Table 3.
Association between monocyte chemoattractant protein-1 (MCP-1) and kynurenine metabolites and cytokines in cerebrospinal fluid (CSF)
| CSF-markers | Within-pair differences—MZ pairs (n = 5) | Within-pair differences—DZ pairs (n = 5) | ||
|---|---|---|---|---|
| MCP-1 | MCP-1 | |||
| Reg. Coef. (95% CI) | p value | Reg. Coef. (95% CI) | p value | |
| Tryptophan (TRP) | − 0.52 (− 2.32, 1.28) | 0.51 | 0.51 (0.24, 0.79) | 0.005 |
| Kynurenic acid (KYNA) | 1.03 (0.64, 1.42) | 0.001* | 0.59 (0.33, 0.85) | 0.002* |
| Quinolinic acid (QUIN) | 0.11 (− 0.84, 1.05) | 0.79 | 0.02 (− 3.92, 3.95) | 0.99 |
| Interleukin 6 (IL 6) | 0.14 (− 0.04, 0.32) | 0.12 | 1.38 (− 4.48, 7.24) | 0.57 |
| Interleukin 8 (IL-8) | − 0.49 (− 0.94, − 0.04) | 0.037 | − 2.06 (− 5.47, 1.34) | 0.18 |
| Tumor Necrosis Factor alpha (TNF-α) | − 0.48 (− 0.74, − 0.22) | 0.004 | − 1.25 (− 3.65, 1.16) | 0.24 |
Results from the conditional linear regression analysis of the differences within the complete twin pairs
All variables were standardized [mean = 0, standard deviation (SD) = 1]. Conditional linear regression was used for analysis, with cluster-robust sandwich estimator for standard errors. Results presented as the regression coefficient (Reg. Coef.) with 95% confidence intervals (CI). We interpreted that a higher coefficient in the MZ pairs than in the DZ pairs, was an effect from unique environmental factors, and a higher coefficient in the DZ pairs than in the MZ pairs as an effect from genetic factors
*Indicates that the p values are significant after Bonferroni correction (p value < 0.003)