HIV Antibody Research Articles

EXTENSIVE PNEUMATOCELES DUE TO PNEUMOCYSTIS JIROVECI PNEUMONIA IN A PATIENT NEWLY DIAGNOSED WITH HIV INFECTION

EXTENSIVE PNEUMATOCELES DUE TO PNEUMOCYSTIS JIROVECI PNEUMONIA IN A PATIENT NEWLY DIAGNOSED WITH HIV INFECTION

TB DURING THE SEROCONVERSION PHASE

TB DURING THE SEROCONVERSION PHASE

S1896 A Rare Case of Strongyloides Cholangitis With Portal Vein Thrombus and Recurrent Intra-Abdominal Abscesses

Introduction: Strongyloides stercoralis infection outside of the gastrointestinal tract is extremely uncommon, particularly in an immunocompetent host. We present a rare case of S. stercoralis cholangitis complicated by portal vein thrombus and recurrent intra-abdominal abscesses in an immunocompetent patient. Case Description/Methods: A 65-year-old male who immigrated to the United States (US) over 40 years prior from Nigeria, presented with 4 days of epigastric pain, weakness, fevers and anorexia. His medical history was notable for COPD and an intra-abdominal abscess two years prior. His previous abscess was treated with percutaneous drainage and antibiotics. On arrival, he was afebrile and tachycardic to 110 bpm. He appeared jaundiced, and his abdomen was distended with right upper quadrant tenderness. Labs showed AST 121 IU/L, ALT 263 IU/L, ALP 267 IU/L, total bilirubin 8.3 mg/dL (direct 5.4 mg/dL), WBC 13.6 K/uL, eosinophils 0.28 K/uL. Non-contrast-enhanced abdominal computerized tomography (CT) scan showed an 8.4 cm subdiaphragmatic collection adjacent to the gastric fundus and intra- and extrahepatic ductal dilation. MRCP showed luminal irregularity of the common bile duct with multiple areas of stenosis of intra- and extrahepatic bile ducts and cavernous transformation of a chronic portal vein thrombus. Aspirates of the sub-diaphragmatic fluid collection and blood cultures grew Pseudomonas aeruginosa. Intravenous piperacillin-tazobactam was started. Upper endoscopy and endoscopic ultrasound of the stomach showed normal gastric and duodenal mucosa with multiple large periduodenal varices. Duodenal biopsies revealed Strongyloides species (Figure ). S. stercoralis serologies were positive and HIV antibodies were negative. He underwent surgical washout of the abdominal abscess and was treated with 2 weeks of oral ivermectin and ciprofloxacin. Discussion: S.stercoralis transmission occurs when human skin contacts the infective larvae. Carriers may remain asymptomatic for decades. Symptoms can include pruritus, diarrhea, weight loss and abdominal pain. Complications such as biliary tree invasion and portal vein thrombus are rare but have been reported. Deposition of eggs in the bowel wall can lead to bacterial gut translocation, gram negative sepsis and recurrent abscesses. Disseminated strongyloidiasis typically occurs in the setting of immunosuppression, HIV, or hematologic malignancies and rarely occurs in an immunocompetent host. Diagnosis can be challenging.Figure 1.: Strongyloides organism on duodenal biopsy.

