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Background: Assessment of T-cell receptor excision circles (TRECs) in dried blood spots of newborns allows the detection of severe combined immunodeficiency (SCID) (T cells <300/μL at birth) with a presumed sensitivity of 100%. TREC screening also identifies patients with selected combined immunodeficiency (CID) (T cells >300/μL, yet <1500/μL at birth). Nevertheless, relevant CIDs that would benefit from early recognition and curative treatment pass undetected., Objective: We hypothesized that TREC screening at birth cannot identify CIDs that develop with age., Methods: We analyzed the number of TRECs in dried blood spots in archived Guthrie cards of 22 children who had been born in the Berlin-Brandenburg area between January 2006 and November 2018 and who had undergone hematopoietic stem-cell transplantation (HSCT) for inborn errors of immunity., Results: All patients with SCID would have been identified by TREC screening, but only 4 of 6 with CID. One of these patients had immunodeficiency, centromeric instability, and facial anomalies syndrome type 2 (ICF2). Two of 3 patients with ICF whom we have been following up at our institution had TREC numbers above the cutoff value suggestive of SCID at birth. Yet all patients with ICF had a severe clinical course that would have justified earlier HSCT., Conclusions: In ICF, naïve T cells may be present at birth, yet they decline with age. Therefore, TREC screening cannot identify these patients. Early recognition is nevertheless crucial, as patients with ICF benefit from HSCT early in life., (Copyright © 2023 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Infections are prevalent after spinal cord injury (SCI), constitute the main cause of death and are a rehabilitation confounder associated with impaired recovery. We hypothesize that SCI causes an acquired lesion-dependent (neurogenic) immune suppression as an underlying mechanism to facilitate infections. The international prospective multicentre cohort study (SCIentinel; protocol registration DRKS00000122; n = 111 patients) was designed to distinguish neurogenic from general trauma-related effects on the immune system. Therefore, SCI patient groups differing by neurological level, i.e. high SCI [thoracic (Th)4 or higher]; low SCI (Th5 or lower) and severity (complete SCI; incomplete SCI), were compared with a reference group of vertebral fracture (VF) patients without SCI. The primary outcome was quantitative monocytic Human Leukocyte Antigen-DR expression (mHLA-DR, synonym MHC II), a validated marker for immune suppression in critically ill patients associated with infection susceptibility. mHLA-DR was assessed from Day 1 to 10 weeks after injury by applying standardized flow cytometry procedures. Secondary outcomes were leucocyte subpopulation counts, serum immunoglobulin levels and clinically defined infections. Linear mixed models with multiple imputation were applied to evaluate group differences of logarithmic-transformed parameters. Mean quantitative mHLA-DR [ln (antibodies/cell)] levels at the primary end point 84 h after injury indicated an immune suppressive state below the normative values of 9.62 in all groups, which further differed in its dimension by neurological level: high SCI [8.95 (98.3% confidence interval, CI: 8.63; 9.26), n = 41], low SCI [9.05 (98.3% CI: 8.73; 9.36), n = 29], and VF without SCI [9.25 (98.3% CI: 8.97; 9.53), n = 41, P = 0.003]. Post hoc analysis accounting for SCI severity revealed the strongest mHLA-DR decrease [8.79 (95% CI: 8.50; 9.08)] in the complete, high SCI group, further demonstrating delayed mHLA-DR recovery [9.08 (95% CI: 8.82; 9.38)] and showing a difference from the VF controls of -0.43 (95% CI: -0.66; -0.20) at 14 days. Complete, high SCI patients also revealed constantly lower serum immunoglobulin G [-0.27 (95% CI: -0.45; -0.10)] and immunoglobulin A [-0.25 (95% CI: -0.49; -0.01)] levels [ln (g/l × 1000)] up to 10 weeks after injury. Low mHLA-DR levels in the range of borderline immunoparalysis (below 9.21) were positively associated with the occurrence and earlier onset of infections, which is consistent with results from studies on stroke or major surgery. Spinal cord injured patients can acquire a secondary, neurogenic immune deficiency syndrome characterized by reduced mHLA-DR expression and relative hypogammaglobulinaemia (combined cellular and humoral immune deficiency). mHLA-DR expression provides a basis to stratify infection-risk in patients with SCI., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Guarantors of Brain.)

Background: Non-pharmaceutical interventions (NPI) during the COVID-19 pandemic aimed at prevention of SARS-CoV-2 transmission also influenced transmission of viruses other than SARS-CoV-2. The aim of this study was to describe and compare the burden of common viral respiratory and gastrointestinal infections in children admitted to Berlin University Children's Hospital (BCH) before and during the COVID-19 pandemic at different levels of public NPI measures., Methods: In this retrospective study, we analyzed the frequency of detection of common human respiratory and gastrointestinal viruses from January 2016 through January 2022 in all patients admitted to BCH. We compared virus detection before and during the COVID-19 pandemic at different levels of public NPI measures., Results: The frequency of detection of seasonal enveloped and non-enveloped viruses [Boca-, Corona-, Influenza-, Metapneumo-, Parainfluenza-, Rota-, and Respiratory Syncytial Viruses (RSV)] was diminished during the COVID-19 pandemic, whereas detection rates of non-seasonal viruses (Rhino-/Entero-, and Adenoviruses) were stable during the pandemic. After withdrawal of major NPI measures, we observed an out of season surge of the detection rates of Boca-, Corona-, Parainfluenzaviruses, and RSV. In contrast, no increased detection frequency was observed for Influenza-, Metapneumo-, and Rotaviruses as of January 2022., Conclusion: Corona-, Boca-, Parainfluenzaviruses, and RSV returned as frequently detected pathogens after withdrawal of major NPI measures. The out of season rise might be attributed to an "immune-debt" due to missing contact to viral antigens resulting in waning of population immunity during the COVID-19 pandemic., Competing Interests: Authors NU, AE, AK, and HB were employed by Labor Berlin GmbH, a joint subsidiary of the public hospitals Charité Universitätsmedizin Berlin and Vivantes — Netzwerk für Gesundheit GmbH. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Terliesner, Unterwalder, Edelmann, Corman, Knaust, Rosenfeld, Gratopp, Ringe, Martin, von Bernuth, Mall and Kallinich.)

