Serological and genetic factors in early recurrence of IgA nephropathy after renal transplantation

Background: The relative role of IgA anomalies and genetic factors in IgA nephropathy (IgAN) recurrence after transplantation has never been investigated in a single cohort. Methods: Sixty-one transplanted patients who had IgAN as an original disease (30 with biopsy-proved early recurrence, median 2.9 yr post-transplant), and 120 controls, were investigated for aberrantly glycosylated IgA1, IgA binding to mesangial matrix, macromolecular IgA (IgA/fibronectin and uteroglobulin/IgA/fibronectin complexes), and polymorphisms of cytokines [tumor necrosis factor alpha (TNFα), interleukin 10 (IL-10), IL-6, interferon gamma and transforming growth factor beta 1] and renin-angiotensin system (angiotensinogen converting enzyme, angiotensin II receptor 1, and angiotensinogen) genes. Results: At multivariate logistic regression analysis, recurrence showed a border-line association with aberrantly glycosylated IgA1 [odds ratio (OR) 8.172, p = 0.077], and was significantly less frequent in carriers of -308 AG/AA TNF-α“high producer” genotype (OR 0.125, p = 0.036) and -1082, -819, -592 ACC/ATA IL-10 “low producer” (OR 0.038, p = 0.009) genotypes. Conclusion: High levels of aberrantly glycosylated IgA1 do not appear to play a strong crucial role in recurrence of IgAN. Polymorphisms of TNFα and IL-10 known to condition Th1 prevalence were associated with protection from early recurrence of IgAN.