Clinical, immunological and molecular characteristics of 37 Iranian patients with X-linked agammaglobulinemia

BACKGROUND: X-linked agammaglobulinemia (XLA) is a hereditary immunodeficiency characterized by an early onset of recurrent bacterial infections, a profound deficiency of all immunoglobulin isotypes and a markedly reduced number of peripheral B lymphocytes. Eighty-five percent of the patients with this phenotype have mutations in Bruton's tyrosine kinase (BTK) gene. METHODS: To provide an informative outlook of clinical and immunological manifestations of XLA in Iran, 37 Iranian male patients with an age range of 1-34 years, followed over a period of 25 years, were studied. Twenty-four of the 37 patients were screened for BTK gene mutation using PCR-SSCP followed by direct sequencing. BTK protein expression assay was done by flow cytometry in 9 families. RESULTS: All patients first presented with infectious diseases, the most common of which were respiratory tract infections. Eighteen different mutations were identified, 13 of which were novel: IVS1+5G>C, 1896G>A, 349delA, 1618C>T, 1783T>C, 2084A>G, 1346delT, 1351delGAG, 587A>G, IVS14-1G>A, IVS3+2T>C, 1482G>A, 1975C>A. CONCLUSION: The fact that we found a great number of novel mutations in a relatively limited number of patients underlines the heterogeneity of BTK mutations in the Iranian population. The large number of new mutations indicates that extended studies in this region would be rewarding.     

Clinical,immunological and genetic characterization of patients with X-linked agammaglobulinemia in Costa Rica

X-linked agammaglobulinemia is caused by mutations in the gene encoding Bruton tyrosine kinase. It produces an arrest in the maturation and differentiation of B cells with very low levels of all immunoglobulins isotypes. The aim of the study was to characterize the clinical, immunological and genetic defects in patients with XLA in Costa Rica. Sixteen cases were identified over a period of 30 years, a case every 2 years, approximately. Three patients were asymptomatic and diagnosis was made on family history. The average age of onset of symptoms was 1.46 years-old (0.08–6.1). Six patients (44%) had onset of symptoms before 1 year of age and 12 (81%) patients before 5 years of age. The average age of diagnosis was 3.63 years-old (0.17–13, SD 3.51 years-old the average time between the onset of symptoms and the diagnosis was 2.5 years (2.5 months to 12 years, SD 3 years). The initial reason to study the patients was a recurrent infection, family history of XLA, arthritis and neutropenia. Four patients had pneumonia and two had suppurative lung disease. Nine patients had recurrent infections: acute otitis media, sinusitis, mastoiditis and recurrent diarrhoea. Three patients presented with arthritis. Neutropenia as an isolated event was not identified in any case. All patients receive monthly IVIG and no deaths were reported. Three new likely pathogenic/pathogenic variants in BTK gene have been described in our population. This is the first report of XLA Costa Rican patients and their BTK mutations.     

Clinical,immunological and genomic characteristics of children with X-linked agammaglobulinemia from Kerala,South India

X-linked agammaglobulinemia (XLA) is an X-linked recessive primary immunodeficiency disorder caused due to a pathogenic variant in the Bruton tyrosine (BTK) gene with an incidence of 1:379,000 live births and 1:190,000 male births. Patients affected with XLA present with recurrent infections of the gastrointestinal and respiratory tracts. Here we report the first case series of 17 XLA patients of 10 South Indian families with a wide spectrum of clinical and genetic features. In our cohort, patients presented mainly with recurrent pneumonia, gastrointestinal infection, otitis media, pyoderma, abscesses, empyema, arthritis, and osteomyelitis. Using next-generation and Sanger sequencing we have identified 10 unique pathogenic and likely pathogenic variants in 17 patients. This encompasses three nonsynonymous, two stop-gain, two frameshifts, two structural, and one splicing variant, out of which two of them are novel. Based on the type of variant, patients had variable clinical features and treatment responses. We have also evaluated Btk protein expression for six patients in comparison to the healthy individuals and determined mosaic Btk expression patterns in four mothers. We have also performed family screening in 6 families using Sanger sequencing and identified 19 carriers for the variant. The diagnosis for the patients led to the proper treatment i.e. 15 patients were on intravenous immunoglobulin (IVIG) and the other two had successful hematopoietic stem cell transplantation (HSCT). Unfortunately, two of our patients died due to sepsis, while on IVIG. We envision the present study could help in better understanding of patients with XLA and help in family screening and prenatal diagnosis. To the best of our knowledge, this is the largest case series of patients affected with XLA from South India.     

