Phenotype and oxidative burst of low-density neutrophil subpopulations are altered in common variable immunodeficiency patients

Common variable immunodeficiency disorder (CVID) is the most common form of primary antibody immunodeficiency. Due to low antibody levels, CVID patients receive intravenous or subcutaneous immunoglobulin replacement therapy as treatment. CVID is associated with the chronic activation of granulocytes, including an increased percentage of low-density neutrophils (LDNs). In this study, we examined changes in the percentage of LDNs and the expression of their surface markers in 25 patients with CVID and 27 healthy donors (HD) after in vitro stimulation of whole blood using IVIg. An oxidative burst assay was used to assess the functionality of LDNs. CVID patients had increased both relative and absolute LDN counts with a higher proportion of mLDNs compared to iLDNs, distinguished based on the expression of CD10 and CD16. Immature LDNs in the CVID and HD groups had significantly reduced oxidative burst capacity compared to mature LDNs. Interestingly we observed reduced oxidative burst capacity, reduced expression of CD10 after stimulation of WB, and higher expression of PD-L1 in mature LDNs in CVID patients compared to HD cells. Our data indicate that that the functional characteristics of LDNs are closely linked to their developmental stage. The observed reduction in oxidative burst capacity in mLDNs in CVID patients could contribute to an increased susceptibility to recurrent bacterial infections among CVID patients.

Systematic Approach Revealed SERPING1 Splicing-Affecting Variants to be Highly Represented in the Czech National HAE Cohort

Hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE) is a rare and life-threatening condition characterized by recurrent localized edema. We conducted a systematic screening of SERPING1 defects in a cohort of 207 Czech patients from 85 families with C1-INH-HAE. Our workflow involved a combined strategy of sequencing extended to UTR and deep intronic regions, advanced in silico prediction tools, and mRNA-based functional assays. This approach allowed us to detect a causal variant in all families except one and to identify a total of 56 different variants, including 5 novel variants that are likely to be causal. We further investigated the functional impact of two splicing variants, namely c.550 + 3A > C and c.686-7C > G using minigene assays and RT-PCR mRNA analysis. Notably, our cohort showed a considerably higher proportion of detected splicing variants compared to other central European populations and the LOVD database. Moreover, our findings revealed a significant association between HAE type 1 missense variants and a delayed HAE onset when compared to null variants. We also observed a significant correlation between the presence of the SERPING1 variant c.-21 T > C in the trans position to causal variants and the frequency of attacks per year, disease onset, as well as Clinical severity score. Overall, our study provides new insights into the genetic landscape of C1-INH-HAE in the Czech population, including the identification of novel variants and a better understanding of genotype-phenotype correlations. Our findings also highlight the importance of comprehensive screening strategies and functional analyses in improving the C1-INH-HAE diagnosis and management.

Intraoral and maxillofacial abnormalities in patients with autosomal dominant hyper-IgE syndrome

Autosomal dominant hyper-IgE syndrome (AD-HIES) is an inborn error of immunity (IEI) caused by a dominant-negative mutation in the signal transducer and activator of transcription 3 (STAT 3). This disease is characterized by chronic eczematoid dermatitis, recurrent staphylococcal skin abscesses, pneumonia, pneumatoceles, and extremely high serum IgE levels. Loss-of-function STAT3 mutations may also result in distinct non-immunologic features such as dental, facial, skeletal, and vascular abnormalities, central nervous system malformations and an increased risk for bone fractures. Prophylactic treatment of Candida infections and prophylactic antimicrobial therapy for staphylococcal skin infections and sinopulmonary infections are essential. An awareness of the oral and maxillofacial features of HIES may facilitate early diagnosis with genetic counselling and may improve future patient care. This study describes oral, dental, and maxillofacial manifestations in 14 patients with genetically defined AD-HIES. We also review the literature and propose recommendations for the complex care of patients with this rare primary immunodeficiency.

Corrigendum: Do common infections trigger disease-onset or -severity in CTLA-4 insufficiency?

[This corrects the article DOI: 10.3389/fimmu.2022.1011646.].

Do common infections trigger disease-onset or -severity in CTLA-4 insufficiency?

PURPOSE

Heterozygous mutations in CTLA4 lead to an inborn error of immunity characterized by immune dysregulation and immunodeficiency, known as CTLA-4 insufficiency. Cohort studies on CTLA4 mutation carriers showed a reduced penetrance (around 70%) and variable disease expressivity, suggesting the presence of modifying factors. It is well studied that infections can trigger autoimmunity in humans, especially in combination with a genetic predisposition.

METHODS

To investigate whether specific infections or the presence of specific persisting pathogens are associated with disease onset or severity in CTLA-4 insufficiency, we have examined the humoral immune response in 13 CTLA4 mutation carriers, seven without clinical manifestation and six with autoimmune manifestations, but without immunoglobulin replacement therapy against cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus 1/2 (HSV 1/2), parvovirus B19 and Toxoplasma gondii. Additionally, we have measured FcγRIII/CD16A activation by EBV-specific IgG antibodies to examine the functional capabilities of immunoglobulins produced by CTLA4 mutation carriers.

RESULTS

The seroprevalence between affected and unaffected CTLA4 mutation carriers did not differ significantly for the examined pathogens. Additionally, we show here that CTLA4 mutation carriers produce EBV-specific IgG, which are unimpaired in activating FcγRIII/CD16A.

CONCLUSIONS

Our results show that the investigated pathogens are very unlikely to trigger the disease onset in CTLA-4-insufficient individuals, and their prevalence is not correlated with disease severity or expressivity.

Risk Factors for Severe COVID-19 and Hospital Admission in Patients With Inborn Errors of Immunity - Results From a Multicenter Nationwide Study

Despite the progress in the understanding how COVID-19 infection may impact immunocompromised patients, the data on inborn errors of immunity (IEI) remain limited and ambiguous. Therefore, we examined the risk of severe infection course and hospital admission in a large cohort of patients with IEI. In this multicenter nationwide retrospective survey-based trial, the demographic, clinical, and laboratory data were collected by investigating physicians from 8 national referral centers for the diagnosis and treatment of IEI using a COVID-19-IEI clinical questionnaire. In total, 81 patients with IEI (including 16 with hereditary angioedema, HAE) and confirmed SARS-CoV-2 infection were enrolled, and were found to have a 2.3-times increased (95%CI: 1.44–3.53) risk ratio for hospital admission and a higher mortality ratio (2.4% vs. 1.7% in the general population). COVID-19 severity was associated with the presence of clinically relevant comorbidities, lymphopenia, and hypogammaglobulinemia, but not with age or BMI. No individuals with HAE developed severe disease, despite a hypothesized increased risk due to perturbed bradykinin metabolism. We also demonstrated a high seroconversion rate in antibody-deficient patients and the safety of anti-spike SARS CoV-2 monoclonal antibodies and convalescent plasma. Thus, IEI except for HAE, represent significant risk factors for a severe COVID-19. Therefore, apart from general risk factors, immune system dysregulation may also be involved in the poor outcomes of COVID-19. Despite the study limitations, our results support the findings from previously published trials.

Therapeutic options for CTLA-4 insufficiency

BACKGROUND

Heterozygous germline mutations in cytotoxic T lymphocyte-associated antigen-4 (CTLA4) impair the immunomodulatory function of regulatory T cells. Affected individuals are prone to life-threatening autoimmune and lymphoproliferative complications. A number of therapeutic options are currently being used with variable effectiveness.

OBJECTIVE

Our aim was to characterize the responsiveness of patients with CTLA-4 insufficiency to specific therapies and provide recommendations for the diagnostic workup and therapy at an organ-specific level.

