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Background and Purpose: Mechanisms behind hypogammaglobulinaemia during rituximab treatment are poorly understood., Methods: In this register-based multi-centre retrospective cohort study of multiple sclerosis (MS) patients in Sweden, 2745 patients from six participating Swedish MS centres were identified via the Swedish MS registry and included between 14 March 2008 and 25 January 2021. The exposure was treatment with at least one dose of rituximab for MS or clinically isolated syndrome, including data on treatment duration and doses. The degree of yearly decrease in immunoglobulin G (IgG) and immunoglobulin M (IgM) levels was evaluated., Results: The mean decrease in IgG was 0.27 (95% confidence interval 0.17-0.36) g/L per year on rituximab treatment, slightly less in older patients, and without significant difference between sexes. IgG or IgM below the lower limit of normal (<6.7 or <0.27 g/L) was observed in 8.8% and 8.3% of patients, respectively, as nadir measurements. Six out of 2745 patients (0.2%) developed severe hypogammaglobulinaemia (IgG below 4.0 g/L) during the study period. Time on rituximab and accumulated dose were the main predictors for IgG decrease. Previous treatment with fingolimod and natalizumab, but not teriflunomide, dimethyl fumarate, interferons or glatiramer acetate, were significantly associated with lower baseline IgG levels by 0.80-1.03 g/L, compared with treatment-naïve patients. Switching from dimethyl fumarate or interferons was associated with an additional IgG decline of 0.14-0.19 g/L per year, compared to untreated., Conclusions: Accumulated dose and time on rituximab treatment are associated with a modest but significant decline in immunoglobulin levels. Previous MS therapies may influence additional IgG decline., (© 2024 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

Propionate defects (PDs) mainly include methylmalonic (MMA) and propionic acidemia (PA) defects. Lifelong PD patients progress from the compensated to the decompensated stages, the latter of which are characterized by life-threatening acidemia and hyperammonemia crises. PD patients can suffer immunocompromise, especially during the decompensation stage. There is a significant gap in the research regarding the humoral immune response in PD patients. Here, we analyzed serum immunoglobulin concentrations and hemograms across compensated and decompensated stages in PD patients. Nutritional status and crisis triggers of decompensation were also explored. Twenty patients were studied, and 25 decompensation events (DE) and 8 compensation events (CE) were recorded. Compared with those in the CE group, the IgG levels in the DE group (513.4 ± 244.5 mg/dL) were significantly lower than those in the CE group (860.8 ± 456.5 mg/dL) ( p < 0.0087). The mean hemoglobin concentration was significantly lower in the DE group (11.8 g/dL) than in the CE group (13.4 g/dL) ( p < 0.05). The most frequent (48%) possible decompensation trigger factor was infection. Most of the events were registered in eutrophic patients (87.9%), despite which 65.2% and 50% of patients who experienced decompensated and compensated events, respectively, presented with hypogammaglobulinemia G. These findings provide evidence of the immunodeficiency of PD patients, independent of their nutritional status. We suggest that PD patients be managed as immunocompromised independently of their nutritional status or metabolic state (compensated or decompensated).

Introduction: Kidney transplant recipients often experience significant alterations in their immune system, which can lead to increased susceptibility to infections. This study aimed to analyze time-dependent changes in serum immunoglobulin and complement levels and determine the risk factors associated with infection., Methods: A retrospective analysis of serum samples from 192 kidney transplant recipients who received transplantations between August 2016 and December 2019 was conducted. The serum samples were obtained at preoperative baseline (T0), postoperative 2 weeks (T1), 3 months (T2), and 1 year (T3). The levels of serum C3, C4, IgG, IgA, and IgM were measured to evaluate immune status over time., Results: The analysis revealed significant decreases in IgG and IgA levels at T1. This period was associated with the highest occurrence of hypogammaglobulinemia (HGG) and hypocomplementemia (HCC), as well as an increased incidence of severe infection requiring hospitalization and graft-related viral infections. Using a time-dependent Cox proportional hazards model adjusted for time-varying confounders, HGG was significantly associated with an increased risk of infection requiring hospitalization (HR, 1.895; 95% CI: 1.871-1.920, P-value<0.001) and graft-related viral infection (HR, 1.152; 95% CI: 1.144-1.160, P-value<0.001)., Discussion: The findings suggest that monitoring serum immunoglobulin levels post-transplant provides valuable insights into the degree of immunosuppression. Hypogammaglobulinemia during the early post-transplant period emerges as a critical risk factor for infection, indicating that serum immunoglobulins could serve as feasible biomarkers for assessing infection risk in kidney transplant recipients., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Jo, Min, Jo, Han, Ha, Song, Lee and Kim.)

Rituximab (RTX) is an anti-CD20 monoclonal antibody that targets B cells-from the immature pre-B-cell stage in the bone marrow to mature circulating B cells-while preserving stem cells and plasma cells. It is used to treat autoimmune diseases, hematological malignancies, or complications after hematopoietic stem cell transplantation (HSCT). Its safety profile is acceptable; however, a subset of patients can develop persistent hypogammaglobulinemia and associated severe complications, especially in pediatric populations. We report the unrelated cases of two young men aged 17 and 22, presenting with persistent hypogammaglobulinemia more than 7 and 10 years after treatment with RTX, respectively, and administered after HSCT for hemolytic anemia and Epstein-Barr virus reactivation, respectively. Both patients' immunological workups showed low levels of total immunoglobulin, vaccine antibodies, and class switched-memory B cells but an increase in naive B cells, which can also be observed in primary immunodeficiencies such as those making up common variable immunodeficiency. Whole exome sequencing for one of the patients failed to detect a pathogenic variant causing a Mendelian immunological disorder. Annual assessments involving interruption of immunoglobulin replacement therapy each summer failed to demonstrate the recovery of endogenous immunoglobulin production or normal numbers of class switched-memory B cells 7 and 10 years after the patients' respective treatments with RTX. Although the factors that may lead to prolonged hypogammaglobulinemia after rituximab treatment (if necessary) remain unclear, a comprehensive immunological workup before treatment and long-term follow-up are mandatory to assess long-term complications, especially in children., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Luterbacher, Bernard, Baleydier, Ranza, Jandus and Blanchard-Rohner.)

