Instructions for the use of L-PRF in different clinical indications.

Autologous platelet concentrates (APCs) have demonstrated clear benefits across various clinical applications, including alveolar ridge preservation, guided tissue regeneration, guided bone regeneration, sinus floor elevation (both lateral window approach and transcrestal technique), endodontic surgery, the treatment of medication-related osteonecrosis of the jaw bones, and periodontal plastic surgery. To ensure an optimal clinical outcome, clinicians must adhere strictly to the protocol to prepare the APCs and, especially follow evidence-based surgical guidelines, often simple but crucial, to minimize the likelihood of errors. The majority of clinical trials reported on second-generation APCs [the leukocyte- and platelet-rich fibrin (L-PRF) family, including its modifications (A-PRF, A-PRF+, CGF, T-PRF, H-PRF, etc.)]. These second-generation APCs offer additional benefits compared to the first-generation APCs, making them the preferred choice for the development of clinical recommendations. These recommendations have been formulated through a meticulous examination of the available clinical data and the clinical experience of the authors of this paper.

Time to match; when do homologous chromosomes become closer?

In most eukaryotes, pairing of homologous chromosomes is an essential feature of meiosis that ensures homologous recombination and segregation. However, when the pairing process begins, it is still under investigation. Contrasting data exists in Mus musculus, since both leptotene DSB-dependent and preleptotene DSB-independent mechanisms have been described. To unravel this contention, we examined homologous pairing in pre-meiotic and meiotic Mus musculus cells using a three-dimensional fluorescence in situ hybridization-based protocol, which enables the analysis of the entire karyotype using DNA painting probes. Our data establishes in an unambiguously manner that 73.83% of homologous chromosomes are already paired at premeiotic stages (spermatogonia-early preleptotene spermatocytes). The percentage of paired homologous chromosomes increases to 84.60% at mid-preleptotene-zygotene stage, reaching 100% at pachytene stage. Importantly, our results demonstrate a high percentage of homologous pairing observed before the onset of meiosis; this pairing does not occur randomly, as the percentage was higher than that observed in somatic cells (19.47%) and between nonhomologous chromosomes (41.1%). Finally, we have also observed that premeiotic homologous pairing is asynchronous and independent of the chromosome size, GC content, or presence of NOR regions.

First report of Acanthamoebae spp. isolation from a volcanic mud spring in the Philippines.

Acanthamoebae spp. is considered highly adaptive. The present study aims to establish the occurrence of free-living amoebae, particularly Acanthamoebae, to exist in extreme environments such as volcanic mud springs. Fifty surface water samples were collected from mud springs (34 samples), and flat rocks (16 samples) were collected, processed, and cultured. After 14 days of incubation, 32 (64%) plates showed positive amoebic growth. Nineteen (55.8%) of these plates came from the mud spring collection site, while 13 (81.2%) samples are from flat rock sources. DNAs from positive samples were made to react to polymerase chain reaction (PCR) using primer sets JDP1 5'GGCCCAGATCGTTTACCGTGAA-3' and JDP2 5'TCTCACAAGCTGCTAGGGAGTCA-3' for cells that resemble Acanthamoebae. Sequencing and basic local alignment search tool (BLAST) revealed a 99% similarity of isolates to Acanthamoebae spp. Identification of Acanthamoebae spp that can survive in higher temperatures is important public health information. The existence of such isolates in the environment has dire health implications, which suggests revisitation of water treatment protocols. Detection of such organisms in environmental sources used for recreational purposes provides information to local and international tourists who frequent them. This will result in the mitigation of potential future infection.

Genetic Diversity of the Amur Tiger (Panthera tigris altaica): Are There Differences between the 20th and the Early 21st Centuries?

