[Therapeutic effects and prognostic factors of tonsillectomy for IgA nephropathy in long-term follow-up].

I investigated several factors that can predict the effect of tonsillectomy for the prevention of renal failure in IgA nephropathy patients. Samples were obtained from 71 patients (35 male and 36 female) who were diagnosed as having IgA nephropathy by renal biopsy and the patients were followed-up for more than 5 years. Mean age at the time of renal biopsy was 28.3 years (8-58 years), and the mean follow-up period was 9 years 9 months (5-19 years). The overall remission rate of IgA nephropathy after tonsillectomy was 28.2%, and the retention rate of renal function was 90.1%, showing a considerably better prognosis than alternative therapies previously reported. Statistical analysis of multiple prognostic factors were examined including the following: sex, age-at-biopsy, renal pathological findings, renal function, serum IgA level, hypertension, past history of tonsillitis, preoperative results of tonsillar provocation test, and the period from diagnosis to tonsillectomy. A statistically significant poorer prognosis after tonsillectomy was observed in the following conditions: < or = 20-years-old when diagnosed, serum creatinine level > or = 1.3 mg/dl, urinary protein > or = 1.0 g/day, serum IgA level > or = 350 mg/dl. No other factors affected the prognosis of renal function statistically, including past history of tonsillitis or positive result of tonsillar provocation test. The present study indicates that there is a beneficial effect of tonsillectomy for mild to moderate IgA nephropathy and that this operation may be indicated for IgA nephropathy as long as the pathological grading is not advanced. On the other hand, tonsillectomy was not effective in cases with poor renal function. Although a past history of tonsillitis and positive results in tonsillar provocation tests have been widely considered as good indicators of tonsillectomy for IgA nephropathy, the present study showed no benefit to consideration of these factors preoperatively.