Effect of intravenous immunoglobulin on inhibition of fibrinogen binding to platelets by sera from patients with immune thrombocytopenia
✍ Scribed by Dr. Mikio Kamiyama; Yuichi Yoshimura; Karen Chen; Yale S. Arkel
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 630 KB
- Volume
- 44
- Category
- Article
- ISSN
- 0361-8609
No coin nor oath required. For personal study only.
✦ Synopsis
We previously described an ELSA to measure the inhibition of platelet glycoprotein Ilb/llla (GPllblllla) binding to fibrinogen due to immune complexes and/or anti-platelet antibodies from patients with immune thrombocytopenia (ITP) or HIV-related ITP. Circulating immune complexes (CIC) were the main factor in the inhibition of GPllb/llla binding to fibrinogen in HIV-related ITP, whereas in non-HIV ITP, inhibition was only partially due to CIC; anti-platelet antibodies specific to GPllla were also shown to play a role. In this study, we correlated the rise in the platelet count after intravenous immunoglobulin (IVIG) infusion with the decrease in inhibition of fibrinogen binding to GPllbillla by the sera of patients with ITP and HIV-related ITP. In the majority of the patients' sera tested, as the platelet count increased following the administration of WIG, the degree of inhibition of GPllb/llla binding to fibrinogen decreased. We also observed a decrease and/or disappearance of the antibodies specific to GPllb and/or GPllla after WIG administration. In HIV-seronegative ITP patients, the decrease or disappearance of anti-platelet antibodies directly correlated with the decreased inhibition of GPllb/llla binding to fibrinogen by the 2% PEG supernatants of sera which contained anti-platelet antibodies. These findings suggest that WIG directly affects the binding of CIC and anti-platelet antibodies to platelets and thereby improves platelet survival. Our results also suggest that the anti-idiotypic effect may contribute to IVIG's therapeutic action. In contrast, in the HIV-seropositive group, the decreased inhibition by PEG precipitates after IVlG administration was more strongly associated with an increase in the platelet count.