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Prolonged recovery is common after acute SARS-CoV-2 infection; however, the pathophysiological mechanisms underpinning Long COVID syndrome remain unknown. VWF/ADAMTS-13 imbalance, dysregulated angiogenesis, and immunothrombosis are hallmarks of acute COVID-19. We hypothesized that VWF/ADAMTS-13 imbalance persists in convalescence together with endothelial cell (EC) activation and angiogenic disturbance. Additionally, we postulate that ongoing immune cell dysfunction may be linked to sustained EC and coagulation activation.Fifty patients were reviewed at a minimum of 6 weeks following acute COVID-19. ADAMTS-13, Weibel Palade Body (WPB) proteins, and angiogenesis-related proteins were assessed and clinical evaluation and immunophenotyping performed. Comparisons were made with healthy controls (n = 20) and acute COVID-19 patients (n = 36).ADAMTS-13 levels were reduced (p = 0.009) and the VWF-ADAMTS-13 ratio was increased in convalescence (p = 0.0004). Levels of platelet factor 4 (PF4), a putative protector of VWF, were also elevated (p = 0.0001). A non-significant increase in WPB proteins Angiopoietin-2 (Ang-2) and Osteoprotegerin (OPG) was observed in convalescent patients and WPB markers correlated with EC parameters. Enhanced expression of 21 angiogenesis-related proteins was observed in convalescent COVID-19. Finally, immunophenotyping revealed significantly elevated intermediate monocytes and activated CD4+ and CD8+ T cells in convalescence, which correlated with thrombin generation and endotheliopathy markers, respectively.Our data provide insights into sustained EC activation, dysregulated angiogenesis, and VWF/ADAMTS-13 axis imbalance in convalescent COVID-19. In keeping with the pivotal role of immunothrombosis in acute COVID-19, our findings support the hypothesis that abnormal T cell and monocyte populations may be important in the context of persistent EC activation and hemostatic dysfunction during convalescence.

Objective The disease-modifying therapies (DMT), dimethyl fumarate (DMF) and fingolimod (FTY) improve the outcomes in multiple sclerosis (MS) by reducing relapses and numbers and volume of lesions. They mediate their effects through reduction of immune reactivation, which may potentially lead to lymphopaenia and increased risk of infections. Previous studies have examined the effects of these therapies on lymphocyte subsets; however, the in vivo effects on circulating lymphocyte proliferation require further elucidation. The aim of this study was to determine the effects of DMF and FTY on T-cell proliferation in patients with MS. Method We examined T-cell lymphocyte proliferation and lymphocyte subsets in ten patients (five on DMF, five on FTY) before starting DMT and again 4 to 11 months after being maintained on DMT. Results In the FTY-treated group, the mean percentage proliferation was significantly lower using both assays (PHA assay mean percentage change − 51.2 ± 25.97, p p p = 0.316; anti-CD3/CD28, p = 0.373). Conclusions This pilot study suggests that the T-lymphocytes of patients on FTY have an abnormal proliferation response as well as being reduced in the circulation.

Background Up to 70% of patients with ANCA-associated vasculitis (AAV) develop GN, with 26% progressing to ESKD. Diagnostic-grade and noninvasive tools to detect active renal inflammation are needed. Urinary soluble CD163 (usCD163) is a promising biomarker of active renal vasculitis, but a diagnostic-grade assay, assessment of its utility in prospective diagnosis of renal vasculitis flares, and evaluation of its utility in proteinuric states are needed. Methods We assessed a diagnostic-grade usCD163 assay in (1) a real-world cohort of 405 patients with AAV and 121 healthy and 488 non-AAV disease controls; (2) a prospective multicenter study of 84 patients with potential renal vasculitis flare; (3) a longitudinal multicenter cohort of 65 patients with podocytopathy; and (4) a cohort of 29 patients with AAV (with or without proteinuria) and ten controls. Results We established a diagnostic reference range, with a cutoff of 250 ng/mmol for active renal vasculitis (area under the curve [AUC], 0.978). Using this cutoff, usCD163 was elevated in renal vasculitis flare (AUC, 0.95) but remained low in flare mimics, such as nonvasculitic AKI. usCD163's specificity declined in patients with AAV who had nephrotic-range proteinuria and in those with primary podocytopathy, with 62% of patients with nephrotic syndrome displaying a "positive" usCD163. In patients with AAV and significant proteinuria, usCD163 normalization to total urine protein rather than creatinine provided the greatest clinical utility for diagnosing active renal vasculitis. Conclusions usCD163 is elevated in renal vasculitis flare and remains low in flare mimics. Nonspecific protein leakage in nephrotic syndrome elevates usCD163 in the absence of glomerular macrophage infiltration, resulting in false-positive results; this can be corrected with urine protein normalization.

