Various novel biochemical markers indicate pancreatic cellular injury more
accurately than serum amylase or lipase. One of these is a non-enzymatic se
cretory protein called pancreatitis-associated protein (PAP). The main func
tion of PAP is unclear at present but it may be an acute phase protein int
he defence reactions of pancreatic cells. The protein was characterized in
1984 as a serum marker of pancreatitis. The serum PAP is expressed 6 hours
after the induction of pancreatitis, and it increases to maximal levels wit
hin 2-4 days: PAP is not sufficiently sensitive for the diagnosis of acute
pancreatitis in the emergency room. The sensitivity and specificity of PAP
in the differentiation of severe from mild pancreatitis is between 60-70%.
This is not superior to serum CRP assays or CT scans. PAP increases in panc
reatic cellular injury without pancreatitis (subclinical cell damage, graft
rejection) where PAP may have a diagnostic role.