METHODS

Clinical features, laboratory findings, and response to treatment were reviewed retrospectively in an international cohort of 173 carriers of CTLA4 mutation. Patients were followed between 2014 and 2020 for a total of 2624 months from diagnosis. Clinical manifestations were grouped on the basis of organ-specific involvement. Medication use and response were recorded and evaluated.

RESULTS

Among the 173 CTLA4 mutation carriers, 123 (71%) had been treated for immune complications. Abatacept, rituximab, sirolimus, and corticosteroids ameliorated disease severity, especially in cases of cytopenias and lymphocytic organ infiltration of the gut, lungs, and central nervous system. Immunoglobulin replacement was effective in prevention of infection. Only 4 of 16 patients (25%) with cytopenia who underwent splenectomy had a sustained clinical response. Cure was achieved with stem cell transplantation in 13 of 18 patients (72%). As a result of the aforementioned methods, organ-specific treatment pathways were developed.

CONCLUSION

Systemic immunosuppressants and abatacept may provide partial control but require ongoing administration. Allogeneic hematopoietic stem cell transplantation offers a possible cure for patients with CTLA-4 insufficiency.

Possibilities for the analysis of peripheral blood B cell subpopulations in a routine immunological laboratory

B cells play a vital role in the defence of the body against infectious agents. Apart from their ability to present antigen to T cells, B cells are mainly producers of antibodies. These play a crucial role in the effective elimination of infection and are also involved in the regulation of the immune response. The analysis of peripheral blood B cell subpopulations that makes it possible to monitor the development of B cells to the stage of antibody producing plasmablasts provides a valuable laboratory parameter which is important for both the study of the pathogenesis and diagnosis of some diseases. Laboratory analysis of B cell subpopulations is now a routinely available laboratory option thanks to the development of multicolour flow cytometry. This article summarizes the core knowledge which is currently applied to the analysis of B cell subpopulations in immunological laboratories.

Neurological manifestation of immune system dysregulation resulting from CTLA-4 receptor mutation: a case report

This contribution reports the case of a young female patient with a cytotoxic T-lymphocyte antigen 4 (CTLA-4) heterozygous missense mutation giving rise to a broad range of autoimmune diseases, including central nervous system inflammation presenting as disseminated intramedullary and infiltrating brain lesions on MRI. Multiple sclerosis was one of the diagnoses considered. CTLA-4 is a negative immune regulator essential for the function of regulatory T-cells, themselves responsible for maintaining self-tolerance and immune homeostasis. Heterozygous germline mutations in CTLA-4 may lead to an autosomal dominant immune dysregulation syndrome with highly variable phenotype, including various immunodeficiency and autoimmune diseases, along with neurological manifestations.

European Society for Immunodeficiencies (ESID) and European Reference Network on Rare Primary Immunodeficiency, Autoinflammatory and Autoimmune Diseases (ERN RITA) Complement Guideline: Deficiencies, Diagnosis, and Management

This guideline aims to describe the complement system and the functions of the constituent pathways, with particular focus on primary immunodeficiencies (PIDs) and their diagnosis and management. The complement system is a crucial part of the innate immune system, with multiple membrane-bound and soluble components. There are three distinct enzymatic cascade pathways within the complement system, the classical, alternative and lectin pathways, which converge with the cleavage of central C3. Complement deficiencies account for ~5% of PIDs. The clinical consequences of inherited defects in the complement system are protean and include increased susceptibility to infection, autoimmune diseases (e.g., systemic lupus erythematosus), age-related macular degeneration, renal disorders (e.g., atypical hemolytic uremic syndrome) and angioedema. Modern complement analysis allows an in-depth insight into the functional and molecular basis of nearly all complement deficiencies. However, therapeutic options remain relatively limited for the majority of complement deficiencies with the exception of hereditary angioedema and inhibition of an overactivated complement system in regulation defects. Current management strategies for complement disorders associated with infection include education, family testing, vaccinations, antibiotics and emergency planning.

Czech Hizentra Noninterventional Study With Rapid Push: Efficacy, Safety, Tolerability, and Convenience of Therapy With 20% Subcutaneous Immunoglobulin

PURPOSE

Immunoglobulin substitution therapy is an essential therapeutic approach for patients with primary antibody deficiencies. Different methods of administration, including intravenous immunoglobulin (IVIG) or subcutaneous immunoglobulin (SCIG) preparations, provide effective and tolerable treatment and enable the adjustment of therapy to patients' needs. A new 20% SCIG represents a new therapeutic option and a new route of administration using rapid-push application. The aim of the Czech Hizentra Noninterventional Study With Rapid Push (CHHINSTRAP) is to evaluate patient satisfaction with as well as the tolerability and efficacy of nonmedical switch to 20% SCIG from previous treatment with IVIG or SCIG and rapid push as a new way to administer SCIG. CHHINSTRAP is the first Phase IV, noninterventional, open-label, prospective, multicentric study of this type conducted in Central and Eastern Europe.

METHODS

Primary end points, including efficacy, adverse effects, convenience of use, and overall satisfaction, were evaluated by Treatment Satisfaction Questionnaire for Medication version II. Secondary end points, such as serum IgG trough levels, infusion duration, number of application sites, frequency of infections, related hospital admissions, and antibiotic consumption, were obtained from patients at each follow-up visit.

FINDINGS

Together, 50 eligible patients with primary antibody deficiency were switched from SCIG or IVIG to an equivalent dose of 20% SCIG and were followed up for 12 months during 5 consecutive visits. The results indicate that patients switched from previous IVIG or SCIG preparations had significantly higher serum trough IgG levels and a lower incidence of infections and related events, such as hospital admissions or consumption of antibiotics. These findings were also reflected in gradually increasing convenience of use and overall satisfaction reported by patients. Apart from duration of application, no differences were found between patients previously receiving SCIG or IVIG. Moreover, our study found a high level of safety of 20% SCIG rapid push, which was comparable to other preparations and application methods.

IMPLICATIONS

On the basis of the results of CHHINSTRAP study, we conclude that 20% SCIG is a tolerable and effective immunoglobulin preparation, representing a new therapeutic approach in patients with primary antibody deficiencies. Its efficacy and tolerability have been found in patients on nonmedical switch from previous treatment with IVIG or SCIG.

Novel SAMD9 Mutation in a Patient With Immunodeficiency, Neutropenia, Impaired Anti-CMV Response, and Severe Gastrointestinal Involvement

Mutations in the Sterile alpha motif domain containing 9 (SAMD9) gene have been described in patients with severe multisystem disorder, MIRAGE syndrome, but also in patients with bone marrow (BM) failure in the absence of other systemic symptoms. The role of hematopoietic stem cell transplantation (HSCT) in the management of the disease is still unclear. Here, we present a patient with a novel mutation in SAMD9 (c.2471 G>A, p.R824Q), manifesting with prominent gastrointestinal tract involvement and immunodeficiency, but without any sign of adrenal insufficiency typical for MIRAGE syndrome. He suffered from severe CMV (cytomegalovirus) infection at 3 months of age, with a delayed development of T lymphocyte functional response against CMV, profound T cell activation, significantly reduced B lymphocyte counts and impaired lymphocyte proliferative response. Cultured T cells displayed slightly lower calcium flux and decreased survival. At the age of 6 months, he developed severe neutropenia requiring G-CSF administration, and despite only mild morphological and immunophenotypical disturbances in the BM, 78% of the BM cells showed monosomy 7 at the age of 18 months. Surprisingly, T cell proliferation after CD3 stimulation and apoptosis of the cells normalized during the follow-up, possibly reflecting the gradual development of monosomy 7. Among other prominent symptoms, he had difficulty swallowing, requiring percutaneous endoscopic gastrostomy (PEG), frequent gastrointestinal infections, and perianal erosions. He suffered from repeated infections and periodic recurring fevers with the elevation of inflammatory markers. At 26 months of age, he underwent HSCT that significantly improved hematological and immunological laboratory parameters. Nevertheless, he continued to suffer from other conditions, and subsequently, he died at day 440 post-transplant due to sepsis. Pathogenicity of this novel SAMD9 mutation was confirmed experimentally. Expression of mutant SAMD9 caused a significant decrease in proliferation and increase in cell death of the transfected cells.

