Myelosuppression in rheumatoid arthritis patient treated with methotrexate : A case report

Abstract

Myelosuppression has been known to be an uncommon but life-threatening condition of methotrexate. Methotrexate level has been used for the diagnosis of methotrexate induced myelosuppression. Methotrexate level rapidly declines after cessation.  Therefore, early detection of methotrexate level is important for diagnosing this condition.

This case report presented a 79-year-old female patient with rheumatoid arthritis and hypertension. She had been prescribed with methotrexate 10 mg per week for 6 months without folic acid supplement. The patient had an abnormal bleeding symptom, petechiae, oral ulcer and melena for one month. Laboratory results showed decrease in hemoglobin level, white blood cell and platelet (indicating pancytopenia). The overall symptoms and laboratory investigation indicated the possibility of methotrexate-induced myelosuppression. The laboratory result of methotrexate level was <0.02 μmol/L, therefore, the bone marrow and chromosome study were performed to exclude acute leukemia. However, once methotrexate was discontinued and leucovorin was prescribed for 2 weeks, the overall laboratory results for myelosuppression were improved. Thus, the patient was diagnosed with methotrexate-induced myelosuppression. After methotrexate discontinuation, no laboratory results showed abnormality.