Source: Laryngoscope  |  Posted 9 years ago

Neonatal screening for three antibodies allows early detection of the bacteria that causes []Pseudomonas aeruginosa[] pulmonary infection in children with cystic fibrosis (CF).

Testing for immunoglobins IgG, IgA and IgM allows P aeruginosa detection six to 12 months before the organism is identified in cultures.

Researchers from the University of Wisconsin in Madison and the Medical College of Wisconsin in Milwaukee, United States, say such testing could facilitate diagnosis and treatment of children with CF: "Early diagnosis through neonatal screening provides an opportunity for a transformation in treatment strategy.

"Instead of hospitalisations and medical interventions for sick patients who experience delayed diagnosis, screening allows pre-symptomatic identification of most patients with CF and the potential for prospective evaluation and preventive care."

They explain that the CF lung is free of pathology at birth. "Early diagnosis coupled with careful follow-up of the respiratory symptoms (especially cough), infection status and chest radiographs could provide better outcomes."

Researchers also recommend that longitudinal P aeruginosa serology become part of the children's respiratory care follow-up, especially the use of exotoxin A titres.

They evaluated the longitudinal relationship between the production of antibody response against P aeruginosa and clinical factors associated with infections in 68 CF patients who had been diagnosed early.

Serum samples and oropharyngeal cultures were obtained from participants at six-month intervals from April 1995 to April 2000 or for up to 180 months, depending on the enrolment date. Participants had been diagnosed through the Wisconsin CF Neonatal Screening Project.

The median time to an antibody titre of at least 1:256 was 17.8 months for cell lysates, 24.2 months for exotoxin A and 70.9 months for elastase.

The rise of anti-cell lysates titres to 1:256 or more occurred a mean of 11.9 months before the isolation of P aeruginosa for all cultures. For anti-exotoxin A titres, the mean time was 5.6 months.

"Treatment with long-term, non-Pseudomonas oral antibiotics and integration of CF infants with older, chronically infected patients were associated with a significantly increased risk of P aeruginosa pulmonary infection," the researchers add.