Impact of HLA allele-KIR partners on sexually transmitted HIV-1 infection.

HLA-I/KIR genotypes influence HIV-1 disease progression and viral load, but their role in primary infection is uncertain. Inconsistent results from previous studies suggest that the inoculum size and transmission route-parenteral vs. sexual-may influence this association. We conducted a GWAS in a population of people living with HIV-1 and HIV-1-exposed seronegative individuals exposed to the virus through the sexual route. Our data do not support any role of the HLA/KIR system in susceptibility to sexually transmitted HIV-1 infection. The genetics basis of HIV-1 viral load and disease progression are distinct from the genetics of HIV resistance, a paradox worth exploring.

Phylogeography of Hyalomma (Euhyalomma) lusitanicum (Acarina, Parasitiformes, Ixodidae) in Andalusia based on mitochondrial cytochrome oxidase I gene.

The genetic population structure relationships of Hyalomma (Euhyalomma) lusitanicum in Andalusia (the south of the Iberian Peninsula) were examined using mtDNA sequence data from 887 bp of cytochrome oxidase subunit I (COI) gene. The sequence for the COI region was determined for 84 individuals collected in several localities of Andalusia, and 10 for other localities (i.e., five from Toledo, central Iberian Peninsula, four from Sicily (Italy) and one from Canary Island). Seventeen haplotypes were detected, including 27 polymorphic sites. The number of amino acid substitutions per site from mean diversity calculations for the entire population was 0.017. AMOVA analysis revealed a low gene flow that characterises the genetic population structure of this species in South Iberian Peninsula, with a haplotype diversity (h) value of 0.815. No geographically induced differentiation was observed, and separate evolutionary units were not detected. Our results indicate low genetic diversity across the geographical range of H. lusitanicum tick in Andalusia. Our data do not show any genetic discontinuity between the tick populations studied, including specimens from Canary Island and Sicily (Italy).

Toll-Like Receptor 2 Promoter -196 to -174 Deletion Affects CD4 Levels Along Human Immunodeficiency Virus Infection Progression.

Toll-like receptor 2 (TLR2) plays a key role in innate immune response recognizing molecular patterns expressed by pathogens. rs111200466 is a TLR2 promoter insertion/deletion polymorphism with contradictory data about its role in human immunodeficiency virus type 1 (HIV-1) infection. We analyzed rs111200466 in HIV-1 disease progression and showed a correlation with a faster progression to the CD4+ < 200 cells/µL outcome for deletion allele carriers (Cox regression analysis: hazard ratio, 2.4 [95% confidence interval, 1.4-4]; P = .001). When naive patients with CD4+ < 200 cells/µL started antiretroviral treatment, rs111200466-deletion carriers showed a trend toward a slower, recovery rate (time required to reach CD4+ > 350 cells/µL; Cox P = .36). Our data suggest rs111200466 as a prognosis factor for HIV-1 disease progression.

The role of a functional variant of TYK2 in vasculitides and infections.

OBJECTIVES: The TYK2 gene encodes a tyrosin kinase which is involved in multiple immune functions. A functional variant of this gene has been identified to play a protective role in multiple autoimmune diseases. The goal of this study was to evaluate the involvement of this variant of TYK2 in vasculitides [giant cell arteritis (GCA), ANCA-associated vasculitis (AAV) and IgA vasculitis (IgAV)] and viral infections [hepatitis C virus (HCV) and human immunodeficiency virus type I (HIV-1)]. METHODS: The study sample was composed of 13,745 European individuals. The genotyping was performed by Immunochip and TaqMan 5' allele discrimination assays and the allele frequencies were compared using PLINK. RESULTS: Although the results obtained did not reach the genome-wide level of significance, p-values at nominal significance were observed, suggesting that the TYK2 variant provides protection against two vasculitides: GCA (p=5.94E-3; OR (95%CI) = 0.56 (0.37-0.85) and AAV (p=6.79E-3; OR (95%CI) = 0.65 (0.47-0.89). However, this variant was not found to be associated with IgAV. No evidence was gained that the TYK2 variant confers susceptibility to HCV and HIV-1 infection. CONCLUSIONS: This is the first study to propose the association between the TYK2 and both GCA and AAV. Our findings also suggest that TYK2 does not play a relevant role in IgAV or in susceptibility to HCV and HVI-1.

