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In an attempt to ascertain a relationship between genotype and phenotype, we studied the pulmonary and nutritional status of 123 cystic fibrosis patients with known genotype at an age of 8.5-10 years. Patients represent a cohort as they are almost all those born and diagnosed in a given area and period. They were followed at a single centre using uniform diagnostic and treatment protocols. Pulmonary and nutritional status of homozygous delta 508 patients did not differ from that of compound heterozygotes or of patients with other unspecified genotypes. Pulmonary manifestations varied widely in all genotype groups. With the given number of patients, a slightly higher mortality of delta F508 homozygotes could have been coincidental. We conclude that up to the age of 8.5-10 years the severity of pulmonary lesions and nutritional deficiencies is not related to the delta F508 mutation.

The clinical course of nine cystic fibrosis patients homozygous for the CF gene nonsense mutation R1162X was investigated. Since this mutation should lead to an interruption in the synthesis of the cystic fibrosis transmembrane regulator (CFTR) protein, a severe clinical course was expected. All patients showed pancreatic insufficiency, while the course of the lung disease was mild to moderate. These results suggest that this form of truncated CFTR protein, still containing the regulatory region, the first ATP binding domain, and both transmembrane domains, could be partially working in the lung tissues.Among them, the RI 162X nonsense mutation"5 is relatively frequent in north-eastern Italy'4; therefore patients carrying this mutation on both their genes are more easily found. The R1 162X mutation is characterised by the substitution of the amino acid arginine in position 1162 of CFTR with a UGA termination codon.'5Here we report our results on the correlation between the Rl 162X mutation and the clinical manifestations of cystic fibrosis, including meconium ileus, pancreatic function, lung involvement, growth rate, etc, as shown by the nine patients identified so far in our population who are homozygotes for the mutation. The possible pathophysiological role of the Rl 162X mutation is discussed.

An objective approach for monitoring the treatment of acute pulmonary exacerbation in cystic fibrosis was evaluated. Eleven biochemical markers of inflammation (erythrocyte sedimentation rate, neutrophil count, C-reactive protein, alpha-1 antitrypsin, haptoglobin, ceruloplasmin, fibronectin, alpha-1 glycoprotein, alpha-2 macroglobulin, C3, granulocyte elastase and anti-Pseudomonas IgG) were measured in blood serum and plasma from 46 cystic fibrosis patients with chronic Pseudomonas aeruginosa colonization before and after treatment. The overall outcome in each patient was evaluated by means of a pondered sum of clinical, chest X-ray and lung function scores. Biochemical markers were related to the overall clinical improvement: haptoglobin, ceruloplasmin, fibronectin and alpha-1 glycoprotein showed a good sensitivity (64-70%), specificity (60-70%) and positive predictive value (86-89%). Granulocyte elastase showed a similar sensitivity (67%) and positive predictive value (85%) but a lower specificity (33%). The negative predictive value was generally poor (32-39%). Our data suggest that the combined measurement of some markers of inflammation and of conventional clinical parameters, may help in evaluating the efficacy of anti-infective treatment in cystic fibrosis.

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