Some aspects of immunity in patients with cystic fibrosis.

Various aspects of the immune status were examined in patients with cystic 
fibrosis (CF) and the following observations were made. Ten per cent 
of the CF patients had elevated or reduced serum IgG concentrations 
and there seems to be a transient low serum IgA concentration 
in the same number. Serum IgM concentrations were normal in CF 
patients. Normal levels of the three serum immunoglobulins (IgG, IgA and 
IgM) were detected in the siblings and heterozygotes. Serum IgE concentrations 
were elevated in 32% of patients with CF but normal concentrations 
were detected in heterozygotes and siblings. Precipitating antibodies to various antigens 
and allergens were detected in the sputum of most patients with 
CF, but their sera contained lower or undetectable titres of these 
antibodies. The precipitating antibodies in CF sputum to bacteria, to agar, 
to seminal fluid, to urine and to human serum may be 
related to a common antigenic determinant of the glycoproteins present in 
all these fluids. The total protein concentration in the sputum of 
CF patients seemed to reflect the extent of lung damage. The 
third component (C3) of serum complement concentration was normal, or moderately 
elevated in all CF patients tested. Serum transferrin concentrations were normal 
in CF patients but their prealbumin levels were depressed, suggesting marginal 
undernutrition. Peripheral blood lymphocyte transformations with PHA and PWM appear to 
be normal in CF patients. 