Isoagglutinin Titers in ABO-Incompatible Kidney Transplant.

Background: A decrease in the isoagglutinin titer <1:8 is usually required for ABO-incompatible (ABOi) transplantation and the presence of high predesensitization titers may condition future transplantation. The aim of the study was to analyze the prognosis of ABOi patients undergoing desensitization and to compare the results according to the baseline isoagglutinin titer.

Methods: ABOi patients transplanted in our center after desensitization with rituximab, apheresis (plasmapheresis, immunoadsorption with Glycosorb, or both) and immunoglobulins were studied. Survival, renal function, and complications were analyzed and the results were compared according to the presence of a baseline isoagglutinin titer higher or lower than 1:128. We analyzed 48 patients (34 male) with a mean age of 50.9 ± 11 years and a mean follow-up of 44.6 ± 30 months. Thirty-eight patients had a basal isoagglutinin titer ≤1:128 and 10 had a titer >1:128. We did not observe differences in patient survival: 96% vs 100% at 5 years (P = .64) and renal survival: 91% vs 100% at 5 years (P = .39), incidence of acute rejection: 13.2% vs 0% (P = .22), infectious complications (cytomegalovirus; 16% vs 30%, P = 0.30; Polyomavirus BK virus: 13% vs 0%, P  =  .22), or surgical (hematoma): 47% vs 60% (P = .47) between the 2 groups. A higher number of apheresis sessions was observed (4.8 ± 1.9 vs 10.9 ± 3.9; P = .001); use of both techniques (0% vs 100%, P < .001) and higher processed volume (1 ± 0.1 vs 1.4 ± 0.5; P = .049) in patients with titer >128 was observed. Creatinine and proteinuria were similar and not significant.

Conclusions: Baseline isoagglutinin titer does not influence the prognosis of ABOi patients after desensitization. The number of sessions required to achieve baseline titer <1:8 is higher but does not influence the number of days of hospital admission.