Immune complexes in cystic fibrosis.

Eleven patients with cystic fibrosis (CF) chronically infected with mucoid P. aeruginosa and ten 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, S. aureus, H. influenzae and D. pneumoniae antigens. The serum concentrations of haptoglobin, orosomucoid, immunoglobulins, C1q, C3, C4 and total haemolytic complement, antinuclear and rheumatoid factor activities as well as white blood cell counts and erythrocyte sedimentation rates were determined also. The results indicated that 6 patients from the chronically P. aeruginosa infected group, exhibiting a spectrum of serum precipitins against P. aeruginosa antigens, also had immune complexes in the serum, while only one patient (suffering from selective IgA deficiency) in the group without P. aeruginosa infection was positive for soluble immune complexes. Granular deposits of IgM was 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 pactients in both groups had dermo-epidermal deposits of C1q, C3 or fibrinogen as well. Eight of the patients in the chronically infected group and five 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 less than 0.05). None of the other parameters showed any significant difference between the two groups.