Non-classic cystic fibrosis associated with D1152H CFTR mutation

BACKGROUND

Limited knowledge exists on phenotypes associated with the D1152H cystic fibrosis transmembrane conductance regulator (CFTR) mutation.

METHODS

Subjects with a D1152H allele in trans with another CFTR mutation were identified using the French Cystic Fibrosis Registry. Phenotypic characteristics were compared with those of pancreatic insufficient (PI) and pancreatic sufficient (PS) cystic fibrosis (CF) subjects in the Registry (CF cohort).

RESULTS

Forty-two subjects with D1152H alleles were identified. Features leading to diagnosis included chronic sinopulmonary disease (n = 25), congenital absence of the vas deferens (n = 11), systematic neonatal screening (n = 4), and genetic counseling (n = 2). Median age at diagnosis was 33 [interquartile range (IQR, 24-41)] years in D1152H subjects. Median sweat chloride concentrations were 43.5 (39-63) mmol/l in D1152H subjects and were markedly lower than in PI and PS CF subjects (p < 0.05). Bronchiectasis was present in 67% of D1152H subjects, but Pseudomonas aeruginosa colonization and pancreatic insufficiency were present in <30% of subjects. Estimated rates of decline in forced expiratory volume in 1 s (FEV(1)) were lower in D1152H subjects vs PI CF subjects (p < 0.05). None of the D1152H subjects identified since 1999 had died or required lung transplantation.

CONCLUSIONS

When present in trans with a CF-causing mutation, D1152H causes significant pulmonary disease, but all subjects had prolonged survival.

[Specific aspects and care of lung involvement in adults with cystic fibrosis]

Respiratory impairment is present in almost all adult cystic fibrosis patients and makes the prognosis. Viscous, infected and abundant secretions, inflammation and bronchial oedema, bronchoconstriction and respiratory muscle fatigue lead to airway obstruction, bronchiectasis and respiratory failure. The disease is preferentially located in the upper lobes. Exacerbations of the disease are due to bronchial infections and are often responsible for drops of the respiratory function. Regular spirometric surveillance is fundamental for the prognosis and the assessment of the effects of the treatment. Among adult patients chronic colonisation with mucoid and often multiresistant strains of Pseudomonas Aeruginosa are common. It is treated with i.v. high doses antibiotic courses and nebulized antibiotics between i.v. courses. Respiratory failure may require long term oxygen and non invasive mechanical ventilation. Systemic hypervascularization around the bronchiectasis may lead to moderate to severe hemoptysis, which may require embolization. Pneumothorax are associated with poor prognosis and are treated by pleural drainage and if failure by thoracoscopy.

[Pleuropulmonary fibrosis and bromocriptine]

From a personal case and a review of the literature, it is recalled that bromocriptine may induce pleuropulmonary fibrosis. The various presentations of this condition are described. The index patient is a 56-year-old man, with Parkinson disease and a negative history for respiratory disease, who was taking bromocriptine in a high dose (60 mg/d). Under this treatment, he exhibited weight loss and an inflammatory syndrome and developed interstitial pneumopathy with secondary pleuropulmonary fibrosis, which resolved in part once therapy was discontinued. Bromocriptine, which is an ergot alcaloid with dopaminergic properties, has been used since 1965 in therapy. Its indications, which at the outset were restricted to endocrinology, were extended in 1972 to Parkinson disease, with a significant increase in dosages from 1979. Its responsibility in pleuropulmonary fibroses was suspected in 1981 by Rinne on data from 5 patients. As of now, 8 cases have been reported. All are Parkinson patients who, after a variable time interval (15 days to 3 years), developed a uniform picture of pleuropulmonary disease with rapidly increasing dyspnea upon exertion and deterioration of general health. These features mirror inflammation then fibrosis of the pleura and lung tissue, which results in a variable degree of chronic restrictive respiratory failure. The course is equally uniform, with partial resolution under corticosteroid therapy and more or less significant residual fibrosis at discontinuation of treatment. Immunoallergic rather than toxic or vasomotor mechanisms seem involved.(ABSTRACT TRUNCATED AT 250 WORDS)