Triggers of relapse in steroid-dependent and frequently relapsing nephrotic syndrome

An awareness of the triggers of relapse is critical for the control of steroid-dependent, frequently relapsing nephrotic syndrome (SDFRNS). We have investigated the triggers, usually described as 'episodes', to such relapses within a temporal context. Thirty-five patients with SDFRNS were analyzed retrospectively. A total of 442 relapses occurred in 2499 patient-months. The relapses were classified into two groups: those with episodes (E+) and those without episodes (E-). There were 135 E+ relapses and 296 E- relapses. The common cold was the most common episode (52%) of E+ relapse, followed by school events (18%). These E+ relapses occurred almost evenly throughout the 4 weeks between each follow-up visit. Conversely, 161 (55%) of the 296 E-z relapses occurred within the 3-day period preceding the patient's appointment (relapse-related hospital visit, RRHV). McNemar's test revealed that the concentration of relapses in this period was statistically significant (P < 0.00011). In addition, 15 out of 26 RRHV without additional therapy showed a spontaneous remission. From a chronological perspective, the common cold and school events as well as up-coming hospital visits may trigger relapses in SDFRNS patients.