CD4 and tuberculosis: The researchers found 11 studies that compared tuberculosis incidence by ART status in HIV-infected adults over periods longer than six months on average in developing countries and undertook meta-analyses of these studies based on four categories of CD4 count at ART initiation (less than 200 cells/μl, 200–350 cells/μl, greater than 350 cells/μl, and any CD4 count).