Cardiac complication after experimental human malaria infection: a case report

A 20 year-old healthy female volunteer participated in a clinical Phase I and IIa safety and efficacy trial with candidate malaria vaccine PfLSA-3-rec adjuvanted with aluminium hydroxide. Eleven weeks after the third and last immunization she was experimentally infected by bites of Plasmodium falciparum-infected mosquitoes. When the thick blood smear became positive, at day 11, she was treated with artemether/lumefantrine according to protocol. On day 16 post-infection i.e. two days after completion of treatment, she woke up with retrosternal chest pain. She was diagnosed as acute coronary syndrome and treated accordingly. She recovered quickly and her follow-up was uneventful. Whether the event was related to the study procedures such as the preceding vaccinations, malaria infection or antimalarial drugs remains elusive. However, the relation in time with the experimental malaria infection and apparent absence of an underlying condition makes the infection the most probable trigger. This is in striking contrast, however, with the millions of malaria cases each year and the fact that such complication has never been reported in the literature. The rare occurrence of cardiac events with any of the preceding study procedures may even support a coincidental finding

Species distribution and in vitro antifungal susceptibility of oral yeast isolates from Tanzanian HIV-infected patients with primary and recurrent oropharyngeal candidiasis

\ud In Tanzania, little is known on the species distribution and antifungal susceptibility profiles of yeast isolates from HIV-infected patients with primary and recurrent oropharyngeal candidiasis. A total of 296 clinical oral yeasts were isolated from 292 HIV-infected patients with oropharyngeal candidiasis at the Muhimbili National Hospital, Dar es Salaam, Tanzania. Identification of the yeasts was performed using standard phenotypic methods. Antifungal susceptibility to fluconazole, itraconazole, miconazole, clotrimazole, amphotericin B and nystatin was assessed using a broth microdilution format according to the guidelines of the Clinical and Laboratory Standard Institute (CLSI; M27-A2). Candida albicans was the most frequently isolated species from 250 (84.5%) patients followed by C. glabrata from 20 (6.8%) patients, and C. krusei from 10 (3.4%) patients. There was no observed significant difference in species distribution between patients with primary and recurrent oropharyngeal candidiasis, but isolates cultured from patients previously treated were significantly less susceptible to the azole compounds compared to those cultured from antifungal naïve patients. C. albicans was the most frequently isolated species from patients with oropharyngeal candidiasis. Oral yeast isolates from Tanzania had high level susceptibility to the antifungal agents tested. Recurrent oropharyngeal candidiasis and previous antifungal therapy significantly correlated with reduced susceptibility to azoles antifungal agents.\u

Gut dysbiosis associates with cytokine production capacity in viral-suppressed people living with HIV

BACKGROUND: People living with human immunodeficiency virus (PLHIV) are exposed to chronic immune dysregulation, even when virus replication is suppressed by antiretroviral therapy (ART). Given the emerging role of the gut microbiome in immunity, we hypothesized that the gut microbiome may be related to the cytokine production capacity of PLHIV.METHODS: To test this hypothesis, we collected metagenomic data from 143 ART-treated PLHIV and assessed the ex vivo production capacity of eight different cytokines [interleukin-1β (IL-1β), IL-6, IL-1Ra, IL-10, IL-17, IL-22, tumor necrosis factor, and interferon-γ] in response to different stimuli. We also characterized CD4 + T-cell counts, HIV reservoir, and other clinical parameters. RESULTS: Compared with 190 age- and sex-matched controls and a second independent control cohort, PLHIV showed microbial dysbiosis that was correlated with viral reservoir levels (CD4 + T-cell-associated HIV-1 DNA), cytokine production capacity, and sexual behavior. Notably, we identified two genetically different P. copri strains that were enriched in either PLHIV or healthy controls. The control-related strain showed a stronger negative association with cytokine production capacity than the PLHIV-related strain, particularly for Pam3Cys-incuded IL-6 and IL-10 production. The control-related strain is also positively associated with CD4 + T-cell level. CONCLUSIONS: Our findings suggest that modulating the gut microbiome may be a strategy to modulate immune response in PLHIV.</p

