scholarly journals Newborn Screening for Cystic Fibrosis: Infant and Laboratory Factors Affecting Successful Sweat Test Completion

2020 ◽  
Vol 7 (1) ◽  
pp. 1
Author(s):  
Ambika Shenoy ◽  
Dina Spyropoulos ◽  
Kathleen Peeke ◽  
Dawn Smith ◽  
Michael Cellucci ◽  
...  

Newborn screening (NBS) for Cystic Fibrosis (CF) has revolutionized the diagnosis of this inherited disease. CF NBS goals are to identify, diagnose, and initiate early CF treatment to attain better health outcomes. Abnormal CF NBS infants require diagnostic analysis via sweat chloride testing (ST). During ST, insufficient sweat volume collection causes a “quantity not sufficient” (QNS) test result and may delay CF diagnosis. The CF Foundation recommends QNS rates <10% for infants <3 months, but many CF Centers experience difficulties meeting this standard. Our quality improvement (QI) study assessed infant and laboratory factors contributing to ST success and QNS rates from 2017–2019. Infants’ day of life (DOL) at successful ST completion was analyzed according to infant factors (birth weight (BW), gestational age, ethnicity, and sex). Laboratory factors and procedures affecting ST outcomes were also reviewed. At our institution, BW and gestational age were the infant factors found to significantly affect DOL at ST completion. ST education, reduced number of laboratory technicians, and direct observation during ST completion also improved ST success rates. This study supports QI measures and partnerships between CF centers and laboratory staff to identify and improve ST QNS rates while sustaining practices to ensure timely CF diagnostic testing.

2014 ◽  
Author(s):  
Michael J Stephen

Cystic fibrosis (CF) is an autosomal recessive disease characterized by an elevated sweat chloride level, diffuse bronchiectasis, and pancreatic exocrine deficiency. It is the most common lethal inherited disease in whites. Most patients present at birth or early childhood, although later diagnoses are not infrequent. Once CF was uniformly fatal at an early age, but advances in nutrition, airway clearance, and infection management have led to an average survival of 37 years. The newest aspect of care is the advent of protein modulators, which may increase life expectancy even further. This chapter discusses the epidemiology, genetics, pathophysiology and pathogenesis, diagnosis, differential diagnosis, and treatment of CF. The definition, epidemiology, etiology, pathogenesis, diagnosis, management, and prognosis of non-CF bronchiectasis are also covered. Figures illustrate normal and abnormal CF transmembrane conductance regulators, the vicious cycle hypothesis of lung injury, rates of respiratory germs by age, the diagnosis of CF, the therapeutics pipeline for CF, forced expiratory volume in 1 second lung function percent predicted versus body mass index, and the median predicted survival age of patients with CF. A chest x-ray and chest computed tomographic scan of CF are also provided. Tables outline the most common CF mutations in 2011, class mutations of CF, a mnemonic for acute exacerbations of CF, the diagnosis of CF-related diabetes in a stable patient, sweat test values, and the differential diagnosis of bronchiectasis.This chapter contains 9 highly rendered figures, 6 tables, 143 references, 1 teaching slide set, and 5 MCQs.


2014 ◽  
Author(s):  
Michael J Stephen

Cystic fibrosis (CF) is an autosomal recessive disease characterized by an elevated sweat chloride level, diffuse bronchiectasis, and pancreatic exocrine deficiency. It is the most common lethal inherited disease in whites. Most patients present at birth or early childhood, although later diagnoses are not infrequent. Once CF was uniformly fatal at an early age, but advances in nutrition, airway clearance, and infection management have led to an average survival of 37 years. The newest aspect of care is the advent of protein modulators, which may increase life expectancy even further. This chapter discusses the epidemiology, genetics, pathophysiology and pathogenesis, diagnosis, differential diagnosis, and treatment of CF. The definition, epidemiology, etiology, pathogenesis, diagnosis, management, and prognosis of non-CF bronchiectasis are also covered. Figures illustrate normal and abnormal CF transmembrane conductance regulators, the vicious cycle hypothesis of lung injury, rates of respiratory germs by age, the diagnosis of CF, the therapeutics pipeline for CF, forced expiratory volume in 1 second lung function percent predicted versus body mass index, and the median predicted survival age of patients with CF. A chest x-ray and chest computed tomographic scan of CF are also provided. Tables outline the most common CF mutations in 2011, class mutations of CF, a mnemonic for acute exacerbations of CF, the diagnosis of CF-related diabetes in a stable patient, sweat test values, and the differential diagnosis of bronchiectasis.This chapter contains 9 highly rendered figures, 6 tables, 143 references, 1 teaching slide set, and 5 MCQs.


