[Iron deficiency and Pseudomonas aeruginosa colonization in cystic fibrosis]

Abstract

The incidence of iron deficiency and its relationship with the concentration or iron in sputum and the number of Pseudomonas aeruginosa (PA) colonies was studied in an unselected group of 53 cystic fibrosis (CF) patients with an age range of 3 months to 21 years. Parameters used to assess the iron status included serum iron, the % saturation of transferrin (n = 53). The number of subjects with depletion of iron stores was estimated by levels of ferritin (n = 50). The concentration of iron and of PA was measured in a subgroup (n = 24) and compared to a control group (n = 8) with pulmonary infections of varying etiology. A close correlation was found between serum iron and the % saturation of transferrin (r = 0.952; p less than 0.001). Between 22.6 to 28.3% of patients were found to be iron deficient. An abnormally low ferritin (less than 12 ng/ml) was noted in 28% of cases but no correlation could be established between changes of serum iron and ferritin levels as a function of the degree of infection and/or of inflammation. In 62% of cases (n = 15) the concentration of iron in sputum was found to be within the range of control values (12-27 mumols/l). In 38% of cases (n = 9), ferritin values were above 27 mumols/l. No correlation was found between the concentration of iron and the number of PA colonies in sputum. We can therefore conclude the following: 1) iron deficiency is more common in CF than previously reported; 2) ferritin levels constitute a poor index of iron deficiency; 3) colonisation with PA is not associated with iron content of bronchial secretions.