria y una evolución rápida a la insuficiencia renal, de cuyo estudio etiológico surge el diagnóstico de vasculitis por IgA del adulto.

Abstract: The IgA vasculitis is the most common vasculitis in Pediatrics. It can also present in adults but with a different clinical course and a worse prognosis, including the possibility of progression to end stage renal disease. The natural history of the disease and its nephritis have been scarcely studied in adults. There is no universal agreement in diagnostic criteria and the treatment is controversial given the absence of controlled randomized trials. We report the case of a patient who presented clinically with a petechial purpuric rash, microhematuria, proteinuria and rapid progression to renal failure that was diagnosed with IgA vasculitis in adult.

Resumo A vasculite por IgA é a vasculite mais comum em pediatria. Pode ocorrer em adultos, com apresentação e evolução clínica diferentes e prognóstico mais grave do que em crianças, incluindo progressão para doença renal terminal. A história natural da doença e da nefrite tem sido pouco estudada em adultos; Não existem critérios diagnósticos universalmente aceitos e o tratamento é controverso, dada a ausência de estudos controlados e randomizados que o apoiem. É relatado o caso de um paciente que apresentou síndrome purpúrica petequial, microhematúria, proteinúria e rápida evolução para insuficiência renal, de cujo estudo etiológico surge o diagnóstico de vasculite por IgA do adulto.

Introduction: The clinical forms of presentation of systemic lupus erythematosus (SLE) are varied, as well are the relapses that occur in the course of the disease. Objective: To describe the onset and relapses in a cohort of patients with SLE. Methodology. Observational, descriptive, cross-sectional study of patients with SLE who attended the National Hospital, during the period 2022 to 2023. The variables analyzed were sociodemographic, forms of onset and relapses. Results: 47 patients between 14 and 68 years of age (mean: 29.6 ±12 years) were included in the study, 91.5% female, 59.5% from the interior of the country, with secondary education (68.1%) and housewife occupation (55.3%). The duration of illness was on average 48.7 ±37.1 months. The most common form of onset was polyarthralgia (55.3%), followed by nephritis (27.7%). In relapse, nephritis was more frequent (44.7%), followed by polyarticular pain (40.4%). The most frequent cause of relapse was treatment abandonment (34.0%). Conclusion: The majority of patients were young women who presented the disease with arthralgia, followed by kidney involvement. Relapses presented with nephritis. The main cause of relapses were treatment abandonment.

Introducción. Las formas clínicas de presentación del lupus eritematoso sistémico (LES) son variadas, así como las recaídas que ocurren en el curso de la enfermedad. Objetivo. Describir las formas de presentación del debut y las recaídas de pacientes con LES. Metodología. Estudio observacional, descriptivo, de corte transversal, de pacientes con LES, que acudieron al Hospital Nacional, durante el periodo 2022 a 2023. Las variables analizadas fueron las variables sociodemográficas, clínicas y de laboratorio, al debut y durante las recaídas. Resultados. Se incluyeron 47 pacientes, entre 14 y 68 años de edad (media: 29,6 ±12 años), 91,5% del sexo femenino, 59,5% del interior del país, con educación secundaria (68,1%) y ocupación ama de casa (55,3%). El tiempo de enfermedad fue en promedio 48,7 ±37.1 meses. La forma más frecuente de debut fue la poli-artralgia (55,3%), seguido de nefritis (27,7%). En la recaída, la nefritis fue más frecuente (44,7%), seguida de dolor poliarticular (40,4%). La causa de recaída más frecuente fue el abandono del tratamiento (34,0%). Conclusión. La mayoría de las pacientes eran mujeres jóvenes que debutaron la enfermedad con artralgias, seguida de la afectación renal. Las recaídas se presentaron con nefritis. La causa principal de las recaídas fue el abandono del tratamiento.

