Nephrotic Syndrome in Thai Children: Nakornping Hospital Experience

Abstract

Objective: The purposes of this study are to determine the incidence, age of onset, gender, initial presentations, predictive parameters of frequent relapsers/steroid dependence and steroid resistance, results of disease course, growth retardation and complications of long term prednisolone therapy.
Methods: A retrospective descriptive study was done in 37 pediatric patients with their first episode of primary nephrotic syndrome admitted at Nakornping Hospital during 1 October 2002 to 30 September 2005. The data in medical records were analyzed by using descriptive statistics. This study used percentage, mean, median and standard deviation for basic data. Statistical analyses were done by Student’s t - test, Fisher’s exact test and Chi-square test for testing of statistically significant differences.
Results: The average age of patients was 7.7 years (male 7.7 years, female 7.7 years). The estimated annual incidence of nephrotic syndrome in healthy children in Chiang Mai was at least 3.48 new cases per 100,000 children younger than 15 years of age with the average of treatment period 19.2 months (2-36 months). Initial presentations consisted of generalized edema (86.4%), renal insufficiency (48.6%), fever (37.8%), hypertension (32.4%), gross hematuria (21.65%), and microscopic hematuria (21.6%). Initial therapy consisted of 60 mg/m2/day prednisolone daily for 4 weeks followed by 40 mg/m2 on alternate days for 4 weeks, thereafter decreasing alternate-day therapy every month by 25% over the next 4 months. Thirty-one patients (83.8%) were steroid-responsive, 6 patients (16.2%) were steroid-resistant. Of the 31 initial responders, 4 patients were excluded because of short follow-up period. Of the remaining 27 patients, 16 patients (59.2%) were nonrelapsers, 4 patients (14.85%) were infrequent relapsers, 6 patients (22.2%) were frequent relapsers/steroid dependence and one (3.7%) subsequently became steroid-resistant. The average of initial remission time (protein-free urine) was 16.4 days (15.2 days in nonrelapsers and infrequent relapsers, 21 days in frequent relapsers/steroid-dependent patients). The study for predictive parameters predicting the response of steroid therapy found that a group of the frequent relapsers/steroid-dependent and steroid-resistant patients had ascites, pulmonary edema/plural effusion, moderate renal insufficiency (GFR <60 ml/min/1.73m2), and gross hematuria more frequent than a group of the nonrelapsers and infrequent relapsers. But mild renal insufficiency (GFR 60-89 ml/min/1.73m2) was found less than the latter group. Only moderate renal insufficiency was statistically different in both groups. Six frequent relapsers/steroid-dependent patients had average occurrence of 2.83 relapses. All had complete remission. Three patients who used cyclophosphamide had longer complete remission than nonuser group (17 months versus 3.6 months). Seven steroidresistant patients were treated with cyclophosphamide, 2 patients (28.56%) had complete remission for 25 months, the other two patients had complete remission for 1.5 and 3 months, respectively. Three patients were still depended on steroid. BMI and height for age in all patients were normal except one patient with BMI> 25.
Conclusion: The increasing average age of first diagnosis of primary NS may indicate that there are more frequent relapsers/ steroid-dependent and steroid-resistant patients than the past. The frequent initial presentations are generalized edema, renal insufficiency, hematuria, fever, and hypertension. The initial parameters that can predict the frequent relapsers/steroid dependence and steroid resistance are moderate renal insufficiency, gross hematuria, pulmonary edema/pleural effusion, and ascites. The frequent relapsers/steroid dependence and steroid resistance had more severe degree of renal insufficiency. The longer duration of treatment until the patientus urine became protein-free may be a predictor of frequent relapsers/steroid dependence. The long regimen of steroid therapy for the initial episode may result in sustained complete remission and reduce frequency of relapses with few complications and growth retardation. The treatment of frequent relapsers/steroid dependence with cyclophosphamide may result in longer complete remission. Failure of cyclophosphamide therapy in steroid resistance indicates a consideration of other drugs. Therefore, this study indicates the benefits of completed information collection which may improve the outcome of treatment and encourage the physicians to study further for more completed outcomes.