Search

Aims: Transthyretin cardiac amyloidosis (ATTR‐CM) may be an underestimated cause of heart failure among geriatric patients and represent a unique phenotype and prognostic profile. Methods and results: This retrospective, observational, cohort study characterizes cardiac and extracardiac disorders at diagnosis and assesses prognosis among ATTR‐CM patients based on age (geriatric vs. non‐geriatric) and amyloidosis subtype (wild type, ATTRwt and hereditary, ATTRv). In total, 943 patients with ATTR‐CM were included, of which 306 had ATTRv and 637 had ATTRwt. Among these, 331 (35.1%) were non‐geriatric (<75 years), and 612 (64.9%) were geriatric (≥75 years). The population exhibited conduction abnormalities, atrial fibrillation and ischaemic heart disease that progressively deteriorated with age. Among ATTRwt patients, peripheral neuropathy, neurovegetative symptoms, and hearing loss were present across all age groups, but reports of carpal tunnel symptoms or surgery decreased with age. Conversely, among ATTRv patients, reports of extracardiac symptoms increased with age and Val122ILe mutation was highly prevalent among geriatric patients. The 3‐year survival was higher among non‐geriatric ATTR‐CM patients (76%) than geriatric patients (55%) and predictors of 3‐year mortality differed. Notably, predictors identified among geriatric patients were alkaline phosphatase (ALP) (HR = 1.004, 95% CI: [0.001–1.100)], troponin T hs (HR = 1.005, 95% CI: [1.001–1.120)] and tricuspid insufficiency (HR = 1.194, 95% CI: [1.02–1.230)]. Whereas, among non‐geriatric patients, NT‐proBNP (HR = 1.002, 95% CI: [1.02–1.04], global longitudinal strain (HR = 0.95, 95% CI: [0.922–0.989], and glomerular filtration rate (HR = 0.984, 95% CI: [0.968–1.00) were identified. We propose a 3‐stage prognostic staging system combining troponin T hs (≥44 ng/L) and ALP levels (≥119 UI/L). In the geriatric population, this model discriminated survival more precisely than the National Amyloidosis Centre staging, particularly for classifying between stage 1 (82%), stage 2 (50%) and stage 3 (32%) for ATTRv and ATTRwt. Conclusions: These diagnostic and prognostic indicators, along with ATTR subtype, highlight the distinct characteristics of this important, geriatric ATTR‐CM patient group. Recognizing these mortality markers can be valuable for geriatricians to improve the prognostic quality management of geriatric patients with ATTR‐CM. [ABSTRACT FROM AUTHOR]

I ANK1 i is one of the most frequently mutated genes in hereditary spherocytosis (HS) in European countries and encodes the protein Ankyrin-1 which is a major membrane erythrocyte protein linking horizontal protein network to the vertical one. Briefly, total RNA was purified from cultured cells transfected with empty plasmid, minigene containing partial wild-type (WT) or mutated I ANK1 i intron, prior natural I n i + 1 exon and partial I n i + 1 intron. Molecular analysis revealed the presence of an I ANK1 i intronic variation at heterozygous state: NM 020476 ( I ANK1 i ): c.1405-9G>A (intron 13) in patient 1 and c.5097-33G>A (intron 38) in patient 2. [Extracted from the article]

