Proteinuria selectivity and prednisone response in children with nephrotic syndrome. / Selectividad de proteinuria y respuesta a prednisona en niños con síndrome nefrótico.

BACKGROUND: The proteinuria selectivity index (PSI) can predict the response to prednisone in the primary nephrotic syndrome (PNS). OBJECTIVE: To determine the association of prednisone response with the PSI in patients with PNS. MATERIAL AND METHODS: With analytical cross-sectional design, pediatric patients with PNS were studied with at least six months of prior follow-up, at the Nuevo Hospital Civil de Guadalajara from 2014 to 2015. They were divided into poor response to prednisone (frequent relapses or resistance) and good response (habitual relapses). PSI was calculated with serum and urinary measurement of IgG and transferrin. Chi square and OR were used, with 95% CI. RESULTS: 67 patients with relapsing PNS were studied. The response to prednisone had been good in 33 (49.3%) and poor in 34 (50.7%). The PSI was ≤ 0.10 mg/mg in 23/67 (34.3%); 0.11-0.19 mg/mg in 15/67 (22.4%); and ≥ 0.20 mg/mg 29/67 (43.3%). 3/34 patients (8.8%) presented ≤ 0.1 mg/mg with poor response to prednisone and 20/33 presented good response (60.6%) (p < 0.001; OR: 0.6; 95% CI, 0.010-20). PSI between 0.11-0-19 mg/mg occurred in 8/34 patients (23%) with poor response to prednisone and in 7/33 with good response (21%). PSI ≥ 0.20 mg/mg resulted in 23/34 patients (67.6%) with poor response to the steroid and in 6/33 with good response (18.2%) (p < 0.001; OR: 9.4; 95% CI, 3.01-29.42). CONCLUSIONS: In children with PNS, a PSI ≥ 0.20 mg/mg was associated with a poor response to prednisone treatment and a PSI ≤ 0.10 mg/mg with a satisfactory response.

INTRODUCCIÓN: El índice de selectividad de proteinuria (ISP) puede predecir la respuesta a prednisona en el síndrome nefrótico primario (SNP). OBJETIVO: Determinar la asociación de la respuesta a prednisona con el ISP en pacientes con SNP. MATERIAL Y MÉTODOS: Con diseño transversal analítico, se estudiaron pacientes pediátricos con SNP en recaída con al menos 6 meses de seguimiento previo, en el Nuevo Hospital Civil de Guadalajara, de 2014 a 2015. Se dividieron en mala respuesta a prednisona (recaídas frecuentes o resistencia) y buena respuesta (recaídas habituales). El ISP se calculó con medición sérica y urinaria de IgG y transferrina. Se utilizaron la prueba de chi cuadrada y razones de momios (RM) con sus intervalos de confianza del 95% (IC 95%). RESULTADOS: Se estudiaron 67 pacientes con SNP en recaída. La respuesta a prednisona había sido buena en 33 (49.3%) y mala en 34 (50.7%). De los 67 pacientes, el ISP fue ≤ 0.10 mg/mg en 23 (34.3%), 0.11-0.19 mg/mg en 15 (22.4%) y ≥ 0.20 mg/mg en 29 (43.3%). De los 34 con mala respuesta, el ISP fue ≤ 0.1 mg/mg en 3 (8.8%); de los 33 con buena respuesta, el ISP fue ≤ 0.1 mg/mg en 20 (60.6%) (p < 0.001; RM: 0.6; IC 95%: 0.010-20). El ISP fue 0.110-19 mg/mg en 8 (23%) de los 34 pacientes con mala respuesta a prednisona y en 7 (21%) de los 33 con buena respuesta. El ISP fue ≥ 0.20 mg/mg en 23 (67.6%) de los 34 pacientes con mala respuesta al esteroide y en 6 (18.2%) de los 33 con buena respuesta (p < 0.001; RM: 9.4; IC 95%: 3.01-29.42). CONCLUSIONES: En los niños con SNP, un ISP ≥ 0.20 mg/mg se asoció con mala respuesta a prednisona y un ISP ≤ 0.10 mg/mg se asoció con respuesta satisfactoria.

