Clinical and experimental treatment of primary humoral immunodeficiencies.

Selective IgA deficiency (sIgAD), common variable immunodeficiency (CVID), and transient hypogammaglobulinemia of infancy (THI) are the most frequent forms of primary antibody deficiencies. Difficulties in initial diagnosis, especially in the early childhood, the familiar occurrence of these diseases, as well as the possibility of progression to each other suggest common cellular and molecular patomechanism and a similar genetic background. In this review, we discuss both similarities and differences of these three humoral immunodeficiencies, focusing on current and novel therapeutic approaches. We summarize immunoglobulin substitution, antibiotic prophylaxis, treatment of autoimmune diseases, and other common complications, i.e. cytopenias, gastrointestinal complications, and granulomatous disease. We discuss novel therapeutic approaches such as allogenic stem cell transplantation and therapies targeting-specific proteins, dependent on the patient's genetic defect. The diversity of possible therapeutics models results from a great heterogeneity of the disease variants, implying the need of personalized medicine approach as a future of primary humoral immunodeficiencies treatment.

Transcriptome profiling of regulatory T cells from children with transient hypogammaglobulinemia of infancy.

Transient hypogammaglobulinemia of infancy (THI) is one of the most common forms of hypogammaglobulinemia in the early childhood. THI is usually associated with chronic, recurrent bacterial and viral infections, life-threatening in some cases, yet its pathogenesis is still largely unknown. As our previous findings indicated the possible role of Treg cells in the pathomechanism of THI, the aim of the current study was to investigate gene expression profile of Treg cells isolated from THI patients. The transcriptome-wide gene profiling was performed using microarray technology on THI patients in two time-points: during (THI-1), and in resolution phase (THI-2) of hypogammaglobulinemia. As a result, a total of 1086 genes were differentially expressed in THI-1 patients, when compared to THI-2 as well as control group. Among them, 931 were up- and 155 downregulated, and part of them encodes genes important for Treg lymphocyte biology and function, i.e. transcription factors/cofactors that regulate FOXP3 expression. Thus, we postulate that Treg cells isolated from THI patients during hypogammaglobulinemia display enhanced suppressor transcriptome signature. Treg expression profile of THI children after normalization of Ig levels largely resembles the results obtained in healthy control group, suggesting THI Treg transcriptome seems to return to that observed in healthy children. Taken together, we suggest that THI pathomechanism is associated not only with transiently elevated Treg cell numbers, but also with their enhanced regulatory/inhibitory functions. These findings expand our knowledge of human Treg cells and may be useful for the future diagnosis or management of THI.

The level of myeloid-derived suppressor cells positively correlates with regulatory T cells in the blood of children with transient hypogammaglobulinaemia of infancy.

INTRODUCTION: Transient hypogammaglobulinaemia of infancy (THI) is a primary immunodeficiency characterised by low levels of immunoglobulin G (often with concomitant decrease of IgA and sometimes also of IgM) with still unknown exact reason. A delayed normalisation of the immunoglobulin level in THI may be associated with a transiently elevated number of regulatory T cells (Treg). Although in cancer and chronic inflammation it was shown that the level of Treg cells can be increased by myeloid-derived suppressor cells (MDSCs), until now no studies have been performed in the context of the role of MDSCs in THI and their correlation with Treg cells. Consequently, we aimed to determine the occurrence of MDSCs in the peripheral blood of children with THI and correlate their level with the level of Treg cells. MATERIAL AND METHODS: Flow cytometry analyses of Mo-MDSCs and Gr-MDSCs, characterised as HLA-DR-CD11b+CD15-CD14+ and HLA-DR-CD11b+CD15+CD14-, respectively, and Treg (CD4+CD25+Foxp3+) cells were performed. RESULTS: The proportion of Mo-MDSCs and Gr-MDSCs was significantly higher in the group of THI patients with elevated level of Treg cells (from the 95% confidence interval level of healthy controls). The cells with Mo-MDSC and Gr-MDSC characteristics positively correlated with the level of Treg cells. Moreover, children with a higher proportion of circulating Treg cells, and thereby higher level of MDSCs, showed delayed normalisation of IgG level and recovery. CONCLUSIONS: These findings show for the first time that MDSCs may be involved in the pathomechanism of THI, probably acting through the induction of Treg cells.

Neurodegenerative changes detected by neuroimaging in a patient with contiguous X-chromosome deletion syndrome encompassing BTK and TIMM8A genes.