Aims: Iron deficiency (ID) is common in patient with chronic heart failure (HF) and has been widely studied. In contrast, data concerning ID in cardiac amyloidosis (CA) are limited. Amyloidosis is a severe and fatal systemic disease, characterized by an accumulation of amyloid fibrils in various tissues/organs, including nerves, kidneys, gastrointestinal tract, and heart. Amyloid deposits in the heart eventually cause HF. The main subtypes of CA are light chain (AL), hereditary transthyretin (ATTRv), and wild‐type transthyretin (ATTRwt). We performed this study to determine the prevalence, clinical outcome (all‐cause mortality), and determinants of ID among the three main subtypes of CA. Methods and results: Iron deficiency status were analysed in 816 CA patients enrolled at the French Referral Centre for Cardiac Amyloidosis: 271 (33%) had AL, 164 (20%) ATTRv, and 381 (47%) ATTRwt. ID affected 49% of CA patients, 45% with AL, 58% with ATTRv, and 48% with ATTRwt. We identified ATTR status (ATTRv P = 0.003, ATTRwt P = 0.037), diabetes (P = 0.003), aspirin treatment (P = 0.009), haemoglobin levels (P = 0.006), and altered global longitudinal strain (P = 0.02) as independent ID determinants. There is no difference in all‐cause mortality considering ID status. Conclusions: Iron deficiency is common in patients with CA, irrespective of the subtype. Patients seem more likely to have ID if diagnosed with ATTR, if diabetic, and/or treated with aspirin. In CA, the benefit of intravenous iron therapy, for ID, on morbidity and mortality needs further study. [ABSTRACT FROM AUTHOR]

Aims: Cardiac amyloidosis (CA) has a poor prognosis which is aggravated by diagnostic delay. Amyloidosis extracardiac and cardiac events (AECE and ACE) may help improve CA diagnosis and typing. The aim of this study was to compare AECE and ACE between different CA types and assess their relationship with survival. Methods and results: This retrospective cohort study conducted in France from June 2008 to May 2019, at the Henry Mondor Hospital. This cohort included 983 patients with CA. Mean age at inclusion was 73.1 ± 11.4 years, 726 (75.1%) were male and the mean body mass index was 24.5 ± 4.1 kg/m2. Among them, 321 had immunoglobulin light chain (AL) amyloidosis, 434 had wild‐type transthyretin (ATTRwt), and 212 had hereditary transthyretin (ATTRv). The first AECE and/or ACE occurred at a mean age of 63 ± 11 years for AL and ATTRv, and 70 ± 12 years for ATTRwt (P < 0.01). The median (Q1–Q3) delay between declaration of the first events and diagnosis varied from 11.1 (5.9; 34.8) months for AL to 92.2 (39.0; 174.7) months for ATTRwt (P < 0.01). The nature of the onset of AECE or ACE varied based on amyloidosis type, heart failure symptoms for AL (26%) and integumentary symptoms for ATTRv with cardiologic or mixed phenotype (39%) and ATTRwt (42%). In AL and ATTRwt, a short delay between the onset of the first AECE or ACE and diagnosis was associated with reduced survival rate (log‐rank test P‐value <0.01). Conclusions: This study highlights the impact of amyloidosis type and evolution on diagnostic delay and on prognosis. Physicians must be aware and vigilant in front of extracardiac and cardiac events to considerably improve early diagnosis of amyloidosis. [ABSTRACT FROM AUTHOR]

Mutations in the gene encoding surfactant protein C (SP‐C) cause interstitial lung disease (ILD), and glucocorticosteroid (GC) treatment is the most recognized therapy in children. We aimed to decipher the mechanisms behind successful GC treatment in twins carrying a BRICHOS c.566G > A (p.Cys189Tyr) mutation in the SP‐C gene (SFTPC). Methods: The twins underwent bronchoscopy before and after GC treatment and immunoblotting analysis of SP‐C proprotein (proSP‐C) and SP‐C mature in bronchoalveolar fluid (BALF). Total RNA was extracted and analysed using quantitative real‐time PCR assays. In A549 cells, the processing of mutated protein C189Y was studied by immunofluorescence and immunoblotting after heterologous expression of eukaryotic vectors containing wild type or C189Y mutant cDNA. Results: Before treatment, BALF analysis identified an alteration of the proSP‐C maturation process. Functional study of C189Y mutation in alveolar A549 cells showed that pro‐SP‐CC189Y was retained within the endoplasmic reticulum together with ABCA3. After 5 months of GC treatment with clinical benefit, the BALF analysis showed an improvement of proSP‐C processing. SFTPC mRNA analysis in twins revealed a decrease in the expression of total SFTPC mRNA and a change in its splicing, leading to the expression of a second shorter proSP‐C isoform. In A549 cells, the processing and the stability of this shorter wild‐type proSP‐C isoform was similar to that of the longer isoform, but the half‐life of the mutated shorter isoform was decreased. These results suggest a direct effect of GC on proSP‐C metabolism through reducing the SFTPC mRNA level and favouring the expression of a less stable protein isoform. [ABSTRACT FROM AUTHOR]

