Resolving the polygenic aetiology of a late onset combined immune deficiency caused by NFKB1 haploinsufficiency and modified by PIK3R1 and TNFRSF13B variants.

Genetic variants in PIK3CD, PIK3R1 and NFKB1 cause the primary immune deficiencies, activated PI3Kδ syndrome (APDS) 1, APDS2 and NFκB1 haploinsufficiency, respectively. We have identified a family with known or potentially pathogenic variants NFKB1, TNFRSF13B and PIK3R1. The study's aim was to describe their associated immune and cellular phenotypes and compare with individuals with monogenic disease. NFκB1 pathway function was measured by immunoblotting and PI3Kδ pathway activity by phospho-flow cytometry. p105/p50 expression was absent in two individuals but elevated pS6 only in the index case. Transfection of primary T cells demonstrated increased basal pS6 signalling due to mutant PIK3R1, but not mutant NFKB1 or their wildtype forms. We report on the presence of pathogenic variant NFKB1, with likely modifying variants in TNFRSF13B and PIK3R1 in a family. We describe immune features of both NFκB1 haploinsufficiency and APDS2, and the inhibition of excessive PI3K signalling by rapamycin in vitro.

Decreased ATM Function Causes Delayed DNA Repair and Apoptosis in Common Variable Immunodeficiency Disorders.

PURPOSE: Common variable immunodeficiency disorders (CVID) is characterized by low/absent serum immunoglobulins and susceptibility to bacterial infection. Patients can develop an infections-only phenotype or a complex disease course with inflammatory, autoimmune, and/or malignant complications. We hypothesized that deficient DNA repair mechanisms may be responsible for the antibody deficiency and susceptibility to inflammation and cancer in some patients. METHODS: Germline variants were identified following targeted sequencing of n = 252 genes related to DNA repair in n = 38 patients. NanoString nCounter PlexSet assay measured gene expression in n = 20 CVID patients and n = 7 controls. DNA damage and apoptosis were assessed by flow cytometry in n = 34 CVID patients and n = 11 controls. RESULTS: Targeted sequencing supported enrichment of rare genetic variants in genes related to DNA repair pathways with novel and rare likely pathogenic variants identified and an altered gene expression signature that distinguished patients from controls and complex patients from those with an infections-only phenotype. Consistent with this, flow cytometric analyses of lymphocytes following DNA damage revealed a subset of CVID patients whose immune cells have downregulated ATM, impairing the recruitment of other repair factors, delaying repair and promoting apoptosis. CONCLUSION: These data suggest that germline genetics and altered gene expression predispose a subset of CVID patients to increased sensitivity to DNA damage and reduced DNA repair capacity.

Towards evidence based emergency medicine: best BETs from the Manchester Royal Infirmary. BET 1: does restrictive fluid resuscitation in penetrating chest injury affect outcome?

A short cut review was carried out to establish whether restrictive fluid administration in penetrating thoracic trauma impacted on patients' mortality. 143 papers were found using the reported searches, of which three presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these are tabulated. It is concluded that there is paucity of relevant research and there is limited scientific evidence to inform fluid administration in these patients.

Pneumococcal conjugate and plain polysaccharide vaccines have divergent effects on antigen-specific B cells.

BACKGROUND: A 23-valent unconjugated pneumococcal polysaccharide vaccine (23vP), routinely administered at the age of 65, has limited effectiveness, and revaccination induces attenuated antibody responses. It is not known whether pneumococcal polysaccharide-protein conjugated vaccines (PCV), although highly effective in infants, offer any immunological advantages over 23vP in adults. METHODS: We immunized adults with schedules combining both PCV and 23vP and investigated B-cell responses to establish whether PCV7 (a 7-valent PCV) induced T-dependent responses in adults, to assess the role of memory B cells in 23vP-induced antibody hyporesponsiveness, and to identify the B-cell subtypes involved. RESULTS: A single dose of PCV7 induced significant increases in serotype-specific memory B-cell populations in peripheral blood indicating a T-dependent response. Conversely, immunization with 23vP resulted in a decrease in memory B-cell frequency. Furthermore, memory B-cell responses to subsequent immunization with PCV7, when given after 23vP, were attenuated. Notably, B1b cells, a subset important in protecting mice against pneumococci, were also depleted following immunization with 23vP in humans. CONCLUSIONS: This study indicates that PCV7 may have an immunological advantage over 23vP in adults and that 23vP-induced depletion of memory and B1b-cell subsets may provide a basis for antibody hyporesponsiveness and the limited effectiveness of 23vP. Clinical Trials Registration. ISRCTN: 78768849.

