Serum lipase levels pre and post Lundh meal: evaluation of exocrine pancreatic status in cystic fibrosis

Determination of pancreatic function is essential in cystic fibrosis. The m ost-reliable method is by measuring pancreatic enzymes in the duodenum foll owing intravenous or oral stimulation. However, this is invasive, time cons uming, and expensive. Indirect tests are non-invasive but lack accuracy. Th is study examines a simple test which combines pancreatic stimulation by Lu ndh meal and sequential serum lipase measurements. The test was performed o n three groups: group A, 36 cystic fibrosis patients carrying two mutations associated with severe disease and pancreatic insufficiency (Delta F508, W 1282X, G542X, N1303K, S549R); group B, 8 compound heterozygote cystic fibro sis patients carrying one mutation causing mild disease with pancreatic suf ficiency (3849 + 10 kb C --> T); group C, 17 healthy individuals. Basal lip ase levels were 2-16.5, 16.4-73, and 8.5-27.8 U/l in groups A, B, and C, re spectively, with some overlapping between groups. There were three patterns of lipase activity(1) consistently low levels (group A) suggested a severe ly affected insufficient pancreas; (2) normal basal levels followed by a li near rise peaking 30 min after the meal (found in 16 of 17 healthy individu als and 3 patients of group B) reflecting an unaffected sufficient pancreas ; (3) elevated lipase levels not influenced by the meal (5 patients of grou p B). This reflects an ongoing destructive process in the pancreas which wi ll eventually result in conversion from pancreatic sufficiency to pancreati c insufficiency. Hence serum lipase activity prior to and 30 min after Lund h meal is a good indicator of pancreatic status allowing categorization of cystic fibrosis patients as pancreatic insufficient, pancreatic sufficient, or pancreatic sufficient with late conversion to insufficiency.