Survival and health of children who are HIV-exposed uninfected: study protocol for the CHERISH (Children HIV-Exposed Uninfected - Research to Inform Survival and Health) dynamic, prospective, maternal-child cohort study.

INTRODUCTION: CHERISH is designed to establish a long-term sustainable system for measurement of in utero and postnatal exposures and outcomes in children who are HIV-exposed uninfected (HEU) and HIV-unexposed to compare survival, hospitalisation, growth and neurodevelopment in the Western Cape, South Africa. METHODS AND ANALYSIS: During 2022-2025, the CHERISH dynamic cohort is prospectively enrolling pregnant people with and without HIV at 24-36 weeks gestation from one urban and one rural community, following mother-child pairs, including children who are HEU (target N=1200) and HIV-unexposed (target N=600) for 3 years from the child's birth. In-person visits occur at enrolment, delivery, 12 months, 24 months and 36 months with intervening 3-monthly telephone data collection. Children and mothers without HIV are tested for HIV at all in-person visits. Data on exposures and outcomes are collected from routine standardised healthcare documentation, maternal interview, measurement (growth and neurodevelopment) at in-person visits and linkage to the Western Cape Provincial Health Data Centre (survival and hospitalisation). A priori adverse birth outcomes, advanced maternal HIV and maternal mental health are considered potential mediators of outcome disparities in children who are HEU and will be evaluated as such in multivariable models appropriate for each outcome. ETHICS AND DISSEMINATION: Mothers interested in joining the study are taken through a visual informed consent document for their and their child's participation, with the option to consent to anonymised de-identified data being contributed to a public data repository. All data is captured directly into an electronic database using alphanumeric identifiers devoid of identifying information. The cohort study is approved by Human Research Ethics Committees of Stellenbosch University (N20/08/084), University of Cape Town (723/2021) and Western Cape Government (WC_2021_09_007). Findings will be shared with participants, participating communities, local and provincial stakeholders, child health clinicians, researchers and policymakers at local, national and international forums and submitted for publication in peer-reviewed journals.

Study protocol: an observational study of distress, immune function and persistent pain in HIV.

INTRODUCTION: Many people with HIV report both distress and pain. The relationship between distress and pain is bidirectional, but the mechanisms by which distress exacerbates pain are unclear. The inflammatory response to challenge (inflammatory reactivity, IR) may be a partial mediator, given that neuroimmune interactions provide a substrate for IR to also influence neurological reactivity and, thus, pain-related neural signalling. This prospective, observational, case-control study will characterise the relationships between distress, IR, pain-related signalling as captured by induced secondary hyperalgesia (SH), and pain, in people with HIV who report persistent pain (PP) (cases) or no pain (controls). METHODS AND ANALYSIS: One hundred people with suppressed HIV, reporting either PP or no pain, will be assessed two or four times over 6 months. The primary outcomes are distress (Hopkins 25-item symptom checklist), IR (multiplex assay after LPS challenge), and PP (Brief Pain Inventory), assessed at the baseline timepoint, although each will also be assessed at follow-up time points. Induced SH will be assessed in a subsample of 60 participants (baseline timepoint only). To test the hypothesis that IR partly mediates the relationship between distress and pain, mediation analysis will use the baseline data from the PP group to estimate direct and indirect contributions of distress and IR to pain. To test the hypothesis that IR is positively associated with SH, data from the subsample will be analysed with generalised mixed effects models to estimate the association between IR and group membership, with SH as the dependent variable. ETHICS AND DISSEMINATION: Information obtained from this study will be published in peer-reviewed journals and presented at scientific meetings. The study has been approved by the Human Research Ethics Committee of the University of Cape Town (approval number: 764/2019) and the City of Cape Town (ref: 24699). TRIAL REGISTRATION NUMBER: NCT04757987.