Table 6.
Concurrent predictors associated with citrulline, kynurenine, and tryptophan concentrations and the KT ratio at baseline in young Laotian children: immune biomarkers
| Variables | N | Citrulline (µmol/L)§ | Kynurenine (µmol/L) | Tryptophan (µmol/L) | KT (ratio × 1,000) |
|---|---|---|---|---|---|
| Leukocytes in peripheral blood (cells/µL) | |||||
| Neutrophils | 324 | −0.74 (−1.86, 0.39) | −0.11 (−0.28, 0.07) | 0.07 (−2.77, 2.91) | −1.96 (−4.56, 0.64) |
| Eosinophils | 324 | 0.28 (−0.1, 0.66) | −0.01 (−0.07, 0.05) | 0.49 (−0.47, 1.45) | −0.44 (−1.32, 0.44) |
| Basophils‖ | 157 | 0.01 (−0.13, 0.16) | 0.01 (−0.13, 0.16) | 0.33 (−1.89, 2.54) | −0.19 (−2.31, 1.94) |
| Lymphocytes | 324 | 0.05 (−0.19, 0.28) | 0.03 (−0.01, 0.06) | 0.89 (0.32, 1.46)† | −0.17 (−0.7, 0.37) |
| Monocytes | 323 | −0.66 (−1.37, 0.05) | −0.06 (−0.17, 0.05) | −0.9 (−2.68, 0.88) | −0.39 (−2.03, 1.24) |
| T-cell subsets in peripheral blood (cells/mL) | |||||
| CD4 total | 271 | 1.00 (0.00, 2.01)* | −0.15 (−0.31, 0.00) | 4.04 (1.53, 6.55)† | −4.72 (−6.97, −2.48)‡ |
| CD4 Treg total | 271 | 8.93 (−2.87, 20.73) | −1.47 (−3.27, 0.33) | 40.16 (10.81, 69.52)† | −48.71 (75.17, −22.26)‡ |
| CD8 total | 271 | 1.01 (−1.38, 3.40) | −0.03 (−0.40, 0.34) | 8.41 (2.43, 14.38)† | −5.56 (−11.02, −0.10)* |
| CD4 memory | 271 | 5.30 (−0.64, 11.23) | −0.71 (−1.63, 0.20) | 10.32 (−4.72, 25.36) | −16.72 (−30.28, −3.16)* |
| CD8 memory | 271 | −2.31 (−10.82, 6.2) | 1.61 (0.31, 2.90)* | −1.57 (−23.11, 19.96) | 27.94 (8.67, 47.2) † |
| Cytokines produced by cultured whole blood cells with LPS stimulation (negative control cultures) (pg/mL) | |||||
| IL-10 | 264 | 0.17 (−0.25, 0.58) | 0.01 (−0.05, 0.08) | −1.18 (−2.23, −0.14)* | 1.04 (0.09, 1.99)* |
| IL-6 | 264 | 0.00 (−0.28, 0.28) | 0.01 (−0.03, 0.06) | −0.78 (−1.48, −0.08)* | 0.65 (0.01, 1.29)* |
| IL-1β | 264 | 0.03 (−0.32, 0.37) | 0.02 (−0.03, 0.08) | −0.72 (−1.6, 0.15) | 0.77 (−0.02, 1.57) |
| TNFα | 264 | 0.10 (−0.35, 0.55) | 0.01 (−0.06, 0.08) | −0.71 (−1.87, 0.44) | 0.59 (−0.46, 1.64) |
| Cytokines produced by cultured whole blood cells with T-cell stimulation (negative control cultures) (pg/mL) | |||||
| IFN-γ | 267 | −0.17 (−0.44, 0.10) | 0.03 (−0.02, 0.07) | −0.02 (−0.71, 0.68) | 0.48 (−0.15, 1.11) |
| IL-2 | 267 | 0.21 (−0.04, 0.46) | −0.01 (−0.05, 0.03) | 0.15 (−0.49, 0.79) | −0.26 (−0.84, 0.32) |
| IL-13 | 267 | 0.08 (−0.22, 0.38) | −0.05 (−0.10, −0.01)* | −0.33 (−1.09, 0.42) | −0.49 (−1.18, 0.2) |
| IL-17 | 267 | −0.10 (−0.44, 0.23) | 0.00 (−0.06, 0.05) | −0.66 (−1.52, 0.2) | 0.36 (−0.43, 1.15) |
CD = cluster of differentiation; IFN = interferon; IL = interleukin; KT = kynurenine:tryptophan; TNF = tumor necrosis factor; Treg = regulatory T cells. *P < 0.05, †P < 0.01, ‡P < 0.001.
§ Models adjusted for age at enrollment and district. Values represent beta coefficient and 95% CI from linear regression models. For continuous predictors, this represents the change in outcome corresponding to a one unit increase in the predictor.
‖ Children with basophils below the limit of detection are not included in this analysis (basophil concentration is included as a continuous variable). When basophil concentration was treated as a categorical variable (above or below the limit of detection), the results were consistent.