Chronic chikungunya arthritis is a debilitating post-viral inflammatory arthritis with no established evidence-based therapy. Regulatory T cell (Treg) dysfunction may contribute to persistent inflammation, and low-dose interleukin-2 (IL-2) may restore immune regulation. We evaluated the immunomodulatory effects of low-dose IL-2 using peripheral blood mononuclear cells from adults with laboratory-confirmed chronic chikungunya arthritis in Atlántico, Colombia. Cells were treated ex vivo with recombinant IL-2 or an IL-2/anti-IL-2 monoclonal antibody complex in the presence of CD2/CD3/CD28 stimulation beads, followed by flow cytometric assessment of effector T cells and Tregs. Low-dose IL-2 treatments ex vivo did not increase total Treg frequency but selectively increased activated suppressor Tregs while decreasing activated T effector cells, enhancing Treg CTLA-4 and HLA-DR expression, and reducing Ki67 expression in effector T cells. IL-2 complex treatment decreased cytokine-secreting Tregs, and IL-10 and TGF-β were not associated with IL-2 treatment status or with Teff/Treg balance, suggesting limited utility as pharmacodynamic biomarkers of low-dose IL-2 treatments. These findings support the use of activated suppressor Tregs, Treg CTLA-4, and HLA-DR expression as candidate biologic endpoints for evaluation in future trials of low-dose IL-2 in chikungunya arthritis.

OBJECTIVE:To define the relationship between chronic chikungunya post-viral arthritis disease severity, cytokine response and T cell subsets in order to identify potential targets for therapy. METHODS:Participants with chikungunya arthritis were recruited from Colombia from 2019-2021. Arthritis disease severity was quantified using the Disease Activity Score-28 and an Arthritis-Flare Questionnaire adapted for chikungunya arthritis. Plasma cytokine concentrations (interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, interferon-γ and tumor necrosis factor (TNF)) were measured using a Meso Scale Diagnostics assay. Peripheral blood T cell subsets were measured using flow cytometry. RESULTS:Among participants with chikungunya arthritis (N = 158), IL-2 levels and frequency of regulatory T cells (Tregs) were low. Increased arthritis disease activity was associated with higher levels of inflammatory cytokines (IL-6, TNF and CRP) and immunoregulatory cytokine IL-10 (p<0.05). Increased arthritis flare activity was associated with higher Treg frequencies (p<0.05) without affecting T effector (Teff) frequencies, Treg/Teff ratios and Treg subsets. Finally, elevated levels of IL-2 were correlated with increased Treg frequency, percent Tregs out of CD4+ T cells, and Treg subsets expressing immunosuppressive markers, while also correlating with an increased percent Teff out of live lymphocytes (p<0.05). CONCLUSION:Chikungunya arthritis is characterized by increased inflammatory cytokines and deficient IL-2 and Treg responses. Greater levels of IL-2 were associated with improved Treg numbers and immunosuppressive markers. Future research may consider targeting these pathways for therapy.

Background Dengue vascular permeability syndrome is the primary cause of death in severe dengue infections. The protective versus potentially pathogenic role of dengue nonstructural protein-1 (NS1) antibodies are not well understood. The main goal of this analysis was to characterize the relationship between free NS1 concentration and NS1 antibody titers in primary and secondary dengue infection to better understand the presence and duration of NS1 antibody complexes in clinical dengue infections.Methods Hospitalized participants with acute dengue infection were recruited from Northern Colombia between 2018 and 2020. Symptom assessment, including dengue signs and symptoms, chart review, and blood collection, was performed. Primary versus secondary dengue was assessed serologically. NS1 titers and anti-NS1 antibodies were measured daily.Results Patients with secondary infection had higher antibody titers than those in primary infection, and there was a negative correlation between anti-NS1 antibody titer and NS1 protein. We demonstrate that in a subset of secondary infection, there were indeed NS1 antigen-antibody complexes on the admission day during the febrile phase that were not detectable by the recovery phase. Furthermore, dengue infection status was associated with higher circulating sialidases.Discussion The negative correlation between antibody and protein suggests that antibodies may play a role in clearing this viral protein. Secondary infections of dengue virus were characterized by higher NS1 antibodies. There was a negative correlation between NS1 antibody and protein during the course of infection with antigen-antibody complexes cleared after the febrile phase.

