Genetic Associations Between Modifiable Risk Factors and Alzheimer Disease.

Importance: An estimated 40% of dementia is potentially preventable by modifying 12 risk factors throughout the life course. However, robust evidence for most of these risk factors is lacking. Effective interventions should target risk factors in the causal pathway to dementia. Objective: To comprehensively disentangle potentially causal aspects of modifiable risk factors for Alzheimer disease (AD) to inspire new drug targeting and improved prevention. Design, Setting, and Participants: This genetic association study was conducted using 2-sample univariable and multivariable mendelian randomization. Independent genetic variants associated with modifiable risk factors were selected as instrumental variables from genomic consortia. Outcome data for AD were obtained from the European Alzheimer & Dementia Biobank (EADB), generated on August 31, 2021. Main analyses were conducted using the EADB clinically diagnosed end point data. All analyses were performed between April 12 and October 27, 2022. Exposures: Genetically determined modifiable risk factors. Main Outcomes and Measures: Odds ratios (ORs) and 95% CIs for AD were calculated per 1-unit change of genetically determined risk factors. Results: The EADB-diagnosed cohort included 39 106 participants with clinically diagnosed AD and 401 577 control participants without AD. The mean age ranged from 72 to 83 years for participants with AD and 51 to 80 years for control participants. Among participants with AD, 54% to 75% were female, and among control participants, 48% to 60% were female. Genetically determined high-density lipoprotein (HDL) cholesterol concentrations were associated with increased odds of AD (OR per 1-SD increase, 1.10 [95% CI, 1.05-1.16]). Genetically determined high systolic blood pressure was associated with increased risk of AD after adjusting for diastolic blood pressure (OR per 10-mm Hg increase, 1.22 [95% CI, 1.02-1.46]). In a second analysis to minimize bias due to sample overlap, the entire UK Biobank was excluded from the EADB consortium; odds for AD were similar for HDL cholesterol (OR per 1-SD unit increase, 1.08 [95% CI, 1.02-1.15]) and systolic blood pressure after adjusting for diastolic blood pressure (OR per 10-mm Hg increase, 1.23 [95% CI, 1.01-1.50]). Conclusions and Relevance: This genetic association study found novel genetic associations between high HDL cholesterol concentrations and high systolic blood pressure with higher risk of AD. These findings may inspire new drug targeting and improved prevention implementation.

Low rate of vaccination and risk of incident hepatitis A among HIV-infected men who have sex with men in Seville, Southern Spain.

BACKGROUND: Periodic outbreaks of hepatitis A (HAV) infection in men who have sex with men (MSM) have been reported. Low vaccination uptake in HIV-infected individuals could drive new outbreaks. We aimed at evaluating the incidence of and risk factors for HAV infection in people living with HIV (PLWH) in our area. We also assessed the rates of HAV vaccination. METHODS: This was a prospective cohort study. 915 patients were included, 272 (30%) of them were anti-HAV seronegative at baseline. RESULTS: Twenty-six (9.6%) susceptible individuals became infected. Incident cases peaked in 2009-2010 and 2017-2018. Incident HAV infection was independently associated with MSM [adjusted odds ratio (95% confidence ratio): 4.39 (1.35-14.27), p=0.014]. One hundred and five (38.6%) HAV seronegative patients were vaccinated, 21 (20%) of them did not respond, and one (1%) patient lost immunity against HAV. Four (29%) non-responders to vaccination showed incident HAV 5-9 years afterwards. CONCLUSIONS: The incidence of HAV infection in a cohort of well-controlled PLWH remains low and stable, with intermittent outbreaks involving mainly non-immunized MSM. A significant proportion of PLWH remain susceptible to HAV infection due to insufficient vaccine uptake and limited response to vaccination. Importantly, patients not responding to HAV vaccination continue at risk of infection.

Reduced neutralizing antibody response to SARS-CoV-2 vaccine booster dose in people living with HIV with severe immunosuppression.