INTRODUCTION: In this study we describe a patient with gross deletion containing the BTK and TIMM8A genes. Mutations in these genes are responsible for X-linked agammaglobulinemia and Mohr-Tranebjaerg syndrome, respectively. X linked agammaglobulinemia is a rare primary immunodeficiency characterized by low levels of B lymphocytes and recurrent microbial infections, whereas, Mohr-Tranebjaerg syndrome is a progressive neurodegenerative disorder with early onset of sensorineural deafness. MATERIAL AND METHODS: For neuroimaging, the magnetic resonance imaging and magnetic resonance spectroscopy of the brain were performed. Microarray analysis was performed to establish the extent of deletion. RESULTS: The first clinical symptoms observed in our patient at the age of 6 months were connected with primary humoral immunodeficiency, whereas clinical signs of MTS emerged in the third year of live. Interestingly, the loss of speech ability was not accompanied by hearing failure. Neuroimaging of the brain suggested leukodystrophy. Molecular tests revealed contiguous X-chromosome deletion syndrome encompassing BTK (from exons 6 through 19) and TIMM8A genes. The loss of the patient's DNA fragment was accurately localized from 100 601 727 to 100 617 576 bp on chromosome's loci Xq22.1. CONCLUSIONS: We diagnosed XLA-MTS in the first Polish patient on the basis of particular molecular methods. We detected neurodegenerative changes in MRI and MR spectroscopy in this patient. Our results provide further insight into this rare syndrome.

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).

[Granulomatous lymphocytic interstitial lung disease (GLILD) as a manifestation of pulmonary changes in common variable immunodeficiency (CVID) ­ case report].

Common variable immunodeficiency (CVID) comprise different kinds of primary hypogammaglobulinemias of mostly unknown etiology. The onset of the disease and its clinical symptoms may appear as well in children as in adults. Apart from susceptibility to bacterial, viral and fungal infections, other clinical signs (autoimmunization, non-infectious lung and gastrointestinal diseases, neoplasm) are frequently observed. About 58% of patients with CVID develops granulomatous and lymphocytic interstitial lung disease (GLILD) associated with early mortality.

Haploinsufficiency at the human IFNGR2 locus contributes to mycobacterial disease.

Mendelian susceptibility to mycobacterial diseases (MSMD) is a rare syndrome, the known genetic etiologies of which impair the production of, or the response to interferon-gamma (IFN-γ). We report here a patient (P1) with MSMD whose cells display mildly impaired responses to IFN-γ, at levels, however, similar to those from MSMD patients with autosomal recessive (AR) partial IFN-γR2 or STAT1 deficiency. Whole-exome sequencing (WES) and Sanger sequencing revealed only one candidate variation for both MSMD-causing and IFN-γ-related genes. P1 carried a heterozygous frame-shift IFNGR2 mutation inherited from her father. We show that the mutant allele is intrinsically loss-of-function and not dominant-negative, suggesting haploinsufficiency at the IFNGR2 locus. We also show that Epstein-Barr virus transformed B lymphocyte cells from 10 heterozygous relatives of patients with AR complete IFN-γR2 deficiency respond poorly to IFN-γ, in some cases as poorly as the cells of P1. Naive CD4(+) T cells and memory IL-4-producing T cells from these individuals also responded poorly to IFN-γ, whereas monocytes and monocyte-derived macrophages (MDMs) did not. This is consistent with the lower levels of expression of IFN-γR2 in lymphoid than in myeloid cells. Overall, MSMD in this patient is probably due to autosomal dominant (AD) IFN-γR2 deficiency, resulting from haploinsufficiency, at least in lymphoid cells. The clinical penetrance of AD IFN-γR2 deficiency is incomplete, possibly due, at least partly, to the variability of cellular responses to IFN-γ in these individuals.

High-content cytometry and transcriptomic biomarker profiling of human B-cell activation.