Background and Objectives: To determine the frequency of hypogammaglobulinemia and infections in patients with multiple sclerosis (PwMS) receiving rituximab (RTX)., Methods: This prospective observational study included all consecutive PwMS receiving RTX at the university hospital of Marseille, France, between 2015 and 2020. Patient visits occurred at least every 6 months., Results: We included 188 patients (151 with relapsing-remitting MS; the mean age was 43.4 years [SD 12.9], median disease duration 10 years [range 0-36], median Expanded Disability Status Scale 5 [range 0-8], median follow-up 3.5 years [range 1-5.8], and median number of RTX infusions 5 [range 1-9]). Overall, 317 symptomatic infections and 13 severe infections occurred in 133 of 188 (70.7%) and 11 of 188 (5.9%) patients, respectively. After 4 years, 24.4% of patients (95% CI 18.0-33.1) were free of any infection and 92.0% (95% CI 87.1-97.1) had not experienced a severe infection. At RTX onset, the immunoglobulin G (IgG) level was abnormal in 32 of 188 (17%) patients. After RTX, IgG level was <7, <6, <4 and <2 g/L for 83 (44%), 44 (23.4%), 8 (4.2%) and 1 (0.53%) patients, respectively. The risk of infection was associated with reduced IgG levels (multivariate Cox proportional hazards hazard ratio [HR] = 0.86, 95% CI 0.75-0.98, p = 0.03). The risk of reduced IgG level <6 g/L increased with age (HR = 1.36, 95% CI 1.05-1.75, p = 0.01)., Discussion: In PwMS receiving RTX, reduced IgG level was frequent and interacted with the risk of infection., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Common variable immunodeficiency (CVID) is characterized by profound primary antibody defects and frequent infections, yet autoimmune/inflammatory complications of unclear origin occur in 50% of individuals and lead to increased mortality. Here, we show that circulating bacterial 16S rDNA belonging to gut commensals was significantly increased in CVID serum (P < 0.0001), especially in patients with inflammatory manifestations (P = 0.0007). Levels of serum bacterial DNA were associated with parameters of systemic immune activation, increased serum IFN-γ, and the lowest numbers of isotype-switched memory B cells. Bacterial DNA was bioactive in vitro and induced robust host IFN-γ responses, especially among patients with CVID with inflammatory manifestations. Patients with X-linked agammaglobulinemia (Bruton tyrosine kinase [BTK] deficiency) also had increased circulating bacterial 16S rDNA but did not exhibit prominent immune activation, suggesting that BTK may be a host modifier, dampening immune responses to microbial translocation. These data reveal a mechanism for chronic immune activation in CVID and potential therapeutic strategies to modify the clinical outcomes of this disease.

Deficiency of adenosine deaminase 2 (DADA2) is a rare autosomal recessive disease caused by loss-of-function variants in the ADA2 gene. DADA2 typically presents in childhood and is characterized by vasculopathy, stroke, inflammation, immunodeficiency, as well as hematologic manifestations. ADA2 protein is predominantly present in stimulated monocytes, dendritic cells, and macrophages. To elucidate molecular mechanisms in DADA2, CD14 + monocytes from 14 patients and 6 healthy donors were analyzed using single-cell RNA sequencing (scRNA-seq). Monocytes were purified by positive selection based on CD14 expression. Subpopulations were imputed from their transcriptomes. Based on scRNA-seq, monocytes could be classified as classical, intermediate, and nonclassical. Further, we used gene pathway analytics to interpret patterns of up- and down-regulated gene transcription. In DADA2, the frequency of nonclassical monocytes was higher compared with that of healthy donors, and M1 macrophage markers were up-regulated in patients. By comparing gene expression of each monocyte subtype between patients and healthy donors, we identified upregulated immune response pathways, including IFNα/β and IFNγ signaling, in all monocyte subtypes. Distinctively, the TNFR2 noncanonical NF-κB pathway was up-regulated only in nonclassical monocytes. Patients' plasma showed increased IFNγ and TNFα levels. Our results suggest that elevated IFNγ activates cell signaling, leading to differentiation into M1 macrophages from monocytes and release of TNFα. Immune responses and more general response to stimuli pathways were up-regulated in DADA2 monocytes, and protein synthesis pathways were down-regulated, perhaps as stress responses. Our identification of novel aberrant immune pathways has implications for therapeutic approaches in DADA2 (registered at clinicaltrials.gov NCT00071045)., (Published 2021. This article is a U.S. Government work and is in the public domain in the USA.)

BACKGROUND Infections are the main cause of mortality and morbidity in multiple myeloma (MM) patients. However, adult immunodeficiency specialists in China are lacking, and the care of secondary immunodeficiency (SID) and the prognostic role of hypogammaglobulinemia in MM is unknown. MATERIAL AND METHODS MM patients (295) were retrospectively analyzed between January 2012 and 2020 in Zhejiang Provincial People's Hospital, Hangzhou Medical College. MM patients with immunoglobulin (Ig) G <5 g/L were defined as SID patients. The care of these patients and the prognostic role of IgG <5 g/L were analyzed RESULTS Forty-five of 295 MM patients with IgG <5 g/L were defined as SID patients. These 45 patients mainly had recurrent infections, especially pulmonary bacterial infections; 2 patients had them 5 times/year. The median survival time was significantly shorter in MM patients with SID (24 vs 66 months). More importantly, the multivariate and univariate analysis revealed that IgG <5 g/L was an independent prognostic factor for MM patients. CONCLUSIONS Ig replacement therapy or prophylactic antibiotics for MM patients with SID were lacking in this single retrospective study. IgG <5 g/L could be a prognostic marker for MM patients.

Introduction and Objectives: X-linked agammaglobulinemia (XLA), the first known primary immunodeficiency, is caused by rare mutations in Bruton's tyrosine kinase (BTK) gene. Mutations in the BTK gene lead to a failure in the development and maturation of B-cell linage. A decreased number of B-cells results in agammaglobulinemia and increased susceptibility to a variety of infections. Therefore, patients with XLA usually manifest with repetitive bacterial infections, such as upper respiratory tract infections, septic arthritis, osteomyelitis, and urinary tract infections, since their infancy., Patients: We report a 17-year-old Iranian boy with XLA, referred to us with a history of severe and recurrent episodes of bacterial infections for a period of six years., Results: Genetic analysis using the whole Exome sequencing revealed a hemizygous missense mutation in the BTK gene (c.428 A > T, p.His143Leu)., Conclusion: To our knowledge, c.428 A > T has not been reported in the BTK gene.

Background: Novel immunodiagnostic markers are required in order to discriminate between mild hypogammaglobulinemia and severe humoral primary immune deficiencies in children. The efficacy of an antibody response to infections and vaccines is underpinned by T follicular helper (Tfh) cells, activating an immunoglobulin class switch recombination, somatic hypermutations, and affinity maturation., Objective: To determine the formation of the Tfh cells in antibody deficient children and to define their importance as prognostic markers helpful in defining the severity of hypogammaglobulinemia., Methods: We retrospectively reviewed medical records of 200 children aged from 2 months to 10 years, in whom hypogammaglobulinemia was assessed, from January to December 2019. In all the children studied, a flow cytometric analysis of the Tfh cell compartment was performed., Results: In young infants aged from 2 to 9 months, the mean relative frequency of the Tfh population was lower than in the control population. Concomitantly, the relative values of Tfh cells, corresponding with the 95th percentile, were below the reference values in all age groups., Conclusions: A deficiency of Tfh cells in young infants mirrors the immaturity of the humoral immune response, whereas in older children Tfh cells are proposed as a prognostic marker facilitating to distinguish between mild hypogammaglobulinemia and the developing common variable immunodeficiency.

