TScan-II: A genome-scale platform for the de novo identification of CD4+ T cell epitopes.

CD4+ T cells play fundamental roles in orchestrating immune responses and tissue homeostasis. However, our inability to associate peptide human leukocyte antigen class-II (HLA-II) complexes with their cognate T cell receptors (TCRs) in an unbiased manner has hampered our understanding of CD4+ T cell function and role in pathologies. Here, we introduce TScan-II, a highly sensitive genome-scale CD4+ antigen discovery platform. This platform seamlessly integrates the endogenous HLA-II antigen-processing machinery in synthetic antigen-presenting cells and TCR signaling in T cells, enabling the simultaneous screening of multiple HLAs and TCRs. Leveraging genome-scale human, virome, and epitope mutagenesis libraries, TScan-II facilitates de novo antigen discovery and deep exploration of TCR specificity. We demonstrate TScan-II's potential for basic and translational research by identifying a non-canonical antigen for a cancer-reactive CD4+ T cell clone. Additionally, we identified two antigens for clonally expanded CD4+ T cells in Sjögren's disease, which bind distinct HLAs and are expressed in HLA-II-positive ductal cells within affected salivary glands.

Inhibition of JAK-STAT pathway corrects salivary gland inflammation and interferon driven immune activation in Sjögren's disease.

OBJECTIVES: Inflammatory cytokines that signal through the Janus kinases-signal transducer and activator of transcription (JAK-STAT) pathway, especially interferons (IFNs), are implicated in Sjögren's disease (SjD). Although inhibition of JAKs is effective in other autoimmune diseases, a systematic investigation of IFN-JAK-STAT signalling and the effect of JAK inhibitor (JAKi) therapy in SjD-affected human tissues has not been fully investigated. METHODS: Human minor salivary glands (MSGs) and peripheral blood mononuclear cells (PBMCs) were investigated using bulk or single-cell (sc) RNA sequencing (RNAseq), immunofluorescence (IF) microscopy and flow cytometry. Ex vivo culture assays on PBMCs and primary salivary gland epithelial cell (pSGEC) lines were performed to model changes in target tissues before and after JAKi. RESULTS: RNAseq and IF showed activated JAK-STAT pathway in SjD MSGs. Elevated IFN-stimulated gene (ISGs) expression associated with clinical variables (eg, focus scores, anti-SSA positivity). scRNAseq of MSGs exhibited cell type-specific upregulation of JAK-STAT and ISGs; PBMCs showed similar trends, including markedly upregulated ISGs in monocytes. Ex vivo studies showed elevated basal pSTAT levels in SjD MSGs and PBMCs that were corrected with JAKi. SjD-derived pSGECs exhibited higher basal ISG expressions and exaggerated responses to IFN-ß, which were normalised by JAKi without cytotoxicity. CONCLUSIONS: SjD patients' tissues exhibit increased expression of ISGs and activation of the JAK-STAT pathway in a cell type-dependent manner. JAKi normalises this aberrant signalling at the tissue level and in PBMCs, suggesting a putative viable therapy for SjD, targeting both glandular and extraglandular symptoms. Predicated on these data, a phase Ib/IIa randomised controlled trial to treat SjD with tofacitinib was initiated.

Histopathology and SARS-CoV-2 Cellular Localization in Eye Tissues of COVID-19 Autopsies.

Ophthalmic manifestations and tissue tropism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported in association with coronavirus disease 2019 (COVID-19), but the pathology and cellular localization of SARS-CoV-2 are not well characterized. The objective of this study was to evaluate macroscopic and microscopic changes and investigate cellular localization of SARS-CoV-2 across ocular tissues at autopsy. Ocular tissues were obtained from 25 patients with COVID-19 at autopsy. SARS-CoV-2 nucleocapsid gene RNA was previously quantified by droplet digital PCR from one eye. Herein, contralateral eyes from 21 patients were fixed in formalin and subject to histopathologic examination. Sections of the droplet digital PCR-positive eyes from four other patients were evaluated by in situ hybridization to determine the cellular localization of SARS-CoV-2 spike gene RNA. Histopathologic abnormalities, including cytoid bodies, vascular changes, and retinal edema, with minimal or no inflammation in ocular tissues were observed in all 21 cases evaluated. In situ hybridization localized SARS-CoV-2 RNA to neuronal cells of the retinal inner and outer layers, ganglion cells, corneal epithelia, scleral fibroblasts, and oligodendrocytes of the optic nerve. In conclusion, a range of common histopathologic alterations were identified within ocular tissue, and SARS-CoV-2 RNA was localized to multiple cell types. Further studies will be required to determine whether the alterations observed were caused by SARS-CoV-2 infection, the host immune response, and/or preexisting comorbidities.