ABSTRACT Introducción: Anti-C1q autoantibodies have been proposed as useful marker in systemic lupus erythematosus due to their association with lupus nephritis. Objective: To determine the prevalence of anti-C1q in patients with systemic lupus erythematosus and other rheumatic diseases to evaluate the association with lupus nephropathy. Methods: One hundred seventy-nine patients with systemic lupus erythematosus and 82 with other rheumatic diseases were included. Lupus nephritis was diagnosed in 70 (39%) of patients with systemic lupus erythematosus. Anti-C1q IgG antibodies were determined by ELISA. Associations were evaluated by logistic regression analysis. Results: The prevalence of anti-C1q was 37% (66/179) in patients with systemic lupus erythematosus and 9% (7/82) in controls (OR = 6.3; 95% CI 2.8-14). .1; p < 0.001). Anti-C1q was associated with proteinuria (OR = 2.6; 95% CI 1.2-6.0; p < 0.022); elevated erythrocyte sedimentation rate (OR = 3.2; 95% CI 1.5-6.7; p < 0.003) and anti-dsDNA (OR = 3.9; 95% CI 1.7-9.1; p < 0.002). In the logistic regression model adjusted for demographics and anti-dsDNA, although the OR of anti-C1q for nephritis was 2-fold higher than in the absence of anti-C1q, it only approached statistical significance. Simultaneous positivity of anti-C1q and anti-dsDNA was associated with lupus nephritis (OR = 4.3; 95% CI 1.9-9.5; p < 0.001). Conclusions: Anti-C1q occurred more frequently in patients with systemic lupus erythematosus than in controls. Anti-C1q combined with anti-dsDNA was strongly associated with lupus nephritis.

RESUMEN Introducción: Los autoanticuerpos anti-C1q han sido propuestos como un marcador útil en el lupus eritematoso sistémico por su asociación con la nefritis lúpica. Objetivo: Determinar la prevalencia de anti-C1q en pacientes con lupus eritematoso sistémico y otras enfermedades reumáticas para la evaluar la asociación con la nefropatía lúpica. Métodos: Se incluyeron 179 pacientes con lupus eritematoso sistémico y 82 con otras enfermedades reumáticas. La nefritis lúpica fue diagnosticada en 70 (39 %) de los pacientes con lupus eritematoso sistémico. Los anticuerpos anti-C1q IgG se determinaron por ELISA. Las asociaciones se evaluaron por análisis de regresión logística. Resultados: La prevalencia de anti-C1q fue de 37 % (66/179) en los pacientes con lupus eritematoso sistémico y de 9 % (7/82) en controles (OR = 6,3; IC 95 % 2,8-14,1; p < 0,001). El anti-C1q fue asociado con proteinuria (OR = 2,6; IC 95 % 1,2-6,0; p < 0,022); eritrosedimentación elevada (OR = 3,2; IC 95 % 1,5-6,7; p < 0,003) y anti-DNAdc (OR = 3,9; IC 95 % 1,7-9,1; p < 0,002). En el modelo de regresión logística ajustado para demografía y anti-DNAdc, aunque la OR del anti-C1q para la nefritis fue 2 veces más alta que en ausencia del anti-C1q, solo se aproximó a la significación estadística. La positividad simultánea de anti-C1q y anti-DNAdc estuvo asociada a la nefritis lúpica (OR = 4,3; IC 95 % 1,9-9,5; p < 0,001). Conclusiones: El anti-C1q se presentó con mayor frecuencia en pacientes con lupus eritematoso sistémico que en los controles. El anti-C1q combinado con anti-DNAdc resultó fuertemente asociado a la nefritis lúpica.

ABSTRACT Introduction: The Pan American Health Organization recognizes Chronic Kidney Disease of Nontraditional Causes as a serious form of kidney failure of uncertain etiology, which has reached devastating epidemic proportions in communities and saturation of health systems. Hypotheses related to infections, dehydration, global warming, hyperuricemia, exposure to agrochemicals or heavy metals and genetic susceptibility are mentioned, however, these hypotheses have not been conclusive. Objective: To carry out a systematic review on the relationship between non-traditional kidney disease and sociodemographic factors, agricultural exposure or heavy metals in the Latin American population. Methodology: An integrative systematic review was carried out under the PRISMA guide in the Medigraphic, BioMed Central, Wiley Online Library, Web of Science, ScienceDirect, PubMed and Scopus databases. With the keywords: kidney disease, nephritis, heavy metals, agrochemicals, risk factor. Of which 39 studies were included after evaluating their methodological quality. Results: it was found that 35.89% of the included studies had a high scientific rigor. Regarding the causes, it was found that exposure to agrochemicals was the most frequent cause of this disease. Conclusion: Heavy metals and agrochemicals have been shown to influence the development of Chronic Kidney Disease of Nontraditional Causes, however, most of the results are not generals and doesn´t demonstrate a statistically significant relationship. Sociodemographic factors have been little studied and more rigorous scientific research on this variable is required.

