Benign ethnic neutropenia in a South African population, and its association with HIV acquisition and adverse event reporting in an HIV vaccine clinical trial

Meta-analysis of Pregnancy Events in Biomedical HIV Prevention Trials in Sub-Saharan Africa: Implications for Gender Transformative Trials

Historically, pregnant and lactating populations (PLP) have been excluded or disenrolled from biomedical HIV prevention trials, despite being more likely to acquire HIV during pregnancy and the post-partum period. We conducted a meta-analysis of pregnancy events in biomedical HIV prevention trials in sub-Saharan Africa to support trialists moving toward more inclusive clinical and implementation studies. We searched peer-reviewed literature reporting pregnancy events and contraceptive requirements in HIV prevention trials between 2001 and 2022. We hypothesized four variables to explain variation: contraceptive requirements, study start year, study product, and sub-region. We fit a meta-analytic model to estimate individual effect sizes and sampling variances, then conducted sub-group analyses to assess moderating effects. We identified 38 references for inclusion, across which the proportion of pregnancy events was 8% (95% confidence interval [CI]: 6-10%) with high heterogeneity (I2 = 99%). Studies not requiring contraceptives (21%, 95%CI: 7-48%) reported a significantly higher proportion of pregnancy events than studies requiring two methods (5%, 95%CI: 2-10%). Studies launched between 2001 and 2007 (11%, 95%CI: 8-16%), microbicide gel trials (12%, 95%CI: 8-18%), and studies conducted in Western Africa (28%, 95%CI: 13-51%) reported higher proportions of pregnancy events than reference groups. Together, these variables have a moderating effect on pregnancy events (p < 0.0001), explaining 63% of heterogeneity in trials. Results describe how, over time, more stringent contraceptive requirements reduced pregnancy events, which ensured necessary statistical power but limited reproductive choice by participants. With the move toward continuing PLP on experimental products, trialists can utilize estimated pregnancy events reported here to inform strategies that accommodate participants' changing fertility preferences.

Lower Neutrophil Count Without Clinical Consequence Among Children of African Ancestry Living With HIV in Canada

OBJECTIVE

To investigate the association between African ancestry and neutrophil counts among children living with HIV (CLWH). We also examined whether medications, clinical conditions, hospitalization, or HIV virologic control were associated with low neutrophil counts or African ancestry.

DESIGN

We conducted a secondary analysis of the Early Pediatric Initiation Canada Child Cure Cohort (EPIC4) Study, a multicenter prospective cohort study of CLWH across 8 Canadian pediatric HIV care centers.

METHODS

We classified CLWH according to African ancestry, defined as "African," "Caribbean," or "Black" maternal race. Longitudinal laboratory data (white blood cells, neutrophils, lymphocytes, viral load, and CD4 count) and clinical data (hospitalizations, AIDS-defining conditions, and treatments) were abstracted from medical records.

RESULTS

Among 217 CLWH (median age 14, 55% female), 145 were of African ancestry and 72 were of non-African ancestry. African ancestry was associated with lower neutrophil counts, white blood cell counts, and neutrophil-lymphocyte ratios. Neutrophil count <1.5 × 109/L was detected in 60% of CLWH of African ancestry, compared with 31% of CLWH of non-African ancestry (P < 0.0001), representing a 2.0-fold higher relative frequency (95% CI: 1.4-2.9). Neutrophil count was on average 0.74 × 109/L (95% CI: 0.45 to 1.0) lower in CLWH of African ancestry (P < 0.0001). Neither neutrophil count<1.5 × 109/L nor African ancestry was associated with medications, hospitalizations, AIDS-defining conditions, or markers of virologic control (viral load, sustained viral suppression, and lifetime nadir CD4).

CONCLUSIONS

In CLWH, African ancestry is associated with lower neutrophil counts, without clinical consequences. A flexible evaluation of neutrophil counts in CLWH of African ancestry may avoid unnecessary interventions.