This study aimed to investigate the role of the renin-angiotensin system (RAS) in COVID-19, particularly focusing on key components such as ACE, ACE2, and their related peptides, angiotensin-(1-7) and angiotensin-(1-9). Using serum samples from healthy controls and both non-severe and severe COVID-19 patients, ELISA assays revealed no significant differences in these RAS components between the groups. In addition, in vitro studies showed no impact of ACE inhibitors or Angiotensin Receptor Blockers (ARB) on cell viability during SARS-CoV-2 infection. These clinical findings suggest that RAS alterations may not be a major factor in COVID-19 severity and the in vitro data support current guidelines, indicating the safety of continuing ACE inhibitors and ARBs in COVID-19 patients without evidence of increased SARS-CoV-2 infectivity in the presence of these compounds. This study highlights the lack of significant changes in key RAS components during COVID-19 in a clinical cohort and provides critical in vitro evidence supporting the continued use of ACE inhibitors and ARBs in treating patients.

Background: Chikungunya virus (CHIKV) is an alphavirus spread by mosquitos that causes arthralgias and arthritis that may last for years. The objective of this study was to describe the arthritis progression and T cell immunology over a two-year period. Methods: A cohort of 40 cases of serologically confirmed CHIKV from Magdalena and Atlántico, Colombia were followed in 2019 and again in 2021. Arthritis disease severity, disability, pain, stiffness, physical function, mobility, fatigue, anxiety, sleep disturbances and depression were assessed. Serum cytokines and T-cell subsets were measured and tested for change. Correlations within each of the 2 time periods for laboratory parameters were also examined. Results: Although, arthritis disease severity, as measured by the Disease Activity Score-28 (DAS-28) did not change significantly over a two-year period, a new metric- the Chikungunya Disease Activity Score (CHIK-DAS)- was more sensitive to detect changes in disease severity than the Disease Activity Score-28 (DAS-28) and showed some improvement in average disease severity from moderate to mild over two years. Cases were characterized by moderate disability, pain, and stiffness with mild alterations of physical function, mobility, fatigue, anxiety, sleep disturbances and depression that did not change significantly over time. Small joints including the fingers and wrists were most affected without significant change over time. The percentage of effector T cells (Teffs) and regulatory T cells (Tregs) of CD4+ T cells both decreased over time. Teff percentages decreased more significantly resulting in a halving of the Teff/Treg ratio two years later. Furthermore, markers of Treg immunosuppressive function such as CTLA4, Helios, CD28, CD45RA and 41bb decreased over time. Cytokines did not change significantly over time. Conclusions: The presented data suggest that arthritis persists almost seven years after chikungunya infection in some patients with waning Teff and Treg numbers and activation markers over time. Treg activation may be a promising therapeutic target for further investigation.

Objective:Chikungunya virus is spread by mosquitos and causes a debilitating chronic arthritis that has no standard treatment to date and no specific measures of disease activity. The objective of this expert group was to develop a measure of chikungunya arthritis that would be useful for clinical trials and patient care. Methods:A group of rheumatologists and biostatisticians experienced in the clinical and pathological mechanisms of chikungunya evaluated component measures for inclusion in a chikungunya arthritis disease activity score (CHIK-DAS). Utilizing data from a Colombian cohort of 158 chikungunya arthritis patients, linear regression identified components that were independently associated with patient reported outcomes assessing disability, pain, physical and mental quality of life and mobility. A preliminary instrument was developed using multiple imputation and regression backward selection. Cutoffs for grading disease severity were determined. Results:Stiffness, ankle tenderness, and a 30 tender joint count that included the 28 joints traditionally included in the Disease Activity Score-28 were selected in a regression model predicting a composite of five patient reported outcomes. A CHIK-DAS scoring formula was developed through a weighted combination of these selected variables. In comparison to the DAS-28, the CHIK-DAS had improved predictive value for a composite outcome of disability, pain, physical and mental quality of life and mobility. Disease activity cutoffs were defined for remission (<40), mild (40-49.99), moderate (50-59.99) and severe (60+) disease. Conclusion:The CHIK-DAS is a chikungunya specific measure of disease activity that includes the DAS-28 with the addition of ankle tenderness and a stiffness item that are prominent components of chikungunya arthritis. CHIK-DAS may be used as a specific measure of disease activity in chikungunya arthritis in clinical trials and patient care. This metric needs further validation in additional cohorts.

