phosphorus-radioisotopes and Thrombophilia

Hydroxyurea is an old drug that is often used to control essential thrombocythemia and polycythemia vera in patients with high-risk disease. It is usually well tolerated and cheap and has been proven effective in many studies for the prevention of thrombohemorrhagic complications associated with these disorders. However, many clinicians are reluctant to use it because of the perceived risk of progression to acute leukemia. Several recent, large studies have given this drug a new lease on life. Relevant results from these studies are discussed, and the risk of leukemia is placed in perspective to demonstrate that hydroxyurea remains the drug of choice in patients with either of these disorders.

Topics: Aged; Agranulocytosis; Alkylating Agents; Clinical Trials as Topic; Combined Modality Therapy; Disease Progression; Evidence-Based Medicine; Hemorrhage; Humans; Hydroxyurea; Leukemia, Myeloid, Acute; Middle Aged; Phlebotomy; Phosphorus Radioisotopes; Polycythemia Vera; Thrombocythemia, Essential; Thrombophilia

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.

Topics: Adult; Aged; Aged, 80 and over; Alkylating Agents; Antibodies, Anticardiolipin; Antibodies, Antiphospholipid; Antibody Specificity; Antiphospholipid Syndrome; Autoantigens; Autoimmune Diseases; beta 2-Glycoprotein I; beta 2-Microglobulin; Child; Clone Cells; Cross-Sectional Studies; Female; Glycoproteins; Humans; Immunoglobulin G; Immunoglobulin M; Interferon-alpha; Male; Middle Aged; Phosphorus Radioisotopes; Platelet Aggregation Inhibitors; Prevalence; Retrospective Studies; Thrombocythemia, Essential; Thrombophilia; Thrombosis