Early posttransplant rituximab use in kidney transplant recipients with preexisting donor-specific antibodies

The presence of pretransplant anti-human leukocyte antigen (HLA) donor-specific antibodies (DSAs) is still a significant barrier to successful kidney transplantation, as it increases the risk of rejection and graft failure. Rituximab (anti-CD20 antibody) has been administered in hopes of suppressing DSA production and rejection in those with preformed DSAs. However, existing studies report conflicting outcomes, underscoring the need for more data to guide clinical practice. Thus, we evaluated the efficacy of early posttransplant rituximab administration in a cohort of kidney transplant recipients with pretransplant anti-HLA DSAs. In this retrospective study of 77 patients, we compared 1-year transplant outcomes between patients treated with and without rituximab for pretransplant anti-HLA DSAs. Infectious complications tended to occur more often in the rituximab group (BK polyomavirus DNAemia >10,000 copies/mL, 3 [19%] vs. 8 [13%]; quantifiable cytomegalovirus DNAemia, 8 [50%] vs. 19 [31%]; infection requiring hospitalization, 5 [31%] vs. 11 [18%]), but none of these differences reached statistical significance. The incidence of biopsy-proven rejection (2 [13%] vs. 12 [20%]) and high plasma donor-derived cell-free DNA (2 [18%] vs. 12 [27%]) tended to be more frequent in the no-rituximab group, but none of these reached statistical significance. Preexisting DSA persisted or recurred in 44% of the patients that received rituximab, and in 46% of patients who did not receive rituximab. Similarly, <i>de novo</i> DSA occurred in 31% of those who received rituximab versus in 25% of those who did not. Rituximab administration did not result difference in graft and patient survival or rejection rates or recurrence of preexisting DSA.