Chronic HIV infection induces transcriptional and functional reprogramming of innate immune cells

Chronic inflammation and immune dysfunction play a key role in the development of non-AIDS-related comorbidities. The aim of our study was to characterize the functional phenotype of immune cells in people living with HIV (PLHIV). We enrolled a cross-sectional cohort study of PLHIV on stable antiretroviral therapy and healthy controls. We assessed ex vivo cytokine production capacity and transcriptomics of monocytes and T cells upon bacterial, fungal, and viral stimulation. PLHIV exhibited an exacerbated proinflammatory profile in monocyte-derived cytokines, but not in lymphocyte-derived cytokines. Particularly, the production of the IL-1 beta to imiquimod, E. coli LPS, and Mycobacterium tuberculosis was increased, and this production correlated with plasma concentrations of high-sensitivity C-reactive protein and soluble CD14. This increase in monocyte responsiveness remained stable over time in subsequent blood sampling after more than 1 year. Transcriptome analyses confirmed priming of the monocyte IL-1 beta pathway, consistent with a monocyte-trained immunity phenotype. Increased plasma concentrations of beta-glucan, a well-known inducer of trained immunity, were associated with increased innate cytokine responses. Monocytes of PLHIV exhibited a sustained proinflammatory immune phenotype with priming of the IL-1 beta pathway. Training of the innate immune system in PLHIV likely plays a role in long-term HIV complications and provides a promising therapeutic target for inflammation-related comorbidities

Liver Steatosis is Prevalent in Lean People With HIV and Associated With Exposure to Antiretroviral Treatment - A Cross-sectional Study

Background: Steatotic liver disease is suggested to have a higher prevalence and severity in people with HIV (PHIV), including in those with a normal body mass index (BMI). In this study, we used data from the 2000HIV cohort to (1) assess the prevalence of liver steatosis and fibrosis in lean versus overweight/obese PHIV and (2) assess associations in these subgroups between steatosis and fibrosis with traditional risk factors and HIV-specific characteristics. Methods: The 2000HIV study cohort comprises 1895 virally suppressed PHIV that were included between 2019 and 2021 in 4 HIV treatment centers in the Netherlands. The majority (58.5%) underwent vibration-controlled transient elastography for the assessment of liver steatosis and fibrosis. The prevalence of steatosis (controlled attenuation parameter ≥263 dB/m) and fibrosis (liver stiffness measurement ≥7.0 kPa) was estimated. Multiple factors including HIV characteristics and antiretroviral drugs were tested in a logistic regression model for association with steatosis and fibrosis. Analyses were performed separately for lean (Asian descent: BMI &lt; 23 kg/m2, other descent: BMI &lt; 25 kg/m2) and overweight/obese (other BMI) participants. Results: Of 1050 PHIV including 505 lean and 545 overweight/obese PHIV, liver steatosis was observed in 37.7% of the overall study population, 19.7% of lean, and 54% of overweight/obese PHIV, whereas fibrosis was observed in 9.0% of the overall study population, 5.9% of lean, and 12.0% of overweight/obese PHIV. All associations with fibrosis and most associations with steatosis concerned metabolic factors such as type 2 diabetes mellitus (overall population: adjusted odds ratio [aOR] for steatosis: 2.3 [1.21-4.4], P =. 011; aOR for fibrosis: 3.7 [1.82-7.53], P &lt;. 001). Furthermore, in lean PLHIV, liver steatosis was associated with CD4 and CD8 counts at enrollment, dual therapy, and history of treatment with raltegravir (aOR: 3.6 [1.53-8.47], P =. 003), stavudine (aOR: 3.73 [1.69-8.2], P =. 001), and indinavir (aOR: 3.86 [1.59-9.37], P =. 003). These associations were not observed in overweight/obese PHIV. Conclusions: Liver steatosis was highly prevalent, affecting approximately one-fifth of lean PHIV and half of overweight/obese PHIV. Fibrosis was observed in a minority. Both steatosis and fibrosis were associated with traditional metabolic risk factors. In addition, (prior) exposure to specific antiretroviral drugs was associated liver steatosis in lean, but not in overweight/obese PHIV. Implementing increased screening protocols could enhance the identification of steatotic liver disease in lean PHIV.</p