Aims: Hereditary (ATTRv) and wild‐type (ATTRwt) transthyretin amyloidosis are severe and fatal systemic diseases, characterised by amyloid fibrillar accumulation principally in the heart or peripheral nerves (or both). Since 2012, tafamidis has been used in France to treat patients with ATTRv with neuropathy (alone or combined with cardiomyopathy). Recently, the Phase III ATTR‐ACT trial showed that tafamidis decreased the relative risk of mortality in ATTR amyloidosis with cardiomyopathy. The aims of this study were to assess the clinical characteristics of ATTR amyloidosis in a real‐life population in comparison to the population included in the ATTR‐ACT trial and to assess the impact of tafamidis treatment on major cardiovascular outcome (MCO)‐free survival time without cardiac decompensation, heart transplant, or death. Methods and results: From June 2008 to November 2018, 648 patients with ATTR amyloidosis (423 ATTRwt and 225 ATTRv) consecutively referred to the French Referral Center for cardiac amyloidosis were included. A total of 467 (72%) patients matched the inclusion criteria of the ATTR‐ACT trial. For the 631 patients with cardiomyopathy, tafamidis treatment was associated with a longer median MCO‐free survival time (n = 98): 1565 (1010–2400) days vs. 771 (686–895) days without treatment (log‐rank P < 0.001). This association was confirmed after considering confounding factors (age at inclusion, N‐terminal pro‐B‐type natriuretic peptide and amyloidosis type) with a propensity score (hazard ratio 0.546; P = 0.0132). Conclusion: In a large cohort of ATTRwt and ATTRv patients, representative of the inclusion criteria of the ATTR‐ACT trial, the present results show an association between tafamidis treatment and a lower occurrence of cardiovascular outcomes in a real‐life population. [ABSTRACT FROM AUTHOR]

Severe chronic rhinosinusitis in children should alert clinicians and extensive CFTR genotyping should be performed. We propose that thorough clinical and functional assessment in severe chronic rhinosinusitis is valuable to discover rare mutations which could be treated by CFTR correctors to postpone pulmonary infection. [ABSTRACT FROM AUTHOR]

Abstract: Molecules correcting the trafficking (correctors) and gating defects (potentiators) of the cystic fibrosis causing mutation c.1521_1523delCTT (p.Phe508del) begin to be a useful treatment for CF patients bearing p.Phe508del. This mutation has been identified in different genetic contexts, alone or in combination with variants in cis. Until now, 21 exonic variants in cis of p.Phe508del have been identified, albeit at a low frequency. The aim of this study was to evaluate their impact on the efficacy of CFTR‐directed corrector/potentiator therapy (Orkambi). The analysis by minigene showed that two out of 15 cis variants tested increased exon skipping (c.609C > T and c.2770G > A). Four cis variants were studied functionally in the absence of p.Phe508del, one of which was found to be deleterious for protein maturation c.1399C > T (p.Leu467Phe). In the presence of p.Phe508del, this variant was the only to prevent the response to Orkambi treatment. This study showed that some patients carrying p.Phe508del complex alleles are predicted to poorly respond to corrector/potentiator treatments. Our results underline the importance to validate treatment efficacy in the context of complex alleles. [ABSTRACT FROM AUTHOR]