INVESTIGATIONS OF CHRONIC HEPATITIS B and C IN HIV-INFECTION

Relevance. Today, there are controversies regarding the influence of hepatitis B and C viruses on the course of HIV infection.
 Objective assess the course and outcomes of chronic hepatitis B and C in HIV-infected patients, as well as to analyze the causes of death of such patients.
 Materials and methods. A retrospective pseudorandomized study was conducted with a depth of 5 years. 114 medical records of inpatients (HIV infection in association with hepatitis B and C) were selected. The analysis of the causes of death in patients with HIV infection was carried out based on the study of autopsy materials of 21 patients.
 Results. It was established that the frequency of CHV exacerbation in III-IV clinical stages of HIV infection is significantly higher, and remission is lower than in I-II stages - (36.8±4.5) versus (7.0±2.4)% and (35.1±4.5) and (7.9±2.5)%, respectively (p<0.001). The frequency of liver cirrhosis was characterized by a clear tendency to increase with the deepening of immunodeficiency.
 The calculation of the frequency of findings in liver cirrhosis showed that in the I-II clinical stage of HIV infection, this value was equal to 0.17, and in the III-IV stage - 0.33. The relative risk of developing liver cirrhosis in HIV-infected patients was 0.52. Moreover, the probability of a fatal outcome in cirrhosis of the liver in HIV-infected patients in the I-II clinical stage was equal to 0.16, and in the III-IV stage - 0.29, with a relative risk of 0.63. The reduction in the relative risk of a fatal outcome taking into account the stage of HIV infection is 0.32.
 The average life expectancy of patients from the moment of detection of HIV antibodies was (3.4±0.6) years (from 4 months to 9 years). Such a short average life expectancy of HIV-infected patients was caused by a large number of patients diagnosed for the first time already in the IV clinical stage. In more than half (13 out of 21) the causes of death were AIDS-related diseases (61.9 %).
 Conclusions. A retrospective pseudorandomized study showed that cirrhosis of the liver in the early stages of HIV infection was registered 2.7 times less often than in patients with HIV infection in the stage of secondary diseases.
 Exacerbation of chronic hepatitis B and C is significantly more often established in the III-IV clinical stage of concomitant HIV infection. Under the same circumstances, signs of cirrhosis of the liver are more often registered, and fatal outcomes occupy one of the leading places in patients with HIV infection. This indicates the need to revise the tactics of clinical management of this category of patients.
 In 61.9 % of cases, the causes of death were AIDS-indicative diseases. Tuberculosis turned out to be the leading cause of death (46.1 %) of HIV-infected patients and was mainly in a generalized form. Toxoplasmosis (30.8 %) with damage to the brain and other organs takes the second place in terms of the frequency of fatal AIDS-indicative diseases. Meningoencephalitis of unspecified (probably herpetic) etiology was found in 23.1 % of the deceased. An important place in the structure of fatal outcomes in HIV-infected patients is occupied by the terminal stage of cirrhosis of the liver of mixed etiology - viral and alcoholic (38.1 %).

Seroprevalence of Toxoplasma gondii in people at an increased risk of HIV infection – a pilot study

<br><b>Introduction:</b> The observation of the epidemiology of toxoplasmosis may prevent the development of a severe form of the disease in HIV patients.</br> <br><b>Aim:</b> The aim of the study was to evaluate the seroprevalence of <i>Toxoplasma gondii</i> in the population of the Kuyavian-Pomeranian Voivodeship at high risk of contracting HIV.</br> <br><b>Material and methods:</b> Blood serum samples of 43 patients of the Consulting and Diagnostic AIDS Center were tested for the presence of anti-HIV-1/HIV-2 antibodies and p24 antigen, and for the presence of anti-toxoplasma IgM and IgG antibodies.</br> <br><b>Results:</b> Anti-toxoplasma IgG antibody prevalence of 53.5% (23/43) was found in the study population, while the examination of specific IgM antibodies was negative. A high IgG antibody avidity index was obtained in 18 (94.7%) seropositive samples. Thirty (69.77%) of the samples were female, and 13 (30.23%) were male. Among men, HIV was detected in 1 (7.69%), and IgG antibodies against <i>T. gondii</i> in 7 (53.85%) samples. IgG antibodies against <i>T. gondii</i> were found in 16 (53.33%) women. The HIV-positive individual was 24 years old. The presence of antibodies against <i>T. gondii</i> in the IgG class was found in people of different ages (in women aged 38.44 ±13.00 years old and in men aged 29.29 ±10.86 years old). The risky situation that could cause HIV infection is in most cases sexual contacts (79.07%).</br> <br><b>Conclusions:</b> High seroprevalence of <i>T. gondii</i> was found among the studied subjects at a high risk of HIV infection. Further research is required on a larger study group.</br>

AIRRscape: An interactive tool for exploring B-cell receptor repertoires and antibody responses.

