P302 Tryptophan metabolites are not associated with depressive symptoms in HIV

Abstract

<h3>Background</h3> This study aims to determine the relationship amongst tryptophan metabolites, inflammation markers, and depression in people with HIV (PWH). <h3>Methods</h3> This is a 12-month prospective study of chronically depressed (PHQ9≥10 for 2+ years) PWH on antiretroviral therapy (ART) to evaluate the effect of baseline plasma tryptophan (TRP), kynurenine (KYN), kynurenic acid (KA) and quinolinic acid (QA) and inflammation markers (hsCRP, IL6, sTNF-RI and -RII) quantified by LC/MS/MS and ELISA, respectively, on depressive symptoms over time. Age/sex/CD4-count matched PWH with PHQ9&lt;5 underwent a single visit for cross-sectional comparisons. Multivariable linear and logistic regression and linear mixed effects models were utilized. <h3>Results</h3> 95 adults were enrolled (48 depressed; 47 control). Median age was 46; 63% men, 35% woman; 2% transgender MTF; 58% black; 36% white; and 6% Hispanic regardless of race. Depressed were less likely to have completed high school/GED (70 vs 91%), were more sedentary (67 vs 18% &lt;10hrs exercise/week) and more likely to smoke (75 vs 19%) (all p&lt;0.03). Baseline CD4 count (median 673 cells/mm³), proportion with HIV-1 RNA&lt;20 (77%) and HIV duration were similar (9yrs). Baseline sTNF-RI and -RII were positively correlated KYN, KYN:TRP, QA and QA:KA (all p&lt;0.01). hsCRP and IL6 were positively correlated with QA and QA:KA. After adjusting for demographics and factors different between groups, depressed participants had higher inflammatory markers with the exception of IL6 and slightly lower tryptophan metabolites than controls (differences not statistically significant). Higher baseline tryptophan, but not other metabolites nor inflammation markers, was associated with higher PHQ over time (p=0.04). Last, none of the markers were associated with depressive symptom remission at 6 or 12 months. <h3>Conclusion</h3> In the context of ART-treated HIV, tryptophan metabolites and inflammation markers were strongly correlated, but neither appear to be related to symptoms of depression.