5.166667
#177
ANTI-HLA-DP ANTIBODIES MAY REPRESENT A SIGNIFICANT BARRIER TO SUCCESSFUL KIDNEY TRANSPLANTATION IN RE-GRAFTED PATIENTS.
Malek Kamoun 1, Marty Sellers 2, Christa Whitney-Miller 1, Jane Kearns 1, Erin Pierce 1, John Tomaszewski 1, Alden Doyle 3, Robert Grossman 3, Roy Bloom 3, Ali Naji 2, James Markmann 2 and Simin Goral 3. 1 Pathology and Lab Med, University of Pennsylvania, Philadelphia, PA, USA ; 2 Surgery and 3 Medicine .
The clinical significance of anti-HLA-DP Abs in renal transplantation is unclear. We report a case of recurrent acute humoral graft rejections that appears to be due to pre-formed anti-HLA-DP Abs. The patient is a non-transfused, 1-parous female who received her 1st transplant (3 A, B, DR mismatches) in 1986 and a 2nd transplant (1 DQ mismatch) in 1996 from a deceased kidney donor (DKD). Later, she developed Abs to mismatched donor class I and class II antigens from her 1st and 2nd transplant (PRA: 40% to 80%); anti-HLA-DP Abs were also detected with Flow PRA Single Antigen Bead assay. In Feb. 2005, she received a 3rd transplant from a zero A, B, C, DR, DQ mismatched DKD. The flow cytometry crossmatch was negative with T cells but positive with B cells, which was not due to autoAb. Further typing revealed two HLA-DPB1 mismatches. These findings indicated that the reactivity in the B cell crossmatch was most likely due to the anti-HLA-DP Abs. The patient received induction with 4 doses of Thymoglobulin and started on tacrolimus, mycophenolate mofetil, and prednisone and was discharged home with a serum creatinine (Cr) of 1.7 mg/dl. Within 2 weeks after the transplant, she experienced acute humoral and cellular rejection which recurred and has partially responded to a combination of plasmapheresis, Thymoglobulin and Rituximab. Her Cr is 3.0 mg/dl 2.5 months after the transplant.
This case suggests that pre-sensitization to HLA-DP may represent a significant barrier to successful kidney transplantation in re-grafted recipients.