The various faces of autoimmune endocrinopathies: Non-tumoral hypergastrinemia in a patient with lymphocytic colitis and chronic autoimmune gastritis

Abstract

Serum gastrin levels exceeding 1000 pg/ml (normal, <100) usually raise the suspicion for a neuroendocrine tumor (NET) that secretes gastrin. Rarely, such elevated gastrin levels are seen in patients with pernicious anemia which most commonly is associated with autoimmune gastritis (AG). AG can occur concomitantly with other autoimmune disorders including lymphocytic colitis (LC). Gastrin stimulates enterochromaffin-like cells which increase histamine secretion. Histamine excess can cause diarrhea as can bacterial overgrowth or LC. We present a 57-year-old woman with diarrhea, sporadic epigastric pain, and bloating. She also had a history of interstitial cystitis and took pentosan polysulfate and cetirizine. She had no history of ulcers, renal impairment or carcinoid syndrome. Fasting serum gastrin was 1846 pg/ml. Esophagoduodenal gastroscopy and biopsies revealed chronic gastritis and a pH of 7 with low stomach acid. Serum gastrin and plasma chromogranin A were suggestive of a gastrinoma or NET. Pernicious anemia was unlikely. Imaging studies did not reveal any tumor. Random colonic biopsy was compatible with LC, possibly explaining her diarrhea, although we also considered excessive histamine from elevated gastrin, bacterial overgrowth, and pentosan polysulfate which can cause diarrhea and be misleading in this setting, pointing to the diagnosis of gastrinoma. At 4 year follow-up in 2012, fasting serum gastrin was 1097 pg/ml and the patient asymptomatic taking only cetirizine for nasal allergies. This case illustrates that diarrhea may be associated with very high serum gastrin levels in the setting of chronic gastritis, LC, and interstitial cystitis (pentosan use), without clear evidence for a gastrinoma or NET. If no history of ulcers or liver metastases is present in such cases, watchful observation rather than an extensive/invasive and costly search for a NET may be justified. Considering the various forms of polyglandular syndrome, this may represent a variant and we here provide an algorithm for working up such patients, while also reviewing literature on the intertwined relationship between the immune and endocrine systems.

Association of lymphocytic colitis and lactase deficiency in pediatric population

“…As previously reported, colonic lymphocytosis can occur in patients with Crohn disease, H. pylori, celiac disease, and certain medication usage; oftentimes, there is strong family history of autoimmune disease [14]. Our observation of these aspects correlates well with the known literature [13].…”

Graves' Disease, Hypoparathyroidism, Systemic Lupus Erythematosus, Alopecia, and Angioedema: Autoimmune Polyglandular Syndrome Variant or Coincidence?

“…Selected patients with GD and perhaps (unrecognized) parathyroid autoantibodies with a slowly developing destructive impact on the parathyroid glands may then develop overt hyoparathyroidism with rather low dose RAI ablation. Our case adds to the evolving spectrum of polyglandular syndromes and may represent PGS type 3 or 4 (30).…”

Gastric non-secreting neuroendocrine tumor and hypochlorhydria-related hypergastrinemia: a case report

“…pylori infection and autoimmune achlorhydric atrophic gastritis without or with pernicious anemia may lead to mild-to-moderate hypergastrinemia [4,5]. In our case, the absence of symptoms of classical gastrinoma and the persistence of extremely elevated gastrin after radical tumor excision rule out the diagnosis of Zollinger–Ellison syndrome.…”