Serum-gastrin in vitiligo

Type 3 autoimmune polyglandular syndrome (APS-3) or type 3 multiple autoimmune syndrome (MAS-3): an expanding galaxy

BACKGROUND

The number of recognised distinct autoimmune diseases (AIDs) has progressively increased over the years with more than 100 being reported today. The natural history of AIDs is characterized by progression from latent and subclinical to clinical stages and is associated with the presence of the specific circulating autoantibodies. Once presented, AIDs are generally chronic conditions. AIDs have the tendency to cluster and co-occur in a single patient. Autoimmune thyroid diseases (AITD) are the most prevalent of AIDs in the world population, and about one-third of the AITD patients also present with a non-thyroid AID during their life-span. Furthermore, patient with non-thyroid AIDs often presents with a form of AITD as a concurrent condition. Many of the clusters of AIDs are well characterized as distinctive syndromes, while some are infrequent and only described in case reports.

PURPOSE

In this review, we describe the wide spectrum of the combinations and the intricate relationships between AITD and the other AIDs, excluding Addison's disease. These combinations are collectively termed type 3 Autoimmune Polyglandular Syndrome (APS-3), also called type 3 Multiple Autoimmune Syndrome (MAS-3), and represent the most frequent APS in the world populations.

CONCLUSIONS

Numerous associations of AITD with various AIDs could be viewed as if the other AIDs were gravitating like satellites around AITD located in the center of a progressively expanding galaxy of autoimmunity.

Gastric outlet obstruction as a consequence of a duodenal web masquerading as gastrinoma in an adult

We present the case of a 24-year-old man with recurrent peptic ulcers and hypergastrinemia, in whom a multidisciplinary investigation for gastrinoma revealed a duodenal web. The affected duodenal segment was excised, and a gastroduodenostomy with highly selective vagotomy was performed. Postoperative serum gastrin levels returned to the normal range over the next 6 weeks. Congenital duodenal anomalies are unusual causes of gastric outlet obstruction in adults. Chronic gastric outlet obstruction secondary to an adult duodenal web can induce neurohumoral changes in gastric function, which enhance both acid output and gastrin secretion. This case reminds clinicians to consider congenital anomalies in adults presenting with recurrent peptic ulcers and hypergastrinemia.

Ocular abnormalities associated with cutaneous melanoma and vitiligolike leukoderma

Several varieties of ocular pathology are associated with acquired cutaneous hypomelanosis (leukoderma; vitiligo). Our current study was undertaken to investigate the relationship between ophthalmologic disorders and a specific depigmentary phenomenon, the vitiligolike leukoderma of cutaneous melanoma. Over the past 14 years, eight patients with cutaneous melanoma and widespread areas of hypopigmentation were identified at the Pigmented Lesion Clinic of the Massachusetts General Hospital. The seven patients who underwent ophthalmologic examination had pigment-related ocular abnormalities. Among these were inflammations of the uveal tract in three patients, heterochromia in two, halo nevi of the choroid in one, and hypopigmentation and/or atrophy of the retinal pigment epithelium or choroid in four. Our findings demonstrate that ocular disease may be a component in a syndrome consisting also of cutaneous melanoma and vitiligolike leukoderma and suggest the need for complete ophthalmologic examinations in patients with melanoma and leukoderma.

The requirement for gastrin measurements

In order to evaluate the clinical requirement for gastrin measurements, we examined all gastrin measurements requested over 1.5 years in a homogeneous population of 5.1 million inhabitants. Gastrin was quantitated with a radioimmunoassay that measured bioactive gastrins with equimolar potency. We received 1392 serum samples from 931 patients. In 394 samples from 121 patients the gastrin concentration was above the limit of the reference interval (50 pmol/l). Of the 121 patients, 19 were known Zollinger-Ellison patients followed for control of the therapy. In 11 previously unknown patients the gastrin analysis suggested presence of gastrin-producing tumours. Of these, four had classical Zollinger-Ellison syndromes, three had mixed endocrine tumours without peptic ulcer, and four were awaiting final confirmation of gastrinomas. Two vitiligo patients were hypergastrinaemic suggesting latent pernicious anaemia. Upon second measurement the plasma gastrin concentrations were within the reference interval in 14 previously hypergastrinaemic ulcer patients. In the remaining 75 patients the hypergastrinaemia was secondary to other gastrointestinal diseases. The results indicate that diagnosis, localization, and therapeutic control of gastrinomas require 200 gastrin measurements per million inhabitants per year. We suggest that this number be used in planning gastrin-assay services.