RESUMEN Introducción: La Organización Panamericana de la Salud reconoce a la Enfermedad Renal Crónica de Causas No Tradicionales como una forma grave de insuficiencia renal de etiología incierta, la cual ha alcanzado proporciones epidémicas en las comunidades y saturación de los sistemas de salud. La enfermedad se ha relacionado con infecciones, deshidratación, hiperuricemia, exposición a agroquímicos o metales pesados y susceptibilidad genética. Objetivo: Realizar una revisión integradora sobre la relación entre la enfermedad renal de causa no tradicional con factores sociodemográficos, exposición agrícola y metales pesados en población latinoamericana. Metodología: Se realizó una revisión sistemática integradora bajo la guía PRISMA en las bases de datos Medigraphic, BioMed Central, Wiley Online Library, Web of Science, ScienceDirect, PubMed y Scopus. Con las palabras claves: enfermedad renal, nefritis, metales pesados, agroquímicos, factor de riesgo. Se incluyeron 39 estudios después de evaluar la calidad metodológica de los mismos. Resultados: El 35,89% de los estudios incluídos tuvo una rigurosidad científica alta. Referente a las causas, se encontró que la exposición a agroquímicos fue la causa de mayor frecuencia en el padecimiento de esta enfermedad. Conclusión: Los metales pesados y agroquímicos han demostrado influir en el desarrollo de la Enfermedad Renal Crónica de causas no tradicionales, no obstante, la mayoría de los resultados de los artículos incluidos no tienen resultados generalizables ni estadísticamente significativos. Los factores sociodemográficos han sido poco estudiados y se requiere de mayor investigación con rigurosidad científica sobre esta variable.

ABSTRACT Pembrolizumab is an immune checkpoint inhibitor used as a cancer therapy. The incidence of immune related adverse events in patients receiving immune checkpoint inhibitors can be as high as 59%-85. Renal adverse effects are uncommon, but the incidence of kidney toxicity related to pembrolizumab is rising as the use of this agent becomes more frequent. We present an uncommon case of biopsy-proven acute interstitial nephritis secondary to pembrolizumab in a patient with metastatic squamous cell carcinoma at the time of his fourth scheduled cycle. Despite the good initial tumor response, pembrolizumab had to be suspended and the patient started on corticosteroids with an initial good response. On his own initiative, the patient stopped prednisolone early, leading to a rebound acute kidney injury. Pembrolizumab was not reintroduced for the risk of further renal function worsening. His clinical status declined due to the progression of the neoplastic disease, and he was referred for palliative care. This case illustrates the importance of systematizing some key points in the approach to acute interstitial nephritis secondary to pembrolizumab: the role of the differential diagnosis of acute kidney injury in a patient under an immune checkpoint inhibitor, the role of glucocorticoids and the controversy about rechallenging this drug after a related acute interstitial nephritis.

ABSTRACT Rituximab, a monoclonal antibody with the ability to bind itself to CD20, leads to a rapid depletion of B-cells (in around 24-72 hours), limiting antibody formation. The marker CD20 does not exist in any other cell type, which makes the action of rituximab specific. This antibody has been used in autoimmune entities such as rheumatoid arthritis and in hematological malignancies, but recently it has gained popularity as an important immunosuppressor in selected kidney diseases. In nephrology, this anti-CD20 antibody had its first indication in anti-neutrophil cytoplasmic antibody-associated vasculitis, but can now be used in primary membranous nephropathy, minimal change disease, lupus nephritis and others. There is also some data that indicates rituximab might have a promising role in other glomerular diseases in the future, but to date evidence is still lacking to recommend its widespread use. The aim of this document is to compile the most recent scientific evidence as to when rituximab should be used in the treatment of various glomerular diseases, and which other may come to benefit from it in the future.