Conclusion: We describe a novel SAMD9 mutation in a patient with prominent gastrointestinal and immunological symptoms but without adrenal hypoplasia. Thus, SAMD9 mutations should be considered as cause of enteropathy in pediatric patients. The insufficient therapeutic outcome of transplantation further questions the role of HSCT in the management of patients with SAMD9 mutations and multisystem involvement.

Correction to: Imaging of Bronchial Pathology in Antibody Deficiency: Data from the European Chest CT Group

In the original version of this article unfortunately two authors were missing: Dr. Jürgen Weidemann and Dr. Daniel Berthold. The correct list of authors is presented above.

CVID-Associated Tumors: Czech Nationwide Study Focused on Epidemiology, Immunology, and Genetic Background in a Cohort of Patients With CVID

Background: Common variable immunodeficiency disorder (CVID) is one of the most frequent inborn errors of immunity, increased occurrence of malignancies, particularly lymphomas, and gastric cancers, has long been noted among CVID patients. Multifactorial etiology, including immune dysregulation, infections, chronic inflammation, or genetic background, is suggested to contribute to tumor development. Here, we present the results of the first Czech nationwide study focused on epidemiology, immunology and genetic background in a cohort of CVID patients who also developed tumors

Methods: The cohort consisted of 295 CVID patients followed for 3,070 patient/years. Standardized incidence ratio (SIR) was calculated to determine the risk of cancer, and Risk ratio (RR) was established to evaluate the significance of comorbidities. Moreover, immunophenotyping, including immunoglobulin levels and lymphocyte populations, was assessed. Finally, Whole exome sequencing (WES) was performed in all patients with lymphoma to investigate the genetic background.

Results: Twenty-five malignancies were diagnosed in 22 patients in a cohort of 295 CVID patients. SIR was more than 6 times greater in comparison to the general population. The most common neoplasias were gastric cancers and lymphomas. History of Immune thrombocytopenic purpura (ITP) was established as a potential risk factor, with over 3 times higher risk of cancer development. The B cell count at diagnosis of lymphoma was reduced in the lymphoma group; moreover, post-treatment B and T cell lymphopenia, associated with poorer outcome, was found in a majority of the patients. Intriguingly, no NK cell depression was observed after the chemotherapy. WES revealed heterogeneous genetic background among CVID patients with tumors, identifying gene variants associated with primary immunodeficiencies (such as CTLA4, PIK3CD, PMS2) and/or increased cancer susceptibility (including BRCA1, RABEP1, EP300, KDM5A).

Conclusions: The incidence of malignancy in our CVID cohort was found to be more than 6 times greater compared to the general population. Gastric cancers and lymphomas were the most frequently diagnosed tumors. ITP was identified as a risk factor for malignancy in CVID patients. WES analysis confirmed a wide genetic heterogeneity among CVID patients. The identified causative or modifying gene variants pointed to errors in mechanisms contributing to both immunodeficiency and malignancy.

Imaging of Bronchial Pathology in Antibody Deficiency: Data from the European Chest CT Group

Studies of chest computed tomography (CT) in patients with primary antibody deficiency syndromes (ADS) suggest a broad range of bronchial pathology. However, there are as yet no multicentre studies to assess the variety of bronchial pathology in this patient group. One of the underlying reasons is the lack of a consensus methodology, a prerequisite to jointly document chest CT findings. We aimed to establish an international platform for the evaluation of bronchial pathology as assessed by chest CT and to describe the range of bronchial pathologies in patients with antibody deficiency. Ffteen immunodeficiency centres from 9 countries evaluated chest CT scans of patients with ADS using a predefined list of potential findings including an extent score for bronchiectasis. Data of 282 patients with ADS were collected. Patients with common variable immunodeficiency disorders (CVID) comprised the largest subgroup (232 patients, 82.3%). Eighty percent of CVID patients had radiological evidence of bronchial pathology including bronchiectasis in 61%, bronchial wall thickening in 44% and mucus plugging in 29%. Bronchiectasis was detected in 44% of CVID patients aged less than 20 years. Cough was a better predictor for bronchiectasis than spirometry values. Delay of diagnosis as well as duration of disease correlated positively with presence of bronchiectasis. The use of consensus diagnostic criteria and a pre-defined list of bronchial pathologies allows for comparison of chest CT data in multicentre studies. Our data suggest a high prevalence of bronchial pathology in CVID due to late diagnosis or duration of disease.

Phenotype, penetrance, and treatment of 133 cytotoxic T-lymphocyte antigen 4-insufficient subjects

BACKGROUND

Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is a negative immune regulator. Heterozygous CTLA4 germline mutations can cause a complex immune dysregulation syndrome in human subjects.

OBJECTIVE

We sought to characterize the penetrance, clinical features, and best treatment options in 133 CTLA4 mutation carriers.

METHODS

Genetics, clinical features, laboratory values, and outcomes of treatment options were assessed in a worldwide cohort of CTLA4 mutation carriers.

RESULTS

We identified 133 subjects from 54 unrelated families carrying 45 different heterozygous CTLA4 mutations, including 28 previously undescribed mutations. Ninety mutation carriers were considered affected, suggesting a clinical penetrance of at least 67%; median age of onset was 11 years, and the mortality rate within affected mutation carriers was 16% (n = 15). Main clinical manifestations included hypogammaglobulinemia (84%), lymphoproliferation (73%), autoimmune cytopenia (62%), and respiratory (68%), gastrointestinal (59%), or neurological features (29%). Eight affected mutation carriers had lymphoma, and 3 had gastric cancer. An EBV association was found in 6 patients with malignancies. CTLA4 mutations were associated with lymphopenia and decreased T-, B-, and natural killer (NK) cell counts. Successful targeted therapies included application of CTLA-4 fusion proteins, mechanistic target of rapamycin inhibitors, and hematopoietic stem cell transplantation. EBV reactivation occurred in 2 affected mutation carriers after immunosuppression.

CONCLUSIONS

Affected mutation carriers with CTLA-4 insufficiency can present in any medical specialty. Family members should be counseled because disease manifestation can occur as late as 50 years of age. EBV- and cytomegalovirus-associated complications must be closely monitored. Treatment interventions should be coordinated in clinical trials.

Neutrophil and Granulocytic Myeloid-Derived Suppressor Cell-Mediated T Cell Suppression Significantly Contributes to Immune Dysregulation in Common Variable Immunodeficiency Disorders

Common variable immunodeficiency disorders (CVID) represent a group of primary immunodeficiency diseases characterized by hypogammaglobulinemia and impaired specific Ab response, resulting in recurrent infections due to dysfunctional immune response. The specific mechanisms mediating immune deficiency in CVID remain to be determined. Previous studies indicated that immune dysregulation in CVID patients is associated with chronic microbial translocation, systemic immune activation, and altered homeostasis of lymphocytic and myeloid lineages. A detailed phenotypic, functional characterization of plasma markers and immune cell populations was performed in 46 CVID patients and 44 healthy donors. CVID patients displayed significantly elevated plasma levels of a marker of neutrophil activation neutrophil gelatinase-associated lipocalin. Neutrophils from CVID patients exhibited elevated surface levels of CD11b and PD-L1 and decreased levels of CD62L, CD16, and CD80, consistent with a phenotype of activated neutrophils with suppressive properties. Neutrophils from CVID patients actively suppressed T cell activation and release of IFN-γ via the production of reactive oxygen species. Furthermore, CVID was associated with an increased frequency of low-density neutrophils (LDNs)/granulocytic myeloid-derived suppressor cells. LDN/granulocytic myeloid-derived suppressor cell frequency in CVID patients correlated with reduced T cell responsiveness. Exogenous stimulation of whole blood with bacterial LPS emulated some but not all of the phenotypic changes observed on neutrophils from CVID patients and induced neutrophil population with LDN phenotype. The presented data demonstrate that neutrophils in the blood of CVID patients acquire an activated phenotype and exert potent T cell suppressive activity. Specific targeting of myeloid cell-derived suppressor activity represents a novel potential therapeutic strategy for CVID.