11ß-HSD1 inhibition in men mitigates prednisolone-induced adverse effects in a proof-of-concept randomised double-blind placebo-controlled trial.

Glucocorticoids prescribed to limit inflammation, have significant adverse effects. As 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) regenerates active glucocorticoid, we investigated whether 11ß-HSD1 inhibition with AZD4017 could mitigate adverse glucocorticoid effects without compromising their anti-inflammatory actions. We conducted a proof-of-concept, randomized, double-blind, placebo-controlled study at Research Unit, Churchill Hospital, Oxford, UK (NCT03111810). 32 healthy male volunteers were randomized to AZD4017 or placebo, alongside prednisolone treatment. Although the primary endpoint of the study (change in glucose disposal during a two-step hyperinsulinemic, normoglycemic clamp) wasn't met, hepatic insulin sensitivity worsened in the placebo-treated but not in the AZD4017-treated group. Protective effects of AZD4017 on markers of lipid metabolism and bone turnover were observed. Night-time blood pressure was higher in the placebo-treated but not in the AZD4017-treated group. Urinary (5aTHF+THF)/THE ratio was lower in the AZD4017-treated but remained the same in the placebo-treated group. Most anti-inflammatory actions of prednisolone persisted with AZD4017 co-treatment. Four adverse events were reported with AZD4017 and no serious adverse events. Here we show that co-administration of AZD4017 with prednisolone in men is a potential strategy to limit adverse glucocorticoid effects.

Screening for Immunodeficiencies in Children With Invasive Pneumococcal Disease: Six-year Experience From a UK Children's Hospital.

BACKGROUND: A previous study showed that investigation of children with invasive pneumococcal disease (IPD) revealed an immunodeficiency in up to 10% of cases. Following this report, we implemented a protocol to investigate children with IPD, to assess the proportion with an immunodeficiency in our setting. METHODS: We retrospectively identified patients who presented with IPD from January 2015 to November 2020 and collected data from medical records. Immunological investigations included complement C3 and C4 levels, classical and alternative pathway complement function, IgG, IgA and IgM levels, specific IgG levels (H. influenza B, tetanus and pneumococcal serotypes), peripheral blood film, lymphocyte subsets, and CD62L-shedding upon activation with Toll-like receptor-agonists in selected cases. RESULTS: We identified a total of 68 children with IPD, with a mortality of 6%. Immunological investigations were performed in 51 children. Four children (8%) had abnormal findings that were deemed of clinical significance. Two children had complement deficiencies (Factor I and C2 deficiency), one child had specific antibody deficiency, and another child had low IgM, low NK-cells and poor persistence of serotype-specific anti-pneumococcal IgG concentrations. Of the 17 children with IPD who were not tested for immunodeficiencies, 4 died and four had possible explanations for the infection. CONCLUSIONS: We identified clinically relevant abnormal immunological findings in 4/51 (8%) of children with IPD. Our results support the recommendation to perform immunological investigations in children with IPD, since this might reveal underlying immunodeficiencies, allowing for necessary preventive measures and close follow-up.

A randomized study comparing combined pneumococcal conjugate and polysaccharide vaccination schedules in adults.

BACKGROUND: The widely used 23-valent plain polysaccharide vaccine (23vP) has limited effectiveness, produces short-lived immune responses, and induces attenuated antibody production after subsequent challenge with pneumococcal vaccines. Our goal was to examine whether priming with the 7-valent pneumococcal conjugate vaccine (PCV7) could enhance the immunogenicity of 23vP for the PCV7 serotypes and to investigate whether 23vP induced hyporesponsiveness could be overcome using PCV7. METHODS: We conducted an open-label randomized study that compared 3 vaccine schedules, each of which consisted of 2 doses of PCV7 and 1 dose of 23vP (23vP-PCV7-PCV7, PCV7-23vP-PCV7, PCV7-PCV7-23vP) administered over a 1-year period in a cohort of 348 adults 50-70 years of age. All vaccines were administered intramuscularly and were given 6 months apart. Blood samples were obtained prior to and 1 month after each vaccination. RESULTS: 23vP administered after priming with 2 doses of PCV7 produced significantly higher antibody concentrations for 3 of the 7 PCV7 serotypes, compared with vaccination with a single dose of 23vP; however, the same immunogenicity could be achieved with a single dose of PCV7. Prior vaccination with 23vP attenuated the antibody response to subsequent PCV7, which was not restored by additional doses of PCV7. CONCLUSION: In adults, vaccination schedules combining PCV7 and 23vP do not provide improved immunogenicity over the use of a single dose of 23vP for most of the serotypes contained in PCV7.

