Despite advances in diagnosis and treatment, Mycobacterium tuberculosis causes active disease in about 8 million people worldwide annually. The study of the interplay between the host and the pathogen at the site of infection in human TB may contribute to elucidate the pathogenesis of the disease. In this work, using macroarray technology and real-time PCR, we analyzed the modulation of 847 genes encoding immune-inflammatory mediators in BALF samples of patients affected by active pulmonary TB (PTB) and control patients affected by non-TB diseases. The data show that the PTB milieu contains a complex network of gene activation. Different genes with adhesive properties and involved in tissue repair and fibrosis were modulated. In TB patients, we observed the up-regulation of cytokines, including IFN-gamma and IFN-gamma pathway genes, of several apoptotic genes, and of potent transcriptional activators. These findings can contribute to elucidate the mechanisms of MTB pathogenicity in humans. (c) 2006 Elsevier Inc. All rights reserved.