Tashiro K, et al. - Researchers investigated the predictive value of plasma hepcidin levels on admission for the treatment outcome of smear-positive pulmonary tuberculosis (PTB) patients without HIV co-infection. This prospective observational study of 35 PTB patients with Mycobacterium tuberculosis (Mtb) -positive sputum smears revealed significantly higher plasma hepcidin levels in PTB patients vs those of healthy subjects. Hepcidin levels on admission were noted to be positively correlated with periods until culture negative. In addition, a negative correlation was evident between hepcidin levels and spot numbers in positive control wells in T-SPOT.TB assays, that allowed exploration of the effect of the peptide on interferon-gamma production in T cells. In Jurkat cells stimulated with phytohaemagglutinin (PHA), an antigen non-specific stimulation, hepcidin dose-dependently reduced IFNG transcription and interferon-gamma production. As per these findings, hepcidin seems to alter immunological reactions against Mtb infection as well as influences the outcome of PTB patients without HIV co-infection.