Bacterial respiratory tract infections are the hallmark of primary antibody deficiencies (PADs). Because they are also among the most common infections in healthy individuals, PADs are usually overlooked in these patients. Careful evaluation of the history, including frequency, chronicity, and presence of other infections, would help suspect PADs. This review will focus on infections in relatively common PADs, discussing diagnostic challenges, and some management strategies to prevent infections., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Demirdag and Gupta.)

A 24-year-old woman with a medical history of chronic lower extremity oedema, abdominal pain, diarrhoea and recurrent pulmonary infections presented with sepsis from right lower extremity cellulitis. Blood cultures grew Morganella morganii Laboratory evaluation revealed lymphopaenia, hypogammaglobulinaemia, a low CD4+ T-cell count and nutritional deficiencies resulting from protein-losing enteropathy (PLE). CT showed small bowel wall thickening in the jejunum and ileum. Primary intestinal lymphangiectasia (PIL) was the likely diagnosis that explained her PLE and immunodeficiencies. Video capsule endoscopy is an important diagnostic tool for distal small bowel pathology and confirmed patchy areas of lymphangiectasia of the jejunum and ileum. Secondary causes of lymphangiectasia were ruled out. Clinically significant immunodeficiency from PIL has not been frequently documented, and this case adds to the literature of rare infections associated with PIL. Treatment with intravenous antibiotics resolved her septicaemia, while dietary modifications improved her oedema, abdominal pain and diarrhoea., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

The absence of adenosine deaminase (ADA) causes severe combined immune deficiency (SCID), which has been treated with PEGylated bovine-extracted ADA (ADAGEN). ADAGEN was recently replaced by a PEGylated recombinant bovine ADA, expressed in Escherichia coli (elapegademase, ELA-ADA). Limited information on ELA-ADA is available.  ADA enzymatic activity of ELA-ADA and ADAGEN was assessed in vitro at diverse dilutions. ADA activity and immune reconstitution in an ADA-SCID patient treated with ELA-ADA were compared with age-matched patients previously treated with ADAGEN. ADA activity and thymus reconstitution were evaluated in ADA-deficient mice following ELA-ADA or ADAGEN administered from 7 days postpartum. In vitro, ADA activity of ELA-ADA and ADAGEN were similar at all dilutions. In an ADA-SCID patient, ELA-ADA treatment led to a marked increase in trough plasma ADA activity, which was 20% higher than in a patient previously treated with ADAGEN. A marked increase in T cell numbers and generation of naive T cells was evident following 3 months of ELA-ADA treatment, while T cell numbers increased following 4 months in 3 patients previously treated with ADAGEN. T cell proliferations stimulation normalized and thymus shadow became evident following ELA-ADA treatment. ADA activity was significantly increased in the blood of ADA-deficient mice following ELA-ADA compared to ADAGEN, while both treatments improved the mice weights, the weight, number of cells in their thymus and thymocyte subpopulations. ELA-ADA has similar in- vitro and possibly better in-vivo activity than ADAGEN. Future studies will determine whether ELA-ADA results in improved long-term immune reconstitution., (© 2020 British Society for Immunology.)

Background: We report the first case of a family with co-occurrence of Wilson disease (WD), an autosomal recessive disorder of copper metabolism, and X-linked agammaglobulinemia (XLA), a primary immunodeficiency disorder (PIDD) that features marked reduction in circulating B lymphocytes and serum immunoglobulins., Methods and Results: Through utilization of a multiplexed biomarker peptide quantification method known as the immuno-SRM assay, we were able to simultaneously and independently identify which family members are affected with WD and which are affected with XLA using dried blood spots (DBS)., Conclusion: Being able to delineate multiple diagnoses using proteolytic analysis from a single DBS provides support for implementation of this methodology for clinical diagnostic use as well as large-scale population screening, such as newborn screening (NBS). This could allow for early identification and treatment of affected individuals with WD or XLA, which have been shown to reduce morbidity and decrease mortality in these two populations., (© 2020 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.)

Individuals affected with autosomal recessive cutis laxa type 2B and 3 usually show translucent skin with visible veins and abnormal elastic fibers, intrauterine and/or postnatal growth restriction and a typical triangular facial gestalt. Here we describe three unrelated individuals in whom such a cutis laxa syndrome was suspected, especially after electron microscopy revealed immature and less dense dermal elastic fibers in one of them. However, one of these children also displayed optic atrophy and two hypogammaglobulinemia. All had elevated liver enzymes and acute liver failure during febrile episodes leading to early demise in two of them. The only surviving patient had been treated with immunoglobulins. Through exome sequencing we identified mutations in NBAS, coding for a protein involved in Golgi-to-ER transport. NBAS deficiency causes several rare conditions ranging from isolated recurrent acute liver failure to a multisystem disorder mainly characterized by short stature, optic nerve atrophy and Pelger-Huët anomaly (SOPH). Since we subsequently verified Pelger-Huët anomaly in two of the patients the diagnosis SOPH syndrome was unequivocally proven. Our data show that SOPH syndrome can be regarded as a differential diagnosis for the progeroid forms of cutis laxa in early infancy and that possibly treatment of the hypogammaglobulinemia can be of high relevance for the prognosis.

Background: Patients with X-linked agammaglobulinemia (XLA) are protected against invasive bacterial infections due to IgG replacement therapy, but are still at higher risk for mucosal infections of the gut and respiratory tract. This might be explained by to the lack of IgA and IgM, as these antibodies are especially important for protection against invading bacterial pathogens on the mucosal surface., Methods: In an attempt to eliminate a chronic norovirus infection in a patient with X-linked agammaglobulinemia, fresh frozen plasma (FFP) was given two times a week for 3 weeks. At each visit, pre- and post-FFP infusion serum and saliva was collected to determine IgG-, IgA- and IgM-concentrations and serum half-life was calculated. Functionality of the immunoglobulins pre- and post-FFP infusion in both serum and saliva was tested by measuring complement activation, agglutination and killing of non-typeable Haemophilus influenzae (NTHi)., Results: Administration of FFP failed to eradicate the chronic norovirus infection. Serum IgA and IgM half-life was 4.2 ± 0.3 and 3.8 ± 0.3 days, respectively. The presence of serum IgM was associated with increased complement binding and complement-mediated killing of NTHi. IgA in saliva was detectable post-FFP and was associated with increased agglutination of NTHi. IgM in saliva was not detectable., Conclusions: We conclude that FFP treatment, although ineffective in clearing a chronic norovirus infection in this single patient, might be beneficial to prevent or eliminate bacterial infections in XLA patients by increasing IgM dependent complement-mediated killing in serum and IgA dependent bacterial agglutination on the mucosal surface.

