Improving the Rate of Sufficient Sweat Collected in Infants Referred for Sweat Testing in Michigan

Abdulhamid, Ibrahim; Kleyn, Mary; Langbo, Carrie; Gregoire-Bottex, Myrtha; Schuen, John; Shanmugasundaram, Krithika; Nasr, Samya Z.

doi:10.1177/2333794x14553625

Cited by 5 publications

(13 citation statements)

References 14 publications

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“…A coulometric chloridometer enables quantitative analysis of the collected samples. In practice, the collection of sufficient volumes of sweat for analysis can be challenging-especially in infants (20)(21)(22)(23)(24)(25). Clinical and Laboratory Standards Institute (CLSI) guidelines specify the collection of at least 15 l of sweat within a 30-min time period for accurate analysis using the MSCS (6).…”

Section: Introductionmentioning

confidence: 99%

Soft, skin-interfaced sweat stickers for cystic fibrosis diagnosis and management

et al. 2021

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The concentration of chloride in sweat remains the most robust biomarker for confirmatory diagnosis of cystic fibrosis (CF), a common life-shortening genetic disorder. Early diagnosis via quantitative assessment of sweat chloride allows prompt initiation of care and is critically important to extend life expectancy and improve quality of life. The collection and analysis of sweat using conventional wrist-strapped devices and iontophoresis can be cumbersome, particularly for infants with fragile skin, who often have insufficient sweat production. Here, we introduce a soft, epidermal microfluidic device (“sweat sticker”) designed for the simple and rapid collection and analysis of sweat. Intimate, conformal coupling with the skin supports nearly perfect efficiency in sweat collection without leakage. Real-time image analysis of chloride reagents allows for quantitative assessment of chloride concentrations using a smartphone camera, without requiring extraction of sweat or external analysis. Clinical validation studies involving patients with CF and healthy subjects, across a spectrum of age groups, support clinical equivalence compared to existing device platforms in terms of accuracy and demonstrate meaningful reductions in rates of leakage. The wearable microfluidic technologies and smartphone-based analytics reported here establish the foundation for diagnosis of CF outside of clinical settings.

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Section: Introductionmentioning

confidence: 99%

Soft, skin-interfaced sweat stickers for cystic fibrosis diagnosis and management

et al. 2021

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“…Additionally, sweat electrolyte analyses by di Sant'Agnese and colleagues presumed no differences in sweat glands based on racial background [32]. Much like Abdulhamid et al, which addressed ST QNS rates across CF Centers in Michigan [25], in our QI population, there was no difference in time to successful ST completion between Caucasian and African American or other ethnicities unlike other prior reports [13,28].…”

Section: Discussionmentioning

confidence: 67%

“…Current CFF guidelines suggest ST may be completed within the first 2 weeks of life (but greater than 24 h of age) in infants with BW >2.0 kg [ 16 ]. Despite these suggestions, many States have documented QNS rates >10% despite guidelines provided by the CFF [ 25 , 26 , 27 ]. Over 2 years, the average ST QNS rate at our CF Center was 22% but fluctuated depending on interventions and decreased to an average of 14% in the last 6 months of the study when addressing infant and laboratory factors.…”

Section: Discussionmentioning

confidence: 99%

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

Shenoy

Spyropoulos

Peeke

et al. 2020

IJNS

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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.

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“…Therefore, the Cystic Fibrosis Foundation (CFF) recommended that the laboratory QNS rate should be measured at certain intervals and minimized. Based on the recommendation of CFF, the standard is that QNS rates should not exceed 10% for infants aged 3 months or less and 5% for patients older than 3 months [2,12]. However, there is no recommendation how to reduce the rate of inadequate sweat volume in the CFF guidelines.…”

Section: Discussionmentioning

confidence: 99%

“…The minimal acceptable sweat volume for analysis is 75 mg for the Gibson-Cooke procedure and 15 µL for the Macroduct system [7,11]. Lower weights or volumes of sweat specimens cannot be analyzed and are labeled as quantity not sufficient (QNS) [2]. The aim of this study was to evaluate the data of 1 sweat test laboratory to determine the rate of insufficient sweat volume and the eventual implementation of corrective preventive actions.…”

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confidence: 99%

The most common preanalytic problem of sweat testing: Insufficient sweat volume

Ozgenc¹

2020

Int J Med Biochem

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The most common preanalytic problem of sweat testing: Insufficient sweat volume C ystic fibrosis (CF) is a fatal disease, an inherited autosomal recessive disorder resulting from mutations in the CF transmembrane conductance regulator gene, located in the long arm of chromosome 7 [1]. The prevalence is about 1 in 3500 live births [2]. According to the limited number of studies, the incidence of CF is about 1/3000 in Turkey. However, the rate is thought to be higher due to the frequency of consanguineous marriage [3]. In studies, early diagnosis and treatment has led to improved nutritional status and lung function, prolonging the life span by reducing hospitalizations and morbidity [1, 4]. Therefore, CF has been part of newborn screening programs in some parts of the world for many years [5]. In Turkey, all newborns have been screened for immunoreactive trypsinogen from a dried blood spot since January 1, 2015 and positive cases are referred for a sweat test. The sweat test is the gold standard method for the diagnosis of CF based on the quantitative determination of electrolytes in the sweat sample [6]. The test consists of 3 steps: Stimulation of sweat glands by pilocarpine iontophoresis, sweat collection, and analysis. The primary sweat collection methods Objectives: A sweat test is the gold standard method for the diagnosis of cystic fibrosis (CF). The most important preanalytical error for sweat testing is insufficient sweat volume. The aim of this study was to determine rates of insufficient sweat volume and evaluate the relationship of sweat volume with demographic characteristics of patients, as well as the implementation of corrective preventive actions. Methods: This study was performed retrospectively in the sweat test laboratory of the Cerrahpasa Faculty of Medicine of Istanbul University-Cerrahpasa. A total of 545 specimens that were referred to the laboratory between May and December 2016 were evaluated. Sweating was stimulated with pilocarpine iontophoresis, and the Macroduct Coil System (Wescor, Inc., Logan, UT, USA) was used as the sweat collection system. Sweat volume <15 μL was evaluated as quantity not sufficient (QNS). A chi-square test was used for statistical analysis; p<0.05 was considered significant. Results: The QNS rate in the study laboratory was 13.8% for infants ≤3 months of age and 6% for patients aged >3 months (p=0.019). There was no significant difference in the QNS ratios according to gender (p=1.000) or the season when the test was applied (p=0.181). Conclusion: The determination of QNS rates is a crucial step in the standardization of the preanalytical conditions of a sweat test. In this study, the QNS rate was above that recommended by the Cystic Fibrosis Foundation (<10% for infants ≤3 months of age, <5% for patients >3 months). High QNS ratios may be due to the inadequacy of optimization of pre-test preparation. Laboratory staff and parents should be well informed about preanalytical factors before a sweat analysis is performed in order to reduce the QNS rate.

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Improving the Rate of Sufficient Sweat Collected in Infants Referred for Sweat Testing in Michigan

Cited by 5 publications

References 14 publications

Soft, skin-interfaced sweat stickers for cystic fibrosis diagnosis and management

Soft, skin-interfaced sweat stickers for cystic fibrosis diagnosis and management

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

The most common preanalytic problem of sweat testing: Insufficient sweat volume

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