The sequencing of antibody repertoires of B-cells at increasing coverage and depth has led to the identification of vast numbers of immunoglobulin heavy and light chains. However, the size and complexity of these Adaptive Immune Receptor Repertoire sequencing (AIRR-seq) datasets makes it difficult to perform exploratory analyses. To aid in data exploration, we have developed AIRRscape, an R Shiny-based interactive web browser application that enables B-cell receptor (BCR) and antibody feature discovery through comparisons among multiple repertoires. Using AIRR-seq data as input, AIRRscape starts by aggregating and sorting repertoires into interactive and explorable bins of germline V-gene, germline J-gene, and CDR3 length, providing a high-level view of the entire repertoire. Interesting subsets of repertoires can be quickly identified and selected, and then network topologies of CDR3 motifs can be generated for further exploration. Here we demonstrate AIRRscape using patient BCR repertoires and sequences of published monoclonal antibodies to investigate patterns of humoral immunity to three viral pathogens: SARS-CoV-2, HIV-1, and DENV (dengue virus). AIRRscape reveals convergent antibody sequences among datasets for all three pathogens, although HIV-1 antibody datasets display limited convergence and idiosyncratic responses. We have made AIRRscape available as a web-based Shiny application, along with code on GitHub to encourage its open development and use by immuno-informaticians, virologists, immunologists, vaccine developers, and other scientists that are interested in exploring and comparing multiple immune receptor repertoires.

O-07: TRANSFUSION PRACTICE, POST-TRANSFUSION COMPLICATIONS AND RISK FACTORS IN SICKLE CELL DISEASE IN SENEGAL

Purpose: Blood transfusion is an indispensable therapy in sickle cell disease, despite its multiple and often harmful complications. The objective of this study was to evaluate the complications of alloimmunization, infection and iron overload secondary to blood transfusion in sickle cell disease patients. Materials and methods: This was a six-month cross-sectional case-control study conducted in the Clinical Hematology Department of Dakar (Senegal) on 253 patients followed for major sickle cell disease (153 polytransfused and 100 non-transfused patients). Transfusion practice (modalities, indications), post-transfusion complications (alloimmunization, iron overload, infections) and risk factors (sociodemographic, clinical, biological) for the occurrence of these complications were evaluated. Results: The median age of the patients was 28.5 years (5-59). The sex ratio (M/F) was 0.86. Homozygous sickle cell disease was more frequent (95.3%). The median follow-up time was 9.1 years (2-26). Simple transfusion was performed in 142 patients, exchange transfusion in 29 patients; 22 patients were on a transfusion program. The indications for transfusion were dominated by acute anemia (57.06%) and prolonged CVO (14%). Red blood cell concentrates were administered in 143 patients (93.46%). The median number of units of blood received per patient was 10 units (2 - 48). The frequency of alloimmunization was 16% and the most frequent alloantibodies were anti-rhesus (34.19%) and anti-Kell (23.67%). The prevalence of hepatitis C in transfused subjects was 1.33% and 1% in non-transfused subjects (p=0.64). The prevalence of HBV was 2% in transfused patients and 3% in non-transfused patients (p=0.45). HIV antibodies were not found in either the transfused or the non-transfused patients. Twelve patients (7.84%) had post-transfusion iron overload (ferritin level >1000 ng/ml). The higher the transfusion, the higher the ferritin level (strong positive correlation, r = 0.8). The number of packed red blood cells transfused was the only risk factor for alloimmunization (p=0.03) and post-transfusion iron overload (p=0.023). The frequency of blood transfusion was not related to the transmission of infectious. Conclusion: The management of sickle cell disease often requires blood transfusion to correct anemia or prevent certain complications. Despite the progress made in transfusion safety, this therapy still remains a risk for the recipient. The authors do not declare any conflict of interest

Determining the Prevalence of Hepatitis Delta Virus, Hepatitis C Virus, and HIV Among Mothers and Infants with Hepatitis B Virus Chronic Infection

