carboxypeptidase-b and Pancreatic-Diseases

Carboxypeptidase B from the pancreatic gland may exist in three different molecular and immunoreactive forms: the proenzyme, the active enzyme, and the activation peptide.. To investigate levels of procarboxypeptidase B (proCAPB) and its activation peptide in serum in acute pancreatitis to test the accuracy of these two variables as markers for the diagnosis of acute pancreatitis and for prediction of pancreatic necrosis. To elucidate whether leakage of proenzymes and activation of proenzymes reflect two different pathophysiological events in acute pancreatitis.. Sera from patients with acute pancreatitis (n=85) and acute abdominal pain of non-pancreatic origin (n=53) were analysed for proCAPB and its activation peptide. Patients with pancreatitis were divided into necrotising (n=33) and oedematous attacks (n=52) using contrast enhanced computed tomography. Accuracy was determined using receiver operating characteristic curve analysis.. Immunoreactive carboxypeptidase B activation peptide (ir-CAPAP) concentration in serum on admission was 0.7 nmol/l (0-18.1) in patients with oedematous pancreatitis compared with 5.8 nmol/l (1.9-34) in patients with later development of pancreatic necrosis. Elevated levels of the activation peptide on admission correlated with an accuracy of 92% to later development of pancreatic necrosis. Ir-proCAPB concentration in serum on admission was 16.0 nmol/l (1.4-50.5) in all patients with acute pancreatitis versus 0.3 nmol/l (0-3.6) in patients with non-pancreatic acute abdominal disorders. Cases with oedematous pancreatitis had ir-proCAPB levels of 15.4 nmol/l (1.4-50.5) versus 19.1 nmol/l (2.7-36.1) in cases with later development of pancreatic necrosis. Measurement of the proenzyme can thus be useful for the diagnosis of acute pancreatitis (accuracy 99%) but levels did not correlate with later development of pancreatic necrosis (accuracy 56%).. Leakage of proenzymes occurs in acute pancreatitis, irrespective of severity, while development of pancreatic necrosis occurs only when there is activation of the proenzymes.

Topics: Abdominal Pain; Acute Disease; Adult; Aged; Aged, 80 and over; Biomarkers; Carboxypeptidase B; Carboxypeptidases; Enzyme Activation; Enzyme Precursors; Female; Humans; Male; Middle Aged; Necrosis; Pancreas; Pancreatic Diseases; Pancreatitis; ROC Curve; Statistics, Nonparametric; Tomography, X-Ray Computed

Specific pancreatic oncofetal proteins have been discovered in man and a species of hamster using polyclonal antisera against fetal pancreatic extracts. Two main components in the Mr range of 80 kDa and 58 kDa (hamster) and 110 kDa and 58 kDa (man) were detected in pancreatic fetal extracts, by the "Western blot" technics. Two monoclonal antibodies, namely J28 directed against the human 110 kDa component (FAP protein) and B4 directed against the hamster 58 kDa component (FP protein) have been prepared. The B4 cross-reacts with the homologous human antigen. These monoclonal antibodies have shown that both proteins are antigenically unrelated, although they share common properties such as association to development of exocrine pancreas and high tissue specificity. The expression of both proteins increases in the case of pancreatic cancer but localisation varies. FAP protein is found in peritumoral acinar tissue, whereas FP protein is expressed in transformed cells. FAP protein is a serum marker for pancreatic pathologies and combined with CA 19-9 antigen assay it provides a serum test which is almost specific for cancer of the pancreas with near 100% sensitivity.

Topics: Animals; Antibodies, Monoclonal; Antigens, Neoplasm; Biomarkers; Blotting, Western; Carboxypeptidase B; Carboxypeptidases; Cricetinae; Humans; Immunohistochemistry; Pancreas; Pancreatic Diseases; Proteins