Clinical heterogeneity in families with multiple cases of inborn errors of immunity.

BACKGROUND: Inborn errors of immunity (IEI) are a diverse range of genetic immune system illnesses affecting the innate and/or adaptive immune systems. Variable expressivity and incomplete penetrance have been reported in IEI patients with similar clinical diagnoses or even the same genetic mutation. METHODS: Among all recorded patients in the national IEI registry, 193 families with multiple cases have been recognized. Clinical, laboratory and genetic variability were compared between 451 patients with different IEI entities. RESULTS: The diagnosis of the first children led to the earlier diagnosis, lower diagnostic delay, timely treatment and improved survival in the second children in the majority of IEI. The highest discordance in familial lymphoproliferation, autoimmunity and malignancy were respectively observed in STK4 deficiency, DNMT3B deficiency and ATM deficiency. Regarding immunological heterogeneity within a unique family with multiple cases of IEI, the highest discordance in CD3+, CD4+, CD19+, IgM and IgA levels was observed in syndromic combined immunodeficiencies (CID), while non-syndromic CID particularly severe combined immunodeficiency (SCID) manifested the highest discordance in IgG levels. Identification of the first ATM-deficient patient can lead to improved care and better survival in the next IEI children from the same family. CONCLUSION: Intrafamilial heterogeneity in immunological and/or clinical features could be observed in families with multiple cases of IEI indicating the indisputable role of appropriate treatment and preventive environmental factors besides specific gene mutations in the variable observed penetrance or expressivity of the disease. This also emphasizes the importance of implementing genetic evaluation in all members of a family with a history of IEI even if there is no suspicion of an underlying IEI as other factors besides the underlying genetic defects might cause a milder phenotype or delay in presentation of clinical features. Thus, affected patients could be timely diagnosed and treated, and their quality of life and survival would improve.

The Evaluation of Hematological Parameters and Their Correlation with Disease Prognosis in COVID-19 Disease in Iran.

Background: Since 2019, Coronavirus has been a highly contagious disease. The COVID-19 outbreak was declared a pandemic by the World Health Organization in March 2020. Variable laboratory findings are reported in COVID-19 patients, among which elevated levels of D-dimer, lactate dehydrogenase, as well as lymphopenia, have been reported to be associated with increased severity of disease symptoms requiring ventilator support, intensive care unit admission, and mortality. Materials and Methods: In the current study, inclusion criteria were: patient age above 18 years and hospitalization in the Imam Khomeini hospital with COVID-19 disease confirmed with nasopharyngeal swab polymerase chain reaction tests. Levels of white blood cells, neutrophils, lymphocytes, hemoglobin, platelets, D-dimer, C-reactive protein, LDH, and ferritin were measured and their correlation with the final patients' outcome was evaluated. Results: A total of 208 patients were included in the present study. Higher neutrophil to lymphocyte ratio, (WBC count excluding lymphocyte)/lymphocyte, LDH, platelet to lymphocyte ratio, ferritin, and D-dimer were significantly related to O2 dependency. Neutrophil to lymphocyte ratio, (WBC count excluding lymphocyte)/lymphocyte and LDH were significantly related to higher rates of mortality. Higher Hb and lymphocyte count were significantly related to higher rates of survival. Conclusion: Hematological parameters including neutrophil to lymphocyte ratio, (WBC count excluding lymphocyte)/lymphocyte, LDH, platelet to lymphocyte ratio, ferritin, D-dimer, Hb, and lymphocyte count were significantly related to the prognosis of patients with COVID-19 disease. This could help decide which COVID-19 patients have priority for hospitalization and intensive medical care, particularly when the pandemic disease causes limitations in healthcare service.

Neuronal nitric oxide synthase inhibition accelerated the removal of fluoxetine's anxiogenic activity in an animal model of PTSD.