Background: Infection with hepatitis B, C, and delta viruses (HBV/HCV/HDV) caused by mother-to-child transmission (MTCT) is still a serious health problem worldwide. Coinfection with HBV/HDV or HCV has been shown to accelerate the progression of chronic HBV infection, resulting in higher mortality. Objectives: The aim of this study was to evaluate the prevalence of anti-HCV, anti-HDV, and anti-HIV antibodies in mothers with chronic HBV infection and their infants. Methods: This cross-sectional study was performed on 100 mothers with chronic HBV (hepatitis B surface antigen-positive [HBsAg+]/hepatitis B core antibody-positive [HBcAb+]) and their infants between 2020 and 2021 in northeastern Iran. The presence of serological markers of HBV, anti-HCV, anti-HDV, and HIV antibodies, as well as the liver function tests, were evaluated in all mothers. The obtained data were analyzed using SPSS version 20, and the level of the statistical significance was set at a P-value < 0.05. Results: The mean age in all individuals was 37.45 ± 17.95 years. In mothers with chronic HBV and their infants, 3, 11, and 15% were serologically positive for anti-HCV, HCV/HDV, and anti-HDV, respectively. Also, all participants were serologically negative for anti-HIV. A statistical analysis showed a significant correlation of anti-HDV (95% CI, 0.113 - 0.332) with education, place of residence, and anti-HCV (95% CI, 0.313 - 0.416) in mothers with chronic HBV. The percentages of mothers and infants with simultaneous infection HBV were reported to be 1, 2, and 1% when anti-HCV, anti-HDV, and anti-HCV/HDV antibodies were measured, respectively. Conclusions: Intellectual strategies in the diagnosis of HCV, HIV, and HDV in patients with chronic HBV have challenged public and global health, and preventing viral infections in newly born infants is the most effective way to control the HBV/HCV or HDV epidemic.

Development of Recombinant Immunoblot Assay Diagnostic Test Based on HIV-1 in Indonesia

Background: High mutation rates in HIV-1 could affect the accuracy of diagnostic tests. Therefore, recombinant antigen that has an immunodominant and conserved region from HIV-1 need to be developed to detect HIV-1 infection in Indonesia.Materials and methods: The recombinant antigens comprise of Gag (p24), Pol and Env (gp41). Each antigens was expressed in the Escherichia coli expression system and purified using Ni-NTA chromatography. The reactivity of purified antigen against HIV antibodies was tested against a group of 50 HIV-positive plasma samples and 45 HIV-negative plasma samples in a recombinant immunoblot assay (RIBA) platform test. Moreover, 21 of 50 HIV-positive samples and 3 of 45 HIV-negative samples were also tested using HIV blot 2.2 to compare RIBA with a commercial western blot kit. Ten HBV-positive and 10 HCV-positive plasma samples were used to check cross-reactivity with HIV recombinant proteins in RIBA.Results: All HIV-positive samples (100%) tested with RIBA were reactive towards Gag (p24), Pol, Env (gp41). Otherwise, 3 of 21 HIV-positive samples assayed with HIV blot 2.2 were not reactive to Pol protein. All HIV-negative samples tested with RIBA and 3 HIV-negative samples tested with HIV blot 2.2 did not produce any bands of HIV antigens. Few HBV and HCV samples showed reactivity towards HIV recombinant proteins.Conclusion: Each recombinant protein, Gag (p24), Pol, Env (gp41), could be expressed and purified, as well as had reactivity to HIV-positive samples in RIBA test. Therefore, RIBA can be used as a diagnostic test to detect HIV-1 infection in Indonesia.Keywords: diagnostic, HIV-1, immunodominant, recombinant immunoblot assay (RIBA)

Evaluation of the Geenius HIV 1/2 confirmatory assay for HIV-2 samples isolated in Japan.

Although the number of HIV-2-infected individuals is quite low in Japan, at least three groups of HIV-2 (A, B and CRF01_AB) have been detected thus far. In particular, CRF01_AB HIV-2 cases have been found only in limited areas, Cote d'Ivoire and Japan. Here, we demonstrate that Geenius HIV 1/2 Confirmatory Assay (Geenius, Bio-Rad Laboratories) is able to detect HIV-2 samples, including groups A, B and CRF01_AB, isolated in Japan. A total of 57 plasma samples, including three panels (Ⅰ: HIV-2-positive samples [n=9], Ⅱ: HIV-1 infection with HIV-2 antibody cross-reactivity samples [n=37], and Ⅲ: HIV negative with biological false-positive HIV-2 samples [n=11]) were tested by Geenius. Geenius determined Panel I to be "HIV-2 positive with/without HIV-1 cross-reactivity (n=4, respectively)", including HIV-2 group A and CRF01_AB. In the case with HIV-2 group B, all bands were detected, resulting in a Geenius interpretation of "HIV positive untypable". Geenius classified Panels II and III as "HIV-1 positive (n=37)" or "HIV negative (n=9)", "HIV indeterminate (n=1)" and "HIV-2 indeterminate (n=1)", suggesting 95.8% HIV-2 differentiation by Geenius. With Geenius, there were fewer false-positives for HIV-1/-2 negativity and fewer cross-reactions with HIV-2 among HIV-1-positive samples. Additionally, the assay could detect HIV-2 genetic group CRF01_AB. Geenius can be expected to be a useful diagnostic tool that is an alternative to conventional Western blotting.