BackgroundThe PRECISE Study, a multi-phase cross-sectional seroprevalence study of anti-SARS-CoV-2 antibodies in Irish healthcare workers (HCW) investigated: (1) risk factors for SARS-CoV-2 seropositivity, (2) the durability of antibody responses in a highly vaccinated HCW cohort, and (3) the neutralisation capacity of detected antibodies, prior to booster COVID-19 vaccination.Materials and methodsSerology samples were collected across two hospital sites in November 2021 and analysed using the Roche Elecsys Anti-SARS-CoV-2/Elecsys-S Anti-SARS-CoV-2 assays to detect anti-nucleocapsid (N) and anti-spike (S) antibodies respectively. Paired serology results from prior study phases were used to analyse changes in individual HCW serostatus over time. Risk-factors for SARS-CoV-2 infection were assessed for demographic and work-related factors. Antibody neutralisation capacity was assessed in a subset of samples via an in vitro ACE2 binding enzyme-linked immunosorbent assay.Results2,344 HCW samples were analysed. Median age was 43 years (IQR 33–50) with 80.5% (n = 1,886) female participants. Irish (78.9%, n = 1,850) and Asian (12.3%, n = 288) were the most commonly reported ethnicities. Nursing/midwifery (39.3%, n = 922) was the most common job role. 97.7% of participants were fully vaccinated, with Pfizer (81.1%, n = 1,902) and AstraZeneca (16.1%, n = 377) the most common vaccines received. Seroprevalence for anti-SARS-CoV-2 antibodies indicating prior infection was 23.4%, of these 33.6% represented previously undiagnosed infections. All vaccinated participants demonstrated positive anti-S antibodies and in those with paired serology, no individual demonstrated loss of previously positive anti-S status below assay threshold for positivity. Interval loss of anti-N antibody positivity was demonstrated in 8.8% of previously positive participants with paired results. Risk factors for SARS-CoV-2 seropositivity suggestive of previous infection included age 18–29 years (aRR 1.50, 95% CI 1.19–1.90, p < 0.001), India as country of birth (aRR 1.35, 95% CI 1.01–1.73, p = 0.036), lower education level (aRR 1.35, 95% CI 1.11–1.66, p = 0.004) and HCA job role (aRR 2.12, 95% CI 1.51–2.95, p < 0.001). Antibody neutralisation varied significantly by anti-SARS-CoV-2 antibody status, with highest levels noted in those anti-N positive, in particular those with vaccination plus previous SARS-CoV-2 infection.ConclusionAll vaccinated HCWs maintained anti-S positivity prior to COVID-19 booster vaccination, however anti-N positivity was more dynamic over time. Antibody neutralisation capacity was highest in participants with COVID-19 vaccination plus prior SARS-CoV-2 infection.

Introduction Serological SARS-CoV-2 assays have an important role in guiding the pandemic response. This research aimed to compare the performance of 2 antinucleocapsid assays. Methods Serum from 49 HCWs was analysed at baseline and 6 months using the Abbott diagnostics SARS-CoV-2 IgG assay and the Roche Diagnostics Elecsys Anti-SARS-CoV-2 total antibody assay. Results At baseline, 14/49 participants (29%) demonstrated antibody reactivity using the Abbott assay. At 6 months, 4/14 participants (29%) continued to demonstrate reactivity. A total of 14/49 (29%) participants had detectable antibodies at baseline using the Roche assay. In total, 13/14 (93%) of participants demonstrated antibody reactivity at 6 months. The Abbott assay showed a statistically significant difference in the signal-to-threshold values of baseline reactive samples when repeated at 6 months (p = 0.001). This was not seen with the Roche assay (p = 0.51). Conclusion In this small study, the Roche Diagnostics Elecsys Anti-SARS-CoV-2 total antibody assay appears superior in performance to the Abbott diagnostics SARS-CoV-2 IgG assay in accurately detecting participants with a history of confirmed COVID-19 disease at 6 months follow-up. This finding should be born in mind in the planning of future seroprevalence studies, especially when considering the use of anti-nucleocapsid assays.