Safety and adverse events of EUS-guided gallbladder drainage using lumen-apposing metal stents and percutaneous cholecystostomy tubes: a systematic review and meta-analysis.

BACKGROUND AND AIMS: EUS-guided gallbladder drainage using lumen-apposing metal stents (EUS-GBD-LAMSs) and percutaneous cholecystostomy for gallbladder drainage (PTGBD) are the alternative treatment modalities in high-risk surgical patients with acute cholecystitis (AC). The aim of this study was to compare the safety of these procedures for AC in surgically suboptimal candidates. METHODS: Six studies compared the 2 groups' early, delayed, and overall adverse events; they also compared length of hospital stay, re-interventions, and re-admissions rate. A random effect model calculated odds ratios (ORs) with a 95% confidence interval (CI). RESULTS: The 2 groups had similar early adverse events; however, EUS-GBD-LAMS was associated with a lower rate of delayed (OR, .21; 95% CI, .07-.61; P ≤ .01) and overall (OR, .43; 95% CI, .30-.61; P ≤ .01) adverse events. Patients with EUS-GBD-LAMSs had a shorter hospital stay than PTGBD. CONCLUSIONS: EUS-GBD-LAMS is a safer option than PTGBD and is associated with a shorter hospital stay in nonsurgical candidates with AC.

Clinical analysis of the tooth-implant papilla for two narrow-diameter titanium-zirconium implants in the anterior area: prospective controlled clinical study.

BACKGROUND: Rehabilitation of the anterior area when the mesio-distal space is reduced is a challenge for the clinician, due to the patient's anatomical limitations and aesthetic requirements. Narrow Diameter Implants (NDI) are an option of treatment when the standard diameter implant is not possible, but the evidence is scarce. This prospective clinical study aims to analyze the formation of the tooth-implant papilla between the implant and the adjacent natural tooth in the maxillary lateral incisors and mandibular incisors. METHODS: A total of 40 patients treated with NDI, of titanium-zirconium (Ti-Zr) alloy i.e., 2.9 mm Test Group (TG) and 3.3 mm Control Group (CG), were included. The mesiodistal distance between the adjacent natural teeth was used for implant selection, maintaining 1.5 mm between the fixation and the adjacent tooth. Clinical assessment was performed by a clinical examiner at 6 and 12 months after the final prosthesis. The primary variable was the Jemt Papillary Index. Also, implant survival rate (SR), complications, Implant Stability Quotient (ISQ), and patient-reported outcomes measures (PROMs) such as aesthetics, chewing, phonation, comfort, and self-esteem were analyzed. RESULTS: A significant amount of papilla filling was observed concerning the baseline, with a trend towards more formation of the papilla in the TG, with a JPI score of 3. No significant differences were observed between the two groups regarding implant SR, clinical parameters, and complications. In terms of PROMs, a higher satisfaction in the TG was observed, with significant intergroup differences for aesthetics, comfort, self-esteem, and primary stability ISQ (TG: 59.05 (SD: 5.4) vs. CG: 51.55 (SD: 5.7)). CONCLUSIONS: The 2.9 mm diameter Ti-Zr implants achieved a formation of papilla similar to 3.3 mm implants in the anterior region at 12 months of follow-up after the final prosthetic restoration. The use of Ti-Zr implants with a diameter of 2.9 mm to rehabilitate single teeth in areas of the anterior region, where the mesiodistal distance is limited, showed favorable clinical results and a high degree of satisfaction during 1 year of observation similar to 3.3 mm dental implants. TRIAL REGISTRATION: This study was retrospectively registered in ClinicalTrials.gov with the number NCT05642520, dated 18/11/2022.