Complement C4 Gene Copy Number Variation Genotyping by High Resolution Melting PCR.

BACKGROUND: Complement C4 gene copy number variation plays an important role as a determinant of genetic susceptibility to common diseases, such as systemic lupus erythematosus, schizophrenia, rheumatoid arthritis, and infectious diseases. This study aimed to develop an assay for the quantification of copy number variations in the C4 locus. METHODS: the assay was based on a gene ratio analysis copy enumeration (GRACE) PCR combined with high resolution melting (HRM) PCR. The test was optimized using samples of a known genotype and validated with 72 DNA samples from healthy blood donors. RESULTS: to validate the assay, standard curves were generated by plotting the C4/RP1 ratio values against copy number variation (CNV) for each gene, using genomic DNA with known C4 CNV. The range of copy numbers in control individuals was comparable to distributions observed in previous studies of European descent. CONCLUSIONS: the method herein described significantly simplifies C4 CNV diagnosis to validate the assay.

A Knockout IFNL4 Variant Is Associated With Protection From Sexually Transmitted HIV-1 Infection.

An interferon λ4 gene (IFNL4) knockout allele (rs368234815; TT) is associated with spontaneous and IFN-α-dependent cure of hepatitis C virus infection. The role of this polymorphism in the susceptibility to human immunodeficiency virus type 1 (HIV-1) infection is controversial. This study aimed to assess the association of this knockout IFNL4 variant and sexually transmitted HIV-1 infection. A total of 228 HIV-1-positive individuals and 136 HIV-exposed seronegative individuals were investigated for their association with IFNL4 rs368234815 genotypes. The IFNL4 ΔG functional allele is associated with increased susceptibility to HIV-1 infection through the sexual route (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.2-3.6; P = .004). A meta-analysis including a population of injection drug users suggests a codominant mode of inheritance of this risk factor (OR, 2.0; 95% CI, 1.3-3.2; P = .001).

Evolutionary analysis identifies an MX2 haplotype associated with natural resistance to HIV-1 infection.

The protein product of the myxovirus resistance 2 (MX2) gene restricts HIV-1 and simian retroviruses. We demonstrate that MX2 evolved adaptively in mammals with distinct sites representing selection targets in distinct branches; selection mainly involved residues in loop 4, previously shown to carry antiviral determinants. Modeling data indicated that positively selected sites form a continuous surface on loop 4, which folds into two antiparallel α-helices protruding from the stalk domain. A population genetics-phylogenetics approach indicated that the coding region of MX2 mainly evolved under negative selection in the human lineage. Nonetheless, population genetic analyses demonstrated that natural selection operated on MX2 during the recent history of human populations: distinct selective events drove the frequency increase of two haplotypes in the populations of Asian and European ancestry. The Asian haplotype carries a susceptibility allele for melanoma; the European haplotype is tagged by rs2074560, an intronic variant. Analyses performed on three independent European cohorts of HIV-1-exposed seronegative individuals with different geographic origin and distinct exposure route showed that the ancestral (G) allele of rs2074560 protects from HIV-1 infection with a recessive effect (combined P = 1.55 × 10(-4)). The same allele is associated with lower in vitro HIV-1 replication and increases MX2 expression levels in response to IFN-α. Data herein exploit evolutionary information to identify a novel host determinant of HIV-1 infection susceptibility.

A polymorphism linked to RRAS, SCAF1, IRF3 and BCL2L12 genes is associated with cirrhosis in hepatitis C virus carriers.