Polymorphism of nine microsatellite loci in the Sikhote-Alin tiger population was analyzed in the modern and recent historical periods, using blood, excrement, and museum bone samples. Tests for excess heterozygosity to determine whether the population went through a period of low abundance and a low value of the Garza-Williamson coefficient indicated that such events were highly probable to occur in both recent and earlier history. The mean effective population size Ne of a current sample was 34.4 (95% confidence interval 17-106.8). This fact is of great interest in the contest of conservation and restoration of endangered large cat species.

Assessment of Obsessive Thoughts About COVID-19 in 7 Latin American Countries: Structure and Measurement Invariance of the Obsession With COVID-19 Scale.

The present study aimed to evaluate the measurement invariance of the Obsession with COVID-19 Scale (OCS) among seven Latin American countries: Bolivia, Brazil, Cuba, El Salvador, Guatemala, Paraguay, and Uruguay. Although the OCS has been used in several countries and languages, there is a need for approaches that better integrate the cross-cultural equivalence of the scale. A total of 3185 people participated in the study. The results indicated the presence of a unidimensional structure and good reliability indices for the OCS in each country. The alignment method indicated that the OCS is an invariant measure of COVID-19 obsession among the populations of seven Latin American countries. The findings based on IRT analysis indicated that all OCS items had adequate discrimination and difficulty parameters. The findings contribute to the understanding of the internal structure of the scale in different countries at the same time, something that has been pending evaluation.

Chromosomal positioning in spermatogenic cells is influenced by chromosomal factors associated with gene activity, bouquet formation and meiotic sex chromosome inactivation.

Chromosome territoriality is not random along the cell cycle and it is mainly governed by intrinsic chromosome factors and gene expression patterns. Conversely, very few studies have explored the factors that determine chromosome territoriality and its influencing factors during meiosis. In this study, we analysed chromosome positioning in murine spermatogenic cells using three-dimensionally fluorescence in situ hybridization-based methodology, which allows the analysis of the entire karyotype. The main objective of the study was to decipher chromosome positioning in a radial axis (all analysed germ-cell nuclei) and longitudinal axis (only spermatozoa) and to identify the chromosomal factors that regulate such an arrangement. Results demonstrated that the radial positioning of chromosomes during spermatogenesis was cell-type specific and influenced by chromosomal factors associated to gene activity. Chromosomes with specific features that enhance transcription (high GC content, high gene density and high numbers of predicted expressed genes) were preferentially observed in the inner part of the nucleus in virtually all cell types. Moreover, the position of the sex chromosomes was influenced by their transcriptional status, from the periphery of the nucleus when its activity was repressed (pachytene) to a more internal position when it is partially activated (spermatid). At pachytene, chromosome positioning was also influenced by chromosome size due to the bouquet formation. Longitudinal chromosome positioning in the sperm nucleus was not random either, suggesting the importance of ordered longitudinal positioning for the release and activation of the paternal genome after fertilisation.

The RNA content of human sperm reflects prior events in spermatogenesis and potential post-fertilization effects.

Transcriptome analyses using high-throughput methodologies allow a deeper understanding of biological functions in different cell types/tissues. The present study provides an RNA-seq profiling of human sperm mRNAs and lncRNAs (messenger and long non-coding RNAs) in a well-characterized population of fertile individuals. Sperm RNA was extracted from twelve ejaculate samples under strict quality controls. Poly(A)-transcripts were sequenced and aligned to the human genome. mRNAs and lncRNAs were classified according to their mean expression values (FPKM: Fragments Per Kilobase of transcript per Million mapped reads) and integrity. Gene Ontology analysis of the Expressed and Highly Expressed mRNAs showed an involvement in diverse reproduction processes, while the Ubiquitously Expressed and Highly Stable mRNAs were mainly involved in spermatogenesis. Transcription factor enrichment analyses revealed that the Highly Expressed and Ubiquitously Expressed sperm mRNAs were primarily regulated by zinc-fingers and spermatogenesis-related proteins. Regarding the Expressed lncRNAs, only one-third of their potential targets corresponded to Expressed mRNAs and were enriched in cell-cycle regulation processes. The remaining two-thirds were absent in sperm and were enriched in embryogenesis-related processes. A significant amount of post-testicular sperm mRNAs and lncRNAs was also detected. Even though our study is solely directed to the poly-A fraction of sperm transcripts, results indicate that both sperm mRNAs and lncRNAs constitute a footprint of previous spermatogenesis events and are configured to affect the first stages of embryo development.

