IMMUNE COMPLEXES IN CYSTIC FIBROSIS

Abstract

Eleven patients with cystic fibrosis (CF) chronically infected with mucoid Pseudomonas aeruginosa and 10 patients without P. aeruginosa infection were examined for occurrence of circulating immune complexes, for immune complex deposits in the dermo-epidermal junction of the skin and for precipitins against P. aeruginosa, Staphylococcus aureus, Haemophilus influenzae and Diplococcus [Streptococcus] pneumoniae antigens. The serum concentrations of haptoglobin, orosomucoid, immunoglobulins [Ig], C1q [q subunit of complement component 1 ], C3 [complement component 3], C4 [complement component 4], total hemolytic C, antinuclear and rheumatoid factor activities and white blood cell counts and erythrocyte sedimentation rates were determined. Six patients from the chronically P. aeruginosa-infected group, exhibiting a spectrum of serum precipitins against P. aeruginosa antigens, had immune complexes in the serum; 1 patient (suffering from selective IgA deficiency) without P. aeruginosa infection was positive for soluble immune complexes. Granular deposits of IgM were found in the skin of 10 of the chronically P. aeruginosa infected patients and in 7 of the patients without P. aeruginosa infection. A few patients in both groups had dermo-epidermal deposits of C1q, C3 or fibrinogen. Eight of the patients in the chronically infected group and 5 in the group without P. aeruginosa infection had organ non-specific antinuclear factors. The haptoglobin levels appeared to be elevated in the chronically infected patients (P < 0.05). None of the other parameters showed any significant difference between the 2 groups.