Effects of cystic fibrosis sera on Proteus vulgaris motility.

Suspensions of Proteus vulgaris were rapidly agglutinated by serum from cystic fibrosis 
patients. Serum from obligate heterozygotes exhibited a mean agglutination time that 
was significantly less than that observed for 128 controls. The agglutinating 
property was observed to be transmitted through several generations and through 
both maternal and paternal branches of the pedigrees. Qualitative differences were 
noted, with CF sera inducing the formation of clumps that were 
two- to 10-fold larger than those observed in heterozygotes. The serum 
factor responsible for P. vulgaris agglutination was heat sensitive, destroyed by 
pronase, and neutralized by anti-human whole serum. The CF serum retained 
agglutinating activity following preincubation with anti-human IgG, IgA, B1E, and B1A/B1C. 