Abstract Background With the advancement of combined antiretroviral therapy (ART), control of viral replication has improved so that most patients living with HIV (PWH) can maintain undetectable viral. However, HIV blips (defined as non-sustained detectable low-level viremia) are still commonly encountered in practice. Although these generally do not indicate treatment failure or ART resistance, their clinical significance remains a topic of debate. The aim of our study is to compare the rate of blips in patients on bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF), rilpivirine/emtricitabine/tenofovir (RPV/FTC/TAF) or dolutegravir/abacavir/lamivudine (DOL/ABC/3TC). Methods We analyzed HIV viral load (VL) data of PWH who were treated in our clinic with either BIC/FTC/TAF, RPV/FTC/TAF or DOL/ABC/3TC between 3/2017 and 10/2021 for blips. We defined low level blips as HIV VL of 51-200 copies/mL and high-level blips of201-1000 copies/mL. The incidence of blips between these regimens was examined using Chi squared test. Results A total of 324 patients were included; 138 patients on BIC/FTC/TAF, 91 patients on RPV/FTC/TAF, and 95 patients on DOL/ABC/3TC). Patients on DOL/ABC/3TC were over twice as likely to have a viral blip (36%) compared to both BIC/FTC/TAF (16%, p=.0003) and RPV/FTC/TAF (14%, p=.0004). There were no statistically significant differences between patients taking BIC/FTC/TAF or RPV/FTC/TAF. Although the DOL/ABC/3TC group had a higher rate of high-level blips (6.3%) compared to BIC/FTC/TAF (3.6%) and RPV/FTC/TAF (4.4%), the total number of patients with high blips was low (n=15) and the differences were not statistically significant. Patients on DOL/ABC/3TC had average of 8 HIV VLs checked over the study period compared to 5 for patient on RPV/FTC/TAF and 3 for patient on BIC/FTC/TAF. Conclusion Our data suggests that PWH on DOL/ABC/3TC have higher rates of blips compared to PWH on BIC/FTC/TAF or RPV/FTC/TAF. Additional studies are needed to determine if this might be due to the lack of tenofovir alafenamide in the DOL/ABC/3TC or due to increased HIV VL testing in this population. Disclosures All Authors: No reported disclosures

aDivision of Allergy and Infectious Diseases, Department of Medicine, University of Washington, Seattle bDivision of Infectious Diseases, Department of Medicine, The George Washington University School, Medicine and Health Sciences, Washington, DC, USA. Correspondence to Brian R. Wood, MD, Harborview Medical Center, 2W Clinic, 325 9th Avenue, Seattle, WA 98104, USA. E-mail: [email protected] Received 16 March, 2023 Accepted 26 March, 2023

Chikungunya virus (CHIKV) is characterized by disabling joint pain that can cause persistent arthritis in approximately one-fourth of patients. Currently, no standard treatments are available for chronic CHIKV arthritis. Our preliminary data suggest that decreases in interleukin-2 (IL2) levels and regulatory T cell (Treg) function may play a role in CHIKV arthritis pathogenesis. Low-dose IL2-based therapies for autoimmune diseases have been shown to up-regulate Tregs, and complexing IL2 with anti-IL2 antibodies can prolong the half-life of IL2. A mouse model for post-CHIKV arthritis was used to test the effects of recombinant IL2 (rIL2), an anti-IL2 monoclonal antibody (mAb), and the complex on tarsal joint inflammation, peripheral IL2 levels, Tregs, CD4 + effector T cells (Teff), and histological disease scoring. The complex treatment resulted in the highest levels of IL2 and Tregs, but also increased Teffs, and therefore did not significantly reduce inflammation or disease scores. However, the antibody group, which had moderately increased levels of IL2 and activated Tregs, resulted in a decreased average disease score. These results suggest the rIL2/anti-IL2 complex stimulates both Tregs and Teffs in post-CHIKV arthritis, while the anti-IL2 mAb increases IL2 availability enough to shift the immune environment towards a tolerogenic one.

