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: Anti-insulin autoantibodies (AAI) represent a serological marker of type 1 diabetes (T1D). The clinical significance of AAIs has not yet been determined in the Cuban population. Objective: To determine the clinical value of AAI in patients with T1D. Methods: AAI serum levels were determined by enzyme-linked immunosorbent assay (ELISA) in 33 adult patients with T1D, 78 patients with other endocrine conditions (CEE) such as type 2 diabetes, Hashimoto's thyroiditis, and hyperinsulinemia, and 49 normal controls (CN). The cut-off value was determined by receiver operating characteristic (ROC) curve analysis. Nonparametric tests were used to compare the AAI levels of patients with T1D, CEE, and CN, and to determine the correlation between AAI and age. Results: AAI optimal cut-off value for T1D was the index of 1.05, with 45.5% of sensitivity, 81.6% specificity, 2.47 positive likelihood ratio, and 0.67 negative likelihood ratio. AAI levels in DT1 (index of 0.97) were significant, higher than those of CN (index of 0.70; p= 0.020) and CEE levels (index of 0.63; p= 0.009). AAI levels were inversely proportional to age in diabetic patients (ρ = -0.252; p=0.030). Conclusions: Patients with T1D were distinguished by AAI higher levels, although the presence of these antibodies was not exclusive to T1D. AAI levels depended on age in diabetic patients.

RESUMEN Introducción: Los autoanticuerpos anti-insulina (AAI) representan un marcador serológico de la diabetes tipo 1 (DT1). El significado clínico de los AAI aún no ha sido determinado en la población cubana. Objetivo: Determinar el valor clínico de AAI en pacientes con DT1. Métodos: Se determinaron los niveles séricos de AAI por el ensayo inmuno-adsorbente ligado a enzima (ELISA) en 33 pacientes adultos con DT1, 78 pacientes con otras condiciones endocrinas (CEE) como diabetes tipo 2, tiroiditis de Hashimoto e hiperinsulinemia, y 49 controles normales (CN). El valor de corte se determinó con el análisis de las curvas características operativas del receptor (COR) (ROC por sus siglas en inglés). Se utilizaron pruebas no paramétricas para comparar los niveles de AAI de pacientes con DT1, CEE y CN, y determinar la correlación entre AAI y la edad. Resultados: El valor de corte óptimo de AAI para DT1 fue el índice de 1,05, con sensibilidad de 45,5 %, especificidad de 81,6 %, razón de verosimilitud positiva de 2,47, y razón de verosimilitud negativa de 0,67. Los niveles de AAI en DT1 (índice de 0,97) fueron significativo, más altos que los de CN (índice de 0,70; p=0,020) y los de CEE (índice de 0,63; p= 0,009). Los niveles de AAI resultaron inversamente proporcionales a la edad en pacientes diabéticos ( =-0,252; p=0,030). Conclusiones: Los pacientes con DT1 se distinguieron por niveles más altos de AAI, aunque la presencia de estos anticuerpos no fue exclusiva de DT1. Los niveles de AAI dependieron de la edad en los pacientes diabéticos.

ABSTRACT Introduction: Idiopathic inflammatory myopathies constitute a group of muscle diseases characterized by chronic muscle weakness and muscle inflammation of unknown etiology. Objective: To identify the clinical and immunological characteristics and their relationship with organ damage in patients with idiopathic inflammatory myopathies. Methods: An observational, descriptive, cross-sectional study was carried out in 52 patients with diagnosis of idiopathic inflammatory myopathy, followed in the protocolized consultation of Rheumatology at Hermanos Ameijeiras Clinical and Surgical Hospital from January 2016 to January 2017. For the qualitative variables, the percentages of each group were calculated. Pearson's Chi-square (Fisher's exact statistic) was used. 95% significance level (α = 0.05) was used to relate the presence of antibodies and the type of myopathy as well as the presence of clinical manifestations of MII. Results: 80.8% were women and 86.5% of urban origin. The mean age at the beginning was 42.8 ± 13.2 years, time delay to diagnosis was 8.8 ± 7.0 months, mean time of evolution of the disease of 7.5 ± 7.1 years. 80.8% were in remission, 50% had specific antibodies. Hypertension was found in 28.8% of the patients and 23.1% had interstitial pneumonia. Arthritis was present in 96.2%. 26.9% had specific Jo1 antibodies and 21.2% had Ro 52. Conclusions: Urban female patients in the fourth decade of life predominated, the most frequent specific antibodies found was anti-Jo-1, associated with the presence of interstitial lung disease.