Structural and functional analysis of salivary intercalated duct cells reveals a secretory phenotype.

Currently, all salivary ducts (intercalated, striated and collecting) are assumed to function broadly in a similar manner, reclaiming ions that were secreted by the secretory acinar cells while preserving fluid volume and delivering saliva to the oral cavity. Nevertheless, there has been minimal investigation into the structural and functional differences between distinct types of salivary duct cells. Therefore, in this study, the expression profile of proteins involved in stimulus-secretion coupling, as well as the function of the intercalated duct (ID) and striated duct cells, was examined. Particular focus was placed on defining differences between distinct duct cell populations. To accomplish this, immunohistochemistry and in situ hybridization were utilized to examine the localization and expression of proteins involved in reabsorption and secretion of ions and fluid. Further, in vivo calcium imaging was employed to investigate cellular function. Based on the protein expression profile and functional data, marked differences between the IDs and striated ducts were observed. Specifically, the ID cells express proteins native to the secretory acinar cells while lacking proteins specifically expressed in the striated ducts. Further, the ID and striated duct cells display different calcium signalling characteristics, with the IDs responding to a neural stimulus in a manner similar to the acinar cells. Overall, our data suggest that the IDs have a distinct role in the secretory process, separate from the reabsorptive striated ducts. Instead, based on our evidence, the IDs express proteins found in secretory cells, generate calcium signals in a manner similar to acinar cells, and, therefore, are likely secretory cells. KEY POINTS: Current studies examining salivary intercalated duct cells are limited, with minimal documentation of the ion transport machinery and the overall role of the cells in fluid generation. Salivary intercalated duct cells are presumed to function in the same manner as other duct cells, reclaiming ions, maintaining fluid volume and delivering the final saliva to the oral cavity. Here we systematically examine the structure and function of the salivary intercalated duct cells using immunohistochemistry, in situ hybridization and by monitoring in vivo Ca2+ dynamics. Structural data revealed that the intercalated duct cells lack proteins vital for reabsorption and express proteins necessary for secretion. Ca2+ dynamics in the intercalated duct cells were consistent with those observed in secretory cells and resulted from GPCR-mediated IP3 production.

Association of G protein-coupled receptor 78 with salivary dysfunction in male Sjögren's patients.

OBJECTIVE: Sjögren's disease (SjD) has a strong sex bias, suggesting an association with sex hormones. Male SjD represents a distinct subset of the disease, but the pathogenic mechanisms of male SjD is poorly characterized. The aim of this study is to identify initiating events related to the development of gland hypofunction and autoimmunity in male SjD patients. MATERIALS AND METHODS: Human minor salivary glands were transcriptomically analyzed with microarrays to detect differentially expressed genes in male SjD patients. Identified genes were tested on their involvement in the disease using conditional transgenic mice and gene-overexpressing cells. RESULTS: GPR78, an orphan G protein-coupled receptor, was overexpressed in the salivary glands of male SjD patients compared with male healthy controls and female SjD patients. Male GPR78 transgenic mice developed salivary gland hypofunction with increased epithelial apoptosis, which was not seen in control or female transgenic mice. In cell culture, GPR78 overexpression decreased lysosomal integrity, leading to caspase-dependent apoptotic cell death. GPR78-induced cell death in vitro was inhibited by treatment with estradiol. CONCLUSION: GPR78 overexpression can induce apoptosis and salivary gland hypofunction in male mice through lysosomal dysfunction and increased caspase-dependent apoptosis in salivary gland epithelium, which may drive disease in humans.

Days spent on non-invasive ventilation support: can it determine when to initiate VV- ECMO? Observational study in a cohort of Covid-19 patients.

