Survey of Platelet Glycoprotein Specific Antibodies and HLA Class I Antibodies in Hemodialysis Patients

Abstract

Renal transplant recipients who are sensitized to Major Histocompatibility Complex (MHC) antigens have more difficulties identifying HLA matched donors, who are also cross-match negative; therefore, the medical costs of transplant rejection treatment after transplantation are significantly more expensive. This study is designed to investigate the prevalence of Human Leukocyte Antigen (HLA) Class Ⅰ and platelet glycoprotein specific antibodies in patients who have received transfusions and are undergoing hospital based hemodialysis. There are several factors related to increased sensitization of this patient group, including gender, age difference and pregnancy, all of which were evaluated in this study. Forty-seven serum samples were collected from hemodialysis patients between March and May in the year 2007. All patients' sera were tested for presence of HLA Class I and platelet glycoprotein specific antibodies by an US-FDA licensed commercial ELISA kit. The polymorphic epitopes of platelet specific antigens include GPⅡb/Ⅲa (HPA-1a/1a, HPA-3a/3a, HPA-4a), GPⅡb/Ⅲa (HPA-1b/1b, HPA-3b/3b, HPA-4a), GPⅠa/Ⅱa (HPA-5b/ 5b), GPⅠa/Ⅱa (HPA-5a/5a), GPⅠb/ⅠX, GPIV and isolated HLA Class Ⅰ antigens. Among the 47 samples, 23 were sensitized to HLA and/or platelet antigens (48.94%). The 23 positive samples consisted of 34.78% of HLA Class Ⅰ antibodies, 39.13% of platelet-specific antibodies, and 26.09% consisted of both. Anti-GPⅡb/Ⅲa positive and anti-GPⅠa/Ⅱa positive were the most frequent among all the platelet-specific antibody positive cases. There is no statistical difference in the positive rate between ages. However, among antibody positive patients who have received transfusion, significant difference exists between females (78.95%, 15 out of 19) and males (40.00%, 8 out of 20) (p＜0.05). The data remained significant for comparison between platelet specific antibody positive rate and HLA Class Ⅰ antibody among hemodialysis patients. This study suggests that it is critical to establish a pool of Human Platelet Antigen (HPA) typed donors as well as a pool of HLA typed donors and provide the patients with matched blood components to aid in the reducing of the alloimmunization frequency in hemodialysis patients.