A case of hyperlysinemia identified by urine newborn screening.

Hyperlysinemia is a rare autosomal recessive deficiency of 2-aminoadipic semialdehyde synthase (AASS) affecting the initial step in lysine degradation. It is thought to be a benign biochemical abnormality, but reports on cases remain scarce. The description of additional cases, in particular, those identified without ascertainment bias, may help counseling of new cases in the future. It may also help to establish the risks associated with pharmacological inhibition of AASS, a potential therapeutic strategy that is under investigation for other inborn errors of lysine degradation. We describe the identification of a hyperlysinemia case identified in the Provincial Neonatal Urine Screening Program in Sherbrooke, Quebec. This case presented with a profile of cystinuria but with a very high increase in urinary lysine. A diagnosis of hyperlysinemia was confirmed through biochemical testing and the identification of biallelic variants in AASS. The p.R146W and p.T371I variants are novel and affect the folding of the lysine-2-oxoglutarate domain of AASS. The 11-month-old boy is currently doing well without any therapeutic interventions. The identification of this case through newborn urine screening further establishes that hyperlysinemia is a biochemical abnormality with limited clinical consequences and may not require any intervention.

Hepatic stellate cell-intrinsic role of SOCS1 in controlling hepatic fibrogenic response and the pro-inflammatory macrophage compartment during liver fibrosis.

Introduction: Hepatic stellate cells (HSC) become activated, differentiate to myofibroblasts and produce extracellular fibrillar matrix during liver fibrosis. The hepatic fibrogenic response is orchestrated by reciprocal interactions between HSCs and macrophages and their secreted products. SOCS1 can regulate several cytokines and growth factors implicated in liver fibrosis. Here we investigated the role of SOCS1 in regulating HSC activation. Methods: Mice lacking SOCS1 in HSCs (Socs1ΔHSC) were generated by crossing Socs1fl/fl and LratCre mice. Liver fibrosis was induced by carbon tetrachloride and evaluated by Sirius red staining, hydroxyproline content and immunostaining of myofibroblasts. Gene expression of pro-fibrogenic factors, cytokines, growth factors and chemokines were quantified by RT-qPCR. The phenotype and the numbers of intrahepatic leukocyte subsets were studied by flow cytometry. The impact of fibrosis on the development of diethyl nitrosamine-induced hepatocellular carcinoma was evaluated. Results: Socs1ΔHSC mice developed more severe liver fibrosis than control Socs1fl/fl mice that was characterized by increased collagen deposition and myofibroblast differentiation. Socs1ΔHSC mice showed a significant increase in the expression of smooth muscle actin, collagens, matrix metalloproteases, cytokines, growth factors and chemokines in the liver following fibrosis induction. The fibrotic livers of Socs1ΔHSC mice displayed heightened inflammatory cell infiltration with increased proportion and numbers of Ly6ChiCCR2+ pro-inflammatory macrophages. This macrophage population contained elevated numbers of CCR2+CX3CR1+ cells, suggesting impaired transition towards restorative macrophages. Fibrosis induction following exposure to diethyl nitrosamine resulted in more numerous and larger liver tumor nodules in Socs1ΔHSC mice than in Socs1fl/fl mice. Discussion: Our findings indicate that (i) SOCS1 expression in HSCs is a critical to control liver fibrosis and development of hepatocaellular carcinoma, and (ii) attenuation of HSC activation by SOCS1 regulates pro-inflammatory macrophage recruitment and differentiation during liver fibrosis.

Use of dexamethasone in acute rhabdomyolysis in LPIN1 deficiency.

Introduction: LPIN1 deficiency is an autosomal recessive form of early childhood recurrent severe rhabdomyolysis. Although not completely lucid yet, LPIN1 has been shown to modulate endosomal-related pro-inflammatory responses via peroxisome proliferator-activated receptor α (PPARα) and PPARγ coactivator 1α (PGC-1α). Treatment with anti-inflammatory agents such as dexamethasone has been proposed to improve the outcome. Case: We report a male toddler with recurrent episodes of complicated rhabdomyolysis, requiring prolonged intensive care unit admissions. Whole exome sequencing revealed a common homozygous 1.7 kb intragenic deletion in LPIN1. Despite optimal metabolic cares, the patient presented with an extremely high CK level where he benefited from intravenous dexamethasone (0.6 mg/Kg/day) for a period of 6 days. Results: Dexamethasone administration shortened the course of active rhabdomyolysis, intensive care admission and rehabilitation. It also prevented rhabdomyolysis-related complications such as kidney injury and compartment syndrome. Conclusion: Our patient showed a favorable response to parenteral dexamethasone, in addition to hyperhydration with IV fluids, sufficient calorie intake, and restricted dietary fat. The improvement with corticosteroids suggests an uncontrolled inflammatory response as the pathophysiology of LPIN1 deficiency.