While SSRIs are the current first-line pharmacotherapies against post-traumatic stress disorder (PTSD), they suffer from delayed onset of efficacy and low remission rates. One solution is to combine SSRIs with other treatments. Neuronal nitric oxide synthase (nNOS) has been shown to play a role in serotonergic signaling, and there is evidence of synergism between nNOS modulation and SSRIs in models of other psychiatric conditions. Therefore, in this study, we combined subchronic fluoxetine (Flx) with 7-nitroindazole (NI), a selective nNOS inhibitor, and evaluated their efficacy against anxiety-related behavior in an animal model of PTSD. We used the underwater trauma model to induce PTSD in rats. Animals underwent the open field (OFT) and elevated plus maze tests on days 14 (baseline) and 21 (post-treatment) after PTSD induction to assess anxiety-related behaviors. Between the two tests, the rats received daily intraperitoneal injections of 10 mg/kg Flx or saline, and were injected intraperitoneally before the second test with either 15 mg/kg NI or saline. The change in behaviors between the two tests was compared between treatment groups. Individual treatment with both Flx and NI had anxiogenic effects in the OFT. These effects were associated with modest increases in cFOS expression in the hippocampus. Combination therapy with Flx + NI did not show any anxiogenic effects, while causing even higher expression levels of cFOS. In conclusion, addition of NI treatment to subchronic Flx therapy accelerated the abrogation of Flx's anxiogenic properties. Furthermore, hippocampal activity, as evidenced by cFOS expression, was biphasically related to anxiety-related behavior.

B- and T-Cell Subset Abnormalities in Monogenic Common Variable Immunodeficiency.

Common variable immunodeficiency (CVID) is a heterogeneous group of inborn errors of immunity characterized by reduced serum concentrations of different immunoglobulin isotypes. CVID is the most prevalent symptomatic antibody deficiency with a broad range of infectious and non-infectious clinical manifestations. Various genetic and immunological defects are known to be involved in the pathogenesis of CVID. Monogenic defects account for the pathogenesis of about 20-50% of CVID patients, while a variety of cases do not have a defined genetic background. Deficiencies in molecules of B cell receptor signaling or other pathways involving B-cell development, activation, and proliferation could be associated with monogenetic defects of CVID. Genetic defects damping different B cell developmental stages can alter B- and even other lymphocytes' differentiation and might be involved in the clinical and immunologic presentations of the disorder. Reports concerning T and B cell abnormalities have been published in CVID patients, but such comprehensive data on monogenic CVID patients is few and no review article exists to describe the abrogation of lymphocyte subsets in these disorders. Hence, we aimed to review the role of altered B- and T-cell differentiation in the pathogenesis of CVID patients with monogenic defects.

Role of rare immune cells in common variable immunodeficiency.

Common variable immunodeficiency disorder (CVID) is a heterogeneous disorder and the most common symptomatic antibody deficiency disease characterized with hypogammaglobulinemia and a broad range of clinical manifestations. Multiple genetic, epigenetic, and immunological defects are involved in the pathogenesis of CVID. These immunological defects include abnormalities in the number and/or function of B lymphocytes, T lymphocytes, and other rare immune cells. Although some immune cells have a relatively lower proportion among total immune subsets in the human body, they could have important roles in the pathogenesis of immunological disorders like CVID. To the best of our knowledge, this is the first review that described the role of rare immune cells in the pathogenesis and clinical presentations of CVID.

Evaluation of Expression of LRBA and CTLA-4 Proteins in Common Variable Immunodeficiency Patients.

Common variable immunodeficiency (CVID) is a primary immunodeficiency disease with a heterogeneous genetic background. Lipopolysaccharide-responsive beige-like anchor (LRBA), as well as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), have important regulatory roles in the immune responses. Here, we have investigated the expression of LRBA and CTLA-4 proteins in CVID patients with at least one presentation of early-onset occurrence, autoimmunity, or enteropathy. In this study, 20 newly diagnosed CVID patients without infection only phenotype, and ten healthy individuals were enrolled. The expressions of LRBA and CTLA-4 proteins were assessed by western blotting and flow cytometry, respectively. The patients were divided into two groups of autoimmunity-positive (11 cases) and autoimmunity-negative (9 patients). LRBA and CTLA-4 expressions were significantly lower in autoimmune-positive patients than in healthy individuals (P = .03 and P = .03, respectively). Autoimmune-negative patients had lower expression of LRBA and CTLA-4 than the control group, although it was not significant. There was a positive correlation between the expressions of LRBA and CTLA-4 in both groups of patients (P < .05). Furthermore, the highest frequency of LRBA (85.7%) and CTLA-4 (71.4%) defects was detected in those with concomitant presence of autoimmunity, enteropathy, and early-onset occurrence. Concurrent presence of autoimmunity, enteropathy, and early-onset occurrence in CVID patients could be indicative of a lack of expression in LRBA and CTLA-4 proteins. This could be helpful in early diagnosis and initiation of appropriate treatment in these patients prior to genetic confirmation.

The First Iranian Cohort of Pediatric Patients with Activated Phosphoinositide 3-Kinase-δ (PI3Kδ) Syndrome (APDS).