The aim of this study was to assess the immunogenicity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines among people living with HIV (PLWH) with severe immunosuppression, after a booster dose. The design was a case-control study nested in a prospective cohort of PLWH. All patients with CD4 cell count <200 cells/mm3 who had received additional dose of messenger RNA (mRNA) COVID-19 vaccine, after a standard immunization scheme were included. Control group: patients age- and sex-matched, with CD4 ≥ 200 cells/mm3 , in the ratio of 2:1. Antibody response to a booster dose (anti-S levels 33.8 ≥ BAU/mL) and neutralizing activity against SARS-CoV-2 B.1, B.1.617.2, and Omicron BA.1, BA.2, and BA.5 strains were assessed after the booster shot. Fifty-four PLWH were included, 18 with CD4 counts < 200 cells/mm3 . Fifty-one (94%) showed response to a booster dose. Response was less frequent in PLWH with CD4 < 200 cells/mm3 than in those with CD4 counts ≥ 200 cells/mm3 (15 [83%] vs. 36 [100%], p = 0.033). In the multivariate analysis, CD4 counts ≥ 200 cells/mm3 [incidence rate ratio (IRR) = 18.1 (95% confidence interval [CI]: 16.8-19.5), p < 0.001] was associated with a higher probability of showing antibody response. Neutralization activity against SARS-CoV-2 B.1, B.1.617, BA.1, and BA.2 strains was significantly inferior among individuals with CD4 counts < 200 cells/mm3 . In conclusion, among PLWH with CD4 counts < 200 cells/mm3 , the immune response elicited by mRNA additional vaccine dose is reduced.

Poor increase on HAV vaccination coverage among people living with HIV after an immunization-based intervention.

OBJECTIVES: To assess HAV serologic and vaccination status among people who live with HIV (PLWH), and to evaluate the impact of a vaccination-based strategy on HAV-negative patients in Seville, Spain. METHODS: Study with two time-overlapping phases: (i) cross-sectional study of HAV immunity prevalence among PLWH followed at a Spanish hospital between August 2019 and March 2020. (ii) Patients seronegative for HAV, reliably unvaccinated were included in a before-and-after quasi-experimental study, with an intervention focused on HAV vaccination according to national recommendations in force. RESULTS: Six hundred and fifty-six patients were included, of which 111 [17%, 95% confidence interval (95% CI) 14-20%] were seronegative for HAV. Of these, 48 [43% (95% CI, 34-53%)] individuals were MSM. The absence of HAV immunity was attributed in 69 [62% (95% CI, 52-71%)] patients to non-referral to vaccination, followed by lack of achievement of a correct vaccination scheme [n=26; 23% (95% CI, 16-32%)]. After the program implementation, 96 [15% (95% CI, 12-18%)] individuals were seronegative (17% vs. 15%, p=0.256), of whom 42 [41% (95% CI, 32-51%)] were MSM. The absence of immunity after the intervention was mainly attributed to: adherence failure in 23 [24.0% (95% CI, 15.8-33.7%)] patients, on-course immunization scheme in 34 [33% (95% CI, 24-43%)] individuals and pending appointment at the vaccine delivery unit in 20 [20.8% (95% CI, 13.2-30.3%)] patients. CONCLUSIONS: A sizeable proportion of PLWH remains susceptible for HAV infection in future outbreaks. A program based on referral to the vaccine delivery unit yields poor results, largely due to program adherence failures. New strategies are needed to increase HAV vaccination coverage.

Development and Characterisation of Joints with Novel Densified and Wood/Cork Composite Substrates.

The automotive industry, driven by the desire to decrease the environmental impact of vehicles, is permanently seeking to develop lightweight structural components, which lead to lower gas emissions and energy consumption, reducing their carbon footprint. In parallel, adopting innovative, constructive solutions, which dispense non-recyclable and energy-intensive materials, can increase the footprint reduction. Thus, an increase in the use of renewable materials for structural applications, including wood and its by-products, has been observed over the last few decades. Furthermore, composite materials are often joined by using petroleum-based synthetic adhesives, which should be progressively replaced by eco-friendly bio-adhesives. In this study, novel densified wood and wood/cork composites, joined with a bio-adhesive, are proposed and characterised. The densification of the wood aims to enhance the mechanical properties of the natural material, with the purpose of improving the energy absorption of the wood/bio-adhesive joint. To mitigate delamination and the brittle behaviour of wood/cork agglomerates were introduced between the wood substrate and the bio-adhesive. Different configurations of single lap joints (SLJ) were manufactured to study the effect of the overlap length and loading rate on the performance of the joints, both in terms of failure load and energy absorption. Afterward, the joints were numerically simulated. The densification process was successful, although it represents an additional challenge in terms of surface flatness, because the bio-adhesive requires zero bondline thickness. The increase of the overlap had a positive impact on the energy absorption of the joint, and the addition of cork resulted in a more consistent failure mode and higher strain to failure. The numerical models developed had a good correlation with the experimental results.

