Background: This cross-sectional study evaluated Apoptotic Protease Activating Factor and cluster of differentiation-4+ (CD4+) T-cell counts in patients infected with Mycobacterium tuberculosis in Bauchi, Nigeria.
Methods: This involved 180 blood samples from 90 tuberculosis (TB)-infected patients and 90 of their close contacts at home or attending Federal Medical Center Azare and Infectious Disease Hospital Bayara, Bauchi, Nigeria. The blood samples were analyzed for Apoptotic Protease Activating Factor (Apaf-1) expression using ELISA and CD4+ T cells using cyflow counter. Structured questionnaires were also used to collect the sociodemographic and clinical data of the study participants.
Results: Eighty-six of the TB-infected patients had pulmonary TB (PTB), two had spine TB, and two had pleural TB. No statistically significant difference was recorded in CD4+ T-cell counts (P = 0.2935) between participants with PTB (mean ± standard deviation [SD]: 680.4 ± 235 cells/mm3) and those with extra-PTB (mean ± SD: 553.0 ± 130.5 cells/mm3). Similarly, there was no significant difference in Apaf-1 concentration (P = 0.1432) between participants with PTB (mean ± standard error of the mean [SEM]: 320.3 ± 35.4 pg/ml), and participants with extra-PTB (mean ± SEM: 143.7 ± 7.8 pg/ml). No significant difference was recorded in CD4+ T-cell counts (P = 0.4299) between the participants on treatment (mean ± SD: 758.6 ± 358.6 cells/mm3) and those who are treatment naïve (mean ± SD: 637.7 ± 208.4 cells/mm3). Similarly, there was no significant difference in Apaf-1 concentration (P = 0.6829) between the study participants on treatment (mean ± SEM: 336.3 ± 34.7 pg/ml) and those who are not on treatment (mean ± SEM: 381.2 ± 176.8 pg/ml). The CD4+ T-cells count was significantly higher in the controls (866.7 ± 288.4 cells/mm3) compared to the TB (675.0 ± 232.7 cells/mm3) patients (P < 0.0001). However, there was no significant difference in Apaf-1 expression between the control (312.4 ± 34.6 pg/ml) and the TB patients (329.1 ± 44.0 pg/ml) (P = 0.7658).
Conclusion: Findings from this study showed a lower T-cell immune function during TB infection. However, Apaf-1 has no relevance on TB progression and control.
Keywords: Apaf-1; cellular immunity; cluster of differentiation-4+ T-cells; tuberculosis.