High-throughput proteomic analysis reveals systemic dysregulation in virally suppressed people living with HIV

BACKGROUND. People living with HIV (PLHIV) receiving antiretroviral therapy (ART) exhibit persistent immune dysregulation and microbial dysbiosis, leading to development of cardiovascular diseases (CVDs). We initially compared plasma proteomic profiles between 205 PLHIV and 120 healthy control participants (HCs) and validated the results in an independent cohort of 639 PLHIV and 99 HCs. Differentially expressed proteins (DEPs) were then associated to microbiome data. Finally, we assessed which proteins were linked with CVD development in PLHIV. METHODS. Proximity extension assay technology was used to measure 1,472 plasma proteins. Markers of systemic inflammation (C-reactive protein, D-dimer, IL-6, soluble CD14, and soluble CD163) and microbial translocation (IFABP) were measured by ELISA, and gut bacterial species were identified using shotgun metagenomic sequencing. Baseline CVD data were available for all PLHIV, and 205 PLHIV were recorded for development of CVD during a 5-year follow-up. RESULTS. PLHIV receiving ART had systemic dysregulation of protein concentrations, compared with HCs. Most of the DEPs originated from the intestine and lymphoid tissues and were enriched in immune- and lipid metabolism-related pathways. DEPs originating from the intestine were associated with specific gut bacterial species. Finally, we identified upregulated proteins in PLHIV (GDF15, PLAUR, RELT, NEFL, COL6A3, and EDA2R), unlike most markers of systemic inflammation, associated with the presence and risk of developing CVD during 5-year follow-up. CONCLUSION. Our findings suggest a systemic dysregulation of protein concentrations in PLHIV; some proteins were associated with CVD development. Most DEPs originated from the gut and were related to specific gut bacterial species.</p

A randomized feasibility trial comparing four antimalarial drug regimens to induce Plasmodium falciparum gametocytemia in the controlled human malaria infection model.

Background: Malaria elimination strategies require a thorough understanding of parasite transmission from human to mosquito. A clinical model to induce gametocytes to understand their dynamics and evaluate transmission-blocking interventions (TBI) is currently unavailable. Here, we explore the use of the well-established Controlled Human Malaria Infection model (CHMI) to induce gametocyte carriage with different antimalarial drug regimens. Methods: In a single centre, open-label randomised trial, healthy malaria-naive participants (aged 18–35 years) were infected with Plasmodium falciparum by bites of infected Anopheles mosquitoes. Participants were randomly allocated to four different treatment arms (n = 4 per arm) comprising low-dose (LD) piperaquine (PIP) or sulfadoxine-pyrimethamine (SP), followed by a curative regimen upon recrudescence. Male and female gametocyte densities were determined by molecular assays. Results: Mature gametocytes were observed in all participants (16/16, 100%). Gametocytes appeared 8.5–12 days after the first detection of asexual parasites. Peak gametocyte densities and gametocyte burden was highest in the LD-PIP/SP arm, and associated with the preceding asexual parasite biomass (p=0.026). Male gametocytes had a mean estimated circulation time of 2.7 days (95% CI 1.5–3.9) compared to 5.1 days (95% CI 4.1–6.1) for female gametocytes. Exploratory mosquito feeding assays showed successful sporadic mosquito infections. There were no serious adverse events or significant differences in the occurrence and severity of adverse events between study arms (p=0.49 and p=0.28). Conclusions: The early appearance of gametocytes indicates gametocyte commitment during the first wave of asexual parasites emerging from the liver. Treatment by LD-PIP followed by a curative SP regimen, results in the highest gametocyte densities and the largest number of gametocyte-positive days. This model can be used to evaluate the effect of drugs and vaccines on gametocyte dynamics, and lays the foundation for fulfilling the critical unmet need to evaluate transmission-blocking interventions against falciparum malaria for downstream selection and clinical development. Funding: Funded by PATH Malaria Vaccine Initiative (MVI). Clinical trial number: NCT02836002

