Comparison of immunosuppressive therapies for IgA nephropathy after tonsillectomy: three-course versus one-course steroid pulse combined with mizoribine

PURPOSE: It has been reported that steroid pulse therapy for IgA nephropathy improves renal prognosis. However, because of the side effects, steroid dose must be restricted to some cases. Treatment effects of steroid on cases already presenting with reduced renal function are unknown. In this study, we performed tonsillectomy in patients with IgA nephropathy and conducted a comparative study about subsequent immunosuppressive therapy. METHODS: Subjects were patients younger than 70 years of age diagnosed with IgA nephropathy by renal biopsy. Treatment protocols were a single-course steroid pulse combined with mizoribine during a period from August 2006 to June 2010 (Group A; n = 34) and a three-course steroid pulse during a period from July 2010 to March 2013 (Group B; n = 32). Primary end points were excretory amounts of proteinuria, disappearance of proteinuria and hematuria, and exacerbation of renal function. RESULTS: In both the groups, proteinuria decreased significantly 12 months after treatment, and no significant difference in alleviation effects on proteinuria was found between groups. eGFR increased significantly 12 months after treatment in Group A, whereas it tended to decrease in Group B. As for the preservation effect on eGFR, Group A showed significantly higher preservation of eGFR. Similar results were shown in the patients whose eGFR at the start of the treatment was less than 60 mL/min/1.73 m(2). CONCLUSIONS: Single-course steroid pulse therapy combined with mizoribine was considered to have a protective effect on the renal function in IgA nephropathy, especially accompanying renal dysfunction.