Children with cystic fibrosis can acquire nonmucoid Pseudomonas aeruginosa and mucoid P. aeruginosa very early in life, and the prevalence of the mucoid form increases significantly as children age, according to results from a long-term study.
“Early prevention and detection of nonmucoid P. aeruginosa and mucoid P. aeruginosa is critical because of early acquisition and prevalence,” said Zhanhai Li, Ph.D., of the University of Wisconsin, Madison, and associates. “There is a window of opportunity for suppression and possible eradication of initial nonmucoid P. aeruginosa.”
For the study, which is called the first of its kind, the investigators prospectively evaluated 56 cystic fibrosis (CF) patients at two CF centers between April 15, 1985, and April 15, 2004 (JAMA 2005;293:581-8). Diagnoses were made through the Wisconsin CF Neonatal Screening Project. The children who participated in the study were seen every 6 weeks for the first year of life, then every 3 months for up to 16 years.
Of the 56 patients, 16 (29%) acquired nonmucoid P. aeruginosa in the first 6 months of life.
Among those who reached 16, nearly all (92%) developed mucoid P. aeruginosa. It took a median of 1 year for children to develop the nonmucoid form, compared with a median of 13 years for children to develop the mucoid form.
“Initial nonmucoid P. aeruginosa can possibly be eradicated by aggressive anti-P. aeruginosa treatment, but once mucoid P. aeruginosa is established, eradication seems impossible, and a life-threatening situation develops,” they said.
The investigators observed that relatively low antibody titers point to nonmucoid P. aeruginosa and high titers to the mucoid form.
“We also demonstrated that dramatic cough score and chest radiograph changes were associated with progressive lung infections that led to impaired pulmonary function,” Dr. Li and associates said. “Therefore, cough scores and chest radiographs may also signal nonmucoid P. aeruginosa and, especially, P. aeruginosa stages and potentially guide therapeutic decisions.”
The investigators said that the small sample of patients is a limitation of the study and that larger studies will be needed to confirm the findings.
The National Institutes of Health and the Cystic Fibrosis Foundation supported the study.