Neuroendocrine tumor markers and enterochromaffin-like cell hyper/dysplasia in type 1 diabetes

Role and function of granin proteins in diabetes mellitus

The granin glycoprotein family consists of nine acidic proteins; chromogranin A (CgA), chromogranin B (CgB), and secretogranin II–VIII. They are produced by a wide range of neuronal, neuroendocrine, and endocrine cells throughout the human body. Their major intracellular function is to sort peptides and proteins into secretory granules, but their cleavage products also take part in the extracellular regulation of diverse biological processes. The contribution of granins to carbohydrate metabolism and diabetes mellitus is a recent research area. CgA is associated with glucose homeostasis and the progression of type 1 diabetes. WE-14, CgA_10-19, and CgA_43-52 are peptide derivates of CgA, and act as CD4⁺ or CD8⁺ autoantigens in type 1 diabetes, whereas pancreastatin (PST) and catestatin have regulatory effects in carbohydrate metabolism. Furthermore, PST is related to gestational and type 2 diabetes. CgB has a crucial role in physiological insulin secretion. Secretogranins II and III have angiogenic activity in diabetic retinopathy (DR), and are novel targets in recent DR studies. Ongoing studies are beginning to investigate the potential use of granin derivatives as drugs to treat diabetes based on the divergent relationships between granins and different types of diabetes.

Chromogranin Serves as Novel Biomarker of Endocrine and Gastric Autoimmunity

CONTEXT

The glycoprotein chromogranin A (CgA) is expressed by endocrine and neuroendocrine cells. High levels of serum CgA serve as markers of neuroendocrine tumors (NET), but its role in autoimmunity has not been assessed.

OBJECTIVE

To investigate CgA utility as a marker of endocrine autoimmunity.

METHODS

CgA serum levels were evaluated in 807 consecutive unselected participants (cross-sectional study) with the time-resolved amplified cryptate emission technology.

RESULTS

Serum CgA concentrations were increased in 66%, 39%, 38%, and 24% of patients with NET, type 1 diabetes (T1D), autoimmune gastritis (AG) and autoimmune polyendocrinopathy (AP), respectively. Compared with healthy participant controls (C), the odds of positive CgA measurement were up to 28 times higher in the disease groups. In detail, the odds ratios (ORs) for positive CgA levels were 27.98, 15.22, 7.32 (all P < 0.0001) and 3.89 (P = 0.0073) in patients with NET, T1D, AG, and AP, respectively. In AG, CgA and serum gastrin correlated positively (r = 0.55; P < 0.0001). The area under the receiver operating characteristic curve to predict AG was higher for parietal cell antibody (PCA) positivity than for CgA (0.84 vs 0.67; P < 0.0001). However, in combination with PCA and intrinsic factor autoantibodies, CgA independently improved prediction of AG (OR 6.5; P = 0.031). An impact of age on CgA positivity and on CgA value was detected (P < 0.0001) while current smoking significantly increased CgA serum levels by 25% (P = 0.0080).

CONCLUSION

CgA qualifies as a novel biomarker for T1D, AP, and AG.

Serum chromogranin A level continuously rises with the progression of type 1 diabetes, and indicates the presence of both enterochromaffin-like cell hyperplasia and autoimmune gastritis

AIMS/INTRODUCTION

The relationship of chromogranin A (CgA) levels above the normal range with various outcomes, such as glycated hemoglobin levels, enterochromaffin-like cell hyperplasia and autoimmune gastritis, was investigated in type 1 diabetes patients with special regard to the progression of comorbidities.

MATERIALS AND METHODS

A cohort study on 153 type 1 diabetes patients was carried out with a prospective branch on clinical and laboratory data, and a retrospective branch on histological data obtained by gastroscopy.

RESULTS

Patients with CgA levels above the upper limit of the normal range (n = 28) had significantly higher glycated hemoglobin levels (P = 0.0160) than those with CgA in the normal range (n = 125). The correlation between CgA and glycated hemoglobin was significant (P < 0.0001), but weak (R = +0.32). A slight, but steady elevation (P = 0.0410) in CgA level was observed to co-vary with the duration of type 1 diabetes. Enterochromaffin-like cell hyperplasia and autoimmune gastritis was significantly more frequent (P = 0.0087 for both) in the high CgA group. Detailed analyses on gastric tissue samples confirmed a progression of enterochromaffin-like cell hyperplasia (P = 0.0192) accompanied by CgA elevation (P = 0.0316).

CONCLUSIONS

The early detection and follow up of the later progression of enterochromaffin-like cell hyperplasia and autoimmune gastritis into gastric neuroendocrine tumors, which have ~100-fold greater incidence in type 1 diabetes patients, can be achieved by assessment of CgA levels. Therefore, the use of CgA could be considered as a novel auxiliary biomarker in the care of these type 1 diabetes complications.