RESUMEN Introducción: Las miopatías inflamatorias idiopáticas constituyen un grupo de enfermedades musculares caracterizadas por debilidad muscular crónica e inflamación muscular de etiología desconocida. Objetivo: Identificar las características clínicas e inmunológicas y su relación con el daño de órganos en los pacientes con miopatías inflamatorias idiopáticas. Métodos: Se realizó estudio observacional, descriptivo, transversal, en 52 pacientes con diagnóstico de miopatía inflamatoria idiopática, seguidos en la consulta protocolizada de Reumatología del Hospital Clínico Quirúrgico “Hermanos Ameijeiras” entre enero 2016 y enero 2017. Para las variables cualitativas se calcularon los porcentajes de cada grupo. Se utilizó Chi-cuadrado de Pearson (estadístico exacto de Fisher). Nivel de significación del 95 % (α = 0,05) para relacionar la presencia de anticuerpos y el tipo de miopatía así como la presencia de manifestaciones clínicas de MII. Resultados: El 80,8 % fueron mujeres y 86,5 % de procedencia urbana. La edad media al comienzo fue 42,8 ± 13,2 años, tiempo de demora al diagnóstico de 8,8 ± 7,0 meses, tiempo medio de evolución de la enfermedad de 7,5 ± 7,1 años. El 80,8 % estaba en remisión, 50 % tenía anticuerpos específicos. La hipertensión arterial se encontró en 28,8 % de los pacientes y 23,1 % presentó neumonía intersticial. La artritis estuvo presente en 96,2 %. El 26,9 % presentaron anticuerpos específicos Jo-1 y 21,2 % Ro 52. Conclusiones: Predominaron los pacientes del sexo femenino en la cuarta década de la vida de procedencia urbana, los anticuerpos específicos encontrados más frecuentes fue el anti Jo-1, asociado a la presencia de neumopatía intersticial.

ABSTRACT Introduction: Rheumatoid arthritis within its expression as a systemic inflammatory disease presents extra-articular manifestations. Objectives: To determine the frequency of extra-articular manifestations in patients with rheumatoid arthritis, to identify the most frequent and their association with antibodies against citrullinated cyclic peptides. Methods: A descriptive and cross-sectional study was carried out in 101 patients with a diagnosis of rheumatoid arthritis, assisted in the protocolized consultation of Rheumatology service at Hermanos Ameijeiras Clinical Surgical Hospital, from August to December 2019. Sociodemographic characteristics were identified, such as age, sex, time of evolution of rheumatoid arthritis, smoking habits. The presence of extra-articular manifestations was searched for by questioning, physical examination and with the help of complementary tests, and the titers of antibodies against citrullinated cyclic peptides were determined in the plasma of the patients. Results: Extra-articular manifestations were present in 38 patients, 37.6% of the cases, the most frequent were subcutaneous nodules in 37 patients, and anemia in 35, which constituted 36.6% and 34.7% of the cases, respectively. Seventy eight patients were positive for citrullinated cyclic antipeptides, 77.2% of the sample, there was no association between the presence of citrullinated cyclic antipeptides and the activity of the disease. There was no significant association between the presence of these antibodies and the presence of extra-articular manifestations p <0.0001, the association between the levels of citrullinated cyclic antipeptides and the number of extra-articular manifestations in a patient was significant p=0.0018. Conclusions: The existing joint manifestations in the studied patients were significantly associated with the presence of citrullinated cyclic antipeptides.