BACKGROUND: Activated phosphoinositide 3-kinase δ syndrome (APDS) is a recently defined combined primary immunodeficiency disease (PID) characterized by recurrent respiratory tract infections, lymphoproliferation, autoimmunity and lymphoma. Gain-of-function mutations in PIK3CD and loss-of-function of PIK3R1 genes lead to APDS1 and APDS2, respectively. METHODS: Demographic, clinical, immunological and genetic data were collected from medical records of 15 pediatric patients, who were genetically identified using the whole-exome sequencing method. RESULTS: Fifteen patients (6 APDS1 and 9 APDS2) were enrolled in this study. Recurrent respiratory tract infections followed by lymphoproliferation and autoimmunity were the most common manifestations (86.7%, 53.3% and 26.7%, respectively). Five patients (33.3%) had a Hyper-IgM-syndrome-like immunoglobulin profile. In the APDS1 group, splice site and missense mutations were found in half of the patients and the C-lobe domain of PIK3CD was the most affected region (50%). In the APDS2 group, splice site mutation was the most frequent mutation (77.8%) and the inter-SH2 domain was the most affected region of PIK3R1 (66.7%). Mortality rate was significantly higher in APDS2 group (P = .02) mainly due to chronic lung infections. CONCLUSION: Respiratory tract infections and humoral immunodeficiency are commonly the most important complication in pediatric APDS patients, and they can be fatal by ultimately causing catastrophic damage to the structure of lungs. Hence, physicians should be aware of its significance and further work-up of patients with recurrent respiratory tract infections especially in patients with lymphoproliferation. Moreover, delineation of genotype-phenotype associations with disease severity could be helpful in the timely application of appropriate management and patients' survival.

The First Case Report of Kabuki Syndrome from the National Iranian Registry of Primary Immunodeficiencies.

Kabuki syndrome is a rare congenital anomaly/mental retardation syndrome characterized by intellectual disability, developmental delay, short stature, facial dysmorphic features including ectropion of the lateral third of the lower eyelids, long palpebral fissures, and prominent finger pads. Pathogenic variants of KMT2D (MLL2) and KDM6A are found to be the major causes of Kabuki syndrome. Here, we report the first Iranian case with Kabuki syndrome with an IQ of 79, two episodes of viral pneumonia and distinctive facial features, prominent ears, and persistent fetal fingertip pads. These characteristics raised our suspicion of performing whole-exome sequencing (WES), which revealed 2 heterozygous pathogenic missense variants in the KMT2D gene: c.C10024T in exon 34, leading to p.R3342C and c.G15005A in exon 48, leading to p.R5002Q. Hence, the definitive diagnosis of Kabuki syndrome was made based on molecular findings along with the intellectual disability and characteristic facial features.

Evaluation of Radiation Sensitivity in Patients with Hyper IgM Syndrome.

BACKGROUND: HIGM syndrome is a rare form of primary immunodeficiencies characterized by normal/increased amounts of serum IgM and decreased serum levels of other switched immunoglobulin classes. Since the affected patients are continuously infected with various types of pathogens and are susceptible for cancers, diagnostic and therapeutic tests including imaging techniques are recommended for the diagnosis and treatment of these patients, which predispose them to higher accumulated doses of radiation. Given the evidence of class switching recombination machinery defect and its association with an increased rate of DNA repair, we aimed to evaluate radiation sensitivity among a group of patients diagnosed with HIGM syndrome. METHODS: 19 HIGM patients (14 CD40 L and 3 AID deficiencies and 2 unsolved cases without known genetic defects) and 17 control subjects (10 healthy subjects as negative control group, 7 ataxia-telangiectasia patients as positive control group) were enrolled. G2 assay was carried out for the determination of radiosensitivity. RESULTS: Based on radiation-induced chromosomal changes among the studied HIGM patients and their comparison with the controls, almost all (95%) the patients had degrees of radiosensitivity: 6 patients with low to moderate, 1 patient with moderate, 11 patients with severe and 1 patient without radiation sensitivity. CONCLUSION: Today, X-ray radiation plays a very important role in diagnostic and therapeutic procedures; while increased exposure has devastating effects especially in radiosensitive patients. Considering higher sensitivity in HIGM patients, utilizing radiation-free techniques could partly avoid unnecessary and high-level exposure to radiation, thus preventing or reducing its harmful effects on the affected patients.

Evaluation of respiratory complications in patients with X-linked and autosomal recessive agammaglobulinemia.

