Biology subjects

Castro, A.

Publications and source records attributed to Castro, A..

At least 37 records · Page 2Linked to original sources

bioRxiv2024

Integrated germline and somatic features reveal divergent immune pathways driving ICB response

Immune Checkpoint Blockade (ICB) has revolutionized cancer treatment, however mechanisms determining patient response remain poorly understood. Here we used machine learning to predict ICB response from germline and somatic biomarkers and interpreted the learned model to uncover putative mechanisms driving superior outcomes. Patients with higher T follicular helper infiltrates were robust to defects in the class-I Major Histocompatibility Complex (MHC-I). Further investigation uncovered different ICB responses in MHC-I versus MHC-II neoantigen reliant tumors across patients. Despite similar response rates, MHC-II reliant responses were associated with significantly longer durable clinical benefit (Discovery: Median OS=63.6 vs. 34.5 months P=0.0074; Validation: Median OS=37.5 vs. 33.1 months, P=0.040). Characteristics of the tumor immune microenvironment reflected MHC neoantigen reliance, and analysis of immune checkpoints revealed LAG3 as a potential target in MHC-II but not MHC-I reliant responses. This study highlights the value of interpretable machine learning models in elucidating the biological basis of therapy responses. Statement of SignificanceImmune checkpoint blockade works only in a fraction of patients for reasons that are still not fully understood. Our study reveals heterogeneity in the immune responses of ICB responders that correlates with characteristics of the neoantigen landscape. This heterogeneity is accompanied by differences in the duration of clinical benefit as well as by differences as to which immune checkpoint gene serves as a biomarker of ICB response. These findings suggest possible new strategies for improving ICB responses. HighlightsO_LIWe used machine learning to study ICB response across 708 patients from 8 studies across 3 tumor types (melanoma, RCC, and NSCLC). C_LIO_LICombining germline and somatic features improves prediction of ICB response C_LIO_LIInteractions between germline and somatic features reveal mechanisms contributing to ICB sensitivity. C_LIO_LIMHC-I vs. MHC-II reliance implicates LAG3 as a prognostic biomarker in the context of CD4 T cell driven responses. C_LIO_LIMHC-II neoantigen reliant responses provide superior durable clinical benefit in response to ICB. C_LI

cancer biology↗

bioRxiv2023

A Novel Aberrantly Spliced Gain-of-Function NT5C2 Isoform Contributes to Thiopurine Resistance in Acute Lymphoblastic Leukemia

Relapsed or refractory B-cell acute lymphoblastic leukemia (B-ALL) is a major cause of pediatric cancer-related deaths. Relapse-specific mutations do not account for all chemotherapy failures in B- ALL patients, suggesting additional mechanisms of resistance. By mining RNA-seq datasets of paired diagnostic/relapse pediatric B-ALL samples, we discovered pervasive alternative splicing (AS) patterns linked to relapse and affecting drivers of resistance to glucocorticoids, anti-folates, and thiopurines. Most splicing variations represented cassette exon skipping, "poison" exon inclusion, and intron retention, phenocopying well-documented loss-of-function mutations. In contrast, relapse-associated AS of NT5C2 mRNA yielded an isoform with the functionally uncharacterized in-frame exon 6a. Incorporation of the 8-amino acid sequence SQVAVQKR into this enzyme created a putative phosphorylation site and resulted in elevated nucleosidase activity, which is a known consequence of gain-of-function mutations in NT5C2 and a common determinant of 6-mercaptopurine (6-MP) resistance. Consistent with this finding, NT5C2ex6a and the R238W hotspot variant conferred comparable levels of resistance to 6-MP in B-ALL cells both in vitro and in vivo. Furthermore, both the NT5C2ex6a and R238W variants induced collateral sensitivity to the inosine monophosphate dehydrogenase (IMPDH) inhibitor mizoribine. These results ascribe an important role for splicing perturbations in chemotherapy resistance in relapsed B-ALL and suggest that IMPDH inhibitors, including the commonly used immunosuppressive agent mycophenolate mofetil, could be a valuable therapeutic option for treating thiopurine-resistant leukemias.

cancer biology↗

bioRxiv2023

Cyclin A/cdk activity and FAM122A-dependent inhibition of PP2A-B55 are essential to trigger mitosis.