High efficacy of glecaprevir/pibrentasvir for HCV-infected individuals with active drug use.

OBJECTIVES: Real world data on glecaprevir/pibrentasvir (G/P) among active drug users are scarce. We evaluated the sustained virological response (SVR) rates of G/P among individuals with and without active drug use in routine clinical practice. METHODS: Two ongoing prospective multicenter cohorts of individuals starting G/P were analyzed. Overall SVR intention-to-treat (ITT), discontinuations due to adverse effects and dropouts were evaluated. Results in patients with active, past and without active drug use were compared. RESULTS: Overall, 644 individuals started G/P and have reached the date of SVR evaluation. Of them, 613 (95.2%) individuals achieved SVR. There were two (0.3%) relapses, one (0.2%) discontinuation due to side effects and 35 (5.4%) dropouts. SVR rates for patients with active drug use, past drug use and those who never used drugs were 85.4%(n/N = 70/82), 96.1%(n/N = 320/333) and 97.4%(n/N = 223/229) respectively (p < 0.001). After adjustment by sex, age, HCV genotype and opioid agonist therapy, active drug use was the only factor independently associated with SVR (ITT) [adjusted OR (95%confidence interval): 0.29(0.09-0.99),p = 0.048]. CONCLUSIONS: Active drug use was independently associated with lower SVR rates to G/P, mainly due to voluntary dropout. G/P could be particularly beneficial in this scenario but specific strategies designed to increase the retention in care are needed.

Severe immunosuppression is related to poorer immunogenicity to SARS-CoV-2 vaccines among people living with HIV.

OBJECTIVES: The aim of this study was to assess the immunogenicity of SARS-CoV-2 available vaccines among people living with HIV (PLWH) after a complete vaccination scheme, and determine predictors of seroconversion. METHODS: This multicentre prospective cohort study included 420 PLWH who had received a standard immunization, either with mRNA or adenoviral-vectored COVID-19 vaccines. Antibody response was evaluated within 1 to 2 months after the last dose of the vaccine with a quantitative determination of antitrimeric spike protein-specific IgG antibodies and IgG neutralizing antibodies. RESULTS: Overall, 384 of 420 PLWH (91%) showed antibody response to vaccination. Seroconversion was observed in 308 of 326 individuals with cluster of differentiation 4 (CD4) counts ≥350 cells/mm3 (95%), 55 of 61 PLWH with 200 to 349 cells/mm3 (90%), and 21 of 33 PLWH with CD4 counts <200 cells/mm3 (64%; p < 0.001). The median log10 IgG neutralization levels were 2.4 IU/mL (Q1-Q3, 1.0-3.1) among PLWH with CD4 counts <200 cells/mm3, 3.1 IU/mL (Q1-Q3, 2.8-3.4) for the 200 to 349 cells/mm3 group, and 3.1 IU/mL (Q1-Q3, 2.7-3.4) for PLWH with CD4 counts ≥350 cells/mm3 (p = 0.016). In the multivariate analysis, CD4 counts ≥350 cells/mm3 (OR: 7.10; 95% CI, 1.91-26.46; p = 0.004) and receiving mRNA-vectored COVID-19 vaccines (OR: 8.19; 95% CI, 3.24-20.70; p ≤ 0.001) were independently associated with a higher probability of response to vaccination. DISCUSSION: HIV-related immunosuppression impairs the antibody response to SARS-CoV-2 vaccines. Specific vaccination schemes should be urgently tailored in this setting, particularly in patients with CD4 cell counts <200 cells/µL. Adenoviral-vectored vaccines should be avoided in PLWH whenever possible.

Incidence of and factors associated with SARS-CoV-2 infection among people living with HIV in Southern Spain after one year of pandemic.