SOCS1 Deficiency Promotes Hepatocellular Carcinoma via SOCS3-Dependent CDKN1A Induction and NRF2 Activation.

SOCS1 deficiency, which increases susceptibility to hepatocellular carcinoma (HCC), promotes CDKN1A expression in the liver. High CDKN1A expression correlates with disease severity in many cancers. Here, we demonstrate a crucial pathogenic role of CDKN1A in diethyl nitrosamine (DEN)-induced HCC in SOCS1-deficient mice. Mechanistic studies on DEN-induced genotoxic response revealed that SOCS1-deficient hepatocytes upregulate SOCS3 expression, SOCS3 promotes p53 activation, and Cdkn1a induction that were abolished by deleting either Socs3 or Tp53. Previous reports implicate CDKN1A in promoting oxidative stress response mediated by NRF2, which is required for DEN-induced hepatocarcinogenesis. We show increased induction of NRF2 and its target genes in SOCS1-deficient livers following DEN treatment that was abrogated by the deletion of either Cdkn1a or Socs3. Loss of SOCS3 in SOCS1-deficient mice reduced the growth of DEN-induced HCC without affecting tumor incidence. In the TCGA-LIHC dataset, the SOCS1-low/SOCS3-high subgroup displayed increased CDKN1A expression, enrichment of NRF2 transcriptional signature, faster disease progression, and poor prognosis. Overall, our findings show that SOCS1 deficiency in hepatocytes promotes compensatory SOCS3 expression, p53 activation, CDKN1A induction, and NRF2 activation, which can facilitate cellular adaptation to oxidative stress and promote neoplastic growth. Thus, the NRF2 pathway represents a potential therapeutic target in SOCS1-low/SOCS3-high HCC cases.

Pachyonychia Congenita Associated with a Novel Variant of KRT17 Presenting Unusual Oral Manifestations.

Pachyonychia congenita (PC) is a rare autosomal dominant condition caused by heterozygous mutation in one of five keratin genes. The purpose of this paper is to report a five-day-old infant with PC whose initial presentation revealed multiple malformed natal teeth and gingival lesions on the alveolar crest. Further investiga- tions led to genetic molecular testing of the child and his parents, which revealed a de novo and novel missense variant of KRT17 (c. 307C>T, p. Arg103Cys), resulting in a non-conservative amino-acid substitution and a diagnosis of PC. This case high- lights the need for multidisciplinary care and the relevance of molecular investigations for patients with multiple natal teeth. (J Dent Child 2019;86(1):61-3)
Received September 26, 2018; Last Revision November 19, 2018; Accepted November 19, 2018.

Proteomic investigations of human HERC2 mutants: Insights into the pathobiology of a neurodevelopmental disorder.

HERC2 is a giant protein with E3 ubiquitin ligase activity and other known and suspected functions. Mutations of HERC2 are implicated in the pathogenesis of various cancers and result in severe neurological conditions in Herc2-mutant mice. Recently, a pleotropic autosomal recessive HERC2-associated syndrome of intellectual disability, autism and variable neurological deficits was described; its pathogenetic basis is largely unknown. Using peripheral blood-derived lymphoblasts from 3 persons with homozygous HERC2 variants and 14 age- and gender-matched controls, we performed label-free unbiased HPLC-tandem mass spectrometry-based proteomic analyses to provide insights into HERC2-mediated pathobiology. We found that out of 3427 detected proteins, there were 812 differentially expressed proteins between HERC2-cases vs. controls. 184 canonical pathways were enriched after FDR adjustment, including mitochondrial function, energy metabolism, EIF2 signaling, immune functions, ubiquitination and DNA repair. Ingenuity Pathway Analysis® identified 209 upstream regulators that could drive the differential expression, prominent amongst which were neurodegeneration-associated proteins. Differentially expressed protein interaction networks highlighted themes of immune function/dysfunction, regulation of cell cycle/cell death, and energy metabolism. Overall, the analysis of the HERC2-associated proteome revealed striking differential protein expression between cases and controls. The large number of differentially expressed proteins likely reflects HERC2's multiple domains and numerous interacting proteins. Our canonical pathway and protein interaction network findings suggest derangements of multiple pathways in HERC2-associated disease.