Rationale: Much is known about the acute infective process of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative virus of the coronavirus disease (COVID-19) pandemic. The marked inflammatory response and coagulopathic state in acute SARS-CoV-2 infection may promote pulmonary fibrosis. However, little is known about the incidence and seriousness of post–COVID-19 pulmonary pathology. Objectives: To describe the respiratory recovery and self-reported health after infection at the time of outpatient attendance. Methods: Infection severity was graded into three groups: 1) not requiring admission, 2) requiring hospital admission, and 3) requiring intensive care unit care. Participants underwent chest radiography and a 6-minute walk test (6MWT). Fatigue and subjective return to health were assessed, and concentrations of CRP (C-reactive protein), IL-6 (interleukin-6), sCD25 (soluble CD25), and D-dimer were measured. The associations between initial illness and abnormal chest X-ray findings, 6MWT distance, and perception of maximal exertion were investigated. Results: A total of 487 patients were offered an outpatient appointment, of whom 153 (31%) attended for assessment at a median of 75 days after diagnosis. A total of 74 (48%) had required hospital admission during acute infection. Persistently abnormal chest X-ray findings were seen in 4%. The median 6MWT distance covered was 460 m. A reduced distance covered was associated with frailty and length of inpatient stay. A total of 95 (62%) patients believed that they had not returned to full health, whereas 47% met the case definition for fatigue. Ongoing ill health and fatigue were associated with an increased perception of exertion. None of the measures of persistent respiratory disease were associated with initial disease severity. Conclusions: This study highlights the rates of objective respiratory disease and subjective respiratory symptoms after COVID-19 and the complex multifactorial nature of post–COVID-19 ill health.

N-methyl-d-aspartate receptor antibody (NMDAR-Ab) encephalitis consensus criteria has recently been defined. We aimed to examine the prevalence of NMDAR-Ab encephalitis in patients with first episode psychosis (FEP) and treatment resistant schizophrenia (TRS) on clozapine, using clinical investigations, antibody testing and to retrospectively apply diagnostic consensus criteria.Adult (18-65 years old) cases of FEP meeting inclusion criteria were recruited over three years and assessed using the Structured Clinical Interview for DSM-IV disorders (SCID). NMDAR-Ab was identified using a live cell-based assay (L-CBA). Seropositive cases were clinically investigated for features of encephalitis including neuro-imaging, EEG and CSF where possible. Serum was retested using immunohistochemistry (IHC) as part of diagnostic criteria guidelines. A cohort of patients with TRS was also recruited.112 FEP patients were recruited over 3 years. NMDAR-Ab seroprevalence was 4/112 (3.5%) cases. One case (1%) was diagnosed with definite NMDAR-Ab encephalitis and treated with immunotherapy. One of the three other seropositive cases met criteria for probable encephalitis. However all three were ultimately diagnosed with mood disorders with psychotic features. None have developed neurological features at three year follow up. 1/100 (1%) of patients with TRS was 100 patients with TRS were recruited. One case (1%) seropositive for NMDAR-Ab but did not meet criteria for encephalitis.NMDAR-Ab encephalitis as defined by consensus guidelines occured rarely in psychiatric services in this study. Further studies are needed to establish pathogenicity of serum NMDAR-Ab antibodies. Psychiatric services should be aware of the clinical features of encephalitis.

Background: The current coronavirus disease 2019 (COVID-19) pandemic began in Ireland with the first confirmed positive case in March 2020. In the early stages of the pandemic clinicians and researchers in two affiliated Dublin hospitals identified the need for a COVID-19 biobanking initiative to support and enhance research into the disease. Through large scale analysis of clinical, regional, and genetic characteristics of COVID-19 patients, biobanks have helped identify, and so protect, at risk patient groups The STTAR Bioresource has been created to collect and store data and linked biological samples from patients with SARS-CoV-2 infection and healthy and disease controls. Aim: The primary objective of this study is to build a biobank, to understand the clinical characteristics and natural history of COVID-19 infection with the long-term goal of research into improved disease understanding, diagnostic tests and treatments. Methods: This is a prospective dual-site cohort study across two tertiary acute university teaching hospitals. Patients are recruited from inpatient wards or outpatient clinics. Patients with confirmed COVID-19 infection as well as healthy and specific disease control groups are recruited. Biological samples are collected and a case report form detailing demographic and medical background is entered into the bespoke secure online Dendrite database. Impact: The results of this study will be used to inform national and international strategy on health service provision and disease management related to COVID-19. In common with other biobanks, study end points evolve over time as new research questions emerge. They currently include patient survival, occurrence of severe complications of the disease or its therapy, occurrence of persistent symptoms following recovery from the acute illness and vaccine responses.

