Pharmacogenetics of weight gain following switch from efavirenz- to integrase inhibitor-containing regimens

BACKGROUND

Excessive weight gain affects some persons with HIV after switching to integrase strand transfer inhibitor (INSTI)-containing antiretroviral therapy (ART). We studied associations between CYP2B6 genotype and weight gain after ART switch among ACTG A5001 and A5322 participants.

METHODS

Eligible participants switched from efavirenz- to INSTI-containing ART, had genotype data, and had weight data at least once from 4 weeks to 2 years post-switch. Multivariable linear mixed effects models adjusted for race/ethnicity, CD4, age, BMI and INSTI type assessed relationships between CYP2B6 genotype and estimated differences in weight change.

RESULTS

A total of 159 eligible participants switched ART from 2007 to 2019, of whom 138 had plasma HIV-1 RNA < 200 copies/mL (65 CYP2B6 normal, 56 intermediate, 17 poor metabolizers). Among participants with switch HIV-1 RNA < 200 copies/mL, weight increased in all 3 CYP2B6 groups. The rate of weight gain was greater in CYP2B6 poor than in CYP2B6 normal metabolizers overall, and within 9 subgroups (male, female, White, Black, Hispanic, dolutegravir, elvitegravir, raltegravir, and TDF in the pre-switch regimen); only in Hispanic and elvitegravir subgroups were these associations statistically significant ( P  < 0.05). Compared to normal metabolizers, CYP2B6 intermediate status was not consistently associated with weight gain.

CONCLUSION

CYP2B6 poor metabolizer genotype was associated with greater weight gain after switch from efavirenz- to INSTI-containing ART, but results were inconsistent. Weight gain in this setting is likely complex and multifactorial.

Abstract P187: Qualitative Description of Physical Activity Perceptions and Experiences in Older Adults With HIV

Background: The benefits of physical activity, and specifically exercise, among older adults are well known. Yet, globally there is concern regarding limited engagement in physical activity and rising cases of obesity and frailty among older people with HIV (PWH). We explored the experiences and perceptions of PWH enrolled in the High-intensity Exercise study to Attenuate Limitations and Train Habits (HEALTH) study.

Methods: Thirty-two participants were enrolled between February 2021 and August 2022. We conducted in-depth interviews among sedentary, older PWH in the ongoing HEALTH (NCT04550676) study. A semi-structured interview guide was informed by the two minds theory, which frames behavior change as an intention-behavior gap between two neurocognitive systems. The intuitive system, described as immediate or first reactions, optimizes behavior based on its expected consequences at the moment, whereas the narrative system produces beliefs about possible behavior in the future sequentially and thoughtfully. Interviews explored general exercise perceptions, self-efficacy for exercise, mobile health intervention tailoring, outcome expectations and goals for physical activity. Interviews were transcribed verbatim, and a three-member study team employed deductive and inductive thematic analysis using Dedoose. The sample size provided sufficient data to reach saturation.

Results: Physical activity was perceived as the ability to maintain daily living activities and address health goals such as becoming and maintaining physical fitness. Previous experiences with physical activity varied among participants and were influenced by chronic illnesses, motivation and interest in physical activity, and availability of social support. Congruent with the two-minds theory, participants reported intuitive-level experiences as barriers to physical activity. These include antiretroviral side effects, lack of self-confidence, and aging. COVID-19 was also noted as a significant barrier. Consistent with the narrative system, participants identified changes in health status, feeling better and having improved sleep, body changes (e.g., weight loss), and changes in relationships as reasons for and benefits of physical activity. Additionally, most participants reported lifestyle changes such as quitting substance use, diet changes, and changes to their social network, all of which helped sustain their increased physical activity. PWH felt that conversations with their healthcare providers supporting their exercise goals was critical to helping them engage in physical activity, but was rarely received.

Conclusion: Understanding how older PWH experience and perceive physical activity is critical to developing tailored strategies and structuring service delivery within the healthcare setting to improve health by supporting a physically active life.

Coxiella burnetii Infection Associated With Thromboangiitis Obliterans-like Phenomena With Digital Autoamputation: A Case Report and Review of Q Fever-Associated Autoimmunity

We present a case of a patient with chronic Q fever who presented with digital necrosis, autoamputations, and positive anticentromere antibody, mimicking a scleroderma vasculopathy or thromboangiitis obliterans. Coxiella burnetii infection has long been associated with the presence of autoantibodies and autoimmune phenomena including vasculitis. Clinicians should consider Q fever testing in patients with new-onset autoimmune diseases or autoantibodies and appropriate exposure histories.

