Pulmonary manifestations and function tests in children genetically diagnosed with FMF.

Familial Mediterranean fever (FMF) is characterized by recurrent episodes of peritonitis, pleuritis, and synovitis. Among the pulmonary manifestations of FMF, pleuritis is the most common. Long-term sequelae of the respiratory system have not been described in FMF patients. We describe the pulmonary manifestations and function tests in a group of children who were found by genetic screening to be homozygous for the FMF gene. We surveyed 48 patients of Mediterranean extraction (aged 6-18 years) who were evaluated for a variety of pulmonary symptoms, and in whom clinical and genetic studies confirmed a diagnosis of FMF. All patients underwent complete pulmonary function tests, which included spirometry, body plethysmography, and single-breath carbon monoxide diffusion (Dlco). Forty percent of the Jewish patients, but only 8% of the Arab patients (P < 0.001), suffered from pulmonary manifestations during an attack of FMF. Jewish patients who were homozygotes for the M694V mutation suffered significantly more from episodes of pleuritis, cough, and rapid, shallow breathing than Arab patients, who were either homozygotes for the V726A mutation or bore any other combination of mutations. Three patients (6%) had mild restrictive lung disease, all of them homozygotes for the M694V mutation. In 3 further patients, obstructive lung impairment was found. Pulmonary manifestations during FMF attacks are significantly more common in the Jewish population bearing the M694V mutation. Restrictive lung impairment was found in a small number of these patients with a severe course of the disease; however, the series is too small to draw conclusions about long-term sequelae of the respiratory system in FMF patients.