Normative growth charts for Shwachman-Diamond syndrome from Italian cohort of 0-8 years old

Shwachman-Diamond syndrome (SDS) is a rare autosomal recessive disorder. Its predominant manifestations include exocrine pancreatic insufficiency, bone marrow failure and skeletal abnormalities. Patients frequently present failure to thrive and susceptibility to short stature. Average birth weight is at the 25th percentile; by the first birthday, >50% of patients drop below the third percentile for height and weight.The study aims at estimating the growth charts for patients affected by SDS in order to give a reference tool helpful for medical care and growth surveillance through the first 8 years of patient's life

HLA-G expression and regulation during Pseudomonas aeruginosa infection in cystic fibrosis patients

Deregulated immune response fails to control biofilm-forming bacteria, as Pseudomonas aeruginosa, in the lungs of cystic fibrosis (CF) patients. HLA-G is an immune-modulatory molecule involved in respiratory diseases and infections

CFTR function is impaired in a subset of patients with pancreatitis carrying rare CFTR variants

Background: Many affected by pancreatitis harbor rare variants of the cystic fibrosis (CF) gene, CFTR, which encodes an epithelial chloride/bicarbonate channel. We investigated CFTR function and the effect of CFTR modulator drugs in pancreatitis patients carrying CFTR variants. Methods: Next-generation sequencing was performed to identify CFTR variants. Sweat tests and nasal potential difference (NPD) assays were performed to assess CFTR function in vivo. Intestinal current measurement (ICM) was performed on rectal biopsies. Patient-derived intestinal epithelial monolayers were used to evaluate chloride and bicarbonate transport and the effects of a CFTR modulator combination: elexacaftor, tezacaftor and ivacaftor (ETI). Results: Of 32 pancreatitis patients carrying CFTR variants, three had CF-causing mutations on both alleles and yielded CF-typical sweat test, NPD and ICM results. Fourteen subjects showed a more modest elevation in sweat chloride levels, including three that were provisionally diagnosed with CF. ICM indicated impaired CFTR function in nine out of 17 non-CF subjects tested. This group of nine included five carrying a wild type CFTR allele. In epithelial monolayers, a reduction in CFTR-dependent chloride transport was found in six out of 14 subjects tested, whereas bicarbonate secretion was reduced in only one individual. In epithelial monolayers of four of these six subjects, ETI improved CFTR function. Conclusions: CFTR function is impaired in a subset of pancreatitis patients carrying CFTR variants. Mutations outside the CFTR locus may contribute to the anion transport defect. Bioassays on patient-derived intestinal tissue and organoids can be used to detect such defects and to assess the effect of CFTR modulators.</p

CFTR function is impaired in a subset of patients with pancreatitis carrying rare CFTR variants

Background: Many affected by pancreatitis harbor rare variants of the cystic fibrosis (CF) gene, CFTR, which encodes an epithelial chloride/bicarbonate channel. We investigated CFTR function and the effect of CFTR modulator drugs in pancreatitis patients carrying CFTR variants. Methods: Next-generation sequencing was performed to identify CFTR variants. Sweat tests and nasal potential difference (NPD) assays were performed to assess CFTR function in&nbsp;vivo. Intestinal current measurement (ICM) was performed on rectal biopsies. Patient-derived intestinal epithelial monolayers were used to evaluate chloride and bicarbonate transport and the effects of a CFTR modulator combination: elexacaftor, tezacaftor and ivacaftor (ETI). Results: Of 32 pancreatitis patients carrying CFTR variants, three had CF-causing mutations on both alleles and yielded CF-typical sweat test, NPD and ICM results. Fourteen subjects showed a more modest elevation in sweat chloride levels, including three that were provisionally diagnosed with CF. ICM indicated impaired CFTR function in nine out of 17 non-CF subjects tested. This group of nine included five carrying a wild type CFTR allele. In epithelial monolayers, a reduction in CFTR-dependent chloride transport was found in six out of 14 subjects tested, whereas bicarbonate secretion was reduced in only one individual. In epithelial monolayers of four of these six subjects, ETI improved CFTR function. Conclusions: CFTR function is impaired in a subset of pancreatitis patients carrying CFTR variants. Mutations outside the CFTR locus may contribute to the anion transport defect. Bioassays on patient-derived intestinal tissue and organoids can be used to detect such defects and to assess the effect of CFTR modulators

