Clinical characteristics and prognosis analysis of children with idiopathic nephrotic syndrome with different responses to steroid therapy from a single center in 20 years

Abstract

Objective To analyze the clinical characteristics and prognosis of children diagnosed with idiopathic nephrotic syndrome that showed different responses to steroid treatment. Methods In this study, idiopathic nephrotic syndrome was defined as a 24-hour urinary protein of more than 50 mg/kg body weight as well as a serum albumin concentration of less than 25 g/L.A retrospective study was undertaken to analyze the children who were patients at Peking University First Hospital during Jan.1993 and Dec.2012 and conformed to the above criteria.According to their response to steroid therapy, the children were divided into 3 groups: group that demonstrated remission within 4 weeks after therapy, group that demonstrated remission within 4 to 8 weeks and group that demonstrated resistance to therapy after 8 weeks.Among the children who had more than 1 year of follow up, type of nephrotic syndrome(simple vs nephritic), complications, steroid side effects and serious prognosis(chronic renal failure, renal transplantation or death) were further analyzed. Results Out of total 1 059 children with idiopathic nephrotic syndrome, 841 cases had a documented steroid response and were analyzed.Among them, 71.7%(603/841 cases) showed remission within 4 weeks following steroid treatment, while 4.0%(34/841 cases) showed remission within 4 to 8 weeks and 24.3%(204/841 cases) showed no remission even after 8 weeks.The average remission time after steroid therapy was(13.2±8.9) d with a median of 10.0 d. Of these children, 369 cases had at least 1 year of follow up.In this subset, 74.8%(276/369 cases) went into remission within 4 weeks of steroid therapy, 4.9%(18/369 cases) showed remission within 4 to 8 weeks, and 20.3%(75/369 cases) were resistant to steroid therapy even after 8 weeks.Onset ages were significantly different(P<0.01) among the 3 groups [remission within 4 weeks: (5.2±3.3) years old; remission within 4 to 8 weeks: (5.7±3.3) years old; resistant to therapy after 8 weeks: (6.6±3.8) years old]. Simple type nephrotic syndrome was more common in children that responded to steroid therapy within 4 weeks(95.3%, 263/276 cases) and within 4 to 8 weeks(83.3%, 15/18 cases) than in children who were resistant to therapy after 8 weeks(45.3%, 34/75 cases). The occurrence rates of acute adrenocortical insufficiency showed a significant difference(P=0.04) among the 3 groups(remission within 4 weeks: 4.3%, 12/276 cases; remission within 4 to 8 weeks, 2/18 cases: 11.1%; resistant to therapy after 8 weeks: 0). The occurrence rates of poor prognosis were also significantly different(P<0.01) among the 3 groups(remission within 4 weeks: 1.4%, 4/276 cases; remission within 4 to 8 weeks: 0; resistant to therapy after 8 weeks: 16.0%, 12/75 cases). Conclusions Seventy-one point seven percent of children with idiopathic nephrotic syndrome responded to steroid therapy within 4 weeks.Among children that did not respond within 4 weeks following steroid therapy, 14.3% did respond within 8 weeks, while 85.7% showed no remission 8 weeks after therapy.The children who responded to steroid therapy within 8 weeks mainly presented as a simple type of nephrotic syndrome and had better prognosis, whereas the children that did not respond within 8 weeks mainly presented with nephritic type nephrotic syndrome and had a poorer prognosis.It should be noted that acute adrenocortical insufficiency was more likely to occur in children that responded to steroid therapy within 4 to 8 weeks. Key words: Nephrotic syndrome; Steroid response; Criteria; Child