ImportanceCurrent data identifying COVID-19 risk factors lack standardized outcomes and insufficiently control for confounders.ObjectiveTo identify risk factors associated with COVID-19, severe COVID-19, and SARS-CoV-2 infection.Design, Setting, and ParticipantsThis secondary cross-protocol analysis included 4 multicenter, international, randomized, blinded, placebo-controlled, COVID-19 vaccine efficacy trials with harmonized protocols established by the COVID-19 Prevention Network. Individual-level data from participants randomized to receive placebo within each trial were combined and analyzed. Enrollment began July 2020 and the last data cutoff was in July 2021. Participants included adults in stable health, at risk for SARS-CoV-2, and assigned to the placebo group within each vaccine trial. Data were analyzed from April 2022 to February 2023.ExposuresComorbid conditions, demographic factors, and SARS-CoV-2 exposure risk at the time of enrollment.Main Outcomes and MeasuresCoprimary outcomes were COVID-19 and severe COVID-19. Multivariate Cox proportional regression models estimated adjusted hazard ratios (aHRs) and 95% CIs for baseline covariates, accounting for trial, region, and calendar time. Secondary outcomes included severe COVID-19 among people with COVID-19, subclinical SARS-CoV-2 infection, and SARS-CoV-2 infection.ResultsA total of 57 692 participants (median [range] age, 51 [18-95] years; 11 720 participants [20.3%] aged ≥65 years; 31 058 participants [53.8%] assigned male at birth) were included. The analysis population included 3270 American Indian or Alaska Native participants (5.7%), 7849 Black or African American participants (13.6%), 17 678 Hispanic or Latino participants (30.6%), and 40 745 White participants (70.6%). Annualized incidence was 13.9% (95% CI, 13.3%-14.4%) for COVID-19 and 2.0% (95% CI, 1.8%-2.2%) for severe COVID-19. Factors associated with increased rates of COVID-19 included workplace exposure (high vs low: aHR, 1.35 [95% CI, 1.16-1.58]; medium vs low: aHR, 1.41 [95% CI, 1.21-1.65]; P < .001) and living condition risk (very high vs low risk: aHR, 1.41 [95% CI, 1.21-1.66]; medium vs low risk: aHR, 1.19 [95% CI, 1.08-1.32]; P < .001). Factors associated with decreased rates of COVID-19 included previous SARS-CoV-2 infection (aHR, 0.13 [95% CI, 0.09-0.19]; P < .001), age 65 years or older (aHR vs age <65 years, 0.57 [95% CI, 0.50-0.64]; P < .001) and Black or African American race (aHR vs White race, 0.78 [95% CI, 0.67-0.91]; P = .002). Factors associated with increased rates of severe COVID-19 included race (American Indian or Alaska Native vs White: aHR, 2.61 [95% CI, 1.85-3.69]; multiracial vs White: aHR, 2.19 [95% CI, 1.50-3.20]; P < .001), diabetes (aHR, 1.54 [95% CI, 1.14-2.08]; P = .005) and at least 2 comorbidities (aHR vs none, 1.39 [95% CI, 1.09-1.76]; P = .008). In analyses restricted to participants who contracted COVID-19, increased severe COVID-19 rates were associated with age 65 years or older (aHR vs <65 years, 1.75 [95% CI, 1.32-2.31]; P < .001), race (American Indian or Alaska Native vs White: aHR, 1.98 [95% CI, 1.38-2.83]; Black or African American vs White: aHR, 1.49 [95% CI, 1.03-2.14]; multiracial: aHR, 1.81 [95% CI, 1.21-2.69]; overall P = .001), body mass index (aHR per 1-unit increase, 1.03 [95% CI, 1.01-1.04]; P = .001), and diabetes (aHR, 1.85 [95% CI, 1.37-2.49]; P < .001). Previous SARS-CoV-2 infection was associated with decreased severe COVID-19 rates (aHR, 0.04 [95% CI, 0.01-0.14]; P < .001).Conclusions and RelevanceIn this secondary cross-protocol analysis of 4 randomized clinical trials, exposure and demographic factors had the strongest associations with outcomes; results could inform mitigation strategies for SARS-CoV-2 and viruses with comparable epidemiological characteristics.