2017 ◽  
Vol 103 (8) ◽  
pp. 753-756 ◽  
Author(s):  
Claire Edmondson ◽  
Christopher Grime ◽  
Ammani Prasad ◽  
Jacqui Cowlard ◽  
Chinedu E C Nwokoro ◽  
...  

Newborn babies positively screened for cystic fibrosis (CF) (high serum immunoreactive trypsin (IRT) with DNA analysis) are referred for a diagnostic sweat test, which may be normal (sweat chloride <30 mmol/L). Unless two gene mutations are identified during Newborn screening (NBS), the babies are discharged from follow-up. We wished to check that none had subsequently developed symptoms suggestive of CF. We retrospectively reviewed patient notes and contacted general practitioners of all babies with a negative sweat test, conducted in one of the four paediatric specialist CF centres in London, over the first 6 years of screening in South East England.Of 511 babies referred, 95 (19%) had a normal sweat test. Five (5%) had CF diagnosed genetically, two of them on extended genome sequencing after clinical suspicion. Eleven (12%) were designated as CF screen positive inconclusive diagnosis (CFSPID); one of the five CF children was originally designated as CFSPID. Seventy-nine (83%) were assumed to be false-positive cases and discharged; follow-up data were available for 51/79 (65%); 32/51 (63%) had no health issues, 19/51 (37%) had other significant non-CF pathology.These results are reassuring in that within the limitations of those lost to follow-up, CF symptoms have not emerged in the discharged children. The high non-CF morbidity in these children may relate to known causes of high IRT at birth. Clinicians need to be aware that a child can have CF despite a normal sweat test following NBS, and if symptoms suggest the diagnosis, further testing, including extended genome sequencing, is required.


2021 ◽  
Vol 24 (1) ◽  
pp. 41-46
Author(s):  
S Fustik ◽  
V Anastasovska ◽  
D Plaseska-Karanfilska ◽  
A Stamatova ◽  
L Spirevska ◽  
...  

Abstract There is a widely accepted consensus on the benefits of newborn screening (NBS) for cystic fibrosis (CF) in terms of reduced disease severity, improved quality of life, lower treatment burden, and reduced costs. More and more countries in the world are introducing NBS for CF as a national preventive health program. Newborn screening for CF was introduced in the Republic of North Macedonia (RNM) in April, 2019, after a pilot study of 6 months in 2018. A two-step immunoreactive trysinogen (IRT-IRT) algorithm is performed, and then a sweat test for confirmation/exclusion of the CF diagnosis when the IRT values were both over the cutoff (70.0 and 45.0 ng/mL, respectively). In cases with confirmed diagnosis of CF (a sweat chloride concentration >60.0 mmol/L) or with intermediate sweat test results (a sweat chloride concentration of between 30.0 and 59.0 mmol/L), CF transmembrane conductance regulator (CFTR) mutation analysis is performed. By the end of 2020, over a period of 27 months, including the pilot study period, a total number of 43,139 newborns were screened for CF. Seventeen (0.039%) newborns were diagnosed with CF. In all newly discovered CF cases by screening, the diagnosis was confirmed by determination of the CFTR mutations. The most common CFTR mutation, F508del, was found with an overall incidence of 70.6%. Other more frequent mutations were G542X (11.8%) and N1303K (5.9%). Four mutations were found in one CFTR allele each: G1349D, G126D, 457TAT>G and CFTRdupexon22, with the last one being newly discovered with unknown consequences. An incredibly large difference was found in the incidence of the disease between the Macedonian and Albanian neonatal population, with almost four time higher prevalence among Albanians (1:4530 vs. 1:1284).


Author(s):  
Šubat-Dežulović Mirna ◽  
Pelčić Gordana ◽  
Valković Ana ◽  
Flajšman-Raspor Sanja ◽  
Pelčić Goran ◽  
...  

Cystic Fibrosis (CF) is a common inherited disease with reported mean prevalence of 0.737/10,000 in 27 EU countries (Farrell J Cyst Fibros. 2008). Still, many EU countries have not implemented CF in the Newborn Screening (NBS) programme, including our country. We report the case of a 7-month-old boy whose presenting signs of CF were life-threatening neurological symptoms caused by severe metabolic alkalosis and hypoelectrolytemia. By presenting this case, we argue hoping to persuade the authorities in any country that the available newborn screening for CF is the cost benefit procedure in preventing life treating consequences with the obvious impact on the long-term prognosis of this chronic disease.


PEDIATRICS ◽  
1998 ◽  
Vol 102 (Supplement_1) ◽  
pp. 230-231
Author(s):  
Victor Chernick

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 &gt;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.


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