Vaccine-Induced Seroreactivity Impacts the Accuracy of HIV Testing Algorithms in Sub-Saharan Africa: An Exploratory Study.

The detection of vaccine-induced HIV antibody responses by rapid diagnostic tests (RDTs) may confound the interpretation of HIV testing results. We assessed the impact of vaccine-induced seroreactivity (VISR) on the diagnosis of HIV in sub-Saharan Africa. Samples collected from healthy participants of HIVIS and TaMoVac HIV vaccine trials after the final vaccination were analyzed for VISR using HIV testing algorithms used in Mozambique and Tanzania that employ two sequential RDTs. The samples were also tested for VISR using Enzygnost HIV Integral 4 ELISA and HIV western blot assays. Antibody titers to subtype C gp140 were determined using an in-house enzyme-linked immunosorbent assay (ELISA). The frequency of VISR was 93.4% (128/137) by Enzygnost HIV Integral 4 ELISA, and 66.4% (91/137) by western blot assay (WHO interpretation). The proportion of vaccine recipients that would have been misdiagnosed as HIV-positive in Mozambique was half of that in Tanzania: 26.3% (36/137) and 54.0% (74/137), respectively, p < 0.0001. In conclusion, the HIV RDTs and algorithms assessed here will potentially misclassify a large proportion of the HIV vaccine recipients if no other test is used. Increased efforts are needed to develop differential serological or molecular tools for use at the point of care.

Brief Report: Adolescent Girls Who Sell Sex in Zimbabwe: HIV Risk, Behaviours, and Service Engagement.

To reduce HIV incidence among adolescent girls who sell sex (AGSS) in Zimbabwe, we need to better understand how vulnerabilities intersect with HIV infection and how those living with HIV engage in care. In 2017, we conducted social mapping in 4 locations in Zimbabwe and recruited girls aged 16-19 years who sell sex, using respondent-driven sampling or census sampling methods. Participants completed a questionnaire and provided finger prick blood samples for HIV antibody testing. Of 605 AGSS recruited, 74.4% considered themselves sex workers, 24.4% reported experiencing violence in the past year, 91.7% were not in school, and 83.8% had less than a complete secondary education. Prevalence of HIV increased steeply from 2.1% among those aged 16 years to 26.9% among those aged 19 years; overall, 20.2% of AGSS were HIV-positive. In the multivariate analysis, age, education, marital status, and violence from a client were associated with HIV. Among the 605 AGSS, 86.3% had ever tested for HIV, with 64.1% having tested in the past 6 months. Among AGSS living with HIV, half (50.8%) were aware of their status, among whom 83.9% reported taking antiretroviral therapy. The steep rise in HIV prevalence among those aged between 16 and 19 years suggests the window to engage with AGSS before HIV acquisition is short. To accelerate reductions in incidence among AGSS, intensified combination prevention strategies that address structural factors and tailor services to the needs of AGSS are required, particularly ensuring girls enroll and remain in school.

The Impact of Early Antiretroviral Treatment (ART) for HIV on the Sensitivity of the Latest Generation of Blood Screening and Point of Care Assays.