Negative regulation of the hepatic fibrogenic response by suppressor of cytokine signaling 1.

Suppressor of cytokine signaling 1 (SOCS1) is an indispensable regulator of IFNγ signaling and has been implicated in the regulation of liver fibrosis. However, it is not known whether SOCS1 mediates its anti-fibrotic functions in the liver directly, or via modulating IFNγ, which has been implicated in attenuating hepatic fibrosis. Additionally, it is possible that SOCS1 controls liver fibrosis by regulating hepatic stellate cells (HSC), a key player in fibrogenic response. While the activation pathways of HSCs have been well characterized, the regulatory mechanisms are not yet clear. The goals of this study were to dissociate IFNγ-dependent and SOCS1-mediated regulation of hepatic fibrogenic response, and to elucidate the regulatory functions of SOCS1 in HSC activation. Liver fibrosis was induced in Socs1(-/-)Ifng(-/-) mice with dimethylnitrosamine or carbon tetrachloride. Ifng(-/-) and C57BL/6 mice served as controls. Following fibrogenic treatments, Socs1(-/-)Ifng(-/-) mice showed elevated serum ALT levels and increased liver fibrosis compared to Ifng(-/-) mice. The latter group showed higher ALT levels and fibrosis than C57BL/6 controls. The livers of SOCS1-deficient mice showed bridging fibrosis, which was associated with increased accumulation of myofibroblasts and abundant collagen deposition. SOCS1-deficient livers showed increased expression of genes coding for smooth muscle actin, collagen, and enzymes involved in remodeling the extracellular matrix, namely matrix metalloproteinases and tissue inhibitor of metalloproteinases. Primary HSCs from SOCS1-deficient mice showed increased proliferation in response to growth factors such as HGF, EGF and PDGF, and the fibrotic livers of SOCS1-deficient mice showed increased expression of the Pdgfb gene. Taken together, these data indicate that SOCS1 controls liver fibrosis independently of IFNγ and that part of this regulation may occur via regulating HSC proliferation and limiting growth factor availability.

Tumour-promoting role of SOCS1 in colorectal cancer cells.

The SOCS1 (Suppressor Of Cytokine Signalling 1) protein is considered a tumour suppressor. Notably, the SOCS1 gene is frequently silenced in cancer by hypermethylation of its promoter. Besides blocking inflammation, SOCS1 tumour suppressor activity involves Met receptor inhibition and enhancement of p53 tumour suppressor activity. However, the role of SOCS1 in colorectal cancer (CRC) remains understudied and controversial. Here, we investigated SOCS1 relevance for CRC by querying gene expression datasets of human CRC specimens from The Cancer Genome Atlas (TCGA), and by SOCS1 gain/loss-of-function analyses in murine and human colon carcinoma cells. Our results show that SOCS1 mRNA levels in tumours were more often elevated than reduced with respect to matched adjacent normal tissue of CRC specimens (n = 41). The analysis of TCGA dataset of 431 CRC patients revealed no correlation between SOCS1 expression and overall survival. Overexpression of SOCS1 in CRC cells triggered cell growth enhancement, anchorage-independent growth and resistance to death stimuli, whereas knockdown of SOCS1 reduced these oncogenic features. Moreover, SOCS1 overexpression in mouse CT26 cells increased tumourigenesis in vivo. Biochemical analyses showed that SOCS1 pro-oncogenic activity correlated with the down-modulation of STAT1 expression. Collectively, these results suggest that SOCS1 may work as an oncogene in CRC.

The extended clinical phenotype of 64 patients with dedicator of cytokinesis 8 deficiency.