BACKGROUND & AIMS: Host genetic factors could play a primary role in determining risk for cirrhosis development in HCV-infected patients. The aims of this study were to discover new genetic variants associated with this trait and to replicate some associations formerly reported. METHODS: Three hundred and thirty-seven HCV carriers with available data about liver fibrosis status, who initiated treatment with pegylated interferon plus ribavirin, were included. Of them, 77 (22.85%) were cirrhotic. One hundred and forty-four SNPs from 40 genes related to cholesterol metabolism/transport, sustained viral response to HCV therapy, liver fibrosis, or immune response, were genotyped in all samples. Plink software was used to perform univariate association analyses. The results obtained were adjusted by other parameters related to cirrhosis using multivariate logistic regression models. RESULTS: Only the SNP rs12104272, linked to RRAS, SCAF1, IRF3 and BCL2L12 genes, was associated with cirrhosis. It was observed a higher proportion of rs12104272 A allele carriers in the non-cirrhotic group (60.63%) than in the cirrhotic group (38.15%) (adjusted OR = 0.36, 95% CI = 0.180-0.746, P = 0.006). This effect was stronger in the background of rs12979860 CC genotype of IL28B (adjusted OR = 0.069, 95% CI = 0.014-0.349, P = 0.001). CONCLUSION: The rs12104272 SNP could have clinical value to select those individuals at lower risk for cirrhosis development.

A common polymorphism in TLR3 confers natural resistance to HIV-1 infection.

TLR3 recognizes dsRNA and activates antiviral immune responses through the production of inflammatory cytokines and type I IFNs. Genetic association studies have provided evidence concerning the role of a polymorphism in TLR3 (rs3775291, Leu412Phe) in viral infection susceptibility. We genotyped rs3775291 in a population of Spanish HIV-1-exposed seronegative (HESN) individuals who remain HIV seronegative despite repeated exposure through i.v. injection drug use (IDU-HESN individuals) as witnessed by their hepatitis C virus seropositivity. The frequency of individuals carrying at least one 412Phe allele was significantly higher in IDU-HESN individuals compared with that of a matched control sample (odds ratio for a dominant model = 1.87; 95% confidence interval, 1.06-3.34; p = 0.023). To replicate this finding, we analyzed a cohort of Italian, sexually HESN individuals. Similar results were obtained: the frequency of individuals carrying at least one 412Phe allele was significantly higher compared with that of a matched control sample (odds ratio, 1.79; 95% confidence interval, 1.05-3.08; p = 0.029). In vitro infection assays showed that in PBMCs carrying the 412Phe allele, HIV-1(Ba-L) replication was significantly reduced (p = 0.025) compared with that of Leu/Leu homozygous samples and was associated with a higher expression of factors suggestive of a state of immune activation (IL-6, CCL3, CD69). Similarly, stimulation of PBMCs with a TLR3 agonist indicated that the presence of the 412Phe allele results in a significantly increased expression of CD69 and higher production of proinflammatory cytokines including IL-6 and CCL3. The data of this study indicate that a common TLR3 allele confers immunologically mediated protection from HIV-1 and suggest the potential use of TLR3 triggering in HIV-1 immunotherapy.

Association of BST-2 gene variants with HIV disease progression underscores the role of BST-2 in HIV type 1 infection.

We tested bone marrow stromal cell antigen 2 (BST-2) gene variants rs3217318, a 19-base-pair insertion/deletion polymorphism in the promoter region, and rs10415893, a tag single-nucleotide polymorphism in the 3' untranslated region, for their association with human immunodeficiency virus type 1 (HIV-1) infection and disease progression. The study included 356 subjects exposed to HIV-1 (185 with and 171 without infection) and 188 controls. The first decrease in the CD4(+) T-cell count to <200 cells/µL was used as the primary outcome, whereas the primary outcome plus initiation of any antiretroviral treatment was used as a secondary composite outcome. Association with progression was found for both rs3217318 and rs10415893, following an overdominant model. Diplotype analysis revealed faster progression to both outcomes for subjects carrying the Δ19_G/i19_A diplotype. Luciferase assay showed that a promoter sequence containing the i19 allele had the lowest expression levels, suggesting that i19 allele carriers could have less BST-2 expression, reducing their capability to retain viral particles. These results point to the relevance of BST-2 as a host genetic factor modifying HIV-1 disease progression.