Introduction: Rapid initiation of antiretroviral therapy (ART) in early HIV infection is important to limit seeding of the viral reservoir. A number of studies have shown that if ART is commenced prior to seroconversion, the seroconversion may, or may not, occur. We aimed to assess whether seroreversion or no seroconversion occurs using samples collected during an early treatment study in South Africa. Methods: We tested 10 longitudinal samples collected over three years from 70 blood donors who initiated ART after detection of acute or early HIV infection during donation screening on fourth- and fifth-generation HIV antibody and RNA assays, and three point of care (POC) rapid tests. Donors were allocated to three treatment groups: (1) very early, (2) early, and (3) later. Longitudinal samples were grouped into time bins post-treatment initiation. Results: On all three high-throughput HIV antibody assays, no clear pattern of declining signal intensity was observed over time after ART initiation in any of the treatment initiation groups and 100% detection was obtained. The Abbott Determine POC assay showed 100% detection at all time points with no seroreversion. However, the Abbott ABON HIV1 and OraSure OraQuick POC assays showed lower proportions of detection in all time bins in the very early treated group, ranging from 50.0% (95% CI: 26.8–73.2%) to 83.1% (95% CI: 64.2–93.0%), and moderate detection rates in the early and later-treated groups. Conclusion: While our findings are generally reassuring for HIV detection when high-throughput serological screening assays are used, POC assays may have lower sensitivity for detection of HIV infection after early treatment. Findings are relevant for blood safety and other settings where POC assays are used.

No evidence that circulating HIV-specific immune responses contribute to persistent inflammation and immune activation in persons on long-term ART.

People with HIV (PWH) have persistently elevated levels of inflammation and immune activation despite suppressive antiretroviral therapy (ART), with specific biomarkers showing associations with non-AIDS-defining morbidities and mortality. We investigated the potential role of the HIV-specific adaptive immune response, which also persists under ART, in driving levels of these clinically relevant biomarkers. Cohort-based study. HIV-specific IFN-γ-producing T-cell responses and antibody concentrations were measured in blood at study entry in the ACTG A5321 cohort, following a median of 7 years of suppressive ART. HIV persistence measures including cell-associated (CA)-DNA, CA-RNA, and plasma HIV RNA (single-copy assay) were also assessed at study entry. Plasma inflammatory biomarkers and T-cell activation and cycling were measured at a pre-ART time point and at study entry. Neither the magnitudes of HIV-specific T-cell responses nor HIV antibody levels were correlated with levels of the inflammatory or immune activation biomarkers, including hs-CRP, IL-6, neopterin, sCD14, sCD163, TNF-α, %CD38 + HLA-DR + CD8 + and CD4 + cells, and %Ki67 + CD8 + and CD4 + cells - including after adjustment for pre-ART biomarker level. Plasma HIV RNA levels were modestly correlated with CD8 + T-cell activation ( r = 0.25, P = 0.027), but other HIV persistence parameters were not associated with these biomarkers. In mediation analysis, relationships between HIV persistence parameters and inflammatory biomarkers were not influenced by either HIV-specific T-cell responses or antibody levels. Adaptive HIV-specific immune responses do not appear to contribute to the elevated inflammatory and immune activation profile in persons on long-term ART.

Evaluation of the bioMérieux VIDAS HIV Duo Quick and Anti-HCV assays for dried blood spot based serosurveillance

Serosurveillance is central to monitoring our progress towards HIV and HCV elimination targets proposed for 2030. However, serosurveillance systems are ineffective without reliable serological assays for the detection of HIV and HCV antibodies. Assays should also be compatible with dried blood spot (DBS) samples to facilitate biological sample collection. The VIDAS HIV Duo Quick and Anti-HCV assays are sold as reagents strips and processed by the automated VIDAS benchtop immunoanalyser. While both assays have shown excellent performance in serum and plasma, performance data in DBS samples is lacking. In our study, we evaluate the performance of the VIDAS HIV Duo Quick and Anti-HCV assays in DBS (n = 725) collected during a cross-sectional serosurvey (the Transitions study). The VIDAS HIV Duo quick had a sensitivity and specificity of 94.5% (95% CI 85.1%, 98.5%) and 95.7% (95% CI 93.9%, 97.0%) respectively. Likewise, the VIDAS Anti-HCV had a sensitivity and specificity of 95.6% (95% CI 91.6%, 97.8%) and 95.6% (95% CI 93.5%, 97.0%) respectively. These assays are unlikely to be helpful in low-prevalence settings due to sub-optimal performance, but their performance could likely be improved by optimizing DBS elution protocols which was, unfortunately, not possible during our study.

How to decrease systemic corticosteroids in pemphigus patients under rituximab.

How to decrease systemic corticosteroids in pemphigus patients under rituximab.

