title: Secondary myelodysplastic syndrome after hydroxychloroquine therapy.
abstract: Primary myelodysplastic syndromes (MDS) occur in the absence of exposure to ionizing radiation, chemotherapeutic agents or myelotoxic drugs, whereas secondary MDS occurs in the presence of such exposure. We encountered 4 patients among 217 patients on hydroxychloroquine for rheumatological conditions in 2005 diagnosed with MDS. Two patients were male and two were female; the median age was 69.75 years, (range 65-76). The dose of hydroxychloroquine for all patients was 400 mg daily with median treatment duration of 10.5 years and a range of 6-16. All patients had bone marrow biopsy confirmation of the diagnosis of MDS. The incidence of MDS in a group older than 70 years ranges from 15 to 50/100,000 persons per year. The diagnosis of 4 cases of MDS among 217 patients in 1 year is approximately 123-137-fold higher than the risk of MDS in the general population aged more than 70 years (P < 0.001) and suggests that long-term treatment with hydroxychloroquine is associated with an increased risk of developing secondary MDS.
authors.forename: Alaa A
authors.initials: AA
authors.lastname: Muslimani
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Spiro
authors.forename: Asif A
authors.initials: AA
authors.lastname: Chaudhry
authors.forename: Hamed A
authors.initials: HA
authors.lastname: Daw
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D006886:Hydroxychloroquine / Q000009:adverse effects*; D008297:Male; D009190:Myelodysplastic Syndromes / Q000139:chemically induced*; D012189:Retrospective Studies; D012216:Rheumatic Diseases / Q000188:drug therapy*
chemical_list: D006886:Hydroxychloroquine