Aim: Desensitization with the intravenous immunoglobulin (IVIG) and Rituximab therapy is commonly used to promote transplant of highly sensitized patients. It is suggested that HLA-DQ antibodies are difficult to be desensitized compared to antibodies against other HLA loci. The aim of this study was to determine if the efficacy of the desensitization therapy is dependent on the specificities of HLA antibodies.

Methods: 20 sensitized patients treated with the IVIG/ Rituximab therapy from 01/01/2016- 12/31/2016 were evaluated. HLA antibodies were detected by single antigen testing on EDTA treated sera collected before and one month post therapy. Mean fluorescence intensity (MFI) of each bead in the single antigen testing panel was compared in the pre- and post-therapy samples. Because single antigen testing is saturated at MFI of ~15,000, we only included beads with MFI ≤15,000 in the analysis. 30% decrease of MFI was considered significantly different.

Results: Most antibodies were against HLA-A, B, followed by HLA-DR and DQ antibodies. There were less HLA -C and DP antibodies (Table 1). While the MFI of antibodies was significantly lower post therapy (p<0.001), only 28% of antibodies showed MFI reduction ≥30%. 24% of HLA-DQ antibodies had MFI reduction ≥30%, which was similar to HLA-B and HLA-C antibodies. HLA-DP and HLA-A appeared more susceptible to the therapy. We also found that efficacy of the therapy varied among subjects. Seven patients did not have MFI reduction at all after the therapy, while more than 50% antibodies were reduced in 2 patients. Decrease on MFI was not associated with previous transplants or gender.

Conclusion: HLA-DQ antibodies underwent similar reductions seen with other HLA class I/class II antibodies. Of interest is the significant variations in reductive capacity of desensitization on MFI from patient to patient.

CITATION INFORMATION: Zhang X., Jordan S. Efficacy of IVIG + Rituximab Desensitization Therapy on HLA Antibodies is Independent of HLA Loci Am J Transplant. 2017;17 (suppl 3).

« Back to 2018 American Transplant Congress