Leukoreduction and ultraviolet treatment reduce both the magnitude and the duration of the HLA antibody response

Abstract

Background: Both leukoreduction and ultraviolet (UV) light treatment of blood products have been shown to reduce the incidence of HLA antibody development in recipients, but the impact of these treatments on the magnitude and persistence of the antibody response is less clear.

Study design and methods: Longitudinal samples from 319 subjects taken from four different study cohorts were evaluated for HLA antibodies to determine the effects of leukoreduction and UV treatment on HLA antibody generation and persistence.

Results: Subjects receiving leukoreduced or UV-treated blood products were less likely to generate Class I HLA antibodies, and those receiving leukoreduced blood were also less likely to generate Class II HLA antibodies. Among those receiving nonleukoreduced blood, 55% developed Class I HLA antibodies and 51% developed Class II HLA antibodies compared with 28% (Class I) and 15% (Class II) for those receiving leukoreduced blood and 36% (Class I) and 54% (Class II) for those receiving UV-treated blood. Among alloimmunized subjects, leukoreduction resulted in a significant twofold reduction in the magnitude of Class I HLA antibodies, and UV treatment resulted in a significant threefold reduction in the magnitude of Class II HLA antibodies. Both treatments resulted in shorter persistence of Class I HLA antibodies.

Conclusions: These data demonstrate that leukoreduction and UV treatment of blood products results not only in a reduction in the incidence of HLA antibody production, but also in lower and more transient HLA antibody levels among sensitized transfusion recipients.

Figure 1. Mean anti-HLA antibody NBG ratios are higher in recipients of non-leukoreduced blood

Peak class I (A) and class II (B) HLA antibody NBG ratios were compared among recipients of non-leukoreduced (Non-LR), leukoreduced (LR), and UV-treated (UV) blood products, as well as with non-transfused surgical and trauma patients (No Tx). Mean values were compared using a one-way ANOVA with Tukey’s multiple comparison post-test, *p<0.05, **p<0.01, ***p<0.001. Dashed line used to mark the NBG cutoff used to distinguish positive and negative results. Error bars display mean and standard error.

Figure 2. Mean HLA antibody NBG ratios are higher among responders in recipients of non-leukoreduced blood

Peak class I (A) and class II (B) HLA antibody NBG ratios were compared among recipients who developed new antibodies following transfusions with non-leukoreduced (Non-LR), leukoreduced (LR), or UV-treated (UV) blood. Mean values were compared using a one-way ANOVA with Tukey’s multiple comparison post-test, *p<0.05. Dashed line used to mark the cutoff used to distinguish positive and negative results. Error bars display mean and standard error.

Figure 3. Class I HLA antibodies persist slightly longer in recipients of non-leukoreduced blood

Longitudinal class I and class II HLA antibody NBG ratios were evaluated over time for recipients of non-leukoreduced (Non-LR), leukoreduced (LR), and UV-treated blood products. Kaplan-Meier survival analysis was used to evaluate the persistence of new class I (A) and class II (B) antibodies, with recipients of leukoreduced and UV-treated blood products compared with recipients of non-leukoreduced blood products using the log-rank test with associated p-values reported for each group compared with recipients of non-leukoreduced blood.