Comparison between consecutive and intermittent steroid pulse therapy combined with tonsillectomy for clinical remission of IgA nephropathy.

Background: In recent years, tonsillectomy and steroid pulse (TSP) therapy have been widely performed in Japan. However, there is no consensus about the treatment protocol and indication.
Methods: In this retrospective analysis, we compared patients who received tonsillectomy plus intermittent steroid pulse (SP) therapy three times in 6 months (ISP group, n = 44) with patients who received tonsillectomy plus 3 weeks of consecutive SP therapy (CSP group, n = 46) within 1 year after renal biopsy. These two different protocols were performed at two different institutions. We analyzed the clinical and histological background and clinical remission (CR), defined as disappearance of urine abnormalities at 18 months after starting treatment.
Results: Before treatment, there was no significant difference in the clinical findings except for sex between the two groups. In ISP group and CSP group, mean estimated glomerular filtration rate was 82.1 ± 20.9 and 85.9 ± 19.1 ml/min/1.73 m(2), median proteinuria was 0.55 and 0.56 g/day, and median urinary red blood cells were 20 (10-20) and 20 (6-30)/high power filed. The histological (H) grade was lower in the CSP than the ISP group (p = 0.022). The remission rate of proteinuria, hematuria, and rate of CR by the Kaplan-Meier method and logrank test were significantly higher in the CSP group than in the ISP group (CSP vs. ISP group; proteinuria: 97.8 vs. 77.3 %, p < 0.001, hematuria: 97.8 vs. 75.0 %, p = 0.005, CR: 95.6 vs. 63.6 %, p < 0.001). In the Cox proportional hazard model (forced entry), SP protocol and proteinuria before treatment were significantly associated with CR [SP protocol: hazard ratio (HR) 2.50, 95 % confidence interval (CI) 1.46-4.30, p = 0.001, proteinuria: HR 0.81, 95 % CI 0.68-0.96, p = 0.013)]. However H-grade was associated with remission of proteinuria (H-grade: hazard ratio (HR) 0.56, 95 % confidence interval (CI) 0.37-0.85, p = 0.006), and this result meant histological bias affected the remission of proteinuria.
Conclusions: The difference of the protocol of TSP therapy may have some effect on the CR of IgAN, though the histological bias was observed in this study. The appropriate protocol and indication of TSP therapy must be analyzed and determined in the randomized controlled trial.