Tuberculosis and Nontuberculous Mycobacterial Infections in Patients with Spondyloarthritis: A Population-Based Study.

Background and Objectives: Tuberculosis is caused by Mycobacterium tuberculosis (MTB), while nontuberculous mycobacteria (NTM) encompass a group of mycobacterial species that are distinct from the MTB complex and leprae. Spondyloarthritis (SpA) is a group of chronic inflammatory diseases with shared clinical characteristics and is treated with biological agents; however, their use may elevate the risk of MTB and NTM infections. This study aimed to compare the incidence and risk of MTB and NTM infections in patients with SpA, including ankylosing spondylitis (AS) and psoriatic arthritis (PsA), using a population-based approach. Materials and Methods: This study included 2333 patients with SpA and 9332 age- and sex-matched controls from the Korea National Health Insurance Service-National Sample Cohort database from 2002 to 2019. The patients were identified using the International Classification of Diseases-10 codes for AS, PsA, MTB, and NTM. Results: The results showed that a negligible percentage of patients with SpA developed NTM (0.002%) and MTB (0.016%), with no significant difference in the incidence rate ratio (IRR) compared to controls. Among patients with SpA treated with biologics, the IRRs for NTM and MTB were 5.66 and 3.069, respectively; however, these were not statistically significant. No cases of NTM or MTB infection were reported in female patients with SpA treated with biologics. In both the SpA patient group and the control group, the incidence of MTB was higher in individuals over 60 years old compared to those under 60 years old. Cox proportional hazard analysis revealed a significant adjusted hazard ratio of 1.479 for MTB in patients with SpA after adjusting for age, sex, smoking history, insurance level, and comorbidities. However, this significance was not maintained when biological therapy was further adjusted. Conclusions: Our study indicated that the risks of NTM and MTB infection are not elevated in patients with SpA. Although biological use may potentially increase the risk of MTB infection, it does not lead to a significant increase in incidence rates. Proactive screening for latent tuberculosis and adequate prophylaxis using biologics can effectively manage the risk of NTM and MTB infections.

Cancer risks in patients with ankylosing spondylitis and the effects of biologic agents: a population-based study.

OBJECTIVES: To conduct a population-based analysis of the malignancy risks of patients with ankylosing spondylitis (AS). METHODS: A total of 1,796 patients with AS and 7,184 age- and sex-matched controls (1:4 ratio) were selected from the Korea National Health Insurance Service-National Sample Cohort database. Data of patients diagnosed with AS (code M45) according to the International Classification of Diseases (ICD) 10th edition, between 2002 and 2019, were reviewed. These data were extracted based on the ICD codes assigned to cancer patients. RESULTS: Cancer developed in 168/1,796 patients (9.3%) after the AS diagnosis. After adjusting for confounders, the cancer risk of patients with AS was not significantly increased compared with that of controls (adjusted hazard ratio [HR]: 1.1; 95% confidence interval [CI]: 0.93-1.31). However, the risks for upper gastrointestinal (GI) cancer (adjusted HR: 1.51; 95% CI: 1.07-2.12) and haematologic malignancy (adjusted HR: 2.36; 95% CI: 1.2-4.65) were significantly higher in patients with AS than in controls. There were no significant differences in the risks for other major cancers between patients with AS and controls. Regarding medication for AS, the HR of upper GI cancer was higher in patients with AS compared with controls (adjusted HR: 1.51; 95% CI: 1.00-2.29). CONCLUSION: The overall cancer risks in patients with AS were not significantly different compared with the controls. However, while the effect of non-steroidal anti-inflammatory drugs on upper GI cancer cannot be ruled out, patients with AS exhibited a significant increase in the risk of both upper GI cancer and hematologic malignancy.

Menopausal hormone therapy and risk of seropositive rheumatoid arthritis: A nationwide cohort study in Korea.

OBJECTIVES: This retrospective cohort study aimed to investigate the impact of menopausal hormone therapy (MHT) on the incidence of rheumatoid arthritis (RA) in postmenopausal women and to examine the effects of each specific MHT drug. METHODS: In this Korean population-based cohort study, 452,124 women aged > 40 years who consulted a healthcare provider for menopause were evaluated from January 1, 2011, to December 31, 2014. After propensity score matching, 138,991 pairs were included in the MHT and non-MHT groups. Participants were followed up until December 31, 2020. RA was defined according to the International Classification of Diseases, 10th edition, limited to seropositive RA (M05). RESULTS: RA developed in 567 (0.4 %) of the 138,424 patients in the MHT group. The RA risk in the MHT group was not significantly increased compared with that of controls (hazard ratio [HR] 1.12, 95 % confidence interval [CI] 0.998-1.256). However, MHT use for ≤ 3 years was associated with an increased risk of RA (HR 1.277, 95 % CI 1.127-1.447). When estrogen/progestogen was used, the HR was 1.24 (95 % CI 1.05-1.46), whereas when tibolone was used, the HR was 1.33 (95 % CI 1.13-1.57). CONCLUSION: The use of MHT did not show a significant impact on the development of RA in postmenopausal women. However, a subanalysis that specifically examined the duration of MHT revealed a noteworthy increase in the risk of RA during the initial 3 years of MHT use.