TY - JOUR
T1 - Diagnostic value of fasting plasma peptide concentrations in patients with chronic diarrhea
AU - Schiller, Lawrence R.
AU - Rivera, Lydia M.
AU - Santangelo, William C.
AU - Little, Katherine H.
AU - Fordtran, John S.
PY - 1994/10
Y1 - 1994/10
N2 - To evaluate the utility of screening for multiple gastrointestinal peptides in the evaluation of patients with chronic diarrhea, we studied 193 patients referred for evaluation of chronic diarrhea and eight patients with known peptide-secreting tumors as a reference group. Fasting plasma samples were assayed for motilin, neurotensin, pancreatic polypeptide, somatostatin, substance P, vasoactive intestinal polypeptide, gastrin-releasing peptide, and calcitonin during a protocol evaluation for causes of chronic diarrhea. Although none of the referred patients were found to have tumors, abnormal levels of one or more peptides were found in 86 of 193 patients (45%). Abnormal plasma peptide levels were sometimes as high in these patients as in patients with known peptide-secreting tumors and would have led to mistaken diagnoses of tumors much more often than they would have led to correct diagnoses. The positive predictive value of elevation of any assayed peptide was<2% at realistic prevalence rates for peptide-secreting tumors; the negative predictive value of a series of normal results was>99%, but much of this was due to the rarity of these tumors. Patients with chronic diarrhea should not be screened routinely with a panel of plasma peptide assays in an effort to detect tumors; instead, peptide levels should be ordered selectively. Elevated fasting concentrations of the plasma peptides measured in this study are most likely epiphenomena due to diarrhea and should not be the sole basis for invasive diagnostic or surgical management of these patients.
AB - To evaluate the utility of screening for multiple gastrointestinal peptides in the evaluation of patients with chronic diarrhea, we studied 193 patients referred for evaluation of chronic diarrhea and eight patients with known peptide-secreting tumors as a reference group. Fasting plasma samples were assayed for motilin, neurotensin, pancreatic polypeptide, somatostatin, substance P, vasoactive intestinal polypeptide, gastrin-releasing peptide, and calcitonin during a protocol evaluation for causes of chronic diarrhea. Although none of the referred patients were found to have tumors, abnormal levels of one or more peptides were found in 86 of 193 patients (45%). Abnormal plasma peptide levels were sometimes as high in these patients as in patients with known peptide-secreting tumors and would have led to mistaken diagnoses of tumors much more often than they would have led to correct diagnoses. The positive predictive value of elevation of any assayed peptide was<2% at realistic prevalence rates for peptide-secreting tumors; the negative predictive value of a series of normal results was>99%, but much of this was due to the rarity of these tumors. Patients with chronic diarrhea should not be screened routinely with a panel of plasma peptide assays in an effort to detect tumors; instead, peptide levels should be ordered selectively. Elevated fasting concentrations of the plasma peptides measured in this study are most likely epiphenomena due to diarrhea and should not be the sole basis for invasive diagnostic or surgical management of these patients.
KW - carcinoid tumors
KW - chronic diarrhea
KW - endocrine tumors
KW - gastrointestinal peptides
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U2 - 10.1007/BF02090374
DO - 10.1007/BF02090374
M3 - Article
C2 - 7924745
AN - SCOPUS:0027997688
SN - 0163-2116
VL - 39
SP - 2216
EP - 2222
JO - Digestive Diseases and Sciences
JF - Digestive Diseases and Sciences
IS - 10
ER -