BACKGROUND: Mutations in dedicator of cytokinesis 8 (DOCK8) cause a combined immunodeficiency (CID) also classified as autosomal recessive (AR) hyper-IgE syndrome (HIES). Recognizing patients with CID/HIES is of clinical importance because of the difference in prognosis and management. OBJECTIVES: We sought to define the clinical features that distinguish DOCK8 deficiency from other forms of HIES and CIDs, study the mutational spectrum of DOCK8 deficiency, and report on the frequency of specific clinical findings. METHODS: Eighty-two patients from 60 families with CID and the phenotype of AR-HIES with (64 patients) and without (18 patients) DOCK8 mutations were studied. Support vector machines were used to compare clinical data from 35 patients with DOCK8 deficiency with those from 10 patients with AR-HIES without a DOCK8 mutation and 64 patients with signal transducer and activator of transcription 3 (STAT3) mutations. RESULTS: DOCK8-deficient patients had median IgE levels of 5201 IU, high eosinophil levels of usually at least 800/µL (92% of patients), and low IgM levels (62%). About 20% of patients were lymphopenic, mainly because of low CD4(+) and CD8(+) T-cell counts. Fewer than half of the patients tested produced normal specific antibody responses to recall antigens. Bacterial (84%), viral (78%), and fungal (70%) infections were frequently observed. Skin abscesses (60%) and allergies (73%) were common clinical problems. In contrast to STAT3 deficiency, there were few pneumatoceles, bone fractures, and teething problems. Mortality was high (34%). A combination of 5 clinical features was helpful in distinguishing patients with DOCK8 mutations from those with STAT3 mutations. CONCLUSIONS: DOCK8 deficiency is likely in patients with severe viral infections, allergies, and/or low IgM levels who have a diagnosis of HIES plus hypereosinophilia and upper respiratory tract infections in the absence of parenchymal lung abnormalities, retained primary teeth, and minimal trauma fractures.

Regulation of MET receptor signaling by SOCS1 and its implications for hepatocellular carcinoma.

The SOCS1 gene is a frequent target of epigenetic repression in hepatocellular carcinoma. Many other types of cancer also harbor methylated SOCS1 gene. Besides, recent studies implicate microRNAs targeting SOCS1 in cancer progression. These findings suggest a broad tumor suppressor role of SOCS1 and have stimulated the quest to elucidate the underlying molecular mechanisms. The essential physiological function of SOCS1 is to attenuate interferon gamma signaling in immune cells. SOCS1 binds activated JAK kinases and the receptor chains of several cytokines, some of which are implicated in cancer progression. SOCS1 also facilitates ubiquitination and proteasomal degradation of many signaling molecules downstream of cytokine and growth factor receptors. We have shown that SOCS1 inhibits signaling via the hepatocyte growth factor receptor c-MET in hepatocytes. Aberrant MET signaling, implicated in the progression of many types of cancers, also contributes to the development of chemoresistance to tyrosine kinase inhibitors and drugs targeting other oncogenic signaling pathways. Here, we discuss the SOCS1-dependent regulation of MET signaling as an important mechanism underlying the tumor suppressor role of SOCS1 that is relevant not only to hepatocellular carcinoma but also to other types of cancers.

SOCS1 prevents potentially skin-reactive cytotoxic T lymphocytes from gaining the ability to cause inflammatory lesions.

Suppressor of cytokine signaling 1 (SOCS1) is a critical regulator of T lymphocyte homeostasis. SOCS1-deficient mice accumulate CD8(+) T cells, which display a memory-like phenotype and proliferate strongly to IL-15. Socs1(-/-) mice develop inflammatory skin lesions, however, the underlying mechanisms are not well understood. In order to investigate the role of SOCS1 in regulating CD8(+) T cells potentially reactive to tissue antigens (Ags) of the skin, we generated Socs1(-/-) mice expressing MHC-I-restricted Pmel-1 transgenic TCR specific to the melanoma-derived gp100 Ag, which is also expressed by normal melanocytes. Socs1(-/-) Pmel-1 cells express increased levels of memory markers CD44, Ly6C, CD122, and CD62L, and show downregulation of TCR and upregulation of CD5, suggesting in vivo TCR stimulation. However, stimulation of Socs1(-/-)Pmel-1 cells with gp100-derived peptide induced only marginal proliferation in vitro despite eliciting strong effector functions, which was associated with elevated Blimp-1 induction. Following adoptive transfer to Rag1(-/-) mice, Socs1(-/-)Pmel-1 cells underwent lymphopenia-induced proliferation and caused severe skin pathology characterized by inflammatory lesions in ears, muzzle, extremities, and eyes. These findings underscore the importance of SOCS1 in regulating potentially skin-reactive cytotoxic T lymphocytes, which could get activated under conditions that promote Ag-nonspecific, cytokine-driven proliferation.

