[Immunohistochemical localization of matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) in tuberculous pleuritis]

Host gene-encoded severe lung TB: from genes to the potential pathways

We are reporting that the two-locus genotype -2518 macrophage chemoattractant protein (MCP)-1 GG and -1607 matrix metalloproteinase (MMP)-1 2G/2G promotes the expression of hyperinflammation in response to Mycobacterium tuberculosis infection, inducing extensive tissue damage and severe tuberculosis (TB) disease. Carriers of this two-locus genotype have a 13-fold higher chance of developing severe disease and 6.5-fold higher chance of developing permanent lesions, and a 3.864-fold higher chance of delayed response to first-line standardized treatment than carriers of any other relevant combination of genotypes at those two loci. Thus, these persons have an increased likelihood of poor health-related quality of life and of transmitting M. tuberculosis to other members of the community. In addition, through the analysis of human lung tissues, serum/plasma and in vitro experiments, including in vitro infections of THP-1 cells with M. tuberculosis and microarray analysis, we determined that this hyperinflammation state is potentially driven by the MCP-1/MMP-1/PAR-1 pathway. Hence, we are providing markers for the identification of TB cases that may develop severe pulmonary disease and delayed response to treatment, and are providing the basis for development of novel host-targeted clinical interventions to ameliorate the severity of pulmonary TB.

[Pulmonary and pleural tuberculosis in the elderly]

With the increase of the proportion of the elderly in the total population more cases of pulmonary and extrapulmonary tuberculosis (TB) are observed in this age group as well. Symptoms of TB are unspecific, often less apparent in the elderly, and may therefore cause a delay in the diagnostic process. A history of TB and comorbidities are more common in elder as compared to younger TB patients. The tuberculin skin test is less frequently positive. The interferon-gamma-release assay is complementary and together with clinical, radiologic, and bacteriologic test results helpful for the diagnosis or the exclusion of an active or latent TB infection. Medical treatment of TB in the elderly follows the established guidelines in the same way as for younger patients. The likelihood of drug-induced side effects and interactions with concomitant medications, however, is increased. Comorbidity and age-related immunosuppression may lead to a delay in the healing process. Higher age, comorbidity, and immunosuppression are predictors of an increased TB mortality. Even in a low-incidence country like Germany, TB should be recognized as an explanation for clinical symptoms particularly in the elderly patient group in order to allow an early diagnosis and therapy and thus a reduction of mortality and prevention of a further spread of this disease.