Atopy, Eosinophilia, Complete Blood Count (CBC) and the Risk of Rejection in Pediatric Heart Transplant Recipients

Abstract

Purpose Further understanding of risk factors for rejection can allow clinicians to reduce immunosuppression. CD3 lymphocytes play a central role in adaptive immune function with the Th1 phenotype (pro-inflammatory) being a mediator and the Th2 (pro-atopic)possibly being suppressive of rejection. Children have less rejection and more atopic conditions compared to adults. Therefore, we ask whether an association exists between the atopic state and freedom from rejection. Methods and Materials Single-center, observational study of recipients transplanted before 21yrs of age with ≥12 mos FU. Pre-specified biannual CBCs plus clinical information were collected. Individual patient CBC values were grouped and then further combined for comparative analyses. Rejection is defined by need for rescue therapy. Results Study period was 1994-2011 and 86 patients qualified. Median age at transplant was 14.5 mos with mean FU of 40.5 mos and 6.8 CBCs/patient. Atopic conditions necessitating intervention were common (56% of patients) and was associated with age at transplant 3 , p=0.068 ) approached significance with AMR. Conclusions This is the first study to suggest an association between low eosinophil count and rejection. Eosinophilia may be a useful marker of low rejection risk. Future studies will examine its clinical relationship to Th1/Th2 phenotype balance.