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

Pathogenesis of Microscopic Colitis: A Systematic Review

BACKGROUND

Whereas the exact aetiology of microscopic colitis [MC] remains unknown, a dysregulated immune response to luminal factors or medications is the most accepted pathogenesis hypothesis.

METHODS

We conducted a systematic review of the pathogenesis of MC. We applied the Joanna Briggs Institute methodologies and the PRISMA statement for the reporting of systematic reviews [PROSPERO Trial Identifier: CRD42020145008]. Populations, Exposure of interest, and Outcome [PEO] questions were used to explore the following topics in MC: 1] intestinal luminal factors; 2] autoimmunity; 3] innate immunity; 4] adaptive immunity; 5] extracellular matrix; 6] genetic risk factors; and 7] mechanism of diarrhoea. A search was done in PubMed, Embase, and Web of Science up to February 2020. A narrative description was performed explaining the findings for each aspect of MC aetiopathogenesis.

RESULTS

Thirty-eight documents provided evidence for PEO1, 100 for PEO2, 72 for PEO3 and 4, 38 for PEO5, 20 for PEO6, and 23 for PEO7. The majority of documents were cohorts, case reports, and case series, with a few case-control and some experimental studies. Consistency among data provided by different studies was considered to support pathogenetic hypotheses. MC is a multifactorial disease believed to involve innate and adaptive immune responses to luminal factors, genetic risk, autoimmunity, and extracellular matrix alterations, all contributing by varied mechanisms to watery diarrhoea.

CONCLUSIONS

This is the first systematic review on the aetiology of MC supporting the notion that MC is a multifactorial disease. However, high-profile studies are lacking, and most evidence derives from small heterogeneous studies.

[An adult case of Hashimoto's thyroiditis accompanying pernicious anemia and subacute combined degeneration]

A 66-year old man presented to our hospital due to gait disturbance. He was unable to stand or walk without assistance. Laboratory tests revealed macrocytic anemia and an extremely low serum vitamin B₁₂ level. MRI showed high- intensity signals in the posterior and lateral column of the cervical and thoracic region of the spinal cord in T₂ weighted image. Other significant laboratory results were an increased and/or positive anti-thyroid peroxidase antibody, anti-gastric parietal cell antibody and anti-intrinsic factor antibody. He was diagnosed with a combination of Hashimoto's thyroiditis, pernicious anemia and subacute combined degeneration of the spinal cord (SCD). The patient's condition was autoimmune polyglandular syndrome type3B. The association of thyroid and gastric autoimmune disorders is a unique syndrome that tend to be complicated by vitamin B₁₂ deficiency.

Marked Hypergastrinemia with G-cell Hyperplasia in Two Autoimmune Gastritis Patients

Gastrin regulates gastric acid secretion, and gastrin secretion itself is regulated by the negative feedback system of gastric acidity. Autoimmune gastritis (AG) is a disease where parietal cells are destroyed, resulting in decreased acid production and an elevated serum gastrin level. We herein report 2 AG cases with marked hypergastrinemia (>5,000 pg/mL). In both cases, 24-hour gastric pH monitoring showed no time when gastric pH was <2, and immunohistochemistry revealed more than 140 gastrin-positive cells per linear millimeter at the antral mucosa. This is the first report to confirm the relationship between marked hypergastrinemia and G-cell hyperplasia with AG.

Primary hypophysitis and other autoimmune disorders of the sellar and suprasellar regions

The pituitary gland and the hypothalamus can be affected by autoimmune-mediated structural and functional disruption. These autoimmune-mediated diseases occur more commonly in females and are often found during pregnancy or in the post-partum period. Autoimmune diseases can either affect parts of the pituitary or hypothalamus, or can involve both sellar and suprasellar structures. Most of these cases comprise primary hypophysitis (PRH). Over the years, there has been a tremendous increase in the number of reported PRH cases and related disorders, including hypophysitis induced by immune checkpoint inhibitors. With this increasing data, more light is being shed on the spectrum of clinical presentations, biochemical and imaging abnormalities of these disorders. Regardless, these disorders are still relatively rare. The clinical presentation can vary vastly, based on the type of pituitary cell or the area of the suprasellar region affected. The severity can range from clinically silent disease to progressive and rapid deterioration and death, likely due to unrecognized central adrenal insufficiency. Although biopsy remains a gold standard for diagnosing these disorders, the current standard of practice is biochemical assessment for hormonal deficiencies and imaging studies. In several instances, these disorders spontaneously resolve, but medical or surgical intervention might be necessary to treat symptomatic disease. Due to the subtlety and a vast spectrum of clinical manifestations which could often be asymptomatic, and the rarity of the occurrence of these diseases in clinical practice, the diagnosis can be easily missed which could potentially lead to substantial morbidity or mortality. Therefore, it is crucial to have a strong clinical suspicion and pursue timely biochemical and imaging studies to initiate prompt treatment. In this article, we review the various autoimmune conditions that affect the sellar and suprasellar structures, their diagnostic approach and management of these disorders.