Hyper-IgE in the allergy clinic--when is it primary immunodeficiency?

The 2017 International Union of Immunological Societies (IUIS) classification recognizes 3 hyper-IgE syndromes (HIES), including the prototypic Job's syndrome (autosomal dominant STAT3-loss of function) and autosomal recessive PGM3 and SPINK5 syndromes. Early diagnosis of PID can direct life-saving or transformational interventions; however, it remains challenging owing to the rarity of these conditions. This can result in diagnostic delay and worsen prognosis. Within increasing access to "clinical-exome" testing, clinicians need to be aware of the implication and rationale for genetic testing, including the benefits and limitations of current therapies. Extreme elevation of serum IgE has been associated with a growing number of PID syndromes including the novel CARD11 and ZNF341 deficiencies. Variable elevations in IgE are associated with defects in innate, humoral, cellular and combined immunodeficiency syndromes. Barrier compromise can closely phenocopy these conditions. The aim of this article was to update readers on recent developments at this important interface between allergy and immunodeficiency, highlighting key clinical scenarios which should draw attention to possible immunodeficiency associated with extreme elevation of IgE, and outline initial laboratory assessment and management.

CEBPE-Mutant Specific Granule Deficiency Correlates With Aberrant Granule Organization and Substantial Proteome Alterations in Neutrophils

Specific granule deficiency (SGD) is a rare disorder characterized by abnormal neutrophils evidenced by reduced granules, absence of granule proteins, and atypical bilobed nuclei. Mutations in CCAAT/enhancer-binding protein-ε (CEBPE) are one molecular etiology of the disease. Although C/EBPε has been studied extensively, the impact of CEBPE mutations on neutrophil biology remains elusive. Here, we identified two SGD patients bearing a previously described heterozygous mutation (p.Val218Ala) in CEBPE. We took this rare opportunity to characterize SGD neutrophils in terms of granule distribution and protein content. Granules of patient neutrophils were clustered and polarized, suggesting that not only absence of specific granules but also defects affecting other granules contribute to the phenotype. Our analysis showed that remaining granules displayed mixed protein content and lacked several glycoepitopes. To further elucidate the impact of mutant CEBPE, we performed detailed proteomic analysis of SGD neutrophils. Beside an absence of several granule proteins in patient cells, we observed increased expression of members of the linker of nucleoskeleton and cytoskeleton complex (nesprin-2, vimentin, and lamin-B2), which control nuclear shape. This suggests that absence of these proteins in healthy individuals might be responsible for segmented shapes of neutrophilic nuclei. We further show that the heterozygous mutation p.Val218Ala in CEBPE causes SGD through prevention of nuclear localization of the protein product. In conclusion, we uncover that absence of nuclear C/EBPε impacts on spatiotemporal expression and subsequent distribution of several granule proteins and further on expression of proteins controlling nuclear shape.

Selective IgM Deficiency: Clinical and Laboratory Features of 17 Patients and a Review of the Literature

PURPOSE

Primary selective IgM deficiency (sIgMD) is a primary immunodeficiency with unclear pathogenesis and a low number of published cases.

METHODS

We reviewed clinical and laboratory manifestations of 17 sIgMD patients. Serum IgM, IgG, and its subclasses, IgA, IgE, antibodies against tetanus toxoid, pneumococcal polysaccharides and Haemophilus influenzae type b, isohemagglutinins, and T and B lymphocyte subsets, expressions of IgM on B cells and B lymphocyte production of IgM were compared with previously reported case reports and a small series of patients, which included 81 subjects in total.

RESULTS

We found that some patients in our cohort (OC) and published cases (PC) had increased IgE levels (OC 7/15; PC 21/37), decreased IgG4 levels (OC 5/14), very low titers of isohemagglutinins (OC 8/8; PC 18/21), increased transitional B cell counts (OC 8/9), decreased marginal zone B cell counts (OC 8/9), and increased 21^low B cell counts (OC 7/9). Compared with the PC (20/20), only two of five OC patients showed very low or undetectable production of IgM after stimulation. A majority of the patients had normal antibody production to protein and polysaccharide antigens, basic lymphocyte subset counts, and expression of surface IgM molecules on B cells.

CONCLUSIONS

Low IgM levels are associated with various immunopathological disorders; however, pathogenic mechanisms leading to decreased IgM serum level in selective IgM deficiency remain unclear. Moreover, it is difficult to elucidate how strong these associations are and if these immunopathological conditions are primary or secondary.

When to initiate immunoglobulin replacement therapy (IGRT) in antibody deficiency: a practical approach

Primary antibody deficiencies (PAD) constitute the majority of all primary immunodeficiency diseases (PID) and immunoglobulin replacement forms the mainstay of therapy for many patients in this category. Secondary antibody deficiencies (SAD) represent a larger and expanding number of patients resulting from the use of a wide range of immunosuppressive therapies, in particular those targeting B cells, and may also result from renal or gastrointestinal immunoglobulin losses. While there are clear similarities between primary and secondary antibody deficiencies, there are also significant differences. This review describes a practical approach to the clinical, laboratory and radiological assessment of patients with antibody deficiency, focusing on the factors that determine whether or not immunoglobulin replacement should be used. The decision to treat is more straightforward when defined diagnostic criteria for some of the major PADs, such as common variable immunodeficiency disorders (CVID) or X-linked agammaglobulinaemia (XLA), are fulfilled or, indeed, when there is a very low level of immunoglobulin production in association with an increased frequency of severe or recurrent infections in SAD. However, the presentation of many patients is less clear-cut and represents a considerable challenge in terms of the decision whether or not to treat and the best way in which to assess the outcome of therapy. This decision is important, not least to improve individual quality of life and reduce the morbidity and mortality associated with recurrent infections but also to avoid inappropriate exposure to blood products and to ensure that immunoglobulin, a costly and limited resource, is used to maximal benefit.

Secondary Combined Immunodeficiency in Pediatric Patients after the Fontan Operation: Three Case Reports

The Fontan operation or total cavopulmonal connection (TCPC) is a palliative surgical correction of rare and complex inborn cardiac malformations that are characterized by univentricular circulation. Protein-losing enteropathy (PLE) develops in 4-13% of patients after the Fontan procedure. Fontan-related PLE leads to secondary combined immunodeficiency marked by hypogammaglobulinemia and predominantly CD4+ lymphocytopenia. Here, we present 3 case reports of patients with secondary immunodeficiency after the Fontan operation. The severity of hypogammaglobulinemia correlated with the nature of the infectious complications; however, clinical manifestations of T cell deficiency such as severe viral or opportunistic infections were not observed. The clinical consequences of the secondary combined immunodeficiency were modified by immunoglobulin replacement treatment and antibiotic prophylaxis. Heart transplantation led to the resolution of PLE signs and the restitution of IgG levels in 1 transplanted patient. Our experience shows that the immunological follow-up was delayed in all 3 patients. We suggest that all patients should be followed regularly by a clinical immunologist after the Fontan surgery.

Long-term outcomes of 176 patients with X-linked hyper-IgM syndrome treated with or without hematopoietic cell transplantation

BACKGROUND

X-linked hyper-IgM syndrome (XHIGM) is a primary immunodeficiency with high morbidity and mortality compared with those seen in healthy subjects. Hematopoietic cell transplantation (HCT) has been considered a curative therapy, but the procedure has inherent complications and might not be available for all patients.