Entry into mitosis has been classically attributed to the activation of cyclin B/cdk1 amplification loop by a partial pool of this kinase that becomes active at the end of G2. However, how this pool is activated is still unknown. Here we discovered a new role of the recently identified PP2A-B55 inhibitor FAM122A in triggering mitotic entry. Accordingly, the depletion of the orthologue of FAM122A in C. elegans, prevents entry into mitosis in germline stem cells. Moreover, our data in Xenopus egg extract strongly supports that FAM122A-dependent inhibition of PP2A-B55 could be the initial event promoting mitotic entry. The inhibition of this phosphatase allows the subsequent phosphorylation of first mitotic substrates by cyclin A/cdk resulting in cyclin B/cdk1 and Greatwall (Gwl) activation. However, interestingly, from Gwl activation, Arpp19/ENSA become phosphorylated and compete with FAM122A promoting its dissociation from PP2A-B55 and taking over its inhibition until the end of mitosis.

cell biology↗

bioRxiv2023

Melanoma clonal subline analysis uncovers heterogeneity-driven immunotherapy resistance mechanisms

Intratumoral heterogeneity (ITH) can promote cancer progression and treatment failure, but the complexity of the regulatory programs and contextual factors involved complicates its study. To understand the specific contribution of ITH to immune checkpoint blockade (ICB) response, we generated single cell-derived clonal sublines from an ICB-sensitive and genetically and phenotypically heterogeneous mouse melanoma model, M4. Genomic and single cell transcriptomic analyses uncovered the diversity of the sublines and evidenced their plasticity. Moreover, a wide range of tumor growth kinetics were observed in vivo, in part associated with mutational profiles and dependent on T cell-response. Further inquiry into melanoma differentiation states and tumor microenvironment (TME) subtypes of untreated tumors from the clonal sublines demonstrated correlations between highly inflamed and differentiated phenotypes with the response to anti-CTLA-4 treatment. Our results demonstrate that M4 sublines generate intratumoral heterogeneity at both levels of intrinsic differentiation status and extrinsic TME profiles, thereby impacting tumor evolution during therapeutic treatment. These clonal sublines proved to be a valuable resource to study the complex determinants of response to ICB, and specifically the role of melanoma plasticity in immune evasion mechanisms.

cancer biology↗

bioRxiv2022

A deficiency screen of the 3rd chromosome for dominant modifiers of the Drosophila ER integral membrane protein, Jagunal

The mechanism surrounding chromosome inheritance during cell division has been well documented, however, organelle inheritance during mitosis is less understood. Recently, the Endoplasmic Reticulum (ER) has been shown to reorganize during mitosis, dividing asymmetrically in proneuronal cells prior to cell fate selection, indicating a programmed mechanism of inheritance. ER asymmetric partitioning in proneural cells relies on the highly conserved ER integral membrane protein, Jagunal (Jagn). Knockdown of Jagn in the compound Drosophila eye displays a pleotropic rough eye phenotype in 48% of the progeny. To identify genes involved in Jagn dependent ER partitioning pathway, we performed a dominant modifier screen of the 3rd chromosome for enhancers and suppressors of this Jagn RNAi-induced rough eye phenotype. We screened through 181 deficiency lines covering the 3L and 3R chromosomes and identified 12 suppressors and 10 enhancers of the Jagn RNAi phenotype. Based on the functions of the genes covered by the deficiencies, we identified genes that displayed a suppression or enhancement of the Jagn RNAi phenotype. These include Division Abnormally Delayed (Dally), an heparan sulfate proteoglycan, the {gamma}-secretase subunit Presenilin, and the ER resident protein Sec63. Based on our understanding of the function of these targets, there is a connection between Jagn and the Notch signaling pathway. Further studies will elucidate the role of Jagn and identified interactors within the mechanisms of ER partitioning during mitosis.

genetics↗

bioRxiv2022

Formulating a TMEM176B blocker in nanoparticles uncouples its paradoxical roles in innate and adaptive antitumoral immunity.