Whether people living with HIV (PLWH) are at greater risk of acquiring SARS-CoV-2 infection is currently unknown. Prospective serologic studies may allow seroincidence analyses, where all infections are accurately identified. Because of this, we evaluated the incidence of associated factors with and the clinical outcome of SARS-CoV-2 infection in PLWH in Southern Spain. This prospective cohort study included PLWH from a Tertiary University Hospital in Southern Spain. Patients were enrolled in the study if (1) they had attended as outpatients our Unit from 1 August 2019 to 8 February 2020 and (2) had two subsequent evaluations from 9 February 2020 to 4 March 2021. SARS-CoV-2 infections were diagnosed by PCR, antigen detection or serology. Seven hundred and nine PLWH were included in the study. Of them, 55 [7.8%, 95% confidence interval (95% CI) 5.9%-9.9%] patients developed SARS-CoV-2 infection. Between 18 May and 29 November 2020, the rate of seroconversion was 5.3% (95% CI: 3.1%-9.0%) for the general population in the area of Seville and 2.3% (95% CI: 1.3%-2.6%) for PLWH in this study (p = .001). After multivariable analysis, adjusted by age, sex, and risk factors for HIV infection, active tobacco use and CDC stage, active tobacco smoking was the only factor independently associated with lower risk of SARS-Cov-2 infection [Incidence rate ratio: 0.29 (95% CI 0.16-0.55) p < .001]. In conclusion, the incidence of SARS-CoV-2 infection among PLWH in Southern Spain during the ongoing pandemic was lower than that reported for the general population in the same area.

Genomic Characterization of Host Factors Related to SARS-CoV-2 Infection in People with Dementia and Control Populations: The GR@ACE/DEGESCO Study.

Emerging studies have suggested several chromosomal regions as potential host genetic factors involved in the susceptibility to SARS-CoV-2 infection and disease outcome. We nested a COVID-19 genome-wide association study using the GR@ACE/DEGESCO study, searching for susceptibility factors associated with COVID-19 disease. To this end, we compared 221 COVID-19 confirmed cases with 17,035 individuals in whom the COVID-19 disease status was unknown. Then, we performed a meta-analysis with the publicly available data from the COVID-19 Host Genetics Initiative. Because the APOE locus has been suggested as a potential modifier of COVID-19 disease, we added sensitivity analyses stratifying by dementia status or by disease severity. We confirmed the existence of the 3p21.31 region (LZTFL1, SLC6A20) implicated in the susceptibility to SARS-CoV-2 infection and TYK2 gene might be involved in COVID-19 severity. Nevertheless, no statistically significant association was observed in the COVID-19 fatal outcome or in the stratified analyses (dementia-only and non-dementia strata) for the APOE locus not supporting its involvement in SARS-CoV-2 pathobiology or COVID-19 prognosis.

Increased risk of severe clinical course of COVID-19 in carriers of HLA-C*04:01.

BACKGROUND: Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, there has been increasing urgency to identify pathophysiological characteristics leading to severe clinical course in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Human leukocyte antigen alleles (HLA) have been suggested as potential genetic host factors that affect individual immune response to SARS-CoV-2. We sought to evaluate this hypothesis by conducting a multicenter study using HLA sequencing. METHODS: We analyzed the association between COVID-19 severity and HLAs in 435 individuals from Germany (n = 135), Spain (n = 133), Switzerland (n = 20) and the United States (n = 147), who had been enrolled from March 2020 to August 2020. This study included patients older than 18 years, diagnosed with COVID-19 and representing the full spectrum of the disease. Finally, we tested our results by meta-analysing data from prior genome-wide association studies (GWAS). FINDINGS: We describe a potential association of HLA-C*04:01 with severe clinical course of COVID-19. Carriers of HLA-C*04:01 had twice the risk of intubation when infected with SARS-CoV-2 (risk ratio 1.5 [95% CI 1.1-2.1], odds ratio 3.5 [95% CI 1.9-6.6], adjusted p-value = 0.0074). These findings are based on data from four countries and corroborated by independent results from GWAS. Our findings are biologically plausible, as HLA-C*04:01 has fewer predicted bindings sites for relevant SARS-CoV-2 peptides compared to other HLA alleles. INTERPRETATION: HLA-C*04:01 carrier state is associated with severe clinical course in SARS-CoV-2. Our findings suggest that HLA class I alleles have a relevant role in immune defense against SARS-CoV-2. FUNDING: Funded by Roche Sequencing Solutions, Inc.

