gms | German Medical Science

Background: Increased risks for infectious diseases, in particular for tuberculosis,(Tbc) has been reported in patients receiving treatment with TNF-α-inhibitors. The cytokine TNF-α plays a central role in the development and maintenance of granuloma. Activation of macrophages by specific T-cells with TNF-α is an essential component in intracellular killing of mycobacteria. The risk of mycobacterial infection has been shown to be highest within the first 2 years of commencing treatment. In our case the patient had received the soluble TNF-α-receptor etanercept for 5 years due to rheumatoid arthritis, and had been switched to the monoclonal anti-TNF-α antibody adalimumab 30 months prior to the onset of oral ulceration.

Case report: A 70 year old patient with rheumatoid polyarthritis being treated with TNF-alpha-Inhibitor immunosuppression and metothrexate was admitted to our maxillo-facial surgery department due to treatment refractory oral ulceration and persisting mucosal swelling within the left maxilliary sinus. Multiple mucosal biopsies were taken showing necrotising granulomatous inflammation.An Interferon-gamma release assay (IGRA) for Tbc was positive. Microbiological cultures and subsequent 16s-RNA sequencing confirmed M. Tbc var. bovis. The patient received a quadruple therapy with isoniazide, rifampin, ethambutol, and pyrazinamide (PZA). PZA was switched to Moxifloxacin when genotyping revealed M. bovis, which is primarily resistant against PZA. Antibuberculous therapy resulted in rapid improvement in clinical condition.

Conclusion: In the case of an atypically presenting ulceration or presumed infection, which is refractory to empirical antibiotic treatment, particularly within immunosuppressed populations, consideration should always be given to mycobacterial infections. Prior to TNF-alpha-inhibtor therapy screening for previous tuberculosis exposure should be performed. Additionally, detailed and directed history taking are vital in determining „at-risk“ patients. Such enquiries are also mandatory when confronted with atypically behaving infections whilst under treatment. In 1952, a time when M. bovis was endemic in cattles in Germany, the patient's husband had confirmed tuberculosis. At that time the patient and her husband lived on a farm with a large herd of cattle.To our knowledge this is the first description of a case of reactivated Tbc in man presenting exclusively in the oral cavity.