Experimental peri-implantitis around titanium implants with a chemically modified surface with a monolayer of multi-phosphonate molecules: a preclinical in vivo investigation.

OBJECTIVES: The purpose of this experimental in vivo investigation was to evaluate the influence of modifying the implant surface by adding a monolayer of multi-phosphonate molecules on the development of experimental peri-implantitis. MATERIAL AND METHODS: Eight beagle dogs received 5 tests and 5 control implants each following a split-mouth design 3 months after premolar and molar extraction. On the most mesial implant of each side, a 3-mm buccal dehiscence was artificially created. Experimental peri-implantitis was induced by silk ligatures over a 4-month period; after ligature removal, peri-implantitis was left to progress for another 4 months without plaque control. Clinical, histological, and radiographic outcomes were evaluated. RESULTS: Radiographically, both implant groups showed a similar bone loss (BL) at the end of the induction and progression phases. BL measured on the histological sections of the test and control groups was 3.14 ± 0.42 mm and 3.26 ± 0.28 mm, respectively; the difference was not statistically significant (p > 0.05). The remaining buccal bone to implant contact (bBIC) percentage of the test and control groups was 59.38 ± 18.62 and 47.44 ± 20.46%, respectively; the difference, however, was not statistically significant (p > 0.05). Bone loss observed at dehiscent sites compared to non-dehiscent ones showed no statistically significant difference (p > 0.05). CONCLUSIONS: Addition of a monophosphonate layer to a moderately rough implant surface did not affect development of experimental peri-implantitis. CLINICAL RELEVANCE: Influence of implant surface on peri-implantitis may condition implant selection by the clinician, especially on patients with disease risk factors. In that sense, monophosphate layer implants do not show higher peri-implantitis risk than control implants.

Neoantigen prediction and computational perspectives towards clinical benefit: recommendations from the ESMO Precision Medicine Working Group.

BACKGROUND: The use of next-generation sequencing technologies has enabled the rapid identification of non-synonymous somatic mutations in cancer cells. Neoantigens are mutated peptides derived from somatic mutations not present in normal tissues that may result in the presentation of tumour-specific peptides capable of eliciting antitumour T-cell responses. Personalised neoantigen-based cancer vaccines and adoptive T-cell therapies have been shown to prime host immunity against tumour cells and are under clinical trial development. However, the optimisation and standardisation of neoantigen identification, as well as its delivery as immunotherapy are needed to increase tumour-specific T-cell responses and, thus, the clinical efficacy of current cancer immunotherapies. METHODS: In this recommendation article, launched by the European Society for Medical Oncology (ESMO), we outline and discuss the available framework for neoantigen prediction and present a systematic review of the current scientific evidence. RESULTS: A number of computational pipelines for neoantigen prediction are available. Most of them provide peptide major histocompatibility complex (MHC) binding affinity predictions, but more recent approaches incorporate additional features like variant allele fraction, gene expression, and clonality of mutations. Neoantigens can be predicted in all cancer types with high and low tumour mutation burden, in part by exploiting tumour-specific aberrations derived from mutational frameshifts, splice variants, gene fusions, endogenous retroelements and other tumour-specific processes that could yield more potently immunogenic tumour neoantigens. Ongoing clinical trials will highlight those cancer types and combinations of immune therapies that would derive the most benefit from neoantigen-based immunotherapies. CONCLUSIONS: Improved identification, selection and prioritisation of tumour-specific neoantigens are needed to increase the scope of benefit from cancer vaccines and adoptive T-cell therapies. Novel pipelines are being developed to resolve the challenges posed by high-throughput sequencing and to predict immunogenic neoantigens.

