Association Between Post-transplantation Immunoglobulin A Deposition and Reduced Allograft Function

•Post-transplant IgA deposition was first observed 1 year after transplantation.•Of the 45 recipients, 18 had post-transplant IgA deposition in the allograft.•Urinalysis was normal in 61% of recipients with IgA deposition.•Reduced allograft function was associated with post-transplant IgA deposition.•Mycophenolic acid blood concentration was not associated with IgA deposition.

BackgroundPost-transplantation de novo and recurrent immunoglobulin A (IgA) deposition (IgAD) in the allograft is commonly observed. However, the association between post-transplantation IgAD and reduced allograft function has not been determined. We therefore investigated the association between reduced allograft function and post-transplantation IgAD using serial allograft biopsies.MethodsIgAD was retrospectively analyzed in 45 adults who underwent kidney transplantation for chronic glomerulonephritis, including IgA nephropathy, at Kagawa University Hospital. Allograft biopsy samples were obtained from per protocol biopsies obtained 1 and 3 years after transplantation, as well as from episode biopsies. Factors contributing to post-transplantation IgAD were assessed by calculating adjusted odds ratios (AORs) using logistic regression analysis.ResultsOf the 45 recipients, 18 had post-transplantation allograft IgAD. The estimated glomerular filtration rates (eGFR) 1, 2, and 3 years after transplantation were lower in the recipients with than without IgAD. Urinalysis was normal in 61% of recipients with IgAD. Reduced allograft function (eGFR <40 mL/min/1.73 m2) 1 year after transplantation was significantly associated with post-transplantation IgAD (AOR = 34.4 [95% CI = 2.35–502], P = .01). Conversely, blood concentrations of mycophenolic acid and latent IgAD from donor kidneys were not significantly associated with post-transplantation IgAD.ConclusionReduced allograft function may be associated with post-transplantation IgAD in the allograft.