Protein, IgA, secretory IgA, IgG and electrolytes as parameters of parotid gland function in children with cystic fibrosis.

To study the parotid gland function in children with cystic fibrosis we 
investigated parotid saliva specimens of 18 such patients. We compared the 
results with a control group of 12 healthy children of the 
same age and sex. Furthermore, children with bronchial asthma and chronic 
bronchitis were examined. The flow rate of the parotid and the 
protein output without stimulation were nearly the same for the four 
groups. In patients with CF the protein output after stimulation was 
significantly lower. An increased level of sodium was observed in the 
stimulated secretion and the unstimulated saliva as well. In CF children 
we found a significant higher output of sodium in both stimulated 
parotid saliva and unstimulated parotid saliva. The IgG output of the 
gland after stimulation was found to be slightly reduced in patients 
with CF in comparison to healthy children. The output of the 
gland for IgA after stimulation was observed to be strongly reduced 
for the group with CF and for the group with bronchial 
asthma. The decreased output of the gland for secretory IgA after 
stimulation was demonstrated again in CF and in bronchial asthma in 
comparison with healthy persons. The increased sodium concentration in parotid saliva 
may be caused in a similar way as the electrolyte abnormality 
of sweat in CF patients, namely by a decreased net reabsorption 
of sodium. Due to the result of an increased electrolyte output 
and decreased immunoglobulin output of parotid gland we can suppose that 
the molecular magnitude plays its role in this disturbance. 