HIV and hypertension epidemiology

Prevalence of Age-Related Macular Degeneration in Patients with Chronic Exposure to P2X7R Inhibitors

PURPOSE

P2X7 receptor (P2X7R) is a purinergic cation channel whose activation has been linked with age-related macular degeneration (ARMD). Several nucleoside reverse transcriptase inhibitors, zidovudine (AZT), lamivudine (3TC) and abacavir (ABC), have been shown to inhibit P2X7R and improve outcomes in animal models of ARMD. Our aim is to investigate the association between chronic AZT, 3TC, and ABC therapy and ARMD in a clinical setting.

METHODS

This is a retrospective cohort study comparing 445 patients with HIV and confirmed usage of AZT, 3TC, and ABC against 200 patients with HIV without usage of AZT, 3TC, and ABC and 445 non-HIV infected patients. Fundus examination and spectral domain optical coherence tomography (SD-ODT) were used to measure prevalence of early-intermediate stage ARMD, geographic atrophy, and exudative ARMD.

RESULTS

There was no statistically significant difference in the prevalence of early-intermediate stage ARMD between the HIV infected patients with a history of AZT, 3TC, and ABC use and the HIV infected patients without AZT, 3TC, and ABC use (p = 0.887). There was also no statistically significant difference in the prevalence of geographical atrophy (p = 0.062) and exudative AMD (p > 0.999) between the HIV infected patients with a history of AZT, 3TC, and ABC use and non-HIV infected patients.

CONCLUSION

We did not find an effect of P2X7R inhibiting antiretrovirals usage on early-intermediate stage ARMD, geographical atrophy, or exudative ARMD. Studies with larger cohort and more rigorous medication history are needed to assess the effects on geographical atrophy or exudative ARMD.

Feasibility of Emergency Department-Initiated HIV Pre-Exposure Prophylaxis

Introduction

Pre-exposure prophylaxis (PrEP) for HIV-using antiretroviral medication in non-infected individuals to prevent HIV-has immense potential to slow the spread of the virus. However, uptake has been insufficient, and stark racial disparities exist in both HIV acquisition and PrEP usage, making PrEP access a health equity issue. A promising venue to engage high-risk populations in PrEP care is the emergency department (ED); however, existing ED PrEP initiatives have been costly or have had limited success. We hypothesize that two strategies could overcome these barriers: prescribing PrEP during an ED visit and providing patients with an initial supply of PrEP medication in the ED. Here, we describe the results of a qualitative study exploring multidisciplinary emergency clinicians and HIV clinicians' needs and views about the feasibility of such an initiative.

Methods

We conducted 22 semi-structured interviews with multidisciplinary clinicians from an urban, safety-net medical center in the ED and the on-site HIV clinic that provides PrEP services. We performed thematic analysis to summarize challenges and potential solutions described by participants.

Results

Participants' responses fell into three thematic categories: operational challenges; patient-level considerations; and potential impacts. Operational challenges highlighted the difficulty of PrEP initiation in a busy ED and clinician support needs. Patient-level considerations included the complex psychosocial needs of ED patients who could benefit from PrEP. Finally, participants anticipated that an ED-based PrEP initiation program could positively impact both individual patients and public health.

Conclusion

Interviews with emergency department and HIV clinic staff revealed important considerations and potential solutions for ED-initiated PrEP workflows. Clinicians in both specialties were enthusiastic about such an initiative, which could facilitate its success. This study lays the groundwork for the future design of an efficient and innovative workflow to leverage the ED as an essential entry point into HIV prevention services.

Dendritic cell epithelial sodium channel induced inflammation and salt-sensitive hypertension

PURPOSE OF REVIEW

Salt sensitivity of blood pressure (SSBP) is an independent risk factor for cardiovascular disease. Epithelial sodium channel (ENaC) plays a critical role in renal electrolyte and volume regulation and has been implicated in the pathogenesis of SSBP. This review describes recent advances regarding the role of ENaC-dependent inflammation in the development of SSBP.

RECENT FINDINGS

We recently found that sodium enters dendritic cells via ENaC, a process regulated by serum/glucocorticoid-regulated kinase 1 and epoxyeicosatrienoic acid 14,15. Sodium entry activates NADPH oxidase, leading to the production of isolevuglandins (IsoLGs). IsoLGs adduct self-proteins to form neoantigens in dendritic cells that activate T cells and result in the release of cytokines promoting sodium retention, kidney damage, and endothelial dysfunction in SSBP. Additionally, we described a novel mechanistic pathway involving ENaC and IsoLG-dependent NLRP3 inflammasome activation. These findings hold promise for the development of novel diagnostic biomarkers and therapeutic options for SSBP.

SUMMARY

The exact mechanisms underlying SSBP remain elusive. Recent advances in understanding the extrarenal role of ENaC have opened a new perspective, and further research efforts should focus on understanding the link between ENaC, inflammation, and SSBP.