OBJECTIVES

We sought to collect data on the clinical presentation, treatment, and follow-up of a large sample of patients with XHIGM to (1) compare long-term overall survival and general well-being of patients treated with or without HCT along with clinical factors associated with mortality and (2) summarize clinical practice and risk factors in the subgroup of patients treated with HCT.

METHODS

Physicians caring for patients with primary immunodeficiency diseases were identified through the Jeffrey Modell Foundation, United States Immunodeficiency Network, Latin American Society for Immunodeficiency, and Primary Immune Deficiency Treatment Consortium. Data were collected with a Research Electronic Data Capture Web application. Survival from time of diagnosis or transplantation was estimated by using the Kaplan-Meier method compared with log-rank tests and modeled by using proportional hazards regression.

RESULTS

Twenty-eight clinical sites provided data on 189 patients given a diagnosis of XHIGM between 1964 and 2013; 176 had valid follow-up and vital status information. Sixty-seven (38%) patients received HCT. The average follow-up time was 8.5 ± 7.2 years (range, 0.1-36.2 years). No difference in overall survival was observed between patients treated with or without HCT (P = .671). However, risk associated with HCT decreased for diagnosis years 1987-1995; the hazard ratio was significantly less than 1 for diagnosis years 1995-1999. Liver disease was a significant predictor of overall survival (hazard ratio, 4.9; 95% confidence limits, 2.2-10.8; P < .001). Among survivors, those treated with HCT had higher median Karnofsky/Lansky scores than those treated without HCT (P < .001). Among patients receiving HCT, 27 (40%) had graft-versus-host disease, and most deaths occurred within 1 year of transplantation.

CONCLUSION

No difference in survival was observed between patients treated with or without HCT across all diagnosis years (1964-2013). However, survivors treated with HCT experienced somewhat greater well-being, and hazards associated with HCT decreased, reaching levels of significantly less risk in the late 1990s. Among patients treated with HCT, treatment at an early age is associated with improved survival. Optimism remains guarded as additional evidence accumulates.

Prognosis of Good syndrome: mortality and morbidity of thymoma associated immunodeficiency in perspective

Good syndrome (GS) or thymoma-associated immunodeficiency, is a rare condition that has only been studied in retrospective case series. General consensus was that GS has a worse prognosis than other humoral immunodeficiencies. In this study, physicians of GS patients completed two questionnaires with a two year interval with data on 47 patients, 499 patient years in total. Results on epidemiology, disease characteristics, and outcome are presented. Mean age at diagnosis was 60years and median follow-up from onset of symptoms was 9years. There was a high frequency of respiratory tract infections due to encapsulated bacteria. Median survival was 14years. Survival was reduced compared to age-matched population controls (5-year survival: 82% versus 95%, p=0.008). In this cohort survival was not associated with gender (HR 0.9, 95% CI 0.3-3.0), autoimmune diseases (HR 2.9, 95% CI 0.8-10.1) or immunosuppressive use (HR 0.3, 95% CI: 0.1-1.2).

Role of Flow Cytometry in the Diagnosis of Chronic Granulomatous Disease: the Egyptian Experience

INTRODUCTION

Chronic granulomatous disease (CGD) is an inherited mutational defect in any of the NADPH oxidase complex, CYBB (gp91-phox), NCF1 (p47-phox), CYBA (p22-phox), NCF2 (p67-phox), or NCF4 (p40-phox) leading to inability of phagocytes to perform effective respiratory burst and thus diminished killing of bacteria and fungi. The identification of defective proteins aids in establishing a diagnosis prior to genetic analysis, which is rather labor-intensive, expensive, and time-consuming.

AIM

The present study aims at assessing the NADPH proteins by performing the intracellular staining with specific monoclonal antibodies and their assessment on flow cytometry. The use of flow cytometry is less laborious and faster to perform than western blot. It also confirms the diagnosis of CGD and detects the affected components allowing proper management of patients.

MATERIALS AND METHODS

Twenty-eight patients from 25 different kindred, clinically suspected as CGD were recruited in Egypt. Dihydrorhodamine test was performed to confirm the diagnosis of the patients. Intracellular staining of NADPH components using specific monoclonal antibodies was performed followed by flow cytometric analysis.

RESULTS

The present study revealed that the most common defective protein in our cohort is p22-phox, found in 13 patients (46.4 % of cases) followed by p47-phox in 8 patients (28.6 %), gp91-phox in 5 patients (17.9 %), and finally p67-phox in 2 patients (7.1 %).

CONCLUSION

In countries with limited resources and yet large number of CGD patients, the analysis of the defective proteins by flow cytometry is an optimum solution for confirming the diagnosis and is a step for targeted sequencing in families seeking prenatal diagnosis.

Hereditary angio-oedema with C1 inhibitor deficiency: Characteristics and diagnostic delay of Czech patients from one centre

BACKGROUND

Hereditary angio-oedema (HAE) is manifested by repeated episodes of localised subcutaneous or sub-mucosal oedema. Symptoms are extremely variable in frequency, localisation, and severity. Atypical or mild clinical symptoms of the disease may lead to erroneous diagnosis, causing diagnostic delay. The goal of this study was to assess how diagnostic delay has changed over 33 years at a single referral centre.

METHODS

We analysed diagnostic delay and first symptoms of HAE in patients who were diagnosed at an immunology department between 1980 and 2013. Patient's records were analysed.

RESULTS

The median diagnostic delay in 77 HAE type 1 and 2 patients was seven (range, 0-42) years. The difference observed in diagnostic delay between probands (18 [0-42] years) and others (1 [0-37] year) was significant (p<0.001). Our data show a significant negative correlation between the length of diagnostic delay and the year of diagnosis in our group of patients (p=0.024). The median age of first symptoms among all HAE patients (N=64) was 17 (1-40) years. The first symptoms of HAE in 64 patients were analysed. Twenty-six patients had abdominal, seventeen peripheral, five facial, two urogenital, and three had laryngeal oedema as the first manifestation of the disease. The last death that was attributed to HAE was in 1977.

CONCLUSIONS

Our observations demonstrate improved awareness of HAE among physicians, as documented by the significant decrease in diagnostic delay. It is believed that earlier treatment will improve patient quality of life and life expectancy.

[Recurrent meningitis and inherited complement deficiency]

Complement deficiency represents 5% of primary immunodeficiencies worldwide. A total of seven patients with deficiencies of the classical complement pathway were reported in the Czech Republic by the end of 2015. Typical manifestations of complement deficiency are recurrent meningitis, other bacterial infections, autoimmunity and kidney disease.Two case reports are presented of patients with molecularly confirmed C7 (compound heterozygote, c.663_644del in exon 6 and c.2350+2T:>C in intron 16) and C8 (homozygous c.1282C>T in exon 9) deficiency. The first patient had four attacks of meningococcal meningitis and an episode of pneumonia of unknown aetiology in childhood. The second had six attacks of meningitis. He also suffered from recurrent infections (otitis media, tonsillitis, chronic mucopurulent rhinitis and subsequent pansinusitis complicated by nasal polyposis) since childhood. No autoimmune disease was documented in either patient. They both received meningococcal and pneumococcal vaccines. Antibiotic prophylaxis was used only in the second patient, leading to a decline in the number of ENT infections.Complement deficiency should be suspected in patients with recurrent meningococcal infections, especially if combined with other infections caused by encapsulated bacteria or autoimmunity diseases. Prophylaxis with conjugate polysaccharide vaccines is recommended and antibiotic prophylaxis should be considered in individual cases.