GENETIC ANALYSIS OF THE SBDS GENE AMONG NON-ITALIAN PATIENTS

The SBDS mRNA is widely expressed in many tissues and its mutations cause a wide variety of abnormalities and symptoms, so the diagnosis is not always immediately obvious. The screening for mutations in the SBDS gene started, in our laboratory, in 2003. In a period of 13 years we analyzed, after obtained informed consent, a total of 174 families having one suspected SDS patient. Part of the 174 families were of non-Italian origin: these samples arrived to our laboratory by direct communications from family doctors or by the Genetic Testing Registry (GTR\uae). GTR provides a central location for voluntary submission of genetic test information by providers. As providers of: confirmation of research findings, sequence analysis, genetic counseling, prenatal testing, mutation-specific/carrier testing, we analyzed a total of 28 families from the following nationalities: Australia, Bangladesh, China, Egypt, India, Latvia, Lebanon, Libya, Morocco, Pakistan, Philippines, Romania, Santo Domingo,Turkey, Ukraine, Vietnam. Among the 25 families, we characterized, as SDS, 8 patients. The median (range)\ua0age at diagnosis\ua0was 2.8 (0.1-7) years. The clinical status at diagnosis appears very similar between Italian and non-Italian patients. Pancreatic dysfunctions is present in the majority of subjects as well as hematologic abnormalities and infections. The SDS alleles reflect the frequencies observed in Italy. Two mutations are not present in the Italian SDS patients: the missense mutation c.523C>T in exon 4, found in homozygosis and the c.307_308delCA, a frame shift deletion in the exon 3 leading to a premature stop codon. The SDS is described in even more geographic area of the world among different ethnic population

Multilinear Regression Analysis of Sweat Secretion Volumes in Cystic Fibrosis Patients

Personalized medicine approach in cystic fibrosis (CF) is focusing on detection of cystic fibrosis transmembrane conductance regulator (CFTR) function in single patients and standardized outcomes for CFTR function in vivo. We applied Optical Sweat Rate Beta Adrenergic (OSRBA) test for measuring sweat rates in individual human sweat glands. The results were analyzed according to a multilinear regression model in non- CF, healthy carriers (HTZ), CF patients; two groups of these were tested during treatment with CFTR modulators such as lumacaftor/ivacaftor (Orkambi) or PTC 124 (Ataluren). We found that different sets of statistically significant coefficients of the multilinear regression of the volume of sweat secretory glands characterize different CFTR genotype as well as different responses to different pharmacological treatments

HLA-G expression and regulation duringPseudomonas aeruginosainfection in cystic fibrosis patients

BACKGROUND: Deregulated immune response fails to control biofilm-forming bacteria, as Pseudomonas aeruginosa, in the lungs of cystic fibrosis (CF) patients. HLA-G is an immune-modulatory molecule involved in respiratory diseases and infections. MATERIALS & METHODS: HLA-G mRNA and protein were analyzed in plasma and exhaled breath condensate from CF patients undergoing intravenous antibiotic treatment, CF cell line and murine model. RESULTS: Therapy normalizes HLA-G plasmatic in CF patients suggesting a systemic anti-inflammatory role while in CF airway system, higher expression of HLA-G is associated with P. aeruginosa infection. CF cell line and murine model expressed higher HLA-G molecules in the presence of P. aeruginosa. CONCLUSION: Plasmatic and lung HLA-G expression suggest a role in reducing systemic inflammation and supporting P. aeruginosa infectio

Optical Measurements of Sweat for in Vivo Quantification of CFTR Function in Individual Sweat Glands

Optical measurement of CFTR-dependent sweat secretion stimulated by a beta-adrenergic cocktail (C-phase) vs. CFTR-independent sweat secretion induced by methacholine (M-phase) can discriminate cystic fibrosis (CF) patientts from controls and healthy carriers by the ratio of sweat rate in the C-phase vs. the M-phase (C/M ratio). However, image analysis is experimentally demanding and time-consuming. Here, sweat droplet number (SDN) in the C-phase, corresponding to the number of sweat-secreting glands, was a statistically significant predictor for detecting the effects of CFTR-targeted therapy. We show that in 44 non-CF subjects and 110 CF patients, SDN in the C-phase provides a linear readout of CFTR function that is more sensitive than that using the C/M ratio. In CF patients, increased SDN in the C-phase during treatment with (LUMA/IVA) was associated with a trend toward improved lung function (FEV1). Our method is suitable for multicenter monitoring of the effects of CFTR modulators

HLA-G expression and regulation during Pseudomonas aeruginosa infection in cystic fibrosis patients.

Background Deregulated immune response fails to control biofilm-forming bacteria, as P.aeruginosa, in the lung of Cystic Fibrosis (CF) patients. HLA-G is an immune-modulatory molecule involved in respiratory diseases and infections. Methods HLA-G mRNA and protein were analyzed in plasma and exhaled breath condensate from CF patients undergoing intravenous antibiotic treatment, CF cell line and murine model. Results Therapy normalizes HLA-G plasmatic in CF patients suggesting a systemic anti-inflammatory role while in CF airway system, higher expression of HLA-G is associated with P.aeruginosa infection. CF cell line and murine model expressed higher HLA-G molecules in the presence of P.aeruginosa. Conclusions Plasmatic and lung HLA-G expression suggest a role in reducing systemic inflammation and supporting P.aeruginosa infection

Whole exome sequencing discloses heterozygous variants in the DNAJC21 and EFL1 genes but not in SRP54 in 6 out of 16 patients with Shwachman-Diamond Syndrome carrying biallelic SBDS mutations

Whole exome sequencing discloses heterozygous variants in the DNAJC21 and EFL1 genes but not in SRP54 in 6 out of 16 patients with Shwachman-Diamond Syndrome carrying biallelic SBDS mutation