The immunoregulatory cation channel TMEM176B plays a dual role in tumor immunity. On one hand, TMEM176B promotes antigen cross-presentation to CD8+ T cells by regulating phagosomal pH in dendritic cells (DCs). On the other hand, TMEM176B inhibits NLRP3 inflammasome activation through ionic mechanisms in DCs, monocytes and macrophages. Moreover, the TMEM176B blocker BayK8644 controls tumor progression through mechanisms involving inflammasome activation in prophylactic but not in therapeutic protocols. We speculated that the limited therapeutic efficacy of the compound may be linked to its potential capacity to inhibit antigen cross-presentation. Here we show that free BayK8644 inhibits antigen cross-presentation by splenic DCs. To prevent such inhibition, we reasoned that formulating BayK8644 in nanoparticles may delay the release of the compound in endosomes. Avoiding TMEM176B inhibition during the first 30 minutes of nanoparticle internalization by DCs may allow efficient cross-presentation to occur during this critical time frame. Indeed, we observed that NP-PEG-BayK8644 did not inhibit antigen cross-presentation, in contrast to the free compound. Moreover, NP-PEG-BayK8644 triggered inflammasome activation in a Tmem176b-dependent manner. We then injected eNP-PEG or NP-PEG-BayK8644 to mice bearing established tumors. NP-PEG-BayK8644 significantly controlled tumor growth and mice survival, as compared to eNP-PEG and free BayK8644, in a Tmem176b-dependent manner in mouse melanoma and lymphoma tumors. Responding animals treated with NP-PEG-BayK8644 showed reinforced tumor infiltration by total and tumor-specific CD8+ T cells. Overall, we rationally developed a formulating method of BayK8644 that improves its anti-tumoral therapeutic efficacy by uncoupling the dual role of TMEM176B on innate and adaptive immunity.

immunology↗

bioRxiv2022

Cetacean "gas-bubble thromboembolic polycystic liver disease": "Budd-Chiari-like syndrome" in dolphins?

Nearly two decades ago, pathologic examination results suggested acoustic factors, such as mid-frequency active naval military sonar (MFAS) could be the cause of acute decompression-like sickness in stranded beaked whales. Acute systemic gas embolism in these beaked whales was published together with enigmatic cystic liver lesions (CLL), characterized by intrahepatic encapsulated gas-filled cysts, tentatively interpreted as "gas-bubble" lesions in various cetacean species. Here we provide a pathologic reinterpretation of CLL in cetaceans. From 1,200 cetaceans necropsied, CLL were only observed in striped dolphins (Stenella coeruleoalba), with a low prevalence (2%), and recapitulated pathologic features of Budd-Chiari syndrome in humans. Our results strongly suggest that CLL are the result of the combination of pre-existing or concomitant hepatic vascular disorder (e.g., severe hepatobiliary trematodiasis) superimposed and exacerbated by gas bubbles, and clearly differ from acute systemic gas embolism in stranded beaked whales linked to MFAS.

pathology↗

bioRxiv2021

Electrical signature of heterogeneous human mesenchymal stem cells

Human mesenchymal stem cells (hMSCs) have gained traction in transplantation therapy due to their immunomodulatory, paracrine, immune-evasive, and multipotent differentiation potential. Given the heterogeneous nature of hMSCs, therapeutic treatments and robust in vivo and in vitro experiments require additional biomarkers to ensure reproducibility when using these stem cells. In this work, we utilized dielectrophoresis (DEP), a label-free electrokinetic phenomenon, to investigate and quantify the heterogeneity of hMSCs derived from the bone marrow (BM) and adipose tissue (AD). Through computer simulation, we identified that the transient slope of the DEP force spectra can be used as a metric of heterogeneity. The electrical properties of BM-hMSCs were compared to homogeneous mouse fibroblasts (NIH-3T3), human fibroblasts (WS1), and human embryonic kidney cells (HEK-293). BM-hMSCs DEP profile was most different from HEK-293 cells. We compared the DEP profiles of BM-hMSCs and AD-hMSCs and found they have similar membrane capacitances, differing cytoplasm conductivity, and transient slopes. Inducing both populations to differentiate into adipocyte and osteocyte cells revealed they behave differently in response to differentiation-inducing cytokines. Histology and RT-qPCR analyses of the differentiation-related genes revealed differences in heterogeneity between BM-hMSCs and AD-hMSCs. The differentiation profiles correlate well with the DEP profiles developed and indicate that these BM-hMSCs have higher differentiation potential than AD-hMSCs. Our results demonstrate using DEP, membrane capacitance, cytoplasm conductivity, and transient slope can uniquely characterize the inherent heterogeneity of hMSCs to guide robust and reproducible stem cell transplantation therapies.

bioengineering↗

bioRxiv2021

Immunogenic potential of neopeptides depends on parent protein subcellular location