Detection of impaired IgG antibody formation facilitates the decision on early immunoglobulin replacement in hypogammaglobulinemic patients

Hypogammaglobulinemia (serum IgG lower than 2 SD below the age-matched mean) and clinical symptoms such as increased susceptibility to infection, autoimmune manifestations, granulomatous disease, and unexplained polyclonal lymphoproliferation are considered to be diagnostic hallmarks in patients with common variable immunodeficiency (CVID), the most frequent clinically severe primary immunodeficiency syndrome. In the present study, we investigated patients with hypogammaglobulinemia and no clinical or immunological signs of defective cell-mediated immunity and differentiated two groups on the basis of their IgG antibody formation capacity against a variety of different antigens (bacterial toxins, polysaccharide antigens, viral antigens). Patients with hypogammaglobulinemia and intact antibody production (HIAP) displayed no or only mild susceptibility to infections, while CVID patients showed marked susceptibility to bacterial infections that normalized following initiation of IVIG or subcutaneous immunoglobulin replacement therapy. There was a substantial overlap in IgG serum levels between the asymptomatic HIAP group and the CVID patients examined before immunoglobulin treatment. HIAP patients showed normal levels of switched B-memory cells (CD19(+)CD27(+)IgD(-)), while both decreased and normal levels of switched B-memory cells could be found in CVID patients. IgG antibody response to a primary antigen, tick-borne encephalitis virus (TBEV), was defective in CVID patients, thus confirming their substantial defect in IgG antibody production. Defective IgG antibody production against multiple antigens could also be demonstrated in an adult patient with recurrent infections but normal IgG levels. To facilitate early treatment before recurrent infections may lead to organ damage, the antibody formation capacity should be examined in hypogammaglobulinemic patients and the decision to treat should be based on the finding of impaired IgG antibody production.

Low ficolin-2 levels in common variable immunodeficiency patients with bronchiectasis

Common variable immunodeficiency (CVID) encompasses a heterogeneous group of antibody deficiencies characterized by susceptibility to recurrent infections and sequelae, including bronchiectasis. We investigated the relevance of the lectin complement pathway in CVID patients by analysing ficolin-2 and ficolin-3 serum levels and genotyping single nucleotide polymorphisms (SNPs) in the FCN2 and FCN3 genes. Our results show that ficolin-2 levels in CVID patients are significantly lower (P < 0.0001) than in controls. The lowest ficolin-2 levels are found in CVID patients with bronchiectasis (P = 0.0004) and autoimmunity (P = 0.04). Although serum levels of ficolin-3 were similar in CVID patients and controls, CVID patients with bronchiectasis again showed lower levels when compared to controls (P = 0.0001). Analysis of single nucleotide polymorphisms in the FCN2 gene confirmed known influences on ficolin-2 serum levels, but did not support a genetic basis for the observed ficolin-2 deficiency in CVID. We found that CVID patients with bronchiectasis have very low levels of ficolin-2. The reason for the deficiency of ficolin-2 in CVID and any possible causal relationship is currently unknown. However, as bronchiectasis is a very important factor for morbidity and mortality in CVID, ficolin-2 could also serve as biomarker for monitoring disease complications such as bronchiectasis.

Altered serum cytokine signature in common variable immunodeficiency

PURPOSE

Common variable immunodeficiency (CVID) is the most frequent form of primary symptomatic hypogammaglobulinemia. CVID patients display a number of abnormalities in lymphocyte subpopulations including chronic T-cell activation and decreased numbers of circulating CD4(+) T cells and NK cells. We and others have recently shown that CVID is associated with increased concentration of soluble CD14 (sCD14) and other factors indicating limited microbial translocation.

METHODS

To address the mechanisms of chronic immune activation in CVID, we performed a detailed analysis of cytokine serum levels in 36 patients with CVID, 52 patients with selective IgA deficiency (IgAD), and 56 healthy volunteers.

RESULTS

We show that CVID is associated with elevated serum levels of CXCL-10/IP-10, IL-1R antagonist, TNF-α, IL-10, IL-12 (p40), CCL-2/MCP-1, G-CSF, and CCL-11/eotaxin. The detected cytokine signature is consistent with an ongoing activation of cells of myeloid lineage. In contrast, the levels of cytokines typically produced by CD4(+) T helper cells of Th1 (IFN-γ, IL-2), Th2 (IL-9, IL-13), and Th17 (IL-17) subtypes were suppressed in CVID patients compared to healthy donors.

CONCLUSIONS

Presented data suggest that the altered cytokine profile observed in patients with CVID may be attributed to the activation of monocyte-macrophage and granulocyte lineages, possibly driven by the translocation of bacterial components across the gastrointestinal or respiratory tracts mucosal barrier.

Clinical picture and treatment of 2212 patients with common variable immunodeficiency

BACKGROUND

Common variable immunodeficiency (CVID) is an antibody deficiency with an equal sex distribution and a high variability in clinical presentation. The main features include respiratory tract infections and their associated complications, enteropathy, autoimmunity, and lymphoproliferative disorders.

OBJECTIVE

This study analyzes the clinical presentation, association between clinical features, and differences and effects of immunoglobulin treatment in Europe.

METHODS

Data on 2212 patients with CVID from 28 medical centers contributing to the European Society for Immunodeficiencies Database were analyzed retrospectively.

RESULTS

Early disease onset (<10 years) was very frequent in our cohort (33.7%), especially in male subjects (39.8%). Male subjects with early-onset CVID were more prone to pneumonia and less prone to other complications suggesting a distinct disease entity. The diagnostic delay of CVID ranges between 4 and 5 years in many countries and is particularly high in subjects with early-onset CVID. Enteropathy, autoimmunity, granulomas, and splenomegaly formed a set of interrelated features, whereas bronchiectasis was not associated with any other clinical feature. Patient survival in this cohort was associated with age at onset and age at diagnosis only. There were different treatment strategies in Europe, with considerable differences in immunoglobulin dosing, ranging from 130 up to 750 mg/kg/mo. Patients with very low trough levels of less than 4 g/L had poor clinical outcomes, whereas higher trough levels were associated with a reduced frequency of serious bacterial infections.

CONCLUSION

Patients with CVID are being managed differently throughout Europe, affecting various outcome measures. Clinically, CVID is a truly variable antibody deficiency syndrome.

Cytomegalovirus disease in patients with common variable immunodeficiency: three case reports

Common variable immunodeficiency (CVID) is the most frequent clinically relevant primary immunodeficiency and shows enormous heterogeneity in clinical presentation. Despite clinical immunodeficiency, opportunistic infections are not a typical manifestation of CVID. A retrospective study of 32 patients followed up for 335 patient-years was performed to determine the frequency of cytomegalovirus (CMV) disease. Symptomatic CMV infection was documented in 3 CVID patients. Patients No. 1 and 2 suffered from CMV pneumonia, with complications due to atypical mycobacteriosis in patient No. 1. Patient No. 3 suffered from CMV enteritis. A history of cancer and chronic hepatitis C infection (patient No. 1), immunosuppressive therapy for interstitial lung disease (patient No. 2) and serious enteropathy complicated with malnutrition (patient No. 3) may have contributed to the complications despite only mild abnormalities in T-cell subpopulations. The direct detection of CMV in bronchoalveolar lavage, stool or tissue samples was the most beneficial diagnostic laboratory method, whereas the detection of CMV DNA in blood did not produce positive results. Adequate treatment of CMV disease led to significant clinical improvement in all 3 patients. The frequency of CMV disease appears to be higher than previously described. In our experience, the probability of opportunistic infections in CVID patients increases with secondary comorbidities and their management.

New and recurrent gain-of-function STAT1 mutations in patients with chronic mucocutaneous candidiasis from Eastern and Central Europe

BACKGROUND

Chronic mucocutaneous candidiasis disease (CMCD) may result from various inborn errors of interleukin (IL)-17-mediated immunity. Twelve of the 13 causal mutations described to date affect the coiled-coil domain (CCD) of STAT1. Several mutations, including R274W in particular, are recurrent, but the underlying mechanism is unclear.