Serological assays have been widely employed during the coronavirus disease 2019 (COVID-19) pandemic to measure antibody responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and to track seroconversion in populations. However, currently available assays do not allow determination of neutralization capacity within the assay protocol. Furthermore, commercial serology assays have a high buy-in cost that is inaccessible for many research groups. We have replicated the serological enzyme-linked immunosorbent assay for the detection of SARS-CoV-2 antibody isotypes, developed at the Icahn School of Medicine at Mount Sinai, New York. Additionally, we have modified the protocol to include a neutralization assay with only a minor modification to this protocol. We used this assay to screen local COVID-19 patient sera (n = 91) and pre-COVID-19 control sera (n = 103), and obtained approximate parity with approved commercial anti-nucleoprotein-based assays with these sera. Furthermore, data from our neutralization assay closely aligns with that generated using a spike-based pseudovirus infection model when a subset of patient sera was analyzed.

SARS-CoV-2 antibodies are an excellent indicator of past COVID-19 infection. As the COVID-19 pandemic progresses, retained sensitivity over time is an important quality in an antibody assay that is to be used for the purpose of population seroprevalence studies.We compared 5788 healthcare worker (HCW) serum samples on two serological assays (Abbott SARS-CoV-2 anti-nucleocapsid IgG and Roche Anti-SARS-CoV-2 anti-nucleocapsid Total Antibody) and a subset of samples (all Abbott assay positive or grayzone, n=485) on Wantai SARS-CoV-2 anti-spike Antibody ELISA. For 367 samples from HCW with previous PCR-confirmed SARS-CoV-2 infection we correlated the timing of infection with assay results.Overall seroprevalence was 4.2% on Abbott, 9.5% on Roche. Of those with previously confirmed infection, 41% (150/367) and 95% (348/367) tested positive on Abbott and Roche respectively. At 21 weeks (150 days) after confirmed infection, positivity on Abbott started to decline. Roche positivity was retained for the entire study period (33 weeks). Factors associated (P≤ 0.050) with Abbott seronegativity in those with previous PCR-confirmed infection included sex (male OR0.30;95%CI0.15-0.60), symptom severity (OR0.19 severe symptoms;95%CI0.05-0.61), ethnicity (OR0.28 Asian ethnicity;95%CI0.12-0.60) and time since PCR diagnosis (OR2.06 for infection 6 months previously;95%CI1.01-4.30. Wantai detected all previously confirmed infections.In our population, Roche detected antibodies up to at least seven months after natural infection with SARS-CoV-2. This may indicate that Roche is better suited than Abbott to population-based studies. Wantai demonstrated high sensitivity but sample selection was biased. The relationship between serological response and functional immunity to SARS-CoV-2 infection needs to be delineated.

Midlife Type 2 Diabetes Mellitus (T2DM) is associated with a greater risk of dementia in later life. Peripheral inflammation and its impact on cognition is proposed as one of the pathological mechanisms mediating this link. However, studies have primarily focused on older individuals with established cognitive impairment and a long duration of T2DM. Importantly, knowledge of which individuals with midlife T2DM who are at greatest risk of later cognitive decline is lacking. We examined the cross-sectional relationship between serum levels of 8 pro-inflammatory markers (IL-1β, IL-6, TNF-α, IL-8, MCP-1, CXCL10, IL-12p70, CRP) and performance on a detailed neuropsychological assessment battery in middle-aged adults with uncomplicated T2DM (N = 89; 52 ± 8.1 years, 47% female) and matched healthy controls (N = 50; 52 ± 8.3 years, 59% female). Linear regression was used to analyze associations between serum markers and cognitive performance in the overall cohort, followed by a T2DM∗protein concentration interaction analysis to identify any T2DM-specific effects. We observed a significant T2DM-specific association between serum TNF-α levels and scores on the Paired Associates Learning (PAL) task (β: −3.16, SE: 1.32, p = 0.01, Std. Beta: −0.94), a task with significant working memory demands previously implicated in T2DM-related cognitive dysfunction. However, this did not persist on controlling for multiple testing. We provide exploratory evidence for a significant T2DM-specific relationship between serum TNF-α and memory performance. These findings require further replication and longitudinal analysis with the aim of selecting-out individuals with midlife T2DM at risk of future cognitive decline for potential preventative interventions.

