[Biologics and mycobacterial diseases].

Various biologics such as TNF-alpha inhibitor or IL-6 inhibitor are now widely used for treatment of rheumatoid arthritis. Many reports suggested that one of the major issues is high risk of developing tuberculosis (TB) associated with using these agents, which is especially important in Japan where tuberculosis still remains endemic. Another concern is the risk of development of nontuberculous mycobacterial (NTM) diseases and we have only scanty information about it. The purpose of this symposium is to elucidate the role of biologics in the development of mycobacterial diseases and to establish the strategy to control them. First, Dr. Tohma showed the epidemiologic data of TB risks associated with using biologics calculated from the clinical database on National Database of Rheumatic Diseases by iR-net in Japan. He estimated TB risks in rheumatoid arthritis (RA) patients to be about four times higher compared with general populations and to become even higher by using biologics. He also pointed out a low rate of implementation of QuantiFERON test (QFT) as screening test for TB infection. Next, Dr. Tokuda discussed the issue of NTM disease associated with using biologics. He suggested the airway disease in RA patients might play some role in the development of NTM disease, which may conversely lead to overdiagnosis of NTM disease in RA patients. He suggested that NTM disease should not be uniformly considered a contraindication to treatment with biologics, considering from the results of recent multicenter study showing relatively favorable outcome of NTM patients receiving biologics. Patients with latent tuberculosis infection (LTBI) should receive LTBI treatment before starting biologics. Dr. Kato, a chairperson of the Prevention Committee of the Japanese Society for Tuberculosis, proposed a new LTBI guideline including active implementation of LTBI treatment, introducing interferon gamma release assay, and appropriate selection of persons at high risk for developing TB. Lastly, Dr. Matsumoto stressed the risk of discontinuing TNF-alpha inhibitor during treatment for tuberculosis. He showed from his clinical experience that TNF-alpha inhibitor can be safely used in active TB patient receiving effective antituberculosis chemotherapy and it is even more effective for prevention of paradoxical response. Active discussion was done about the four topics, including the matter beyond present guidelines. We hope these discussions will form the basis for the establishment of new guideline for the management of mycobacterial disease when using immunosuppressive agents including biologics. 1. The risk of developing tuberculosis (TB) and situations of screening for TB risk at administration of biologics-the case of rheumatoid arthritis: Shigeto TOHMA (Clinical Research Center for Allergy and Rheumatology, National Hospital Organization Sagamihara National Hospital) We calculated the standardized incidence ratio (SIR) of TB from the clinical data on National Database of Rheumatic Diseases by iR-net in Japan (NinJa) and compared with the SIR of TB from the data of the post-marketing surveillances of five biologics. Among 43584 patient-years, forty patients developed TB. The SIR of TB in NinJa was 4.34 (95%CI: 3.00-5.69). According to the post-marketing surveillances of 5 biologics, the SIR of TB were 3.62-34.4. The incidence of TB in patients with RA was higher than general population in Japan, and was increased more by some biologics. We have to recognize the risk of TB when we start biologics therapy to patients with RA. Although the frequency of implementation of QuantiFERON test (QFT) had gradually increased, it was still limited to 41%. In order to predict the risk of developing TB and to prevent TB, it might be better to check all RA patients by QFT at time time of biologics administration. 2. Biologics and nontuberculous mycobacterial diseases: Hitoshi TOKUDA (Social Insurance Central General Hospital) Several topics about the relationship between RA and nontuberculous mycobacterial (NTM) diseases were discussed, which is still poorly understood. It is well known that airway diseases often accompany RA, which may be considered as a possible etiology for development of NTM diseases, but conversely it may lead to overdiagnosis of NTM disease. Next, we evaluated justification for the contraindication of biologics in patients with NTM diseases. Recent multicenter study showed that prognosis of patients developing NTM diseases during treatment with biologics were not always poor, which throws doubt on uniform prohibition of biologics in NTM diseases. 3. Future guideline for treating latent tuberculosis infection: Seiya KATO (Research Institute of Tuberculosis, Japan AntiTuberculosis Association) The Japanese Society for Tuberculosis issued a joint statement on chemoprophylaxis with the Japan College of Rheumatology in 2004. However, issues and challenges due to changing circumstance indicate application of interferon gamma release assay (IGRA), increased variety and indication of biologics, dissemination of knowledge on strategy and system for latent tuberculosis infection (LTBI), etc. Future guideline should include 1) promoting LTBI treatment to achieve low incidence, 2) updated information on IGRAs, 3) treatment strategy and target: contact to infectious cases, immunosuppressive cases (especially HIV and patients treated with biologics), high risk groups, etc. 4) fundamental information on tuberculosis control strategies, especially DOTS. 4. Therapy for RA and tuberculosis in patients with RA and TB activated by anti-TNF treatment: Tomoshige MATSUMOTO (Osaka Prefectural Medical Center for Respiratory and Allergic Diseases) Biologics targeting TNF, including infliximab, have brought about a paradigm shift in the treatment of rheumatoid arthritis (RA). In 2001, tuberculosis, an ancient and also modem scourge, became spotlighted again, because Keane reported in the New England Journal of Medicine that infliximab administration induced reactivation of tuberculosis. How should we treat RA after we successfully treated tuberculosis? Decisions regarding the treatment of patients with refractory RA in the setting of active tuberculosis remain difficult. We successfully treated RA in patients with tuberculosis by anti-TNF therapy. These demonstrate that anti-TNF therapy can be considered for patients with refractory RA who have tuberculosis and in whom antituberculosis therapy can be maintained.