OBJECTIVE

To investigate and describe nine patients with CMCD in Eastern and Central Europe, to assess the biochemical impact of STAT1 mutations, to determine cytokines in supernatants of Candida-exposed blood cells, to determine IL-17-producing T cell subsets and to determine STAT1 haplotypes in a family with the c.820C>T (R274W) mutation.

RESULTS

The novel c.537C>A (N179K) STAT1 mutation was gain-of-function (GOF) for γ-activated factor (GAF)-dependent cellular responses. In a Russian patient, the cause of CMCD was the newly identified c.854 A>G (Q285R) STAT1 mutation, which was also GOF for GAF-dependent responses. The c.1154C>T (T385M) mutation affecting the DNA-binding domain (DBD) resulted in a gain of STAT1 phosphorylation in a Ukrainian patient. Impaired Candida-induced IL-17A and IL-22 secretion by leucocytes and lower levels of intracellular IL-17 and IL-22 production by T cells were found in several patients. Haplotype studies indicated that the c.820C>T (R274W) mutation was recurrent due to a hotspot rather than a founder effect. Severe clinical phenotypes, including intracranial aneurysm, are presented.

CONCLUSIONS

The c.537C>A and c.854A>G mutations affecting the CCD and the c.1154C>T mutation affecting the DBD of STAT1 are GOF. The c.820C>T mutation of STAT1 in patients with CMCD is recurrent due to a hotspot. Patients carrying GOF mutations of STAT1 may develop multiple intracranial aneurysms by hitherto unknown mechanisms.

Outcomes of splenectomy in patients with common variable immunodeficiency (CVID): a survey of 45 patients

Splenectomy has been used in patients with common variable immunodeficiency disorders (CVID), mainly in the context of refractory autoimmune cytopenia and suspected lymphoma, but there are understandable concerns about the potential of compounding an existing immunodeficiency. With increasing use of rituximab as an alternative treatment for refractory autoimmune cytopenia, the role of splenectomy in CVID needs to be re-examined. This retrospective study provides the largest cohesive data set to date describing the outcome of splenectomy in 45 CVID patients in the past 40 years. Splenectomy proved to be an effective long-term treatment in 75% of CVID patients with autoimmune cytopenia, even in some cases when rituximab had failed. Splenectomy does not worsen mortality in CVID and adequate immunoglobulin replacement therapy appears to play a protective role in overwhelming post-splenectomy infections. Future trials comparing the effectiveness and safety of rituximab and splenectomy are needed to provide clearer guidance on the second-line management of autoimmune cytopenia in CVID.

Chronic immune activation in common variable immunodeficiency (CVID) is associated with elevated serum levels of soluble CD14 and CD25 but not endotoxaemia

Common variable immunodeficiency (CVID), the most frequent symptomatic immunoglobulin primary immunodeficiency, is associated with chronic T cell activation and reduced frequency of CD4(+) T cells. The underlying cause of immune activation in CVID is unknown. Microbial translocation indicated by elevated serum levels of lipopolysaccharide and soluble CD14 (sCD14) has been linked previously to systemic immune activation in human immunodeficiency virus/acquired immune deficiency syndrome (HIV-1/AIDS), alcoholic cirrhosis and other conditions. To address the mechanisms of chronic immune activation in CVID, we performed a detailed analysis of immune cell populations and serum levels of sCD14, soluble CD25 (sCD25), lipopolysaccharide and markers of liver function in 35 patients with CVID, 53 patients with selective immunoglobulin (Ig)A deficiency (IgAD) and 63 control healthy subjects. In CVID subjects, the concentration of serum sCD14 was increased significantly and correlated with the level of sCD25, C-reactive protein and the extent of T cell activation. Importantly, no increase in serum lipopolysaccharide concentration was observed in patients with CVID or IgAD. Collectively, the data presented suggest that chronic T cell activation in CVID is associated with elevated levels of sCD14 and sCD25, but not with systemic endotoxaemia, and suggest involvement of lipopolysaccharide-independent mechanisms of induction of sCD14 production.

Sequence variants of the TNFRSF13B gene in Czech CVID and IgAD patients in the context of other populations

Mutations in the TNFRSF13B gene, encoding TACI, have been found in common variable immunodeficiency (CVID) and selective IgA deficient (IgAD) patients, but only the association with CVID seems to be significant. In this study, Czech CVID, IgAD and primary hypo/dysgammaglobulinemic (HG/DG) patients were screened for all TNFRSF13B sequence variants. The TNFRSF13B gene was mutated in 4/70 CVID patients (5.7%), 9/161 IgAD patients (5.6%), 1/17 HG/DG patient (5.9%) and none of 195 controls. Eight different mutations were detected, including the most frequent p.C104R and p.A181E mutations as well as 1 novel missense mutation, p.R189K. A significant association of TNFRSF13B gene mutations was observed in both CVID (p=0.01) and IgAD (p=0.002) Czech patients. However, when combined with all published data, only the association with CVID remained significant compared with the controls (9.9% vs. 3.2%, p<10(-6)), while statistical significance disappeared for IgAD (5.7% vs. 3.2%, p=0.145). The silent mutation p.P97P was shown to be associated significantly with CVID compared with the controls in both Czech patients (allele frequency 4.3% vs. 0.2%, p=0.01) and in connection with the published data (5.1% vs. 1.8%, p=0.003). The relevance of some TNFRSF13B gene variants remains unclear and needs to be elucidated in future studies.

Soluble ST2 levels in patients with cardiogenic and septic shock are not predictors of mortality

BACKGROUND

Soluble ST2 (sST2) is an interleukin-33 receptor. sST2 was found to be an independent prognostic factor in patients with myocardial infarction, sepsis and heart failure.

OBJECTIVES

To assess sST2 levels in patients with cardiogenic shock (CS) and septic shock (SS), and to evaluate the prognostic value of sST2 for short-term mortality.

METHODS

The present prospective observational study evaluated 32 patients with CS, 17 patients with SS and 61 patients with ST segment elevation myocardial infarction (STEMI )(control group). Samples of serum were collected eight times and the follow-up time was three months.

RESULTS

sST2 levels were elevated from admission in SS patients relative to patients with CS and STEMI, who exhibited peak sST2 levels 24 h after admission. On admission, CS patients had a median (5th percentile; 95th percentile) sST2 level of 62.5 pg/mL (8.3 pg/mL; 315.8 pg/mL) and SS patients had a median sST2 level of 216.4 pg/mL (46.8 pg/mL; 364.4 pg/mL). ROC analysis found sST2 to be a biomarker that could distinguish between CS and SS at admission (area under the curve [AUC] 0.813; P<0.01) with a cut-off value of 210.4 pg/mL. Patients with STEMI had significantly lower sST2 levels at admission (20.3 pg/mL (4.2 pg/mL; 339.8 pg/mL) compared with CS patients. The AUC of the ROC analysis was 0.671 (P=0.007) for the detection of CS in patients with STEMI. Only a weak correlation was observed between sST2 and B-type natriuretic peptide (r=0.376, P=0.05) and sST2 and N-terminal pro-B-type natriuretic peptide (r=0.496, P=0.019). No statistically significant differences were observed in sST2 levels in patients with CS and SS relative to three-month mortality.

CONCLUSION

Levels of sST2 at admission are significantly higher in patients with SS compared with CS. sST2 could be a diagnostic marker to distinguish SS and CS as well as CS and STEMI at the time of admission. Levels of sST2 are related to levels of natriuretic peptides in CS but not in SS. sST2 levels are not a suitable prognostic marker for patients with CS and SS.