BACKGROUND: The study evaluates the impact of the time between commencing non-invasive ventilation (NIV) support and initiation of venovenous extracorporeal membrane oxygenation (VV-ECMO) in a cohort of critically ill patients with coronavirus disease 2019 (COVID-19) associated acute respiratory distress syndrome (ARDS). METHODS: Prospective observational study design in an intensive Care Unit (ICU) of a tertiary hospital in Barcelona (Spain). All patients requiring VV-ECMO support due to COVID-19 associated ARDS between March 2020 and January 2022 were analysed. Survival outcome was determined at 90 days after VV-ECMO initiation. Demographic data, comorbidities at ICU admission, RESP (respiratory ECMO survival prediction) score, antiviral and immunomodulatory treatments received, inflammatory biomarkers, the need for vasopressors, the thromboprophylaxis regimen received, and respiratory parameters including the length of intubation previous to ECMO and the length of each NIV support (high-flow nasal cannula, continuous positive airway pressure and bi-level positive airway pressure), were also collated in order to assess risk factors for day-90 mortality. The effect of the time lapse between NIV support and VV-ECMO on survival was evaluated using logistic regression and adjusting the association with all factors that were significant in the univariate analysis. RESULTS: Seventy-two patients finally received VV-ECMO support. At 90 days after commencing VV-ECMO 35 patients (48%) had died and 37 patients (52%) were alive. Multivariable analysis showed that at VV-ECMO initiation, age (p = 0.02), lactate (p = 0.001), and days from initiation of NIV support to starting VV-ECMO (p = 0.04) were all associated with day-90 mortality. CONCLUSIONS: In our small cohort of VV-ECMO patients with COVID-19 associated ARDS, the time spent between initiation of NIV support and VV-ECMO (together with age and lactate) appeared to be a better predictor of mortality than the time between intubation and VV-ECMO.

Drug Repurposing to Inhibit Histamine N-Methyl Transferase.

Lower activity of the histaminergic system is associated with neurological disorders, including Alzheimer's disease (AD). Thus, the enhancement of histaminergic neurotransmission by inhibition of histamine N-methyl transferase (HNMT), which degrades histamine, appears as an important approach. For this purpose, rigid and flexible molecular docking studies of 185 FDA-approved drugs with the HNMT enzyme were carried out to select two compounds to perform molecular dynamics (MD) simulations to evaluate the binding free energies and stability of the enzyme-drug complexes. Finally, an HNMT inhibition assay was performed to corroborate their effect towards HNMT. Molecular docking studies with HNMT allowed the selection of dihydroergotamine and vilazodone since these molecules showed the lowest Gibbs free energy values. Analysis of the binding mode of vilazodone showed interactions with the binding pocket of HNMT with Glu28, Gln143, and Asn283. In contrast, dihydroergotamine binds to the HNMT active site in a different location, apparently because it is overall the more rigid ligand compared to flexible vilazodone. HNMT inhibitory activity for dihydroergotamine and vilazodone was corroborated (IC50 = 72.89 µM and 45.01 µM, respectively) by in vitro assays. Drug repurposing of HNMT was achieved by employing computational studies.

Risk factors and incidence of cytomegalovirus viremia and disease in pediatric patients with allogeneic hematopoietic stem cell transplantation: An 8-year single-center experience in Latin America.

BACKGROUND: Cytomegalovirus infection represents a significant cause of morbidity and mortality after hematopoietic stem cell transplantation. This study aimed to evaluate the incidence of viremia and disease due to cytomegalovirus and the risk factors in pediatric patients with hematopoietic stem cell transplantation in our institution. METHODS: This was a retrospective cohort of patients under 19 years of age who underwent allogeneic hematopoietic stem cell transplantation due to any indication between 2012 and 2019. The analysis included the diagnosis of cytomegalovirus viremia or disease during post-transplant follow-up, evaluation of risk factors, and outcomes. The statistical analysis included univariate and multivariate analyses, and the cumulative incidence of cytomegalovirus viremia was determined by the Kaplan-Meier method using STATA 14 statistical software. RESULTS: A total of 182 transplants were included. At 100 days, the cumulative incidence of cytomegalovirus viremia was 70.5%, and that of cytomegalovirus disease was 4.7%. Overall survival at 2 years was 74%, and event-free survival was 64%. The remaining demographic characteristics were not predictors of infection. There was no association between viremia and relapse or survival of the patients. Higher mortality was noted in cytomegalovirus disease. CONCLUSIONS: During the study period, the incidence of cytomegalovirus disease was similar to that of other pediatric reports, but the incidence of viremia was higher. Pre-emptive therapy has diminished disease rates and death due to infection. Viral load cutoff points should be standardized to guide treatment and avoid myelotoxicity.