RESUMEN Introducción: La artritis reumatoide se manifiesta como enfermedad inflamatoria sistémica presenta manifestaciones extrarticulares. Objetivos: Determinar la frecuencia de manifestaciones extrarticulares en pacientes con artritis reumatoide, identificar las más frecuentes y su asociación con anticuerpos contra péptidos cíclicos citrulinados. Métodos: Se realizó un estudio descriptivo y transversal, en 101 pacientes con diagnóstico de artritis reumatoide, atendidos en La Consulta Protocolizada del Servicio de Reumatología del Hospital Clínico Quirúrgico “Hermanos Ameijeiras”, entre agosto y diciembre del año 2019. Se identificaron características sociodemográficas como edad, sexo, tiempo de evolución de la artritis reumatoide y tabaquismo. Se buscaron presencia de manifestaciones extrarticulares por el interrogatorio, examen físico y con ayuda de exámenes complementarios y se determinaron los títulos de anticuerpos contra péptidos cíclicos citrulinados en el plasma de los pacientes. Resultados: Las manifestaciones extrarticulares estuvieron presentes en 38 pacientes para 37,6 % de los casos, las más frecuentes fueron los nódulos subcutáneos 37 pacientes, y la anemia en 35 que constituyen 36,6 % y 34,7 % de los casos, respectivamente. Fueron positivos a antipéptidos cíclicos citrulinados 78 enfermos, 77,2 % de la muestra, no existió asociación entre presencia de los antipéptidos cíclicos citrulinados y la actividad de la enfermedad. No existió asociación significativa entre estos anticuerpos y las manifestaciones extrarticulares p<0,0001. Fue significativa la asociación entre los niveles de antipéptidos cíclicos citrulinados y el número de manifestaciones extrarticulares en un paciente p=0,0018. Conclusiones: Las manifestaciones articulares existentes en los pacientes estudiados se asociaron, significativamente, con la presencia de los antipéptidos cíclicos citrulinados.

ABSTRACT Introduction: Idiopathic inflammatory myopathies constitute a group of muscle diseases characterized by chronic muscle weakness and muscle inflammation of unknown etiology. Objective: To identify the clinical and immunological characteristics and organ damage in patients with idiopathic inflammatory myopathies. Method: An observational, descriptive, cross-sectional study was carried out in 52 patients with diagnosis of idiopathic inflammatory myopathy, followed up in the protocolized service of Rheumatology at Hermanos Ameijeiras Clinical Surgical Hospital from January 2016 to January 2017. The qualitative variables were calculated with the percentages in each group. Pearson's Chi-square (Fisher's exact statistic) (95% significance level (α = 0.05) was used to relate the presence of antibodies and the type of myopathy as well as the presence of clinical manifestations of idiopathic inflammatory myopathies. Results: 80.8% were women of the total patients studied, 61.5% non-white skin color, 86.5% of urban origin. The mean age at the beginning was 42.8 ± 13.2 years, time delay to diagnosis was 8.8 ± 7.0 months, mean time of evolution of the disease of 7.5 ± 7.1 years. 80.8% were in remission, 50% had specific antibodies. Hypertension was found in 28.8% of the patients and 23.1% had interstitial pneumonia. Arthritis was present in 96.2%. We found 26.9% had specific Jo1 antibodies and 21.2% Ro 52. Conclusions: Urban origin female patients predominated, in their fourth decade of life, the more frequent specific antibodies found was anti Jo-1, which was associated with the presence of interstitial lung disease.

RESUMEN Introducción: Las miopatías inflamatorias idiopáticas constituyen un grupo de enfermedades musculares caracterizadas por debilidad muscular crónica e inflamación muscular de etiología desconocida. Objetivo: Identificar las características clínicas e inmunológicas y daño de órganos en pacientes con miopatías inflamatorias idiopáticas. Método: Se realizó estudio observacional, descriptivo, transversal en 52 pacientes con diagnóstico de miopatía inflamatoria idiopática, seguidos en la consulta protocolizada de Reumatología del Hospital Clínico Quirúrgico “Hermanos Ameijeiras” entre enero 2016 y enero 2017. Para las variables cualitativas se calcularon los porcentajes de cada grupo. Se utilizó Chi-cuadrado de Pearson (Estadístico exacto de Fisher), nivel de significación del 95 % (α=0,05) para relacionar la presencia de anticuerpos y el tipo de miopatía, así como la presencia de manifestaciones clínicas de miopatías inflamatorias idiopáticas. Resultados: Del total de pacientes estudiadas, 80,8 % fueron mujeres, 61,5 % de color de piel negra, 86,5 % de procedencia urbana. La edad media al comienzo fue 42,8 ± 13,2 años, tiempo de demora al diagnóstico de 8,8 ± 7,0 meses, tiempo medio de evolución de la enfermedad de 7,5 ± 7,1 años, 80,8 % estaban en remisión, 50 % tenía anticuerpos específicos. La hipertensión arterial se encontró en 28,8 % de los pacientes y 23,1 % presentó neumonía intersticial. La artritis estuvo presente en 96,2 %, 26,9 % presentaron anticuerpos específicos Jo1 y 21,2 % Ro 52. Conclusiones: Predominaron los pacientes del sexo femenino, en la cuarta década de la vida, de procedencia urbana. Los anticuerpos específicos encontrado con más frecuencia fue el anti Jo-1, que se asoció a la presencia de neumopatía intersticial.