BACKGROUND: Primary antibody deficiencies represent the most prevalent, although very heterogeneous, group of inborn immunodeficiencies, with a puzzling complexity of cellular and molecular processes involved in disease pathogenesis. OBJECTIVE: We aimed to study in detail the kinetics of CD40 ligand/IL-21-induced B-cell differentiation to define new biomarker sets for further research into primary antibody deficiencies. METHODS: We applied high-content screening methods to monitor B-cell activation on the cellular (chip cytometry) and transcriptomic (RNA microarray) levels. RESULTS: The complete activation process, including stepwise changes in protein and RNA expression patterns, entry into the cell cycle, proliferation and expression of activation-induced cytidine deaminase (AID), DNA repair enzymes, and post-class-switch expression of IgA and IgG, was successfully monitored during in vitro differentiation. We identified a number of unknown pathways engaged during B-cell activation, such as CXCL9/CXCL10 secretion by B cells. Finally, we evaluated a deduced set of biomarkers on a group of 18 patients with putative or proved intrinsic B-cell defects recruited from the European Society for Immunodeficiencies database and successfully predicted 2 AID defects and 1 DNA repair defect. Complete absence of class-switched B cells was a sensitive predictor of AID deficiency and should be further evaluated as a diagnostic biomarker. CONCLUSION: The biomarkers found in this study could be used to further study the complex process of B-cell activation and to understand conditions that lead to the development of primary antibody deficiencies.

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.

BCG vaccination in patients with severe combined immunodeficiency: complications, risks, and vaccination policies.

BACKGROUND: Severe combined immunodeficiency (SCID) is a syndrome characterized by profound T-cell deficiency. BCG vaccine is contraindicated in patients with SCID. Because most countries encourage BCG vaccination at birth, a high percentage of patients with SCID are vaccinated before their immune defect is detected. OBJECTIVES: We sought to describe the complications and risks associated with BCG vaccination in patients with SCID. METHODS: An extensive standardized questionnaire evaluating complications, therapeutics, and outcomes regarding BCG vaccination in patients given a diagnosis of SCID was widely distributed. Summary statistics and association analysis was performed. RESULTS: Data on 349 BCG-vaccinated patients with SCID from 28 centers in 17 countries were analyzed. Fifty-one percent of the patients had BCG-associated complications, 34% disseminated and 17% localized (a 33,000- and 400-fold increase, respectively, over the general population). Patients receiving early vaccination (≤1 month) showed an increased prevalence of complications (P = .006) and death caused by BCG-associated complications (P < .0001). The odds of experiencing complications among patients with T-cell numbers of 250/µL or less at diagnosis was 2.1 times higher (95% CI, 1.4-3.4 times higher; P = .001) than among those with T-cell numbers of greater than 250/µL. BCG-associated complications were reported in 2 of 78 patients who received antimycobacterial therapy while asymptomatic, and no deaths caused by BCG-associated complications occurred in this group. In contrast, 46 BCG-associated deaths were reported among 160 patients treated with antimycobacterial therapy for a symptomatic BCG infection (P < .0001). CONCLUSIONS: BCG vaccine has a very high rate of complications in patients with SCID, which increase morbidity and mortality rates. Until safer and more efficient antituberculosis vaccines become available, delay in BCG vaccination should be considered to protect highly vulnerable populations from preventable complications.

[Immune tolerance mechanisms--brief review]. / Krótka charakterystyka mechanizmów tolerancji immunologicznej.

The purpose of the immune system is not only to fight off pathogens but also to keep a tolerance to self-antigens. In central tolerance, major mechanisms include apoptosis (for T cells) and receptor editing (for B cells). Regulatory T cells appear to be the most important in peripheral tolerance. Innate immune cells also influence the maintenance of immune tolerance. We have provided an overall review of all these mechanisms. Successful restoration of the immune tolerance is the target of new strategies in autoimmune diseases therapy.

[STAT3 mutation in a child with hyper-IgE syndrome and incomplete clinical features]. / Mutacja genu STAT3 u dziecka z zespolem hiperimmunoglobulinemii E o niepelnej manifestacji klinicznej.

We described mutation of STAT3 gene, typical for autosomal dominant hiperimmunoglobulin E syndrome (HIES), in a child with recurrent skin abscesses and respiratory tract infections without skeletal and connective tissue anomalies.

Thrombocytopenia in common variable immunodeficiency patients - clinical course, management, and effect of immunoglobulins.