Retinol-binding protein 4 (RBP4), a potential biomarker of frailty in HIV-infected people on stable antiretroviral therapy.

OBJECTIVES: A quantitative biomarker for identification of pre-frail and frail persons is still lacking. This study aimed to identify biomarker predictors of frailty in HIV-infected patients. METHODS: A cross-sectional study of HIV-infected patients who had been on antiretroviral therapy (ART) for at least 1 year and who presented an undetectable viral load (< 50 HIV-1 RNA copies/mL) at baseline was carried out. For each frail patient, up to four pre-frail and robust patients were randomly selected. The frailty status assessment was based on the five-item criteria described by Fried et al. Sociodemographic, anthropometric, biochemical and HIV-related characteristics were evaluated. Multiple potential biomarkers of frailty and a biological age biomarker were analysed. RESULTS: A total of 73 HIV-infected patients on ART for at least 1 year were evaluated. The patients were categorized as robust (n = 33), pre-frail (n = 32) and frail (n = 8) using the Fried criteria. All patients were on ART, with 100% undetectable viral load (< 50 copies/mL) at baseline. No significant differences in demographic, clinical or analytical characteristics were observed among patients in the different categories based on Fried criteria, with the exception of the veterans aging cohort study index (VACS). Similarly, no differences were observed in HIV-related characteristics, although nucleoside reverse transcriptase inhibitor (NRTI) use was less common in frail persons. The distribution of biomarker values varied according to frailty status, with frail persons having higher levels of interleukin (IL)-8, IL-18, CXC chemokine ligand 10 (CXCL10) and retinol-binding protein 4 (RBP4). In multivariable analysis, the assocation of frailty with RBP4 showed a tendency to statistical significance (odds ratio 1.0; 95% confidence interval 0.99-1.00; P < 0.05). CONCLUSIONS: Differential biomarker expression was present according to Fried status. Longitudinal studies will clarify the utility of these biomarkers as targets for diagnostic or therapeutic intervention.

A robust approach to ab initio cryo-electron microscopy initial volume determination.

Structural information from macromolecules provides key insights into the way complexes perform their biological functions. The reconstruction process leading to the final three-dimensional (3D) map is iterative and requires an initial volume to prime the refinement procedure. Particle images are aligned to this first reference and subsequently a new map is calculated from these particles. The accurate determination of an ab initio initial volume is still a challenging and open problem in cryo-electron microscopy (cryo-EM). Different algorithms are available to estimate an initial volume from the dataset. Some of these methods provide multiple candidate initial maps and users looking for robustness typically run different approaches. In this case, users arbitrarily evaluate the different obtained candidate maps, as we lack robust methods to objectively assess the accuracy of initial references. This workflow is subjective and error-prone preventing implementation of high-throughput data processing procedures. In this work, we present a robust method to determine the best initial map or maps from a set of ab initio initial volumes obtained from one or multiple different approaches. The method is based on evaluating multiple small subsets of candidate initial volumes and particle images through reference-based 3D classifications. Obtained 3D classes of accurate initial maps will result majoritarian and the respective attracted particles will be aligned with high angular accuracies. We have tested the proposed approach with structurally homogeneous and heterogeneous datasets providing satisfactory results with both type of data.

Differences in the cluster of depressive symptoms between subjects with type 2 diabetes and individuals with a major depressive disorder and without diabetes.