[Concordance of glomerular filtration rate with creatinine clearance in 24-hour urine and Schwartz and Schwartz updated]. / Concordancia de la tasa de filtración glomerular con depuración de creatinina en orina de 24 horas, fórmulas de Schwartz y Schwartz actualizada.

BACKGROUND: Reference methods for the quantification of the glomerular filtration rate (GFR) are difficult to use in clinical practice; formulas for evaluating GFR based on serum creatinine (SCr) and/or creatinine clearance are used. The aim of this study was to quantify the correlation and concordance of GFR with creatinine clearance in 24-hour urine (GFR24) and Schwartz and Schwartz updated formulas. METHODS: Cross-sectional study involving healthy pediatric patients and with chronic kidney disease (CKD) from 5 to 16.9 years. Linear correlation between GFR 24 and two formulas was evaluated with the Pearson correlation coefficient (r) and intraclass correlation coefficient (ICC). RESULTS: We studied 134 patients, of which 59.7% were male. Mean age was 10.8 years. The average GFR24 was 140.34ml/min/1.73m2; 34.3% (n=46) had GFR <90ml/min/1.73m2. Moderate linear correlation between GFR24 and Schwartz (r= 0.63) and Schwartz updated (r= 0.65) formulas was observed. There was good concordance between the GFR24 and Schwartz (ICC= 0.77) and updated Schwartz (ICC= 0.77) formulas. Schwartz classical formula in patients with GFR24 ≥ 90ml/min/1.73m2 estimated higher values, while Schwartz updated underestimated values. CONCLUSIONS: There is moderate correlation and good concordance between the GFR24 and Schwartz and Schwartz updated formulas. The concordance was better in patients with obesity and lower in women, patients with hyperfiltration and normal weight.

[Upper and lower neural tube defects: prevalence and association with illnesses and drugs]. / Defectos del tubo neural altos y bajos, prevalencia, y asociación con enfermedades y medicamentos.

OBJECTIVE: To determine the prevalence of upper and lower neural tube defects and identify its association with the exposure to illnesses and drugs during pregnancy. MATERIAL AND METHODS: This is a case-control study of 107 newborns with upper neural tube defects, 59 with lower neural tube defects, and 166 newborns without malformations, in 56,926 consecutive births between 1989 and 1997. The exposure was documented by a direct interview to the mother of those subject of study. The association was measured by the odds ratios, with confidence interval of 95%. RESULTS: The prevalence of upper neural tube defects was of 1.9 for 1,000 newborn (alive or dead) and of lower neural tube defects of 1.0 for 1,000. The exposure to illnesses of less than a month of duration was associated with upper neural tube defects (OR = 3.11; IC = 1.34-7.39) the most important was flu; also the exposure to drugs (OR = 5.85; IC = 2.97-11.62), the most prominent was acetaminophen. These factors of risk were not associated with lower neural tube defects. The mother's occupation, illness of more than a month of duration and X-ray exposure were not associated with of upper and lower neural tube defects. CONCLUSIONS: More studies are needed in the association among illnesses of less than a month of duration and drugs with upper neural tube defects. The different exposure frequencies between upper and lower neural tube defects suggest heterogeneity.

Concordancia de la tasa de filtración glomerular con depuración de creatinina en orina de 24 horas, fórmulas de Schwartz y Schwartz actualizada / Concordance of glomerular filtration rate with creatinine clearance in 24-hour urine and Schwartz and Schwartz updated