A Genome-Wide Association Study on Liver Stiffness Changes during Hepatitis C Virus Infection Cure.

Liver stiffness (LS) at sustained virological response (SVR) after direct-acting antivirals (DAA)-based therapy is a predictor of liver events in hepatitis C virus (HCV)-infected patients. The study aim was to identify genetic factors associated with LS changes from the moment of starting anti-HCV therapy to SVR. This prospective study included HCV-infected patients from the GEHEP-011 cohort who achieved SVR with DAA-based therapy, with LS pre-treatment ≥ 9.5 kPa and LS measurement available at SVR. Plink and Magma software were used to carry out genome-wide single-nucleotide polymorphism (SNP)-based and gene-based association analyses, respectively. The ShinyGO application was used for exploring enrichment in Gene Ontology (GO) categories for biological processes. Overall, 242 patients were included. Median (quartile 1, quartile 3) LS values at pre-treatment and at SVR were 16.8 (12, 28) kPa and 12.0 (8.5, 19.3) kPa, respectively. Thirty-five SNPs and three genes reached suggestive association with LS changes from the moment of starting anti-HCV therapy to SVR. GO categories related to DNA packaging complex, DNA conformation change, chromosome organization and chromatin organization were significantly enriched. Our study reports possible genetic factors associated with LS changes during HCV-infection cure. In addition, our results suggest that processes related to DNA conformation are also involved in these changes.

The Other Side of SARS-CoV-2 Infection: Neurological Sequelae in Patients.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread around the globe causing coronavirus disease 2019 (COVID-19). Because it affects the respiratory system, common symptoms are cough and breathing difficulties with fever and fatigue. Also, some cases progress to acute respiratory distress syndrome (ARDS). The acute phase of COVID-19 has been also related to nervous system symptoms, including loss of taste and smell as well as encephalitis and cerebrovascular disorders. However, it remains unclear if neurological complications are due to the direct viral infection of the nervous system, or they appear as a consequence of the immune reaction against the virus in patients who presented pre-existing deficits or had a certain detrimental immune response. Importantly, the medium and long-term consequences of the infection by SARS-CoV-2 in the nervous system remain at present unknown. This review article aims to give an overview of the current neurological symptoms associated with COVID-19, as well as attempting to provide an insight beyond the acute affectation.

Similar incidence of coronavirus disease 2019 (COVID-19) in patients with rheumatic diseases with and without hydroxychloroquine therapy.

BACKGROUND: Hydroxychloroquine is not efficacious as post-exposure prophylaxis against coronavirus disease 2019 (COVID-19). It is not known whether as pre-exposure prophylaxis it may prevent COVID-19. OBJECTIVE: To compare the incidence of COVID-19 in Spanish patients with autoimmune rheumatic diseases treated with and without hydroxychloroquine. PATIENTS AND METHODS: Retrospective electronic record review, from February 27th to June 21st, 2020, of patients with autoimmune inflammatory diseases followed at two academic tertiary care hospitals in Seville, Spain. The cumulative incidence of confirmed COVID-19, by PCR or serology, was compared between patients with and without hydroxychloroquine as part of their treatment of autoimmune inflammatory diseases. RESULTS: Among 722 included patients, 290 (40%) were receiving hydroxychloroquine. During the seventeen-week study period, 10 (3.4% [95% CI: 1.7%-6.7%] cases of COVID-19 were registered among patients with hydroxychloroquine and 13 (3.0% [1.6%-5.1%]) (p = 0.565) in those without hydroxychloroquine. COVID-19 was diagnosed by PCR in four (1.4%, 95% CI 0.38%-3.5%) subject with hydroxychloroquine and six (1.4%, 95% CI 0.5%-3.0%) without hydroxychloroquine (p = 0.697). Three patients on hydroxychloroquine and four patients without hydroxychloroquine were admitted to the hospital, none of them required to be transferred to the intensive care unit and no patient died during the episode. CONCLUSIONS: The incidence and severity of COVID-19 among patients with autoimmune rheumatic diseases with and without hydroxychloroquine was not significantly different.

Impact of recent drug use on the efficacy of elbasvir/grazoprevir for HCV-infected people on opioid agonist therapy.

