Methods: We performed an unmatched case control study among patients with NTM diseases who were diagnosed and treated at Siriraj Hospital, Bangkok, Thailand. Anti-IFN autoantibody was assayed by enzyme-linked immunosorbent assay (ELISA) method. Cases were patients with NTM diseases and detectable anti IFN- γ autoantibody. Controls were randomly selected from those with undetectable anti IFN- γ autoantibody. Data collection included demographic data, clinical presentations, laboratory results, and suspected risk factors such as HLA analysis. Univariate and multivariate analyses were performed to identify independent risk factors for this syndrome.
Results: 70 cases (mean age 50 ± 11 years) and 72 controls (mean age 58 ± 19 years) were enrolled into the study. Mycobacterial abscessus was the most common NTM pathogen found in both groups (72.9% in cases and 41.7% in controls respectively). However, disseminated NTM disease was significantly more common in cases (92.9%) than in the controls (13.9%, p<0.001). Binary logistic regression analysis showed that comorbidities lead to immunosuppression, such as HIV infection or diabetes mellitus (adjusted OR 0.01, 95%CI 0.00-0.11), disseminated NTM disease (adjusted OR 334.14, 95%CI 27.11-4117.36) and presence of HLA DRB1*15/16:02 or DQB1*05:01/02 (adjusted OR 18.87, 95%CI 1.63-218.76) were independent factors associated with this syndrome.
Conclusion: Patients with NTM disease associated with anti IFN- γ autoantibody are almost always previously healthy and HIV negative. Most of these patients presented with disseminated NTM disease with generalized lymphadenitis and often with reactive skin lesions. Risk factors for developing anti IFN- γ autoantibody are HLA-DRB1 and DQB1 alleles, and presentation with disseminated NTM diseases, especially in patients without immunodeficiency. Further studies are needed to better understand these associations and to improve the treatment outcome.
Y. Suputtamongkol, None