Demographic and clinical characterization of pediatric group patients with inborn errors of the immune system in a Colombian tertiary hospital.

INTRODUCTION: In recent decades, there has been a growing increase in the diagnosis of patients with inborn errors of the immune system, formerly known as primary immunodeficiency disorders (PIDs). Timely diagnosis remains a challenge due to low clinical suspicion and poor education on the subject. It is estimated that between 70% and 90% of these pathologies remain underdiagnosed in our environment. OBJECTIVE: The objective of this study is to characterize the demographic and clinical presentation of pediatric group patients with inborn errors of the immune system in a Colombian tertiary hospital. METHODS: Retrospective descriptive study of 306 patients with a diagnosis of innate errors of the immune system who consulted the PID clinic between 2011 and 2018 in a high-complexity institution in Cali, Colombia. RESULTS: Three-hundred and six patients were included. The median age was 4 years (IQR 2.3-7.7 years), and 59.5% of the patients were male. According to the International Union of Immunological Societies Expert Committee for Primary Immunodeficiency classification for inborn errors of the immune system, the most common group was antibody deficiency in 74.8% (n˂229), especially in the age group between 1 and 5 years. The least frequent in our population was complement deficiency. Of the warning signs stipulated for these pathologies, the most frequent were the (1) need for intravenous antibiotics (32%), (2) difficulty growing (15.7%), (3) four or more episodes of ear infection (10.8%), and (4) abscesses in organs or cutaneous abscesses (12.7%). No patient reported two or more episodes of pneumonia or sinusitis, and only 5.8% of the patients received a bone marrow transplant. CONCLUSIONS: Innate errors of the immune system require an early diagnosis with follow-up from an early age to ensure adequate management and follow-up in order to reduce morbidity and mortality. It is imperative to sensitize the medical population about the existence of these pathologies so that early intervention can be carried out, which improves the quality of life of patients and their families.

[Deliberative dialogue with Ibero-American universities on interventions in student mental health during the COVID-19 pandemicDiálogo deliberativo com universidades ibero-americanas sobre intervenções em saúde mental dos estudantes na pandemia de COVID-19]. / Diálogo deliberativo con universidades iberoamericanas sobre intervenciones en salud mental estudiantil durante la pandemia de COVID-19.

Objective: To contextualize a synthesis of evidence on interventions in student mental health during the COVID-19 pandemic through a deliberative dialogue with Ibero-American universities. Methods: An evidence synthesis and synchronous dialogues were previously conducted, consisting of subgroup discussions about the design and implementation of mental health interventions. An analysis of dialogic data was conducted, then organized by topic. Results: Fifty-seven representatives of 17 public and private Ibero-American universities participated in the meeting. In terms of the design of interventions, mental health is perceived as neglected, although its profile was raised by the pandemic. Interventions are guided by detection of needs; scientific evidence is rarely used to design them. Importance was given to forming an interdisciplinary team with continuous training in order to design a specific program that also covers families and teaching/administrative staff. In terms of implementation, problems include saturation of services due to high demand and lack of basic resources among students. Regarding the provision of resources, the influence of the broader context, including the institutional context, is undeniable. The dialogues were perceived as an opportunity to build a new set of interventions. Conclusions: These dialogues enriched the description of interventions already described in the literature on student mental health during the COVID-19 pandemic. However, implementing such interventions in the region means addressing previous neglect and a high level of unmet basic needs.