Objectives: To evaluate and compare the diagnostic accuracy of SIGLEC1, a surrogate marker of type I IFN, with established biomarkers in an inception cohort of systemic lupus erythematosus (SLE)., Methods: SIGLEC1 was analysed by flow cytometry in 232 patients referred to our institution with suspected SLE between October 2015 and September 2020., Results: SLE was confirmed in 76 of 232 patients (32.8 %) according to the 2019 EULAR/ACR classification criteria and their SIGLEC1 values were significantly higher compared with patients without SLE (P <0.0001). A sensitivity of 98.7 %, a specificity of 82.1 %, a negative predictive value (NPV) of 99.2 % and a positive predictive value (PPV) of 72.8 % were calculated for SIGLEC1. Adjusted to the highest reported prevalence of SLE, the NPV and PPV were >99.9 % and 0.1 %, respectively. Using receiver operating characteristic (ROC) analysis and DeLong testing, the area under the curve (AUC) for SIGLEC1 (AUC = 0.95) was significantly higher than for ANA (AUC = 0.88, P = 0.031), C3 (AUC = 0.83, P = 0.001) and C4 (AUC = 0.83, P = 0.002) but not for anti-dsDNA antibodies (AUC = 0.90, P = 0.163)., Conclusion: IFN-I pathway activation is detectable in almost all newly diagnosed SLE patients. Thus, a negative test result for SIGLEC1 is powerful to exclude SLE in suspected cases., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Purpose: Six to 19% of critically ill COVID-19 patients display circulating auto-antibodies against type I interferons (IFN-AABs). Here, we establish a clinically applicable strategy for early identification of IFN-AAB-positive patients for potential subsequent clinical interventions., Methods: We analyzed sera of 430 COVID-19 patients from four hospitals for presence of IFN-AABs by ELISA. Binding specificity and neutralizing activity were evaluated via competition assay and virus-infection-based neutralization assay. We defined clinical parameters associated with IFN-AAB positivity. In a subgroup of critically ill patients, we analyzed effects of therapeutic plasma exchange (TPE) on the levels of IFN-AABs, SARS-CoV-2 antibodies and clinical outcome., Results: The prevalence of neutralizing AABs to IFN-α and IFN-ω in COVID-19 patients from all cohorts was 4.2% (18/430), while being undetectable in an uninfected control cohort. Neutralizing IFN-AABs were detectable exclusively in critically affected (max. WHO score 6-8), predominantly male (83%) patients (7.6%, 18/237 for IFN-α-AABs and 4.6%, 11/237 for IFN-ω-AABs in 237 patients with critical COVID-19). IFN-AABs were present early post-symptom onset and at the peak of disease. Fever and oxygen requirement at hospital admission co-presented with neutralizing IFN-AAB positivity. IFN-AABs were associated with lower probability of survival (7.7% versus 80.9% in patients without IFN-AABs). TPE reduced levels of IFN-AABs in three of five patients and may increase survival of IFN-AAB-positive patients compared to those not undergoing TPE., Conclusion: IFN-AABs may serve as early biomarker for the development of severe COVID-19. We propose to implement routine screening of hospitalized COVID-19 patients for rapid identification of patients with IFN-AABs who most likely benefit from specific therapies., (© 2022. The Author(s).)

Objective: To evaluate sialic acid binding Ig-like lectin 1 (SIGLEC1) expression on monocytes by flow cytometry as a type I interferon biomarker in idiopathic inflammatory myopathies (IIM)., Methods: We performed a retrospective analysis of adult and paediatric patients with the diagnosis of IIM. SIGLEC1 expression was assessed by flow cytometry and was compared with Physician Global Assessment or Childhood Myositis Assessment Scale disease activity scores. Mann Whitney U test and receiver operating characteristic curves were used for cross-sectional data analysis (n=96), two-level mixed-effects linear regression model for longitudinal analyses (n=26, 110 visits). Response to treatment was analysed in 14 patients within 12 months, using Wilcoxon test. SIGLEC1 was compared with interferon-stimulated gene 15/MxA status by immunohistochemical staining of muscle biopsies (n=17)., Results: 96 patients with adult (a) and juvenile (j) dermatomyositis (DM, n=38), antisynthetase syndrome (AS, n=19), immune-mediated necrotising myopathy (IMNM, n=8), inclusion body myositis (IBM, n=9) and overlap myositis (n=22) were included. SIGLEC1 distinguished significantly between active and inactive disease with an area under the curve of 0.92 (95% CI 0.83 to 1) in DM and correlated with disease activity longitudinally (aDM: standardised beta=0.54, p<0.001; jDM: standardised beta=-0.70, p<0.001). Response to treatment in DM was associated with a decreasing SIGLEC1 (p<0.01, Wilcoxon test). SIGLEC1 was found upregulated in 8 of 19 patients with AS, 2 of 9 patients with IBM but not in IMNM., Conclusion: SIGLEC1 is a candidate biomarker to assess type I interferon activity in IIM and proved useful for monitoring disease activity and response to treatment in juvenile and adult DM., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: To describe a German cohort of patients with juvenile dermatomyositis (JDM) and to evaluate clinical manifestations, disease course and prognosis in JDM patients with a certain myositis-specific autoantibody., Methods: Cross-sectional data on patients with JDM documented in the National Paediatric Rheumatologic Database in Germany between 2014 and 2016 were analysed. In a subgroup of the cohort, MSAs were determined with a commercial multiplex array, and a retrospective chart review was conducted to specify the clinical phenotype and patient outcome., Results: The total cohort consisted of 196 patients with JDM (mean age 12.2±4.0 years, mean disease duration 5.1±3.8 years, 70% female). Apart from typical skin changes and muscle weakness, 41% of patients also had arthritis and/or contractures, 27% had calcinosis and approximately 10% had interstitial lung disease. Immunoblot testing was performed on the sera of 91 (46%) patients, detecting MSAs in 44% of patients. Patient groups with specific MSAs differed in clinical characteristics such as calcinosis, dysphagia, and lung and joint involvement. The extent of muscle weakness evaluated by the Childhood Myositis Assessment Scale was significantly associated with an increased level of creatine kinase. Patients with anti-MDA5 were particularly affected by polyarthritis of the small joints. After 5 years, 51 patients of the MSA cohort (56.0%) achieved an inactive disease state, 12/51 (23.5%) were off therapy., Conclusions: Patients with JDM in Germany show a broad spectrum of clinical manifestations that can be grouped into homogeneous groups using MSA, which also helps to predict the course and prognosis of the disease.