RESUMEN Antecedentes: Además de las nefropatías diabéticas (DNP), también se conoce la prevalencia frecuente de nefropatías no diabéticas (NDNP) en pacientes diagnosticados con Diabetes mellitus tipo 2 (DM). El diagnóstico precoz de estas condiciones es importante para el tratamiento y pronóstico de estos pacientes. Objetivo: Este estudio tuvo como objetivo investigar las relaciones entre los hallazgos clínicos y de laboratorio de las biopsias renales de pacientes diabéticos tipo 2. Material y Métodos: Revisamos retrospectivamente las historias clínicas de 140 pacientes que tenían diagnóstico de DM tipo 2, desde julio de 2020 hasta agosto de 2022, y se les realizó biopsia renal en las clínicas de nefrología del Hospital Umraniye. Se revisaron los resultados de biopsia renal, presencia de hipertensión arterial, retinopatía diabética, hematuria y proteinuria así como también la duración de la enfermedad, las indicaciones de la biopsia, la hemoglobina glucosilada (HbA1c), la creatinina sérica, el nitrógeno ureico en sangre, la albúmina y los niveles de proteinuria en orina de 24 h. El nivel de significación estadística se determinó como p<0,05. Resultados: se detectaron NDNP en el 43,7% de los pacientes. Entre estos, el diagnóstico más común fue la nefritis intersticial (20%). La indicación de biopsia más frecuente resultó ser la proteinuria en rango nefrótico (30,7%). La diferencia entre las indicaciones de biopsia renal de los pacientes DNP y NDNP fue estadísticamente significativa (p<0,001). Los pacientes con DNP tuvieron una mayor incidencia de retinopatía (60%, 11%, p<0,001). Se detectó una diferencia estadísticamente significativa entre la duración de la enfermedad de los grupos DNP y NDNP (11,23 +5,74 años, p:0,002). De acuerdo con el análisis de regresión multivariado, la presencia de DR y el valor de HbA1c en más del 7% tienen 4,482 y 4,591 veces mayor riesgo de incidencia de DNP (p = 0,021, p: 0,024). Conclusión: El diagnóstico precoz de DNP y NDNP de pacientes diabéticos mediante la realización de biopsias renales afecta el tratamiento y pronóstico de los pacientes. Por lo tanto, al evaluar pacientes diabéticos, es necesario no pasar por alto los hallazgos sugestivos de NDNP.

ABSTRACT Background: In addition to diabetic nephropathies (DNP), prevalence of nondiabetic nephropathies (NDNP) is also known to be frequent in patients diagnosed with type 2 Diabetes mellitus (DM). Early diagnosis of these conditions is important for the treatment and prognosis of these patients. Aim: This study aimed to investigate the relationships between clinical and laboratory findings of type 2 diabetic patients’ renal biopsies. Material and Methods: We retrospectively reviewed the medical records of 140 patients who had diagnosis of type 2 DM and underwent renal biopsy from July 2020- August 2022 at nephrology clinics of Hospital Umraniye. Renal biopsy results, presence of hypertension, diabetic retinopathy, hematuria, proteinuria; duration of the disease, biopsy indications, glycated hemoglobin (HbA1c), serum creatinine, blood urea nitrogen, albumin, and proteinuria levels in 24h urine were measured. The statistical significance level was determined as p<0,05. Results: NDNP were detected in 43,7% of the patients. Among these the most common diagnosis was interstitial nephritis (20%). The most common biopsy indication was found to be nephrotic range proteinuria (30,7%). The difference between the DNP and NDNP patients’ renal biopsy indications was statistically significant (p<0,001). DNP patients had a higher retinopathy incidence (60%,11%, p<0,001). A statistically significant difference was detected between the disease duration of DNP and NDNP groups (11,23 +5,74 years, p:0,002). According to multivariate regression analysis DR and HbA1c value, more than 7% have 4, 482 and 4,591-fold increased the risk of DNP incidence (p=0,021, p:0,024). Conclusion: Early diagnosis of DNP and NDNP of diabetic patients by performing renal biopsies affects the treatment and prognosis of the patients. Therefore, when evaluating diabetic patients, its necessary not to overlook the findings suggestive of NDNP.