Objetivo: Contextualizar uma síntese de evidências sobre intervenções em saúde mental de estudantes universitários na pandemia de COVID-19, por meio do diálogo deliberativo com universidades ibero-americanas. Métodos: A partir de uma síntese de evidências previamente elaborada, o diálogo síncrono foi conduzido por meio de discussões em subgrupos sobre o planejamento e a implementação de intervenções em saúde mental. Os dados obtidos foram analisados e resumidos por área temática. Resultados: Cinquenta e sete integrantes de 17 universidades ibero-americanas públicas e privadas participaram do encontro. Os participantes indicaram que a saúde mental é negligenciada no planejamento das intervenções, mas ganhou visibilidade na pandemia. As intervenções são direcionadas às necessidades identificadas e raramente planejadas com base em evidências científicas. Disseram considerar importante formar uma equipe interdisciplinar com capacitação contínua para planejar um programa específico que englobe também familiares e o corpo docente e administrativo. Implementar intervenções é complicado porque os serviços estão sobrecarregados devido à grande demanda e à falta de recursos básicos para os estudantes. O contexto macro e institucional claramente influencia a disponibilização de recursos. O diálogo foi visto como uma oportunidade para consolidar um novo conjunto de intervenções. Conclusões: O presente diálogo contribuiu para enriquecer a literatura de intervenções de saúde mental para estudantes universitários na pandemia de COVID-19. Implementar intervenções no nosso contexto requer sanar as falhas por negligência passada e as enormes necessidades básicas não atendidas.

Lysosome-associated membrane protein 3 misexpression in salivary glands induces a Sjögren's syndrome-like phenotype in mice.

OBJECTIVES: Sjögren's syndrome (SS) is an autoimmune sialadenitis with unknown aetiology. Although extensive research implicated an abnormal immune response associated with lymphocytes, an initiating event mediated by salivary gland epithelial cell (SGEC) abnormalities causing activation is poorly characterised. Transcriptome studies have suggested alternations in lysosomal function are associated with SS, but a cause and effect linkage has not been established. In this study, we demonstrated that altered lysosome activity in SGECs by expression of lysosome-associated membrane protein 3 (LAMP3) can initiate an autoimmune response with autoantibody production and salivary dysfunction similar to SS. METHODS: Retroductal cannulation of the submandibular salivary glands with an adeno-associated virus serotype 2 vector encoding LAMP3 was used to establish a model system. Pilocarpine-stimulated salivary flow and the presence of autoantibodies were assessed at several time points post-cannulation. Salivary glands from the mice were evaluated using RNAseq and histologically. RESULTS: Following LAMP3 expression, saliva flow was significantly decreased and serum anti-Ro/SSA and La/SSB antibodies could be detected in the treated mice. Mechanistically, LAMP3 expression increased apoptosis in SGECs and decreased protein expression related to saliva secretion. Analysis of RNAseq data suggested altered lysosomal function in the transduced SGECs, and that the cellular changes can chemoattract immune cells into the salivary glands. Immune cells were activated via toll-like receptors by damage-associated molecular patterns released from LAMP3-expressing SGECs. CONCLUSIONS: These results show a critical role for lysosomal trafficking in the development of SS and establish a causal relationship between LAMP3 misexpression and the development of SS.

Successful engraftment of haploidentical stem cell transplant with post-transplantation cyclophosphamide in a patient with adenosine deaminase deficiency.

BACKGROUND: SCID are characterized by an imbalance in cellular and humoral immunity. Enzyme ADA deficiency represents from 10% to 15% of the SCID. This generates diminished maturation of the cell precursors. Treatments include enzyme replacement therapy, allogenic, or autologous HSCT with gene therapy, with HSCT being of choice when an identical HLA donor exists. CASE REPORT: Male patient, without relevant family antecedents or consanguinity. The patient had multiple infections during the first months of life, evidencing low immunoglobulin levels, with absence of T and B lymphocytes, and natural killer cells. Severe combined immunodeficiencies are considered due to ADA deficiency; management was begun and is derived to our hospital. Admission at 8 months of life, with chronic malnutrition and psychomotor retardation. The HLA studies were conducted without finding an identical donor, taken to HSCT with haploidentical donor. Conditioning regimen with cyclophosphamide, fludarabine, melphalan, and thymoglobulin. This patient received prophylaxis for graft-versus-host disease with cyclophosphamide, cyclosporine, and methotrexate. A 22 months post-transplant, the patient was without immunosuppressants or immunoglobulin, without evidence of graft-versus-host disease or new infections. CONCLUSIONS: The ADA deficiency is an infrequent pathology that can be potentially fatal if adequate treatment is not started. Haploidentical HSCT, using post-transplantation cyclophosphamide, emerges as a viable option with which good results can be achieved and improve the quality of life in patients with no other therapeutic alternatives.