ABSTRACT INTRODUCTION Double-negative T lymphocytes act as immunomodulators in immune response. This subpopulation is rare in blood but important in the immunopathogenesis of autoimmune diseases, viral infections, cancer and transplant rejection. These disorders have been studied in Cuba using flow cytometry, but normal values of these cells have not yet been established. OBJECTIVE Estimate preliminary reference values for double-negative T lymphocytes according to sex and age in Cuban adults. METHODS A cross-sectional study was carried out in a population of 182 healthy adult residents of Havana: 93 women and 89 men aged 18–80 years with no chronic diseases, toxic habits (smoking, excessive alcohol or caffeine intake) or medications that might alter quantity or functioning of immune-system cells. Peripheral blood was drawn to determine immunophenotype with monoclonal antibodies. The phenotype of double-negative T lymphocytes was quantified as CD45+/CD3+/CD4-/CD8-/CD56- using a Gallios flow cytometer (Beckman-Coulter, France). Medians and ranges (to the 5th and 95th percentiles) were calculated for sex and age, for both percentages and absolute values. To evaluate the effects of sex and age, both variables as well as their interaction were included in a linear model. RESULTS Respective median and range values were total percentage values 3.4 (1.6–7.4) and total absolute values (cells/μL) 57.5 (23.0–157.0). The effect of age on lymphocyte values (percentage and absolute) was significant, with lower numbers in the 51–80 years' age group (p <0.001). Percentage values according to age group were: 18–25 years, 3.8 (2.2–7.4); 26–50 years, 3.7 (1.7–8.7); and 51–80 years 2.6 (1.3–6.6). Absolute values by age group were: 18–25 years, 90 (32.6–163.7); 26–50 years, 65 (28.8–184.0); and 51–80 years 38.5 (17.9–90.1). Desegregating data by sex and age: percentage of women aged 18–25 years 5.2 (2.1–7.8), 26–50 years 4.0 (1.8–7.7), and 51–80 years 2.5 (1.3–5.8); percentage of men aged 18–25 years 3.4 (2.3–7.3), 26–50 years 3.8 (1.5–8.7), and 51–80 years 2.6 (1.2–7.3). Absolute values: women aged 18–25 years 112.0 (40.0–153.1), 26–50 years 67.0 (26.7–138.3), and 51–80 years 40 (18.6–92.0); and men aged 18–25 years 71.5 (32.1–166.7), 26–50 years 61.5 (29.9–188.7), and 51–80 years 36 (13.5–81.7). The low sex*age interaction confirms these differences occur in both men and women. Values decrease with age, with a more abrupt fall starting at 50 years. CONCLUSIONS Estimated reference values were determined for absolute values and relative proportions of double-negative T lymphocytes in healthy Cuban adults according to sex and age. Age was found to have a significant effect.