Key Clinical Message In vitro functional tests aimed to investigate CFTR dysfunction appear critical to help elucidate the functional impact of new variants of uncertain clinical significance and solve inconclusive cases, especially in early deceased newborns. [ABSTRACT FROM AUTHOR]

Background and Purpose: Pulmonary disease is the main cause of morbidity and mortality in cystic fibrosis (CF) patients due to exacerbated inflammation. To date, the only anti-inflammatory drug available to CF patients is high-dose ibuprofen, which can slow pulmonary disease progression, but whose cyclooxygenase-dependent digestive adverse effects limit its clinical use. Here we have tested sulindac, another non-steroidal anti-inflammatory drug with an undefined anti-inflammatory effect in CF airway epithelial cells.Experimental Approach: Using in vitro and in vivo models, we NF-κB activity and IL-8 secretion. In HeLa-F508del cells, we performed luciferase reporter gene assays in order to measure i) IL-8 promoter activity, and ii) the activity of synthetic promoter containing NF-κB responsive elements. We quantified IL-8 secretion in airway epithelial CFBE cells cultured at an air-liquid interface and in a mouse model of CF.Key Results: Sulindac inhibited the transcriptional activity of NF-κB and decreased IL-8 transcription and secretion in TNF-α stimulated CF cells via a cyclooxygenase-independent mechanism. This effect was confirmed in vivo in a mouse model of CF induced by intra-tracheal instillation of LPS, with a significant decrease of the induction of mRNA for MIP-2, following treatment with sulindac.Conclusion and Implications: Overall, sulindac decrease lung inflammation by a mechanism independent of cycolooxygenase. This drug could be beneficially employed in CF. [ABSTRACT FROM AUTHOR]

ABSTRACT Cystic fibrosis may be revealed by nasal polyposis ( NP) starting early in life. We performed cystic fibrosis transmembrane conductance regulator ( CFTR) DNA and m RNA analyses in the family of a 12-year-old boy presenting with NP and a normal sweat test. Routine DNA analysis only showed the heterozygous c.2551 C> T (p. Arg851*) mutation in the child and the father. m RNA analysis showed partial exon skipping due to c.2551 C> T and a significant increase in total CFTR m RNA in the patient and the mother, which was attributable to the heterozygous c. −2954 G> A variant in the distant promoter region, as demonstrated by in vitro luciferase assays. The 5′ rapid amplification of cDNA ends analysis showed the presence of a novel transcript, where the canonical exon 1 was replaced by an alternative exon called 1a- Long. This case report could represent the first description of a CFTR-related disorder associated with the presence of a 5′ alternative, probably nonfunctional transcript, similar to those of fetal origin. [ABSTRACT FROM AUTHOR]

ABSTRACT With the increased number of identified nucleotide sequence variations in genes, the current challenge is to classify them as disease causing or neutral. These variants of unknown clinical significance can alter multiple processes, from gene transcription to RNA splicing or protein function. Using an approach combining several in silico tools, we identified some exons presenting weaker splicing motifs than other exons in the Cystic Fibrosis Transmembrane conductance Regulator ( CFTR) gene. These exons exhibit higher rates of basal skipping than exons harboring no identifiable weak splicing signals using minigene assays. We then screened 19 described mutations in three different exons, and identified exon-skipping substitutions. These substitutions induced higher skipping levels in exons having one or more weak splicing motifs. Indeed, this level remained under 2% for exons with strong splicing motifs and could reach 40% for exons having at least one weak motif. Further analysis revealed a functional exon splicing enhancer within exon 3 that was associated with the SR protein SF2/ ASF and whose disruption induced exon skipping. Exon skipping was confirmed in vivo in two nasal epithelial cell brushing samples. Our approach, which point out exons with some splicing signals weaknesses, will help spot splicing mutations of clinical relevance. [ABSTRACT FROM AUTHOR]

