[Neonatal cystic fibrosis screening program in the state of Paraná: evaluation 30 months after implementation]

To present and analyze the results of the National Neonatal Cystic Fibrosis Screening Program in Paraná, 30 months after its implementation.

This is a descriptive study, with an analysis of the data from the screening of around 98% of all neonates in the period from September 2001 to April 2004, undertaken at the Neonatal Screening Program laboratory of the Fundação Ecumênica de Proteção ao Excepcional do Paraná. Blood samples for the Guthrie test were collected on hospital discharge, ideally between the second and sixth days postpartum, and filter papers were sent for immunoreactive trypsin assay by the immunofluorometric method. Children whose immunoreactive trypsin assay results were > or = 70 ng/ml for two distinct samples during the first 30 days of life, were referred for sweat conductivity testing by the Wescor method. In cases when the result was greater than 50 mMol/l quantitative chlorine and/or sodium in sweat was assayed (iontophoresis with pilocarpine).

From a total of 456,982 tests, 4,028 (0.9%) children presented a first immunoreactive trypsin assay above the cutoff point set. Four hundred and seventy-eight of these (12.5%) also had a second blood sample assayed with immunoreactive trypsin above 70 ng/ml and 56 (11.7%) of these were referred to specialized clinics after their sweat conductivity test results were above 50 mMol/l and 48 (0.01% of the total number of children screened) had a diagnosis of cystic fibrosis confirmed. The incidence for the state of Paraná was 1:9,520, although some children have not yet been fully investigated.

Neonatal screening for cystic fibrosis in the State of Paraná, in accordance with Health Ministry directives, was a pioneering initiative for Brazil. Many patients were diagnosed early, even asymptomatic ones, which is a challenge to improving prognosis with this fatal disease.