Antigen presentation via the major histocompatibility complex (MHC) is essential for anti-tumor immunity, however the rules that determine what tumor-derived peptides will be immunogenic are still incompletely understood. Here we investigate whether protein subcellular location driven constraints on accessibility of peptides to the MHC associate with potential for peptide immunogenicity. Analyzing over 380,000 peptides from studies of MHC presentation and peptide immunogenicity, we find clear spatial biases in both eluted and immunogenic peptides. We find that including parent protein location improves prediction of peptide immunogenicity in multiple datasets. In human immunotherapy cohorts, location was associated with response to a neoantigen vaccine, and immune checkpoint blockade responders generally had a higher burden of neopeptides from accessible locations. We conclude that protein subcellular location adds important information for optimizing immunotherapies. HighlightsO_LIPeptides eluted from class I and II MHC reflect biases in the subcellular location of the parent proteins C_LIO_LIAn embedding-based indicator of parent protein location improves prediction of neoepitope immunogenicity and immunotherapy response C_LIO_LINeoepitope location improves estimation of effective neoantigen burden and stratification of potential for immunotherapy response C_LI

bioinformatics↗

bioRxiv2021

Structure selected RBM immunogens prime polyclonal memory responses that neutralize SARS-CoV-2 variants of concern

Successful control of the COVID-19 pandemic depends on vaccines that prevent transmission. The full-length Spike protein is highly immunogenic but the majority of antibodies do not target the virus: ACE2 interface. In an effort to concentrate the antibody response to the receptor-binding motif (RBM) we generated a series of conformationally-constrained immunogens by inserting solvent-exposed RBM amino acid residues into hypervariable loops of an immunoglobulin molecule. Priming C57BL/6 mice with plasmid (p)DNA encoding these constructs yielded a rapid memory response to booster immunization with recombinant Spike protein. Immune sera antibodies bound strongly to the purified receptor-binding domain (RBD) and Spike proteins. pDNA primed for a consistent response with antibodies efficient at neutralizing authentic WA1 virus and two variants of concern (VOC), B.1.351 and B.1.617.2. These findings demonstrate that immunogens built on structure selection can focus the response to conserved sites of vulnerability shared between wildtype virus and VOCs and induce neutralizing antibodies across variants.

immunology↗

bioRxiv2021

Autoimmune Alleles at the Major Histocompatibility Locus Modify Melanoma Susceptibility

Autoimmunity and cancer represent two different aspects of immune dysfunction. Autoimmunity is characterized by breakdowns in immune self-tolerance, while impaired immune surveillance can allow for tumorigenesis. The class I major histocompatibility complex (MHC-I), which displays derivatives of the cellular peptidome for immune surveillance by CD8+ T cells, serves as a common genetic link between these conditions. As melanoma-specific CD8+ T-cells have been shown to target melanocyte-specific peptide antigens more often than melanoma-specific antigens, we investigated whether vitiligo and psoriasis predisposing MHC-I alleles conferred a melanoma protective effect. In individuals with cutaneous melanoma from both The Cancer Genome Atlas (N = 451) and an independent validation cohort (N = 586), MHC-I autoimmune allele carrier status was significantly associated with a later age of melanoma diagnosis. Furthermore, MHC-I autoimmune allele carriers were significantly associated with decreased risk of developing melanoma in the Million Veterans Program cohort (OR = 0.962, p = 0.024). Existing melanoma polygenic risk scores (PRS) did not predict autoimmune allele carrier status, suggesting these alleles provide new risk-relevant information. Mechanisms of autoimmune protection were neither associated with improved melanoma-driver mutation association nor improved gene-level conserved antigen presentation relative to common alleles (population frequency > 1%). However, autoimmune alleles showed higher affinity relative to common alleles for particular windows of melanocyte conserved antigens suggesting a potential relationship between antigen processing, binding, and cell-surface presentation. Overall, this study presents evidence that MHC-I autoimmune risk alleles modulate melanoma risk unaccounted for by current PRS.

cancer biology↗

bioRxiv2021

Structure and dynamics of FCHo2 docking on membranes

Clathrin-mediated endocytosis (CME) is a central trafficking pathway in eukaryotic cells regulated by phosphoinositides. The plasma membrane phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) plays an instrumental role in driving CME initiation. The F-BAR domain only protein 1 and 2 complex (FCHo1/2) is among the early proteins that reach the plasma membrane, but the exact mechanisms triggering its recruitment remains elusive. Here, we show the molecular dynamics of FCHo2 self-assembly on membranes by combining bottom-up synthetic approaches on in vitro and cellular membranes. Our results indicate that PI(4,5)P2 domains assist FCHo2 docking at specific membrane regions, where it self-assembles into ring-like shape protein patches. We show that binding of FCHo2 on cellular membranes promotes PI(4,5)P2 clustering at the boundary of cargo receptors and that this accumulation enhances clathrin assembly. Thus, our results provide a mechanistic framework that could explain the recruitment of early PI(4,5)P2-interacting proteins at endocytic sites.