Common variable immunodeficiency (CVID) is a primary immunodeficiency of humoral immunity with heterogeneous clinical features. Diagnosis of CVID is based on hypogammaglobulinaemia, low production of specific antibodies, and disorders of cellular immunity. The standard therapy includes replacement of specific antibodies with human immunoglobulin, prophylaxis, and symptomatic therapy of infections. High prevalence of autoimmunity is characteristic for CVID, most commonly: thrombocytopaenia and neutropaenia, celiac disease, and systemic autoimmune diseases. The study included seven children diagnosed with CVID and treated with immunoglobulin substitution from 2 to 12 years. Thrombocytopenia was diagnosed prior to CVID in four children, developed during immunoglobulin substitution in three children. In one boy with CVID and thrombocytopaenia, haemolytic anaemia occurred, so a diagnosis of Evans syndrome was established. Therapy of thrombocytopaenia previous to CVID included steroids and/or immunoglobulins in high dose, and azathioprine. In children with CVID on regular immunoglobulin substitution, episodes of acute thrombocytopaenia were associated with infections and were treated with high doses of immunoglobulins and steroids. In two patients only chronic thrombocytopaenia was noted. Splenectomy was necessary in one patient because of severe course of thrombocytopaenia. The results of the study indicated a supportive role of regular immunoglobulin substitution in patients with CVID and chronic thrombocytopaenia. However, regular substitution of immunoglobulins in CVID patients did not prevent the occurrence of autoimmune thrombocytopaenia episodes or exacerbations of chronic form. In episodes of acute thrombocytopaenia or exacerbations of chronic thrombocytopaenia, infusions of immunoglobulins in high dose are effective, despite previous regular substitution in the replacing dose.

Gene Signature of Regulatory T Cells Isolated from Children with Selective IgA Deficiency and Common Variable Immunodeficiency.

Selective IgA deficiency (SIgAD) is the most common form and common variable immunodeficiency (CVID) is the most symptomatic form of predominant antibody deficiency. Despite differences in the clinical picture, a similar genetic background is suggested. A common feature of both disorders is the occurrence of autoimmune conditions. Regulatory T cells (Tregs) are the major immune cell type that maintains autoimmune tolerance. As the different types of abnormalities of Treg cells have been associated with autoimmune disorders in primary immunodeficiency (PID) patients, in our study we aimed to analyze the gene expression profiles of Treg cells in CVID and SIgAD patients compared to age-matched healthy controls. The transcriptome-wide gene profiling was performed by microarray technology. As a result, we analyzed and visualized gene expression patterns of isolated population of Treg cells. We showed the differences at the gene level between patients with and without autoimmunizations. Our findings suggest that the gene signatures of Treg cells isolated from SIgAD and CVID patients differ from age-matched healthy controls and from each other, presenting transcriptional profiles enriched in innate immune or Th response, respectively. The occurrence of autoimmunity in both types of PID is associated with down-regulation of class I IFNs signaling pathways. In summary, our findings improve our understanding of Treg dysfunctions in patients with common PIDs and associated autoimmunity.

[Primary selective IgM deficiency--forgotten primary immunodeficiency?]. / Izolowany niedobór IgM--ignorowany pierwotny niedobór odpornosci?

Immunoglobulin M is a pentamer found in the intravascular compartment and on the surface of B lymphocytes. It is the antibody isotype produced initially in the immune response, and the first immunoglobulin class to be synthesized by a fetus or newborn. IgM antibodies do not cross the placenta. Decreased levels of IgM have been associated with autoimmune disease, several primary immunodeficiency but exist also as selected primary immunodeficiency.

T lymphocytes and NK cells in X-linked agammaglobulinemia.

Seven boys with diagnosis of X-linked agammaglobulinemia on regular substitution of immunoglobulins were included into study. The patients showed episodes of infections but the clinical course was mild with good response to antibiotics. All patients developed, with time, the chronic sinusitis with proliferation of mucous membrane, two patients showed bronchiectases. The number of T lymphocytes, ratio of CD4:CD8 subpopulations, response to stimulation and NK number were assayed with flow cytometry and cell culture. Results showed CD4:CD8 ratio within normal value in majority of patients, reverse ratio in 2 boys, increased number of activated T cells (CD3/HLA-DR) in one of them. The number of NK cells was different from lack of these cells to high number. Response of T cells to stimulation (mitogens and CD3) were normal in majority of assays. There were no associations between clinical course and observed changes in T or NK cell populations. Further studies on number and function of NK cells are needed.

Novel IL2RG Gene Mutation in One of Dizygotic Twins Causing Profound Changes of Receptor Structure.

In this study, we report a 4-month-old boy with T-B+NK- severe combined immunodeficiency (SCID) due to a novel mutation in exon 2 of IL2RG, the gene encoding the interleukin (IL) common gamma chain (γc) of the cytokine receptors for IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21. The patient was born from a twin pregnancy. He manifested recurrent infections of the gastrointestinal tract, whereas his twin brother was asymptomatic with no immune defects. In order to evaluate the effect of this unreported variant on the protein structure, a structural modeling process was performed showing prominent biochemical alterations of the protein features, including molecular weight, isoelectric charge, and possible changes to its secondary and tertiary structure.

