The Natural History of Alloimmunization to Platelets

Abstract

Sixty-three patients have provided evidence that platelets are highly immunogenic even in recipients of potentially immunosuppressive therapy for malignant diseases. Approximately 70 per cent of patients who receive repeated transfusions of platelets from random donors over a prolonged period can be expected to develop lymphocytotoxic antibodies. Antibodies became detectable in one patient ten days after his first exposure to HLA antigens in the form of platelet concentrates, and as early as four days in two patients with prior exposure to HLA antigens. In the most heavily immunized patients, the presence of antibody correlated with poor increments of platelets after transfusion. Patients with prior exposure to HLA antigens are more likely to have antibodies resulting in poor platelet survival. On the other hand, 30 per cent of recipients of repeated platelet transfusions show no tendency to form cytotoxic antibodies.

Postoperative Decrease in Platelet Counts Is Associated with Delayed Liver Function Recovery and Complications after Partial Hepatectomy

“…This hypothesis is supported by a report from Kim et al (2010) showing that platelet transfusion volume after liver transplantation from living related donors was positively correlated with graft regeneration. However, there are several critical obstacles that need to be overcome before exploiting platelets in clinical practice, including the production of anti-platelet antibodies following platelet transfusion (Howard and Perkins 1978), the production of anti-thrombopoietin antibodies after thrombopoietin administration (Wormann 2013), and the severalday delay between thrombopoietin-receptor agonist administration and increases in platelet counts (Schipperus and Fijnheer 2011). Further research is necessary to determine the optimal treatment methods and time intervals for increasing postoperative platelet counts.…”

Low-level HLA antibodies do not predict platelet transfusion failure in TRAP study participants

“…With platelet transfusions, these responses are generally toward HLAs expressed on WBCs and platelets and/or other platelet antigens and can result in refractoriness to subsequent platelet transfusions. 1,2 The generation of antibodies against HLA antigens is particularly common, with rates ranging from 7% to 55% after platelet transfusion, depending on study, patient population, and number and type of transfusions. 1,[3][4][5][6][7][8][9] These antibodies are usually detected within the first 2 weeks after exposure and can be either short-lived or persist long after transfusion.…”

“…1,2 The generation of antibodies against HLA antigens is particularly common, with rates ranging from 7% to 55% after platelet transfusion, depending on study, patient population, and number and type of transfusions. 1,[3][4][5][6][7][8][9] These antibodies are usually detected within the first 2 weeks after exposure and can be either short-lived or persist long after transfusion. 3,4,[10][11][12][13] Leukoreduction of platelets has been shown in most studies to reduce the frequency of, but not eliminate, alloimmunization, 3,[5][6][7][8]14 although not necessarily in previously pregnant recipients.…”

Empfehlungen zur Thrombozytentransfusion der Thrombozyten-Arbeitsgruppe der DGTI, GTH und DGHO

“…Antikörper gegen HLA-Klasse-I-Antigene sind die häufigste Ursache für einen immunologisch induzierten Refraktärzu-stand [67,68]. Der Nachweis erfolgt mit komplementunab- [92].…”