Gastrinoma

Although there are multiple etiologies of clinical hypergastrinemia, the most important cause is gastrinoma [Zollinger-Ellison (ZE) syndrome]. The most significant advance in the management of patients with the ZE syndrome has been the development of the ability to establish firmly the correct preoperative diagnosis by radioimmunoassay. We believe that all patients who have the ZE syndrome should undergo operation for two reasons: to identify and resect all tumor and because in patients in whom no tumor is found or in whom all tumor cannot be resected, the most reliable relief of hypersecretory symptoms for the life of the patient can be achieved by total gastrectomy.

Is copper hepatotoxic in primary biliary cirrhosis?

In primary biliary cirrhosis (PBC) liver copper retention occurs as a complication of cholestasis. By analogy with Wilson's disease, it has been suggested that copper retention is hepatotoxic in PBC, and this has been the rationale for the use of D-penicillamine in this disease. The hypothesis that copper is hepatotoxic in PBC has not been tested and in this study we have evaluated the role of liver copper retention in the pathogenesis of PBC. Sixty-four patients with PBC have been studied. Fifty-four had increased liver copper concentrations. Liver cell synthetic function was well preserved. All the patients had normal prothrombin times, and only two had subnormal serum albumin concentrations. There was no correlation between liver copper concentrations and the degree of liver cell damage assessed biochemically (aspartate transaminase), and histologically. Electron microscopy was performed on liver biopsies from five patients with markedly increased liver copper concentrations. The liver cell ultrastructure was compatible with cholestasis. Liver cells contained electron dense lysosomes, which were shown to contain copper and sulphur by x-ray probe microanalysis. The characteristic organelle changes associated with copper toxicity in Wilson's disease were not observed. The biochemical, histological, and histochemical differences between PBC complicated by liver copper retention, and Wilson's disease, indicates that there are differences in the handling of copper in these disease. In this study we could find no evidence to suggest that copper plays an important role in the pathogenesis of liver dysfunction in PBC.

Gastrin concentrations in serum and gastric mucosa in patients with pernicious anaemia

Sessile polyps in the antrum were found in 12 of 51 patients with pernicious anaemia. During gastroscopy, mucosal biopsies for gastrin determination were taken from the antrum and fundus and from the polyps. Patients with high gastrin concentration in the antral mucosa showed high serum gastrin concentrations, while most patients with low antral gastrin concentrations also had low serum gastrin values. On an average, the gastrin concentrations in the antrum were approximately 10 times, and those in the fundus approximately 100 times, higher than the corresponding values obtained in a reference group. The gastrin content in the polyps was not different from that in the surrounding antral mucosa. This study suggests that the polyps are not due to a functional hypertrophy of the antral mucosa caused by locally increased production of gastrin.

Disturbed islet-cell function related to endogenous gastrin release. Studies on insulin secretion and glucose tolerance in pernicious anemia

The insulin and gastrin response to oral glucose, intravenous glucose, or a protein-rich meal were measured in 44 nondiabetic patients with pernicious anemia (PA) and in 44 control subjects. 36 of the PA-patients had hypergastrinemia, while serum gastrin concentrations in the remaining eight patients were below normal. Three hypergastrinemic PA-patients were in addition studied during an oral glucose loading with synchronous intravenous infusion of gastrin-17. During both oral and intravenous glucose tests blood glucose concentrations were similar in patients and in controls. After ingestion of protein blood glucose concentrations in PA-patients with hypergastrinemia were above those of the controls (P less than 0.05). Parenteral infusion of gastrin-17 during oral glucose loading also increased blood glucose concentrations above the levels observed after glucose alone. In PA-patients with hypergastrinemia the insulin response was augmented in all tests. In patients with hypogastrinemia serum insulin concentrations were lower than normal in the fasting state and during stimulation with glucose intravenously (P less than 0.01). In hypergastrinemic patients serum gastrin concentrations decreased after oral as well as intravenous glucose administration. The decrease was larger during the oral test. In hypogastrinemia oral glucose induced, as in controls, a small initial rise followed by a slow fall in serum gastrin concentrations. No variations were seen in these patients during the intravenous glucose infusion. Gel filtration of serum from hypergastrinemic patients disclosed a decrease in the concentrations of all four main components of gastrin during the glucose loadings. Taken together with earlier studies on the effect of exogenous gastrin the results suggest that endogenous hypergastrinemia induces hyperglycemia and potentiates insulin secretion. In contrast hypogastrinemia is associated with hypoinsulinism.