Association of increased mycobacterium growth inhibitory factor with antituberculous immunity

Cell-mediated immune mechanisms (CMI) were studied in 51 patients of pulmonary tuberculosis to evaluate the role of mycobacterium growth inhibitory factor in prognosis of the infection, before and after the administration of anti-tubercular drugs. Twenty five Mantoux negative individuals who were subsequently bacille Calmette-Guérin (BCG) vaccinated and 25 Mantoux positive, non-tuberculous controls were included in the study. Their clinical assessment was compared with skin sensitivity (Mantoux); lymphocyte transformation (LT) after stimulation with phytohaemagglutinin (PHA) and purified protein derivative (PPD); macrophage migration inhibitory factor (MIF), mycobacteria growth inhibitory factor (Myco IF) and listerial growth inhibitory factor (List IF). The tests were carried out at the beginning of the treatment and at intervals of three months, extending to one year. In the case of Mantoux positive controls, tests were carried out only once. It was found that Mantoux reaction had no correlation with LT, MIF, Myco IF and List IF. Both MIF and Myco IF, were significantly elevated in improving patients, whereas increase in List IF was not significant. An important finding was that Myco IF was at a higher level in improving patients whereas in those not responding to chemotherapy it was low.