A model to predict the response to therapy against hepatitis C virus (HCV) including low-density lipoprotein receptor genotype in HIV/HCV-coinfected patients.

OBJECTIVES: Accurate prediction of sustained virological response (SVR) to pegylated interferon-α (Peg-IFN) plus ribavirin in HIV/hepatitis C virus (HCV)-coinfected patients could improve the management of these patients. We aimed to develop a model to predict SVR to Peg-IFN/ribavirin in HIV/HCV-coinfected individuals combining HCV genotype and baseline HCV RNA load with interleukin 28B and low-density lipoprotein receptor genetic variations. METHODS: Three hundred and twelve treatment-naive HIV/HCV-coinfected patients receiving Peg-IFN/ribavirin were analysed in an on-treatment approach. One hundred and eighty-one of them were included in the development group and 131 in the validation population. The predictive model was obtained from a logistic regression equation including the above-mentioned variables. The areas under the receiver operating characteristic (AUROC) curves (95% CI), sensitivity and specificity, as well as negative and positive predictive values, were calculated. RESULTS: SVR was achieved by 88 (48.6%) patients from the development group and 68 (51.9%) individuals from the validation group. The AUROC curve values (95% asymptotic CI) were 0.83 (0.77-0.89) for the development group and 0.84 (0.77-0.91) for the validation group. Using two cut-off values, maximum specificity and sensitivity were 89.7% and 96.6%, respectively, with a negative predictive value for SVR of 88.9% and a positive predictive value of 83.6%. Thirteen (7.2%) individuals were misclassified using these cut-off values. CONCLUSIONS: This model represents a reliable and easily applicable tool to individually evaluate the probability of achieving an SVR to Peg-IFN/ribavirin among HIV/HCV-coinfected patients.

Site-directed antibody immobilization using a protein A-gold binding domain fusion protein for enhanced SPR immunosensing.

We have implemented a novel strategy for the oriented immobilization of antibodies onto a gold surface based on the use of a fusion protein, the protein A-gold binding domain (PAG). PAG consists of a gold binding peptide (GBP) coupled to the immunoglobulin-binding domains of staphylococcal protein A. This fusion protein provides an easy and fast oriented immobilization of antibodies preserving its native structure, while leaving the antigen binding sites (Fab) freely exposed. Using this immobilization strategy, we have demonstrated the performance of the immunosensing of the human Growth Hormone by SPR. A limit of detection of 90 ng mL(-1) was obtained with an inter-chip variability lower than 7%. The comparison of this method with other strategies for the direct immobilization of antibodies over gold surfaces has showed the enhanced sensitivity provided by the PAG approach.

Prediction of response to pegylated interferon plus ribavirin in HIV/hepatitis C virus (HCV)-coinfected patients using HCV genotype, IL28B variations, and HCV-RNA load.