Comparison between Two Methods in the Determination of Circulating Chromogranin A in Neuroendocrine Tumors (NETs): Results of a Prospective Multicenter Observational Study

Several methods for analyzing CgA using either monoclonal or polyclonal antibodies have been developed, which differ in their diagnostic performance. The present paper describes the results of a prospective multicenter study aimed at comparing the clinical value of the two most widely used commercially available CgA assay kits in patients affected by neuroendocrine tumors (NETs). Two hundred sixty-one patients from 40 different centers and 99 healthy subjects were evaluated. CgA levels were measured with two different methods, a two-step immunoradiometric assay (IRMA) and an enzyme-linked immunosorbent assay (ELISA). CgA was measured centrally by two reference laboratories, one of which used IRMA and the other ELISA, and it was measured by the participating institutions with the method routinely used by each of them. The major findings of the present study were: (i) the two assays for the determination of CgA present good diagnostic performance; (ii) both assays are robust and guarantee comparable results when applied in different settings (central vs local laboratory); (iii) the negative/positive cutoff points (87 ng/mL for IRMA and 21.3 U/L for ELISA) were established according to standardized criteria; (iv) the results obtained with the two assays in basal clinical samples of patients affected by NETs show an apparently satisfactory correlation (rs=0.843, p<0.0001). However, a possibly clinically meaningful 36% discordance rate was found. These findings support the hypothesis that the two CgA kits might provide partially different information.

[The role of chromogranin-A and its derived peptide, WE-14 in the development of type 1 diabetes mellitus]

Chromogranin-A is a member of the granine protein family. It is produced in neuroendocrine cells via secretory granules. Many cleavage proteins are formed from chromogranin-A, from which some have well known biological activity, while the function of others is not yet fully known. Serum chromogranin-A levels are used in neuroendocrine tumour diagnostics. Recent studies showed that one of its cleavage protein, WE-14 may also play a role in the development of type 1 diabetes. WE-14 may function as an autoantigen for T-cells involved in the destruction of β-cells. This mechanism was previously observed only in non-obese diabetic mice. Novel results show that WE-14 also serves as a target for autoreactive cells in newly diagnosed type 1 diabetic patients as well, which reaction can be increased with transglutaminase. In this paper the authors summarize the recent knowledge about chromogranin-A and its potential role in the pathomechanism of type 1 diabetes mellitus.

Anaemia, a common but often unrecognized risk in diabetic patients: a review

Anaemia in patients with diabetes, both type 1 and type 2, is a frequent clinical finding. The mechanisms of anaemia are multifactorial and often not very well understood. Iatrogenic causes, including oral antidiabetic drugs, ACE inhibitors and ARBs, and renal insufficiency are the major causes of anaemia in patients with type 2 diabetes. In patients with type 1, the cause is often an associated autoimmune disease, and screening for autoimmune gastritis, pernicious anaemia, Hashimoto's thyroiditis, coeliac disease and Addison's disease is recommended. Other rare causes - including G6PD deficiency, microangiopathic haemolytic anaemia and thiamine-responsive megaloblastic anaemia - should be suspected in young patients or when the classical causes are excluded. Early detection and recognition of the cause(s) of anaemia in patients with diabetes could help to prevent other clinical manifestations as well as the complications of diabetes.

Predictive value of gastrin levels for the diagnosis of gastric enterochromaffin-like cell hyperplasia in patients with Hashimoto's thyroiditis

AIM

Gastrin and chromogranin A (CgA) levels have been tested for the diagnosis of enterochromaffin-like cell hyperplasia (ECLH) in patients with type 1 diabetes and autoimmune atrophic gastritis but not for patients with Hashimoto's thyroiditis (HT). The aim of the study was to develop receiver operating characteristic (ROC) curves for gastrin and CgA levels and other clinical and biochemical parameters, as means for pretest probability of gastric ECLH in patients with HT.

METHODS

A total of 115 patients with HT were prospectively studied for a median period of 4 (2-7) years. Gastrin, CgA, vitamin B12, anti-parietal cell antibodies, free thyroxine, thyrotropin, and neuron-specific enolase levels were measured. Their predictive values were calculated according to the histological findings for ECLH diagnosis from esophagogastroduodenoscopy-obtained biopsies.

