Identification of the platelet-specific alloantigen, Naka, on platelet membrane glycoprotein IV

Abstract

We describe the membrane localization of a new platelet-specific alloantigen, designated Naka, that is involved in refractoriness to HLA- matched platelet transfusions. By indirect immunoprecipitation, anti- Naka antibody precipitated a single, radiolabeled platelet membrane protein with a molecular weight (mol wt) of 91 Kd from Naka-positive platelets. When radiolabeled Naka-negative platelets were used as a source of target antigens, no radiolabeled proteins were precipitated. The analyses using nonreduced-reduced two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and using rabbit antiglycoprotein (GP)IV demonstrated that this protein corresponds to GPIV (alternatively GPIIIb). Furthermore, in dot immunobinding, anti- Naka antibody bound to purified GPIV. Our results provide definitive evidence that the Naka alloantigen is carried on GPIV. These results also demonstrate that, on occasion, antibodies against GPIV may play an important role in refractoriness to platelet transfusions.

Frequency of CD36 deficiency in Thais analyzed by quantification of CD36 on cell surfaces and in plasma

“…In this study, we found that around 0.43% of Thai blood donors exhibit Type I CD36 deficiency and are therefore at risk of developing anti-CD36 antibodies if exposed to the antigen through transfusion or pregnancy. 2 These antibodies can cause PTR and serious FNAIT, as recently reported in different Asian populations. 3,4 Indeed, a case of FNAIT has been reported in Thailand.…”

“…Individuals with CD36 Type I deficiency can develop anti-CD36 antibodies during pregnancy or upon transfusion, a phenomenon that is responsible for a number of immune-mediated platelet disorders such as fetal/neonatal alloimmune thrombocytopenia (FNAIT), platelet transfusion refractoriness (PTR), and posttransfusion purpura. [2][3][4] In addition, anti-CD36s have been found in cases of transfusionrelated acute lung injury. 5 However, the exact mechanism by which anti-CD36s mediate these disorders is currently not fully understood.…”

Role of anti‐Naka antibody, monocytes and platelets in the development of transfusion‐related acute lung injury

“…Nak a (CD36) is a major glycoprotein (GP) of platelets and is known as GPIV [14]. Nak a is also distributed among monocytes, capillary endothelium cells, epithelial cells and megakaryocytes [15].…”

Primary refractoriness to platelet transfusion caused by Naka antibody alone

“…Nak a antigen is localized on platelet glycoprotein (GP) IV or CD36 [9]. There are two types of platelet CD36 deficiencies.…”