PrEP use and unmet PrEP-need among men who have sex with men in London prior to the implementation of a national PrEP programme, a cross-sectional study from June to August 2019

BackgroundAccess to prevention options, including HIV pre-exposure prophylaxis (PrEP), remains a public health priority for gay, bisexual, and other men who have sex with men (MSM), especially in London. We describe PrEP use in a London community sample of MSM before the introduction of a national PrEP programme in October 2020.MethodsFrom June–August 2019, MSM aged ≥ 18 recruited from London commercial venues were asked to self-complete a sexual health questionnaire and provide an oral fluid sample for anonymous HIV antibody testing. Descriptive analyses of demographic characteristics, service engagement and outcomes, as well as sexual risk and prevention behaviours were examined in the survey population and in those reporting current PrEP use. We performed sequential, multivariate analyses examining current PrEP use in MSM of self-perceived HIV-negative/unknown status with identified PrEP-need defined as the report of condomless anal sex (CAS) in the last three months, or the report of CAS (in the last year) with an HIV-positive/unknown status partner not known to be on HIV treatment, in reflection of UK PrEP guidelines.ResultsOne thousand five hundred and thirty-fifth questionnaires were completed across 34 venues, where 1408 were analysed. One in five MSM of self-perceived HIV-negative/unknown status reported current PrEP use (19.7%, 242/1230). In men with PrEP-need, 68.2% (431/632) did not report current use. Current PrEP use was associated with age (aOR: 3.52, 95% CI: 1.76–7.02 in men aged 40–44 vs men aged 18–25) and education (aOR: 1.72, 95% CI: 1.01–2.92 in men with ≥ 2 years/still full-time vs no/ < 2 years of education since age 16).ConclusionAmong MSM in London, PrEP use is high but there is indication of unmet PrEP-need in men of younger age and lower levels of post-16 education. National programme monitoring and evaluation will require continued community monitoring to guide interventions ensuring equitable PrEP access and uptake in those who could most benefit from PrEP.

Factors Associated With Newly HIV Infection and Transmitted Drug Resistance Among Men Who Have Sex With Men in Harbin, P.R. China

BackgroundThis study aimed to evaluate HIV incidence, factors associated with HIV incidence and transmitted drug resistance (TDR) among newly infected men who have sex with men (MSM) in Harbin, P.R. China.MethodsA cohort study was conducted among MSM in Harbin during 2013 and 2018, with a follow-up frequency of every 6 months. Blood samples from MSM were tested for HIV antibodies, RNA was extracted from plasma, and the pol gene was sequenced, and genotypic drug-resistance analyses were performed.ResultsFrom 2013 to 2018, the overall rate of HIV incidence was 3.55/100 PY. Syphilis infection, unprotected sex with men in the past 6 months, and unawareness of HIV/AIDS knowledge were risk factors for HIV seroconversion. The distribution of HIV genotypes was as follows: CRF01_AE, 57.1%; CRF07_BC, 28.5%; CRF55_01B, 2.0%; B, 8.2%. The prevalence of transmitted drug resistance was 4.08%.ConclusionHIV incidence in MSM in Harbin is moderately high, and transmitted drug resistance exists in the population.

B cells expressing IgM B cell receptors of HIV-1 neutralizing antibodies discriminate antigen affinities by sensing binding association rates.

HIV-1 envelope (Env) proteins designed to induce neutralizing antibody responses allow study of the role of affinities (equilibrium dissociation constant [KD]) and kinetic rates (association/dissociation rates) on B cell antigen recognition. It is unclear whether affinity discrimination during B cell activation is based solely on Env protein binding KD and whether B cells discriminate among proteins of similar affinities that bind with different kinetic rates. Here, we use a panel of Env proteins and Ramos B cell lines expressing immunoglobulin M (IgM) B cell receptors (BCRs) with specificity for CD4-binding-site broadly neutralizing antibodies to study the role of antigen binding kinetic rates on both early (proximal/distal signaling) and late events (BCR/antigen internalization) in B cell activation. Our results support a kinetic model for B cell activation in which Env protein affinity discrimination is based not on overall KD but on sensing of association rate and a threshold antigen-BCR half-life.

Aanalysis of Western blot band patterns in HIV-1 antibody positive cases

Aanalysis of Western blot band patterns in HIV-1 antibody positive cases