PANCYTOPENIA RELATED EOSINOPHILIA IN RHEUMATOID-ARTHRITIS - A SPECIFIC METHOTREXATE PHENOMENON

Methotrexate (MTX) induced pancytopenia has been reported in about 3% of patients with rheumatoid arthritis (RA) receiving low dose MTX. We describe 4 additional patients with RA (2M, 2F; mean age 65 yrs; mean duration of RA 9 yrs) who developed pancytopenia while receiving low d ose MTX, Risk factors identified for the development of pancytopenia i n our patients included impaired renal function, hypoalbuminemia, adva nced age, low folate level, concurrent use of multiple comedication, n onsteroidal antiinflammatory drugs, and cotrimoxazole). Remarkably, pa ncytopenia related eosinophilia was observed in blood and bone marrow after restoring the intracellular folate level by folinic acid, The ra nge of eosinophils was 22-56% of the number of peripheral white blood cells (mean nadir 33%). The peak level of eosinophilic granulocytes wa s reached after a mean of 6 days in hospital (range 4-8), whereas the peak of neutrophils was reached after a mean of 11 days (range 9-13 da ys). The duration of the eosinophilic response was 11 days. As eosinop hilia has not been observed in other drug induced pancytopenias in pat ients with RA this could be a specific MTX induced phenomenon.