ABSTRACT The correction of premature termination codons ( PTCs) by agents that promote readthrough represents a promising emerging tool for the treatment of many genetic diseases. The efficiency of the treatment, however, varies depending on the stop codon itself and the amount of correctible transcripts related to the efficiency of nonsense-mediated decay. In the current study, a screen by in vitro minigene assay of all six PTCs described in exon 15 of the CFTR gene demonstrated alternative splicing to differing degrees for five of them. Of the five, PTC mutations c.2537 G> A (p. Trp846* UAG) and c.2551 C> T (p. Arg851*) cause the greatest proportion of transcripts lacking exon 15; both mutations altering exonic splicing regulatory elements. In order to increase the amount of full-length transcripts, different pharmacological treatments were performed showing both negative and positive effects on exon inclusion for the same mutation. Therefore, the total amount of transcripts together with the splicing profile should be assessed to anticipate and improve efficacy of readthrough therapy. [ABSTRACT FROM AUTHOR]

Genotype-phenotype correlations in cystic fibrosis (CF) may be difficult to establish because of phenotype variability, which is associated with certain CF transmembrane conductance regulator ( CFTR) gene mutations and the existence of complex alleles. To elucidate the clinical significance of complex alleles involving p.Gly149Arg, p.Asp443Tyr, p.Gly576Ala, and p.Arg668Cys, we performed a collaborative genotype-phenotype correlation study, collected epidemiological data, and investigated structure-function relationships for single and natural complex mutants, p.[Gly576Ala;Arg668Cys], p.[Gly149Arg;Gly576Ala;Arg668Cys], and p.[Asp443Tyr;Gly576Ala;Arg668Cys]. Among 153 patients carrying at least one of these mutations, only three had classical CF and all carried p.Gly149Arg in the triple mutant. Sixty-four had isolated infertility and seven were healthy individuals with a severe mutation in trans, but none had p.Gly149Arg. Functional studies performed on all single and natural complex mutants showed that (1) p.Gly149Arg results in a severe misprocessing defect; (2) p.Asp443Tyr moderately alters CFTR maturation; and (3) p.Gly576Ala, a known splicing mutant, and p.Arg668Cys mildly alter CFTR chloride conductance. Overall, the results consistently show the contribution of p.Gly149Arg to the CF phenotype, and suggest that p.[Arg668Cys], p.[Gly576Ala;Arg668Cys], and p.[Asp443Tyr;Gly576Ala;Arg668Cys] are associated with CFTR-related disorders. The present study emphasizes the importance of comprehensive genotype-phenotype and functional studies in elucidating the impact of mutations on clinical phenotype. Hum Mutat 33:1557-1565, 2012. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Abbreviations chILD childhood interstitial lung disease GM-CSF granulocyte-macrophage colony-stimulating factor HRCT high-resolution computed tomography NEHI neuroendocrine cell hyperplasia of infancy Childhood interstitial lung disease (chILD) is a heterogeneous group of rare respiratory disorders. This could explain the frequent respiratory disorders reported in other patients with 48,XXYY syndrome, although they were not described as chILD in these publications.[2] Our overall conclusion is to recommend further investigations using HRCT in 48,XXYY patients with respiratory symptoms. [Extracted from the article]

Cystic fibrosis (CF) is mainly caused by mutations that interfere with the biosynthetic folding of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel. The aim of this study was to determine the mechanism of dysfunction of a disease-causing mutation associated with variable phenotypes. In order to attain these objectives, we studied the effect of the p.L206W mutation on CFTR protein production and function, and we examined the genotype-phenotype correlation of [p.L206W]+[p.F508del] patients. We showed that p.L206W is a processing (class II) mutation since the CFTR biosynthetic pathway was severely impaired, whereas single-channel measurements indicated ion conductance similar to the wild-type protein. These data raise the larger question of the phenotypic variability of class II mutants, including p.F508del. Since multiple potential partners could modify the processing of the CFTR protein during its course to the cell surface, environmental and other genetic factors might contribute to this variability. Hum Mutat 25:360-371, 2005. © 2005 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