Lessons of the month 2: Meningococcal epiglottitis and connective tissue disease associated with C2 deficiency.

CASE PRESENTATION: A 68-year-old woman was referred for immunological investigation following an episode of meningococcal epiglottitis with associated septicaemia. Several years previously, she had been diagnosed with undifferentiated connective tissue disease. On investigation, alternative pathway complement function was normal; however, classical pathway complement activation was reduced. C1q, C3 and C4 levels were all measured and found to be within their respective normal ranges, but C2 levels were low. Sequencing of the C2 gene was subsequently performed, confirming a diagnosis of type 1 C2 deficiency (C2D). DISCUSSION: C2D is usually hereditary and inherited in an autosomal recessive manner. C2D is often asymptomatic, however, some patients suffer from infections with encapsulated bacteria and/or autoimmune diseases, particularly systemic lupus erythematosus. Recognition of complement pathway deficiency is important due to the predisposition to severe and/or recurrent infections by encapsulated bacteria. Immunisations have the potential to reduce both mortality and morbidity not only for the patient but also for any affected relatives.

Changes in the Rate of Leucine-Rich Glioma-Inactivated 1 Seropositivity During the COVID-19 Lockdown.

This case-control study investigates the positivity rates of the most prevalent neuroglial surface antibodies during the COVID-19 pandemic.

Establishment of a healthy human range for the whole blood 'OX40' assay for the detection of antigen-specific CD4+ T cells by flow cytometry.

Background: Clinical investigation of antigen-specific T cells in potentially immunodeficient patients is an important and often challenging aspect of patient diagnostic work up. Methods for detection of microbial exposure to the T cell compartment exist but are laborious and time consuming. Recently, a whole blood technique involving flow cytometry and detection of CD25 and OX40 (CD134) expression on the surface of activated CD4+ T cells was shown to be accurate and concordant when compared with more traditional methods of antigen-specific T cell detection. Methods: Whole heparinised blood was collected from healthy donors and set up using the 'OX40' assay to detect antigen specific CD4+ T cell responses to Varicella Zoster Virus (VZV), Epstein-Barr Virus (EBV), Cytomegalovirus (CMV), Candida albicans and Streptococcus pneumoniae. Results: The 'OX40' assay technique was clinically validated for routine use in an NHS clinical immunology laboratory by analysis of incubation length (40-50 hours), sample transport time (up to 24 hours at room temperature), concordance with serology testing, proliferation and IFN-γ production. In addition, 63 healthy controls (age range 21-78) were tested for responses to generate a healthy control reference range. Conclusions: The OX40 assay, as presented in this report, represents an economical, rapid, robust whole blood technique to detect antigen-specific T cells which is suitable for clinical immunology diagnostic laboratory use. © 2013 Clinical Cytometry Society.

Establishment of a healthy human range for the whole blood "OX40" assay for the detection of antigen-specific CD4+ T cells by flow cytometry.

BACKGROUND: Clinical investigation of antigen-specific T cells in potentially immunodeficient patients is an important and often challenging aspect of patient diagnostic work up. Methods for detection of microbial exposure to the T-cell compartment exist but are laborious and time consuming. Recently, a whole blood technique involving flow cytometry and detection of CD25 and OX40 (CD134) expression on the surface of activated CD4+ T cells was shown to be accurate and concordant when compared with more traditional methods of antigen-specific T-cell detection. METHODS: Whole heparinized blood was collected from healthy donors and set up using the "OX40" assay to detect antigen-specific CD4+ T-cell responses to Varicella Zoster Virus, Epstein-Barr Virus (EBV), Cytomegalovirus, Candida albicans, and Streptococcus pneumoniae. RESULTS: The "OX40" assay technique was clinically validated for routine use in an NHS clinical immunology laboratory by analysis of incubation length (40-50 h), sample transport time (up to 24 h at room temperature), concordance with serology testing, proliferation and interferon-gamma production. In addition, 63 healthy controls (age range 21-78) were tested for responses to generate a healthy control reference range. CONCLUSIONS: The OX40 assay, as presented in this report, represents an economical, rapid, robust whole blood technique to detect antigen-specific T cells, which is suitable for clinical immunology diagnostic laboratory use.

