The role of serum Pseudomonas aeruginosa antibodies in the diagnosis and follow-up of cystic fibrosis.

In cystic fibrosis (CF), if Pseudomonas aeruginosa (Pa) infection is not diagnosed and treated early, chronic colonization occurs, which causes rapid decline in pulmonary functions. The aim of this study was to evaluate Pa antibodies, compare them with Pa cultures and determine their role in early diagnosis and follow-up. Ninety CF patients were included; they were divided into chronic, intermittent, negative, and mucoid groups. They were evaluated every 3-6 months. In each visit, pulmonary function tests and sputum cultures were obtained, and Pa antibodies exotoxin A (ExoA), elastase (ELA) and alkaline protease (AP) were determined in the serum by enzyme-linked immunosorbent assay (ELISA). The most specific test that discriminated chronic colonized patients from noncolonized patients was Pa culture, and the presence of at least one antibody had the highest sensitivity. AP had the highest specificity, and ELA had the highest sensitivity. All antibodies were highest in the mucoid group. ELA was highest in chronic and lowest in the negative group. The presence of antibodies was much higher than positive Pa cultures in patients younger than five years of age. A negative correlation between forced expiratory volume in 1 second (FEV1) and AP was determined only in the mucoid group. In the two-year follow-up, antibody presence did not show a regular pattern. In CF, Pa antibodies can be early markers for diagnosis, especially in young children who cannot expectorate, but they should only be used together with sputum cultures for long-term follow-up and treatment.

Sweat conductivity test: can it replace chloride titration for cystic fibrosis diagnosis?

Although sweat conductivity values are well matched with chloride concentrations for cystic fibrosis (CF) diagnosis, sweat conductivity is not accepted as a definitive diagnostic tool but only a screening method. The aim of this study was to compare the sweat chloride measurements and sweat conductivity values of our patients, and to determine cut-off values of conductivity for making or excluding a CF diagnosis. Fifty-nine CF patients, 10 patients with elevated sweat tests and 69 non-CF patients were included in the study. The mean conductivity values were 123 (64-157) mmol/L, 75.1 (60-93) mmol/L and 39 (18-83) mmol/L in the CF, elevated sweat test and control groups, respectively. The mean chloride concentration values were 107.5 (35-166) mEq/L, 48 (42-76) mEq/L and 25 (11-39) mEq/L in the CF, elevated sweat test and control groups, respectively. Spearman correlation test determined a strong correlation between conductivity and chloride concentration values (r=88%, p<0.001) in all subjects. According to the receiver operating characteristic (ROC) curve graph, the best conductivity cut-off value to make the CF diagnosis was found to be 90 mmol/L and to exclude the CF diagnosis was 70 mmol/L. We suggest that the conductivity measurement is as reliable as quantitative sweat chloride analysis to diagnose or exclude CF, and it can be used as a diagnostic test in addition to screening.

Long-term clarithromycin in cystic fibrosis: effects on inflammatory markers in BAL and clinical status.

Macrolides have antiinflammatory effects that are potentially useful in cystic fibrosis (CF). In this placebo-controlled, randomized, double-blind crossover study, 18 CF patients were randomized to receive either clarithromycin (CM) (Group 1) or placebo (Group 2) for three months. After 15 days, the treatments were crossed over. Bronchoalveolar lavage (BAL) was obtained in the beginning and at the end of each treatment period. There was no significant difference in median cell counts and median cytokine levels at baseline, after CM use and after placebo use between the two groups. In Group 2, the median neutrophil elastase (NE) level decreased with CM. Patients had less acute pulmonary exacerbations and median clinical score decreased with CM in both groups. Median z-scores for weight increased with CM in Group 2. We could not demonstrate a fall in proinflammatory cytokines in BAL; however, some improvement in clinical status could be shown with three-month CM.

Environmental tobacco smoke exposure and respiratory morbidity in children.

Environmental tobacco smoke (ETS) contains carcinogenic and toxic agents. Smoking might have a more serious effect on children than adults. We aimed to examine the effects of passive smoking on pulmonary function and respiratory health in children and to assess the concordance between parental self-reported smoking habits and urinary cotinine levels in their children. This cross-sectional study was conducted in the winter with the participation of 131 children (9-12 yr old). The procedure for each subject consisted of administration of a questionnaire to the parents, and collection of a urine sample and measurement of lung function in each child. Cotinine level excreted into urine was analyzed with respect to parental self-reported smoking behavior. Working mothers and mothers with higher level of education tended to smoke more at home (p values, respectively, .002 and .005). There was a statistical difference between the urinary cotinine levels of children when divided into two groups according to their fathers' smoking behavior at home (p = .0001). No statistically significant difference was determined in the mean episodes of respiratory infections treated during the last 12 mo among the groups formed according to daily number of cigarettes smoked by the parents at home (1: not exposed; 2: < 5 cigarettes; 3: 5-10 cigarettes; 4: > 10 cigarettes), or among the groups formed according to urinary cotinine levels (1: < 10 ng/ml; 2: > or =10 ng/ml). No significant difference was demonstrated in any of the respiratory function parameters investigated between the groups considered. The reliability of the declarations of the parents in the estimation of ETS exposure of children was low. Children are unable to remove themselves from ETS exposure. It is better to reduce the percentage of parents who smoke rather than to isolate smokers or increase ventilation.