Autoantibodies against IFN-α and IFN-ω (type I IFNs) were recently reported as causative for severe COVID-19 in the general population. Autoantibodies against IFN-α and IFN-ω are present in almost all patients with autoimmune polyendocrine syndrome type 1 (APS-1) caused by biallelic deleterious or heterozygous dominant mutations in AIRE. We therefore hypothesized that autoantibodies against type I IFNs also predispose patients with APS-1 to severe COVID-19. We prospectively studied 6 patients with APS-1 between April 1, 2020 and April 1, 2021. Biobanked pre-COVID-19 sera of APS-1 subjects were tested for neutralizing autoantibodies against IFN-α and IFN-ω. The ability of the patients' sera to block recombinant human IFN-α and IFN-ω was assessed by assays quantifying phosphorylation of signal transducer and activator of transcription 1 (STAT1) as well as infection-based IFN-neutralization assays. We describe 4 patients with APS-1 and preexisting high titers of neutralizing autoantibodies against IFN-α and IFN-ω who contracted SARS-CoV-2, yet developed only mild symptoms of COVID-19. None of the patients developed dyspnea, oxygen requirement, or high temperature. All infected patients with APS-1 were females and younger than 26 years of age. Clinical penetrance of neutralizing autoantibodies against type I IFNs for severe COVID-19 is not complete.

Background: To analyse the validity of membrane-bound SIGLEC1 (CD169) as a sensitive biomarker for monitoring disease activity in pediatric systemic lupus erythematosus (SLE)., Methods: 27 children and adolescents with SLE were followed for a mean of 13.5 months. During consecutive routine visits SLEDAI-2k, C3, C4 and ds-DNA values were determined. Additionally, expression of SIGLEC1 on monocytes was determined by flow cytometry. The amount of PE-labelled CD169 mAb bound per monocyte was analyzed using QuantiBRITE™ PE tubes. Associations between biomarkers and the clinical course were investigated by regression analysis., Results: In general, SIGLEC1 expression is high on SLE-derived monocytes (mean 6 359 (SD 6 056) molecules/monocyte, cut-off 2 500 molecules/monocyte), all patients with newly diagnosed SLE exhibit elevated expression (mean 13366 (SD 7 750) molecules/monocyte). Changes (Δ) in SIGLEC1 levels during the clinical course is the only biomarker that significantly correlates with the change in SLEDAI-2k (beta ST  = 0.28, p = 0.001). At follow-up visit, a clinically important worsening was experienced by 47.6% of patients with a Δ SIGLEC1 > 2 151 molecules/cell (OR 5.31) and 72.4% with a Δ SIGLEC1 > 756 molecules/cell (OR 8.90). Conversely, 36.4% of patients with a Δ SIGLEC1 < -2 818 molecules/cell (OR 4.16, percentiles as cut-off criteria) and 50.0% of patients with a Δ SIGLEC1 < -1 370 molecules/cell (OR 3.55, application of Youden index) showed clinical improvement. SIGLEC1 expression correlates inversely with the amount of therapeutically applied hydroxychloroquine (p < 0.001)., Conclusions: SIGLEC1 expression on monocytes is a sensitive biomarker for adjusting disease activity in childhood SLE and represents a promising and easily applicable tool for disease monitoring.

Familial Mediterranean fever (FMF) is caused by mutations within the Mediterranean fever ( MEFV ) gene. Disease severity depends on genotype and gene dose with most serious clinical courses observed in patients with M694V homozygosity. Neutrophils are thought to play an important role in the initiation and perpetuation of inflammatory processes in FMF, but little is known about the specific characteristics of these cells in FMF patients. To further characterize neutrophilic inflammatory responses in FMF and to delineate gene-dose effects on a cellular level, we analyzed cytokine production and activation levels of isolated neutrophils derived from patients and subjects with distinct MEFV genotypes, as well as healthy and disease controls. Serum levels of interleukin-18 (IL-18) (median 11,485 pg/ml), S100A12 (median 9,726 ng/ml), and caspase-1 (median 394 pg/ml) were significantly increased in patients with homozygous M694V mutations. Spontaneous release of S100A12, caspase-1, proteinase 3, and myeloperoxidase (MPO) was restricted to ex vivo cultured neutrophils derived from patients with two pathogenic MEFV mutations. IL-18 secretion was highest in patients with two mutations but also increased in neutrophils from healthy heterozygous MEFV mutation carriers, exhibiting an ex vivo gene-dose effect, which was formerly described by us in patients' serum. CD62L (l-selectin) was spontaneously shed from the surface of ex vivo cultured neutrophils [median of geometric mean fluorescence intensity (gMFI) after 5 h: 28.8% of the initial level]. While neutrophils derived from healthy heterozygous mutation carriers again showed a gene-dose effect (median gMFI: 67.1%), healthy and disease controls had significant lower shedding rates (median gMFI: 83.6 and 82.9%, respectively). Co-culture with colchicine and/or stimulation with adenosine triphosphate (ATP) and lipopolysaccharide (LPS) led to a significant increase in receptor shedding. Neutrophils were not prevented from spontaneous shedding by blocking IL-1 or the NLRP3 inflammasome. In summary, the data demonstrate that ex vivo cultured neutrophils derived from FMF patients display a unique phenotype with spontaneous release of high amounts of IL-18, S100A12, MPO, caspase-1, and proteinase 3 and spontaneous activation as demonstrated by the loss of CD62L. Neutrophilic activation seems to be independent from IL-1 activation and displays a gene-dose effect that may be responsible for genotype-dependent phenotypes., (Copyright © 2020 Stoler, Freytag, Orak, Unterwalder, Henning, Heim, von Bernuth, Krüger, Winkler, Eschenhagen, Seipelt, Mall, Foell, Kessel, Wittkowski and Kallinich.)

