Impact of Chronic HIV Infection on Acute Immune Responses to SARS-CoV-2

ABSTRACT

There is mounting evidence that HIV infection is a risk factor for severe presentations of COVID-19. We hypothesized that the persistent immune activation associated with chronic HIV infection contributes to worsened outcomes during acute COVID-19. The goals of this study were to provide an in-depth analysis of immune response to acute COVID-19 and investigate relationships between immune responses and clinical outcomes in an unvaccinated, sex- and race-matched cohort of people with HIV (PWH, n = 20) and people without HIV (PWOH, n = 41). We performed flow cytometric analyses on peripheral blood mononuclear cells from PWH and PWOH experiencing acute COVID-19 (≤21-day postsymptom onset). PWH were younger (median 52 vs 65 years) and had milder COVID-19 (40% vs 88% hospitalized) compared with PWOH. Flow cytometry panels included surface markers for immune cell populations, activation and exhaustion surface markers (with and without SARS-CoV-2-specific antigen stimulation), and intracellular cytokine staining. We observed that PWH had increased expression of activation (eg, CD137 and OX40) and exhaustion (eg, PD1 and TIGIT) markers as compared to PWOH during acute COVID-19. When analyzing the impact of COVID-19 severity, we found that hospitalized PWH had lower nonclassical (CD16 + ) monocyte frequencies, decreased expression of TIM3 on CD4 + T cells, and increased expression of PDL1 and CD69 on CD8 + T cells. Our findings demonstrate that PWH have increased immune activation and exhaustion as compared to a cohort of predominately older, hospitalized PWOH and raises questions on how chronic immune activation affects acute disease and the development of postacute sequelae.

The role of immune activation and antigen persistence in acute and long COVID

In late 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) triggered the global coronavirus disease 2019 (COVID-19) pandemic. Although most infections cause a self-limited syndrome comparable to other upper respiratory viral pathogens, a portion of individuals develop severe illness leading to substantial morbidity and mortality. Furthermore, an estimated 10%-20% of SARS-CoV-2 infections are followed by post-acute sequelae of COVID-19 (PASC), or long COVID. Long COVID is associated with a wide variety of clinical manifestations including cardiopulmonary complications, persistent fatigue, and neurocognitive dysfunction. Severe acute COVID-19 is associated with hyperactivation and increased inflammation, which may be an underlying cause of long COVID in a subset of individuals. However, the immunologic mechanisms driving long COVID development are still under investigation. Early in the pandemic, our group and others observed immune dysregulation persisted into convalescence after acute COVID-19. We subsequently observed persistent immune dysregulation in a cohort of individuals experiencing long COVID. We demonstrated increased SARS-CoV-2-specific CD4⁺ and CD8⁺ T-cell responses and antibody affinity in patients experiencing long COVID symptoms. These data suggest a portion of long COVID symptoms may be due to chronic immune activation and the presence of persistent SARS-CoV-2 antigen. This review summarizes the COVID-19 literature to date detailing acute COVID-19 and convalescence and how these observations relate to the development of long COVID. In addition, we discuss recent findings in support of persistent antigen and the evidence that this phenomenon contributes to local and systemic inflammation and the heterogeneous nature of clinical manifestations seen in long COVID.

Why Wait? The Ethics of Disclosing HIV Screening Results

Counseling patients on their HIV test results is an important part of undergraduate and graduate medical education. However, many trainees and physicians feel ill prepared to counsel patients on potentially distressing results. We present a case involving early disclosure of a false-positive HIV screening test result to a patient and the downstream effects of this premature disclosure. This case highlights the importance of understanding the various HIV testing options available and the importance of education on effectively counseling patients on screening versus confirmatory HIV test results.

Brief Report: Intracellular Cystatin B Levels Are Altered in HIV-Infected Participants With Respect to Neurocognitive Status and Antiretroviral Therapy

ABSTRACT

With advances in HIV treatment, people with HIV (PWH) are living longer but experience aging-related comorbidities, including cognitive deficits, at higher rates than the general population. Previous studies have shown alterations in lysosomal proteins in blood from PWH with severe dementia. However, these markers have not been evaluated in PWH with milder neurocognitive impairment. We sought to determine whether levels of the lysosomal cysteine protease cathepsin B (CatB) and its endogenous inhibitor cystatin B (CysB) were altered in PWH with neurocognitive impairment and whether antiretroviral therapy (ART) further influenced these levels. Peripheral blood mononuclear cells were obtained from the tenofovir arm of a multicenter clinical trial in which ART-naive, HIV+ participants received treatment for 48 weeks (ACTG A5303, NCT01400412). PWH were divided by neurocognitive status (eg, with or without neurocognitive impairment) before ART initiation. Intracellular levels of CatB and CysB were measured in T cells and monocytes by means of flow cytometry. Levels of CysB were significantly decreased in both CD4 + T cells and CD8 + T cells after 48 weeks of ART in HIV+ participants without neurocognitive impairment but not in participants with neurocognitive impairment. Levels of CysB were increased in CD14 + monocytes from the participants with neurocognitive impairment after ART. Levels of CysB and CatB positively correlated regardless of HIV, neurocognitive status, or exposure to ART. These findings suggest that CysB has the potential to provide mechanistic insight into HIV-associated neurocognitive disorders or provide a molecular target for systemic monitoring or treatment of neurocognitive impairment in the context of ART and should be investigated further.