ABSTRACT Introduction: Biomarkers are essential in the diagnosis and prognosis of systemic erythematous lupus in which clinical manifestations are extremely complex and heterogeneous. Objective: To determine the clinical value of circulating immunocomplexes in patients with systemic erythematous lupus. Methods: Serum levels of C1q-binding immunocomplexes and anti-double-stranded deoxyribonucleic acid (anti-dsDNA), anti-nucleosome (anti-Nuc) and anti-ribosomal proteins (anti-RibP) were determined by enzyme-linked immunosorbent assay (ELISA) in 93 patients diagnosed with systemic lupus erythematosus. Nonparametric tests were used to test the association between immunocomplexes and auto-antibodies. The frequency of lupus nephritis in the circulating immunocomplex positive and negative patient groups was compared using Chi square. Results: Immunocomplexes were found in 24 (25.8%) patients with systemic lupus erythematosus. The patients with the highest immunocomplex titers were positive for the three autoantibodies used (p = 0.044). A direct correlation was found between the levels of anti-RibP and immunocomplexes (Rho = 0.303, p = 0.003) and between anti-dsDNA and anti-Nuc (Rho = 0.449, p = 0.001). Lupus nephritis occurred in 58.3% of immunocomplex patients, and 31.9% immunocomplex negative patients (p = 0.213). Conclusions: Circulating immunocomplexes characterized a smaller fraction of patients with systemic lupus erythematosus. Their presence was not associated with anti-dsDNA antibodies or lupus nephritis.

RESUMEN Introducción: Los biomarcadores son claves en el diagnóstico y pronóstico del lupus eritematoso sistémico en el cual las manifestaciones clínicas son extremadamente complejas y heterogéneas. Objetivo: Determinar el valor clínico de los inmunocomplejos circulantes en pacientes con lupus eritematosos sistémico. Métodos: Se determinaron los niveles séricos de inmunocomplejos fijadores del C1q y de los anticuerpos anti-ácido desoxirribonucleico de doble cadena (anti-ADNdc), anti-nucleosoma (anti-Nuc) y anti-proteínas ribosomales (anti-RibP) por el ensayo inmuno-adsorbente ligado a enzima (ELISA) en 93 pacientes con diagnóstico de lupus eritematosos sistémico. Se utilizaron exámenes no paramétricos para probar la asociación entre los inmunocomplejos y los auto-anticuerpos. La frecuencia de nefritis lupica en los grupos de pacientes positivos y negativos de inmunocomplejos circulantes se comparó mediante Chi cuadrado. Resultados: Los inmunocomplejos se encontraron en 24 (25,8 %) pacientes con lupus eritematosos sistémico. Los pacientes que presentaron los títulos más altos de inmunocomplejos fueron los positivos a los tres auto-anticuerpos usados (p=0,044). Se encontró correlación directa entre los niveles de anti-RibP y los inmunocomplejos (Rho=0,303, p=0,003) y entre los anti-ADNdc y anti-Nuc (Rho=0,449, p=0,001). La nefritis lúpica se presentó en 58,3 % de pacientes con inmunocomplejos, y 31,9 % pacientes negativos de inmunocomplejos (p=0,213). Conclusiones: Los inmunocomplejos circulantes caracterizaron una fracción menor de pacientes con lupus eritematosos sistémico. La presencia de estos no se asoció a los anticuerpos anti-ADNdc ni a la nefritis lupica.

ABSTRACT Introduction: Celiac disease is a caused by a permanent sensitivity to gluten, which results mainly in functional disorders of the small intestine. To successfully diagnose of celiac disease, it is necessary to properly convey four criteria: clinic, histological, serological and molecular. The insufficient utilization of them in the medical practice could conduce to false diagnosis of celiac disease. Objective: To demonstrate the occurrence of mistaken diagnoses of celiac disease when the four criteria are not properly addressed. Methods: Forty-six children were diagnosed with celiac disease based on clinical and histopathological criteria and remitted to the “Hermanos Ameijeiras” Hospital´s Molecular Genetics service. In order to complete the serological and molecular diagnosis procedure, there were detected antitransglutaminase antibodies after gluten ingestion, and HLA DQ2/HLA DQ8 alleles in every child. Individuals who met the four criteria were considered celiac disease patients. Results: The analysis of 46 patients showed that 13 (28.3%) where negative to the presence of both allele HLA DQ2/HLA DQ8, and hence negative for celiac disease diagnosis. Eight patients (17.39%) where HLA DQ2/HLA DQ8 positive and antitransglutaminase antibodies negative, so they were considered as negative for diagnosis of celiac disease. According to our results, 21 patients (45.7%) were mistakenly diagnosed. The remaining 25 patients (54.3%) where positive for all diagnosis criteria. Conclusions: In order to successfully diagnose of celiac disease, in addition to clinical and histopathological tools used in the network of pediatrics hospitals in the country, it is necessary to include the serological and molecular method.