Debilitating progressive encephalitis in a patient with BTK deficiency.

X-linked agammaglobulinemia (XLA), also known as Bruton's tyrosine kinase (BTK) deficiency, is a primary antibody deficiency, characterized by low number of B cells, agammaglobulinemia and increased susceptibility to a variety of infections. Herein, we report a case of XLA with confirmed BTK mutation that developed neurological deficits. While we could not detect any responsible microorganism in spite of comprehensive workup, brain magnetic resonance imaging revealed moderate brain atrophy. The diagnosis of progressive encephalitis was made for this patient. Patients with XLA have a higher chance of encephalitis compared with other primary antibody deficiencies. Given the violent nature of encephalitis, it is a concern among XLA patients.

SOCS1 controls liver regeneration by regulating HGF signaling in hepatocytes.

BACKGROUND & AIMS: Frequent repression of the Socs1 (suppressor of cytokine signaling 1) gene in hepatocellular carcinoma (HCC) and increased susceptibility of SOCS1-deficient mice to hepatocarcinogens suggest a tumor suppressor role for SOCS1 in the liver, but the underlying mechanisms remain unclear. Here we investigated the role of SOCS1 in regulating hepatocyte proliferation following partial hepatectomy and HGF stimulation. METHODS: Because Socs1(-/-) mice die prematurely due to deregulated IFNγ signaling, we used Socs1(-/-)Ifng(-/-) mice to study the role of SOCS1 in liver regeneration following partial hepatectomy. We examined the activation of signaling molecules downstream of IL-6 and hepatocyte growth factor (HGF) receptors in the regenerating liver, primary hepatocytes, and in human hepatoma cells. We examined the interaction between SOCS1 and the HGF receptor c-Met by reciprocal immunoprecipitation. RESULTS: Socs1(-/-)Ifng(-/-) mice displayed accelerated liver regeneration with increased DNA synthesis compared to Ifng(-/-) and wild type mice. The regenerating liver of Socs1(-/-)Ifng(-/-) mice did not show increased IL-6 signaling, but displayed earlier phosphorylation of Gab1, a signaling adaptor downstream of c-Met. Following HGF stimulation, hepatocytes from Socs1(-/-)Ifng(-/-) mice displayed increased phosphorylation of c-Met and Gab1, cell migration and proliferation. Accordingly, SOCS1 overexpression attenuated HGF-induced phosphorylation of c-Met, Gab1, and ERK1/2 in hepatoma cells, and decreased their proliferation and migration. SOCS1 interacted with the Tpr-Met, an oncogenic form of the Met receptor. CONCLUSIONS: SOCS1 attenuates c-Met signaling and thus negative regulation of HGF signaling could be an important mechanism underlying the anti-tumor role of SOCS1 in the liver.

Cutaneous granulomas in common variable immunodeficiency: case report and review of literature.

Common variable immunodeficiency (CVID) is a heterogeneous disease characterized by recurrent infections, autoimmunity, malignancies, and granulomatous inflammation. Granulomatous lesion is one of the important manifestations of CVID, which continues to be unknown to many clinicians. While noncaseating granulomatous lesions can be detected in lungs, liver, spleen or conjunctiva of CVID patients, there are only few reported cases with skin granuloma. This report presents a 27-year-old female with multiple persistent cutaneous granulomatous lesions on both hands. The patient had been well until age of 20 years, when she developed these skin lesions and frequent upper respiratory infections and bacterial pneumonia. Also, she experienced recurrent diarrhea (more than 10 episodes). Laboratory evaluation showed decreased serum levels of all immunoglobulin isotypes and low specific antibody responses. The diagnosis of CVID was based on clinical and laboratory findings. Intravenous immunoglobulin therapy at a dosage of 400-500 mg/kg monthly was introduced and improved skin lesions. In conclusion, taking history of recurrent infections and measuring immunoglobulin levels can be suggested in patients with granulomatous lesions instead of other expensive tests.

