Relation of sweat chloride concentration to severity of lung disease in cystic fibrosis

2004 ◽  
Vol 38 (3) ◽  
pp. 204-209 ◽  
Author(s):  
Pamela B. Davis ◽  
Mark D. Schluchter ◽  
Michael W. Konstan
Keyword(s):  
Cystic Fibrosis ◽  
Lung Disease ◽  
Chloride Concentration ◽  
Sweat Chloride

Test for the Concentration of Electrolytes in Cystic Fibrosis of the Pancreas Utilizing Pilocarpine by Iontophoresis, by Lewis E. Gibson and Robert E. Cooke,Pediatrics; 1959;24:545–549

PEDIATRICS ◽  
1998 ◽  
Vol 102 (Supplement_1) ◽  
pp. 230-231
Author(s):  
Victor Chernick
Keyword(s):  
Cystic Fibrosis ◽  
Filter Paper ◽  
Direct Injection ◽  
Heat Stroke ◽  
Chloride Concentration ◽  
Hot Water ◽  
Sweat Test ◽  
High Concentration ◽  
Sweat Chloride ◽  
Plastic Bag

Aim. To develop a method for stimulating sweating that is rapid, painless, and avoids the risk of heat stress. Background. Since the discovery that there is a high concentration of sodium and chloride in the sweat of patients with cystic fibrosis of the pancreas in 1953, the sweat test has been performed by placing the patient's body in a plastic bag with or without hot water bottles to stimulate sweating. This method is unsatisfactory because of complications such as hyperpyrexia and heat stroke. Direct injection of a cholinergic agent intradermally is painful and therefore not practical. Methods. A rheostat with a milliampere meter was constructed at a cost of ∼$7 that allowed the iontophoresis of pilocarpine into the skin using negative and positive (2-cm diameter) electrocardiography electrodes. The positive electrode was placed on the flexor surface of the arm over a filter paper soaked in 0.2 mL of 0.2% pilocarpine nitrate. Current (0.2 mA) was applied for 5 minutes and then sweat was collected onto a preweighed filter paper for 30 minutes. Sweat chloride was determined by a polarographic method. Sweat tests were performed on 25 patients with cystic fibrosis (CF), 17 asymptomatic relatives and 27 control patients. Patients with CF had sweat chloride concentration >80 mEq/L; relatives, 32.5 mEq/L (highest 57 mEq/L); and control subjects, 21.1 mEq/L (highest 60 mEq/L). Conclusions. The iontophoresis of pilocarpine into the skin is a rapid, painless, safe, and reliable method for stimulating sweating and facilitating the determination of sweat chloride concentration.

Negative Effects of Oral Fatty Acid Supplementation on Sweat Chloride in Cystic Fibrosis

PEDIATRICS ◽  
1979 ◽  
Vol 64 (1) ◽  
pp. 50-52
Author(s):  
John D. Lloyd-Still ◽  
Stuart H. Simon ◽  
Hans U. Wessel ◽  
Lewis E. Gibson
Keyword(s):  
Cystic Fibrosis ◽  
Fatty Acid ◽  
Sweat Rate ◽  
Chloride Concentration ◽  
Control Group ◽  
Safflower Oil ◽  
Negative Effects ◽  
Fatty Acid Supplementation ◽  
Acid Supplementation ◽  
Sweat Chloride

Essential fatty acid supplementation with oral safflower oil (1 gm/kg/day) to 11 cystic fibrosis patients (aged 6 months to 14 years) for one year produced no significant change in sweat chloride concentration (mEq/liter) or sweat rate (gm/min/m2). Addition of vitamin E (10 mg/kg/day) to the safflower oil had no effect on sweat chloride concentration or rate compared to placebo. No clinical improvement could be detected compared to a control group. These results do not support previous reports of the effects of fatty acid supplementation on sweat electrolyte concentrations in cystic fibrosis.

scholarly journals Variability of sweat chloride concentration in subjects with cystic fibrosis and G551D mutations

2017 ◽  
Vol 16 (1) ◽  
pp. 36-40 ◽  
Author(s):  
F. Vermeulen ◽  
C. Le Camus ◽  
J.C. Davies ◽  
D. Bilton ◽  
D. Milenković ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Chloride Concentration ◽  
Sweat Chloride

Correlation of Sweat Chloride Concentration with Genotypes in Cystic Fibrosis Patients in Saguenay Lac-Saint-Jean, Quebec, Canada

1998 ◽  
Vol 31 (1) ◽  
pp. 33-36 ◽  
Author(s):  
Marc De Braekeleer ◽  
Christian Allard ◽  
Jean-Pierre Leblanc ◽  
Gervais Aubin ◽  
Fernand Simard
Keyword(s):  
Cystic Fibrosis ◽  
Chloride Concentration ◽  
Sweat Chloride

scholarly journals Case Report: Japanese Siblings of Cystic Fibrosis With a Novel Large Heterozygous Deletion in the CFTR Gene