RESULTS

Thirteen patients (11.3%) had ECLH. The areas under the curve for gastrin and CgA level were 0.898 (p < 0.001) and 0.853 (p < 0.001), respectively. The product sensitivity × specificity was 0.803 and 0.653 for gastrin and CgA levels >89.5 and >89.1 ng/ml, respectively. Two and 4 patients with ECLH had normal gastrin and CgA levels, respectively. The most specific combined parameters predicting ECLH were gastrin >89.5 ng/ml with concomitant low B12 levels (96.1% specificity).

CONCLUSION

Gastrin levels have high diagnostic accuracy for ECLH identification in patients with HT, and are highly specific when combined with low B12 levels. However, they should be interpreted with caution, as some patients may harbor gastric ECLH even if gastrin levels are not increased, necessitating further follow-up.

Serum autoimmune gastritis markers, pepsinogen I and parietal cell antibodies, in patients with type 1 diabetes mellitus: a 5-year prospective study

BACKGROUND AND AIM

To determine the temporal evolution of serum markers of autoimmune gastritis, mainly pepsinogen I (PI) and parietal cell antibodies (PCA), in patients with Type 1 diabetes mellitus (DM1).

MATERIALS AND METHODS

A 5-yr prospective follow-up study of 168 DM1 patients (87 men, aged 31 ± 9.3 yr) attending the endocrinology outpatient clinic of a university hospital evaluated in 2001 and 2006. Serum PI, gastrin, hemoglobin, cobalamin concentrations, PCA and antibodies to intrinsic factor were measured.

RESULTS

In 2001, 11 patients had low PI concentrations and positive PCA (group I), 11 had only low PI concentrations (group II), and 33 had only positive PCA (group III). After 5 yr, PI remained low and PCA positive in all patients from group I. In group II, PI remained low in 4 and normalized in 7. In group III, 4 patients presented low PI concentrations after 5 yr, which remained normal in the other 29 subjects. PCA became negative in 17 patients from group III. In 2001, 3 of the 11 patients of group I had low cobalamin concentrations. In 2006, 2 additional patients from this group presented low cobalamin concentrations.

CONCLUSIONS

These results show the importance of determining PI together with PCA, since the presence of abnormal results in both tests, that is low PI and positive PCA, is the association that best identifies patients with a higher risk to decrease cobalamin concentrations during follow-up.

Unexplained refractory iron-deficiency anaemia in a 41-year-old woman

The clinical and instrumental findings revealed a case of autoimmune polyendocrine syndrome (APS) type 3B+C in a 41-year-old Caucasian woman with unexplained refractory iron-deficiency anaemia secondary to autoimmune atrophic gastritis and a long-term history of two different autoimmune diseases-Hashimoto's disease and vitiligo. Indeed the occurrence in the same patient of three or more autoimmune diseases defines APS. The first classification of APS was suggested by Neufeld and Blizzard in 1980 and it included four main types of APS on the basis of clinical features. The only case of APS type 3B+C was described by Amerio et al in 2006.

Chromogranin A as a useful neuroendocrine marker in patients with autoimmune Addison's disease

BACKGROUND

Antiparietal cells antibodies (APC-Ab) are commonly found in patients with autoimmune Addison's disease (AAD), usually pointing to autoimmune atrophic gastritis and pernicious anemia. The autoaggression to the gastric proton pumpmay result in a long-term hypergastrinemia, which predisposes to enterochromaffin-like cell hyper/dysplasia and gastric carcinoids.

AIM

We evaluated the clinical utility of assessing serum chromogranin A levels in patients with AAD.

MATERIAL AND METHODS

Serum chromogranin A, gastrin, and gastric APC-Ab levels were determined in 40 patients with AAD using commercially available kits.

RESULTS

Serum chromogranin A and gastrin levels were found to be elevated in 27.5 and 22.5% of patients with AAD, respectively. The Addison's patients with elevated APC-Ab had significantly higher chromogranin A and gastrin levels, as compared to individuals with normal APC-Ab (chromogranin A: 128.00+/-123.08 vs 57.68+/-36.50 ng/ml, p=0.0036; gastrin: 141.38+/-191.43 vs 49.50+/-75.36 muU/ml, p=0.003). Additionally, the patients with AAD and coexisting elevated serum APC-Ab, contrary to those with normal levels, showed a significant correlation between the chromogranin A and gastrin concentrations (r=0.52, p=0.0092 vs r=0.211, p=0.43). Serum chromogranin A appeared also significantly correlated with APC-Ab levels (r=0.431, p=0.005).

CONCLUSIONS

In patients with autoimmune Addison's disease hyperchromograninemia and hypergastrinemia occur with a prevalence of 27.5 and 22.5%, respectively. Addison's patients with coexisting elevated gastric APC-Ab, particularly with elevated gastrin levels, are at risk of enterochromaffin-like cells hyper/dysplasia. Serum chromogranin A assessment may complement histology for the early diagnosis of gastric carcinoid in these patients.