Common variable immune deficiency (CVID) is a primary immunodeficiency disease, characterized by hypogammaglobulinemia, recurrent infections and various complications. The clinical heterogeneity of CVID has hindered identification of an underlying immune defect; diagnosis relies on clinical judgement, alongside evidence-based criteria. The lack of pathognomonic clinical or laboratory features leads to average diagnostic delays of 5 years or more from the onset. Vibrational spectroscopic techniques such as Fourier-transform infrared (FTIR) spectroscopy have recently gained increasing clinical importance, being rapid-, non-invasive and inexpensive methods to obtain information on the content of biological samples. This has led us to apply FTIR spectroscopy to the investigation of blood samples from a cohort of CVID patients; revealing spectral features capable of stratifying CVID patients from healthy controls with sensitivities and specificities of 97% and 93%, respectively for serum, and 94% and 95%, respectively for plasma. Furthermore we identified several discriminating spectral biomarkers; wavenumbers in regions indicative of nucleic acids (984 cm -1 , 1053 cm -1 , 1084 cm -1 , 1115 cm -1 , 1528 cm -1 , 1639 cm -1 ), and a collagen-associated biomarker (1528 cm -1 ), which may represent future candidate biomarkers and provide new knowledge on the aetiology of CVID. This proof-of-concept study provides a basis for developing a novel diagnostic tool for CVID.

We report a case of an 82-year-old woman who presented with a 2-week history of a left labial lump. She had a history of chronic lymphocytic leukaemia (CLL) for several years and remained stable without clinical evidence of disease progression. She was observed with regular blood tests and clinical assessment. She was hypogammaglobulinaemic from the CLL and due to frequent symptomatic infections requiring hospitalisation, was commenced on monthly intravenous immunoglobulin. A tissue biopsy of the labial lump confirmed involved CLL in the genital area and further investigations and management followed., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Ibrutinib and acalabrutinib are irreversible inhibitors of Bruton tyrosine kinase used in the treatment of B-cell malignancies. They bind irreversibly to cysteine 481 of Bruton tyrosine kinase, blocking autophosphorylation on tyrosine 223 and phosphorylation of downstream substrates including phospholipase C-γ2. In the present study, we demonstrate that concentrations of ibrutinib and acalabrutinib that block Bruton tyrosine kinase activity, as shown by loss of phosphorylation at tyrosine 223 and phospholipase C-γ2, delay but do not block aggregation in response to a maximally-effective concentration of collagen-related peptide or collagen. In contrast, 10- to 20-fold higher concentrations of ibrutinib or acalabrutinib block platelet aggregation in response to glycoprotein VI agonists. Ex vivo studies on patients treated with ibrutinib, but not acalabrutinib, showed a reduction of platelet aggregation in response to collagen-related peptide indicating that the clinical dose of ibrutinib but not acalabrutinib is supramaximal for Bruton tyrosine kinase blockade. Unexpectedly, low concentrations of ibrutinib inhibited aggregation in response to collagen-related peptide in patients deficient in Bruton tyrosine kinase. The increased bleeding seen with ibrutinib over acalabrutinib is due to off-target actions of ibrutinib that occur because of unfavorable pharmacodynamics., (Copyright© 2018 Ferrata Storti Foundation.)

Background: Most patients with primary antibody deficiency (PAD) suffer from less well-described and understood forms of hypogammaglobulinemia (unclassified primary antibody deficiency, unPAD). Because of the moderately decreased immunoglobulin levels compared to CVID, unPAD is generally considered to be clinically mild and not very relevant. Objective: To describe our cohort of-mainly-unPAD patients, and to analyze whether subgroups can be identified. Methods: Data were prospectively collected (February-2012 to June-2016) as part of a standardized, 1-day Care Pathway for suspected primary immunodeficiency. The TNO-AZL Questionnaire for Health-Related Quality of Life (HRQoL) was part of the pre-first-visit intake procedure. Results: Three hundred and twenty patients were referred to the Care Pathway. Data from 23/27 children and 99/113 adults who were diagnosed with PAD and gave informed consent were available for analysis. 89/99 adults had unPAD, the majority (74%) were female and 44% already showed bronchiectasis. HRQoL was significantly decreased in all domains, meaning that a lot of unPAD patients had to cope simultaneously with pain, negative feelings and impairments in cognition, home management tasks, sleep, social interaction, and work. The most prominently impaired HRQoL domain was vitality, indicating these patients feel extremely tired and worn out. Conclusion: These results highlight the need for more attention to the potential patient burden of unPADs. A larger cohort is needed to increase our understanding of unPADs and to analyze whether distinct subgroups can be identified. For now, it is important for the clinician to acknowledge the existence of unPAD and be aware of its potential consequences, in order to timely and appropriately manage its effects and complications.

Transcription factor (TF) networks determine cell fate in hematopoiesis. However, how TFs cooperate with other regulatory mechanisms to instruct transcription remains poorly understood. Here we show that in small pre-B cells, the lineage restricted epigenetic reader BRWD1 closes early development enhancers and opens the enhancers of late B lymphopoiesis to TF binding. BRWD1 regulates over 7000 genes to repress proliferative and induce differentiation programs. However, BRWD1 does not regulate the expression of TFs required for B lymphopoiesis. Hypogammaglobulinemia patients with BRWD1 mutations have B-cell transcriptional profiles and enhancer landscapes similar to those observed in Brwd1 -/- mice. These data indicate that, in both mice and humans, BRWD1 is a master orchestrator of enhancer accessibility that cooperates with TF networks to drive late B-cell development.

Aim: The aim of the study was to characterize quantitative and qualitative immunoglobulinopathies in patients with AITL at the onset of the disease., Materials and Methods: 55 patients with newly diagnosed AITL were enrolled in the study, the male/female ratio was 30/25; median age was 61 (29-81) years. Diagnosis was based on standard WHO criteria. Immunochemical studies of blood serum included serum protein electrophoresis/immunofixation, nephelometric quantification of total immunoglobulins, serum free light chain assay., Results: Quantitative and qualitative immunoglobulinopathies were determined in 49 (89,1%) of 55 pts. Quantitative immunoglobulinopathies were revealed in 47 (85.5%) of 55 cases, qualitative - in 14 (25,5%). Combination quantitative and qualitative immunoglobulinopathies was observed in 12 (21,8%) of 55 pts. The detected immunoglobulinopathies were divided into 4 groups: polyclonal hypergammaglobulinaemia, hypogammaglobulinaemia, oligoclonal gammapathy, and monoclonal gammapathy. Polyclonal hypergammaglobulinaemia was marked in 41 (74.5%) of 55 pts, elevated level of IgG was determined in 27 (49,15%) of 55 cases, IgM - in 18 (32,7%) and IgA - in 21 (38.2%). Interestingly, polyclonal IgE hypergammaglobulinaemia was detected in 12 (48,0%) of 25 cases of performed studies. Hypogammaglobulinaemia was detected in 8 (14,5%) of 55 cases. Oligoclonal gammapathy was determined in 4 (7.3%) of 55 pts. Monoclonal gammapathy was revealed in 11 (20,0%) of 55 cases. The amount of monoclonal immunoglobulin varied from 2.6 to 14.1 g/l. Monoclonal immunoglobulin Gk was detected in 5 of 11 pts, Gλ - in 2, Mλ - in 2, Mk - in 2. Monoclonal gammapathy was accompanied by polyclonal hypergammaglobulinaemia in 9 of 11 cases, hypogammaglobulinaemia - in 2., Conclusion: Quantitative and qualitative immunoglobulinopathies are observed in most patients at the onset of AITL. Quantitative abnormalities were determined more often than qualitative. Monoclonal gammapathy can be a manifestation of lymphoproliferation and other concomitant disorders. The prognostic value of immunochemical parameters is still unclear and requires dynamic observation and study.