Objective: To systematically analyze soluble interleukin-2 receptor (sIL-2R) in CSF as a diagnostic and disease activity biomarker in patients with sarcoidosis involving the CNS (neurosarcoidosis)., Methods: sIL-2R was determined by chemiluminescent immunoassays in CSF/serum samples from patients with neurosarcoidosis (n = 23), MS (n = 19), neurotuberculosis (n = 8), viral (n = 18) and bacterial (n = 9) meningitis, cerebral lymphoma (n = 15), Guillain-Barré syndrome (n = 8), and 115 patients with noninflammatory neurologic diseases (NINDs) as controls. The sIL-2R index was calculated by dividing the CSF/serum sIL-2R quotient (Q sIL-2R ) through the CSF/serum albumin quotient (Q Alb ). sIL-2R quotient diagrams were established by plotting Q sIL-2R against Q Alb . sIL-2R levels were correlated with clinical, MRI, and CSF disease activity markers of neurosarcoidosis., Results: Patients with neurosarcoidosis had higher CSF sIL-2R, Q sIL-2R , and sIL-2R index values than patients with NINDs ( p < 0.0001 for all pairwise group comparisons). sIL-2R quotient diagrams demonstrated an intrathecal sIL-2R synthesis in >50% of neurosarcoidosis samples. Similar findings were observed in viral/bacterial meningitis, CNS lymphoma, and, most pronounced, in neurotuberculosis, but not in patients with MS. CSF sIL-2R parameters were associated with clinical disease activity, leptomeningeal gadolinium enhancement, and the CSF white cell count in patients with neurosarcoidosis., Conclusions: CSF sIL-2R parameters are elevated in patients with neurosarcoidosis, but this finding is not specific for neurosarcoidosis. Nevertheless, CSF sIL-2R parameters may help distinguishing neurosarcoidosis from MS and are associated with clinical, radiologic, and CSF disease activity markers of neurosarcoidosis., Classification of Evidence: This study provides Class II evidence that CSF sIL-2R parameters distinguish neurosarcoidosis from NINDs and MS., (Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Purpose: NEMO-deficient patients present with variable degrees of immunodeficiency. Accordingly, treatment ranges from antibiotic prophylaxis and/or IgG-substitution to allogenic hematopoietic stem cell transplantation (HSCT). The correct estimation of the immunodeficiency is essential to avoid over- as well as under-treatment. We compare the immunological phenotype of a NEMO-deficient patient with a newly-described splice site mutation that causes truncation of the NEMO zinc-finger (ZF) domain and a severe clinical course with the immunological phenotype of three NEMO-deficient patients with missense mutations and milder clinical courses and all previously published patients., Methods: Lymphocyte subsets, proliferation, and intracellular NEMO-expression were assessed by FACS. NF-κB signal transduction was determined by measuring IκBα-degradation and the production of cytokines upon stimulation with TNF-α, IL-1β, and TLR-agonists in immortalized fibroblasts and whole blood, respectively., Results: The patient with truncated ZF-domain of NEMO showed low levels of IgM and IgG, reduced class-switched memory B cells, almost complete skewing towards naïve CD45RA + T cells, impaired T cell proliferation as well as cytokine production upon stimulation with TNF-α, IL-1β, and TLR-agonists. He suffered from severe infections (sepsis, pneumonia, osteomyelitis) during infancy. In contrast, three patients with missense mutations in IKBKG presented neither skewing of T cells towards naïvety nor impaired T cell proliferation. They are stable on prophylactic IgG-substitution or even off any prophylactic treatment., Conclusion: The loss of the ZF-domain and the impaired T cell proliferation accompanied by almost complete persistence of naïve T cells despite severe infections are suggestive for a profound immunodeficiency. Allogenic HSCT should be considered early for these patients before chronic sequelae occur.

Aim: Management of patients with infections within the Emergency Department (ED) is challenging for practitioners, as the identification of infectious causes remains difficult with current techniques. A new combination of two biomarkers was tested with a new rapid flow cytometry technique. Materials & methods: Subjects from the ED were tested for their CD64 on neutrophils (nCD64) and CD169 on monocytes (mCD169) levels and results were compared to their clinical records. Results: Among 139 patients, 29% had confirmed bacterial infections and 5% viral infections. nCD64 and mCD169 respectively showed 88 and 86% sensitivity and 90 and 100% specificity for identifying subjects in bacterial or viral conditions. Conclusion: This point-of-care technique could allow better management of patients in the ED.

