Abstract: SA-PO524

Fate of Mesangial IgA Deposits in Donated Kidney after Transplantation

Session Information

Category: Transplantation

  • 1702 Transplantation: Clinical and Translational

Author

  • Khan, Faiza N., None, Sugar Land, Texas, United States
Background

IgA nephropathy is a primary cause of glomerulonephritis in the world with a recognized progression to ESRD and a known recurrence in transplanted kidney. However, the clinical significance of mesangial IgA deposits in healthy individuals and donor kidneys is unclear. Although, IgA deposits are often considered to be a precursor lesion to IgA nephropathy, the two entities likely have a distinct pathogenesis. Whereas IgA nephropathy results because of an aberrant IgA protein which activates the immune system causing mesangial damage, mesangial IgA deposits result from a high circulating load of normal IgA protein which deposit in mesangium due to filtration. Prior studies regarding mesangial IgA arise from eastern hemisphere where IgA nephropathy is common. We examined the frequency, clinical significance and histological fate of mesangial IgA deposits in our heterogenous population.

Methods

Donor baseline biopsies obtained at Houston Methodist Hospital during 2009-2016 were examined for IgA deposits noted with immunofluorescence. Subsequent biopsies of recipients of IgA positive deposits were examined for outcome of these deposits. Clinical data was obtained and two tailed T test was used to compare categorical variables.

Results

958 baseline biopsies were examined. 94 biopsies had positive IgA deposits as the dominant or co-dominant immunoglobulin. An overall incidence rate of mesangial IgA deposits of 9.8% was noted with an incidence rate of 12.2% in deceased donor population and a rate of 6.3% in living donors. Of the 94 positive baseline biopsies, 43 recipients had adequate subsequent biopsies. During the first post-transplant year, 65% of the recipients showed complete resolution of IgA deposits and 12% with decreased IgA deposits. Mean time to resolution of IgA deposits in all re-biopsies was noted to be 295 days. Kaplan- Meier analysis (KM)of patient survival at 5 years showed 90% patient survival in IgA positive recipients vs 88% in recipients without IgA deposits. KM analaysis of graft survival at 5 years showed 88% graft survival in IgA positive donors vs 80% in donors without IgA deposits.

Conclusion

A higher incidence of mesangial IgA deposits were noted in deceased donors than living donors which may be secondary to systemic illnesses present in our deceased donors. Donor kidneys with IgA deposits have a higher incidence of delayed graft function but similar rate of patient and graft survival.