Deficiency of adenosine deaminase 2 (DADA2) is a recently described autoinflammatory disorder. Genetic analysis is required to confirm the diagnosis. We aimed to describe the identifying symptoms and genotypes of patients referred to our reference centres and to improve the indications for genetic testing. DNA from 66 patients with clinically suspected DADA2 were sequenced by Sanger or next-generation sequencing. Detailed epidemiological, clinical and biological features were collected by use of a questionnaire and were compared between patients with and without genetic confirmation of DADA2. We identified 13 patients (19.6%) carrying recessively inherited mutations in ADA2 that were predicted to be deleterious. Eight patients were compound heterozygous for mutations. Seven mutations were novel (4 missense variants, 2 predicted to affect mRNA splicing and 1 frameshift). The mean age of the 13 patients with genetic confirmation was 12.7 years at disease onset and 20.8 years at diagnosis. Phenotypic manifestations included fever (85%), vasculitis (85%) and neurological disorders (54%). Features best associated with a confirmatory genotype included fever with neurologic or cutaneous attacks (odds ratio [OR] 10.71, p = 0.003 and OR 10.9, p < 0.001), fever alone (OR 8.1, p = 0.01), and elevated C-reactive protein (CRP) level with neurologic involvement (OR 6.63, p = 0.017). Our proposed decision tree may help improve obtaining genetic confirmation of DADA2 in the context of autoinflammatory symptoms. Prerequisites for quick and low-cost Sanger analysis include one typical cutaneous or neurological sign, one marker of inflammation (fever or elevated CRP level), and recurrent or chronic attacks in adults.

Competing Interests: Competing interests: None declared.

The etiology of primary antibody deficiencies is largely unknown. Beside rare monogenic forms, the majority of cases seem to have a more complex genetic basis. Whereas common variable immunodeficiency has been investigated in depth, there are only a few reports on milder primary antibody deficiencies such as idiopathic primary hypogammaglobulinemia and IgG subclass deficiency. We performed flow cytometric immunophenotyping in 33 patients with common variable immunodeficiency, 23 with idiopathic primary hypogammaglobulinemia and 21 with IgG subclass deficiency, as well as in 47 asymptomatic first-degree family members of patients and 101 unrelated healthy controls. All three groups of patients showed decreased memory B- and naïve T-cell subsets and decreased B-cell activating factor receptor expression. In contrast, circulating follicular helper T-cell frequency and expression of inducible T-cell co-stimulator and chemokine receptors were only significantly altered in patients with common variable immunodeficiency. Asymptomatic first-degree family members of patients demonstrated similar, albeit intermediate, alterations in naïve and memory B- and T-cell subsets. About 13% of asymptomatic relatives had an abnormal peripheral B-cell composition. Furthermore, asymptomatic relatives showed decreased levels of CD4 + recent thymic emigrants and increased central memory T cells. Serum IgG and IgM levels were also significantly lower in asymptomatic relatives than in healthy controls. We conclude that, in our cohort, the immunophenotypic landscape of primary antibody deficiencies comprises a spectrum, in which some alterations are shared between all primary antibody deficiencies whereas others are only associated with common variable immunodeficiency. Importantly, asymptomatic first-degree family members of patients were found to have an intermediate phenotype for peripheral B- and T-cell subsets., (Copyright© Ferrata Storti Foundation.)

Background: Randomized controlled trials and retrospective studies in ANCA-associated vasculitis (AAV) concurred that rituximab (RTX) is effective to induce and maintain remission. Infections and hypogammaglobulinemia during RTX were usually infrequent and uncomplicated. But in the Tromsø study cohort, 45% of patients with granulomatosis with polyangiitis (GPA) developed hypogammaglobulinemia during RTX maintenance leading to its discontinuation in 62%., Methods: To explain these differences in outcome when using RTX in AAV to maintain remission, we used statistical structural methods to compare the Tromsø study cohort with other published cohorts., Results: GPA patients' characteristics of the Tromsø study cohort were not so different compared with other cohorts. Rates of hypogammaglobulinemia and discontinuation of RTX seemed closely related to the cut-off used and to the levels of immunoglobulin (Ig) at baseline. Combination of low IgG serum levels at baseline (7.7 g/L) and low cut-off to define hypogammaglobulinemia in the Tromsø study cohort explained the high rate of hypogammaglobulinemia and discontinuation of RTX., Conclusions: Patients' characteristics in the Tromsø study cohort were not skewed, apart from IgG levels. Low IgG level at baseline seemed to contribute the most to hypogammaglobulinemia and its complications.

Background: Transplantation improves survival and the quality of life of patients with end-stage organ failure. Infection, due to surgical issues, host factors such as diabetes, immunosuppression, and hypogammaglobulinemia, is a major post-transplant complication. Clinical outcomes of prophylaxis or treatment of hypogammaglobulinemia in solid organ transplant recipients are not well established and are in need of further study., Methods/design: We will conduct a systematic review of studies investigating clinically relevant outcomes of immunoglobulin use either as prophylaxis or treatment of hypogammaglobulinemia after solid organ transplantation. Both randomized and non-randomized studies (excluding case reports and case series of less than 20 subjects) will be included. Outcomes of interest will include the overall rate of infection, hospital admission, hospital length of stay, intensive care unit admission, 1-year all-cause mortality, incidence of acute organ rejection, allograft survival within 1 year, and adverse events. We will search MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, Transplant library, and the International Clinical Trials Registry Platform for randomized and non-randomized studies on adult solid organ transplant patients who received prophylactic immunoglobulin or immunoglobulin treatment. Two reviewers will conduct all screening and data collection independently. We will assess study level of risk of bias using the Cochrane Risk of Bias Assessment Tool for randomized controlled trials and for non-randomized studies. If meta-analysis of outcome data is deemed appropriate, we will use random effects models to combine data for continuous and dichotomous measures., Discussion: The results of this systematic review may inform guideline development for measuring immunoglobulin level and use of immunoglobulin in solid organ transplant patients and highlight areas for further research., Systematic Review Registration: PROSPERO CRD42015017620.