Introduction: Haemophagocytic lymphohistiocytosis (HLH) in adults is characterised by toxic immune activation and a sepsis-like syndrome, leading to high numbers of undiagnosed cases and mortality rates of up to 68%. Early diagnosis and specific immune suppressive treatment are mandatory to avoid fatal outcome, but the diagnostic criteria (HLH-2004) are adopted from paediatric HLH and have not been validated in adults. Experimental studies suggest biomarkers to sufficiently diagnose HLH. However, biomarkers for the diagnosis of adult HLH have not yet been investigated., Methods and Analysis: The HEMICU (Diagnostic biomarkers for adult haemophagocytic lymphohistiocytosis in critically ill patients) study aims to estimate the incidence rate of adult HLH among suspected adult patients in intensive care units (ICUs). Screening for HLH will be performed in 16 ICUs of Charité - Universitätsmedizin Berlin. The inclusion criteria are bicytopaenia, hyperferritinaemia (≥500 µg/L), fever or when HLH is suspected by the clinician. Over a period of 2 years, we expect inclusion of about 100 patients with suspected HLH. HLH will be diagnosed if at least five of the HLH-2004 criteria are fulfilled, together with an expert review; all other included patients will serve as controls. Second, a panel of potential biomarker candidates will be explored. DNA, plasma and serum will be stored in a biobank. The primary endpoint of the study is the incidence rate of adult HLH among suspected adult patients during ICU stay. Out of a variety of measured biomarkers, this study furthermore aims to find highly potential biomarkers for the diagnosis of adult HLH in ICU. The results of this study will contribute to improved recognition and patient outcome of adult HLH in clinical routine., Ethics and Dissemination: The institutional ethics committee approved this study on 1 August 2018 (Ethics Committee of Charité - Universitätsmedizin Berlin, EA4/006/18). The results of the study will be disseminated in an international peer-reviewed journal and presented at international conferences., Trial Registration Number: NCT03510650., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Respiratory infections are the main cause of early death in patients with MECP2 duplication syndrome. We report on a 20-year-old patient with MECP2 duplication syndrome, IgG2/IgG4/IgA/IgM deficiency and polysaccharide-specific antibody deficiency, who had 46 episodes of pneumonia in his first 13 8/12 years of life. Immunoglobulin substitution, daily antibiotic prophylaxis with two agents and supportive measures reduced occurrence of pneumonia to four episodes in the following 6 2/12 years of life.

Background: MicroRNAs (miRNAs, miR) hold important roles in the posttranscriptional regulation of gene expression. Their function has been correlated with kidney disease, and they might represent a new class of biomarkers for frequent evaluation of renal graft status. We analyzed their potential in identifying severe T cell-mediated vascular rejection (TCMVR) (Banff 4-II/III) in kidney transplanted patients., Methods: Microarray experiments and semiquantitative real-time reverse transcription polymerase chain reaction were performed with total RNA isolated from blood cells of kidney graft recipients. Initial microarray analysis revealed 23 differentially expressed miRNAs distinguishing patients with TCMVR from patients with stable grafts. From these, we validated and further determined the expression of 6 differentially expressed miRNAs and 2 control miRNAs in 161 samples from patients with T cell-mediated rejection (Banff 3-Borderline, Banff 4-I/II/III), Banff-2 antibody-mediated rejection, Banff-5 interstitial fibrosis/tubular atrophy, in samples from stable patients and in samples from patients with urinary tract infection using real-time reverse transcription polymerase chain reaction., Results: Expression levels of all 6 candidate miRNAs were significantly downregulated in blood of TCMVR patients compared to the other groups and displayed high sensitivities and specificities for diagnosing TCMVR. The combination of 5 miRNAs, identified by an unbiased multivariate logistic regression followed by cross-validation, enhanced the sensitivity and specificity for the diagnosis of TCMVR after renal transplantation., Conclusions: The combined measurement of miRNA-15B, miRNA-16, miRNA-103A, miRNA-106A, and miRNA-107 may help to better identify TCMVR after renal transplantation in a precise and clinically applicable way.

Belatacept offers a new option for renal allograft recipients who are suffering from side effects of calcineurin inhibitors or mTOR inhibitors,which may result in renal and extrarenal benefits.We prospectively performed flow cytometric immunophenotyping with a T-cell panel. In total we were able to fully investigate the immunophenotypic change in 8 patients before and after conversion from calcineurin inhibitor (n = 5) or mTOR inhibitor (n=2) to Belatacept or additional administration (n=1). Cells were analysed pre conversion, 1 month, 3 months, 6 months and 12 months after first Belatacept administration. The percentage of central memory, naïve, effector memory and terminally differentiated effector memory CD4+ and CD4− T-cells was determined. CD28, CD25 and CD69 expression on CD4+ and CD4− T-cells was measured ex vivo and also after 3 days of mitogen stimulation. Intracellular cytokines IFNgamma and IL-2 were measured after polyclonal cellular stimulation. The expression of activation markers and intracellular cytokines as well as the percentage of T-cell subsets did not change significantly during the observation period compared to the time-point pre conversion. Therefore the conversion of calcineurin inhibitor or mTOR inhibitor to Belatacept seems to have no obvious impact on the immunophenotype of T-cells in patients after kidney transplantation.

Chronic fatigue syndrome (CFS) is a severe disease characterized by various symptoms of immune dysfunction. CFS onset is typically with an infection and many patients suffer from frequently recurrent viral or bacterial infections. Immunoglobulin and mannose binding lectin (MBL) deficiency are frequent causes for increased susceptibility to infections. In this study we retrospectively analysed 300 patients with CFS for immunoglobulin and MBL levels, and B-cell subset frequencies. 25% of the CFS patients had decreased serum levels of at least one antibody class or subclass with IgG3 and IgG4 subclass deficiencies as most common phenotypes. However, we found elevated immunoglobulin levels with an excess of IgM and IgG2 in particular in another 25% of patients. No major alteration in numbers of B cells and B-cell subsets was seen. Deficiency of MBL was found in 15% of the CFS patients in contrast to 6% in a historical control group. In a 2nd cohort of 168 patients similar frequencies of IgG subclass and MBL deficiency were found. Thus, humoral immune defects are frequent in CFS patients and are associated with infections of the respiratory tract., (Copyright © 2015 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.)