Gut microbiota and Hashimoto's thyroiditis

About two third of the human microbial commensal community, namely the gut microbiota, is hosted by the gastrointestinal tract which represents the largest interface of the organism to the external environment. This microbial community co-evolved in a symbiotic relationship with the human beings. Growing evidence support the notion that the microbiota plays a significant role in maintaining nutritional, metabolic and immunologic homeostasis in the host. Microbiota, beside the expected role in maintaining gastrointestinal homeostasis also exerts metabolic functions in nutrients digestion and absorption, detoxification and vitamins' synthesis. Intestinal microbiota is also key in the correct development of the lymphoid system, 70% of which resides at the intestinal level. Available studies, both in murine models and humans, have shown an altered ratio between the different phyla, which characterize a" normal" gut microbiota, in a number of different disorders including obesity, to which a significant part of the studies on intestinal microbiota has been addressed so far. These variations in gut microbiota composition, known as dysbiosis, has been also described in patients bearing intestinal autoimmune diseases as well as type 1 diabetes mellitus, systemic sclerosis and systemic lupus erythematosus. Being Hashimoto's thyroiditis the most frequent autoimmune disorder worldwide, the analysis of the reciprocal influence with intestinal microbiota gained interest. The whole thyroid peripheral homeostasis may be sensitive to microbiota changes but there is also evidence that the genesis and progression of autoimmune thyroid disorders may be significantly affected from a changing intestinal microbial composition or even from overt dysbiosis. In this brief review, we focused on the main features which characterize the reciprocal influence between microbiota and thyroid autoimmunity described in the most recent literature.

Statins, metformin, proprotein-convertase-subtilisin-kexin type-9 (PCSK9) inhibitors and sex hormones: Immunomodulatory properties?

The immune system is closely intertwined with the endocrine system. Many effects of medications used for various clinical endocrine conditions such as the metabolic syndrome, hypercholesterolemia, diabetes mellitus, hypertension, Graves' disease and others also have an impact on the immune system. Some drugs including statins, metformin, angiotensin converting enzyme and proprotein-convertase-subtilisin-kexin type-9 (PCSK9) inhibitors and sex hormones are known to have immunomodulatory properties. We here review the literature on this topic and provide some clinical examples including the use of statins in Graves' orbitopathy, rheumatoid arthritis, multiple sclerosis, and adult-onset Still's disease. In that context, we introduce a special immunodiagnostics method developed at the Institute of  Diabetes "Gerhardt Katsch" in Karlsburg, Germany, to not only measure but also monitor immune disease activity.

Black swans - neuroendocrine tumors of rare locations

Neuroendocrine neoplasms (NEN) are rare and heterogeneous. Therefore, they often remain unrecognized for many years, causing significant disease burden. We here report on four unusual NEN presentations including a metastatic NEN of the kidney, hypoglycemia caused by an insulin-like growth factor-2-oma (previously called non-islet-cell tumor hypoglycemia), multifocal pheochromocytoma in von Hippel Lindau syndrome, and ileal NEN metastatic to the heart. One could say that each one of these tumors were "black swans" and learning about them will increase further awareness of the spectrum of NEN.

Association of lymphocytic colitis and lactase deficiency in pediatric population

Characterized by colonic mucosa intraepithelial lymphocytosis, lymphocytic colitis is primarily an entity presented in the middle-aged to elderly patient population. Very few large series of lymphocytic colitis of childhood occurrence are available in the medical literature. Ten cases each of lymphocytic colitis and of colonic lymphocytosis of other diagnosis, all with duodenal disaccharidases analysis data, were collected from the files of our institution. The electronic medical records were reviewed and multiple variables were analyzed. The ten patients with lymphocytic colitis presented with diarrhea. Of these, three had abdominal pain. The age range was 2-18 years. Nearly all patients were Caucasian (90%) and 70% were female. Endoscopically, most had normal appearing colonic mucosa. Significant past medical history, family medical history and associated comorbidities included celiac disease, Down syndrome, juvenile arthritis and other autoimmune diseases. Interestingly, the most revealing observation was that the majority of cases (80%) were associated with lactase deficiency and, for the most part, gastrointestinal symptoms improved simply by treatment with Lactaid or avoidance of dairy products. This association is statistically significant. Our clinicopathological study indicates that the typical pediatric patient is a female Caucasian. A large of portion of the patients had associated lactase deficiency and improved on Lactaid supplement alone.

