Diagnostic Sweat Testing: The Cystic Fibrosis Foundation Guidelines

Newborn Screening for Cystic Fibrosis in California

“…SCTs are performed by CFF-accredited laboratories according to current standards 15 and guidelines. 16 Parents are encouraged to provide salt supplementation and hydration to the infant before testing. Follow-up is conducted with the use of guidelines developed by CFCs and GDSP.…”

“…METHODS: From July 16,2007, to June 30, 2012, a total of 2 573 293 newborns were screened for CF by using a 3-step model: (1) measuring immunoreactive trypsinogen in all dried blood spot specimens; (2) testing 28 to 40 selected cystic fibrosis transmembrane conductance regulator (CFTR) mutations in specimens with immunoreactive trypsinogen values $62 ng/mL (top 1.6%); and (3) performing DNA sequencing on specimens found to have only 1 mutation in step 2. Infants with $2 mutations/variants were referred to CF care centers for diagnostic evaluation and follow-up.…”

Detection of a large heterozygous deletion and a splicing defect in the CFTR transcripts from nasal swab of a Japanese case of cystic fibrosis

“…The pilocarpine iontophoresis is the standard method to stimulate sweat-gland secretion in the forearm or back. However, it requires experienced personnel and a quality-controlled laboratory, 15 which is hardly expected in Japan. Accordingly, detection of disease-causing mutations of CFTR is often necessary for the definite diagnosis of CF in Japan.…”

Sweat testing: can the conductivity analysis take the place of the classic Gibson and Cooke technique?

“…Contudo, os sujeitos com FC examinados tinham mais de 18 meses (a idade dos sujeitos sem FC não foi fornecida) e o tempo de coleta após estimulação durou de 30 a 60 minutos. Sabe-se que um tempo de coleta prolongado pode favorecer a taxa de sucesso, mas também pode alterar a concentração de eletrólitos: por essa razão, o tempo padrão recomendado é de 30 minutos 2,11,12 . Outros estudos sugerem que a taxa de falha com a coleta feita com o Macroduct ® é mais alta, especialmente nos primeiros meses de vida, e que a taxa de sucesso é mais alta com o sistema clássico 6,7 .…”