Background To determine the effects of integrase inhibitor (INSTI) in comparison with non-INSTI-based regimens such as non-nucleoside reverse transcriptase inhibitors (NNRTIs)-based regimens on cardiovascular disease (CVD) risk in HIV+ patients without overt history of CVD or diabetes, with normal CD4:CD8 count. For CVD risk assessment we primarily used hematopoietic CD34+ progenitor cells, as a biomarker. Methods Nineteen male subjects, ages 32–61 years with BMI 21.0–36.0, were enrolled. This was a single time point, cross-sectional, observational study. Subjects were enrolled under 2 groups (either on INSTI-based regimen with 13 subjects or NNRTI (non-INSTI)-based regimens with 6 subjects) who were taking stable doses of HAART. The medication regimens were a combination of one NRTI (typically tenofovir–emtricitabine) plus one INSTI or NNRTI. Our outcome measures were focused on cardiovascular and endothelial cell function and systemic inflammation. Our primary outcome measures were peripheral blood-derived hematopoietic progenitor cell number (CD34 and CD133 positive), CD34+ cell function and gene expression studies. Our secondary outcomes were arterial stiffness measures and serum-based markers of inflammation. Results A significant increase in percentage number of progenitor cells, CD133+ cells ( p = 0.004), was noted along with an increase of double progenitor mark positive CD133+/CD34+ progenitor cell population being observed in INSTI group as compared to NNRTI group, by flow cytometry. mRNA gene expression for antioxidant gene catalase was noted along with a trend toward a decrease in gene expression of inflammatory marker IL6 ( p = 0.06) being observed in CD34+ from INSTI group vs NNRTI group. The plasma IL-6 and CRP levels did not change significantly between the groups. Neutrophil–Lymphocyte ratio (NLR), an important marker of inflammation, was noted to be lower in INSTI group. A mean fasting glucose level was also lower in the INSTI group compared to NNRTI group ( p = 0.03). Interestingly, urine microalbumin levels were higher in the INSTI group compared to NNRTI group ( p = 0.08), while eGFR levels were significantly lower in the INSTI group ( p = 0.002). The arterial stiffness measures did not show statistically significant differences between the two groups. Conclusion We conclude that the INSTI regimen may provide a better CVD risk profile compared to NNRTI-based HAART regimen; however, the increased albuminuria along with lower eGFR, noted in INSTI group, is of concern. Because of the small size, these results would need replication in additional studies before changing clinical practice. Clinical trial registration https://clinicaltrials.gov/ct2/show/NCT03782142?cond=Hiv&spons=Sabyasachi+sen&cntry=US&state=US%3ADC&city=Washington&draw=2&rank=1 . ClinicalTrials.gov Identifier: NCT03782142.

We report a case of septic polyarthritis caused by Ureaplasma urealyticum in a woman with neuromyelitis optica who was receiving rituximab. Her case exemplifies some of the unique characteristics of invasive Ureaplasma infections that can lead to delayed diagnosis as well as treatment challenges including recurrence following antibiotic discontinuation.

PROBLEM:HIV/AIDS and sexual violence act synergistically and compromise women's health. Yet, immuno-biological mechanisms linking sexual violence and increased HIV susceptibility are poorly understood.METHODS:We conducted a cross-sectional pilot study of HIV-uninfected women, comparing 13 women exposed to forced vaginal penetration within the past 12 weeks (Exposed) with 25 Non-Exposed women. ELISA assays were conducted for 49 biomarkers associated with HIV pathogenesis in plasma and cervicovaginal lavage (CVL). Differences between Exposed and Non-Exposed were analyzed by linear and logistic regression, using propensity score weighting to control for age, race, socioeconomic status, menstrual cycle, and contraceptive use.RESULTS:In CVL, Exposed women had significantly reduced chemokines MIP-3α (p < .01), MCP-1 (p < .01), and anti-HIV/wound-healing thrombospondin-1 (p = .03). They also had significantly increased inflammatory cytokine IL-1α (p < 0.01) and were more likely to have detectable wound-healing PDGF (p = .02). In plasma, Exposed women had reduced chemokines MIP-3α (p < .01) and IL-8 (p < .01), anti-inflammatory cytokine TGF-β (p = .02), anti-HIV/antimicrobial HBD-2 (p = .02), and wound-healing MMP-1 (p = 0.02). They also had increased thrombospondin-1 (p < .01) and Cathepsin B (p = .01). After applying the stringent method of false discovery rate adjustment, differences for IL-1α (p = .05) and MCP-1 (p = .03) in CVL and MIP-3α (p = .03) in plasma remained significant.CONCLUSIONS:We report systemic and mucosal immune dysregulation in women exposed to sexual violence. As these biomarkers have been associated with HIV pathogenesis, dysregulation may increase HIV susceptibility.

