Letter: Sulphate incorporation of leucocytes from patients with cystic fibrosis.

In preliminary studies of short-term leukocyte cultures using Na2-35SO4 incorporation into cetyl-pyridinium-chloride 
(C.P.C.)-precipitable material (presumably glycosaminoglycans, G.A.G.), we have found significant variation among 
C.F. patients and their parents (obligate heterozygotes). This biochemical heterogeneity is 
comparable to what has been reported in fibroblast cultures and serum. 
The amount of Na2-35SO4 incorporated into G.A.G. material found in both 
the incubation medium and the cells from C.F. patients is significantly 
increased over normals. A similar analysis between normals and heterozygotes shows 
no significant difference in Na2-35SO4 incorporation into G.A.G. material of the 
cells. However, 4 out of 6 heterozygotes appeared to show a 
pattern of increased incorporation into material found in the incubation medium 
(indicated by a higher mean than the normal donors). These results 
suggest yet another system to study the effects of the C.F. 
gene. The incorporation of Na2-35SO4 into G.A.G. material of C.F. leukocyte 
cultures gives additional evidence for the genetic heterogeneity in this disorder. 