Pulmonary and Physical Function Limitations in Aging Men with and without HIV from the Multicenter AIDS Cohort Study

We sought to determine effects of age, HIV serostatus, and smoking on the associations between pulmonary function and physical function impairments using Multicenter AIDS Cohort Study data. Associations between physical function outcomes gait speed (m/sec) and grip strength (kg) with normalized pulmonary function tests (diffusion capacity for carbon monoxide (DLCO, n=1,048) and forced expiratory volume in one second (FEV1, n=1,029)) were examined. Adjusted mixed-effects models included interaction terms to assess effect modification. 574(55%) were HIV+, with median age 57(IQR=48,64) and mean cumulative smoking pack-years 12.2(SD=19.0). 349(33%) had impaired DLCO (<80% of predicted) and 130(13%) had impaired FEV1 (<80% of predicted). Participants with impaired DLCO had weaker grip strength than those with normal DLCO (estimate= -3.5[95% CI=-4.6,-2.4]kg; p<0.001). Participants with impaired DLCO had slower gait speed than those with normal DLCO (estimate= -0.04[95% CI= -0.06,-0.02]m/sec; p=0.002). Age modified the DLCO effect on gait (p-interaction=0.01) but not grip (p-interaction=0.09). The association between decreased DLCO and slower gait was more pronounced in older participants. Smoking or HIV serostatus did not significantly modify the DLCO effect on gait (all p-interaction≥0.14) or grip (p-interaction=0.74, p-interaction=0.058, respectively). As with DLCO, participants with impaired FEV1 had weaker grip strength (estimate=-3.0[95% CI= -4.7,-1.3]kg; p<0.001) than those with normal FEV1. FEV1 was not associated with gait speed(p=0.98). Age, HIV serostatus or smoking did not modify the associations between FEV1 and gait speed or grip strength (all p-interaction>0.05). Associations between lower DLCO/FEV1 and decreased physical function suggest that interventions to improve pulmonary function may also preserve physical function with aging.

Motor and Pulmonary Function and Mobility Disability Among Black and White Older Adults With and Without HIV

Black-White disparities in gait speed have been observed in studies of adults reporting HIV, consistent with work among older adults without HIV. However, it is unknown if racial differences exist among adults with HIV for other mobility-related factors. We aimed to determine if racial differences exist in mobility disability among older adults with and without HIV and assess if pulmonary and motor function contribute to mobility disability. We examined older adults age 50+ with HIV (N=177; 72% Black) and without HIV (N=191; 68% Black). Motor function summarized 10 motor performances including gait speed; pulmonary function summarized 3 measures assessed using hand-held spirometry. Mobility disability was based on self-report. In regression models adjusted for age, sex, medical conditions, and smoking, neither race nor HIV status were associated with mobility-related factors. However, in models stratified by HIV status, Blacks with HIV had worse motor (β=-4.3, p=0.04) and pulmonary function (β=-50.5, <0.001) and higher odds of mobility disability (odds ratio [OR]=2.9, 95% confidence interval [CI]=1.01-8.2) compared to Whites with HIV. Racial differences were not apparent among uninfected participants in motor function, pulmonary function, or mobility disability. In subsequent models, racial differences in mobility disability were attenuated and no longer significant in HIV when adjusting for motor function (OR=0.88 per/% higher motor composite, 95% CI=0.84-0.93). Racial differences in mobility disability in HIV were unaffected when controlling for pulmonary function. Results suggest that Blacks with HIV have greater mobility disability compared to Whites with HIV, and these differences are due to differences in motor function.

2244. Non-AIDS Cancers Contribute to an Increasing Proportion of Deaths in Persons Living with HIV at a Single University-Based Clinic

Background

Mortality for people living with HIV (PLWH) has drastically decreased since the mid-1990s, and the proportion of deaths due to non-HIV-related conditions has increased.

Methods

Deceased PLWH were identified within a single academic medical center. Cause of death was determined by chart review, clinic providers, and when available autopsy and toxicology data. Chart review of comorbidities, demographics and preventable causes of cancer was conducted for deaths during the period of 2013–2017.

Results

The proportion of AIDS-related deaths decreased markedly between 1995 and 2017, while the proportion of deaths from non-AIDS cancers has increased (figure). Patients with non-AIDS cancers were older, had a higher CD4 count and greater proportion with undetectable viral load, and were more likely to be male; over 80% were current or prior smokers (table). Among all deaths from 2013 to 2017, 44% of eligible patients received colon cancer screening, 66% received cervical cancer screening, and 29% received breast cancer screening. Of patients who died from HCC, one out of six had imaging for HCC within 1 year and none within 6 months of diagnosis.

Conclusion

Improvements in cancer screening and preventative health measures including smoking cessation and lifestyle improvement education may help to reduce the increasing proportion of non-AIDS cancer-related deaths among PLWH.

Disclosures

All authors: No reported disclosures.

583. Demographic Factors and Clinical Outcomes Associated with Mental Health Medication Use in People Living with HIV

Background

Mental health (MH) conditions and pain are common among people living with HIV (PLWH). An understanding of factors associated with prescriptions for these conditions and clinical impact of the prescriptions may improve care of MH disorders in PLWH.

