Clinical data pertaining to HIV infected patients with active TB between TB-IGRA positive and TB-IGRA negative groups
184 patients were divided into TB-IGRA positive (n = 133) and TB-IGRA negative (n = 51) groups. The sensitivity of the TB-IGRA was 72.28% among the 184 patients. And clinical characteristics and baseline demographics of the 184 patients between TB-IGRA positive and TB-IGRA negative groups were shown in Table 1. Through analysis of the TB-IGRA positive and negative results, we found that significant difference of CD4 + T cell counts (P ≤ 0.001), CD8 + T cell counts (P = 0.001), CD4 + T cell to CD8 + T cell ratio (P ≤ 0.001), ALB (P = 0.005), ESR (P = 0.047), Lymphocyte counts (P = 0.001) and AST (P = 0.004) between two groups.
Table 1
Clinical data analyses in HIV-infected patients with active TB between positive TB-IGRA and negative TB-IGRA.
| Positive TB-IGRA | Negative TB-IGRA | p-value |
Subjects (n) | 133 | 51 | NA |
Male/female | 119/14 | 45/6 | 0.809 |
Median Age, year | 41(16–86) | 39(23–74) | 0.548 |
Median CD4 + T cell counts, /µL | 108(0-797) | 25(0-700) | < 0.001 |
Median CD8 + T cell counts, /µL | 541(40-2078) | 354(74-1805) | 0.001 |
CD4 + to CD8 + ratio | 0.33(0-3.92) | 0.05(0-0.67) | < 0.001 |
CRP, mg/dl | 46.00(0.40-209.80) | 35.00(0.39–203.00) | 0.532 |
ALB, g/l | 31.6(14.8–50.5) | 27.5(16.3–49.4) | 0.005 |
ESR, mm/h | 62.90 ± 31.26 | 74.73 ± 35.91 | 0.047 |
WBC,10^9/L | 5.54(0-12.21) | 5.66(1.80–33.00) | 0.894 |
Neutrophil counts,10^9/L | 3.81(0.35–61.20) | 4.07(1.12–29.60) | 0.233 |
Lymphocyte counts,10^9/L | 1.02(0-2.99) | 0.68(0.07–3.94) | 0.001 |
RBC,10^12/L | 3.65 ± 0.82 | 3.54 ± 0.79 | 0.391 |
PLT,10^9/L | 242.50(7.90–266.00) | 255.00(3.50–477.00) | 0.628 |
PDW, fl | 11.10(7.60–106.00) | 11.10(7.20–21.60) | 0.936 |
ALT, U/L | 21(4-667) | 22(7-190) | 0.326 |
AST, U/L | 27(8-542) | 40(10–139) | 0.004 |
Patients on HARRT, n (%) | 62 | 22 | 0.671 |
HIV-1 viral load, copies/mL | | | 0.282 |
≥ 100 copies/mL | 82 | 27 |
< 100 copies/mL | 51 | 24 |
TB disease | | | |
Pulmonary | 72 | 25 | 0.104 |
Extrapulmonary | 15 | 12 |
Pulmonary and extrapulmonary | 46 | 14 |
Acid-fast staining method(n) | 38 | 13 | 0.840 |
Pathology(n) | 11 | 2 | 0.520 |
Data are presented as the mean ± standard deviation for normally distributed, medians and interquartile ranges for non-normally distributed. |
Univariate and multivariate analyses of the diagnostic performance of TB-IGRA on HIV infected patients with active TB
Performed by logistic regression analysis, we determined the value of CD4 + T cell counts in the diagnostic performance of TB-IGRA. Via univariate analysis, CD4 + T cell counts, CD8 + T cell counts, CD4 + T cell to CD8 + T cell ratio, ALB, ESR, Lymphocyte counts and AST were included to the logistic regression analysis model. Finally, we found that only CD4 + T cell counts were an independent risk factor for false negative of TB-IGRA (Table 2).
Table 2
Univariate and multivariate analyses of the diagnostic performance of TB-IGRA on HIV infected patients with active tuberculosis.
| Odds ratio | 95% CI | P value |
Univariate analysis | | | |
CD4 + cell count, /µL | 1.006 | 1.003–1.010 | 0.001 |
CD8 + cell count, /µL | 1.002 | 1.001–1.003 | 0.004 |
CD4 + to CD8 + ratio | 40.189 | 3.925-411.482 | 0.002 |
ALB, g/l | 1.070 | 1.018–1.124 | 0.008 |
ESR, mm/h | 0.989 | 0.979–0.999 | 0.031 |
Lymphocyte count, 10^9/L | 2.379 | 1.271–4.452 | 0.007 |
AST, U/L | 0.999 | 0.994–1.004 | 0.671 |
Multivariate analysis | | | |
CD4 + cell count, /µL | 1.006 | 1.003–1.010 | 0.001 |
Data are presented by univariate and multivariate analyses using logistic regression analysis. |
Figure legends. |
Low CD4 + T cell counts in HIV infected patients with active TB were associated with false negative of TB-IGRA
We found that CD4 + T cell counts were significantly lower in TB-IGRA negative group (Fig. 1A, P < 0.001), compared with TB-IGRA positive group. Additionally, we obtained an optimal cut-off value (28.5 cells/µL) of CD4 + T cell counts via ROC analysis. For examining whether declined hierarchy of CD4 + T cell counts were associated with the diagnostic performance of TB-IGRA on HIV infected patients with active TB, patients were divided into three groups based on the levels of CD4 + T cell counts: <20/µL (n = 32), 20–100/µL (n = 70) and > 100/µL (n = 82). And false negative rates of TB-IGRA were 68.75%, 24.29% and 14.63%, respectively, in the three groups (Fig. 1B, P < 0.001). Furthermore, patients were divided into two groups based on the levels of CD4 + T cell counts: ≤50/µL (n = 68) and > 50/µL (n = 116). False negative rates of TB-IGRA of the two groups were 47.05% and 16.38%, (Fig. 1C, P < 0.001). In addition, patients were also divided into four groups based on the levels of CD4 + T cell counts: <20/µL (group 1, n = 32), 20–50/µL (group 2, n = 36) ,51–100/µL (group 3, n = 34) and > 100/µL (group 4, n = 82). The group 1 had the highest false negative rate, compared with other groups (Fig. 1D, P < 0.001). However, there was no significant difference of the false negative rate between group 2 and 3 (P = 0.483), group 3 and 4 (P = 0.623).