[An elderly case with pseudogout exacerbated by the administration of granulocyte-colony stimulating factor during drug-induced granulocytopenia].

A 82-year-old woman was admitted because of dehydration and chronic renal failure. Although her renal function was improved by hydration, granulocytopenia (granulocyte number 645/mm3) occurred. Treatment with a relatively high dose of H2 blocker for one month before admission may have caused the granulocytopenia. To prevent possible infection in the patient, we administered 75 g of granulocyte-colony stimulating factor (G-CSF) for 5 consecutive days but 4 days after commencement of administration of G-CSF, pain in both knee joints suddenly appeared. Synovial fluid aspiration revealed granulocytosis (10,400/mm3) and deposition of calcium pyrophosphate dihydrate in the knee joints. The level of G-CSF in the synovial fluid was increased in the joints (700 pg/ml), compared with the serum concentration (62 pg/ml). Furthermore, the concentrations of interleukin-6 and interleukin-8 were markedly increased in the synovial fluid. The results indicated that her pseudogout exacerbation by G-CSF was at least in part explained by the increased production of cytokines in the knee joints. Because the prevalence of pseudogout and gout is overwhelming in the elderly, the possibility of GCSF induced exacerbation of joint pain should be carefully considered in elderly patients.