Platelet transfusions are associated with the development of anti-major histocompatibility complex class I antibodies in patients with left ventricular assist support

Preformed anti-human leukocyte antigen (HLA) antibodies delay heart transplantation in patients with left ventricular assist devices (LVAD) because of difficulty in finding crossmatch-negative donors. These antibodies may also be associated with adverse outcome after transplantation.

In a retrospective analysis of 40 patients with LVAD at Columbia-Presbyterian Medical Center between 1990 to 1996, age, sex, diagnosis, race, duration of support, transfusions, and infections were studied by univariate and multivariate analysis as predictors for development of either anti-HLA class I (anti-I) or anti-HLA class II (anti-II) immunoglobulin G (IgG) or M (IgM) antibodies.

Eighteen (45%) patients had development of anti-I and 20 (50%) had development of anti-II antibodies over the study period. Median time for LVAD support was 142 days (range 35 to 439). Only total number of perioperative platelet transfusions predicted the development of anti-I IgG antibodies (p = .04). No other associations were found for development of anti-I IgM or anti-II antibodies of either IgG or IgM specificity. Patients who had development of anti-I IgG received a mean of 13.9 (SE +/- 2.6) units of platelets compared with a mean of 7.7 (SE +/- 2.3) units in those who did not (p = .01). By Kaplan-Meier analysis, at the median duration of follow-up, 8% of patients receiving < 6 units were predicted to have development of anti-I antibodies compared with 63% receiving > 6 units (p = .002). In the last 7 patients, leukocyte filters were used to decrease the antigenic load during platelet and red blood cell transfusions. Only 1 of 7 (14%) patients had development of anti-HLA antibodies compared with 31 of 33 (94%) in whom filters were not used (p < .005).

These results indicate that platelet transfusion during LVAD implantation is a risk factor associated with development of HLA class I IgG antibodies. Use of leukocyte filters during platelet transfusion may decrease the risk of development of anti-HLA antibodies.