Resumen: Introducción: Los métodos de referencia para cuantificar la tasa de filtración glomerular (TFG) son poco accesibles en la práctica clínica. Para evaluar la TFG se utilizan fórmulas basadas en la creatinina sérica y/o aclaramiento de creatinina. El objetivo de este estudio fue cuantificar la correlación y concordancia de la TFG con depuración de creatinina en orina de 24 horas (TFG24) y fórmulas de Schwartz y Schwartz actualizada. Métodos: Estudio transversal analítico que incluyó pacientes de 5 a 16.9 años, sanos y con enfermedad renal crónica. Se evaluó la relación lineal entre la TFG24 y ambas fórmulas con el coeficiente de correlación de Pearson (r) y la concordancia con el coeficiente de correlación intraclase (CCI). Resultados: Se estudiaron 134 pacientes, 59.7% de género masculino, la edad promedio fue 10.8 años. La TFG24 promedio fue 140.34 ml/min/1.73 m2; el 34.3% (n = 46) presentaron TFG < 90 ml/min/1.73 m2. Se observó moderada relación lineal entre la TFG24 y las fórmulas de Schwartz (r= 0.63) y Schwartz actualizada (r= 0.65). Hubo buena concordancia entre la TFG24 y fórmula de Schwartz (CCI= 0.77) y de Schwartz actualizada (CCI= 0.77). En pacientes con TFG24 ≥ 90 ml/min/1.73 m2 la fórmula de Schwartz clásica estimó valores mayores de TFG, mientras que Schwartz actualizada subestimó los valores. Conclusiones: Existe moderada correlación y buena concordancia entre la TFG24 y fórmulas de Schwartz y Schwartz actualizada. Con ambas fórmulas la concordancia fue mayor en pacientes con obesidad y menor en mujeres, pacientes con hiperfiltración y con peso normal.

Abstract: Background: Reference methods for the quantification of the glomerular filtration rate (GFR) are difficult to use in clinical practice; formulas for evaluating GFR based on serum creatinine (SCr) and/or creatinine clearance are used. The aim of this study was to quantify the correlation and concordance of GFR with creatinine clearance in 24-hour urine (GFR24) and Schwartz and Schwartz updated formulas. Methods: Cross-sectional study involving healthy pediatric patients and with chronic kidney disease (CKD) from 5 to 16.9 years. Linear correlation between GFR 24 and two formulas was evaluated with the Pearson correlation coefficient (r) and intraclass correlation coefficient (ICC). Results: We studied 134 patients, of which 59.7% were male. Mean age was 10.8 years. The average GFR24 was 140.34 ml/min/1.73 m2; 34.3% (n = 46) had GFR <90 ml/min/1.73 m2. Moderate linear correlation between GFR24 and Schwartz (r= 0.63) and Schwartz updated (r= 0.65) formulas was observed. There was good concordance between the GFR24 and Schwartz (ICC= 0.77) and updated Schwartz (ICC= 0.77) formulas. Schwartz classical formula in patients with GFR24 ≥ 90 ml/min/1.73 m2 estimated higher values, while Schwartz updated underestimated values. Conclusions: There is moderate correlation and good concordance between the GFR24 and Schwartz and Schwartz updated formulas. The concordance was better in patients with obesity and lower in women, patients with hyperfiltration and normal weight.

Defectos del tubo neural altos y bajos, prevalencia, y asociación con enfermedades y medicamentos / Upper and lower neural tube defects: prevalence and association with illnesses and drugs

OBJECTIVE: To determine the prevalence of upper and lower neural tube defects and identify its association with the exposure to illnesses and drugs during pregnancy. MATERIAL AND METHODS: This is a case-control study of 107 newborns with upper neural tube defects, 59 with lower neural tube defects, and 166 newborns without malformations, in 56,926 consecutive births between 1989 and 1997. The exposure was documented by a direct interview to the mother of those subject of study. The association was measured by the odds ratios, with confidence interval of 95. RESULTS: The prevalence of upper neural tube defects was of 1.9 for 1,000 newborn (alive or dead) and of lower neural tube defects of 1.0 for 1,000. The exposure to illnesses of less than a month of duration was associated with upper neural tube defects (OR = 3.11; IC = 1.34-7.39) the most important was flu; also the exposure to drugs (OR = 5.85; IC = 2.97-11.62), the most prominent was acetaminophen. These factors of risk were not associated with lower neural tube defects. The mother's occupation, illness of more than a month of duration and X-ray exposure were not associated with of upper and lower neural tube defects. CONCLUSIONS: More studies are needed in the association among illnesses of less than a month of duration and drugs with upper neural tube defects. The different exposure frequencies between upper and lower neural tube defects suggest heterogeneity.