Association between PFAA and metabolite concentrations before ICI therapy and OS
| PFAA/metabolite (μM) | Mean (SD) | Cox hazard model | ||
| HR | 95% CI | P value | ||
| Glutamic acid | 50.5 (22.2) | 1.03 | 0.71 to 1.45 | 0.863 |
| Serine | 101.6 (27.4) | 0.72 | 0.50 to 1.03 | 0.075 |
| Asparagine | 41.9 (10.8) | 0.73 | 0.47 to 1.06 | 0.107 |
| Glycine | 207.4 (64.5) | 0.69 | 0.45 to 1.00 | 0.049 |
| Glutamine | 543.4 (101.6) | 0.77 | 0.51 to 1.16 | 0.213 |
| Histidine | 65.0 (23.0) | 0.52 | 0.30 to 0.86 | 0.009 |
| Threonine | 107.4 (41.8) | 0.58 | 0.34 to 0.91 | 0.015 |
| Alanine | 305.2 (110.6) | 0.60 | 0.41 to 0.87 | 0.006 |
| Citrulline | 30.4 (13.1) | 0.61 | 0.39 to 0.92 | 0.018 |
| Arginine | 74.1 (20.3) | 0.42 | 0.27 to 0.64 | <0.001 |
| Proline | 151.3 (63.3) | 0.80 | 0.53 to 1.11 | 0.199 |
| α-Amino butyric acid | 17.5 (6.0) | 0.99 | 0.70 to 1.39 | 0.977 |
| Tyrosine | 63.5 (17.4) | 0.79 | 0.52 to 1.14 | 0.234 |
| Valine | 210.5 (63.7) | 0.78 | 0.52 to 1.12 | 0.193 |
| Methionine | 22.1 (7.5) | 0.75 | 0.46 to 1.12 | 0.183 |
| Ornithine | 64.9 (13.4) | 0.72 | 0.46 to 1.10 | 0.126 |
| Lysine | 175.7 (49.1) | 0.70 | 0.47 to 1.03 | 0.069 |
| Isoleucine | 69.2 (29.7) | 0.90 | 0.56 to 1.22 | 0.566 |
| Leucine | 120.8 (47.7) | 0.87 | 0.55 to 1.22 | 0.471 |
| Phenylalanine | 62.1 (13.3) | 1.23 | 0.83 to 1.82 | 0.294 |
| Tryptophan | 46.8 (17.8) | 0.53 | 0.34 to 0.83 | 0.005 |
| 3h-kynurenine | 0.069 (0.050) | 1.85 | 1.27 to 2.60 | 0.002 |
| 3h-anthranilic acid | 0.047 (0.036) | 1.37 | 0.86 to 1.96 | 0.166 |
| 5h-indol-3-acetic acid | 0.070 (0.062) | 1.02 | 0.68 to 1.33 | 0.923 |
| 5h-tryptophan | 0.005 (0.009) | 1.38 | 0.99 to 1.74 | 0.054 |
| Anthranilic acid | 0.019 (0.016) | 1.47 | 1.13 to 1.82 | 0.007 |
| Indol-3-acetic acid | 1.996 (1.771) | 0.81 | 0.51 to 1.12 | 0.236 |
| Indol-3-lactic acid | 0.862 (0.551) | 0.96 | 0.67 to 1.28 | 0.810 |
| Kynurenic acid | 0.049 (0.027) | 1.22 | 0.83 to 1.73 | 0.293 |
| Kynurenine | 2.448 (0.716) | 1.37 | 0.96 to 1.95 | 0.083 |
| Picolinic acid | 0.054 (0.033) | 1.18 | 0.82 to 1.63 | 0.358 |
| Quinolinic acid | 0.730 (0.515) | 1.34 | 1.00 to 1.69 | 0.049 |
| Serotonin | 0.159 (0.152) | 1.09 | 0.70 to 1.55 | 0.680 |
| Xanthurenic acid | 0.011 (0.012) | 0.91 | 0.60 to 1.29 | 0.572 |
| Neopterin | 0.010 (0.009) | 1.50 | 1.10 to 1.92 | 0.014 |
| N′-formyl-kynurenine | 0.018 (0.014) | 0.82 | 0.46 to 1.14 | 0.295 |
The concentrations of PFAAs and metabolites are shown as mean and SD values.
Univariate analysis of PFAAs and metabolites before ICI therapy was conducted using the Cox proportional hazard model for OS. HR, 95% CI and P values are shown.
ICI, immune checkpoint inhibitor; OS, overall survival; PFAA, plasma-free amino acid.