BACKGROUND & AIMS: This study aimed at developing a predictive algorithm based on interleukin 28B (IL28B) genotype, hepatitis C virus (HCV) genotype, and plasma HCV-RNA load, which could accurately allow us to define the probability of response to pegylated interferon (Peg-IFN) plus ribavirin (RBV) therapy in HIV/HCV-coinfected patients. METHODS: Five hundred and twenty-one treatment-naive HIV-infected patients, who initiated HCV therapy with Peg-IFN/RBV, were analysed in an on-treatment basis. Patients were categorized as unlikely responders, uncertain responders, and anticipated responders (<20%, 20-60%, and >60% probability to achieve SVR, respectively). RESULTS: HCV genotype, baseline HCV-RNA load, and IL28B genotype were confirmed as independent predictors of SVR in a logistic regression analysis. A stepwise algorithm based on these three variables was created based on 321 patients and evaluated in the remaining 200 patients. Unlikely responders included patients with genotype 1 or 4, HCV-RNA load ≥600,000IU/ml, and rs12979860 non-CC (rate of SVR: 17.3%). Anticipated responders were those with HCV genotype 2-3, patients harboring HCV genotype 4 and IL28B CC, as well as those who simultaneously bore HCV genotype 1, HCV-RNA load <600,000IU/ml, and IL28B CC (rate of SVR 74.1%, 77.8%, and 64.4%, respectively). The area under the receiver operating characteristic curve of the model was 0.77 (0.733-0.814). CONCLUSIONS: The combined use of IL28B genotype, HCV genotype, and HCV-RNA load enables to easily identify patients with a high and very low likelihood of SVR. HCV therapy could be deferred in the latter patients, until more effective options are available, at least if they do not show advanced liver fibrosis.

Association between the IL28B genotype and hepatitis C viral kinetics in the early days of treatment with pegylated interferon plus ribavirin in HIV/HCV co-infected patients with genotype 1 or 4.

OBJECTIVES: To evaluate the effect of the interleukin 28B (IL-28B) genotype on hepatitis C virus (HCV) viral kinetics in the first 4 weeks from start of treatment with pegylated interferon plus ribavirin (PEG-IFN/RBV) in HIV/HCV co-infected patients. METHODS: HIV/HCV co-infected patients naive to PEG-IFN/RBV treatment were enrolled in a prospective study. HCV RNA plasma viral loads were measured at baseline and at weeks 1, 2 and 4 after commencement of treatment. Patients were grouped by HCV genotype (genotype 1/4 versus 3) and by IL-28B genotype (CC versus non-CC). Differences in viral load reduction were evaluated by IL-28B genotype between baseline, week 1, week 2 and week 4. RESULTS: One hundred and nineteen HIV/HCV patients were included in the study. HCV patients with genotype 1/4 and bearing the IL-28 CC genotype showed the greatest reductions in HCV RNA plasma levels between baseline and weeks 1 (B-1), 2 (B-2) and 4 (B-4) than did those with non-CC genotypes (B-1: 1.06 ± 0.89 versus 0.48 ± 0.48 log IU/mL, P = 0.009; B-2: 1.36 ± 0.72 versus 0.77 ± 0.66 log IU/mL, P = 0.01; and B-4: 1.91 ± 0.64 versus 1.38 ± 0.96 log IU/mL, P = 0.03). However, differences between weeks 1 and 2 (W1-2) and between weeks 2 and 4 (W2-4) were not associated with the IL-28B genotype (W1-2: CC 0.48 ± 0.42 versus non-CC 0.38 ± 0.38 log IU/mL, P = 0.62; W2-4: CC 0.32 ± 0.23 versus non-CC 0.39 ± 0.31 log IU/mL, P = 0.67). No differences in decline of HCV RNA viral load were found in HCV genotype 3 patients. CONCLUSIONS: The IL-28B genotype impacts on viral kinetics during the first week of treatment with PEG-IFN/RBV in patients with HCV genotype 1/4.

Influence of interleukin-28B single-nucleotide polymorphisms on progression to liver cirrhosis in human immunodeficiency virus-hepatitis C virus-coinfected patients receiving antiretroviral therapy.

