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Immunoreactive trypsin in blood in newborns (test for congenital cystic fibrosis)
Medical expert of the article
Last reviewed: 05.07.2025
Cystic fibrosis (mucoviscidosis) is a fairly common disease. Mucoviscidosis is inherited in an autosomal recessive manner and is found in 1 in 1,500-2,500 newborns. Due to early diagnosis and effective treatment, the disease is no longer considered to be limited to childhood and adolescence. As treatment and diagnostic methods improve, more and more patients reach adulthood. Currently, 50% of patients survive to age 25. The main method of early postnatal diagnosis of cystic fibrosis is to determine the concentration of trypsin in the blood serum of newborns.
Reference values (norm) of the concentration of immunoreactive trypsin in blood serum
Age |
Immunoreactive trypsin, µg/l |
Blood from the umbilical cord |
23.3±1.9 |
0-6 months |
31.3±5.4 |
6-12 months |
37.1±6.9 |
1-3 years |
29.8±1.8 |
3-5 years |
28.3±3.2 |
5-7 years |
35.7±3.6 |
7-10 years |
34.9±2.2 |
Adults |
33.3±11.1 |
An increase in serum trypsin concentration in children in the first few weeks after birth indicates the presence of cystic fibrosis, and therefore its determination is considered an effective screening method. As the disease progresses and true pancreatic insufficiency develops, serum trypsin concentration decreases.
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