Cocaine and metabolites by LC-MS/MS

Cocaine use associated gut permeability and microbial translocation in people living with HIV in the Miami Adult Study on HIV (MASH) cohort

OBJECTIVE

Determine if cocaine use impacts gut permeability, promotes microbial translocation and immune activation in people living with HIV (PLWH) using effective antiretroviral therapy (ART).

METHODS

Cross-sectional analysis of 100 PLWH (ART ≥6 months, HIV-RNA <200 copies/mL) from the Miami Adult Studies on HIV (MASH) cohort. Cocaine use was assessed by self-report, urine screen, and blood benzoylecgonine (BE). Blood samples were collected to assess gut permeability (intestinal fatty acid-binding protein, I-FABP), microbial translocation (lipopolysaccharide, LPS), immune activation (sCD14, sCD27, and sCD163) and markers of inflammation (hs-CRP, TNF-α and IL-6). Multiple linear regression models were used to analyze the relationships of cocaine use.

RESULTS

A total of 37 cocaine users and 63 cocaine non-users were evaluated. Cocaine users had higher levels of I-FABP (7.92±0.35 vs. 7.69±0.56 pg/mL, P = 0.029) and LPS (0.76±0.24 vs. 0.54±0.27 EU/mL, P<0.001) than cocaine non-users. Cocaine use was also associated with the levels of LPS (P<0.001), I-FABP (P = 0.033), and sCD163 (P = 0.010) after adjusting for covariates. Cocaine users had 5.15 times higher odds to exhibit higher LPS levels than non-users (OR: 5.15 95% CI: 1.89-13.9; P<0.001). Blood levels of BE were directly correlated with LPS (rho = 0.276, P = 0.028), sCD14 (rho = 0.274, P = 0.031), and sCD163 (rho = 0.250, P = 0.049).

CONCLUSIONS

Cocaine use was associated with markers of gut permeability, microbial translocation, and immune activation in virally suppressed PLWH. Mitigation of cocaine use may prevent further gastrointestinal damage and immune activation in PLWH.

Cocaethylene, simultaneous alcohol and cocaine use, and liver fibrosis in people living with and without HIV

BACKGROUND

The simultaneous consumption of cocaine and alcohol results in the production of cocaethylene (CE) in the liver, a highly toxic metabolite. Prior research suggests that cocaine use contributes to liver disease and its concomitant use with alcohol may increase its hepatotoxicity, but studies in humans are lacking. We evaluated the role of cocaine, its simultaneous use with alcohol, and CE on liver fibrosis.

METHODS

We performed a cross-sectional analysis of the Miami Adult Studies on HIV (MASH) cohort. Cocaine use was determined via self-report, urine screen, and blood metabolites, using liquid chromatography with tandem mass spectrometry. Hazardous drinking was determined with the AUDIT-C and liver fibrosis with the Fibrosis-4 Index (FIB-4).

RESULTS

Out of 649 participants included in this analysis, 281 (43.3%) used cocaine; of those, 78 (27.8%) had CE in blood. Cocaine users with CE had higher concentrations of cocaine metabolites in blood and were more likely to drink hazardously than cocaine users without CE and cocaine non-users. Overall, cocaine use was associated with liver fibrosis. CE in blood was associated with 3.17 (95% CI: 1.61, 6.23; p = 0.0008) times the odds of liver fibrosis compared to cocaine non-users, adjusting for covariates including HIV and HCV infection. The effect of CE on liver fibrosis was significantly greater than that of cocaine or alcohol alone.

CONCLUSIONS

CE is a reliable marker of simultaneous use of cocaine and alcohol that may help identify individuals at risk of liver disease and aid in the prevention of its development or progression.

Liquid chromatography–tandem mass spectrometry for clinical diagnostics

Mass spectrometry is a powerful analytical tool used for the analysis of a wide range of substances and matrices; it is increasingly utilized for clinical applications in laboratory medicine. This Primer includes an overview of basic mass spectrometry concepts, focusing primarily on tandem mass spectrometry. We discuss experimental considerations and quality management, and provide an overview of some key applications in the clinic. Lastly, the Primer discusses significant challenges for implementation of mass spectrometry in clinical laboratories and provides an outlook of where there are emerging clinical applications for this technology.

Tandem mass spectrometry is increasingly utilized for clinical applications in laboratory medicine. In this Primer, Thomas et al. discuss experimental considerations and quality management for implementing clinical tandem mass spectrometry in the clinic with an overview of some key applications.

Unrecorded alcohol in Rio de Janeiro: assessing its misusers through Respondent Driven Sampling

BACKGROUND

Around 20-30% of alcohol use in low and middle-income countries is estimated to come from unrecorded sources, but little is known about the characteristics of its consumers. The aim of this study was to obtain information about users of unrecorded alcohol and describe factors associated with its frequent use.

METHOD

A cross-sectional study, using Respondent Driven Sampling (RDS), was conducted in Rio de Janeiro, Brazil in 2010. Individuals aged 18-65 who reported binge drinking in the last 12 months were recruited to participate in a structured interview. Three sources of unrecorded alcohol use were assessed: home-made/unrecorded; perfumes/lotions; and "medicinal" products (compounds made of herbs and local spirits).

RESULTS

343 individuals were recruited and 303 were interviewed. The sample comprised mostly of men (n=256) from low socioeconomic strata, with a mean age of 38.8 (±12). Most individuals (71.8%) reported to have used more than one variety of unrecorded alcohol, which was found to be associated with: being older than 31 (OR 2.21; CI 95% 1.05-4.80), an AUDIT score >20 (OR 11.21; CI 95% 4.56-30.96), having used crack/cocaine (OR 2.29; CI 95% 1.02-5.21), and having received treatment for alcohol addiction in the last 12 months (OR 3.64; CI 95% 1.25-13.49).

CONCLUSION

Most unrecorded alcohol users were disadvantaged polysubstance users. Assessing unrecorded alcohol use has important clinical implications and should be screened for among crack/powder cocaine and alcohol-dependent patients.