Carrier detection in X-linked agammaglobulinemia by analysis of X-chromosome inactivation

We used a recently developed strategy to analyze patterns of X-chromosome inactivation in human cell populations in order to study female members of families with X-linked agammaglobulinemia--i.e., to detect the carrier state and to test the hypothesis that the disorder results from a defect intrinsic in the development of B cells. According to this strategy, recombinant-DNA probes simultaneously detect restriction-fragment-length polymorphisms and patterns of methylation of X-chromosome genes. Random X-inactivation patterns were observed in isolated peripheral-blood granulocytes, T lymphocytes, and B lymphocytes of women who were not carriers. In contrast, one of the two X chromosomes was preferentially active in the peripheral B cells, but not the T cells or granulocytes, of three carriers of the disorder. This observation strongly supports the hypothesis that X-linked agammaglobulinemia results from an intrinsic defect in B-cell development. Moreover, the analysis described here can be used for direct identification of carriers in families with this disease.     

Clinical characteristics and molecular analysis of 21 Chinese children with congenital agammaglobulinemia

Congenital agammaglobulinemia is a humoral primary immunodeficiency and affected patients have extremely low levels of peripheral B cells and profound deficiency of all immunoglobulin isotypes. Mutations of the Bruton's tyrosine kinase (BTK) gene are responsible for most of the congenital agammaglobulinemia. In this study, the phenotypes of congenital agammaglobulinemia were investigated in 21 male children from 21 unrelated Chinese families. Sixteen different mutations of BTK gene were identified in 18 patients, and three patients did not have BTK gene mutations. Nine mutations had been reported previously including one gross deletion (c.722_2041del), one missense mutation (c.1764G>T), three non-sense mutations (c.194C>A, c.895C>T and c.1821G>A) and four invariant splice-site mutations (c.971+2T>C, c.1481+2T>A, c.1482-2A>G, c.1699-2A>G). Seven novel mutations were identified (c.373_441del, c. 504delG, c.537delC, c.851delA, c.1637G>A, c.1879T>C and c. 1482_1882 del). Ten of the eighteen mutations of BTK gene were located in the TK domain, four in the PH domain, three in the SH3 domain and one spanned the TH, SH3, SH2 and TK domain. Candidate genes of autosomal-recessive agammaglobulinemia, including IGHM, CD79a, CD79b and IGLL1, were screened in three patients without mutations in the BTK gene. A compound heterozygosity mutation in the IGHM gene (c.1956G>A, c.175_176insC) was identified in one patient. The results of our study further support that molecular genetic testing represents an important tool for early confirmed diagnosis of congenital agammaglobulinemia and may allow accurate carrier detection and prenatal diagnosis.     

一个X-连锁肾上腺脑白质营养不良家系的临床特点及基因变异分析

目的:探讨一个X-连锁肾上腺脑白质营养不良家系的临床特点及 ABCD1基因的变异方式。 方法:分析X-连锁肾上腺脑白质营养不良家系的临床资料,采用PCR方法对家系中的先证者、父母以及100名健康对照者的 ABCD1基因进行DNA测序。 结果:患者主要以脑干、小脑损害为突出表现...     

Comparative analysis of flow cytometric techniques in assessment of ZAP-70 expression in relation to IgVH mutational status in chronic lymphocytic leukemia

