Slide 1

Outcome of Kidney Transplants with Unrecognized Antibody Mediated Rejection

Ty Dunn, Y Kim, Abhi Humar, Raja Kandaswamy, David Sutherland, William Payne, and Arthur Matas
Department of Surgery, University of Minnesota, Minneapolis, MN

Body

Results

Prior to 2002, routine C4d staining was not done at our center. We retrospectively analyzed C4d deposition on biopsies done (and snap frozen) in this era. In doing so, we studied the outcomes of the grafts with unrecognized AMR and their response to standard therapy for cellular rejection.

% Acute Rejection Free

Patients & Methods

Between 1996 and 2001, 156 1st and 2nd kidney Txs underwent a clinically indicated graft biopsy in the 1st post-Tx year. Tissue was examined by light microscopy and simultaneously snap frozen and stored. Treatment for acute cellular rejection (ACR) was given as follows: mild ACR (1A) treated with steroid recycle, steroid resistant or moderate ACR (1B) with Thymoglobulin, and severe or vascular (>2) ACR with OKT3. Snap frozen tissue was retrospectively evaluated for C4d deposition. Recipient characteristics, treatments and outcomes were analyzed. Patients were grouped based on presence or absence of ACR and C4d.
Results: All 43 ACR- C4d- recipients were free from future ACR. 11 of 30 patients with ACR- C4d+ biopsies (37%) experienced a subsequent ACR (p=0.0001) by the end of the first post transplant year. 39 recipients were ACR+ C4d-, with 2 of these (5%) developing a 2nd ACR by the end of the first transplant year, compared to 6 of 35 (20%) ACR+ C4d+ recipients (p=0.09). Average followup was 8 years.

Years Post-Transplant

% Acute Rejection Free

Years Post-Transplant

Conclusion

Unrecognized C4d+ rejection is associated with an increased rate of subsequent ACR episodes. Evaluation of treatment response to lymphocyte depleting agents may provide insight to treatment effect on long-term graft survival rates in patients with early C4d+ rejection

UNIVERSITY OF MINNESOTA

MEDICAL CENTER

FAIRVIEW

© Department of Surgery, University of Minnesota

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