Pediatric hemophagocytic lymphohistiocytosis: A rarely diagnosed entity in a developing country.

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is an exaggerated inflammatory reaction secondary to a host's inadequate immune response causing a self-perpetuating loop of altered regulation. Signs and symptoms of HLH are compatible with other common diseases and are nonspecific. Underdiagnosis makes it difficult to estimate the real incidence of HLH, especially in developing countries. METHODS: Retrospective, descriptive study of pediatric patients admitted to a high-complexity institution in Cali, Colombia between 2012 and 2019 with HLH diagnosis. Medical history review to complete an electronic database and a secondary, descriptive analysis was carried out. The study was approved by the Institutional Ethics Committee. RESULTS: Twenty-one patients were included. 52.4 % of the population was male with a median age of 9.3 years [IQR (3.0-13.7 years)]. More than half of patients (66.6 %) had viral disease at diagnosis, the most frequent being Epstein-Barr Virus (EBV) (52.3 %) and dengue (14.3 %). Three patients had confirmed gene mutations (G6PC3, XIAP, and UNC13D). 95 % of the patients were treated with the HLH 2004 protocol, half of them received incomplete protocol with intravenous immunoglobulin (IVIG) and/or systemic steroids, while the other half received the complete protocol including etoposide and cyclosporine. More than three-fourths (76.2 %) required admission to an ICU with a median stay of 14 days [IQR (11-37 days)] and a median hospital stay of 30 days [IQR (18-93 days)]. 14.3 % (n = 3) of patients died. CONCLUSIONS: HLH is a complex disease that requires multidisciplinary management with secondary HLH due to EBV infection being a common cause. There is increasing awareness of HLH diagnosis in developing countries such as Colombia which can offer earlier treatment options and better outcomes.

Hematopoietic Stem Cell Transplantation in Children with Inborn Errors of Immunity: a Multi-center Experience in Colombia.

PURPOSE: To characterize the pediatric population with inborn errors of immunity (IEI) that was treated with hematopoietic stem cell transplantation (HSCT) in three reference centers in Colombia. What have been the characteristics and outcomes of hematopoietic stem cell transplantation in pediatric patients with inborn errors of immunity in three reference care centers in Colombia between 2007 and 2018? METHODS: We conducted an observational, retrospective cohort study in children with a diagnosis of IEI who underwent HSCT between 2007 and 2018. RESULTS: Forty-seven patients were identified, and 5 were re-transplanted. Sixty-eight percent were male. The median age at diagnosis was 0.6 years, and for HSCT was 1.4 years. The most common diseases were chronic granulomatous disease (38%) followed by severe combined immune deficiencies (19%) and hemophagocytic lymphohistiocytosis (15%). Cord blood donors were the most used source of HSCT (44%). T cell-replete grafts from haploidentical donors using post-transplantation cyclophosphamide represent 37% of the cohort. All patients received conditioning, 62% with a non-myeloablative regimen. Calcineurin inhibitors were the main graft-versus-host disease prophylaxis (63.8%). Acute graft-versus-host disease developed in 35% of the total patients. The most frequent post-transplant infections were viral and fungal infections. The 1-year overall survival rates for the patients who received HSCT from identical, haploidentical, and cord sources were 80%, 72%, and 63%, respectively. The 5-year overall survival was 63%. CONCLUSIONS: HSCT is a curative treatment option for some IEI and can be performed with any donor type. Early and timely treatment in referral centers can improve survival.

Synaptotagmin-1 overexpression under inflammatory conditions affects secretion in salivary glands from Sjögren's syndrome patients.