We compared 1 subjective and 5 objective flow cytometric methods to evaluate zeta-associated protein (ZAP-70) expression in relation to immunoglobulin heavy-chain variable-region (IgVH) gene mutational status in 154 samples from 125 patients with chronic lymphocytic leukemia (CLL). ZAP-70 expression determined by all methods used correlated with IgVH gene mutational status, but none of them demonstrated high concordance rates. Of the objective methods, ZAP-70 staining determined as a ratio of molecules of equivalent soluble fluorochrome intensity in CLL cells to that in normal B cells (ZAP-70+ staining in IgVH germline cases, 59%; ZAP-70- in IgVH mutated cases, 75%) or T cells (ZAP-70+ in IgVH germline cases, 66%; ZAP-70- in IgVH mutated cases, 57%) provides the best combination for assigning ZAP-70+ status to IgVH germline and ZAP-70- status to IgVH mutated cases. The subjective method based on ZAP-70 expression in natural killer/T cells gave a similar result, but reproducibility between laboratories may be difficult. Further studies on ZAP-70 expression in relation to clinical parameters may address whether ZAP-70 is an independent prognostic marker for CLL.     

Clinical,immunological, and molecular analysis in a large cohort of patients with X-linked agammaglobulinemia: an Italian multicenter study

A questionnaire-based retrospective clinical and immunological survey was conducted in 73 males with a definite diagnosis of X-linked agammaglobulinemia based on BTK sequence analysis. Forty-four were sporadic and 29 familial cases. At December 2000, the patients' ages ranged from 2 to 33 years; mean age at diagnosis and mean duration of follow-up were 3.5 and 10 years respectively. After the mid-1980s all but 2 were on intravenous immunoglobulin (IVIG) substitution therapy, with residual IgG >500 mg/dl in 94% of the patients at the time of enrollment. Respiratory infections were the most frequent manifestation both prior to diagnosis and over follow-up. Chronic lung disease (CLD) was present in 24 patients, in 15 already at diagnosis and in 9 more by 2000. The cumulative risk to present at diagnosis with CLD increased from 0.17 to 0.40 and 0.78 when the diagnosis was made at the ages of 5, 10, and 15 years respectively. For the 9 patients who developed CLD during follow-up, the duration of follow-up, rather than age at diagnosis; previous administration of intramuscular immunoglobulin; and residual IgG levels had a significant effect on the development of CLD. Chronic sinusitis was present in 35 patients (48%), in 15 already at diagnosis and in 20 by 2000. Sistemic infections such as sepsis and meningitis/meningoencephalitis decreased over follow-up, probably due to optimal protection provided by high circulating IgG levels reached with IVIG.     

Glioblastomatous transformation of ganglioglioma: case report with reference to molecular genetic and flow cytometric analysis

Gangliogliomas generally behave as benign indolent tumors. However, gangliogliomas undergoing malignant transformation have also been reported. The molecular basis for the malignant transformation of gangliogliomas remains unclear. We describe a case of ganglioglioma, which had transformed to glioblastoma after the gross total resection of the original tumor, in a 4-year-old girl. The present case is unusual in four aspects: (i) it arose from a low-grade ganglioglioma in the absence of previous radiation or chemotherapy, which is the fourth reported case; (ii) the original tumor showed a high proliferative index on flow cytometry but a low Ki-67 labeling index, implying that the application of flow cytometry might play a certain role in predicting biological and clinical behavior of low grade gangliogliomas; (iii) p53 mutation and deletion appeared in the secondary glioblastoma, which was not shown in the original well-differentiated ganglioglioma; and (iv) the transformed glioblastoma showed p16 inactivation detected by methylation and deletion, which are relatively uncommon genetic events in secondary glioblastomas. This is the first report of a genetic alteration in glioblastoma arising from a well differentiated ganglioglioma prior to radiation or chemotherapy. Based on the above findings, irrespective of radiotherapy or chemotherapy, rare recurrence of malignant evolution, especially tumors of high S-phase fraction on flow cytometry, warrants long-term follow-up, even in a well-differentiated ganglioglioma.     

The health status and quality of life of adults with X-linked agammaglobulinemia

Forty-one adults (mean age 33) with a definitive diagnosis of X-linked agammaglobulinemia (XLA) completed a questionnaire concerning current and past medical problems and quality of life. Thirty-six of the 41 were working full time or were full time students; 18 had not missed any work or school due to infection in the previous year. Their quality of life was equivalent to that of the general US male population. Thirteen of the 41 reported that they had chronic lung disease, and 33 indicated that they had one or more episodes of sinusitis in the preceding year. Arthritis, diarrhea and skin infections were common but not debilitating. The 41 study subjects were more likely to have a prior family history of XLA, and they were more likely to have milder mutations in Btk, the gene responsible for XLA. These results indicate that most adults with XLA are moderately healthy and lead productive lives.     

