Raised immunoreactive trypsin but normal sweat test

2018 ◽  
Vol 54 (12) ◽  
pp. 1402-1402
Author(s):  
David Isaacs
1997 ◽  
Vol 4 (1) ◽  
pp. 23-28 ◽  
Author(s):  
R J Pollitt ◽  
A Dalton ◽  
S Evans ◽  
H N Hughes ◽  
D Curtis

Objectives— To assess neonatal screening for cystic fibrosis using immunoreactive trypsin, either alone or in conjunction with DNA analysis for the AF508 mutation. A novel three-stage screening protocol was compared with the previously introduced two-stage immunoreactive trypsin-DNA protocol. Design— (a) Collection of data from a 41/2 year period (phase 1) of two-stage immunoreactive trypsin screening. The initial dried blood samples were obtained at 6 days of age and repeat samples at 27 days of age from babies with results above the 99.5th centile. Babies with persistent hypertrypsinaemia were referred for a diagnostic sweat test. (b) Retrospective DNA analysis: Patients with cystic fibrosis diagnosed in phase 1 were genotyped and most samples from babies with increased initial immunoreactive trypsin but normal results in the second sample were analysed for the δF508 mutation, (c) Phase 2, a prospective study of a three-stage neonatal screening protocol, in which only babies heterozygous for the δF508 cystic fibrosis mutation progressed to the second immunoreactive trypsin test. Setting— The Trent neonatal screening programme. Subjects— 437 859 babies born between August 1989 and March 1996. Main outcome measures— Proportions of unaffected babies requiring a second blood sample or a sweat test. Overall sensitivity for the detection of cystic fibrosis. Results— The two-stage screen failed to identify six out of 94 cases of cystic fibrosis (without meconium ileus). The introduction of the DNA analysis step would have resulted in one additional case being missed. With the three-stage screen there was a 92% reduction in babies requiring a second blood sample and an 80% reduction in negative sweat tests, results close to the predictions of the retrospective study. Conclusions— The three-stage screening protocol is a marked improvement on the two-stage immunoreactive trypsin strategy and on the two-stage immunoreactive trypsin-DNA strategy recently introduced in some other screening programmes.


Author(s):  
J.D. Shelburne ◽  
G.M. Roomans

Proper preparative procedures are a prerequisite for the validity of the results of x-ray microanalysis of biological tissue. Clinical applications of x-ray microanalysis are often concerned with diagnostic problems and the results may have profound practical significance for the patient. From this point of view it is especially important that specimen preparation for clinical applications is carried out correctly.Some clinical problems require very little tissue preparation. Hair, nails, and kidney and gallbladder stones may be examined and analyzed after carbon coating. High levels of zinc or copper in hair may be indicative of dermatological or systemic diseases. Nail clippings may be analyzed (as an alternative to the more conventional sweat test) to confirm a diagnosis of cystic fibrosis. X-ray microanalysis in combination with scanning electron microscopy has been shown to be the most reliable method for the identification of the components of kidney or gallbladder stones.A quantitatively very important clinical application of x-ray microanalysis is the identification and quantification of asbestos and other exogenous particles in lung.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Friederike Wilbert ◽  
Sarah C. Grünert ◽  
Andrea Heinzmann ◽  
Sebastian F. N. Bode

Abstract Background Childhood hypoglycemia in combination with hepatomegaly is suspicious for inborn errors of metabolism. Cystic fibrosis typically presents with failure to thrive, pulmonary and gastrointestinal symptoms. Hepatic involvement and hypoglycemia can occur in a significant number of patients, although hepatomegaly is uncommon. Case presentation A 28 months old boy was presented with recurrent upper airways infections, progressive lethargy and weight loss. Clinically hepatomegaly was the main presenting feature and hypoglycemia (minimum 1.4 mmol/l) was noted as were elevated transaminases. The patient did not produce enough sweat to analyze it. Infectious causes for hepatitis were excluded and a broad metabolic work-up initiated. A therapy with starch was initiated to control hypoglycemia. In further course loose stools were reported and pancreatic elastase was found to be reduced. A further sweat test yielded pathological chloride concentration and genetic testing confirmed the diagnosis of cystic fibrosis. Conclusions Cystic fibrosis is a systemic disease and less common presentations need to be considered. Even in the age of CF-newborn screening in many countries CF needs to be ruled out in typical and atypical clinical presentations and diagnostics need to be repeated if inconclusive.


Thorax ◽  
1981 ◽  
Vol 36 (1) ◽  
pp. 60-62 ◽  
Author(s):  
P Dandona ◽  
M Hodson ◽  
J Bell ◽  
L Ramdial ◽  
I Beldon ◽  
...  

BMJ ◽  
1982 ◽  
Vol 284 (6310) ◽  
pp. 199-200
Author(s):  
B. M Frier

1981 ◽  
Vol 113 (2) ◽  
pp. 111-121 ◽  
Author(s):  
Jeanette R. Crossley ◽  
Patricia A. Smith ◽  
Brian W. Edgar ◽  
Peter D. Gluckman ◽  
Robert B. Elliott

2009 ◽  
Vol 55 (3) ◽  
pp. 454-462 ◽  
Author(s):  
Allan J Barnes ◽  
Bruno S De Martinis ◽  
David A Gorelick ◽  
Robert S Goodwin ◽  
Erin A Kolbrich ◽  
...  

Abstract Background: Understanding the excretion of 3,4-methylenedioxymethamphetamine (MDMA) and metabolites in sweat is vital for interpretation of sweat tests in drug treatment, criminal justice, and workplace programs. Methods: Placebo, low (1.0 mg/kg), and high (1.6 mg/kg) doses of oral MDMA were given double-blind in random order to healthy volunteers (n = 15) with histories of MDMA use. Participants resided on the closed clinical research unit for up to 7 days after each dose. Volunteers wore PharmChek® sweat patches (n = 640) before, during, and after controlled dosing. Patches were analyzed by solid phase extraction and GC-MS for MDMA, methylenedioxyamphetamine (MDA), 4-hydroxy-3-methoxyamphetamine (HMA), and 4-hydroxy-3-methoxymethamphetamine (HMMA). Limits of quantification (LOQ) were 2.5 ng/patch for MDMA and 5 ng/patch for HMA, HMMA, and MDA. Results: MDMA was the primary analyte detected in 382 patches (59.7%), with concentrations up to 3007 ng/patch. MDA was detected in 188 patches (29.4%) at <172 ng/patch, whereas no HMMA or HMA was detected; 224 patches (35.0%) and 60 patches (9.4%) were positive for MDMA and MDA, respectively, at the 25-ng/patch threshold proposed by the Substance Abuse and Mental Health Services Administration. Conclusions: Sweat testing was shown to be an effective and reliable method for monitoring MDMA use in this controlled MDMA administration study. However, variability in sweat excretion suggests that results should be interpreted qualitatively rather than quantitatively. These data provide a scientific database for interpretation of MDMA sweat test results.


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