Etiology and Incidence of Thrombotic and Hemorrhagic Disorders in Thai Patients with Extreme Thrombocytosis
SUPORN CHUNCHARUNEE, M.D.*, ARTIT UNGKANONT,M.D.*, PANTEP ANGCHAISUKSIRI, M.D.*, SOPHARK ROJANASTHEIN, M.Sc.***, NAPAPORN ARCHARARIT, M.Sc.**, SAENGSUREE JOOTAR, M.D.*, AHNOND BUNYARATAVEJ, Ph.D.***, VICHAI ATICHARTAKARN, M.D.*
Affiliation : * Department of Medicine, **Research Center, ***Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand.
A retrospective study of 126 patients with extreme thrombocytosis (defined as a platelet count ~1,000 x 109/L) was performed during a five-year period (June 1994- June 1999). The aim of this study was to determine the etiology and to evaluate the clinical consequences of extreme thrombocytosis. Seventy patients (55.5%) had reactive thrombocytosis (RT) with an age range of 43 ± 2.2 years, 56 (44.5%) had chronic myeloproliferative disorders (MPD) with an age range of 53 ± 2.4 years. Underlying causes of RT were malignancy (25170 or 35.7%), infec- tion (16170 or 22.9%), postsplenectomized B-thalassemia/Hb E (11/70 or 15.7%), inflammation (12170 or 17.1%), iron deficiency anemia (6170 or 8.6%). Duration post splenectomy in our B-tha- lassemia/Hb E patients ranged from 4 months to 21 years, with a median of lO years. Subtypes of our MPD cases were chronic myeloid leukemia (30/56 or 53.6%), essential thrombocytosis (18/56 or 32.1%), polycythemia vera (4/56 or 7.1%), agnogenic myeloid metaplasia (3/56 or 5.4%) and unclassified MPD (1156 or 1.8%). Bleeding and thrombotic tendency were respec- tively noted in 7 (12.5%) and 2 (3.6%) of MPD patients. Two patients of the MPD group (3.6o/r) experienced both bleeding and thrombotic episodes. One patient (1.4%) of the RT group developed vasculitis-associated thrombosis. However, none of the patients in the RT group had bleeding com- plications. Extreme thrombocytosis was not a rare condition in a university hospital population, and bleeding and/or thrombotic complication was more common in the MPD group.
Keywords : Extreme Thrombocytosis, Chronic Myeloproliferative Disorder (MPD), Postsplenec-tomized B-thalassemia/Hb E, Reactive Thrombocytosis (RT), Thrombotic, Hemorrhagic.