Hematological Complications of Human Immunodeficiency Virus (HIV) Infection: An Update From an HIV-Endemic Setting

Medical professionals, particularly in regions with a high burden of human immunodeficiency virus (HIV), should be alert to the hematological complications of HIV, which may include cytopenias, malignancy, and coagulation disturbances. Patients may present with these conditions as the first manifestation of HIV infection. Hematological abnormalities are often multifactorial with opportunistic infections, drugs, malignancy, and HIV infection itself contributing to the clinical presentation, and the diagnosis should consider all these factors. Life-threatening hematological complications requiring urgent diagnosis and management include thrombotic thrombocytopenic purpura, superior mediastinal syndrome, spinal cord compression, and tumor lysis syndrome due to aggressive lymphoma. Antiretroviral therapy is the therapeutic backbone, including for patients with advanced HIV, in addition to specific therapy for the complication. This article reviews the impact of HIV on the hematological system and provides a clinical and diagnostic approach, including the role of a bone marrow biopsy, focusing on perspectives from sub-Saharan Africa.

Prospects for targeting ACKR1 in cancer and other diseases

The chemokine network is comprised of a family of signal proteins that encode messages for cells displaying chemokine G-protein coupled receptors (GPCRs). The diversity of effects on cellular functions, particularly directed migration of different cell types to sites of inflammation, is enabled by different combinations of chemokines activating signal transduction cascades on cells displaying a combination of receptors. These signals can contribute to autoimmune disease or be hijacked in cancer to stimulate cancer progression and metastatic migration. Thus far, three chemokine receptor-targeting drugs have been approved for clinical use: Maraviroc for HIV, Plerixafor for hematopoietic stem cell mobilization, and Mogalizumab for cutaneous T-cell lymphoma. Numerous compounds have been developed to inhibit specific chemokine GPCRs, but the complexity of the chemokine network has precluded more widespread clinical implementation, particularly as anti-neoplastic and anti-metastatic agents. Drugs that block a single signaling axis may be rendered ineffective or cause adverse reactions because each chemokine and receptor often have multiple context-specific functions. The chemokine network is tightly regulated at multiple levels, including by atypical chemokine receptors (ACKRs) that control chemokine gradients independently of G-proteins. ACKRs have numerous functions linked to chemokine immobilization, movement through and within cells, and recruitment of alternate effectors like β-arrestins. Atypical chemokine receptor 1 (ACKR1), previously known as the Duffy antigen receptor for chemokines (DARC), is a key regulator that binds chemokines involved in inflammatory responses and cancer proliferation, angiogenesis, and metastasis. Understanding more about ACKR1 in different diseases and populations may contribute to the development of therapeutic strategies targeting the chemokine network.

Benign ethnic neutropenia: an analysis of prevalence, timing and identification accuracy in two large inner-city NHS hospitals

BACKGROUND

Benign ethnic neutropenia (BEN) is the most common cause of chronic neutropenia seen in individuals of African, Middle Eastern and West Indian descent. This phenotype is broadly defined by an absolute neutrophil counts (ANC) below 1.8 × 10⁹ cells/L in the absence of other causes, without an increased risk of infection. BEN has been implicated as a potential source of disparity in patients treated with clozapine, the antipsychotic of choice in treatment-resistant schizophrenia. Our main objective was to examine the current level of BEN recognition in a cohort of patients treated with clozapine and the potential impact of unidentified BEN on the initiation and maintenance of clozapine treatment.

METHODS

This was an observational, retrospective analysis of patients registered with clozapine haematological monitoring systems in two large mental health trusts, chosen because they serve an ethnically diverse population. The first objective was to establish certified BEN prevalence in current users of clozapine. The second objective was to explore the stage of treatment at which BEN was identified. The third objective was to evaluate the extent of unrecognised BEN in patients registered on the Central Non-Rechallenge Database (CNRD), a database for patients whose haematological parameters fall below set thresholds when receiving clozapine treatment, meaning they cannot ordinarily be prescribed clozapine again.

RESULTS

The study population comprised of 2020 patients on the clozapine register. 111 patients were monitored under BEN criteria. BEN was mostly identified after a below threshold haematological result or clozapine rechallenge (68%) compared to at clozapine initiation (32%). Eight of the 18 (42%) black patients registered on the CNRD were classified as BEN after assessment by a haematologist. Of these 8 patients, none would have met CNRD criteria again if monitored with BEN criteria at clozapine initiation.

CONCLUSIONS

Current evidence suggests that BEN remains an uncommonly recognised haematological phenotype. Improved timely identification of BEN will reduce unnecessary interruption or discontinuation of clozapine treatment. Our results suggest consideration should also be given to determining BEN status prior to initiating clozapine. Moreover, adoption of current FDA BEN monitoring criteria in the UK may further reduce clozapine discontinuation due to perceived neutropenia as drug toxicity, particularly in treatment-refractory schizophrenia patients.