Mutations in STAT3 and diagnostic guidelines for hyper-IgE syndrome.

BACKGROUND: The hyper-IgE syndrome (HIES) is a primary immunodeficiency characterized by infections of the lung and skin, elevated serum IgE, and involvement of the soft and bony tissues. Recently, HIES has been associated with heterozygous dominant-negative mutations in the signal transducer and activator of transcription 3 (STAT3) and severe reductions of T(H)17 cells. OBJECTIVE: To determine whether there is a correlation between the genotype and the phenotype of patients with HIES and to establish diagnostic criteria to distinguish between STAT3 mutated and STAT3 wild-type patients. METHODS: We collected clinical data, determined T(H)17 cell numbers, and sequenced STAT3 in 100 patients with a strong clinical suspicion of HIES and serum IgE >1000 IU/mL. We explored diagnostic criteria by using a machine-learning approach to identify which features best predict a STAT3 mutation. RESULTS: In 64 patients, we identified 31 different STAT3 mutations, 18 of which were novel. These included mutations at splice sites and outside the previously implicated DNA-binding and Src homology 2 domains. A combination of 5 clinical features predicted STAT3 mutations with 85% accuracy. T(H)17 cells were profoundly reduced in patients harboring STAT3 mutations, whereas 10 of 13 patients without mutations had low (<1%) T(H)17 cells but were distinct by markedly reduced IFN-gamma-producing CD4(+)T cells. CONCLUSION: We propose the following diagnostic guidelines for STAT3-deficient HIES. Possible: IgE >1000IU/mL plus a weighted score of clinical features >30 based on recurrent pneumonia, newborn rash, pathologic bone fractures, characteristic face, and high palate. Probable: These characteristics plus lack of T(H)17 cells or a family history for definitive HIES. Definitive: These characteristics plus a dominant-negative heterozygous mutation in STAT3.

Large deletions and point mutations involving the dedicator of cytokinesis 8 (DOCK8) in the autosomal-recessive form of hyper-IgE syndrome.

BACKGROUND: The genetic etiologies of the hyper-IgE syndromes are diverse. Approximately 60% to 70% of patients with hyper-IgE syndrome have dominant mutations in STAT3, and a single patient was reported to have a homozygous TYK2 mutation. In the remaining patients with hyper-IgE syndrome, the genetic etiology has not yet been identified. OBJECTIVES: We aimed to identify a gene that is mutated or deleted in autosomal recessive hyper-IgE syndrome. METHODS: We performed genome-wide single nucleotide polymorphism analysis for 9 patients with autosomal-recessive hyper-IgE syndrome to locate copy number variations and homozygous haplotypes. Homozygosity mapping was performed with 12 patients from 7 additional families. The candidate gene was analyzed by genomic and cDNA sequencing to identify causative alleles in a total of 27 patients with autosomal-recessive hyper-IgE syndrome. RESULTS: Subtelomeric biallelic microdeletions were identified in 5 patients at the terminus of chromosome 9p. In all 5 patients, the deleted interval involved dedicator of cytokinesis 8 (DOCK8), encoding a protein implicated in the regulation of the actin cytoskeleton. Sequencing of patients without large deletions revealed 16 patients from 9 unrelated families with distinct homozygous mutations in DOCK8 causing premature termination, frameshift, splice site disruption, and single exon deletions and microdeletions. DOCK8 deficiency was associated with impaired activation of CD4+ and CD8+T cells. CONCLUSION: Autosomal-recessive mutations in DOCK8 are responsible for many, although not all, cases of autosomal-recessive hyper-IgE syndrome. DOCK8 disruption is associated with a phenotype of severe cellular immunodeficiency characterized by susceptibility to viral infections, atopic eczema, defective T-cell activation and T(h)17 cell differentiation, and impaired eosinophil homeostasis and dysregulation of IgE.

IgA deficiency: correlation between clinical and immunological phenotypes.

