Renal Allograft Antibody Mediated Rejection in Highly Sensitized Patient

F.Q is a 49-year-old female with a history of end-stage renal disease secondary to unknown etiology. She was started on regular hemodialysis in 1996. Her other medical history included hypertension and chronic hepatitis C viral (HCV) infection (Grade 2 Stage 1). In January of 2000 she was cleared for receiving a living related kidney from her son with a one haplotype match. She had 0% cytotoxic antibodies (CTA). However, the crossmatch with her son was incompatible due to positive T-cell IgG by flow cytometry. Her B-cell IgG flow cytometry crossmatch was negative. Since the patient had no other available donor, she was waitlisted to receive a cadaver kidney. In April 2004, desensitization protocol was established at our institution and the couple was called for reassessment. The repetition of the initial crossmatch was this time compatible and the couple was cleared for the transplant surgery. The planned immunosup­pression was tacrolimus (FK506), myco­phenolate mofetil (MMF) and prednisone with anti CD 20 monoclonal antibody induction (basiliximab). However, when the final crossmatch was performed it proved to be again positive for T-cell both by flow cytometry (85 channel shift) and complement dependent cytotoxicity (CDC). The B-cell crossmatch remained negative and the CTA performed by the CDC method remained at 0%. No history of blood transfusion or other sensitizing events were detected between the different crossmatch procedures. The patient was deemed highly sensitized and the decision was made to proceed with the transplant­tation. Desensitization was performed with the administration of intravenous immunoglobulin (IVIG) 2 gm/kg over 36 hours, MMF one gm twice/day (bid) and rabbit anti-human thymocyte polyclonal antibody (ATG). The desensitization was successful as was evident by the conversion of the crossmatch to negative both by the flow cytometry and the CDC methods. The surgical procedure was uneventful.