The precipitins and hypersensitivity reactions in cystic fibrosis.

The large number and wide variety of precipitins detected in the sputum 
of cystic fibrosis patients suggest that the precipitins may be nonprotective 
and even harmful to the patients. These sputum precipitins were directed 
principally against food, fungi, bacteria, and human body tissue. On the 
other hand, precipitins to Staphylococcus alpha-hemolysin was the main type of 
immunoprecipitin detected in CF serum and was found in 60% of 
the serum specimens examined. It seems likely that the precipitins in 
patients with CF may be involved in the formation of immune 
complexes which, in conjunction with complement, may be responsible for the 
respiratory and gastrointestinal lesions that are common in patients with CF. 
The immune complexes may be the result of excess food and 
bacterial antigens escaping across the gut and lungs as a result 
of some abnormality of the SIgA system. Over 80% of the 
sputum specimens tested gave positive precipitins in agar gel against human 
seminal fluid and colostrum, suggesting that some of the antibodies formed 
in CF patients could be directed against host tissue, and may 
account for an autoimmune-type reaction in CF. Crossreaction between the high-titer 
antibody to Staphylococcus and basement membrane of lungs and pancreas, with 
complement activation, may occur in CF and required further study. The 
high number of B-cells, as detected by antibody, coated complement, activated 
sheep erythrocytes, and EAC rosettes, may be partly responsible for the 
synthesis of the variety of antibodies detected in CF patients. 