Elbasvir/grazoprevir (EBR/GZR) use in drug users on opiate agonist therapy (OAT) is supported by the C-EDGE Co-STAR trial. SVR rates in this study were within those found in the rest of patients included by the EBR/GZR development programme. In clinical practice, however, efficacy could theoretically be lower. Thus, we aimed at evaluating the SVR rates of EBR/GZR among people who injected drugs (PWID) with and without OAT in clinical practice. Patients starting EBR/GZR included in the HEPAVIR-DAA (NCT02057003), recruiting HIV/HCV-coinfected patients or the GEHEP-MONO (NCT02333292), including HCV-monoinfected individuals, prospective cohorts were analysed. Overall SVR12 (ITT), discontinuations due to adverse effects and drop-outs were evaluated. The same analysis was carried out for PWID with and without OAT. 336 patients had started EBR/GZR and reached the SVR12 evaluation date. 318 [95%, 95% confidence interval (95% CI): 92%-98%] patients achieved SVR12. SVR12 was 97% (95% CI: 93%-99%, n/N = 141/145) among people who never used injecting drugs, 94% (95% CI: 88%-97%, n/N = 117/125) among PWIDs without OAT and 91% (95% CI: 81%-97%, n/N = 60/66) among PWIDs with OAT (p = 0.134). Five (1.5%) patients showed relapses, and two (0.6%) individuals showed viral breakthrough. The SVR12 rate for recent drug users was 69% (n/N = 18/26) compared with 97% (n/N = 276/284) for individuals without recent drug use (in the prior year) (p < 0.001). Among recent drug users, three (12%) showed relapses, and five (19%) were lost-to-follow-up. The SVR rates achieved with EBR/GZR were high in real-world conditions of use. However, PWID with recent drug use reach suboptimal response rates with EBR/GZR.

High rate of major drug-drug interactions of lopinavir-ritonavir for COVID-19 treatment.

The impact of drug-drug interactions (DDI) between ritonavir-boosted lopinavir (LPV-r) to treat patients with coronavirus disease 2019 (COVID-19) and commonly used drugs in clinical practice is not well-known. Thus, we evaluated the rate and severity of DDI between LPV-r for COVID-19 treatment and concomitant medications. This was a cross-sectional study including all individuals diagnosed of SARS-CoV-2 infection treated with LPV-r and attended at a single center in Southern Spain (March 1st to April 30th, 2020). The frequency [95% confidence interval (95% CI)] of potential and major DDI were calculated. Overall, 469 patients were diagnosed of COVID-19, 125 (27%) of them were prescribed LPV-r. LPV-r had potential DDI with concomitant medications in 97 (78%, 95% CI 69-85%) patients, and in 33 (26%, 95% CI 19-35%) individuals showed major DDI. Twelve (36%) patients with major DDI and 14 (15%) individuals without major DDI died (p = 0.010). After adjustment, only the Charlson index was independently associated with death [adjusted OR (95% CI) for Charlson index ≥ 5: 85 (10-731), p < 0.001]. LPV-r was discontinued due to side effects in 31 (25%) patients. Management by the Infectious Diseases Unit was associated with a lower likelihood of major DDI [adjusted odds ratio (95% CI): 0.14 (0.04-0.53), p = 0.003). In conclusion, a high frequency of DDI between LPV-r for treating COVID-19 and concomitant medications was found, including major DDI. Patients with major DDI showed worse outcomes, but this association was explained by the older age and comorbidities. Patients managed by the Infectious Diseases Unit had lower risk of major DDI.

Association of complement C3d receptor 2 genotypes with the acquisition of HIV infection in a trial of recombinant glycoprotein 120 vaccine.