Preparations of intravenous immunoglobulins diminish the number and proinflammatory response of CD14+CD16++ monocytes in common variable immunodeficiency (CVID) patients.

We have studied the effect of intravenous immunoglobulins (IVIG) on monocyte subpopulations and cytokine production in patients with CVID. The absolute number of CD14(+)CD16(++) monocytes decreased on average 2.5-fold 4h after IVIG and after 20h returned to the baseline. The cytokine level in the supernatants of peripheral blood mononuclear cells (PBMC) after ex vivo LPS stimulation demonstrated the >2-fold decrease in TNF production 4h after IVIG. The TNF expression, which is higher in the CD14(+)CD16(++) monocytes, was decreased in these cells by IVIG in 4/7 CVID cases. In vitro exposure of the healthy individuals' monocytes to the IVIG preparation resulted in reduced TNF production, which was overcome by blockade of the FcγRIIB in the CD14(+)CD16(++) CD32B(high) monocytes. Our data suggest that reduction in the number of CD14(+)CD16(++) monocytes and the blockade of their cytokine production via triggering CD32B can contribute to the anti-inflammatory action of IVIG.

[Educational program for doctors and nurses taking care for primary immunodeficiency patients treated with subcutaneous immunoglobulins]. / Propozycja programu edukacyjnego dla lekarzy i pielegniarek zajmujacych sie terapia substytucyjna podskórnymi preparatami immunoglobulin u pacjentów z pierwotnymi niedoborami odpornosci.

Primary immunodeficiency diseases (PIDs) are presenting the most common in childhood. PID are genetically determined disorders of the immune system resulting in greatly enhanced susceptibility to infectious disease. Therapy in these group of patients preventing infectious diseases is immunoglobulin (Ig) replacement therapy. Nowadays the quality of life is very important issue which doctors should consider treating their patients. The subcutaneous immunoglobulins appears to be the best solution for them. Treating patients with subcutaneous Ig require good educational programme not only for patients but also for doctors and nurses. We would like to provide practical guidelines for identifying patients who should be referred for assessment of possible immunodeficiency and give some practical instructions how to start and follow-up subcutaneous therapy in all centers of immunology in Poland who are engaged in this kind of treatment.

Selective downregulation of natural killer activating receptors on NK cells and upregulation of PD-1 expression on T cells in children with severe and/or recurrent Herpes simplex virus infections.

Severe, recurrent or atypical Herpes simplex virus (HSV) infections are still posing clinical and diagnostic problem in clinical immunology facilities. However, the molecular background of this disorder is still unclear. The aim of this study was to investigate the expression of activating receptors on NK cells (CD16, NKp46, NKG2D, NKp80, 2B4, CD48 and NTB-A) and checkpoint molecule PD-1 on T lymphocytes and NK cells, in patients with severe and/or recurrent infections with HSV and age-matched healthy control subjects. As a result, we noticed that patients with severe and/or recurrent infection with HSV had significantly lower percentage of CD16brightCD56dim and higher percentage of CD16dimCD56bright NK cell subsets, when compared to control subjects, which may be associated with abnormal NK cell maturation during chronic HSV infection. Patients had also significantly downregulated expression of CD16 receptor on CD16bright NK cells. The expression of activating receptors was significantly reduced on patients' NK cells - either both the percentage of NK cells expressing the receptor and MFI of its expression (NKp46, NKp80 and 2B4 on CD16brightCD56dim cells and NKp46 on CD16dimCD56bright cells) or only MFI (NKG2D on both NK cell subsets). It should be noted that the reduction of receptor expression was limited to NK cells, since there was no differences in the percentage of receptor-positive cells or MFI on T cells. However, NTB-A receptor was the only one which expression was not only simultaneously changed in patients' NK and T cells, but also significantly upregulated on CD16dimCD56bright NK cell and CD8+ cell subsets. Patients had also upregulated proportion of CD4+ T cells expressing PD-1. Thus, we suggest that an increased percentage of PD-1+ cells may represent an independent indirect mechanism of downregulation of antiviral response, separate from the reduction of NK cell activating receptors expression. Altogether, our studies indicate two possible mechanisms which may promote perpetuation of HSV infection: 1) selective inhibition of activating receptors on NK cells, but not on T cells, and 2) upregulation of checkpoint molecule PD-1 on CD4+ T cells.