The accuracy of combined cytopathologic and flow cytometric analysis of fine-needle aspirates of lymph nodes

We studied flow cytometry in 156 fine-needle aspirations (FNAs) of lymph nodes performed between June 1993 and September 1998. Information from flow cytometry was combined with cytomorphologic evaluation, and the diagnosis determined by using combined modalities was compared with tissue biopsy results or clinical follow-up. In 74 cases, a combined cytopathologic-flow cytometric diagnosis of lymphoma was made; histologic material was available for 52 patients; in no case was a benign process found. The lymphoma grade assigned agreed with histopathologic findings in 45 of 48 cases with a specific cytologic diagnosis. Treatment was initiated on the basis of the FNA alone for 17 of 52 patients with a history of lymphoma and in 22 additional patients with no follow-up biopsy. Among 71 cases in which the diagnosis using both modalities was benign, the only false-negative was 1 case of Hodgkin disease. Of the 156 cases, 11 were considered atypical or suggestive of lymphoma; biopsies from 8 of 10 patients revealed lymphoma. A combination of flow cytometry and cytomorphology of cells obtained by FNA of lymph nodes can distinguish between benign and malignant lymphoid infiltrates and support a diagnosis of lymphoma that permits definitive therapy in most cases.     

Clinical characteristics and genetic analysis in women with premature ovarian insufficiency

ObjectivePremature ovarian insufficiency (POI) is defined as a primary ovarian defect characterized by absent menarche (primary amenorrhea) or premature depletion of ovarian follicles before the age of 40 (secondary amenorrhea) with hypergonadotropism and hypoestrogenism.MethodsWe studied the clinical, biological, and genetic data related to 50 POI patients with a mean age of menopause of 29 years (94% with secondary amenorrhea, 6% with primary amenorrhea and 15% with a family history of POI). Seventeen patients were affected by endocrine autoimmune diseases, antral follicles were observed in 31 patients by ultrasonography.ResultsKaryotype analysis did not show any abnormality of the X chromosome. No mutation in FSH receptor and GDF-9 genes was reported, while in one patient a variant of BMP-15 gene (A180T) was found. Four patients had fragile X mental retardation 1 gene (FMR1) premutation and one an intermediate sized CGG repeats of the same gene. Two patients with FMR1 premutation were sister and developed secondary amenorrhea at the age of 34 and 37 years. The other two patients presented with oligoamenorrhea at the age of 39 and 34 years. The patient harboured the intermediate sized CGG repeats developed secondary amenorrhea at the age of 33 years.ConclusionsThe genetic analysis performed on a cohort of patients with POI revealed that 8% had FMR1 premutation and only one patient a previously known variant of BMP-15 gene. No alteration of the karyotype and FSH receptor and GDF-9 genes was evidenced.     

Evaluation of stimulus-induced acrosome reaction by two-colour flow cytometric analysis

Acrosome status in human spermatozoa from 20 normozoospermic men was evaluated by flow cytometry following the induction of the acrosome reaction with the ionophore A23187. Dual fluorescence staining of methanol fixed spermatozoa incubated with and without (control) the ionophore A23187 was performed with probes which targeted the outer acrosomal membrane (OAM) (rhodamine-labelled Arachis hypogaea agglutinin) or constituents of the acrosomal vesicle (fluorescein- labelled Pisum sativum agglutinin). Flow cytometry analysis revealed two major subpopulations of cells: acrosome-intact and acrosome-reacted spermatozoa after induction of the acrosome reaction. The intensity of green and red fluorescence in acrosome-reacted spermatozoa was significantly lower than that of the acrosome-intact control spermatozoa (P < 0.0001). The intensity of green fluorescence in the acrosome-intact subpopulation of spermatozoa was significantly higher than that of the control population (P < 0.002). Exposure of spermatozoa to the ionophore A23187 resulted in reliable enhancement of the number of spermatozoa with very high intensity of green and/or red fluorescence compared with the control (P < 0.03). An inverse correlation between the number of acrosome-reacted spermatozoa and spermatozoa with a very high intensity of green and/or red fluorescence was demonstrated (r = -0.631, P < 0.01). This method provides an objective and efficient procedure for quantitative estimation of the acrosomal status of human spermatozoa.      

