[The influence of chronic viral infections on tuberculosis].

The influence of chronic viral infections (CVI) on tuberculosis (TB) was investigated in 117 patients with mix infection (HHV-2 - human herpes virus-2) and TB; 6 patients with mix infection (CMV - cytomegalovirus) and TB; 22 patients with mix infection (individuals with chronic hepatitis C virus (HCV) infection and TB. The control group was composed of 33 TB patients without CVI. Increased rates of atypical tuberculosis, reactivation of latent tuberculosis have been reported among patients with mix infection - TB and HHV-2. Patients with mix infection (TB and HHV-2) had deficiency in natural killer (NK) cell cytotoxic activity. Tendency in these changes was shown in case of TB and CMV. In all cases there were no significant changes in CD56+ cell number. These studies demonstrate that NK cell cytotoxic activity, not NK (CD56+) cell number, plays a key role in the development of the suppression of immune responses in patients with CVI and TB.