Circulating immune complexes in cystic fibrosis.

The presence or absence of circulating immune complexes (CIC) was studied longitudinally over a period of 15 months in 17 patients with cystic fibrosis. (CF). Using the Raji cell assay, CIC were found in 47% of patients. Presence of immune complexes did not correlate with age at midpoint of the study severity of disease, acute pulmonary exacerbations, progression of lung disease, or nonspecific, humoral and cellular immune functions. In addition, the presence of CIC did not correlate with colonization with Pseudomonas aeruginosa, Staphylococcus aureus, Hemophilus influenzae, or streptococcus species (viridans or pneumoniae). Because CIC were present in patients without concurrent sputum colonization with Pseudomonas aeruginosa, antigens other than components of this organism may be capable of forming CIC in CF. The clinical and pathologic significant of CIC in CF remains to be determined.