Erythrocyte possesses high sphingosine kinase 1 (SphK1) activity and is the major cell type supplying plasma sphingosine-1-phosphate, a signaling lipid regulating multiple physiological and pathological functions. Recent studies revealed that erythrocyte SphK1 activity is upregulated in sickle cell disease (SCD) and contributes to sickling and disease progression. However, how erythrocyte SphK1 activity is regulated remains unknown. Here we report that adenosine induces SphK1 activity in human and mouse sickle and normal erythrocytes in vitro. Next, using 4 adenosine receptor-deficient mice and pharmacological approaches, we determined that the A2B adenosine receptor (ADORA2B) is essential for adenosine-induced SphK1 activity in human and mouse normal and sickle erythrocytes in vitro. Subsequently, we provide in vivo genetic evidence that adenosine deaminase (ADA) deficiency leads to excess plasma adenosine and elevated erythrocyte SphK1 activity. Lowering adenosine by ADA enzyme therapy or genetic deletion of ADORA2B significantly reduced excess adenosine-induced erythrocyte SphK1 activity in ADA-deficient mice. Finally, we revealed that protein kinase A-mediated extracellular signal-regulated kinase 1/2 activation functioning downstream of ADORA2B underlies adenosine-induced erythrocyte SphK1 activity. Overall, our findings reveal a novel signaling network regulating erythrocyte SphK1 and highlight innovative mechanisms regulating SphK1 activity in normal and SCD., (© 2015 by The American Society of Hematology.)

Background: A reduction of ADA2 activity due to autosomal recessive loss of function mutations in CECR1 results in a newly described vasculopathic phenotype reminiscent of polyarteritis nodosa, with manifestations ranging from fatal systemic vasculitis with multiple strokes in children to limited cutaneous disease in middle-aged individuals. Evidence indicates that ADA2 is essential for the endothelial integrity of small vessels. However, CECR1 is not expressed, nor is the ADA2 protein detectable, in cultured human endothelial cells, thus implicating additional cell types or circulating factors in disease pathogenesis., Methods: Considering the phenotypic overlap of ADA2 deficiency with the type I interferonopathy Aicardi-Goutières syndrome due to mutations in SAMHD1, we looked for the presence of an interferon signature in the peripheral blood of two newly ascertained ADA2-deficient patients., Results: We identified biallelic CECR1 mutations in two patients consistent with ADA2 deficiency. Both patients demonstrated an upregulation of interferon stimulated gene transcripts in peripheral blood. More strikingly however, genome-wide analysis revealed a marked overexpression of neutrophil-derived genes, suggesting that the vasculitis seen in ADA2 deficiency may be an indirect effect resulting from chronic and marked activity of neutrophils., Conclusions: We hypothesise that ADA2 may act as a regulator of neutrophil activation, and that a reduction of ADA2 activity results in significant endothelial damage via a neutrophil-driven process.

The neonatal receptor, FcRn, mediates both serum half-life extension as well as active transport of maternal IgG to the fetus during pregnancy. Therefore, transport efficiency and half-life go hand-in-hand. However, while the half-life of the human IgG2 subclass is comparable to IgG1, the placental transport of IgG2 is not, with the neonatal IgG1 levels generally exceeding maternal levels at birth, but not for IgG2. We hypothesized that the unique short-hinged structure of IgG2, which enables its κ-, but not λ-isotype to form at least three different structural isoforms, might be a contributing factor to these differences. To investigate whether there was any preference for either light chain, we measured placental transport of IgG subclasses as well as κ/λ-light chain isotypes of IgG1 and IgG2 in 27 matched mother-child pairs. We also studied the half-life of IgG1 and IgG2 light chain isotypes in mice, as well as that of synthesized IgG2 structural isotypes κA and κB. In order to investigate serum clearance of IgG1 and IgG2 light-chain isotypes in humans, we quantified the relative proportions of IgG1 and IgG2 light chains in hypogammaglobulinemia patients four weeks after IVIg infusion and compared to the original IVIg isotype composition. None of our results indicate any light chain preference in either of the FcRn mediated mechanisms; half-life extension or maternal transport.

Background: We aimed to determine the effects of treatment with intravenous immunoglobulin on bacterial infections in patients with hypogammaglobulinemia (HGG) after lung transplantation., Methods: We performed a randomized, double-blind, placebo-controlled two-period crossover trial of immune globulin intravenous (IVIG), 10% Purified (Gamunex, Bayer, Elkhart, IN) monthly in eleven adults who had undergone lung transplantation more than three months previously. We randomized study participants to three doses of IVIG (or 0.1% albumin solution (placebo)) given four weeks apart followed by a twelve week washout and then three doses of placebo (or IVIG). The primary outcome was the number of bacterial infections within each treatment period., Results: IVIG had no effect on the number of bacterial infections during the treatment period (3 during IVIG and 1 during placebo; odds ratio 3.5, 95% confidence interval 0.4 to 27.6, p = 0.24). There were no effects on other infections, use of antibiotics, or lung function. IVIG significantly increased trough IgG levels at all time points (least square means, 765.3 mg/dl during IVIG and 486.3 mg/dl during placebo, p<0.001). Four serious adverse events (resulting in hospitalization) occurred during the treatment periods (3 during active treatment and 1 during the placebo period, p = 0.37). Chills, flushing, and nausea occurred during one infusion of IVIG., Conclusions: Treatment with IVIG did not reduce the short-term risk of bacterial infection in patients with HGG after lung transplantation. The clinical efficacy of immunoglobulin supplementation in HGG related to lung transplantation over the long term or with recurrent infections is unknown., Trial Registration: Clinicaltrials.gov NCT00115778.

Background: Rituximab is a B cell depleting anti-CD20 monoclonal antibody. CD20 is not expressed on mature plasma cells and accordingly rituximab does not have immediate effects on immunoglobulin levels. However, after rituximab some patients develop hypogammaglobulinaemia., Methods: We performed a single centre retrospective review of 177 patients with multisystem autoimmune disease receiving rituximab between 2002 and 2010. The incidence, severity and complications of hypogammaglobulinaemia were investigated., Results: Median rituximab dose was 6 g (1-20.2) and total follow-up was 8012 patient-months. At first rituximab, the proportion of patients with IgG <6 g/L was 13% and remained stable at 17% at 24 months and 14% at 60 months. Following rituximab, 61/177 patients (34%) had IgG <6 g/L for at least three consecutive months, of whom 7/177 (4%) had IgG <3 g/L. Low immunoglobulin levels were associated with higher glucocorticoid doses during follow up and there was a trend for median IgG levels to fall after ≥ 6 g rituximab. 45/115 (39%) with IgG ≥ 6 g/L versus 26/62 (42%) with IgG <6 g/L experienced severe infections (p=0.750). 6/177 patients (3%) received intravenous immunoglobulin replacement therapy, all with IgG <5 g/L and recurrent infection., Conclusions: In multi-system autoimmune disease, prior cyclophosphamide exposure and glucocorticoid therapy but not cumulative rituximab dose was associated with an increased incidence of hypogammaglobulinaemia. Severe infections were common but were not associated with immunoglobulin levels. Repeat dose rituximab therapy appears safe with judicious monitoring.