The Architecture of Circulating Immune Cells Is Dysregulated in People Living With HIV on Long Term Antiretroviral Treatment and Relates With Markers of the HIV-1 Reservoir, Cytomegalovirus, and Microbial Translocation

Long-term changes in the immune system of successfully treated people living with HIV (PLHIV) remain incompletely understood. In this study, we assessed 108 white blood cell (WBC) populations in a cohort of 211 PLHIV on stable antiretroviral therapy and in 56 HIV-uninfected controls using flow cytometry. We show that marked differences exist in T cell maturation and differentiation between PLHIV and HIV-uninfected controls: PLHIV had reduced percentages of CD4+ T cells and naïve T cells and increased percentages of CD8+ T cells, effector T cells, and T helper 17 (Th17) cells, together with increased Th17/regulatory T cell (Treg) ratios. PLHIV also exhibited altered B cell maturation with reduced percentages of memory B cells and increased numbers of plasmablasts. Determinants of the T and B cell composition in PLHIV included host factors (age, sex, and smoking), markers of the HIV reservoir, and CMV serostatus. Moreover, higher circulating Th17 percentages were associated with higher plasma concentrations of interleukin (IL) 6, soluble CD14, the gut homing chemokine CCL20, and intestinal fatty acid binding protein (IFABP). The changes in circulating lymphocytes translated into functional changes with reduced interferon (IFN)- γ responses of peripheral blood mononuclear cells to stimulation with Candida albicans and Mycobacterium tuberculosis. In conclusion, this comprehensive analysis confirms the importance of persistent abnormalities in the number and function of circulating immune cells in PLHIV on stable treatment.</jats:p

Safety, Immunogenicity, and Protective Efficacy of Intradermal Immunization with Aseptic, Purified, Cryopreserved Plasmodium falciparum Sporozoites in Volunteers Under Chloroquine Prophylaxis

Immunization of volunteers under chloroquine prophylaxis by bites of *Plasmodium falciparum* sporozoite (PfSPZ)–infected mosquitoes induces > 90% protection against controlled human malaria infection (CHMI). We studied intradermal immunization with cryopreserved, infectious PfSPZ in volunteers taking chloroquine (PfSPZ chemoprophylaxis vaccine [CVac]). Vaccine groups 1 and 3 received 3x monthly immunizations with 7.5 x 10^4 PfSPZ. Control groups 2 and 4 received normal saline. Groups 1 and 2 underwent CHMI (#1) by mosquito bite 60 days after the third immunization. Groups 3 and 4 were boosted 168 days after the third immunization and underwent CHMI (#2) 137 days later. Vaccinees (11/20, 55%) and controls (6/10, 60%) had the same percentage of mild to moderate solicited adverse events. After CHMI #1, 8/10 vaccinees (group 1) and 5/5 controls (group 2) became parasitemic by microscopy; the two negatives were positive by quantitative real-time polymerase chain reaction (qPCR). After CHMI #2, all vaccinees in group 3 and controls in group 4 were parasitemic by qPCR. Vaccinees showed weak antibody and no detectable cellular immune responses. Intradermal immunization with up to 3 x 10^5 PfSPZ-CVac was safe, but induced only minimal immune responses and no sterile protection against Pf CHMI. INTRODUCTIO