BACKGROUND: Congenital agammaglobulinemia is the first primary immunodeficiency disorder characterized by a defect in B lymphocyte development and subsequently decreased immunoglobulin levels. These patients are prone to suffer from recurrent infections mostly involving the respiratory tract. In this study, we aimed to describe in detail respiratory tract complications as the most prominent clinical feature among agammaglobulinemic patients. METHODS: A total number of 115 patients were included. Demographic, clinical, and genetic data were collected from the patients' medical records. Among the available patients, pulmonary function tests (PFTs) and/or high-resolution computed tomography (HRCT) were performed. RESULTS: Respiratory tract complications (85.2%) especially pneumonia (62.6%) were the most prominent clinical features in our cohort. Among patients with abnormal PFT results (N = 19), a mixed respiratory pattern was observed in 36.8%. HRCT was carried out in 29 patients; Bhalla scoring-based evaluation of these patients indicated excellent (44.8%), followed by good (34.5%) and mild (20.7%) results. Bronchiectasis was found in 13 patients undergoing HRCT (44.8%). We found significant inverse correlations between the Bhalla score and incidence rate of pneumonia, as well as the presence of bronchiectasis. Patients with abnormal PFT results had statistically significant higher bronchiectasis frequency and lower Bhalla scores compared to those with normal results. Forty-one patients were deceased, and here, respiratory failure was the most common cause of death (45.5%). CONCLUSION: High prevalence of respiratory tract infections among agammaglobulinemic patients and subsequent progression to permanent lung damage highlights the importance of implementing respiratory evaluation as part of routine follow-up program of agammaglobulinemic patients. Physicians should be aware of this and regularly monitor the respiratory function of these patients to allow for timely diagnosis and treatment initiation aiming to improve patients' prognosis and quality of life.

Primary Immunodeficiency Diseases and Bacillus Calmette-Guérin (BCG)-Vaccine-Derived Complications: A Systematic Review.

BACKGROUND: Bacillus Calmette-Guérin (BCG) vaccine is a live attenuated bacterial vaccine derived from Mycobacterium bovis, which is mostly administered to neonates in regions where tuberculosis is endemic. Adverse reactions after BCG vaccination are rare; however, immunocompromised individuals and in particular patients with primary immunodeficiencies (PIDs) are prone to develop vaccine-derived complications. OBJECTIVE: To systematically review demographic, clinical, immunologic, and genetic data of PIDs that present with BCG vaccine complications. Moreover, we performed a meta-analysis aiming to determine the BCG-vaccine complications rate for patients with PID. METHODS: We conducted electronic searches on Embase, Web of Science, PubMed, and Scopus (1966 to September 2018) introducing terms related to PIDs, BCG vaccination, and BCG vaccine complications. Studies with human subjects with confirmed PID, BCG vaccination history, and vaccine-associated complications (VACs) were included. RESULTS: A total of 46 PIDs associated with BCG-VAC were identified. Severe combined immunodeficiency was the most common (466 cases) and also showed the highest BCG-related mortality. Most BCG infection cases in patients with PID were reported from Iran (n = 219 [18.8%]). The overall frequency of BCG-VAC in the included 1691 PID cases was 41.5% (95% CI, 29.9-53.2; I2 = 98.3%), based on the results of the random-effect method used in this meta-analysis. Patients with Mendelian susceptibility to mycobacterial diseases had the highest frequency of BCG-VACs with a pooled frequency of 90.6% (95% CI, 79.7-1.0; I2 = 81.1%). CONCLUSIONS: Several PID entities are susceptible to BCG-VACs. Systemic neonatal PID screening programs may help to prevent a substantial amount of BCG vaccination complications.

Increased Expression of B Lymphocyte Induced Maturation Protein 1 (BLIMP1) in Patients with Common Variable Immunodeficiency (CVID).