OBJECTIVES: Complement C3d receptor 2 (CR2) is the main receptor for complement protein C3d and plays an important role in adaptive immune responses. CR2 genetic variants are associated with susceptibility to systemic lupus erythematosus as well as to HIV-1 infection. In addition, CR2 function can be subverted by HIV-1 for an efficient entry into target cells; in a process known as antibody-dependent enhancement of viral infection. We sought to determine the association between CR2 gene variants with HIV-1 acquisition after vaccination with recombinant gp120 protein (Vax004 clinical trial). DESIGN AND METHODS: This is a retrospective cross-sectional study, comprising male volunteers of European ancestry including infected (n = 273) and uninfected (n = 402) vaccinees and placebo, who were genotyped for three single nucleotide polymorphisms (SNPs) in the CR2 gene region. RESULTS: An interaction was observed between the baseline sexual behavior and the SNP rs3813946 for higher risk of infection in vacinees (interaction term P = 0.02). This SNP was associated with increased susceptibility to HIV-1 infection after vaccination in volunteers with low behavioral risk odds ratio (95% confidence interval): 5.5 (1.4-21.7) P = 0.006 but not vaccinees with high behavioral risk or volunteers given placebo (P = 0.7). Moreover, CR2 genotype was strongly associated with the rate of HIV-1 acquisition after vaccination in low-risk volunteers [hazard odds ratio (95% confidence interval): 3.3 (1.6-7.0), P = 0.001]. CONCLUSION: The current study suggests that CR2 may play a role in HIV-1 acquisition after vaccination with rgp120 proteins.

A genome-wide association study on low susceptibility to hepatitis C virus infection (GEHEP012 study).

BACKGROUND: A low proportion of individuals repeatedly exposed to the hepatitis C virus (HCV) remain uninfected. This condition could have a genetic basis but it is not known whether or not it is mainly driven by a high-penetrance common allele. OBJECTIVE: To explore whether low susceptibility to HCV infection is mainly driven by a high-penetrance common allele. METHODS: In this genome-wide association study (GWAS), a total of 804 HCV-seropositive individuals and 27 high-risk HCV-seronegative (HRSN) subjects were included. Plink and Magma software were used to carry out single nucleotide polymorphism (SNP)-based and gene-based association analyses respectively. RESULTS: No SNP nor any gene was associated with low susceptibility to HCV infection after multiple testing correction. However, SNPs previously associated with this trait and allocated within the LDLR gene, rs5925 and rs688, were also associated with this condition in our study under a dominant model (24 out of 27 [88.9%] rs5925-C carriers in the HRSN group vs 560 of 804 [69.6%] rs5925-C carriers in the HCV-seropositive group, P = 0.031, odds ratio [OR] = 3.48; 95% confidence interval [CI] = 1.04-11.58; and 24 out of 27 [88.9%] rs688-T carriers in the HRSN group vs 556 of 804 [69.1%] rs688-T carriers in the HCV-seropositive group, P = 0.028, OR = 3.57, 95% CI = 1.65-11.96). CONCLUSIONS: Low susceptibility to HCV infection does not seem to be mainly driven by a high-penetrant common allele. By contrast, it seems a multifactorial trait where genes such as LDLR could be involved.

Galectin-3, a novel endogenous TREM2 ligand, detrimentally regulates inflammatory response in Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disease in which the formation of extracellular aggregates of amyloid beta (Aß) peptide, fibrillary tangles of intraneuronal tau and microglial activation are major pathological hallmarks. One of the key molecules involved in microglial activation is galectin-3 (gal3), and we demonstrate here for the first time a key role of gal3 in AD pathology. Gal3 was highly upregulated in the brains of AD patients and 5xFAD (familial Alzheimer's disease) mice and found specifically expressed in microglia associated with Aß plaques. Single-nucleotide polymorphisms in the LGALS3 gene, which encodes gal3, were associated with an increased risk of AD. Gal3 deletion in 5xFAD mice attenuated microglia-associated immune responses, particularly those associated with TLR and TREM2/DAP12 signaling. In vitro data revealed that gal3 was required to fully activate microglia in response to fibrillar Aß. Gal3 deletion decreased the Aß burden in 5xFAD mice and improved cognitive behavior. Interestingly, a single intrahippocampal injection of gal3 along with Aß monomers in WT mice was sufficient to induce the formation of long-lasting (2 months) insoluble Aß aggregates, which were absent when gal3 was lacking. High-resolution microscopy (stochastic optical reconstruction microscopy) demonstrated close colocalization of gal3 and TREM2 in microglial processes, and a direct interaction was shown by a fluorescence anisotropy assay involving the gal3 carbohydrate recognition domain. Furthermore, gal3 was shown to stimulate TREM2-DAP12 signaling in a reporter cell line. Overall, our data support the view that gal3 inhibition may be a potential pharmacological approach to counteract AD.