Određivanje interferona gama ex vivo u zdravstvenih radnika

Detection and follow-up the blood test determining interferon-gamma (IFN-γ) released from effector T-lymphocytes (interferon-gamma release assay, IGRA) upon stimulation with M. tuberculosis specific peptides should be performed in subjects at an increased risk of M. tuberculosis infection such as health care workers (HCW) in chest hospital and immunocompromised subjects. Two cases of HCW with type 1 diabetes mellitus (T1DM) and positive anti-thyroglobulin (anti-Tg) autoantibodies, respectively, are presented. Case 1: a 46 year-old female HCW who has been having T1DM for 20 years underwent routine screening for Latent tuberculosis infection (LTBI). She was not acutely ill, she had normal body temperature, was eupneic and lung auscultation show normal breathing. Tuberculin skin test (TST) was negative and IGRA was positive (4.7 kIU/L). Positive IGRA indicated the LTBI, while TST result was false negative. Antituberculosis prophilaxis was not used. Case 2: a 57 year-old clinically healthy female was included in an annual screeding for LTBI. Initial testing showed positive TST and IGRA (5.2 kIU/L) and elevated levels of anti-Tg (86.4 kIU/L). She was free from acute disease, afebrile, eupneic, with normal breath sounds on auscultation. One year later IGRA was still positive. Antituberculosis prophilaxis was not used. Although isoniazid prophylaxis was not used in these subjects, tuberculosis did not develop during the 4-year follow-up period.