The zwitterionic type I Streptococcus pneumoniae polysaccharide does not induce memory B cell formation in humans.

In contrast to other pneumococcal serotypes, which are thought to be T-independent antigens, type 1 Streptococcus pneumoniae polysaccharide (Sp1) is a zwitterionic polysaccharide (ZPS). It has previously been shown to be processed and presented by antigen-presenting cells utilizing the MHC-II pathway, which leads to Sp1-induced T cell proliferation, a hallmark of thymus-dependent immune responses. We used peripheral blood mononuclear cells obtained from adults enrolled in a randomised clinical trial to investigate memory B cell responses following immunisation with the 23-valent pneumococcal plain polysaccharide vaccine. Administration of this serotype 1 containing vaccine resulted in the depletion of serotype 1 antigen-specific pre-existing memory B cells compared to baseline. This finding indicates that this ZPS is not processed by a classical TD mechanism within the MHC-II pathway.

Intrauterine growth restriction affects the maturation of myelin.

Intrauterine growth-restriction (IUGR) can lead to adverse neurodevelopmental sequelae in postnatal life. Our objective was to determine whether IUGR, induced by chronic placental insufficiency (CPI) in the guinea pig results in long-term deficits in brain myelination and could therefore contribute to altered neural function. CPI was induced by unilateral ligation of the uterine artery at mid-gestation (term~67 days of gestation; dg), producing growth-restricted (GR) foetuses (60 dg), neonates (1 week) and young adults (8 week); controls were from the unligated horn or sham-operated animals. In GR foetuses (n=8) and neonates (n=7), white matter (WM) volume was reduced (p<0.05); this reduction did not persist in young adults (n=11) however the corpus callosum width was reduced (p<0.05). Immunoreactivity (IR) for myelin basic protein (MBP), myelin-associated glycoprotein (MAG) and myelin proteolipid protein (PLP), all markers of myelinating oligodendrocytes (OL), was reduced in GR foetuses compared to controls. MBP was the most markedly affected with an abnormal retention of protein in the OL soma and a reduction of its incorporation into the myelin sheath. MAG-IR OL density was reduced (p<0.05), while the density of OLs immunoreactive for Olig-2, a transcription factor expressed throughout the entire OL lineage, was increased (p<0.05). MBP-, MAG- and PLP-IR recovered to control levels postnatally. These results suggest that IUGR transiently delays OL maturation and myelination in utero but that myelination and WM volume are restored to control levels postnatally. Long-term deficits in myelination are therefore unlikely to be the major factor underlying the altered neurological function which can be associated with IUGR.

The EUROclass trial: defining subgroups in common variable immunodeficiency.

The heterogeneity of common variable immunodeficiency (CVID) calls for a classification addressing pathogenic mechanisms as well as clinical relevance. This European multicenter trial was initiated to develop a consensus of 2 existing classification schemes based on flowcytometric B-cell phenotyping and the clinical course. The clinical evaluation of 303 patients with the established diagnosis of CVID demonstrated a significant coincidence of granulomatous disease, autoimmune cytopenia, and splenomegaly. Phenotyping of B-cell subpopulations confirmed a severe reduction of switched memory B cells in most of the patients that was associated with a higher risk for splenomegaly and granulomatous disease. An expansion of CD21(low) B cells marked patients with splenomegaly. Lymphadenopathy was significantly linked with transitional B-cell expansion. Based on these findings and pathogenic consideration of B-cell differentiation, we suggest an improved classification for CVID (EUROclass), separating patients with nearly absent B cells (less than 1%), severely reduced switched memory B cells (less than 2%), and expansion of transitional (more than 9%) or CD21(low) B cells (more than 10%). Whereas the first group contains all patients with severe defects of early B-cell differentiation, severely reduced switched memory B cells indicate a defective germinal center development as found in inducible constimulator (ICOS) or CD40L deficiency. The underlying defects of expanded transitional or CD21(low) B cells remain to be elucidated. This trial is re-gistered at http://www.uniklinik-freiburg.de/zks/live/uklregister/Oeffentlich.html as UKF000308.

