Interferon-α is not elevated in idiopathic thrombotic thrombocytopenic purpura patients.
Idiopathic thrombotic thrombocytopenic purpura (TTP) patients have ADAMTS13 deficiency, which is usually caused by ADAMTS13 autoantibodies. However, the triggering factors for the autoantibody production remain unclear. Interferon-α (IFN-α) is a cytokine involved with many autoimmune processes such as inducing the activation of peripheral dendritic cells and stimulating T cells and B cells. It also plays an important role in some autoimmune diseases. Elevated IFN-α levels have been observed in some TTP patients and previous case reports have shown the occurrence of TTP after IFN-α treatment. Thus, we hypothesized that high levels of IFN-α would correlate with presence of ADAMTS13 autoantibodies. However, we did not observe elevated IFN-α levels in 36 TTP patients (mean 5.29 pg/ml, standard deviation (SD) 26.56 pg/ml) compared to healthy controls (mean 0 pg/ml, SD 0 pg/ml), P = 0.59. IFN-α levels of most patients (94%) were undetectable. Only two patients had increased IFN-α levels and ADAMTS13 autoantibodies were detected in these two patients. Interestingly, both the patients had an underlying autoimmune disease. Although there have been cases of secondary TTP following IFN-α treatment, no evidence supports a role of IFN-α in the development of idiopathic TTP in our patient population.
Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, North Carolina; Transfusion Medicine Unit, King Chulalongkorn Memorial Hospital, Bangkok, Thailand.
Phandee
P
Watanaboonyongcharoen
Herbert C
HC
Whinna
Yara A
YA
Park
D051722:ADAM Proteins / Q000276:immunology; D000071120:ADAMTS13 Protein; D000328:Adult; D001323:Autoantibodies / Q000097:blood / Q000276:immunology; D001327:Autoimmune Diseases / Q000097:blood / Q000150:complications / Q000276:immunology; D001781:Blood Component Removal; D005260:Female; D006801:Humans; D016898:Interferon-alpha / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011697:Purpura, Thrombotic Thrombocytopenic / Q000097:blood* / Q000150:complications / Q000276:immunology / Q000628:therapy; D057049:Thrombotic Microangiopathies / Q000097:blood / Q000628:therapy
D001323:Autoantibodies; D016898:Interferon-alpha; D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human
ADAMTS13 autoantibodies; interferon-α; thrombotic thrombocytopenic purpura