The thiazolidinone CFTRinh-172 was identified recently as a potent and selective blocker of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl− channel. Here, we characterized the CFTRinh-172 inhibition mechanism by patch-clamp and short-circuit analysis using cells stably expressing wild-type and mutant CFTRs. CFTRinh-172 did not alter CFTR unitary conductance (8 pS), but reduced open probability by >90% with Ki&ap;0.6 μM. This effect was due to increased mean channel closed time without changing mean channel open time. Short-circuit current experiments indicated similar CFTRinh-172 inhibitory potency (Ki&ap;0.5 μM) for inhibition of Cl− current in wild-type, G551D, and G1349D CFTR; however, Ki was significantly reduced to 0.2 μM for ΔF508 CFTR. Our studies provide evidence for CFTR inhibition by CFTRinh-172 by a mechanism involving altered CFTR gating. [Copyright &y& Elsevier]

1. This study compares the effect of three chemically unrelated cystic fibrosis transmembrane conductance regulator (CFTR) activators on epithelial cell monolayers expressing the G551D-CFTR mutant. 2. We measured Cl(-) transport as the amplitude of short-circuit current in response to the membrane permeable cAMP analogue 8-(4-chlorophenylthio)adenosine-3'-5'-cyclic monophosphate (CPT-cAMP) alone or in combination with a CFTR opener. The correction of G551D-CFTR defect was quantified by comparison with maximal activity elicited in cells expressing wild type CFTR. To this end we used Fisher rat thyroid (FRT) cells transfected with wild type or G551D CFTR, and primary cultures of human nasal epithelial cells. 3. In both types of epithelia, cAMP caused activation of Cl(-) transport that was inhibited by glibenclamide and not by 4,4'-diisothiocyanato-stilbene-2,2'-disulfonic acid. After normalising for CFTR expression, the response of FRT-G551D epithelia was 1% that of wild type monolayers. 4. Addition of genistein (10-200 micro M), but not of 8-cyclopentyl-1,3-dipropylxanthine (CPX, 1-100 micro M) or of the benzo[c]quinolizinium MPB-07 (10-200 micro M) to FRT-G551D epithelia pre-treated with cAMP, stimulated a sustained current that at maximal genistein concentration corresponded to 30% of the response of wild type epithelia. 5. The genistein dose-response curve was bell-shaped due to inhibitory activity at the highest concentrations. The dose-dependence in G551D cells was shifted with respect to wild type CFTR so that higher genistein concentrations were required to observe activation and inhibition, respectively. 6. On human nasal epithelia the correction of G551D-CFTR defective conductance obtained with genistein was 20% that of wild type. The impressive effect of genistein suggests that it might correct the Cl(-) transport defect on G551D patients. [ABSTRACT FROM AUTHOR]

The properties of a protein-kinase-A(PKA)-activated Cl--conductive pathway(s) in alkaline phosphatase-enriched microsomes from the rat inner medulla (IMV) were investigated. Transcripts of cystic fibrosis transmembrane regulator (CFTR) were detected by, reverse transcription/polymerase analysis of total RNA from the inner medulla, while immunoblot analysis using anti-CFTR antibodies detected a 170-kDa protein in the IMV. The PKA Cl--conductive pathway(s) was studied by measuring the rate of valinomycin-induced microsomal swelling by light scattering, PKA increased the rate of valinomycin-induced swelling, of vesicles consistent with the presence of Cl--conductive pathway(s). The pharmacological properties and anion selectivity of the PKA-activated Cl--conductive pathway(s) were similar to those of the CFTR Cl- channel. Our results show that a CFTR Cl- channel and possibility another cAMP-activated pathway(s) may participate in Cl- secretion in the rat inner medulla. [ABSTRACT FROM AUTHOR]