Common variable immunodeficiency (CVID) is a primary immune deficiency disorder characterized by a failure in B cell differentiation, impaired immunoglobulin production,and defect in response to vaccines. As a result of defective B cell maturation and differentiation in CVID, the affected patients commonly present with reduced numbers of memory B cell and antibody-secreting plasma cells. B-cell lymphoma 6 protein (BCL6) and B lymphocyte induced maturation protein 1 (BLIMP1) molecules are two important transcription factors that have key roles in the maturation of B cells to plasma cells. Hence, in the current survey, we aimed to evaluate the mRNA and protein expression levels of BCL6 and BLIMP1 in B lymphocytes isolated from peripheral blood in CVID patients. We collected blood samples from 12 CVID patients and 12 healthy controls. We isolated peripheral blood mononuclear cells (PBMCs) using Ficoll density gradient separation. Then, CD19+ B cells were purified using MACS. The protein expression and transcriptional level of BCL6 and BLIMP1 were respectively measured using flow cytometry and real-time PCR. Our results showed that the BLIMP1 mRNA expression, as well as BLIMP1 protein expression, were significantly higher in CVID patients compared to control subjects (p=0.009 and p=0.007, respectively). However, we found no significant difference in mRNA and protein expression of BCL6 between patients and healthy controls. According to our findings, increased mRNA and protein expression levels of BLIMP1 could be involved in defective maturation of B cells in patients with CVID and elucidate mechanistic insights into the pathogenesis of this disorder.

The evaluation of neutropenia in common variable immune deficiency patients.

Objectives: Common variable immunodeficiency is a primary immunodeficiency disease characterized by hypogammaglobulinemia and heterogeneous clinical features. Neutropenia is a rare complication among CVID patients leading to a higher rate of infections and morbidity. Multiple factors (e.g. autoimmunity, infections, drugs and etc.) are found to underlie this complication.Methods: In the present study, demographic, clinical and laboratory data were compared between two groups of CVID patients with and without neutropenia.Results: Frequency of neutropenia was 8.1%. Infectious complications were the most prevalent clinical manifestations regardless of presence of neutropenia. However, candida infection and septicemia were significantly higher in neutropenic patients (p = 0.001 and p = 0.01, respectively). The most prominent clinical phenotypes of CVID patients with neutropenia were polyclonal lymphocytic infiltration and autoimmunity, both being considerably higher compared to the non-neutropenic group (p = 0.04 and p = 0.009, respectively). The mortality rate in neutropenic patients was higher than in patients without neutropenia (61.1 vs. 25.2%, p = 0.004).Conclusion: Although neutropenia is a rare complication among CVID patients, it is associated with frequent and severe clinical complications, including autoimmunity and lymphoproliferative conditions. Also, its accompaniment with higher mortality frequency in CVID patients indicates a need for more precise attention and consideration regarding specific treatment in neutropenic patients.

Potential role of regulatory B cells in immunological diseases.

Regulatory B cells (Bregs) are immune-modulating cells that affect the immune system by producing cytokines or cellular interactions. These cells have immunomodulatory effects on the immune system by cytokine production. The abnormalities in Bregs could be involved in various disorders such as autoimmunity, chronic infectious disease, malignancies, allergies, and primary immunodeficiencies are immune-related scenarios. Ongoing investigation could disclose the biology and the exact phenotype of these cells and also the assigned mechanisms of action of each subset, as a result, potential therapeutic strategies for treating immune-related anomalies. In this review, we collect the findings of human and mouse Bregs and the therapeutic efforts to change the pathogenicity of these cells in diverse disease.

Clinical Manifestations, Immunological Characteristics and Genetic Analysis of Patients with Hyper-Immunoglobulin M Syndrome in Iran.

BACKGROUND: Hyper-immunoglobulin M (HIGM) syndrome is a rare heterogeneous group of primary immunodeficiency disorders characterized by low or absent serum levels of IgG and IgA along with normal or elevated serum levels of IgM. METHODS: Clinical and immunological data were collected from the 75 patients' medical records diagnosed in Children's Medical Center affiliated to Tehran University Medical Sciences and other Universities of Medical Sciences in Iran. Among 75 selected patients, 48 patients (64%) were analyzed genetically using targeted and whole-exome sequencing. RESULTS: The ratio of male to female was 2.9:1. The median age at the onset of the disease, time of diagnosis, and diagnostic delay were 10.5, 50, and 24 months, respectively. Pneumonia and lower respiratory tract infections (61.3%) were the most common complications. Responsible genes were identified in 35 patients (72.9%) out 48 genetically analyzed patients. Cluster of differentiation 40 ligand gene was the most mutated gene observed in 24 patients (68.5%) followed by activation-induced cytidine deaminase gene in 7 patients, lipopolysaccharide-responsive and beige-like anchor (1 patient), nuclear factor-kappa-B essential modulator (1 patient), phosphoinositide-3-kinase regulatory subunit 1 (1 patient), and nuclear factor kappa B subunit 1 (1 patient) genes. Nineteen (25.3%) patients died during the study period, and pneumonia was the major cause of death occurred in 6 (31.6%) patients. CONCLUSION: Physicians in our country should carefully pay attention to respiratory tract infections and pneumonia, particularly in patients with a positive family history. Further investigations are required for detection of new genes and pathways resulting in HIGM phenotype.

