We report the first case of granulomatous mastitis due to Corynebacterium kroppenstedtii linked to strongly impaired neutrophil responses to Nod2 agonist and a single nucleotide polymorphism within ...the NOD2 gene (SNP13 Leu1007fsinsC) in a heterozygous state. These findings provided the first demonstration of impaired Nod2 function associated with corynebacterial infection.
Immunoassay for human serum hemojuvelin Brasse-Lagnel, Carole; Poli, Maura; Lesueur, Céline ...
Haematologica,
12/2010, Letnik:
95, Številka:
12
Journal Article
Recenzirano
Odprti dostop
Hemojuvelin, a critical regulator of iron homeostasis, is involved in the regulation of hepcidin expression and iron homeostasis. It is expressed both as a membrane-bound form and as a soluble one. ...Serum hemojuvelin can be produced by secretion following furin cleavage or by proteolytic cleavage of the membrane-bound form by matriptase 2 (TMPRSS6). These forms contribute to down-regulation of hepcidin expression upon iron deficiency or hypoxia. This study describes the development and validation of the first enzyme-linked immunosorbent assay for hemojuvelin in human serum.
This assay is based on the use of a recombinant human repulsive guidance molecule-c peptide and a polyclonal antibody against hemojuvelin able to recognize the recombinant peptide and the native soluble hemojuvelin by immunoprecipitation.
The enzyme-linked immunosorbent assay was validated and appeared to be a robust method with intra- and inter-coefficients of variance ranging from 2.6% to 15%. The assay was able to quantify hemojuvelin levels in a control population within a range from 0.88 to 1.14 mg/L. Patients with iron-refractory iron-deficiency anemia with a mutation in the TMPRSS6 gene were found to have lower levels of circulating hemojuvelin than those in healthy patients. The enzyme-linked immunosorbent assay also showed that soluble hemojuvelin levels were significantly higher in patients with anemia of chronic disease than in control individuals.
This enzyme-linked immunosorbent assay has a good specificity and sensitivity for the quantification of soluble hemojuvelin in human serum and could be a valuable aid to understanding the physiological role of this protein.
Chronic granulomatous disease (CGD) results from constitutional inactivating mutations in the CYBB, NCF1, CYBA or NCF2 genes that encode subunits of phagocyte NADPH oxidase. We report the findings of ...molecular analysis of 80 kindred. In 75 unrelated male and 5 female probands, CGD was suspected on the basis of clinical symptoms, and biological samples were referred to our laboratory between 2000 and 2007. Seventy seven patients were found to have mutations in CYBB, NCF1, CYBA or NCF2 (52 different mutations including 31 mutations not previously reported). CYBB was the most frequently mutated gene (58 males and 3 females, 76%). In autosomal recessive forms of the disease, mutations were found in NCF1 (11 patients), NCF2 (3 patients) and CYBA (2 patients). We observed that significantly fewer females were affected by autosomal recessive CGD than expected (2 females/14 males; p=0.002), suggesting that female patients with CGD may be under diagnosed.
We have conducted a case-control study in order to test for an association between 8 intragenic polymorphisms of 5 iron-related genes (transferrin, transferrin receptor1, HFE, frataxin and ...lactoferrin) and Parkinson disease. Comparison of genotypes and allele frequencies did not differ significantly between cases and controls for all studied polymorphisms except the G258S transferrin polymorphism, for which a higher frequency of the G allele was found among cases (p=0.033), particularly among cases with onset older than 60 (p=0.0017) and with negative family history (p=0.022). This finding suggests that genetic variations in the control of iron metabolism may contribute to the pathogenesis of the disease.
Interferon-α (IFN-α) is a nonleukemogenic treatment of polycythemia vera (PV) able to induce cytogenetic remissions. Its use is limited by toxicity, leading to treatment discontinuation in ...approximately 20% of patients. We completed a phase 2 multicenter study of pegylated IFN-α-2a in 40 PV patients. Objectives included evaluation of efficacy, safety, and monitoring of residual disease using JAK2V617F quantification (%V617F). Median follow-up was 31.4 months. At 12 months, all 37 evaluable patients had hematologic response, including 94.6% complete responses (CRs). Only 3 patients (8%) had stopped treatment. After the first year, 35 patients remained in hematologic CR, including 5 who had stopped pegylated IFN-α-2a. Sequential samples for %V617F monitoring, available in 29 patients, showed %V617F decrease in 26 (89.6%). Median %V617F decreased from 45% before pegylated IFN-α-2a to 22.5%, 17.5%, 5%, and 3% after 12, 18, 24, and 36 months, respectively. Molecular CR (JAK2V617F undetectable) was achieved in 7 patients, lasting from 6+ to 18+ months, and persisted after pegylated IFN-α-2a discontinuation in 5. No vascular event was recorded. These results show that pegylated IFN-α-2a yields high rates of hematologic and molecular response in PV with limited toxicity, and could even eliminate the JAK2 mutated clone in selected cases. Available at www.clinicaltrials.gov as #NCT00241241.