BACKGROUND: Depressive disorder encompasses a wide spectrum of somatic and psychological symptoms. It is not known whether there are differences regarding the cluster of depressive symptomatology between subjects with depression with and without T2DM. PURPOSE: To explore whether the cluster of depression that prevails among depressive subjects with T2DM differs from individuals with depression, but without T2DM. METHODS: 87 T2DM patients with a pathological Beck Depression Inventory test (BDI) were compared with 50 age- and gender-matched individuals with a major depressive disorder. All 21 items expressed in the BDI were compared between the two groups. RESULTS: The score obtained after administering the BDI was comparable between patients with T2DM and significant depressive symptoms and the control group (18.8 ± 2.7 vs 18.9 ± 3.4; p = 0.9). Subjects with T2DM had higher scores compared with the control group in the following items: sadness (1.4 ± 0.9 vs 0.9 ± 0.9; p = 0.011), difficulty in concentration (1.3 ± 0.8 vs 0.8 ± 0.8; p = 0.01), indecisiveness (1.1 ± 0.8 vs 0.5 ± 0.9; p = 0.012), worries about their health (1.3 ± 0.9 vs 0.6 ± 0.9; p < 0.0001), fatigue (1.2 ± 0.6 vs 0.8 ± 0.7; p = 0.003) and loss of sexual appetite (2.7 ± 0.6 vs 1.2 ± 1.3; p = 0.0001). Suicidal ideation was significantly lower among subjects with T2DM compared with the control group (0.1 ± 0.3 vs 0.6 ± 0.8; p = 0.0001). CONCLUSIONS: Subjects with T2DM and a positive screening for depression presented a different cluster of depression compared with depressed subjects without T2DM, with a predominance of somatic-biological depressive symptoms rather than psychological-cognitive cluster and negative emotions, such as suicidal ideation.

Blind estimation of DED camera gain in Electron Microscopy.

The introduction of Direct Electron Detector (DED) videos in the Electron Microscope field has boosted Single Particle Analysis to a point in which it is currently considered to be a key technique in Structural Biology. In this article we introduce an approach to estimate the DED camera gain at each pixel from the movies themselves. This gain is needed to have the set of recorded frames into a coherent gray level range, homogeneous over the whole image. The algorithm does not need any other input than the DED movie itself, being capable of providing an estimate of the camera gain image, helping to identify dead pixels and cases of incorrectly calibrated cameras. We propose the algorithm to be used either to validate the experimentally acquired gain image (for instance, to follow its possible change over time) or to verify that there is no residual gain image after experimentally correcting for the camera gain. We show results for a number of DED camera models currently in use (DE, Falcon II, Falcon 3, and K2).

Using Scipion for stream image processing at Cryo-EM facilities.

Three dimensional electron microscopy is becoming a very data-intensive field in which vast amounts of experimental images are acquired at high speed. To manage such large-scale projects, we had previously developed a modular workflow system called Scipion (de la Rosa-Trevín et al., 2016). We present here a major extension of Scipion that allows processing of EM images while the data is being acquired. This approach helps to detect problems at early stages, saves computing time and provides users with a detailed evaluation of the data quality before the acquisition is finished. At present, Scipion has been deployed and is in production mode in seven Cryo-EM facilities throughout the world.

Subclinical cardiovascular disease in patients starting contemporary protease inhibitors.

OBJECTIVES: The aim of the study was to assess changes in and factors associated with anatomical [carotid artery intima-media thickness (CIMT)] and functional (arterial stiffness) markers of subclinical cardiovascular disease progression in antiretroviral-naïve patients starting triple combination antiretroviral therapy containing contemporary protease inhibitors. METHODS: This was a planned substudy of the ATADAR (Metabolic Effects of Atazanavir/Ritonavir Versus Darunavir/Ritonavir in Combination With Tenofovir/Emtricitabine in naïve HIV-1 Infected Patients) clinical trial (ClinicalTrials.gov identifier NCT01274780). ATADAR is a multicentre, randomized, open-label clinical trial comparing the effects of ritonavir-boosted atazanavir and darunavir, both with tenofovir/emtricitabine, in antiretroviral-naïve HIV-infected patients. Common CIMT and aortic augmentation index (AIx@75) were measured at baseline and after 12 months of follow-up. Antiretroviral treatment, traditional cardiovascular risk factors and HIV-related factors were assessed as potential predictors of CIMT and Aix@75 changes using linear regression analysis. RESULTS: Thirty-three patients were included in this pilot study. While CIMT significantly increased in the pooled population [median (interquartile range (IQR)) 68 (-13, 128) µm; P = 0.0511], AIx@75 did not [median (IQR) 1 (-6, 5)%; P = 0.8964]. Patients on darunavir showed a trend to faster CIMT progression than those on atazanavir [median change (IQR) 117 (-2, 143) vs. -6 (-58, 89) µm, respectively; P = 0.0917]. However, after adjustment in the multivariate analysis, a higher baseline Framingham score was the only factor associated with CIMT progression (coefficient 16.02; 95% confidence interval -1.04, 33.08; P = 0.064). AIx@75 change was not associated with any baseline factor. CONCLUSIONS: CIMT was a more sensitive marker of subclinical vascular disease progression than arterial stiffness in antiretroviral-naïve patients starting antiretroviral therapy with contemporary protease inhibitors. Classical risk factors but not antiretroviral therapy were associated with faster CIMT progression.

