Thrombotic thrombocytopenic purpura with severe ADAMTS-13 deficiency in two patients with primary antiphospholipid syndrome.
Arterial thrombotic events, thrombocytopenia, and hemolytic anemia with schistocytes may be encountered in the setting of both thrombotic thrombocytopenic purpura (TTP) and primary antiphospholipid syndrome (APS). We report 2 cases of TTP occurring in patients with definite primary APS. We also describe the results of tests for ADAMTS-13 activity in 20 consecutive patients with primary APS, as well as tests for antiphospholipid antibodies in 26 patients who had TTP, severe ADAMTS-13 deficiency, and ADAMTS-13-inhibiting antibodies. In both of the patients with primary APS and TTP, ADAMTS-13 activity was undetectable, and ADAMTS-13-inhibiting antibodies were present. None of the 26 patients with TTP and severe ADAMTS-13 deficiency was positive for the lupus anticoagulant. One of these patients had a low level of anticardiolipin antibodies (22 IgG phospholipid units). In the 20 patients with primary APS, mean ADAMTS-13 activity was 116% (range 44-250%), and no severe deficiency (< 5%) was observed. Our findings suggest that primary APS must be added to the list of autoimmune disorders that can be complicated by TTP.
Centre Hospitalier Universitaire Pitié-Salpêtrière, Paris, France. zahir.amoura@psl.ap-hop-paris.fr
Zahir
Z
Amoura
Nathalie
N
Costedoat-Chalumeau
Agnès
A
Veyradier
Martine
M
Wolf
Pascale
P
Ghillani-Dalbin
Patrice
P
Cacoub
Dominique
D
Meyer
Jean-Charles
JC
Piette
D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; D000293:Adolescent; D000328:Adult; D017153:Antibodies, Anticardiolipin / Q000097:blood; D016736:Antiphospholipid Syndrome / Q000150:complications*; D005260:Female; D006801:Humans; D016682:Lupus Coagulation Inhibitor / Q000032:analysis; D008666:Metalloendopeptidases / Q000172:deficiency* / Q000276:immunology; D011697:Purpura, Thrombotic Thrombocytopenic / Q000150:complications*
D017153:Antibodies, Anticardiolipin; D016682:Lupus Coagulation Inhibitor; D051722:ADAM Proteins; D008666:Metalloendopeptidases; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human