Lymphoblastic stimulation test with food proteins in digestive intolerance to cow's milk and in infant diarrheas

The lymphoblastic stimulation test (LST) with cow's milk proteins was performed in 114 infants. In 42 infants, digestive intolerance to cow's milk proteins (CMI) was suspected; withdrawal-rechallenge test confirmed intolerance in 34, and disproved it in the other eight patients. Of the other patients, 17 had acute gastroenteritis, 11 had postgastroenteritis subacute diarrhea, 12 had gluten intolerance, 14 had intractable diarrhea, and 18 had no digestive disorders. Of the 34 infants with CMI, 27 (79%) had a positive LST to one or more cow's milk proteins. Of the 34 positive LST patients, 12 also had soya intolerance; nine of these 12 infants (75%) had positive LST to soya. Of the eight infants who had a negative cow's milk rechallenge test, five (62%) had a positive LST. In the other groups, results were also positive in 12-27% of those having diarrhea of infectious origin or gluten intolerance, and in none of the infants without digestive disorders. Of the 14 cases of severe intractable diarrhea, 12 (86%) were also LST-positive, but CMI could not be excluded. LST was positive, particularly in diarrheas of neonatal origin. Lymphoblastic stimulation was induced more frequently by casein than by beta lactoglobulin, and least frequently by alpha lactalbumin. In conclusion, LST is frequently positive in CMI, but is not sufficiently specific to be a reliable diagnostic examination.