The First Purine Nucleoside Phosphorylase Deficiency Patient Resembling IgA Deficiency and a Review of the Literature.

Purine nucleoside phosphorylase (PNP) deficiency is a rare autosomal recessive primary immunodeficiency disorder characterized by decreased numbers of T-cells, variable B-cell abnormalities, decreased amount of serum uric acid and PNP enzyme activity. The affected patients usually present with recurrent infections, neurological dysfunction and autoimmune phenomena. In this study, whole-exome sequencing was used to detect mutation in the case suspected of having primary immunodeficiency. We found a homozygous mutation in PNP gene in a girl who is the third case from the national Iranian registry. She had combined immunodeficiency, autoimmune hemolytic anemia and a history of recurrent infections. She developed no neurological dysfunction. She died at the age of 11 after a severe chicken pox infection. PNP deficiency should be considered in late-onset children with recurrent infections, autoimmune disorders without typical neurologic impairment.

PIK3R1 Mutation Associated with Hyper IgM (APDS2 Syndrome): A Case Report and Review of the Literature.

BACKGROUND AND OBJECTIVE: APDS [Activated phosphoinositide 3-kinase (PI3K) δ Syndrome] is a newly found special form of primary immunodeficiency caused by mutations in genes encoding PI3Kδ subunits and over-activation of the PI3K signaling pathway. Gain-of-function and loss-of-function mutations in PIK3CD (encoding P110δ) and PIK3R1 (encoding p85α, p55α and p50α) lead to APDS1 and APDS2, respectively. The subsequent irregular PI3K downstream signaling cascade is associated with abnormalities in B cells and T cells and the consequent heterogeneous clinical manifestations including respiratory tract infections, autoimmunity, lymphoproliferation and not to mention primary antibody deficiency. In this study, we report a 12-year-old girl with a mutation in the PIK3R1 gene who manifested immunological phenotypes resembling hyper IgM syndrome along with a review of the literature of the previously reported patients. METHODS: Whole exome sequencing was performed to detect the underlying genetic mutation in this patient. RESULTS: A de novo heterozygous splice site mutation in the hot spot of the PIK3R1 gene within the intron 10 was found (c.1425+1G>A). CONCLUSION: Further investigations are required for evaluation of the underlying genetic defects and the possible associations between genetic underpinning and heterogeneous severity and features of the disease.

G2-lymphocyte chromosomal radiosensitivity in patients with LPS responsive beige-like anchor protein (LRBA) deficiency.

Lipopolysaccharide-responsive, beige-like anchor protein (LRBA) deficiency is an autosomal recessive primary immunodeficiency disease characterized by a CVID-like phenotype, particularly severe autoimmunity and inflammatory bowel disease. This study was undertaken to evaluate radiation sensitivity in 11 LRBA-deficient patients. Therefore, stimulated lymphocytes of the studied subjects were exposed to a low dose γ-radiation (100 cGy) in the G2 phase of the cell cycle and chromosomal aberrations were scored. Lymphocytes of age-sex matched healthy individuals used in the same way as controls. Based on the G2-assay, six (54.5%) of the patients had higher radiosensitivity score comparing to the healthy control group, forming the radiosensitive LRBA-deficient patients. This chromosomal radiosensitivity showed that these patients are predisposed to autoimmunity and/or malignancy, and should be protected from unnecessary diagnostic and therapeutic procedures using ionizing radiation and exposure to other DNA damaging agents.

The hyper IgM syndromes: Epidemiology, pathogenesis, clinical manifestations, diagnosis and management.

Hyper Immunoglobulin M syndrome (HIGM) is a rare primary immunodeficiency disorder characterized by low or absent levels of serum IgG, IgA, IgE and normal or increased levels of serum IgM. Various X-linked and autosomal recessive/dominant mutations have been reported as the underlying cause of the disease. Based on the underlying genetic defect, the affected patients present a variety of clinical manifestations including pulmonary and gastrointestinal complications, autoimmune disorders, hematologic abnormalities, lymphoproliferation and malignancies which could be controlled by multiple relevant therapeutic approaches. Herein, the epidemiology, pathogenesis, clinical manifestations, diagnosis, management, prognosis and treatment in patients with HIGM syndrome have been reviewed.