Expression of apoptosis-associated microRNAs in ethanol-induced acute gastric mucosal injury via JNK pathway

MicroRNAs (miRNAs) have been shown to be closely associated with cellular apoptosis, but their involvement in response to ethanol-induced gastric mucosal epithelial cell apoptosis remains largely unknown. The purpose of this study was to investigate the expression profile of apoptosis-associated miRNAs in ethanol-induced acute gastric mucosal injury and the mechanisms underlying injury. Gastric mucosal injury was induced in rats by oral administration of ethanol, and gastric tissues were collected for analysis of gastric ulcer index, apoptosis ratio, caspase-3 activity, and miRNAs expression. Cell cultures of human gastric mucosal epithelial cells (GES-1) were incubated with ethanol to induce apoptosis. Mimics or inhibitors of miRNAs or c-Jun N-terminal kinase (JNK) inhibitor were added to the cell culture medium. GES-1 cells were collected for analysis of apoptosis ratio, caspase-3 activity, miRNAs expression, and protein phosphorylation levels of JNK, p38 mitogen-activated protein kinase (p38MAPK), or extracellular signal-regulated kinase (ERK). In the animal experiments, gastric ulcer index, cellular apoptosis, and caspase-3 activity were significantly increased, accompanied by up-regulation of miR-145 and down-regulation of the microRNAs miR-17, miR-19a, miR-21, miR-181a, and miR-200c. In the human cell culture experiments, the anti-apoptotic effects of miR-19a and miR-21 or pro-apoptotic effect of miR-145 were confirmed by their corresponding mimics or inhibitor; the ethanol-induced GES-1 apoptosis as well as the changes in miRNAs expression were significantly attenuated in the presence of JNK inhibitor. These results demonstrated that miR-145, miR-19a, and miR-21 were the apoptosis-associated miRNAs in gastric mucosal epithelial cells. The regulation of expression of these 3 miRNAs in ethanol-induced GES-1 apoptosis involved the JNK pathway.

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

Introduction

Zollinger–Ellison syndrome is characterized by recurrent peptic ulcers and diarrhea that result from gastrin-secreting neuroendocrine tumors of the gastrointestinal tract; nevertheless, severe hypergastrinemia may also have alternative pathogenetic explanations.

Case presentation

A 61-year-old woman of Caucasian origin presented with a history of epigastric pain and early satiety, severe hypergastrinemia (approximately 2000 pg/mL) and a neuroendocrine polyp in the corpus of her stomach. Chronic atrophic gastritis and intestinal metaplasia was present, but she denied use of acid suppressant drugs and the results of tests for Helicobacter pylori as well as gastric parietal cell and intrinsic factor antibodies were negative. She underwent a radical gastric tangential resection. Six months later, serum gastrin was still elevated despite lack of recurrence of tumor.

Conclusion

The clinical picture was suggestive for a hypochlorhydria-related hypergastrinemia with subsequent development of a non-secreting carcinoid. We suggest a periodic endoscopic follow-up in patients with severe hypochlorhydria-related hypergastrinemia in order to earlier detect neuroendocrine polyps.

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

Data on coexisting Graves' disease (GD), hypoparathyroidism, and systemic lupus erythematosus (SLE) are limited. The thyroid and parathyroid glands may be extra sensitive to irradiation damage in an underlying autoimmune condition. A 34-year-old black woman presented with tetanic-like cramps, easy skin bruising, fatigue, weight gain, nocturia and back pain. She was previously diagnosed with GD in 2001 and underwent radioiodine therapy (RAI) in 9/01 using 6 mCi. PostRAI (November 2001) she developed hypocalcemia and hypothyroidism (2/02). In 2007, SLE was diagnosed. In October 2009, s-calcium and PTH were still low at 7.1 mg/dl and 9 pg/mL, respectively, although the patient denied symptoms on vitamin D and calcium supplementation. To identify possible autoimmune damage of the parathyroids, we evaluated the presence of activating antibodies to the CaSR and also analyzed the DNA sequence of all 6 translated exons and flanking intronic sequences of her CaSR gene for a functionally significant CaSR mutation but neither was positive. The initial autoimmune damage to her thyroid and possibly parathyroid glands followed by irradiation of them seems to have contributed to her developing both hypoparathyroidism (11/01) and hypothyroidism (2002). The patient could potentially have had parathyroid autoantibodies in 2001 that disappeared by 2009 when she was tested for them. We consider that the multiple autoimmune conditions developed over the past decade of her life with the concurrent irradiation contributing to her brittle hypoparathyroidism. Select patients with GD and perhaps parathyroid autoantibodies with a slowly developing destructive impact on the parathyroid glands may then develop overt hyoparathyroidism with rather low dose RAI ablation. This patient adds to the evolving spectrum of polyglandular syndrome variants.