MYCOBACTERIUM-TUBERCULOSIS INFECTION IN A CORTICOSTEROID-TREATED RHEUMATIC DISEASE PATIENT POPULATION

Objective To investigate the incidence and risk factors of Mycobacteri um tuberculosis infection ill longterm corticosteroid treated rheumati c disease patients. Methods We assessed retrospectively the incidence of active tuberculosis and its risk factors in 269 rheumatic disease p atients treated with moderate to high doses of corticosteroid for an e valuation period representing 1,035 corticosteroid years of therapy. R esults The mean daily dose of steroid was 18.7 mg prednisolone and the mean daily dose during the first year of treatment was 20.4 mg predni solone. 21 of these patients developed active tuberculosis resulting i n an incidence rate of 20/1,000 patient-years. Cumulative and mean dai ly steroid doses during the follow-lip period and during the first yea r of treatment, and a history of steroid pulse therapy were significan tly correlated with the development of tuberculosis. A past history of tuberculosis, initial chest P-A abnormality the starting dose of ster oid, a history of more than 30 mg/day of prednisolone for more than on e month, and a history of cytotoxic therapy were not related to the de velopment of tuberculosis. Conclusion The incidence of active tubercul osis is increased in rheumatic patients on moderate-to-high dose stero id treatment. Its risk factors are the cumulative and mean daily stero id doses during the follow-up period and during the first year of ster oid treatment, and a history of steroid pulse therapy.