Treatment outcome of latent tuberculosis infection in persons with fibrotic pulmonary lesions

Objective　This study aimed to evaluate the treatment outcome of latent tuberculosis infection (LTBI) in persons with fibrotic pulmonary lesions, treated with isoniazid (INH) or rifampicin (RFP) in Nishinari Ward, Osaka City.Methods　As part of a tuberculosis screening program by chest X-ray (CXR), we selected persons who met the following four criteria for initiation of LTBI treatment:①Anti-tuberculosis treatment has not been performed for more than one month in the past.②CXR shows fibrotic pulmonary lesions.③Fibrotic pulmonary lesions with CXR have not changed for more than one year.④QuantiFERON TB Gold-in-tube (QFT) shows positive values (≥0.35 IU/mL).　Before treatment, the blood samples were within the standard values for aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin, and serum creatinine. Treatment with INH was stopped when AST or ALT levels were elevated to more than 150 IU/L, or symptoms of liver dysfunction appeared even when AST or ALT levels were less than 150 IU/L. After liver dysfunction improved, treatment with RFP was started.　Treatment completion was defined as being dispensed with INH for ≥180 days or RFP for ≥120 days.Results　The 27 participants were all male and their age was 68.4±6.6 years. Of the 27 participants, 14 (51.9%) completed treatment with INH. Of the remaining 13 persons, nine (69.2%) stopped treatment with INH because of liver dysfunction. Nine restarted RFP treatment and all participants completed the treatment without interruption by liver dysfunction. In total, 23 (85.2%) completed the treatment.Conclusion　LTBI treatment with INH in persons with fibrotic pulmonary lesions in the area where people in financial need live was stopped because of liver dysfunction; however, changes from INH to RFP could improve treatment outcomes.