2022 ◽  
Vol 9 ◽  
Author(s):  
Mayumi Kawase ◽  
Masato Ogawa ◽  
Takayuki Hoshina ◽  
Masumi Kojiro ◽  
Miyuki Nakakuki ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Direct Sequencing ◽  
Chloride Concentration ◽  
Conventional Polymerase Chain Reaction ◽  
Large Deletion ◽  
Heterozygous Deletion ◽  
Real Time Quantitative Pcr ◽  
Sweat Chloride ◽  
Exon 1 ◽  
Fecal Pancreatic Elastase

Cystic fibrosis (CF) is a rare disease in the Japanese. The most common CFTR variant in Japanese CF patients is a large heterozygous deletion that can easily avoid detection by standard gene sequencing methods. We herein report a novel large heterozygous deletion in the CFTR gene in Japanese siblings with CF. A genetic analysis was performed in two patients (9-year-old boy and 5-month-old girl) who were clinically diagnosed with CF because of the positive result for the rapid fecal pancreatic elastase antigen test and the elevation of the sweat chloride concentration. In addition to conventional polymerase chain reaction (PCR) and direct sequencing, multiplex ligation-dependent probe amplification (MLPA) was performed to check for a large deletion and duplication of the CFTR gene. Based on MLPA findings, the breakpoint of heterozygous deletion was identified by real-time quantitative PCR followed by the sequence of the amplified junction fragment. In MLPA, the numbers of the fragments corresponding to exons 1, 16, 17a, and 17b and 234 nt and 747 nt upstream from the translation initiation codon of exon 1 in the CFTR gene and exon 3 in the ASZ1 gene were reduced by almost half. The c.2908+1085_3367+260del7201 variant (exon 16-17b deletion) was identified in one allele. The other allele had a large 137,567-bp deletion from g.117,361,112 (ASZ1 3′ flanking region) to g.117,498,678 (CFTR intron 1) on chromosome 7. Since the deletion variant lacked the entire promoter region of CFTR, CFTR mRNA would not be transcribed from the allele, indicating it to be a novel pathogenic variant causing CF. As large mutations are frequently detected in Japanese CF patients, MPLA can be useful when searching for variants.

scholarly journals Sweat chloride assay by inductively coupled plasma mass spectrometry: a confirmation test for cystic fibrosis diagnosis

2020 ◽  
Vol 412 (25) ◽  
pp. 6909-6916
Author(s):  
Antonella Marvelli ◽  
Beatrice Campi ◽  
Gianfranco Mergni ◽  
Maria Elisa Di Cicco ◽  
Paola Turini ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cystic Fibrosis ◽  
Inductively Coupled Plasma ◽  
Chloride Concentration ◽  
Inductively Coupled ◽  
Sweat Chloride ◽  
Icp Ms ◽  
Relative Standard ◽  
Plasma Mass Spectrometry ◽  
Current Guidelines

Abstract The current guidelines for sweat chloride analysis identify the procedures for sweat collection, but not for chloride assay, which is usually performed by methods originally not aiming at the low concentrations of chloride found in sweat. To overcome this limitation, we set up, characterized, and adopted an original inductively coupled plasma mass spectrometry (ICP-MS) method for sweat chloride determination, which was designed for its easy use in a clinical laboratory. The method was linear in the range 8.5E−3 to 272.0E−3 mM, precision exhibited a relative standard deviation < 6%, and accuracy was in the range 99.7–103.8%. Limit of blank, limit of detection, and limit of quantitation were 2.1 mM, 3.2 mM, and 7.0 mM, respectively, which correspond to real concentrations injected into the mass spectrometer of 3.9E−3 mM for LOD and 8.5E−3 mM for LOQ. At first, the method was tested on 50 healthy volunteers who exhibited a mean chloride concentration of 15.7 mM (25–75th percentile 10.1–19.3 mM, range 2.8–37.4 mM); then, it was used to investigate two patients with suspected cystic fibrosis, who exhibited sweat chloride values of 65.6 mM and 81.2 mM, respectively. Moreover, the method was cross-validated by assaying 50 samples with chloride concentration values in the range 10–131 mM, by both ICP-MS and coulometric titration, which is the technology officially used in Tuscany for cystic fibrosis newborn screening. The reference analytical performances and the relatively low cost of ICP-MS, accompanied by the advantageous cost of a single sweat chloride assay, make this technology the best candidate to provide a top reference method for the quantification of chloride in sweat. The method that we propose was optimized and validated for sweat samples ≥ 75 mg, which is the minimum amount requested by the international protocols. However, the method sensitivity and, in addition, the possibility to reduce the sample dilution factor, make possible the quantification of chloride even in samples weighting < 75 mg that are discarded according to the current guidelines.

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