Double doses of secretin contribute to diagnosis of Zollinger-Ellison syndrome in secretin and selective arterial secretion injection tests--a case report

Diagnostic efficacy of the secretin stimulation test for the Zollinger-Ellison syndrome: an intra-individual comparison using different dosages in patients and controls

BACKGROUND/AIMS

The secretin stimulation test is the principal diagnostic tool to identify Zollinger-Ellison syndrome (ZES). We investigated, by intra-individual comparison, which dose of secretin results in the highest diagnostic efficacy to identify the ZES.

METHODS

Fifty-seven paired secretin stimulation tests, using both 0.26 microg/kg and 0.78 microg/kg secretin, performed in 13 ZES patients and 12 controls, were analyzed and the findings confirmed in a validation cohort.

RESULTS

A gastrin increase of >100 ng/l was found to be the most sensitive and specific criterion for a positive test. Higher gastrin increases after 0.78 microg/kg compared to 0.26 microg/kg secretin contributed to a slightly more sensitive (82.9 vs. 80.5%) but less specific (68.8 vs. 81.3%) test. A validation cohort, with 98 tests using 0.26 microg/kg secretin in 21 ZES patients and 39 controls, provided similar results. In ZES patients with normal fasting serum gastrin levels (<100 ng/l), there was no diagnostic benefit from the use of a higher secretin dose.

CONCLUSIONS

The 0.26 microg/kg secretin stimulation test has the best diagnostic efficacy for the ZES. and IAP.

Serum gastrin in Zollinger-Ellison syndrome: II. Prospective study of gastrin provocative testing in 293 patients from the National Institutes of Health and comparison with 537 cases from the literature. evaluation of diagnostic criteria, proposal of new criteria, and correlations with clinical and tumoral features

In two-thirds of patients with Zollinger-Ellison syndrome (ZES), fasting serum gastrin (FSG) levels overlap with values seen in other conditions. In these patients, gastrin provocative tests are needed to establish the diagnosis of ZES. Whereas numerous gastrin provocative tests have been proposed, only the secretin, calcium, and meal tests are widely used today. Many studies have analyzed gastrin provocative test results in ZES, but they are limited by small patient numbers and methodologic differences. To address this issue, we report the results of a prospective National Institutes of Health (NIH) study of gastrin provocative tests in 293 patients with ZES and compare these data with those from 537 ZES and 462 non-ZES patients from the literature. In 97%-99% of gastrinoma patients, an increase in serum gastrin post secretin (Delta secretin) or post calcium (Delta calcium) occurred. In NIH ZES patients with <10-fold increase in FSG, the sensitivity/specificity of the widely used criteria were as follows: Delta secretin > or =200 pg/mL (83%/100%), Delta secretin >50% (86%/93%), Delta calcium > or =395 pg/mL (54%/100%), and Delta calcium >50% (78%/83%). A systematic analysis of the sensitivity and specificity of other possible criteria for a positive secretin or calcium test allowed us to identify a new criterion for secretin testing (Delta > or =120 pg/mL) with the highest sensitivity/specificity (94%/100%) and to confirm the commonly used criterion for calcium tests (Delta > or =395 pg/mL) (62%/100%). This analysis further showed that the secretin test was more sensitive than the calcium test (94% vs. 62%). Our results suggest that secretin stimulation should be used as the first-line provocative test because of its greater sensitivity and simplicity and lack of side effects. In ZES patients with a negative secretin test, 38%-50% have a positive calcium test. Therefore the calcium test should be considered in patients with a strong clinical suspicion of ZES but a negative secretin test. Furthermore, we found that some clinical (diarrhea, duration of medical treatment), laboratory (basal acid output), and tumoral (size, extent) characteristics correlate with the serum gastrin increase post secretin and post calcium. However, using the proposed criteria, the result of these provocative tests (that is, positive or negative) is minimally influenced by these factors, so secretin and calcium provocative tests are reliable in patients with different clinical, laboratory, and tumor characteristics. A systematic analysis of meal testing showed that 54%-77% of ZES patients have a <50% postprandial serum gastrin increase. However, 9%-20% of ZES patients had a >100% increase post meal, causing significant overlap with antral syndromes. Furthermore, we could not confirm the usefulness of meal tests for localization of duodenal gastrinomas. We conclude that the secretin test is a crucial element in the diagnosis of most ZES patients, the calcium test may be useful in selected patients, but the meal test is not helpful in the management of ZES. For secretin testing, the criterion with the highest sensitivity and specificity is an increase of > or =120 pg/mL, which should replace other criteria commonly used today.

Severe gastrointestinal involvement in systemic sclerosis

Gastrointestinal tract (GIT) is the most common organ system involved in systemic sclerosis (SSc). GIT involvement is mainly attributed to GIT dismobility and wide mouth diverticular. GIT involvement in SSc can be also severely debilitating and even life threatening. To our knowledge, the presence of gastrointestinal bleeding due to the presence of multiple peptic ulcers in scleroderma patients is not well described. In this case report, we describe a scleroderma patient with recurrent gastrointestinal bleeding due to multiple peptic ulcers, in which vagotomy, pyloroplasty, and cholocystectomy were performed and subcutaneous somatostatin was administered to discontinue the recurrent bleeding and stabilize her clinical condition.