Aims: The risk of neonates for severe infection/sepsis is reciprocally proportional to gestational age and birth weight. As monocytes and dendritic cells (DC) are recognised key antigen-presenting immune cells, we aimed to elucidate whether neonatal age is associated with reduced expression of human-leukocyte antigen-DR (HLA-DR) antigens on subsets of monocytes and DCs., Methods: Forty-three consecutive neonates (20 male, mean gestational age 236.0±26.8 days; mean 1-min Apgar score 7.5±2.0) were included in a monocentric prospective observational analysis. Patients were grouped according to gestational age (n=15 full-term, n=28 pre-term defined as <33 weeks). Ten healthy adult volunteers were assessed also. Flow-cytometric assessment of HLA-DR expression was performed in subsets of peripheral blood myeloid and plasmacytoid DCs (MDC and PDC) and monocytes (CD14brightCD16negative/CD14positiveCD16positive/CD14dimCD16positive). Clinical and routine laboratory data were followed up., Results: At birth, leukocyte counts were increased in full-term neonates. Monocyte counts were significantly increased in neonates when compared with adults (all P<0.05). A significant numerical increase of CD14brightCD16negative and CD14positiveCD16positive monocytes was noted in pre-term and full-term neonates (all P<0.05), while HLA-DR expression in these subsets was significantly diminished (most pronounced in pre-term infants, P<0.0001). MDC and PDC HLA-DR expression was reduced also (all P<0.05). Clinical indices (e.g., pH, days on antibiotics/mechanical ventilation, fever/sepsis) were not found to correlate with immunological indices., Conclusions: We observed a markedly diminished HLA-DR expression on monocyte and DC subsets in pre-term and full-term neonates, which may contribute to impaired antimicrobial defence mechanisms in the early days of life.

The present study compared lymphocyte and T memory subsets in currently untreated patients with chronic inflammatory demyelinating polyneuropathy (CIDP) to glucocorticosteroid (GS) and intravenous immunoglobulin (IVIG) treated patients. Peripheral blood from 48 CIDP patients (21 untreated who were either treatment naïve or without treatment during the last 3 months, 17 IVIG and 10 GS treatment) and from 12 age-matched controls was evaluated using flow cytometric analysis. Our data demonstrate that long-term GS treatment is associated with reduced frequencies of total CD4+ T cells, CD4+ memory subsets and NK cells while long-term IVIG treatment is associated with alterations of the CD8+ memory compartment. Reduction of CD4+ naïve T cell counts may explain the observation that GS treatment induces prolonged clinical remission compared to IVIG treatment., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Purpose: Since we described for the first time a patient with IgG4 autoantibodies to IFN-γ more than 10 years ago, many patients with IFN-γ IgG4 autoantibodies have been described, mostly in Mongolian/ Asian patients with a particular HLA background and in association with disseminated nontuberculous mycobacterial infections. Very recently, the first Caucasian US patient was reported and we now present the case of a 65-year old Caucasian woman with severe disseminated Mycobacterium avium infection, cerebral toxoplasmosis and salmonella sepsis who was tested positive for IFN-γ deficiency due to unusual anti-IFN-γ IgG1 autoantibodies., Methods: IFN-γ production after ex vivo ConA stimulation of the patient's whole blood and isolated peripheral blood mononuclear cells was assessed. Anti-human IFN-γ antibodies were measured by Ig/Ig-subclass-specific ELISA. In vitro physiologic relevance and blocking capacity of IFN-γ-stimulation by patient's serum was analysed by flow cytometric assessment of cytokine-induced phosphorylation of pSTAT1(Y701)., Results: Severely impaired IFN-γ production in the patient's whole blood but normal production in peripheral blood mononuclear cells in the absence of autologous serum was observed. High titre anti-IFN-γ antibodies of the IgG1 subclass could be demonstrated in the patient's serum by ELISA. Further, the addition of patient's serum to IFN-γ-stimulated immune cells showed inhibition of STAT1 phosphorylation., Conclusions: IFN-γ autoantibodies of any IgG-isotype should be considered in patients with severe opportunistic infections independent of age at onset and ethnicity.

MECP2 (methyl CpG binding protein 2) duplication causes syndromic intellectual disability. Patients often suffer from life-threatening infections, suggesting an additional immunodeficiency. We describe for the first time the detailed infectious and immunological phenotype of MECP2 duplication syndrome. 17/27 analyzed patients suffered from pneumonia, 5/27 from at least one episode of sepsis. Encapsulated bacteria (S.pneumoniae, H.influenzae) were frequently isolated. T-cell immunity showed no gross abnormalities in 14/14 patients and IFNy-secretion upon ConA-stimulation was not decreased in 6/7 patients. In 6/21 patients IgG2-deficiency was detected - in 4/21 patients accompanied by IgA-deficiency, 10/21 patients showed low antibody titers against pneumococci. Supra-normal IgG1-levels were detected in 11/21 patients and supra-normal IgG3-levels were seen in 8/21 patients - in 6 of the patients as combined elevation of IgG1 and IgG3. Three of the four patients with IgA/IgG2-deficiency developed multiple severe infections. Upon infections pronounced acute-phase responses were common: 7/10 patients showed CRP values above 200 mg/l. Our data for the first time show systematically that increased susceptibility to infections in MECP2 duplication syndrome is associated with IgA/IgG2-deficiency, low antibody titers against pneumococci and elevated acute-phase responses. So patients with MECP2 duplication syndrome and low IgA/IgG2 may benefit from prophylactic substitution of sIgA and IgG.