Background: Hypogammaglobulinemia has been reported after cardiac surgery and may be associated with adverse outcomes. We sought to define baseline immunoglobulin (Ig) concentration in neonates and infants with congenital heart disease, determine their course after cardiopulmonary bypass (CPB), and determine if post-CPB hypogammaglobulinemia was associated with increased morbidity., Methods: This was a single-center, retrospective analysis of infants who underwent cardiac surgery with CPB between June 2010 and December 2011. The Ig concentration was obtained from banked plasma of 47 patients from a prior study (pre-CPB, immediately post-CPB, and 24 and 48 hours post-CPB). In addition, any Ig levels drawn for clinical purposes after CPB were included. Ig levels were excluded if drawn after chylothorax diagnosis or intravenous IgG administration., Results: The median age was 7 days. Preoperative Ig concentration was similar to that described in healthy children. IgG level decreased to less than 50% of preoperative concentration by 24-hour post-CPB and failed to recover by 7 days. Of 47 patients, 25 (53%) had low IgG (<248 mg/dL) after CPB. Despite no difference in demographics or risk factors between patients with low and normal IgG, low IgG patients had more positive fluid balance at 24 hours and increased proinflammatory plasma cytokine levels, duration of mechanical ventilation, and cardiac intensive care unit length of stay. In addition, low IgG patients had an increased incidence of postoperative infections (40% vs 14%; P = .056)., Conclusions: Hypogammaglobulinemia occurs in half of infants after CPB. Its association with fluid overload and increased inflammatory cytokines suggests it may result from capillary leak. Postoperative hypogammaglobulinemia is associated with increased morbidity, including more secondary infections., (Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

We present details of a man who was originally diagnosed with sarcoidosis, based on a combination of nodal granulomatous inflammation and radiology confirming bilateral hilar lymphadenopathy with pulmonary infiltrates. The patient subsequently developed splenomegaly and idiopathic thrombocytopenic purpura (ITP) and, latterly, a severe cavitating pneumonia. Serum immunoglobulins were checked, confirming panhypogammaglobulinaemia, and his diagnosis was revised to common variable immune deficiency (CVID). CVID is a heterogeneous condition, which can mimic sarcoidosis with granulomatous organ involvement and is commonly complicated by autoimmune disorders, including ITP. Prompt recognition is important to allow early introduction of immunoglobulin replacement therapy to decrease infection frequency, reduce development of secondary disease complications and retard progression of tissue damage. Given the potential for misdiagnosis and delay in recognition of CVID, serum immunoglobulin measurement should be a first-line investigation in patients with suspected sarcoidosis, even if the presentation is 'typical'. Current international sarcoidosis guidelines should be revised accordingly.

In this retrospective study we assessed the frequency of hypogammaglobulinemia in 708 patients with SIRS, severe sepsis and septic shock. We evaluated the relationship between hypogammaglobulinemia IgG, IgM and 28 day mortality. Total of 708 patients and 1,513 samples were analyzed. In the three subgroups we investigated, patients met the criteria of SIRS, severe sepsis and septic shock. IgG hypogammaglobulinemia was demonstrated in 114 patients with severe sepsis (25.2%), 11 septic shock patients (24.4%), and in 29 SIRS patients (13.9%). IgM hypogammaglobulinemia was documented in 55 patients with severe sepsis (12.2%), 6 septic shock patients (13.3%), and in 17 SIRS patients (8.1%). Mortality of patients with severe sepsis and normal IgG levels was significantly lower (111 patients; 32.8%) compared with those with IgG hypogammaglobulinemia (49 patients; 43.0%; p=0.001). Mortality of patients with septic shock and IgG hypogammaglobulinemia (n=5) was significantly higher compared with those with normal IgG levels (45.5% vs. 38.2%; p=0.001). Mortality of patients with severe sepsis and IgM hypogammaglobulinemia did not differ from that of patients with normal IgM levels (37.0 vs. 41.8%). Mortality of patients with septic shock and IgM hypogammaglobulinemia was significantly higher compared with those with normal IgM levels (50% vs. 38.5%; p=0.0001). This study documented relatively high incidence of hypogammaglobulinemia IgG and IgM in patients with severe sepsis, septic shock and SIRS respectively. The presence of IgG hypogammaglobulinemia in patients with severe sepsis is independent factor of mortality.

Common variable immunodeficiency disorders (CVID), the most frequent cause of symptomatic primary immunodeficiency, are defined by impaired antibody production. Notwithstanding, T cell activation and granulomatous manifestations represent the main causes of CVID morbidity even in patients receiving immunoglobulin (Ig) G replacement therapy. Additionally, gut pathology is a frequent feature of CVID. In this study, we investigated monocyte imbalances and their possible relationship with increased microbial translocation in CVID patients. Monocyte subsets were defined according to CD14 and CD16 expression levels and evaluated in terms of human leucocyte antigen D-related (HLA-DR), CD86 and programmed death-1 molecule ligand 1 (PD-L1) expression by flow cytometry, in parallel with the quantification of plasma lipopolysaccharide (LPS) and serum levels of soluble CD14 (sCD14), LPS-binding protein (LBP) and anti-LPS antibodies. CVID patients (n=31) featured significantly increased levels of serum sCD14 and an expansion of CD14(bright) CD16(+) monocytes in direct correlation with T cell and B cell activation, the latter illustrated by the frequency of the CD21(low) CD38(low) subset. Such alterations were not observed in patients lacking B cells due to congenital agammaglobulinaemia (n=4). Moreover, we found no significant increase in circulating LPS or LBP levels in CVID patients, together with a relative preservation of serum anti-LPS antibodies, in agreement with their presence in commercial IgG preparations. In conclusion, CVID was associated with monocyte imbalances that correlated directly with T cell activation markers and with B cell imbalances, without an association with plasma LPS levels. The heightened monocyte activated state observed in CVID may represent an important target for complementary therapeutic strategies., (© 2012 The Authors. Clinical and Experimental Immunology © 2012 British Society for Immunology.)