Methods

The use of mental health/pain-related medications was examined among PLWH within the AIDS Clinical Trials Group A5322 (HAILO) study. Use of medications (any use and class) was compared by sex. Multivariable logistic models estimated the association between MH medications (any/none) with (i) insurance status and race/ethnicity and (ii) baseline and incident slow gait (>1 second/m) and neurocognitive impairment (NCI) over 4 years.

Results

Of 1035 participants, the median age was 51. 81% were men, 30% black, and 20% Hispanic. Similar numbers of men (34%) and women (38%) were on MH medications (P = 0.19).Women were more likely to be prescribed opioids (12% vs. 5%; P < 0.001); other classes were similar. In multivariable models, MH-medicated PLWH were more likely to have Medicare (odds ratio [OR] 2.50, 95% CI 1.50–4.16, P < 0.001) or public insurance (1.85; 1.23–2.78, P = 0.003) vs. no/unknown insurance; and less likely to be Hispanic vs. white (0.48; 0.33–0.69; P < 0.001). MH-medicated PLWH had greater odds of baseline slow gait (1.80; 1.34–2.40; P < 0.001). The sex-specific ORs for NCI were qualitatively different (men: 1.70; 1.09–2.66; women: 0.96; 0.43–2.18); but this difference was not significant in the multivariable model (P interaction = 0.227). There was an increased risk of incident slow gait among MH-medicated men but not women (hazard ratio 1.74; 1.22–2.48 vs. 0.76; 0.38–1.52, P interaction = 0.038), and a trend toward increased risk of incident NCI (1.76; 0.91, 3.39, P = 0.09) for both sexes.

Conclusion

Our results highlight socioeconomic and ethnic differences in prescription of MH medications. The higher proportion of opiate prescriptions among women needs confirmation and should be a priority for intervention. The greater risk of baseline NCI and incident slow gait among men may be the result of differences in toxicity, drug interactions, or persistent mental health symptoms; further investigation is needed to optimize outcomes in PLWH and prescription of mental health medications.

Disclosures

All authors: No reported disclosures.

Bacterial community associated with Pfiesteria-like dinoflagellate cultures

Dinoflagellates (Eukaryota; Alveolata; Dinophyceae) are single-cell eukaryotic microorganisms implicated in many toxic outbreaks in the marine and estuarine environment. Co-existing with dinoflagellate communities are bacterial assemblages that undergo changes in species composition, compete for nutrients and produce bioactive compounds, including toxins. As part of an investigation to understand the role of the bacteria in dinoflagellate physiology and toxigenesis, we have characterized the bacterial community associated with laboratory cultures of four 'Pfiesteria-like' dinoflagellates isolated from 1997 fish killing events in Chesapeake Bay. A polymerase chain reaction with oligonucleotide primers specific to prokaryotic 16S rDNA gene sequences was used to characterize the total bacterial population, including culturable and non-culturable species, as well as possible endosymbiotic bacteria. The results indicate a diverse group of over 30 bacteria species co-existing in the dinoflagellate cultures. The broad phylogenetic types of dinoflagellate-associated bacteria were generally similar, although not identical, to those bacterial types found in association with other harmful algal species. Dinoflagellates were made axenic, and the culturable bacteria were added back to determine the contribution of the bacteria to dinoflagellate growth. Confocal scanning laser fluorescence microscopy with 16S rDNA probes was used to demonstrate a physical association of a subset of the bacteria and the dinoflagellate cells. These data point to a key component in the bacterial community being species in the marine alpha-proteobacteria group, most closely associated with the alpha-3 or SAR83 cluster.

Strain-specific differentiation of lactococci in mixed starter culture populations using randomly amplified polymorphic DNA-derived probes

A hydrophobic grid membrane filtration (HGMF) colony hybridization assay was developed that allows strain-specific differentiation of defined bacterial populations. The randomly amplified polymorphic DNA (RAPD) fingerprinting technique was used to identify potential signature nucleic acid sequences unique to each member of a commercial cheese starter culture blend. The blend consisted of two closely related Lactococcus lactis subsp. cremoris strains, 160 and 331, and one L. lactis subsp. lactis strain, 210. Three RAPD primers (OPX 1, OPX 12, and OPX 15) generated a total of 32 products from these isolates, 20 of which were potential strain-specific markers. Southern hybridization analyses revealed, that the RAPD-generated signature sequences OPX15-0.95 and a 0.36-kb HaeIII fragment of OPX1-1.0b were specific for strains 331 and 210, respectively, within the context of the test starter culture blend. These strain-specific probes were used in a HGMF colony hybridization assay. Colony lysis, hybridization, and nonradioactive detection parameters were optimized to allow specific differentiation and quantitation of the target strains in the mixed starter culture population. When the 210 and 331 probes were tested at their optimal hybridization temperatures against single cultures, they detected 100% of the target strain CFUs, without cross-reactivity to the other strains. The probes for strains 210 and 331 also successfully detected their targets in blended cultures even with a high background of the other two strains.