Listeria Monocytogenes
Infection with the intracellular bacterium Listeria monocytogenes (L. monocytogenes) in patients receiving biologic therapy is well-documented. An assessment of the incidence of Listeria infections in patients using TNF inhibitors was performed by comparing data from the Spanish Registry of Adverse Events of Biological Therapies in Rheumatic Diseases (BIOBADASER) with the Spanish Rheumatoid Arthritis Registry Cohort Study (EMECAR). RA patients treated with TNF-α antagonists had an increased rate of Listeria infection in comparison to RA patients treated with conventional therapy, as well as the general population.
A recent review described the first case of L. monocytogenes endocarditis associated with infliximab, and identified 92 cases of L. monocytogenes infections related to infliximab treatment in the FDA AERS database. Meningitis was the most common type of infection reported (69 cases, 75%), followed by sepsis (20 cases, 21.7%) and listeriosis (3 cases, 3.3%). Further information was lacking on most of the cases in the AERS database, however, additional immunosuppressive therapy was being used in 22 out of 24 cases detailed in the review. Infectious complications with Listeria are seen more frequently in patient treated with infliximab versus etanercept, perhaps because of the more versatile binding of infliximab to both soluble and cell surface TNF-α instead of predominantly soluble TNF-α. However, there have been several cases of L. monocytogenes septic arthritis in patients treated with etanercept. Adalimumab is reported less frequently in association with L. monocytogenes infections, but a case of L. monocytogenes meningitis with this therapy has been documented.