Brain natriuretic peptide serum levels in periodontitis.

BACKGROUND AND OBJECTIVE: N-terminal-pro-brain natriuretic peptide (NT-proBNP) is expressed during inflammation and considered to be a biomarker of cardiovascular disease (CVD). In the last decade, evidence has suggested that periodontitis is associated with CVD. However, little is known of the potential role of this peptide in periodontal disease. The aims of this study were to examine whether the levels of NT-proBNP in serum are increased in periodontal disease and if there is a relationship to severity of periodontitis. MATERIAL AND METHODS: A case-control study was carried out, in which serum samples were collected from 40 patients with periodontitis and from 40 nonperiodontitis individuals. Full periodontal examination was performed in all subjects. Demographic information, and clinical and history of certain diseases were also recorded. Determinations of serum NT-proBNP and high-sensitivity C-reactive protein concentrations were carried out in an independent laboratory. RESULTS: The levels of NT-proBNP in serum were significantly higher in patients with periodontitis compared with controls (87.9 pg/mL vs 29.9 pg/mL, P < .0001). In addition, as periodontal disease progressed, the levels of NT-proBNP increased. Multivariable regression analysis showed that the periodontal inflamed surface area, a measure of periodontal inflammation and disease activity, was the only periodontal parameter significantly associated with elevated concentrations of NT-proBNP in serum (R2  = .777, P < .0001). CONCLUSION: In periodontitis, increased serum NT-proBNP levels are observed in comparison with individuals without periodontitis. Moreover, the greater the degree of periodontal destruction, the higher the levels of NT-proBNP in serum.

Adalimumab for Induction of Histological Remission in Moderately to Severely Active Ulcerative Colitis.

BACKGROUND: Histological remission represents a target distinct from endoscopic healing in ulcerative colitis (UC) and seems a better predictor of clinical outcomes. AIMS: The aim of this study was to assess the ability of adalimumab to achieve histological remission in UC patients. METHODS: Single-center, retrospective, open-label study of patients treated with adalimumab. Eligible patients were anti-TNF naïve adults with moderately to severely active UC. The Mayo score including endoscopy was performed at baseline and weeks 8 and 52. Histological activity was scored using the Geboes Index. The primary endpoint was histological remission, defined as a Geboes grade ≤ 3.0, at week 52. RESULTS: We included 34 patients. At week 8, 6 of 34 patients (17.6%) achieved histological remission. At week 52, 9 patients (26.5%, intention to treat; 31%, per protocol) had histological remission. Patients had a significant and progressive reduction in the most severe subgrades of Geboes Index from baseline at weeks 8 and 52. At weeks 8 and 52, 50 and 61.8% of patients achieved mucosal healing (Mayo endoscopic subscore 0-1). All patients who achieved histological remission also had mucosal healing. At week 8, 85.3 and 20.6% of patients achieved clinical response (decrease in Mayo score ≤ 3 points) or remission (Mayo score ≤ 2), respectively. At week 52, the corresponding values were 67.6 and 52.9%, respectively. At week 52, agreement between histological remission and mucosal healing was fair (kappa 0.293). Agreement between histological remission and Mayo endoscopic subscore 0 was good (kappa 0.71). CONCLUSIONS: Adalimumab was able to achieve histological remission in anti-TNF naïve patients with moderately to severely active UC.

