Meconium plug syndrome, cystic fibrosis, and exocrine pancreatic deficiency [letter].

We have observed severe meconium plug syndrome (MPS) in a newborn infant 
who was found during the neonatal period to have extensive exocrine 
pancreatic deficiency. Cystic fibrosis was excluded by several sweat chloride tests. 
Our observation of MPS in a patient with exocrine pancreatic deficiency 
suggests that the MPS observed in the CF patients reported by 
Rosenstein is probably caused by pancreatic deficiency. The frequent occurrence of 
meconium ileus (MI) in CF and the rarity of MPS in 
CF is curious, since they may be different manifestations of the 
same pathologic process. Conceivably, MPS may occur with total absence of 
pancreatic enzymes (as in our patient and in a few patients 
with CF). Low levels of enzymes in CF may limit expression 
to meconium ileus. We wish to suggest the evaluation of exocrine 
pancreatic function in these patients even if CF has been excluded 
by sweat tests. - There is conflicting, albeit fragmentary, data suggesting 
that exocrine pancreatic deficiency may not be the sole cause of 
meconium obstruction in CF. Several investigators have suggested that MI may 
be the result of abnormal protein and mucoprotein secretions by the 
intestinal goblet cells and not from lack of pancreatic enzymes alone. 
While these observations suggest that exocrine pancreatic deficiency may not play 
a major role in all instance of meconium obstruction, it is 
important to note that there may be little correlation between the 
histologic appearance of the pancreas and exocrine function. 