Epstein-Barr virus (EBV) has long been discussed as a possible cause or trigger of Chronic Fatigue Syndrome (CFS). In a subset of patients the disease starts with infectious mononucleosis and both enhanced and diminished EBV-specific antibody titers have been reported. In this study, we comprehensively analyzed the EBV-specific memory B- and T-cell response in patients with CFS. While we observed no difference in viral capsid antigen (VCA)-IgG antibodies, EBV nuclear antigen (EBNA)-IgG titers were low or absent in 10% of CFS patients. Remarkably, when analyzing the EBV-specific memory B-cell reservoir in vitro a diminished or absent number of EBNA-1- and VCA-antibody secreting cells was found in up to 76% of patients. Moreover, the ex vivo EBV-induced secretion of TNF-α and IFN-γ was significantly lower in patients. Multicolor flow cytometry revealed that the frequencies of EBNA-1-specific triple TNF-α/IFN-γ/IL-2 producing CD4(+) and CD8(+) T-cell subsets were significantly diminished whereas no difference could be detected for HCMV-specific T-cell responses. When comparing EBV load in blood immune cells, we found more frequently EBER-DNA but not BZLF-1 RNA in CFS patients compared to healthy controls suggesting more frequent latent replication. Taken together, our findings give evidence for a deficient EBV-specific B- and T-cell memory response in CFS patients and suggest an impaired ability to control early steps of EBV reactivation. In addition the diminished EBV response might be suitable to develop diagnostic marker in CFS.

Background: Infections are the leading cause of death in the acute phase following spinal cord injury and qualify as independent risk factor for poor neurological outcome ("disease modifying factor"). The enhanced susceptibility for infections is not stringently explained by the increased risk of aspiration in tetraplegic patients, neurogenic bladder dysfunction, or by high-dose methylprednisolone treatment. Experimental and clinical pilot data suggest that spinal cord injury disrupts the balanced interplay between the central nervous system and the immune system. The primary hypothesis is that the Spinal Cord Injury-induced Immune Depression Syndrome (SCI-IDS) is 'neurogenic' including deactivation of adaptive and innate immunity with decreased HLA-DR expression on monocytes as a key surrogate parameter. Secondary hypotheses are that the Immune Depression Syndrome is i) injury level- and ii) severity-dependent, iii) triggers transient lymphopenia, and iv) causes qualitative functional leukocyte deficits, which may endure the post-acute phase after spinal cord injury., Methods/design: SCIentinel is a prospective, international, multicenter study aiming to recruit about 118 patients with acute spinal cord injury or control patients with acute vertebral fracture without neurological deficits scheduled for spinal surgery. The assessment points are: i) <31 hours, ii) 31-55 hours, iii) 7 days, iv) 14 days, and v) 10 weeks post-trauma. Assessment includes infections, concomitant injury, medication and neurological classification using American Spinal Injury Association impairment scale (AIS) and neurological level. Laboratory analyses comprise haematological profiling, immunophenotyping, including HLA-DR expression on monocytes, cytokines and gene expression of immune modulators. We provide an administrative interim analysis of the recruitment schedule of the trial., Discussion: The objectives are to characterize the dysfunction of the innate and adaptive immune system after spinal cord injury and to explore its proposed 'neurogenic' origin by analyzing its correlation with lesion height and severity. The trial protocol considers difficulties of enrolment in an acute setting, and loss to follow up. The administrative interim analysis confirmed the feasibility of the protocol. Better understanding of the SCI-IDS is crucial to reduce co-morbidities and thereby to attenuate the impact of disease modifying factors to protect neurological "outcome at risk". This putatively results in improved spinal cord injury medical care., Trial Registration Drks-Id: DRKS00000122 (German Clinical Trials Registry).

Background and Objectives: Major abdominal procedures are strongly associated with postoperative immunosuppression and subsequent increased patient morbidity. It is believed that laparoscopic surgery causes less depletion of the systemic immune function because of the reduced tissue trauma. Various cytokines and monocytic HLA-DR expression have been successfully implemented to assess postoperative immune function. The aim of our study was to show the difference in immunologic profiles after minimally invasive versus conventional liver resection., Methods: Ten animals underwent either laparoscopic or conventional open left lateral liver resection. Flow cytometric characteristics of HLA-DR expression on monocytes and lipopolysaccharide-stimulated cellular secretion of tumor necrosis factor α, interferon γ, interleukin 6, and interleukin 8 were measured and analyzed in ex vivo whole blood samples. Intraoperative and postoperative clinical outcome parameters were also documented and evaluated., Results: All animals survived the procedures. Postoperative complications were fever (n = 3), wound infections (n = 2), and biloma (n = 1). Open surgery showed a morbidity rate of 80% compared with 40% after laparoscopic surgery. Laparoscopic liver resection showed no postoperative immunoparalysis. Major histocompatibility complex class II expression in this group was elevated, whereas the open surgery group showed decreased major histocompatibility complex class II expression on postoperative day 1. Postoperative secretion of tumor necrosis factor , interleukin 6, and interferon was lower in the open surgery group. Elevated transaminase levels after laparoscopy might have resulted from an ischemia/reperfusion injury caused by the capnoperitoneum., Conclusion: Major immunoparalysis depression was not observed in either group. Laparoscopic surgery shows a tendency to improve immunologic recovery after liver resection.

There is growing evidence that adaptive immunity contributes to endogenous regeneration processes: For example, endogenous bone fracture repair is modulated by T cells even in the absence of infection. Because delayed or incomplete fracture healing is associated with poor long-term outcomes and high socioeconomic costs, we investigated the relationship between an individual's immune reactivity and healing outcome. Our study revealed that delayed fracture healing significantly correlated with enhanced levels of terminally differentiated CD8(+) effector memory T (TEMRA) cells (CD3(+)CD8(+)CD11a(++)CD28(-)CD57(+) T cells) in peripheral blood. This difference was long lasting, reflecting rather the individual's immune profile in response to lifelong antigen exposure than a post-fracture reaction. Moreover, CD8(+) TEMRA cells were enriched in fracture hematoma; these cells were the major producers of interferon-γ/tumor necrosis factor-α, which inhibit osteogenic differentiation and survival of human mesenchymal stromal cells. Accordingly, depletion of CD8(+) T cells in a mouse osteotomy model resulted in enhanced endogenous fracture regeneration, whereas a transfer of CD8(+) T cells impaired the healing process. Our data demonstrate the high impact of the individual adaptive immune profile on endogenous bone regeneration. Quantification of CD8(+) TEMRA cells represents a potential marker for the prognosis of the healing outcome and opens new opportunities for early and targeted intervention strategies.

