Therapeutic Effects and Prognostic Factors in Tonsillectomy Patients with IgA Nephropathy

Introduction : Because upper respiratory tract infections, particularly tonsillitis, often precede IgA nephropathy (IgAN), IgAN is now recognized as a tonsil-related disease, and reports have shown that tonsillectomy is effective in preventing disease progression in IgAN patients. IgA may thus play an important role in IgAN pathogenesis and development. B cell activation factor belonging to the TNF family (BAFF) is expressed by monocytes, macrophages, and dendritic cells, and may be the mechanism by which macrophages and dendritic cells directly regulate human B-cell activation. BAFF acts as a potent B-cell growth factor and costimulator of immunoglobulin production, including IgA. We studied therapeutic effects and serum BAFF levels as prognostic factors. Patients and Methods : Subjects were 41 patients undergoing tonsillectomy and followed up for at least 1 year. Serum samples were obtained from 38 with IgAN and 29 with recurrent tonsillitis as a properative control groups. The remission group consisted of patients with normal renal function without hematuria and proteinuria. Serum BAFF levels were measured by ELISA kits at our laboratory. Results : Overall remission was 39.0%. The disappearance of hematuria increased for long-term follow-up groups, but proteinuria was unchanged. Serum BAFF levels among the two groups did not differ significantly. Among IgAN patients, higher BAFF levels were associated with higher serum IgA/C3 levels. The correlation was weak (p=0.026, r=0.407). Using 3.2 ng/ml as a cut off point, we compared cumulative improvement in those with high pretreatment BAFF levels to those with low pretreatment levels. Those with high pretreatment BAFF levels had inferior cumulative improvement in hematuria. Conclusion : Tonsillectomy was effective in improving hematuria. BAFF appears to be a key factor in tonsillectomy among IgAN patients.