Fatigue is a common symptom in those presenting with symptomatic COVID-19 infection. However, it is unknown if COVID-19 results in persistent fatigue in those recovered from acute infection. We examined the prevalence of fatigue in individuals recovered from the acute phase of COVID-19 illness using the Chalder Fatigue Score (CFQ-11). We further examined potential predictors of fatigue following COVID-19 infection, evaluating indicators of COVID-19 severity, markers of peripheral immune activation and circulating pro-inflammatory cytokines. Of 128 participants (49.5 ± 15 years; 54% female), more than half reported persistent fatigue (52.3%; 45/128) at 10 weeks (median) after initial COVID-19 symptoms. There was no association between COVID-19 severity (need for inpatient admission, supplemental oxygen or critical care) and fatigue following COVID-19. Additionally, there was no association between routine laboratory markers of inflammation and cell turnover (leukocyte, neutrophil or lymphocyte counts, neutrophil-to-lymphocyte ratio, lactate dehydrogenase, C-reactive protein) or pro-inflammatory molecules (IL-6 or sCD25) and fatigue post COVID-19. Female gender and those with a pre-existing diagnosis of depression/anxiety were over-represented in those with fatigue. Our findings demonstrate a significant burden of post-viral fatigue in individuals with previous SARS-CoV-2 infection after the acute phase of COVID-19 illness. This study highlights the importance of assessing those recovering from COVID-19 for symptoms of severe fatigue, irrespective of severity of initial illness, and may identify a group worthy of further study and early intervention.

The ongoing coronavirus disease 2019 (COVID-19) pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current advisory guidelines for high-risk groups—including people with autoimmune disease taking immunosuppressive therapies—are to take increased precautions and avoid any unnecessary contacts. The aim of the DeCOmPRESS study is to define the disease course and immune profile of COVID-19 in immunosuppressed patients. We will clinically phenotype patients with ANCA-associated vasculitis (AAV) who develop COVID-19 using a customized REDCap data collection instrument embedded within the Rare Kidney Disease (RKD) Biobank. This dataset will be interoperable with the rheum-COVID, Global Rheumatology Alliance, and SPRINT-SARI datasets, facilitating international data linkage. Acute and convalescent blood samples will be analysed by flow cytometry and ELISA to define the immunophenotype and cytokine profile. Patients will track COVID-19 and AAV symptoms through a bespoke smartphone app. DeCOmPRESS study findings will rapidly inform management of immunosuppressed patients who contract COVID-19 by defining the natural history and immunological manifestations of the disease in these patients. We will also determine whether pre-existing immunosuppressant therapy lessens the cytokine storm associated with severe COVID-19 disease, thereby paradoxically improving rather than worsening clinical outcomes. This protocol document details the procedures for end-to-end completion of the DeCOmPRESS project and is complemented by an associated comprehensive Study Manual (accessible at: https://www.tcd.ie/medicine/thkc/decompress/).

Fatigue is a common symptom in those presenting with symptomatic COVID-19 infection. However, it is unknown if COVID-19 results in persistent fatigue in those recovered from acute infection. We examined the prevalence of fatigue in individuals recovered from the acute phase of COVID-19 illness using the Chalder Fatigue Score (CFQ-11). We further examined potential predictors of fatigue following COVID-19 infection, evaluating indicators of COVID-19 severity, markers of peripheral immune activation and circulating pro-inflammatory cytokines. Of 128 participants (49.5 ± 15 years; 54% female), more than half reported persistent fatigue (67/128; 52.3%) at median of 10 weeks after initial COVID-19 symptoms. There was no association between COVID-19 severity (need for inpatient admission, supplemental oxygen or critical care) and fatigue following COVID-19. Additionally, there was no association between routine laboratory markers of inflammation and cell turnover (leukocyte, neutrophil or lymphocyte counts, neutrophil-to-lymphocyte ratio, lactate dehydrogenase, C-reactive protein) or pro-inflammatory molecules (IL-6 or sCD25) and fatigue post COVID-19. Female gender and those with a pre-existing diagnosis of depression/anxiety were over-represented in those with fatigue. Our findings demonstrate a significant burden of post-viral fatigue in individuals with previous SARS-CoV-2 infection after the acute phase of COVID-19 illness. This study highlights the importance of assessing those recovering from COVID-19 for symptoms of severe fatigue, irrespective of severity of initial illness, and may identify a group worthy of further study and early intervention.

