A Case of Early Aplastic Anemia due to Low Dose Methotrexate in Rheumatoid Arthritis / 대한류마티스학회지

ABSTRACT

Low dose methotrexate (MTX) is widely used for treatment of rheumatoid arthritis (RA) due to prompt clinical response, relatively lack of serious side effects, tolerability and simplicity of medication. However, several serious adverse effects have been reported with the use of MTX. The prevalence of hematologic toxicity, including leukopenia, thrombocytopenia, megaloblastic anemia, and pancytopenia, is estimated to be 3% in MTX-treated RA patients. Pancytopenia, which occurs unpredictably, is one of the most serious adverse effects and the prevalence is estimated to be 1.4% and fatal pancytopenia reported to occur in 17% of these patients. Old age, impaired renal function, concurrent infection, hypoalbuminemia, increased mean corpuscular volume of red blood cell, concomitant medication such as trimethoprim-sulfamethoxazole and nonsteroidal antiinflammatory drug, are the risk factors of MTX induced pancytopenia. We experienced a case of fatal MTX induced early aplastic anemia in RA patients who medicated 3 times MTX (7.5mg/weekly, 22.5mg of cumulative dose) refractory to treatment with steroid pulse, recombinant human granulocyte macrophage colony stimulating factor (rhGM-CSF) and immunoglobulin.