Listeria meningitis associated with infliximab

OBJECTIVE: To report a case of Listeria monocytogenes meningitis in a 73-year-old man receiving infliximab for rheumatoid arthritis. CASE SUMMARY: A 73-year-old white man taking infliximab for rheumatoid arthritis developed listeria meningitis following his second dose. He was receiving other immunosuppressants; however, these remained constant immediately prior to the infection. Diagnosis was confirmed with L. monocytogenes isolated in the cerebrospinal fluid. The patient received 21 days of antibiotic therapy and recovered without any complications. DISCUSSION: L. monocytogenes is a gram-positive, non-spore-forming rod that has been associated with the ingestion of undercooked foods. This organism can cause sepsis or meningitis; however, immunocompromised patients, elderly patients, pregnant women, and neonates appear to be at greater risk for this type of infection. Tumor-necrosis factor-alpha (TNF-alpha) plays an important role in resistance to this type of infection, and listeria infections have been reported in 26 patients receiving TNF-alpha inhibitors. In our patient, the listeria infection occurred following his second course of infliximab, which provides a temporal relationship between the listeria infection and infliximab. However, his underlying rheumatoid arthritis and chronic steroid therapy would also increase his risk for a listeria infection. CONCLUSIONS: The listeria infection in our patient was a possible adverse event of infliximab according to the Naranjo probability scale. Because the majority of listeria infections occur in patients who are immunosuppressed, it would be reasonable to provide education for healthcare professionals on preventing these infections in all patients receiving immunosuppressants, including anti-TNF-alpha therapy. Those at risk due to their underlying health conditions should also be monitored closely.