Clinical significance of thiazide-sensitive Na-Cl cotransporter gene by mutational analysis

Thiazide-sensitive Na-Cl cotransporter (TSC, SLC12A3) is located on chromosome 16q13 and is expressed specifically in the renal distal convoluted tubule, where it mediates the reabsorption of Na+ and Cl-. Mutation of TSC is known to be responsible for Gitelman's syndrome, an autosomal recessive renal tubular disorder characterized by low blood pressure due to renal sodium wasting, hypokalemia, metabolic alkalosis, hypomagnesemia and normocalcemic hypocaliuria. We assessed mutational analysis of the TSC gene in 35 patients with Gitelman's syndrome. We found 16 missense mutaions, insertion of 18bp in the 6th exon, deletion of C in the 9th exon and deletion of C in the 16th exon. These results suggest that there is no mutational hot spot in the TSC gene. These 19 mutations include eight novel mutations: R261C, N406H, A523T, M672I, R1009Q, N1014K, deletion of C in the 9th exon and deletion of C in the 16th exon. The eight novel mutations might be responsible for impairment of NaCl reabsorption leading to the principal clinical features of Gitelman's syndrome in these patients. These mutations could bring new insights into genotype-phenotype correlations among the hypokalemic tubulopathies. Recently, genome-wide association studies, using SNPs to identify loci involved in susceptibility to common diseases, showed that the TSC gene may contribute to genetic susceptibility to diabetic nephropathy in Japanese. In addition, substitution of Arg904 to Gln in the TSC gene has been reported to predispose essential hypertension in Swedish and Japanese populations. Further studies are needed to clarify the possible associations of the TSC gene with common diseases.     

Delayed diagnosis in X-linked agammaglobulinemia and its relationship to the occurrence of mutations in BTK non-kinase domains

Background: X-linked agammaglobulinemia (XLA) is characterized by the absence of immunoglobulin and B cells. Patients suffer from recurrent bacterial infections from early childhood, and require lifelong immunoglobulin replacement therapy. Mutations in BTK (Bruton’s Tyrosine Kinase) are associated with this phenotype. Some patients that present XLA do not show typical clinical symptoms, resulting in delayed diagnosis due to the lack of a severe phenotype. This study presents a report of five XLA patients from four different families and attempts to determine a relationship between delayed diagnosis and the occurrence of BTK mutations.

Methods: Samples from patients with antibody deficiency were analyzed to determine BTK expression, immunophenotyping and mutation analysis. Clinical and laboratory data was analyzed and presented for each patient.

Results: Most patients presented here showed atypical clinical and laboratory data for XLA, including normal IgM, IgG, or IgA levels. Most patients expressed detectable BTK protein. Sequencing of BTK showed that these patients harbored missense mutations in the pleckstrin homology and Src-homology-2 domains. When it was compared to public databases, BTK sequencing exhibited a new change, along with three other previously reported changes.

Conclusions: Delayed diagnosis and atypical manifestations in XLA might be related to mutation type and BTK expression.     

Lymphocyte analysis in a patient with X-linked agammaglobulinemia and isolated growth hormone deficiency after development of echovirus dermatomyositis and meningoencephalitis

A previously described patient with X-linked agammaglobulinemia and growth hormone deficiency developed an echovirus-associated meningoencephalitis and dermatomyositis-like syndrome while being treated with intramuscular gamma globulin and human growth hormone. Initiation of high-dose intravenous gamma globulin resulted in resolution of the clinical symptoms and the patient has remained asymptomatic over the past 55 months. Lymphocyte phenotype analysis at the time of presentation with echovirus infection revealed an increase in CD2+, CD16+, HNK-1+ lymphocytes, a decrease in CD4+ T cells as well as absence of B cells. This elevation in the LGL/NK phenotype resolved with clinical improvement. In addition, there was evidence of lymphocyte activation following the development of echovirus infection (increase in HLA-DR expression and elevated serum IL-2 receptor levels) which resolved with clinical improvement. A muscle biopsy obtained during the period of the dermatomyositis-like syndrome demonstrated a CD8+ lymphocytic infiltrate very similar to the observations in classical dermatomyositis. Taken together, these findings suggest that growth hormone therapy in this patient failed to alter the humoral immunodeficiency. In addition, serum IL-2 receptor levels and lymphocyte phenotyping may be useful adjuncts for monitoring echovirus disease in immunodeficient patients.     