Chronic rheumatological manifestations similar to those of rheumatoid arthritis (RA) are described after chikungunya virus infection. We aimed to compare the relevance of joint counts and symptoms to clinical outcomes in RA and chronic chikungunya disease. Forty patients with chronic chikungunya arthralgia and 40 patients with RA were enrolled in a cross-sectional study. The association of tenderness and swelling, clinically assessed in 28 joints, and patient evaluations of pain and musculoskeletal stiffness with modified Health Assessment Questionnaire (HAQ) and quality of life (QoL) assessments were investigated. Tender and swollen joint counts, pain and stiffness scores were all associated with the HAQ disability index in RA (all r > 0.55, p ≤ 0.0002), but only stiffness was significantly associated with disability in chikungunya (r = 0.38, p = 0.02). Joint counts, pain and stiffness were also associated with most QoL domains in RA patients. In contrast, in chikungunya disease, tender joint counts were associated only with one QoL domain and swollen joints for none, while pain and stiffness were associated with several domains. Our results confirm the relevance of joint counts in RA, but suggest that in chronic chikungunya disease, joint counts have more limited value. Stiffness and pain score may be more important to quantify chikungunya arthritis impact.

Persistent joint pain is a common manifestation of arthropod-borne viral infections and can cause long-term disability. We review the epidemiology, pathophysiology, diagnosis, and management of arthritogenic alphavirus infection. The global re-emergence of alphaviral outbreaks has led to an increase in virus-induced arthralgia and arthritis. Alphaviruses, including Chikungunya, O’nyong’nyong, Sindbis, Barmah Forest, Ross River, and Mayaro viruses, are associated with acute and/or chronic rheumatic symptoms. Identification of Mxra8 as a viral entry receptor in the alphaviral replication pathway creates opportunities for treatment and prevention. Recent evidence suggesting virus does not persist in synovial fluid during chronic chikungunya infection indicates that immunomodulators may be given safely. The etiology of persistent joint pain after alphavirus infection is still poorly understood. New diagnostic tools along and evidence-based treatment could significantly improve morbidity and long-term disability.

Chikungunya virus (CHIKV) was introduced to the Americas in 2013, causing two million infections across over thirty countries. CHIKV causes a chronic debilitating arthritis in one fourth of infected individuals and currently evidence-based targeted therapies for the treatment of CHIKV arthritis are lacking. Multiple mouse models of chikungunya have been developed to study acute CHIKV infection. In humans, post-CHIKV arthritis may persist for months to years after viremia from a CHIKV infection has resolved. Therefore, the development of a mouse model of post-acute arthritis of chikungunya may facilitate the study of potential novel therapeutics for this arthritis. In this article we describe the development of a wild-type immunocompetent C57BL/6 mouse model for post-acute arthritis of chikungunya, including a histologic inflammation scoring system, as well as suggestions for how this mouse model may be used to examine the efficacy of novel therapies for CHIKV arthritis.

We present a case of polymicrobial subacute bacterial endocarditis and bacteremia with Bacillus cereus and Cardiobacterium hominis in a 72-year-old man with pre-existing mitral valve disease and prior mitral valve repair who presented with renal failure and glomerulonephritis. Bacillus is often a contaminant in blood cultures but has been rarely implicated in patients with invasive infections such as endocarditis. Intravenous drug use, prosthetic heart valves, valvular heart disease and venous catheters are the most frequently described risk factors for Bacillus bacteremia and endocarditis in the medical literature. Management is challenging as Bacillus is resistant to penicillin and cephalosporin antibiotics due to production of beta-lactamase. Polymicrobial endocarditis is uncommon and when it occurs typically involves Staphylococcal species. To our knowledge, this is the first reported case of polymicrobial endocarditis in which both Bacillus and a HACEK organism are implicated.