Paternal leukocyte alloimmunization as a treatment for hemolytic disease of the newborn in a rabbit model

Objective: The purpose of this study was to evaluate maternal alloimmunization to paternal leukocytes as a treatment for hemolytic disease of the fetus/newborn in a rabbit model. Study Design: Twelve does and paired red blood cell-incompatible bucks underwent the experimental protocol. Fetal hematologic parameters that were obtained by ultrasound-guided intracardiac sampling were compared from unaffected, compatible litters; from affected, incompatible litters (after alloimmunization to red blood cell antigens); and from affected, incompatible litters after alloimmunization to paternal leukocytes. Generalized estimation equations were used for statistical analysis. A probability value of <.05 was considered significant. Results: Six of 12 does had at least one affected litter after alloimmunization to paternal leukocytes. After an adjustment for the mating cycle, the fetuses of does that underwent white blood cell immunization exhibited higher hemoglobin and hematocrit levels (β = 4.6, P< .001, and β = 11.6, P = .006, respectively) compared with the fetuses of does that were immunized only to red blood cells. Conclusion: Maternal alloimmunization to paternal leukocytes decreases the severity of hemolytic disease and may play a role in the treatment of severe hemolytic disease of the newborn in humans. (Am J Obstet Gynecol 2002;187:977-80.)