BACKGROUND: Cystic fibrosis is a chronic progressive autosomal recessive disorder caused by the CFTR gene mutations. It is quite common in Caucasians, but very rare in Asians. Sweat chloride test is known to be a screening test for the cystic fibrosis due to the fact that electrolyte levels in sweat are elevated in patients. In this study, sweat chloride levels in Korean population were measured and analyzed by using standardized pilocarpine iontophoresis sweat chloride test. METHODS: The sweat chloride test was performed in 47 patients referred to Yondong Severance Hospital from August, 2001 to April, 2007 and 41 healthy volunteers. The sweat chloride tests were conducted according to the CLSI C34-A2 guideline using pilocarpine iontophoresis method, and the chloride concentrations in sweat were measured by mercurimetric titration. RESULTS: Four patients showed sweat chloride concentrations higher than 60 mmol/L. Reference interval was calculated as 1.4-44.5 mmol/L by analysis of the results of healthy volunteers (n=41). Four patients who exhibited high sweat chloride levels, had characteristic clinical features of cystic fibrosis and their diagnoses were confirmed either by repeated sweat chloride test or genetic analysis. CONCLUSIONS: Standardized sweat chloride test can be utilized as a useful diagnostic tool for cystic fibrosis in Koreans. In cases of sweat chloride levels higher than 40 mmol/L, the test should be repeated for the possible diagnosis of cystic fibrosis. All the confirmed Korean cases of cystic fibrosis showed sweat chloride level above 60 mmol/L.
Adolescent ; Adult ; Child ; Child, Preschool ; Chlorides/*analysis/*standards ; Cystic Fibrosis/*diagnosis/genetics ; Female ; Humans ; Infant ; Iontophoresis/methods ; Korea ; Male ; Middle Aged ; Pilocarpine/chemistry ; Sequence Analysis, DNA ; Sweat/chemistry/*secretion

BACKGROUND: Point-of-care (POC) tests are used increasingly due to fast results and simple test procedures, which enables rapid diagnosis and therapeutic monitoring. We evaluated the performance of the Piccolo xpress Chemistry Analyzer (Abaxis, USA) a POC chemistry analyzer. METHODS: Fourteen analytes, Na+, K+, Cl-, Ca2+, total carbon dioxide, AST, ALT, total bilirubin, alkaline phosphatase, blood urea nitrogen, creatinine, albumin, total protein, and glucose; were measured simultaneously with a 100 microliter of whole blood sample using a Comprehensive Metabolic Reagent disk. Within-run and total precision and linearity were evaluated according to CLSI EP15-A and EP6-A guidelines, respectively. Comparison with a central laboratory chemistry analyzer was performed using 144 patient samples. RESULTS: The coefficients of variations of within-run and total precision were all within 5% for three levels except for total carbon dioxide, ALT, alkaline phosphatase, total bilirubin, and creatinine in low level, and creatinine in middle level. The results of 14 analytes were linear within a commonly encountered range in clinical samples (r2> or =0.98). More than 10% of samples in Na+, AST, ALT, glucose, BUN did not satisfy CLIA analytical quality requirement. CONCLUSIONS: The Piccolo xpress Chemistry Analyzer can analyze multiple analytes with a minimal amount of whole blood in a short time. It showed an acceptable performance for precision, linearity and comparison with central laboratory analyzer. It can be useful as a screening tests modality in mobile clinics, ambulances, and field clinics for military use, and for pediatric patients from whom enough sample volume is difficult to obtain.
Alanine Transaminase/blood ; Alkaline Phosphatase/blood ; Aspartate Aminotransferases/blood ; Bilirubin/blood ; Blood Chemical Analysis/*instrumentation/methods/*standards ; Blood Glucose/analysis ; Calcium/blood ; Carbon Dioxide/blood ; Chlorides/blood ; Creatinine/blood ; Humans ; *Point-of-Care Systems ; Potassium/blood ; Quality Control ; Reproducibility of Results ; Serum Albumin/analysis ; Sodium/blood