RESUMEN Introducción: La enfermedad celiaca es el resultado de una sensibilidad permanente al gluten. Puede conducir principalmente a trastornos intestinales. Cuatro criterios son utilizados para el diagnóstico de esta enfermedad: clínicos, histológicos, serológicos y moleculares. La insuficiente utilización de estos criterios conduce a falsos diagnósticos de dicha enfermedad. Objetivo: Demostrar la existencia de falsos diagnósticos de enfermedad celiaca cuando no se utilizan las herramientas necesarias para ello. Métodos: Se estudiaron 46 niños que fueron remitidos al Servicio de Genética Molecular del Hospital “Hermanos Ameijeiras” con diagnóstico de enfermedad celiaca basado en criterios clínicos e histopatológicos. Para completar los procederes diagnósticos, a cada paciente se le determinó anticuerpos antitransglutaminasa previa ingesta de gluten, y los alelos HLA DQ2 y HLA DQ8. Se consideraron pacientes con enfermedad celiaca aquellos casos que cumplieron los cuatro criterios. Resultados: De los 46 pacientes, trece (28,3 %) fueron negativos a los alelos HLA DQ2/HLA DQ8, lo que niega estén padeciendo de enfermedad celiaca; ocho (17,39 %) fueron positivos a los alelos HLA y negativos a la presencia de anticuerpos, lo que también niega la enfermedad. Es decir, 21 (45,7 %) eran falsos diagnósticos de enfermedad celiaca. Los 25 (54,3 %) restantes, además de los criterios con que fueron remitidos, cumplieron los serológicos (positividad a anticuerpos antitransglutaminasa) y moleculares (positividad para moléculas HLA DQ2/HLADQ8). Conclusiones: Para un diagnóstico de certeza de enfermedad celiaca es necesario, además de las herramientas clínicas e histopatológicas utilizadas en la red de hospitales pediátricos del país, el uso de procederes serológicos y moleculares.

ABSTRACT INTRODUCTION Quantification of lymphocyte subpopulations is useful for evaluating immune response in states of health and disease, including immunodeficiencies, autoimmunity, infections and cancer. Studies have found that concentrations and proportions of different cell subpopulations vary with geographic location, age, sex and ethnicity. Knowing the normal values of these cells and their variation in healthy populations will contribute to improved clinical practice and scientific research. OBJECTIVE Estimate normal absolute concentrations and percentages of the most abundant lymphocyte subpopulations in peripheral blood and their relation to sex and age. METHODS A cross-sectional analysis was conducted in 129 healthy adults, 61 men and 68 women aged 18–80 years; 89 aged <50 years and 40 ≥50 years. We included individuals who agreed to participate by written informed consent. Exclusion criteria were chronic disease, or use of tobacco, alcohol or medications that can alter immune system cell numbers and functions. Through dual platform flow cytometry, we determined absolute and percentage values for T lymphocyte subsets CD3+, CD3+/CD4+T, CD3+/CD8+T, CD19+ B cells and CD3-/CD56+ natural killer cells in peripheral blood, using an 8-color flow cytometer. We estimated medians and the 2.5 and 97.5 percentiles and calculated the Pearson correlation coefficient to evaluate associations. Significance tests were also used to compare groups. The significance threshold was p = 0.05 in all cases. RESULTS Ranges of absolute values and percentages (%) were: total lymphocytes: 1200–3475 cells/μL (20.2–49.3); CD3+ T cells: 880–2623 cells/μL (56.5–84.7); CD3+/CD4+ T cells: 479–1792 cells/μL (30.3–55.7); CD3+/CD8+ T cells: 248–1101 cells/μL (13.2–42.9); CD19+ B cells: 114– 1491 cells/μL (5.4–49.5); CD3-/CD56+ natural killer cells: 70–652 cells/μL (3.7–28.0); and the CD4+:CD8+ index: 0.80–3.92. Absolute numbers–– but not percentages––of lymphocytes and CD3+ T cells were higher in those <50 years (p = 0.025 and 0.020, respectively). Absolute values and relative percentages of CD3+/CD8+ and relative values of CD3+/CD4+ T cells were significantly higher in the younger subgroup (p = 0.004 and p = 0.047). Age was not associated significantly with B lymphocytes or natural killer cells. Absolute and relative values of CD3+/CD4+ T lymphocytes were significantly higher in women (p = 0.009 and 0.036, respectively). CONCLUSIONS Absolute numbers of total lymphocytes and T and CD3+/CD8+ T lymphocytes are higher in younger individuals. In percentage values, CD3+/CD4+ T lymphocytes are lower in older persons. Absolute and percentage values of CD3+/CD4+ T phenotype are higher in women. These differences justify adjusting clinical analyses to different values by age and sex.

