Allo-sensitization profile in renal transplant patients with systemic lupus erythematosus

Abstract

Aim Systemic lupus erytematosus (SLE) is the autoimmune disease with the highest prevalence in renal transplant population. The purpose of the present study was to describe the sensitization profile in renal transplant patients with end stage renal disease due to SLE. Methods A retrospective single-center analysis in the last ten years revealed 26 all renal transplant patients with SLE - twenty females and six males. This group was matched to a 53 patient control group, with no SLE, but matched for gender and age distribution. The HLA polymorphism for -A, -B, -C, -DRB1, -DRB3/4/5, -DQB1, -DQA1, -DPB1 was performed by reverse SSO for intermediate resolution in all patients, while high resolution SBT (Sanger) was used for 12 cases. The auto-crossmatches were performed both by complement-dependent cytotoxicity, and by flowcytometry. The presence and identification of anti-HLA antibody was achieved by single-antigen bead (Luminex) assays. Results The HLA typing in SLE group has shown a higher (19/26, 73%) prevalence of HLA-DRB1–3/4/5 antigens when compared to control group (8/53, 15%, p 0.05). Furthermore, 4 SLE patients (15%) exhibited a positive cytotoxic and flow auto-crossmatch, compared to only 1 (2%) in controls (p 0.01). The distribution of HLA-specific antibody was 20/26 (77%) in SLE versus 18/53 in controls (33%), p 0.01 The class distribution in SLE group was: 19 anti-class I, and 11 anti class II, versus 11 class I and 7 class II in controls. 22 patients in SLE group exhibited anti-HLA antibody towards public epitopes resulting in a calculated PRA > 50%, while 19 SLE patients exhibited anti-HLA antibody towards public epitopes resulting in a calculated PRA > 80%. The control group had a significantly lower proportion of strong antibody towards public epitopes (4/18 and 2/18, respectively, p 0.01). Conclusions Renal transplant patients with SLE exhibited a higher prevalence of HLA-DRB1-3/4/5 self antigens, and a higher prevalence of positive auto-crossmatches and strong HLA antibody towards public epitopes.