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October 1956

Cystic Fibrosis of the Pancreas with Varying Degrees of Pancreatic Insufficiency

Author Affiliations

From the Division of Laboratories and Research, Children's Medical Center, and Department of Pediatrics, Harvard Medical School.

AMA Am J Dis Child. 1956;92(4):347-368. doi:10.1001/archpedi.1956.02060030341004

The diagnosis of cystic fibrosis of the pancreas rests upon characteristic laboratory findings. In the past, the most reliable test was based on a study of the duodenal aspirate for pancreatic enzyme activity. The absence or marked diminution of tryptic activity in the duodenal aspirate in childhood was considered pathognomonic of cystic fibrosis of the pancreas, with rare exception. Conversely, the presence of tryptic activity was considered sufficient evidence to discard this diagnosis. The exact end-point of tryptic activity for this differentiation has always been difficult to define. Most observers drew the line of demarcation at tryptic activity less than 10% of normal. As a result of a large clinical experience coupled with an active and continuous interest in the development of better diagnostic methods, we feel a need for broadening the so-called classical criteria for the diagnosis of cystic fibrosis. As early as 1947 we had evidence that this