ABSTRACT INTRODUCTION Flow cytometry allows immunophenotypic characterization of important lymphocyte subpopulations for diagnosis of diseases such as cancer, autoimmune diseases, immunodeficiencies and some infections. Normal values of rare lymphoid cells in blood, quantified by cytometry, vary among different populations; so it is indispensable to obtain normal national values that can be used in clinical practice. OBJECTIVE Characterize distribution of rare T-lymphocyte populations in peripheral blood, specifically double-positive T, natural killer T and activated T lymphocytes, as well as their relationship to sex and age. METHODS A cross-sectional study was carried out in 129 adults (68 women, 61 men) aged >18 years, without chronic diseases or unhealthy habits, who signed informed consent. Peripheral blood was collected for immunophenotyping of lymphocyte subpopulations with monoclonal antibodies specific for CD4+CD8+ double-positive T cells, CD3+CD56+ natural killer T cells, and CD3+CD25+HLA-DR+ activated T cells. An eight-color flow cytometer (Beckman Coulter Gallios) was used. The analytic strategy was modified, associating variables of interest in a single graphic, using conventional monoclonal labeling antibodies. Medians and minimum and maximum percentiles (2.5 and 97.5, respectively) were used as descriptive statistics, stratified by sex, for cell counts and percentages. A linear regression model was applied to assess age effects and a two-tailed Mann-Whitney U test for independent samples was used to assess sex differences. The significance threshold was set as p ≤0.05. RESULTS Median percentages of total lymphocytes: natural killer T cells 6.3% (1.4%–23%) in men and 4.7% (0.8%–11.3%) in women (p = 0.003); activated T cells 1.0% (0.2%–2.2%) in men and 1.2% (0.4%–3.1%) in women, without statistical significance; and double positives 0.8% (0.1%–4.2%) in men and 0.9% (0.3–5.1) in women, also without statistical significance. Median cell counts (cells/μL) were: natural killer T cells, 126 (27–580) in men and 105 (20–279) in women (p = 0.023); activated T cells: 20 (4–46) in men and 25 (7–75) in women, (p = 0.013) and double-positive T cells: 17 (2–85) in men and 21 (7–154) in women, without statistical significance. Sex influenced natural killer T cells, but age did not. CONCLUSIONS Age does not affect counts and percentages of rare T lymphocyte subpopulations in the blood of healthy Cuban adults. Sex differences found for some phenotypes suggest the need for different reference values for women and men.

ABSTRACT Introduction: The antinuclear antibody test is a powerful tool for diagnosing rheumatic diseases. Antinuclear antibodies are determined in the laboratory by an algorithm or sequence that starts with a screening test and continues with the identification of the most common antinuclear specificities. But how to interpret the discordant results between the two levels of study of antinuclear antibodies? Objective: To determine the less frequent antinuclear specificities in positive patients of ANA screening and negative of the most common specificities. Methods: A prospective study was done on 88 consecutive patients referred for the routine ANA screening with a positive result of screening by enzyme-linked immunosorbent assay (ELISA) but negative for anti-double-stranded DNA (dc, IgG) and common extractable anti-nuclear antigens (ENAc). The corresponding serum samples were evaluated by indirect immunofluorescence on human laryngeal epidermoid carcinoma cells (IFI-HEp-2) and by ELISA for the individual detection of specific ANA. Results: The ANA test by IFI / HEp-2 was positive in 56/88 (63.6 %) and the antinuclear specificities were detected in 57/88 (64.8 %) samples, in decreasing Anti-Nucs order: 16/88 (18.2 %); anti-centromere (CENP-B): 15/88 (17.0 %); -histona: 15/88 (17 %); -PM / Scl: 13/88 (14.8 %); -ADNsc: 11/88 (12.5 %) and -ENAc individual: 8/88 (9.1 %). The sensitivity of IFI-HEp-2 for antinuclear specificities was 0.83 (95 % CI: 0.72-0.93). No history of rheumatic disease associated with ANA was read in (26/31) 83.9 % patients with negative subserology. Conclusions: The majority of patients with discordant results between the first and second level of ANA were positive of less common antinuclear specificities, but of recognized diagnostic value.