BACKGROUND: Single-nucleotide polymorphisms (SNPs) near the IL28B gene have recently been associated with spontaneous hepatitis C virus (HCV) clearance and response to interferon-based therapies in patients with chronic hepatitis C. Because human immunodeficiency virus (HIV) coinfection appears to accelerate HCV-related liver fibrosis progression, any influence of IL28B SNP on the risk of developing cirrhosis might be more easily recognized in the coinfected population. METHODS: All HIV-HCV-coinfected patients who underwent hepatic elastography before initiating a course of pegylated interferon plus ribavirin therapy at 2 Spanish clinics were retrospectively identified. Liver cirrhosis was defined as >14.5 kPa by transient elastography. The IL28B rs12979860 SNP was examined in a blinded fashion. RESULTS: A total of 304 HIV-HCV-coinfected individuals were analyzed (mean age, 43 years; 80% were male; and 85% were receiving antiretroviral therapy), of whom 18% had cirrhosis. IL28B genotype distribution was as follows: CC, 46%; CT, 43%; and TT, 11%. Cirrhosis was more frequent in CC than CT/TT carriers (24% vs 13%; P = .01). Logistic regression analysis revealed that older age (odds ratio [OR], 1.05; 95% confidence interval [CI], 0.99-1.12]; P = .08), past alcohol abuse (OR, 1.97; 95% CI, 0.95-4.06; P = .07), and CC IL28B genotype (OR, 2.32; 95% CI, 1.22-4.41; P = .01) were predictors of cirrhosis. Interestingly, mean (SD) alanine aminotransferase (ALT) levels were greater (90 ± 53 vs 71 ± 33 IU/L;, P = .01) in IL28B CC than CT/TT carriers during the prior 4.8 ± 3.8 years. CONCLUSIONS: The IL28B rs12979860 CC genotype is associated with a higher prevalence of cirrhosis in HIV-HCV-coinfected patients than CT/TT genotypes, suggesting that IL28B CC carriers may experience a more rapid progression of HCV-related liver fibrosis, perhaps as result of increased liver inflammation. Thus, access to HCV treatment is of utmost importance in IL28B CC carriers, in whom treatment response is better and in whom progression to cirrhosis might occur more rapidly.

Serologic study of Bartonella sp. infection among human population of Southern Spain.

INTRODUCTION: The purpose of this study was to determine the prevalence of IgG antibodies against Bartonella sp. in a randomly selected sample from the population of the patients of North Sanitary District of Jaén. METHODS: We used a commercially available immunofluorescent test (Focus-Technology IFA Bartonella quintana and B. henselae test). RESULTS: Six hundred five healthy individuals were divided by sex into three age groups. We detected that 13.55% and 11.07% subjects were IgG seropositive to B. henselae and B. quintana, respectively. CONCLUSIONS: Our data show that the prevalence of both Bartonella species in Andalusia (Southern Spain) is relatively high. No statistical difference in the seropositivity was observed among these groups. In both cases, the IgG antibody titers ranged from 1/128 to 1/512.

IFNL4 genotype influences the rate of HIV-1 seroconversion in men who have sex with men.

Individuals lacking interferon lambda 4 (IFNL4) protein due to a common null mutation (rs368234815) in the IFNL4 gene display higher resistance against several infections. The influence of IFNL4 on HIV-1 infection is still under discussion and conflicting results have been reported. This study intended to corroborate or refute the association of the null allele of IFNL4 and HIV-1 predisposition in a cohort of men who have sex with men (MSM). IFNL4 null genotype was assessed on 619 HIV-1-seronegative MSM who were followed for 36 months during a trial of a prophylactic vaccine against HIV-1. Of those, 257 individuals seroconverted during this period. A logistic regression model was constructed including demographic and IFNL4 genotype. In addition, a meta-analysis using data from the current study and other European populations was conducted. The null IFNL4 genotypes were correlated with lower HIV-1 seroconversion (Adjusted OR = 0.4 [95%CI: 0.2-0.8], P = 0.008) and longer time to seroconversion (889 vs. 938 days, P= 0.01). These results were validated by a meta-analysis incorporating data from other European populations and the result yielded a significant association of the IFNL4 null genotype under a dominant model with a lower probability of HIV-1 infection (OR=0.4 [95% CI: 0.3-0.6]; P= 1.3 x 10E-5).

