Introduction: B-cell activating factor, belonging to the tumor necrosis factor (TNF) superfamily (BAFF), plays an important role in the development and survival of B lymphocytes. The present study was to investigate the correlation of BAFF and complement residue C4d in kidney allograft biopsies.
Methods: Transplant kidney biopsies as allograft were studied. 10 acute rejection (AR) cases, 3 interstitial fibrosis/tubular atrophy (IF/TA) cases, and 9 unknown etiology cases from January 1, 2001 to July 20, 2007 were analyzed. Transplanted kidneys were excised because of graft loss, and their pathological sections were studied. Ten other protocol biopsy specimens were studied. These recipients who received protocol biopsies had serum creatinine levels that were within normal range (normal value: < 144 micromol/L) from 2007. [corrected] BAFF, C4d, and immunoglobulin G (IgG) were detected by immunohistochemical stain methods. All were primary renal transplant recipients.
Results: In AR and IF/TA cases, BAFF was strongly stained, similar to C4d. And BAFF and C4d were distributed in the perinephric tubular epithelial cell cytoplasm and cytomembrane. In the unknown etiology sections and protocol biopsy sections, BAFF was weakly or not expressed, similar to C4d. In BAFF and C4d high expression sections, weak or moderate IgG deposition was also found.
Conclusion: BAFF may be associated with the development of antibody-mediated allograft rejection in kidney transplantation.