title: Patients with essential thrombocythaemia have an increased prevalence of antiphospholipid antibodies which may be associated with thrombosis.
abstract: A significant proportion of patients with Essential Thrombocythaemia (ET) have thrombotic complications which have an important impact upon the quality, and duration of their life. We performed a retrospective cross sectional study of the prevalence of antiphospholipid antibodies (APA) in 68 ET patients. Compared to 200 "elderly" controls (>50 years) there was a significant increase in anticardiolipin IgM (p < 0.0001) and anti beta2 glycoprotein I (anti-beta2GPI) IgM (p < 0.0001) antibodies in ET. Thrombosis occurred in 10/20 with APA and 12/48 without, p = 0.04, relative risk 2.0 (95% confidence intervals 1.03-3.86): these patients did not differ in terms of other clinical features. The prevalence of thrombosis in patients with dual APA (6/7) was significant when compared to those with single APA (p = 0.02) and the remaining patients (p < 0.0002). Also anti-beta2GP1 IgM antibodies either alone, or in combination with another APA, were associated with thrombosis (p = 0.02). These results suggest that the prevalence of APA in ET and their influence upon thrombotic risk merit investigation in a larger study.
authors.affiliation: Department of Haematology, University College London Hospital, UK. claire.harrison@gstt.sthames.nhs.uk
authors.forename: C N
authors.initials: CN
authors.lastname: Harrison
authors.forename: S
authors.initials: S
authors.lastname: Donohoe
authors.forename: P
authors.initials: P
authors.lastname: Carr
authors.forename: M
authors.initials: M
authors.lastname: Dave
authors.forename: I
authors.initials: I
authors.lastname: Mackie
authors.forename: S J
authors.initials: SJ
authors.lastname: Machin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000477:Alkylating Agents / Q000627:therapeutic use; D017153:Antibodies, Anticardiolipin / Q000097:blood; D017152:Antibodies, Antiphospholipid / Q000097:blood* / Q000276:immunology; D000918:Antibody Specificity; D016736:Antiphospholipid Syndrome / Q000150:complications / Q000453:epidemiology / Q000276:immunology; D001324:Autoantigens / Q000276:immunology; D001327:Autoimmune Diseases / Q000150:complications / Q000453:epidemiology / Q000276:immunology* / Q000628:therapy; D002648:Child; D002999:Clone Cells / Q000473:pathology; D003430:Cross-Sectional Studies; D005260:Female; D006023:Glycoproteins / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D016898:Interferon-alpha / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D010761:Phosphorus Radioisotopes / Q000627:therapeutic use; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D015995:Prevalence; D012189:Retrospective Studies; D013920:Thrombocythemia, Essential / Q000150:complications / Q000453:epidemiology / Q000276:immunology* / Q000628:therapy; D019851:Thrombophilia / Q000453:epidemiology / Q000209:etiology*; D013927:Thrombosis / Q000453:epidemiology / Q000209:etiology* / Q000276:immunology; D053482:beta 2-Glycoprotein I; D001613:beta 2-Microglobulin / Q000276:immunology
chemical_list: D000477:Alkylating Agents; D017153:Antibodies, Anticardiolipin; D017152:Antibodies, Antiphospholipid; D001324:Autoantigens; D006023:Glycoproteins; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D016898:Interferon-alpha; D010761:Phosphorus Radioisotopes; D010975:Platelet Aggregation Inhibitors; D053482:beta 2-Glycoprotein I; D001613:beta 2-Microglobulin