biophysics↗

bioRxiv2021

Germline variants that influence the tumor immune microenvironment also drive response to immunotherapy

With the continued promise of immunotherapy as an avenue for treating cancer, understanding how host genetics contributes to the tumor immune microenvironment (TIME) is essential to tailoring cancer screening and treatment strategies. Approaches that intersect SNP modifiers of molecular phenotype, such as gene expression, with disease phenotypes have shown promise for implicating causal genetic factors. Here we evaluated 194 literature-curated TIME associations and 890 associations detected with 157 immune phenotype (IP) components found using genotypes from over 8,000 individuals in The Cancer Genome Atlas. Of these 1084, 233 associations comprising 219 unique TIME-SNPs were also cancer relevant, associating with cancer risk, survival, and/or immunotherapy treatment response. Many cancer relevant TIME-SNPS overlapped regions of active transcription, and were associated with gene expression in specific immune cell subsets, such as macrophages and dendritic cells. TIME-SNPs associated with cancer risk and response to immunotherapy implicated genes involved in antigen presentation, especially by antigen presenting cells. The strongest associations with survival were with PD-L1 and CTLA-4, suggesting that SNPs modifying the potential for immune evasion could contribute to disease progression. To assess whether our approach could reveal novel cancer immunotherapy targets, we inhibited CTSS, a gene implicated by cancer risk and immunotherapy response-associated TIME-SNPs; CTSS inhibition resulted in slowed tumor growth and extended survival in vivo. These results validate the potential of cancer relevant TIME-SNPs to implicate target genes for countering immune suppressive characteristics of the TIME and set the stage for future host genetics analysis integrating germline variation and TIME characteristics. SignificanceA systematic screen for common germline variants associated with the tumor immune microenvironment across > 8000 tumors reveals novel cancer risk factors and targets for immunotherapy.

cancer biology↗

bioRxiv2021

Potential global impact of the N501Y mutation on MHC-II presentation and immune escape

The B.1.1.7 SARS-CoV-2 variant, characterized by the N501Y mutation, is rapidly emerging, raising concerns about its effectiveness on natural as well as vaccine-induced adaptive viral immunity at the population level. Since CD4 T cell responses are of critical importance to the antibody response, we examined the global effects of N501Y mutation on MHC-II presentation compared to the N501 wildtype and found poorer presentation across the majority of MHC-II alleles. This suggests that the N501Y mutation may not only diminish binding of antibodies to the RBD but also interfere with their production by weakening the cooperation between T and B cells, facilitating immune escape.

bioinformatics↗

bioRxiv2020

MHC-II constrains the natural neutralizing antibody response to the SARS-CoV-2 spike RBM in humans

SARS-CoV-2 antibodies develop within two weeks of infection, but wane relatively rapidly post-infection, raising concerns about whether antibody responses will provide protection upon re-exposure. Here we revisit T-B cooperation as a prerequisite for effective and durable neutralizing antibody responses centered on a mutationally constrained RBM B cell epitope. T-B cooperation requires co-processing of B and T cell epitopes by the same B cell and is subject to MHC-II restriction. We evaluated MHC-II constraints relevant to the neutralizing antibody response to a mutationally-constrained B cell epitope in the receptor binding motif (RBM) of the spike protein. Examining common MHC-II alleles, we found that peptides surrounding this key B cell epitope are predicted to bind poorly, suggesting a lack MHC-II support in T-B cooperation, impacting generation of high-potency neutralizing antibodies in the general population. Additionally, we found that multiple microbial peptides had potential for RBM cross-reactivity, supporting previous exposures as a possible source of T cell memory. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=193 SRC="FIGDIR/small/424449v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@d332ccorg.highwire.dtl.DTLVardef@1ac1a95org.highwire.dtl.DTLVardef@5688dorg.highwire.dtl.DTLVardef@1133d83_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2020

Genome-wide identification, characterization and expression analysis of the Bcl-2 associated athanogene (BAG) gene family in Physcomitrium patens