No association of a risk variant for severe COVID-19 with HIV protection in three cohorts of highly exposed individuals.

An extended haplotype on chromosome 3 is the major genetic risk factor for severe COVID-19. The risk haplotype, which was inherited from Neanderthals, decreases the expression of several cytokine receptors, including CCR5. Recently, a study based on three general population cohorts indicated that the minor allele of one of the variants in the haplotype (rs17713054) protects against HIV infection. We thus expected this allele to be over-represented in highly exposed individuals who remain uninfected (exposed seronegative individuals, ESN). To perform a meta-analysis, we genotyped rs17713054 in three ESN cohorts of European ancestry exposed to HIV through different routes. No evidence of association was detected in the single cohorts. The meta-analysis also failed to detect any effect of the variant on protection from HIV-1. The same results were obtained in a Cox-regression analysis for the time to seroconversion. An in-vitro infection assay did not detect differences in viral replication as a function of rs17713054 genotype status. We conclude that the rs17713054 minor allele is not associated with the ESN phenotype and does not modulate HIV infection in vitro.

Distribution of Interferon Lambda 4 Single Nucleotide Polymorphism rs11322783 Genotypes in Patients with COVID-19.

Type III interferons (IFN-III), also known as IFN-Lambda, have a pivotal role during SARS-CoV-2 infection. IFN-Lambda response among individuals is heterogeneous and its association with COVID-19 symptoms severity needs to be further clarified. We analyzed the genotype frequencies of IFNL4 single nucleotide polymorphism (SNP) rs11322783 in patients with COVID-19 (n = 128), in comparison with a validated data set of European healthy controls (n = 14152). The IFNL4 SNP was also analyzed according to the haematological and clinical parameters of patients with COVID-19. The distributions of IFNL4 genotypes among SARS-CoV-2 positive patients [TT/TT 41.4% (n = 53), TT/ΔG 47.7% (n = 61) and ΔG/ΔG 10.9% (n = 14)] and healthy controls were comparable. Different levels of white blood cells (p = 0.036) and neutrophils (p = 0.042) were found in the IFNL4 different genotypes in patients with COVID-19; the ΔG/ΔG genotype was more represented in the groups with low white blood cells and neutrophils. There were no differences in major inflammation parameters (C-reactive protein, D-dimer, Albumin, and Lactate-dehydrogenase (LDH)] and survival rate according to the IFNL4 genotypes. In conclusion, although patients with COVID-19 did not exhibit a different distribution of the IFNL4 SNP, the ΔG/ΔG genotype was associated with a lower count of immune cell populations. These findings need to be confirmed in larger groups of patients with COVID-19 and the role of IFNL4 SNP needs to be also investigated in other respiratory viral infections.

CD46 Genetic Variability and HIV-1 Infection Susceptibility.

CD46 is the main receptor for complement protein C3 and plays an important role in adaptive immune responses. CD46 genetic variants are associated with susceptibility to several infectious and autoimmune diseases. Additionally, CD46 function can be subverted by HIV-1 to evade attack by complement, a strategy shared by viruses of other families. We sought to determine the association between CD46 gene variants and HIV-1 acquired through intravenous drug use (IDU) and sexual routes (n = 823). Study subjects were of European ancestry and were HIV-1 infected (n = 438) or exposed but seronegative (n = 387). Genotyping of the rs2796265 SNP located in the CD46 gene region was done by allele-specific real-time PCR. A meta-analysis merging IDU and sexual cohorts indicates that the minor genotype (CC) was associated with increased resistance to HIV-1 infection OR = 0.2, 95% CI (0.07-0.61), p = 0.004. The HIV-1-protective genotype is correlated with reduced CD46 expression and alterations in the ratio of CD46 mRNA splicing isoforms.