LAUSR

Background: Anti-interferon (IFN) gamma antibody was a rare autoantibody which mainly been reported in Asia. It interferes the interferon pathway and eradication of intracellular pathogens, such as Salmonella or Mycobacteria. This rare disease should be raised for more awareness. Objectives: To analyze clinical presentations of the patients with anti-interferon (IFN) gamma antibody. Methods: We checked anti-IFN gamma antibody when patient fulfilled multiple NTM infection (especially bone marrow and lymph nodes). There are 6 cases of non-tuberculosis mycobacteria (NTM) infection accompanying with anti-IFN gamma antibody in our hospital from 2015 to 2019 of hospitalist ward, and the antibody titer is recorded. Results: Among these cases, patients had initial presentations of fever (100%), elevated CRP and ESR (100%), lymphadenopathy (67%), body weight loss (50%), and elevated LDH (50%). All the 6 cases had negative results of TB-PCR test, but 1 had positive result of interferon gamma release assay (IGRA, 17%). NTM was identified from lymph node biopsy (50%), sputum (33%), skin (33%), and bone marrow (33%). Different NTM was identified, including Mycobacterium abscessus, Mycobacterium fortuitum group complex, Mycobacterium kanasii, and Mycobacterium avium complex. Prolonged antibiotics treatment was used, but all patients had recurrent or persisted NTM infection under medications. 4 cases had different NTM strain after 1 year of treatment from the initial involved organ. One case had an episode of Salmonella bacteremia with septic shock. Another case had positive result of ANA, and other cases had negative auto-antibodies. Conclusion: Careful history taking and physical examinations are crucial in diagnosis this acquired immunodeficiency disease. This rare but unique disease should be taken into consideration. Disclosure of Interests: None declared