Interstitial lung disease in systemic sclerosis: data from the spanish scleroderma study group.

OBJECTIVES: To evaluate the clinical characteristics of patients with interstitial lung disease (ILD) in the setting of a large cohort of systemic sclerosis (SSc) patients, and to analyse the differences according to the SSc subtype (following the modification of classification criteria of the American College of Rheumatology for SSc proposed by LeRoy and Medsger), factors are associated with moderate-to-severe impairment of lung function, as well as mortality and causes of death. METHODS: A descriptive study was performed, using the available data from the Spanish Scleroderma Study Group. RESULTS: Twenty-one referral centers participated in the registry. By April 2014, 1374 patients with SSc had been enrolled, and 595 of whom (43%) had ILD: 316 (53%) with limited cutaneous SSc (lcSSc), 240 (40%) with diffuse cutaneous SSc (dcSSc), and 39 (7%) with SSc sine scleroderma (ssSSc). ILD in the lcSSc and the ssSSc subsets tended to develop later, and showed a less impaired forced vital capacity (FVC) and a ground glass pattern on high-resolution computed tomography (HRCT) less frequently, compared with the dcSSc subset. Factors related to an FVC < 70% of predicted in the multivariate analysis were: dcSSc, positivity to anti-topoisomerase I antibodies, a ground glass pattern on HCRT, an active nailfold capillaroscopy pattern, lower DLco, older age at symptoms onset, and longer time between symptoms onset and ILD diagnosis. Finally, SSc-associated mortality and ILD-related mortality were highest in dcSSc patients, whereas that related to pulmonary arterial hypertension was highest in those with lcSSc-associated ILD. CONCLUSIONS: Our study indicates that ILD constitutes a remarkable complication of SSc with significant morbidity and mortality, which should be borne in mind in all three subgroups (lcSSc, dcSSc, and ssSSc).

Integrase strand-transfer inhibitor polymorphic and accessory resistance substitutions in patients with acute/recent HIV infection.

OBJECTIVES: The most recent guidelines suggest using integrase strand-transfer inhibitors (InSTIs) as the preferred antiretroviral regimens for naive HIV-infected individuals. However, resistance to InSTIs is not monitored in many centres at baseline. This study aimed to evaluate the prevalence of InSTI resistance substitutions in newly diagnosed patients with acute/recent HIV infection. METHODS: Genotypic drug resistance tests were performed in all consecutive patients prospectively enrolled with a documented infection of <6 months, from 12 May 2015 to 12 May 2016. Sequences were obtained by high-throughput sequencing. RESULTS: Five out of 36 consecutive patients (13.89%, 95% CI = 4.67-29.5) with acute/recent HIV infection were detected to have strains carrying InSTI polymorphisms or substitutions conferring low-level resistance to raltegravir and elvitegravir. Four patients had the 157Q polymorphism and one patient had the Q95K substitution. All cases were MSM patients infected with subtype B strains. Viral loads ranged from 2.92 to 6.95 log10 copies/mL. In all cases, the mutational viral load was high. Three patients initiated dolutegravir-based regimens and became undetectable at first viral load control. There were no major viral or epidemiological differences when compared with patients without InSTI substitutions. CONCLUSIONS: Although signature InSTI substitutions (such as Y143R/C, N155H or Q148K/R/H) were not detected, polymorphisms and substitutions conferring low-level resistance to raltegravir and elvitegravir were frequently found in a baseline genotypic test. All cases were infected with subtype B, the most frequent in Europe. In the context of primary HIV infection, virological response should be carefully monitored to evaluate the impact of these InSTI polymorphisms and substitutions.