中国X连锁无丙种球蛋白血症40例基因型表型相关性分析

目的通过中国X连锁无丙种球蛋白血症（XLA）患儿临床表现、免疫功能评价、Bruton＇s酪氨酸激酶（BTK）的表达及BTK基因突变分析,分析基因型和表型间可能存在的关系。方法选取拟诊为XLA患儿,使用抗BTK单克隆抗体通过流式细胞技术分析单核细胞BTK蛋白表达。采用RT-PCR获得患儿cDNA,使用8对不同引物分2步扩增BTKcDNA,PCR产物测序。突变结果通过对DNA外显子相应部位扩增、测序证实。并对确诊XLA患儿的母亲及家族中部分亲属进行BTK蛋白表达和BTK基因分析。结果①40/50例原发性低丙种球蛋白血症患儿经BTK基因突变分析确诊为XLA,以错义突变（16例,40.0%）和无义突变（13例,32.5%）为主。②突变类型为错义突变的患儿平均起病年龄为（1.4±1.1）岁,其他突变类型患儿为（1.4±0.7）岁,差异无统计学意义（P=0.45）。错义突变的发生率随年龄的增长呈上升趋势,无义突变的发生率呈下降趋势。③34/40例（85.0%）B细胞〈0.1%;4例（10.0%）B细胞在1%～2%,其中错义突变2例,无义突变1例,剪接突变1例;2例（5.0%）B细胞为2%,均为错义突变。④血清IgG〈3g·L-1患儿BTK基因突变类型以错义突变和无义突变为主。⑤错义突变患儿BTK蛋白表达水平与其他突变类型无显著差异。⑥6/21例（28.6%）2031C/T多态性患儿伴有严重的关节炎,3/19例（15.8%）无多态性患儿有关节炎表现。⑦28/32例（87.5%）XLA患儿母亲为BTK基因杂合型。结论错义突变可能与确诊年龄较大有关,且某些位点的错义突变可能与较高的外周血B细胞数量和血清IgG水平及正常的BTK蛋白表达水平有关。BTK基因多态性（2031C/T）可能增加关节炎的风险。     

硫胺素焦磷酸激酶缺乏症一家系的临床特点及基因变异分析

目的:探讨一个硫胺素焦磷酸激酶缺乏症(thiamine pyrophosphokinase deficiency,TPKD)家系的临床和基因变异特点。方法:分析TPKD家系的临床表现、影像学特点,对家系成员行全外显子测序。结果:先证者,女,2岁8个月出现发作性共济失调伴肌张力障碍,此后反复发作共济失调7～8次。11岁时...     

Histopathologic and flow cytometric analysis of adenomatous colonic polyps

We evaluated the histopathology, DNA content, and proliferative activity of colonic polyps independently. Paraffin-embedded specimens were used as source material. In each case, additional sections were cut at 3 microns and stained with hematoxylin-eosin and trichrome for histopathologic analysis. For DNA analysis and measurement of proliferative activity, the polyp parts were dissected and the nonpolypoid tissue was discarded. The study was limited to those specimens that were received in our department in the years 1972 and 1977. Of the 104 polyps that were submitted for flow cytometric analysis, 36 could not be analyzed owing to excessive debris or insufficient nuclei. DNA aneuploidy was identified in 32% of the cases, with a higher value noted in larger polyps and in severely dysplastic polyps, but these values were not statistically significant. Multiple adenomas from the same patient often showed different DNA histograms. When analyzed according to the percentage of cells in S phase, no significant difference was found in proliferative activity of polyps according to DNA content or size of the polyps. These results suggest that the diagnostic significance of aneuploidy and proliferative activity in polyps must be interpreted with caution.