Similar results have been reported by Ddo et al. who found that TB contributes to the decrease in CD4+ T-cell count during TB and/or HIV co-infection.37 Several studies have reported an association of TB with the acceleration of immunodeficiency and increased virus replication in HIV infection.4,6,40,44,45,46 With this in mind, our finding that 75% of co-infected patients had reached the stage of clinical AIDS (CD4 < 200/mm3), compared with 40% of the HIV single-infected patients, is not surprising. The gene discussed is CD4; the disease is tuberculosis.