The development of infections from mycobacteria and fungi endemic to U.S. regions in patients taking tumor necrosis factor–alpha inhibitors (TNFIs) is rare and is not influenced by prescreening of targeted infections, research suggests.
A case-control study of 30,772 patients taking TNFIs showed that only 158 (0.51%) patients developed the fungal and/or mycobacterial infections targeted in this study, with tuberculosis and histoplasmosis being the most common infections.
Targeted infections were nontuberculous mycobacterial infection, blastomycosis, coccidioidomyocosis, cryptococcal infection, histoplasmosis, pneumocystosis, tuberculosis disease, and unspecified fungal infection.
Prednisone was the only predictive factor for infection and was associated with a twofold increase in the likelihood of patients seeking medical attention for a fungal or mycobacterial infection, which the authors said was supported by previous research, according to a paper published online in Arthritis & Rheumatology.
“Thus, the question remains if the increased infection rates are related solely to the use of the glucocorticoids or the active disease for which the medication is being prescribed,” wrote Elizabeth Salt, Ph.D., of the University of Kentucky, Lexington, and coauthors (Arthritis Rheumatol. 2015 Oct 16 doi: 10.1002/art.39462).
Researchers also noted that sulfamethoxazole-trimethoprim was associated with a nonsignificant 45% increase in the likelihood of requiring medical care, compared with controls.
“It is possible that providers recognized the infectious risk of this population and made attempts at controlling infectious processes among those most vulnerable.”
The study was supported by the National Institutes of Health. There were no conflicts of interest declared.