Patients undergoing allogeneic hematopoietic stem cell transplant (allo HCT) have a higher incidence of infections partly due to secondary hypogammaglobulinemia. We evaluated the role of IVIG in allo HCT patients who received prophylactic IVIG 200 mg/kg once weekly regardless of IgG level (Group 1, n = 115) compared with patients who received IVIG based on IgG level <400 mg/dL (Group 2, n = 114). Primary endpoints were the utilization of IVIG, incidence of veno-occlusive disease (VOD), graft-versus-host disease (GVHD), and documented infections within the first 100 days after allo HCT. Patients in both groups were similar except for a higher number of matched unrelated donor (MUD) transplants in Group 2 (62 vs. 41, P = 0.01). There were no significant differences in the incidence all grades of GVHD (55 vs. 50), VOD (2 vs. 0) or infections in the two groups except for a higher incidence of para-influenza infections in group 1 (9 vs. 0, P = 0.003) coinciding with the flu season. We recommend monthly monitoring of IgG level and replacement only if IgG level is <400 mg/dL., (Copyright © 2011 Wiley Periodicals, Inc.)

Background: Common variable immunodeficiency (CVID) is the most common form of symptomatic primary immunodeficiency disease. It is characterized by hypogammaglobulinemia, increased predisposition to infections, autoimmunity, and cancer., Objectives: This study was performed to evaluate the clinical and immunological features of a group of pediatric patients with CVID., Methods: The study population comprised 69 individuals with CVID diagnosed during childhood., Results: The patients were followed up for a mean (SD) period of 5.2 (4.3) years. The mean diagnostic delay was 4.4 (3.6) years, which was significantly lower in patients who were diagnosed recently. Children were classified according to 5 clinical phenotypes: infections only (n=39), polyclonal lymphocytic infiltration (n=17), autoimmunity (n=12), malignancy (n=7), and enteropathy (n=3). Postdiagnosis survival (10-year) was 71%., Conclusions: The high percentages of pediatric patients with CVID in Iran may be due to the considerable prevalence of parental consanguinity in the region and an underlying genetic background.

We herein present a case of Good syndrome complicated by diffuse pulmonary lesions similar to diffuse panbronchiolitis (DPB). A 45-year-old Japanese man was referred to our department due to recurrent lower respiratory tract infections that had started and ameliorated nine months after thymectomy for pure red cell aplasia and myasthenia gravis. Diffuse centrilobular opacities on chest computed tomography and positivity for HLA-B54 were consistent with DPB. Additionally, hypogammaglobulinemia and a marked decrease of B-lymphocytes were observed, and therefore Good syndrome was considered. Combination therapy with azithromycin and clarithromycin alleviated the patient's respiratory symptoms and reduced the exacerbation of chronic bronchitis.

Objective: Despite multiple treatment modalities, protein-losing enteropathy remains a serious complication to Fontan-type operations. Observations suggest inflammation to be involved in the pathogenesis of this condition, and immunomodulating treatment with high-dose intravenous immunoglobulin may modify the condition positively., Patients: Four patients with protein-losing enteropathy occurring after the total cavopulmonary connection, presenting with edema, hypoalbuminemia, and hypogammaglobulinemia, received intravenous immunoglobulin replacement therapy., Interventions: Standard replacement dose (1 g/kg) was used with intervals between infusions adjusted according to albumin and gamma globulin levels. Treatment periods ranged from 1 year to 5.3 years., Results: Intravenous immunoglobulin treatment was associated with significant increase in plasma albumin and to some extent in immunoglobulin G levels, as well as resolution of edema and the children started to thrive normally. During treatment, no serious infections or serious side effects were seen. Additional follow-up intervals ranged from 2 years to 2.8 years, during which only one episode of clinical relapse was registered and treated., Conclusions: We find the increase in albumin level and the resolution of protein-losing enteropathy symptoms after treatment with intravenous immunoglobulin of particular interest considering this serious complication to Fontan-type operations., (© 2011 Wiley Periodicals, Inc.)

Mutations in Bruton's tyrosine kinase (Btk) cause the B-cell disorder X-linked agammaglobulinaemia (XLA) in humans, but the effect of Btk deficiency in human bone health has not been investigated previously. In this study, we show that human Btk-deficient osteoclasts are defective at resorption activity in vitro owing to a dysregulation of the actin cytoskeletal function. Contrary to expectation, XLA patients did not exhibit increased bone density or alterations in serum markers of bone turnover, indicating that a potential compensation mechanism normalizes bone homeostasis. In contrast to the bone turnover markers, the levels of inflammatory cytokines interleukin 6 (IL-6), IL-1β, and tumor necrosis factor α (TNF-α) were significantly elevated in XLA patients' serum compared with control individuals. Supplementation of osteoclast cultures from normal and XLA subjects with serum from XLA patients or recombinant inflammatory cytokines IL-6, IL-1β, and TNF-α resulted in a stimulation of osteoclast activity in vitro, whereas the addition of cytokine-neutralizing antibodies inhibited this stimulatory effect, confirming that elevated inflammatory cytokines in XLA serum heightened osteoclast activity in vitro. This study provides novel evidence that Btk signaling is crucial for optimal actin cytoskeletal organization and lacunar resorption in isolated osteoclasts. In XLA patients, however, these inherent osteoclast defects are corrected by increased inflammatory cytokine levels, restoring osteoclast activity and leading to the normalization of bone density., (© 2011 American Society for Bone and Mineral Research.)

Transient hypogammaglobulinemia (THI) of infancy is a common primary immunodeficiency usually resolves by 3 years of age. In this study, clinical, immunological data and outcome of 101 retrospectively diagnosed THI patients were evaluated. Majority of them suffered from recurrent respiratory infections (70.3%). Initial IgG, IgM and IgA levels were 446.7±121.5, 67.5±32.8, and 25.6±16.8 mg/dl, respectively. Patients who had lower IgG levels on admission reached normal IgG levels earlier than others. Infants who were retarded to reach age-related normal levels for IgM and IgA were found to have higher CD3+CD8+ T cells on admission. During immunoglobulin abnormalities, mean lymphocyte subset percentages and absolute counts were normal. Mean percentage of CD19+CD27+ memory B cells was 3.4±1.4% which is not significantly different from healthy children. Most of the children had protective antibody responses to tetanus (87%) and Haemophilus influenzae type B (85.7%) vaccines. Patients with low anti-tetanus responses had higher initial natural killer (NK) cell percentages probably due to recurrent viral infections or relative dominance of innate responses. Follow-up of patients with initially high NK were found to have longer duration of deficiency hence these patients' recoveries were delayed. During follow-up, 91/101 (90.1%) children produced normali levels of IgG at the end of 29.2 ± 15.2 months. The results of this study indicate that some children will achieve normal levels of IgG within 30 months of age, and some will remain IgG subclass or IgA deficient. Determination of increased NK percentages in patients with non-protective vaccine response and normal percentages of memory B cells are noteworthy novel findings.