Abstract INTRODUCTION During the pandemic caused by the SARS-CoV-2 virus, some patients who develop severe forms of COVID-19 present thrombotic microangiopathy in the course of the disease’s clinical progression. METHODS Data came from direct patient observation and clinical records. We performed a kidney biopsy and used optical microscopy and immunofluorescence techniques. RESULTS We present the case of a 78-year-old male patient, mestizo, overweight with a history of high blood pressure, ischemic cardiopathy and chronic obstructive pulmonary disease who was first admitted to the hospital due to respiratory symptoms and diarrhea related to COVID-19, from which he recovered. He was subsequently readmitted with symptoms of acute renal dysfunction accompanied by mild anemia and thrombocytopenia; at the same time, he resulted negative for COVID-19 via a real-time polymerase chain reaction test. A kidney biopsy revealed thrombi in glomerular capillaries, acute tubular necrosis, thickening of extraglomerular blood vessel walls, and C3 deposits in the glomerular tufts. CONCLUSIONS We describe a case of thrombotic microangiopathy with kidney biopsy in a patient recovering from COVID-19. Acute renal dysfunction is a form of thrombotic microangiopathy that has been observed in patients recovering from COVID-19.

Introduction: the recurrence of urinary lithiasis is a health problem needing the implementation of preventive strategies, thus knowing the frequency of the different renal metabolic disorders is essential. Objectives: To identify the most common metabolic disorders in urinary lithiasic disease and their relationship with patient characteristics. Methods: an analytical, cross-sectional study was conducted in 3655 adult patients with urolithiasis. A renal metabolic study was conducted at the Institute of Nephrology from 2003 to 2009. The analytical determinations were performed by spectrophotometric technique according to the standards of service. All information is processed using SPSS version 15.0. The technique of frequency distribution analysis was used. Relationships between variables were identified by the test of independence. Results: The main metabolic disorders found were: hyperuricemia (48.2%), hypercalciuria (45.1%), and urinary tract infection (16.2 %). Hypercalciuria and hyperuricosuria were less frequent in subjects older than 42 years (p= 0.01). Hypercalciuria, hyperoxaluria and hyperuricosuria were more frequent in men (p= 0.00), while hypocitraturia was more frequent in women (p= 0.04). Hyperuricosuria was found more frequently in overweight and obese patients (p= 0.00), and hyperoxaluria was more frequent among overweight subjects (p= 0.01). Conclusions: In patients with renal lithiasis the most common metabolic disorders are hyperuricemia, hypercalciuria, and urinary tract infection. All subjects younger than 43 years suffered hypercalciuria and hyperuricosuria. Men have higher frequency of hypercalciuria, hyperuricosuria and hyperoxaluria. Women have higher frequency of hypocitraturia. The frequency of submission of hyperoxaluria, hyperuricosuria and hypocitraturia is related to the nutritional status of these subjects.

Introducción: las litiasis urinarias constituyen un problema de salud. La recurrencia de ellas hace necesario implementar estrategias preventivas, para lo cual es indispensable conocer la frecuencia de los diferentes trastornos metabólicos renales. Objetivos: identificar los disturbios metabólicos más frecuentes en la enfermedad litiásica urinaria y la posible relación de estos con características de los pacientes. Métodos: estudio observacional analítico, transversal. Se estudiaron 3 655 pacientes adultos con litiasis urinaria, que se realizaron estudio metabólico renal en el Instituto de Nefrología entre los años 2003 y 2009. Las determinaciones analíticas fueron realizadas por técnica espectrofotométrica, según las normas del servicio. Toda la información se procesó mediante el paquete estadístico SPSS versión 15.0. Se utilizó la técnica de análisis de distribución de frecuencias. Las relaciones entre las variables se identificaron mediante el test de independencia. Resultados: los principales trastornos metabólicos encontrados fueron: hiperuricemia (48,2 %), hipercalciuria (45,1 %) e infección del tracto urinario (16,2 %). La hipercalciuria y la hiperuricosuria fueron menos frecuentes en los sujetos mayores de 42 años (p= 0,01). La hipercalciuria, la hiperoxaluria y la hiperuricosuria resultaron más frecuentes en los hombres (p= 0,00), mientras la hipocitraturia tuvo mayor frecuencia en las mujeres (p= 0,04). La hiperuricosuria se encontró con mayor frecuencia en pacientes sobrepesos y obesos (p= 0,00), y la hiperoxaluria fue más frecuente entre los sobrepesos (p= 0,01). Conclusiones: en los pacientes con litiasis renal los trastornos metabólicos más frecuentes son hiperuricemia, hipercalciuria e infección del tracto urinario. Los menores de 43 años tienen más hipercalciuria e hiperuricosuria. Los hombres tienen mayor frecuencia de hipercalciuria, hiperoxaluria e hiperuricosuria y las mujeres, de hipocitraturia. La frecuencia de presentación de hiperoxaluria, hiperuricosuria e hipocitraturia se encuentra relacionada con el estado nutricional de los sujetos.