Hereditary coproporphyria (HCP), an autosomal dominant acute hepatic porphyria, results from mutations in the gene that encodes coproporphyrinogen III oxidase (CPO). HCP (heterozygous or rarely ...homozygous) patients present with an acute neurovisceral crisis, sometimes associated with skin lesions. Four patients (two families) have been reported with a clinically distinct variant form of HCP. In such patients, the presence of a specific mutation (K404E) on both alleles or associated with a null allele, produces a unifying syndrome in which hematological disorders predominate: ‘harderoporphyria’. Here, we report the fifth case (from a third family) with harderoporphyria. In addition, we show that harderoporphyric patients exhibit iron overload secondary to dyserythropoiesis. To investigate the molecular basis of this peculiar phenotype, we first studied the secondary structure of the human CPO by a predictive method, the hydrophobic cluster analysis (HCA) which allowed us to focus on a region of the enzyme. We then expressed mutant enzymes for each amino acid of the region of interest, as well as all missense mutations reported so far in HCP patients and evaluated the amount of harderoporphyrin in each mutant. Our results strongly suggest that only a few missense mutations, restricted to five amino acids encoded by exon 6, may accumulate significant amounts of harderoporphyrin: D400–K404. Moreover, all other type of mutations or missense mutations mapped elsewhere throughout the CPO gene, lead to coproporphyrin accumulation and subsequently typical HCP. Our findings, reinforced by recent crystallographic results of yeast CPO, shed new light on the genetic predisposition to HCP. It represents a first monogenic metabolic disorder where clinical expression of overt disease is dependent upon the location and type of mutation, resulting either in acute hepatic or in erythropoietic porphyria.
Pulmonary fibrosis is a fatal disease with progressive loss of respiratory function. Defective telomere maintenance leading to telomere shortening is a cause of pulmonary fibrosis, as mutations in ...the telomerase component genes TERT (reverse transcriptase) and TERC (RNA component) are found in 15% of familial pulmonary fibrosis (FPF) cases. However, so far, about 85% of FPF remain genetically uncharacterised.Here, in order to identify new genetic causes of FPF, we performed whole-exome sequencing, with a candidate-gene approach, of 47 affected subjects from 35 families with FPF without TERT and TERC mutations.We identified heterozygous mutations in regulator of telomere elongation helicase 1 (RTEL1) in four families. RTEL1 is a DNA helicase with roles in DNA replication, genome stability, DNA repair and telomere maintenance. The heterozygous RTEL1 mutations segregated as an autosomal dominant trait in FPF, and were predicted by structural analyses to severely affect the function and/or stability of RTEL1. In agreement with this, RTEL1-mutated patients exhibited short telomeres in comparison with age-matched controls.Our results provide evidence that heterozygous RTEL1 mutations are responsible for FPF and, thereby, extend the clinical spectrum of RTEL1 deficiency. Thus, RTEL1 enlarges the number of telomere-associated genes implicated in FPF.
A predisposition for thoracic aortic aneurysms leading to acute aortic dissections can be inherited in families in an autosomal dominant manner. Genome-wide linkage analysis of two large unrelated ...families with thoracic aortic disease followed by whole-exome sequencing of affected relatives identified causative mutations in TGFB2. These mutations-a frameshift mutation in exon 6 and a nonsense mutation in exon 4-segregated with disease with a combined logarithm of odds (LOD) score of 7.7. Sanger sequencing of 276 probands from families with inherited thoracic aortic disease identified 2 additional TGFB2 mutations. TGFB2 encodes transforming growth factor (TGF)-β2, and the mutations are predicted to cause haploinsufficiency for TGFB2; however, aortic tissue from cases paradoxically shows increased TGF-β2 expression and immunostaining. Thus, haploinsufficiency for TGFB2 predisposes to thoracic aortic disease, suggesting that the initial pathway driving disease is decreased cellular TGF-β2 levels leading to a secondary increase in TGF-β2 production in the diseased aorta.
Telomerase reverse transcriptase (TERT) or telomerase RNA (TERC) gene mutation is a major monogenic cause of pulmonary fibrosis. Sequencing of TERT/TERC genes is proposed to patients with familial ...pulmonary fibrosis. Little is known about the possible predictors of this mutation and its impact on prognosis.We retrospectively analysed all the genetic diagnoses made between 2007-2014 in patients with pulmonary fibrosis. We evaluated the prevalence of TERT/TERC disease-associated variant (DAV), factors associated with a DAV, and the impact of the DAV on survival.237 patients with pulmonary fibrosis (153 with familial pulmonary fibrosis, 84 with telomere syndrome features without familial pulmonary fibrosis) were tested for TERT/TERC DAV. DAV was diagnosed in 40 patients (16.8%), including five with non-idiopathic interstitial pneumonia. Prevalence of TERT/TERC DAV did not significantly differ between patients with familial pulmonary fibrosis or with only telomere syndrome features (18.2% versus 16.4%). Young age, red blood cell macrocytosis, and low platelet count were associated with the presence of DAV; the probability of DAV was increased for patients 40-60 years. Transplant-free survival was lower with than without TERT/TERC DAV (4.2 versus 7.2 years; p=0.046).TERT/TERC DAV were associated with specific clinical and biological features and reduced transplant-free survival.
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