Soluble BAFF levels inversely correlate with peripheral B cell numbers and the expression of BAFF receptors

The TNF family member protein BAFF/BLyS is essential for B cell survival and plays an important role in regulating class switch recombination as well as in the selection of autoreactive B cells. In humans, increased concentrations of soluble BAFF are found in different pathological conditions, which may be as diverse as autoimmune diseases, B cell malignancies, and primary Ab deficiencies (PAD). Because the mechanisms that regulate BAFF levels are not well understood, we newly developed a set of mAbs against human BAFF to study the parameters that determine the concentrations of soluble BAFF in circulation. Patients with PAD, including severe functional B cell defects such as BTK, BAFF-R, or TACI deficiency, were found to have higher BAFF levels than asplenic individuals, patients after anti-CD20 B cell depletion, chronic lymphocytic leukemia patients, or healthy donors. In a comparable manner, mice constitutively expressing human BAFF were found to have higher concentrations of BAFF in the absence than in the presence of B cells. Therefore, our data strongly suggest that BAFF steady-state concentrations mainly depend on the number of B cells as well as on the expression of BAFF-binding receptors. Because most patients with PAD have high levels of circulating BAFF, the increase in BAFF concentrations cannot compensate defects in B cell development and function.

Recurrent laryngeal papillomatosis: successful treatment with human papillomavirus vaccination

The authors describe the case of a 5-year-old girl with recurrent laryngeal papillomatosis (RLP) due to human papillomavirus (HPV) type 11, who required frequent surgical treatment. Complete recovery occurred after HPV vaccination (Gardasil). Confirmed remission of RLP has continued during the 17 months of follow-up since vaccination. The authors conclude that HPV vaccination may represent a new therapeutic option in this situation.

NOD2 polymorphisms in clinical phenotypes of common variable immunodeficiency disorders

Common variable immunodeficiency disorders (CVIDs) are a heterogeneous group of diseases characterized by hypogammaglobulinaemia and consequent susceptibility to infection. CVID patients commonly develop a variety of additional manifestations for which the causative factors are not fully understood. Two such manifestations are granulomatous disease and enteropathy. Because the ability to predict complications would aid clinical management, we continue to search for possible disease modifier genes. NOD2 acts a microbial sensor and is involved in proinflammatory signalling. Particular mutations of the NOD2 gene are associated with Crohn's disease including gly908arg, leu1007finsc and arg702trp polymorphisms. We hypothesized that NOD2 polymorphisms may be a disease modifier gene towards an enteropathic or granulomatous phenotype within CVIDs. Sequence-specific primers returned genotypes for 285 CVID patients from centres across the United Kingdom and Europe. We present the frequencies of the different phenotypes of patients within our international cohort. Arg702trp polymorphisms were significantly less frequent than wild-type (WT) (P = 0·038) among international CVID patients with splenomegaly. Gly908arg polymorphisms were more prevalent than WT in UK patients with autoimmune disorders (P = 0·049) or enteropathy (P = 0·049). NOD2 polymorphisms were not more prevalent than WT in CVID patients with clinical phenotypes of granulomata. UK allele frequencies of 0·014, 0·056 and 0·026 were found for gly908arg, arg702trp and leu1007finsc NOD2 polymorphisms, respectively. These do not differ significantly from UK immunocompetent controls confirming, as expected, that in addition these NOD2 polymorphisms do not confer susceptibility to CVIDs per se.

[A simple method for the detection of CD154 (CD40L) on peripheral blood lymphocytes]

OBJECTIVE

CD154 (also called CD40L) is a transmembrane glycoprotein predominantly expressed on the surface membrane of activated CD4+ T cells. Its receptor CD40 is present on all B cells, but also on other cells. The interaction CD154-CD40 is necessary for the optimal development of the adaptive immune response and also has consequences for the modulation of the inflammatory response. A defect in the expression of CD154 is pathognomonic of congenital immunodeficiency called X-linked Hyper-IgM syndrome (XHIGM). To detect the abnormality of CD154 is essential for making the diagnosis of XHIGM.

MATERIAL AND METHODS

We worked out a microtest for the detection of CD154 expression on in vitro activated CD4+ T cells in whole blood and compared it with that on isolated cells from peripheral blood. Heparinized peripheral blood was activated with phorbol 12-myristate 13-acetate and ionomycin for 4 hours, labeled with monoclonal antibodies and analyzed by flow cytometry. Considering that the CD4 marker on the plasma membrane surface decreases during the activation, CD4+ T cells are mostly recognized as CD5+/CD8- cells. Their activation is monitored based on the expression of CD69. Three-colour immunofluorescence staining was used for simultaneous detection of CD154.

RESULTS

Ten blood donors were tested. As little as 0.5 ml of heparinized whole blood is needed to complete the test. Optimal time for activation and detection of CD154 on T lymphocytes is 4 hours. We found that the number of CD4 molecules on the surface of T cells decreases during the activation. The expression of CD154 in our whole blood microtest is fully comparable with that in the test on isolated leukocytes.

CONCLUSION

The presented microtest for the detection of CD154 on activated lymphocytes in whole blood is fast and blood saving, since as little as 0.5 ml of blood is needed to complete it. It can be recommended as the initial test for suspected hyper-IgM syndrome in children. We demonstrate that this screening method can help to detect also carriers of XHIGM.

No association of FCRN promoter VNTR polymorphism with the rate of maternal-fetal IgG transfer

The neonatal Fc receptor (FcRn) plays a critical role in maternal-fetal IgG transfer. Recently, a functionally active promoter polymorphism in the FCRN gene, represented by variable number of tandem repeats (VNTR), has been described. We analysed 103 single fetal samples and 103 paired maternal and fetal samples collected from umbilical cord blood of full-term neonates born from the 38th to the 41st week of pregnancy and detected no significant influence of maternal FCRN VNTR genotype on maternal IgG levels or of fetal FCRN VNTR genotype on fetal IgG levels or the fetal/maternal IgG ratio.

Mutations in STAT3 and diagnostic guidelines for hyper-IgE syndrome

BACKGROUND

The hyper-IgE syndrome (HIES) is a primary immunodeficiency characterized by infections of the lung and skin, elevated serum IgE, and involvement of the soft and bony tissues. Recently, HIES has been associated with heterozygous dominant-negative mutations in the signal transducer and activator of transcription 3 (STAT3) and severe reductions of T(H)17 cells.

OBJECTIVE

To determine whether there is a correlation between the genotype and the phenotype of patients with HIES and to establish diagnostic criteria to distinguish between STAT3 mutated and STAT3 wild-type patients.

METHODS

We collected clinical data, determined T(H)17 cell numbers, and sequenced STAT3 in 100 patients with a strong clinical suspicion of HIES and serum IgE >1000 IU/mL. We explored diagnostic criteria by using a machine-learning approach to identify which features best predict a STAT3 mutation.

RESULTS

In 64 patients, we identified 31 different STAT3 mutations, 18 of which were novel. These included mutations at splice sites and outside the previously implicated DNA-binding and Src homology 2 domains. A combination of 5 clinical features predicted STAT3 mutations with 85% accuracy. T(H)17 cells were profoundly reduced in patients harboring STAT3 mutations, whereas 10 of 13 patients without mutations had low (<1%) T(H)17 cells but were distinct by markedly reduced IFN-gamma-producing CD4(+)T cells.

CONCLUSION

We propose the following diagnostic guidelines for STAT3-deficient HIES. Possible: IgE >1000IU/mL plus a weighted score of clinical features >30 based on recurrent pneumonia, newborn rash, pathologic bone fractures, characteristic face, and high palate. Probable: These characteristics plus lack of T(H)17 cells or a family history for definitive HIES. Definitive: These characteristics plus a dominant-negative heterozygous mutation in STAT3.