The Bcl-2-associated athanogene (BAG) family is an evolutionarily conserved, multifunctional group of co-chaperones regulators that modulate a number of diverse processes. Plant BAG genes were identified to play an extensive role in processes of programmed cell death (PCD) ranging from growth and development to stress responses. In this study, we identified BAG genes from different photosynthetic organisms in order to gather evolutionary insights on these proteins followed by an in silico characterization of the BAG family in the bryophyte Physcomitrium patens. Ten putative PpBAGs harbouring a characteristic BAG domain were grouped into two subfamilies based on the presence of additional conserved domains and phylogenetic distances. Group I consisted of PpBAG4 and PpBAG5, containing an additional ubiquitin-like domain, and PpBAG10 with only the BAG domain. Group II consisted of PpBAG1-3 and PpBAG6-9, containing a calmodulin-binding IQ motif, a novel feature associated with plant BAG proteins. Interestingly, PpBAG9 exhibits an EF-Hand domain, not reported to date in this class of proteins. Caspase cleavage sites in PpBAG1, PpBAG3, PpBAG4-5 and PpBAG9 were predicted. In silico analysis of BAG genes revealed the presence of stress responsive elements, and a stress-regulated expression pattern which appears to be dependent on specifically organized promoter regulatory elements. According to our analyses, the present data suggest that some members of P. patens BAG gene family may play a role in heat responses, autophagy and pathogen immunity. Further studies are required to unveil the role of specific members of this gene family in PCD and stress responses in P. patens. Key messageGenome-wide identification and phylogenetic relationships combined with in silico gene-expression profiling and protein-interaction analysis of PpBAGs in Physcomitrium patens, highlight the importance of a particular set in stress tolerance.

plant biology↗

bioRxiv2020

Biocontrol potential of grapevine endophytes against grapevine trunk pathogens

Grapevine Trunk Diseases (GTDs) are a major challenge to the grape industry worldwide. GTDs are responsible for considerable loss of quality, production, and vineyard longevity. Seventy five percent of Chilean vineyards are estimated to be affected by GTDs. GTDs are complex diseases caused by several species of fungi, including Neofusicoccum parvum, Diplodia seriata, and Phaeomoniella chlamydospora. In this study, we report the isolation of 169 endophytic and 209 epiphytic fungi from grapevines grown under organic and conventional farming in Chile. Multiple isolates of Clonostachys rosea, Trichoderma sp., Purpureocillium lilacium, Epiccocum nigrum, Cladosporium sp., and Chaetomium sp. were evaluated for their potential of biocontrol activity against fungal trunk pathogens. Tests were carried out using two dual-culture-plate methods with multiple media types, including agar containing grapevine wood extract to simulate in planta nutrient conditions. Significant pathogen growth inhibition was observed by all isolates tested. C. rosea showed 98.2% inhibition of all pathogens in presence of grapevine wood extract. We observed 100% pathogen growth inhibition when autoclaved lignified grapevine shoots were pre-inoculated with either C. rosea strains or Trichoderma sp.. Overall these results show that C. rosea strains isolated from grapevines are promising biocontrol agents against GTDs.

microbiology↗

bioRxiv2020

Risk factors associated with mortality in hospitalized patients with SARS-CoV-2 infection. A prospective, longitudinal, unicenter study in Reus, Spain

Spain is one of the countries that has suffered the most from the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the strain that causes coronavirus disease 2019 (COVID-19). However, there is a lack of information on the characteristics of this disease in the Spanish population. The objective of this study has been to characterize our patients from an epidemiological point of view and to identify the risk factors associated with mortality in our geographical area. We performed a prospective, longitudinal study on 188 hospitalized cases of SARS-Cov-2 infection in Hospital Universitari de Sant Joan, in Reus, Spain, admitted between 15th March 2020 and 30th April 2020. We recorded demographic data, signs and symptoms and comorbidities. We also calculated the Charlson and McCabe indices. A total of 43 deaths occurred during the study period. Deceased patients were older than the survivors (77.7 {+/-} 13.1 vs. 62.8 {+/-} 18.4 years; p < 0.001). Logistic regression analyses showed that fever, pneumonia, acute respiratory distress syndrome, diabetes mellitus and cancer were the variables that showed independent and statistically significant associations with mortality. The Charlson index was more efficient than the McCabe index in discriminating between deceased and survivors. This is one of the first studies to describe the factors associated with mortality in patients infected with SARS-CoV-2 in Spain, and one of the few in the Mediterranean area. We identified the main factors independently associated with mortality in our population. Further studies in are needed to complete and confirm our findings.

microbiology↗