RESUMEN Introducción: La prueba de anticuerpos antinucleares es una poderosa herramienta en el diagnóstico de las enfermedades reumáticas. Los anticuerpos antinucleares se determinan en el laboratorio por un algoritmo o secuencia que se inicia con prueba de cribado y sigue con la identificación de las especificidades antinucleares más comunes. Pero, ¿cómo interpretar los resultados discordantes entre los dos niveles de estudio de anticuerpos antinucleares? Objetivo: Determinar las especificidades antinucleares menos frecuentes en pacientes positivos de cribado de ANA y negativos de las especificidades más comunes. Métodos: Estudio prospectivo de 88 pacientes consecutivos remitidos para la detección rutinaria de ANA con resultado positivo de cribado por ensayo inmuno-adsorbente ligado a enzima (ELISA) pero negativo de anticuerpos anti-ADN de doble cadena (dc, IgG) y anti-antígenos nucleares extraíbles comunes (ENAc). Las muestras séricas correspondientes fueron evaluadas por inmunofluorescencia indirecta sobre células de carcinoma epidermoide laríngeo humano (IFI-HEp-2) y por ELISA para la detección individual de ANA específicos. Resultados: La prueba de ANA por IFI/HEp-2 resultó positiva en 56/88 (63,6 %) y las especificidades antinucleares se detectaron en 57/88 (64,8 %) muestras, en el orden decreciente de Anti-Nucs: 16/88 (18,2 %); anti-centrómero (CENP-B): 15/88 (17,0 %); -histona: 15/88 (17 %); -PM/Scl: 13/88 (14,8 %); -ADNsc: 11/88 (12,5 %) y -ENAc individuales: 8/88 (9,1 %). La sensibilidad de la IFI-HEp-2 para las especificidades antinucleares fue de 0,83 (IC95%: 0,72-0,93). De los pacientes negativos de subserología (26/31), 83,9 % no tenían antecedentes de enfermedad reumática asociada a ANA. Conclusiones: La mayoría de los pacientes con resultados discordantes entre el primer y segundo nivel de ANA fueron positivos de especificidades antinucleares menos comunes, pero de reconocido valor diagnóstico.

The acceptance and relevance of auto-antibodies is evidenced by their increasing incorporation into the diagnostic and classification criteria of autoimmune diseases. One of the current concerns arising from the widespread use of auto-antibodies is the observance of adequate use, as opposed to its undiscriminating use that results in an increase of false positive results leading to costly errors in diagnosis, follow-up, and even treatment of the patient. This article attempts to summarize the circumstances when it is timely to order autoantibody tests, and how to interpret them to preserve their clinical utility and control health expenditures.

La aceptación y la relevancia de los autoanticuerpos se evidencia por su creciente incorporación en los criterios diagnósticos y de clasificación de las enfermedades autoinmunes. Una de las preocupaciones actuales, derivadas del uso ampliado de los autoanticuerpos, es la conservación del uso adecuado, en contraposición con el uso indiscriminado que genera un aumento de resultados falsos positivos que conducen a costosos errores en el diagnóstico, seguimiento, e incluso, tratamiento del paciente. Este artículo intenta resumir las circunstancias en que es oportuno ordenar las pruebas de autoanticuerpos, y cómo interpretarlas para preservar su utilidad clínica y refrenar los gastos de salud.