BACKGROUND: IgA deficiency (IGAD) is the most common primary antibody deficiency. Although many affected individuals have no apparent symptom, selected patients suffer from recurrent mucosal infections, allergies, and autoimmune diseases. We aimed to investigate the clinical features in relation to immune function of Iranian patients with symptomatic IGAD. METHODS: Thirty-seven patients (21 male and 16 female), aged 4-32 years, were evaluated in this study. Patients were followed for a total of 131 patient years with a mean follow-up of 3.5 years per patient. RESULTS: The most prevalent presentations were recurrent infections occurring in 27 subjects, followed by allergy in eight cases and autoimmunity in two patients. However, during the follow-up period, 35 patients developed infections in respiratory and gastrointestinal tracts, necessitating medical care. Apart from infections, allergy was the most frequent complaint (31 cases); the major features were asthma, atopic dermatitis, and allergic rhinoconjunctivitis. Autoimmune diseases were documented in ten cases; thyroiditis was the most common. In 31 patients who received unconjugated pneumococcal polyvalent vaccine, antibody response against polysaccharide antigen was measured before and 28 days after vaccination. One fourth of vaccinated patients were hyporesponsive to vaccine; four of these patients developed bronchiectasis. The patients with IGAD were classified into two groups: group 1 (14 cases) consisted of patients with IGAD and other associated immune defects, such as immunoglobulin G (IgG) subclass deficiency and defective specific antibody production. Group 2 (23 cases) had isolated IGAD without other immunological abnormalities. There was a significantly increased number of lower respiratory tract infections in group 1 compared with group 2 (P = 0.006). Moreover, four patients of group 1 had bronchiectasis whereas none of the patients in group 2 developed this complication (P = 0.015). CONCLUSION: Subclassification of IGAD regarding the existence of associated immune defects is useful in terms of morbidity and planning for medical care. IgA-deficient patients with concomitant immune defects such as defects in specific antibody production have higher rates of recurrent infections and bronchiectasis, which necessitates more effective monitoring.

Presence of Idiopathic Thrombocytopenic Purpura and autoimmune hemolytic anemia in the patients with common variable immunodeficiency.

Common Variable Immunodeficiency (CVID) is a heterogeneous group of disorders characterized by hypogammaglobulinemia and an increased susceptibility to recurrent infections as well as autoimmunity and malignancies. Idiopathic Thrombocytopenic Purpura (ITP) and Autoimmune Hemolytic Anemia (AIHA) are two autoimmune disorders which may be seen in association with CVID. Among 85 CVID patients, seven cases had ITP and/or AIHA (8%). Four of these patients had one or more episodes of ITP, one patient had AIHA, and two patients had both ITP and AIHA (Evans syndrome). Almost, all patients experienced chronic and recurrent infections mostly in respiratory and gastrointestinal systems during the course of the disease. Among the seven patients, five presented their underlying disease with recurrent respiratory and/or gastrointestinal tract infections, while in two remaining patients, CVID was presented with ITP. Three patients died until now; two because of hepatic failure and one due to pulmonary hemorrhage. As CVID is prone to autoimmune disorders, it should be considered as a differential diagnosis of adult-onset ITP and possibly in children. Chronic and recurrent ITP, especially in the presence of propensity to respiratory and gastrointestinal infections mandate the evaluation for an underlying immune dysregulation such as CVID.

Genotype-phenotype correlation in Bruton's tyrosine kinase deficiency.

Bruton's tyrosine kinase (Btk) belongs to the Tec family of nonreceptor protein tyrosine kinases. Mutations in the BTK gene cause X-linked agammaglobulinemia (XLA); a primary immunodeficiency disorder in human. No clear genotype-phenotype correlation has been established in XLA so far. To determine how differently mutations in BTK affect the severity of the disease and if BTK promoter polymorphic variant or intron 1 polymorphic variant in Tec, a cytoplasmic tyrosine kinase that might substitute for Btk, could contribute to the clinical phenotype, we analyzed the clinical and molecular findings in a cohort of XLA patients. Polymorphisms in BTK promoter and TEC intron 1 regions include substitutions of C>T (rs2071219) and T>C (rs2664019), respectively. Btk expression was evaluated by means of western immunoblotting and fluorescence-activated cell sorter analysis. Mutations were categorized as mild or severe and patients were evaluated for the clinical severity of disease. On the basis of the results, severe genotypes do not necessarily lead to severe phenotypes. More over, in a considerable number of patients with mild phenotype we showed a severe mutation with a tendency toward C substitution in the polymorphic site on TEC intron 1.