Specificities of platelet autoantibodies in patients with lupus anticoagulants in primary antiphospholipid syndrome.
We have studied target platelet antigens in 22 patients with lupus anticoagulants and a primary antiphospholipid syndrome in order to determine whether any specificities of platelet autoantibodies are correlated with thromboembolism, and if these antibodies cross-react with phospholipids, which would suggest their role in the development of thromboembolic disease. Platelet counts were median 203 x 10(9)/l, range 100-298 x 10(9)/l. Platelet antibodies were found in six thrombocytopenic patients and in further nine patients. All these 15 patients had antibodies against GPIIb/ IIIa, five patients against GPIb/IX, and six patients against GPIV. Anti-GPIb/IX and -GPIV occurred only in combination with anti-GPIIb/IIIa antibodies. There was no correlation between the presence of detectable platelet antibodies or any of their glycoprotein specificity and thrombocytopenia or the history of a thromboembolic disease. Eluates from platelets contained only GPIIb/IIIa reactivities, but neither anti-GPIb/IX nor anti-GPIV. None of the eluates contained lupus anticoagulant activity. In one case, the platelet eluates contained anti-GPIIb/IIIa and anticardiolipin IgG antibodies. These results suggest that in patients with a primary antiphospholipid syndrome the presence of platelet autoantibodies neither indicate a risk for thromboembolic disorder nor have lupus anticoagulant activity.
Panzer
S
S
Clinical Department for Blood Group Serology, University of Vienna, Austria.
Gschwandtner
M E
ME
Hütter
D
D
Spitzauer
S
S
Pabinger
I
I
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000918:Antibody Specificity; D016824:Antigens, Human Platelet / Q000276:immunology*; D016736:Antiphospholipid Syndrome / Q000276:immunology*; D001323:Autoantibodies / Q000276:immunology; D005260:Female; D006801:Humans; D016682:Lupus Coagulation Inhibitor / Q000097:blood*; D008297:Male; D008875:Middle Aged; D013923:Thromboembolism / Q000097:blood
D016824:Antigens, Human Platelet; D001323:Autoantibodies; D016682:Lupus Coagulation Inhibitor