Age Association Analysis between Tricarboxylic Acid Metabolites and Neurocognitive Impairment in Persons Living with HIV
Authors: Azzam Sausan , Hileman Corrilynn , Schlatzer Daniela , Chance Mark R , Tassiopoulos Katherine , Kalayjian Robert 
Published: June 2021

Objective

Inflammation may contribute to neurocognitive impairment (NCI) in people with HIV (PWH). Lipopolysaccharide‐mediated macrophage activation induces a shift from oxidative phosphorylation to glycolysis in‐vitro with accumulation of the tricarboxylic acid (TCA) metabolites succinate (SA) and citrate (CA). These metabolites engage diverse cellular inflammatory pathways and may indicate mitochondrial dysfunction. In this study, we developed and optimized an LC‐MS metabolomic method to allow the simultaneous detection and analysis of plasma SA and CA metabolites in in people with HIV.

Methods

Generalized estimating equations were used in a random sample of older PWH from the prospective, multicenter HAILO cohort. Plasma sample was mixed with methanol‐acetonitrile‐water (5:3:1) and 0.1mg/mL internal standard (ISTD, D4‐citric acid). The mixture was vortexed for 30 minutes and centrifuged at 10,000g for 10 minutes. The supernatants were dried, reconstituted in 0.2% formic acid/0.1mg/ml ISTD. Samples were analyzed using Kinetex ‐ C18 column coupled to an Agilent 6540 Q‐TOF LC‐MS. Metabolites identification was achieved based on retention time and product ions. Calibration curves were obtained by using SA and CA authentic standards spiked into 0.2% formic acid/0.1mg/mL ISTD. Using Agilent MassHunter Qualitative B.07 Software, the ratio of analyte and ISTD peak area was plotted against the corresponding concentration to obtain calibration curves. The peak area and the concentration of each analyte were determined using the peak area ratio. Neurocognition was assessed every 48 wks, where NCI was defined as ≥1 z‐scores ≥2 SD below 0 or ≥2 z‐scores ≥1 SD below 0 on Trailmaking A and B and the Wechsler Adult Intelligence Scale‐Revised Digit Symbol tests.

Results

200 participants were followed a mean ±SD of 160 ±51 wks with a mean of 4 ±1.1 assessments. The mean age was 51 ±7 yrs, 84% were men, 49% were white non‐Hispanic and 59% were current or past smokers. HIV‐1 RNA levels were <400 copies/ml in 97% and the mean nadir and baseline CD4 counts were 234 and 664 cells/mm3, respectively. The mean education was 14 ±4 yrs and NCI was detected at entry in 53 participants (27%). Age modified associations between each metabolite and NCI (P=0.01 for interactions by age with each metabolite). A 1 SD increase of SA or CA levels associated with a 2.2 [95%CI 1.1, 4.3] or a 1.9 [1.3, 2.8] greater odds of NCI, respectively, in the oldest age‐tertile but not in younger age‐groups (Table).

Conclusion

Associations between plasma TCA metabolite levels and NCI were evident among older PWH, possibly implicating inflammatory effects on neurocognition that associate with these metabolites or mitochondrial dysfunction and warrant further study.

Support or Funding Information

NHLBI (K23HL116209) and NIAD (P30 AI036219)

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.