Humoral rejection processes may lead to allograft injury and subsequent dysfunction. Today, only one B-cell-specific agent is in clinical use and the effects of standard and new immunosuppressant substances on B-cell activation and function are not fully clarified. The impact of sotrastaurin, mycophenolic acid and everolimus on human B-lymphocyte function was assessed by analysing proliferation, apoptosis, CD80/CD86 expression and immunoglobulin and IL-10 production in primary stimulated B cells. In addition, B-cell co-cultures with pre-activated T cells were performed to evaluate the effect of the different immunosuppressive agents on T-cell-dependent immunoglobulin production. Sotrastaurin did not inhibit B-cell proliferation, CD80/CD86 expression, and IgG production and had only minor effects on IgM levels at the highest concentration administered. In contrast, mycophenolic acid and everolimus had strong effects on all B-cell functions in a dose-dependent manner. All immunosuppressive agents caused decreased immunoglobulin levels in T-cell-dependent B-cell cultures. The data provided here suggest that mycophenolic acid and everolimus, but not sotrastaurin, are potent inhibitors of human B-lymphocyte function and activation., (© 2012 The Authors. Transplant International © 2012 European Society for Organ Transplantation.)

HSV-1 persistently infects almost 90% of our population; however, only 30% of the infected subjects suffer from recurrent herpes lesions, most frequently herpes labialis (HL). We hypothesized that variations in toll-like receptor (TLR) functions might contribute to HL susceptibility. In our study, the TLR-2/1,-3, and -7/8 responses of immune cell subsets derived from asymptomatic HSV-1 carriers were compared with responses of subjects with HL history. Remarkably, natural killer (NK) cells isolated from HL subjects showed significantly lower IFN-γ responses selectively to the TLR3 agonist poly(I:C). Furthermore, the TLR3 L412F genetic polymorphism was found to reduce NK cell TLR3-responsiveness and is associated with susceptibility to recurrent HL. The TLR3 response detected in HL total peripheral blood mononuclear cells (PBMCs), however, was not impaired, indicating restoration of NK cell TLR3-deficiency through co-stimulatory functions. In conclusion, our results suggest that decreased TLR3 response of NK cells is associated with HL susceptibility; and potentially explain why symptomatic outbreak of HL usually occurs after stress or prolonged UV light exposure, when host co-stimulatory functions are disturbed., (Copyright © 2012 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.)

Background: Polyomavirus associated nephropathy (PVAN) affects up to 10% of kidney transplant recipients and is a major risk factor for graft loss. Mannose-binding lectin (MBL) is an important recognition molecule of the innate immune system, and its deficiency has been associated with susceptibility to various infections. In transplantation, on the other hand, high MBL levels have been associated with increased tissue damage in ischemia-reperfusion models and poorer graft and patient survival in solid organ transplant patients. To investigate the relation between MBL and BK virus infection, post-transplant (post-Tx) MBL levels were determined in a cohort of de novo kidney transplant patients with and without BK viremia., Patients and Methods: 41 de novo kidney transplant patients with high (n=16, group 1) or low level BK viremia (n=25, group 2) and 64 patients without BK viremia (group 3) were included. In every patient, functional MBL levels were determined at 1-3 time points (days 30, 90 or 180) post-Tx using an MBL oligomer ELISA., Results: MBL levels remained unchanged between days 30 and 180 post-Tx independent of BKV viremia. Frequencies of MBL deficiency (<500 ng/mL) and MBL levels were not significantly different between the 3 groups. However, group 2 patients showed a trend towards lower MBL serum levels compared to group 1 patients, notably in patients without acute rejection (p=0.076)., Conclusion: MBL deficiency was not associated with higher risk for BK viremia. In contrast, we hypothesize that BK virus replication in patients with low MBL levels might imply lower risk for progression towards PVAN compared to patients with high MBL levels. This view is supported by recent data demonstrating local complement activation in BK nephropathy., (Copyright © 2011 Elsevier B.V. All rights reserved.)

We previously demonstrated a correlation between the frequency of CX3CR1-expressing human natural killer (NK) cells and disease activity in multiple sclerosis and showed that CX3CR1(high) NK cells were more cytotoxic than their CX3CR1(neg/low) counterparts. Here we aimed to determine whether human NK cell fractions defined by CX3CR1 represent distinct subtypes. Phenotypic and functional NK cell analyses revealed that, distinct from CX3CR1(high), CX3CR1(neg/low) NK cells expressed high amounts of type 2 cytokines, proliferated robustly in response to interleukin-2 and promoted a strong up-regulation of the key co-stimulatory molecule CD40 on monocytes. Co-expression analyses of CX3CR1 and CD56 demonstrated the existence of different NK cell fractions based on the surface expression of these two surface markers, the CX3CR1(neg) CD56(bright), CX3CR1(neg) CD56(dim) and CX3CR1(high) CD56(dim) fractions. Additional investigations on the expression of NK cell receptors (KIR, NKG2A, NKp30 and NKp46) and the maturation markers CD27, CD62L and CD57 indicated that CX3CR1 expression of CD56(dim) discriminated between an intermediary CX3CR1(neg)  CD56(dim) and fully mature CX3CR1(high) CD56(dim) NK cell fractions. Hence, CX3CR1 emerges as an additional differentiation marker that may link NK cell maturation with the ability to migrate to different organs including the central nervous system., (© 2011 The Authors. Immunology © 2011 Blackwell Publishing Ltd.)