Bacterial superantigen facilitates epithelial presentation of allergen to T helper 2 cells.

Although clinical and laboratory evidence support roles for both staphylococcal infection and environmental allergens in the pathogenesis of atopic dermatitis, human studies have largely considered these variables independently. We sought to test the hypothesis that staphylococcal superantigen influences the allergen-specific T cell response. We first mapped a Der p 1 epitope and used HLA DRB1*1501 class II tetramer-based cell sorted populations to show that specific CD4(+) T cells were able to recognize the peptide presented by HLA DR-matched keratinocytes. We observed that staphylococcal enterotoxin B (SEB) enhanced the IL-4 Der p 1-specific T cell response. This response was mediated by two synergistic mechanisms: first, SEB-induced IFN-gamma promoted class II and intercellular adhesion molecule-1 expression by presenting keratinocytes; and second, SEB-induced IL-4 directly amplified allergen-specific CD4(+) T cell production of many cytokines. We propose that handling of staphylococcal infection is a critical step in the amplification of the allergen-specific T cell response, linking two common disease associations and with implications for the prevention and treatment of atopic disease.

Minimally invasive anterior thoracotomy for routine lung cancer resection.

OBJECTIVES: : A 7-year experience with a minimally invasive approach to routine lung cancer resection is compared with standard lateral open thoracotomy. METHODS: : All patients undergoing lung resection with curative intent for primary lung cancer between July 1998 and November 2005 by a single surgical team were registered. Surgical access was obtained through a mini 5- to 6-cm anterior thoracotomy with video assistance; direct visualization was also used extensively. RESULTS: : Patients (n = 167) underwent major pulmonary resection for primary lung cancer. The minimally invasive group (MI), 137 patients, included 12 fully endoscopic or robotic approaches. The open lateral (OL) approach included 30 patients (18%). Both groups included pneumonectomies (8 MI, 3 OL), sleeve resections (3 MI, 2 OL), chest wall resections (2 MI, 5 OL), and pancoasts (3 MI, 0 OL) and had full lymph node resections. The Kaplan-Meier estimated overall mean survival was 64.5 months (95% CL, 58 to 71 months). Mean estimate survivals were stage 1a, 66%; stage 1b, 65%; stage 2a, 61%; stage 2b, 55%; stage 3a, 52%; stage 3b, 45%. Mean survival in the MI group was 64.3 months versus 59.3 with standard open access (OL) (Χ = 0.003 Mantel-Cox; significance, 0.959). In-hospital mortality rate was 2.2%; conversion from a mini to open procedure was 1.5%. Avoidance of rib spreading (soft tissue retractor) and small incisions appeared to have reduced pain and improved early recovery. CONCLUSIONS: : Kaplan-Meier survival for routine unselected lung cancer resection through a minimal access approach was not significantly different from the open approach and reflects published survival curves.

Persistent central memory phenotype of circulating Fel d 1 peptide/DRB1*0101 tetramer-binding CD4+ T cells.

BACKGROUND: Although substantial evidence suggests that T cells are important in the pathogenesis of atopic dermatitis (AD), little is known of the differentiation status of CD4+ T cells specific for common environmental allergens. OBJECTIVE: To determine the frequency, differentiation phenotype, and function of circulating allergen-specific CD4+ T cells in adult individuals with severe persistent AD and controls. METHODS: Using tetrameric complexes of an HLA DRB1*0101 restricted epitope from Fel d 1, the major IgE-reactive component of cat dander, we studied ex vivo and cultured T-cell frequency and phenotype in individuals with AD and healthy controls. Cytokine secretion was measured by ex vivo and cultured IFN-gamma, IL-4, and IL-10 enzyme linked immuno-spot analysis. RESULTS: Ex vivo Fel d 1-specific DRB1*0101-restricted CD4+ T cells express high levels of CCR7, CD62L, CD27, and CD28 and proportionately low levels of tissue-specific homing receptors and TH1 and TH2 cytokine production, placing the cells largely within the central memory subgroup. CONCLUSION: Circulating Fel d 1-specific DRB1*0101-restricted CD4+ T cells maintain central memory capacity, consistent with a potential to contribute to persisting clinical atopic disease. CLINICAL IMPLICATIONS: Persisting central memory characteristics of allergen-specific CD4+ T cells in individuals with AD may contribute to chronic disease.