The extrapulmonary dissemination of tuberculosis: A meta-analysis.

Background And Objective: The epidemiology of the forty percent of tuberculosis patients who present with disseminated and/or extrapulmonary disease is in need of further study. Further study of such dissemination using published data from international indices may provide data which assist with control of tuberculosis.

Methods: For each clinical or epidemiologic factor studied, summary odds ratios and corresponding 95% confidence intervals were calculated showing associations between such factors and documented extrapulmonary dissemination of tuberculosis.

Results: Eighteen studies fulfilled criteria for study of the clinical factors and nine for the cytokine studies. Significant factors associated with a greater risk of extrapulmonary dissemination were female gender (summary odds ratio, 1.92 (95% confidence intervals, 1.72-2.13), I-squared 86.9), age under 45 (1.37, 1.18-1.60, 63.7), and as well the absence of smoking, drinking and diabetes but not HIV infection (1.10, 0.91-1.32, 80.5). Among cytokines, the macrophage receptor protein P2X7 was associated most strongly associated with extrapulmonary dissemination of tuberculosis (2.28, 0.88-5.90, 92.9).

Conclusion: Young age, female gender, and the macrophage purinergic receptor protein P2X7 were major factors associated with extrapulmonary dissemination of tuberculosis.