Summary Coeliac disease is a gluten-sensitive enteropathy that develops in genetically susceptible individuals. The disease exhibits many features of an autoimmune disorder. These include the production of highly specific anti-endomysial autoantibodies directed against the enzyme tissue transglutaminase. It is well accepted that wheat-, barley- and rye-based foods should be excluded in the gluten-free diet. Although several studies report that oats ingestion is safe in this diet, the potential toxicity of oats remains controversial. In the current study, 46 coeliac patients ingested oats for 1 year and were investigated for a potential immunogenic or toxic effect. Stringent clinical monitoring of these patients was performed and none experienced adverse effects, despite ingestion of a mean of 286 g of oats each week. Routine histological analysis of intestinal biopsies showed improvement or no change in 95% of the samples examined. Furthermore, tissue transglutaminase expression in biopsy samples, determined quantitatively using the IN Cell Analyzer, was unchanged. Employing immunohistochemistry, oats ingestion was not associated with changes in intraepithelial lymphocyte numbers or with enterocyte proliferation as assessed by Ki-67 staining. Finally, despite the potential for tissue transglutaminase to interact with oats, neither endomysial nor tissue transglutaminase antibodies were generated in any of the patients throughout the study. To conclude, this study reaffirms the lack of oats immunogenicity and toxicity to coeliac patients. It also suggests that the antigenic stimulus caused by wheat exposure differs fundamentally from that caused by oats.

Common variable immunodeficiency (CVID) is a primary immunoglobulin deficiency characterized by recurrent infections and complications, including autoimmunity, enteropathy, polyclonal lymphocytic infiltration or lymphoid malignancy. Innate T cells can support B cell maturation and antibody production. We investigated the numbers, phenotypes and functions of circulating B cell, γδ T cell, invariant natural killer T (iNKT) cell and mucosal-associated invariant T (MAIT) cell subsets in 23 CVID patients and 27 healthy controls. Switched-memory B cells and plasmablasts were depleted in CVID patients (p

The IN Cell Analyzer 1000 possesses several distinguishing features that make it a valuable tool in research today. This fully automated high content screening (HCS) system introduced quantitative fluorescent microscopy with computerized image analysis for use in cell-based analysis. Previous studies have focused on live cell assays, where it has proven to be a powerful and robust method capable of providing reproducible, quantitative data. Using HCS as a tool to investigate antigen expression in duodenal biopsies, we developed a novel approach to tissue positioning and mapping. We adapted IN Cell Analyzer 1000's image acquisition and analysis software for the investigation of tissue transglutaminase (tTG) and smooth muscle alpha-actin (SM α-actin) staining in paraffin-embedded duodenal tissue sections from celiac patients and healthy controls. These innovations allowed a quantitative analysis of cellular structure and protein expression. The results from routine biopsy material indicated the intensity of protein expression was altered in celiac disease compared to normal biopsy material.

We describe four children with a novel primary immunodeficiency consisting of specific natural-killer (NK) cell deficiency and susceptibility to viral diseases. One child developed an Epstein-Barr virus–driven lymphoproliferative disorder; two others developed severe respiratory illnesses of probable viral etiology. The four patients are related and belong to a large inbred kindred of Irish nomadic descent, which suggests autosomal recessive inheritance of this defect. A genomewide scan identified a single 12-Mb region on chromosome 8p11.23-q11.21 that was linked to this immunodeficiency (maximum LOD score 4.51). The mapping of the disease-causing genomic region paves the way for the identification of a novel pathway governing NK cell differentiation in humans.

