Abnormal response of cultured lymphocytes to phytohemagglutinin and autologous serum in cystic fibrosis.

Lymphocytes from adults homozygous or heterozygous for cystic fibrosis show biochemical abnormalities 
when cultured for 48 hours in the presence of phytohemagglutinin and 
autologous serum. In contrast to the 45 per cent increase in 
total protein and beta-glucuronidase concentrations seen in healthy control subjects when 
measured per 10(10) cells, both concentrations decreased by 1 per cent 
in adults heterozygous for cystic fibrosis and by 18 per cent 
in adults homozygous for cystic fibrosis. The abnormal response of the 
lymphocytes from persons with cystic fibrosis was due to a serum 
factor and not to any intrinsic abnormality of the lymphocytes. An 
abnormal response to hytohemagglutinin occurred in only 14 per cent of 
44 healthy control subjects, but in 100 per cent of 14 
adults homozygous for cystic fibrosis and in 85 per cent of 
26 adults presumed to be heterozygous for cystic fibrosis. As a 
result of this phenomenon, lymphocytic beta-glucuronidase concentrations were significantly lower than 
normal in patients with cystic fibrosis when the cells were cultured 
with phytohemagglutinin and autologous serum. The demonstration of this phenomenon in 
both homozygotes and presumed heterozygotes (parents) suggests a relationship to the 
genetic defect in cystic fibrosis. 