Sjögren's syndrome (SS) is an autoimmune exocrinopathy associated with severe secretory alterations by disruption of the glandular architecture integrity, which is fundamental for a correct function and localization of the secretory machinery. Syt-1, PI(4,5)P2 and Ca2+ are significant factors controlling exocytosis in different secretory cells, the Ca2+ role being the most studied. Salivary acinar cells from SS-patients show a defective agonist-regulated intracellular Ca2+ release together with a decreased IP3R expression level, and this condition may explain a reduced water release. However, there are not reports where Syt-1, PI(4,5)P2 and Ca2+ in acinar cells of SS patients had been studied. In the present study, we analyzed the expression and/or localization of Syt-1 and PI(4,5)P2 in acinar cells of labial salivary gland biopsies from SS-patients and control individuals. Also, we evaluated whether the overexpression of Syt-1 and the loss of cell polarity induced by TNF-α or loss of interaction between acinar cell and basal lamina, alters directionality of the exocytosis process, Ca2+ signaling and α-amylase secretion in a 3D-acini model stimulated with cholinergic or ß-adrenergic agonists. In addition, the correlation between Syt-1 protein levels and clinical parameters was evaluated. The results showed an increase of Syt-1 mRNA and protein levels, and a high number of co-localization points of Syt-1/STX4 and PI(4,5)P2/Ezrin in the acinar basolateral region of LSG from SS-patients. With regard to 3D-acini, Syt-1 overexpression increased exocytosis in the apical pole compared to control acini. TNF-α stimulation increased exocytic events in the basal pole, which was further enhanced by Syt-1 overexpression. Additionally, altered acinar cell polarity affected Ca2+ signaling and amylase secretion. Overexpression of Syt-1 was associated with salivary gland alterations revealing that the secretory dysfunction in SS-patients is linked to altered expression and/or localization of secretory machinery components together with impaired epithelial cell polarity. These findings provide a novel insight on the pathological mechanism implicated in ectopic secretory products to the extracellular matrix of LSG from SS-patients, which might initiate inflammation.

Amino Acid-Derived Sensors for Specific Zn2+ Detection Using Hyperpolarized 13 C Magnetic Resonance Spectroscopy.

Alterations in Zn2+ concentration are seen in normal tissues and in disease states, and for this reason imaging of Zn2+ is an area of active investigation. Herein, enriched [1-13 C]cysteine and [1-13 C2 ]iminodiacetic acid were developed as Zn2+ -specific imaging probes using hyperpolarized 13 C magnetic resonance spectroscopy. [1-13 C]cysteine was used to accurately quantify Zn2+ in complex biological mixtures. These sensors can be employed to detect Zn2+ via imaging mechanisms including changes in 13 C chemical shift, resonance linewidth, or T1 .

Unique association of hypochondroplasia with craniosynostosis and cleft palate in a Mexican family.

Hypochondroplasia (HCH) is a skeletal dysplasia caused by an abnormal function of the fibroblast growth factor receptor 3. Although believed to be relatively common, its prevalence and phenotype are not well established owing to its clinical, radiological, and genetic heterogeneity. Here we report on a molecularly proven HCH family with an affected father and two children. The siblings (male and female) with HCH also had craniosynostosis and cleft palate, respectively. The present report supports the conclusion that the full clinical spectrum of HCH is not completely delineated. It also suggests that secondary, as yet unknown, modifying factors can influence the final phenotype.

Hepatitis A, cardiomyopathy, aplastic anemia, and acute liver failure: A devastating scenario.

Hepatitis A virus (HAV) causes an acute infection and is usually asymptomatic in children. When clinical manifestations appear, these include choluria, jaundice, and abdominal pain. Although infrequent, extra-hepatic manifestations related to HAV have been described, affecting the heart, bone marrow, blood vessels, and other tissues.A 10-year-old boy from a rural area presented with a 15-day history of malaise, fever, and jaundice; laboratory examinations were compatible with HAV infection. The patient turned encephalopathic and was remitted to our center, where laboratory examinations showed a medullary aplasia and fulminant hepatitis requiring a liver transplant that was performed 72 hours after admission. At 24 hours post transplant, the patient developed a cardiomyopathy secondary to HAV, and intravenous immunoglobulin was administered. The patient is still alive and attending his medical check-ups.Although rare, extra-hepatic manifestations of HAV infection have been described in 14% of cases. The groups of patients affected are usually aged and present with high bilirubin levels. Acquired aplastic anemia and myocarditis caused by HAV are uncommon, and its pathophysiology has not yet been elucidated.HAV infection is usually asymptomatic in children, although extra-hepatic manifestations can appear requiring early detection and management.