The IN Cell Analyzer 1000 possesses several distinguishing features that make it a valuable tool in research today. This fully automated high content screening (HCS) system introduced quantitative fluorescent microscopy with computerized image analysis for use in cell-based analysis. Previous studies have focused on live cell assays, where it has proven to be a powerful and robust method capable of providing reproducible, quantitative data. Using HCS as a tool to investigate antigen expression in duodenal biopsies, we developed a novel approach to tissue positioning and mapping. We adapted IN Cell Analyzer 1000's image acquisition and analysis software for the investigation of tissue transglutaminase (tTG) and smooth muscle alpha-actin (SM α-actin) staining in paraffin-embedded duodenal tissue sections from celiac patients and healthy controls. These innovations allowed a quantitative analysis of cellular structure and protein expression. The results from routine biopsy material indicated the intensity of protein expression was altered in celiac disease compared to normal biopsy material.

IL-2 and IL-15 are lymphocyte growth factors produced by different cell types with overlapping functions in immune responses. Both cytokines costimulate lymphocyte proliferation and activation, while IL-15 additionally promotes the development and survival of NK cells, NKT cells, and intraepithelial lymphocytes. We have investigated the effects of IL-2 and IL-15 on proliferation, cytotoxicity, and cytokine secretion by human PBMC subpopulations in vitro. Both cytokines selectively induced the proliferation of NK cells and CD56(+) T cells, but not CD56(-) lymphocytes. All NK and CD56(+) T cell subpopulations tested (CD4(+), CD8(+), CD4(-)CD8(-), alphabetaTCR(+), gammadeltaTCR(+), CD16(+), CD161(+), CD158a(+), CD158b(+), KIR3DL1(+), and CD94(+)) expanded in response to both cytokines, whereas all CD56(-) cell subpopulations did not. Therefore, previously reported IL-15-induced gammadelta and CD8(+) T cell expansions reflect proliferations of NK and CD56(+) T cells that most frequently express these phenotypes. IL-15 also expanded CD8alpha(+)beta(-) and Valpha24Vbeta11 TCR(+) T cells. Both cytokines stimulated cytotoxicity by NK and CD56(+) T cells against K562 targets, but not the production of IFN-gamma, TNF-alpha, IL-2, or IL-4. However, they augmented cytokine production in response to phorbol ester stimulation or CD3 cross-linking by inducing the proliferation of NK cells and CD56(+) T cells that produce these cytokines at greater frequencies than other T cells. These results indicate that IL-2 and IL-15 act at different stages of the immune response by expanding and partially activating NK receptor-positive lymphocytes, but, on their own, do not influence the Th1/Th2 balance of adaptive immune responses.

International audience; Natural killer (NK) cells are circulating cytotoxic lymphocytes that exert potent and nonredundant antiviral activity and antitumoral activity in the mouse; however, their function in host defense in humans remains unclear. Here, we investigated 6 related patients with autosomal recessive growth retardation, adrenal insufficiency, and a selective NK cell deficiency characterized by a lack of the CD56(dim) NK subset. Using linkage analysis and fine mapping, we identified the disease-causing gene, MCM4, which encodes a component of the MCM2-7 helicase complex required for DNA replication. A splice-site mutation in the patients produced a frameshift, but the mutation was hypomorphic due to the creation of two new translation initiation methionine codons downstream of the premature termination codon. The patients' fibroblasts exhibited genomic instability, which was rescued by expression of WT MCM4. These data indicate that the patients' growth retardation and adrenal insufficiency likely reflect the ubiquitous but heterogeneous impact of the MCM4 mutation in various tissues. In addition, the specific loss of the NK CD56(dim) subset in patients was associated with a lower rate of NK CD56(bright) cell proliferation, and the maturation of NK CD56(bright) cells toward an NK CD56(dim) phenotype was tightly dependent on MCM4-dependent cell division. Thus, partial MCM4 deficiency results in a genetic syndrome of growth retardation with adrenal insufficiency and selective NK deficiency.

Summary A reliable biomarker of disease activity in psoriasis would be helpful for management, especially if this gave early information on treatment efficacy. This study investigated whether serum levels of soluble (s)CD163 correlated with psoriasis activity as assessed by the Psoriasis Area and Severity Index (PASI). CD163, a glycoprotein molecule expressed on macrophages and dendritic cells, is cleaved from the surface of these cells in some inflammatory diseases, and sCD163 levels have been shown to correlate with disease activity in other disorders. In this study, levels of sCD163 did not correlate with PASI in the patients (P = 0.56). Five patients had moderately increased PASI (12.6–20.3) but their sCD163 levels were within the normal range. From this study, it seems that sCD163 levels do not correlate with the inflammatory process in the skin of patients with psoriasis and thus sCD163 is not likely to be a useful biomarker for this disease.