Automated recognition and counting of the immunoreactive neuroendocrine cells in chronic gastritis (the preliminary study)

The paper presents the designed software CAMI (Computerized Analysis of Microscopic Images) for a digital reconstruction of the diversiform glands seen in chronic inflammatory gastric mucosa, and for automated recognition and quantization of the immunoreactive neuroendocrine (NE) cells appearing within mucosal glands. Digital reconstruction of the individual gastric gland is difficult due to variable shapes of the glandular cross-sections. Fifteen gastric biopsy specimens representing chronic gastritis were stained routinely with H+E and immunohistochemically with 3 NE markers: Chromogranin A, Somatostatin and Serotonin. Two expert pathologists counted manually the NE cells with the light microscope in 4 types of glandular cross-sections: round, short- oblique, long- oblique and longitudinal. The automated counting of the NE cells was performed on the digital images presenting the same microscopic areas which were selected for the manual reading. The first step of image analysis was concerned to the cell extraction and recognition of the cytoplasmic immunoreactivity. The unstained nuclei of the NE cells were spotted by the sequential thresholding algorithm combined with the artificial neural network of Support\Vector Machine (SVM) type. The second step of image analysis comprised reconstruction of the glands. The presumed shape of each gastric gland was defined by the cellular lining of viewed glandular cross-section. The designed algorithm for gland reconstruction was based on the cell masks. The third step of analysis dealt the cell counting. Every recognized gland with the face cells was used for the NE cell evaluation. The results of the automated quantization compared with manual counting results for the number of NE cells showed high concordance in 3 types of glandular cross-sections: round, short- and long- oblique. A difference noticed in the results of the longitudinal glands should be verified in the extended study. The designed software CAMI is more adequate for the gland recognition with an discontinuous gland face seen in the immunohistochemical digital images, which appear to be a difficult problem for the accurate automated analysis of the cellular component of glands.

Risk factors associated with neuroendocrine tumors: A U.S.-based case-control study

Carcinoids are rare neuroendocrine tumors (NETs); however, their incidence has significantly increased in the United States over the past 30 years. Little is known about the epidemiology of these cancers and their associated risk factors. We evaluated the independent effects of multiple risk factors associated with NETs arising at 5 disease sites (small intestine, stomach, lung, pancreas and rectum). We conducted a retrospective, hospital-based, case-control study involving 740 patients with histologically confirmed NETs and 924 healthy controls. Information on different risk factors was collected, and unconditional logistic regression analysis was used to determine adjusted odds ratios (AORs) and 95% confidence interval (CI) by the maximum-likelihood method. Smoking and alcohol consumption were not associated with NETs development in either men or women. However, a family history of cancer was a significant risk factor for all NETs. A long-term history of diabetes mellitus was a significant risk factor for gastric NETs (AOR = 5.6; 95% CI, 2.1-14.5), particularly in women (AOR = 8.4; 95% CI, 1.9-38.1). Diabetes modified the risk among women with a positive family history of cancer for the development of gastric NETs (AOR = 52.2; 95% CI, 5.5-491.5). Our results suggest that the risk of NETs may mostly explained by genetic factors. The increased risk of gastric NETs in women with both diabetes and a positive family history of cancer suggest that women may have a greater genetic susceptibility to NETs than men.

Autoimmune gastritis in type 1 diabetes: a clinically oriented review

CONTEXT

Autoimmune gastritis and pernicious anemia are common autoimmune disorders, being present in up to 2% of the general population. In patients with type 1 diabetes or autoimmune thyroid disease, the prevalence is 3- to 5-fold increased. This review addresses the epidemiology, pathogenesis, diagnosis, clinical consequences, and management of autoimmune gastritis in type 1 diabetic patients.

SYNTHESIS

Autoimmune gastritis is characterized by: 1) atrophy of the corpus and fundus; 2) autoantibodies to the parietal cell and to intrinsic factor; 3) achlorhydria; 4) iron deficiency anemia; 5) hypergastrinemia; 6) pernicious anemia may result from vitamin B12 deficiency; and 7) in up to 10% of patients, autoimmune gastritis may predispose to gastric carcinoid tumors or adenocarcinomas. This provides a strong rationale for screening, early diagnosis, and treatment. The management of patients with autoimmune gastritis implies yearly determination of gastrin, iron, vitamin B12 levels, and a complete blood count. Iron or vitamin B12 should be supplemented in patients with iron deficiency or pernicious anemia. Whether regular gastroscopic surveillance, including biopsies, is needed in patients with autoimmune gastritis/pernicious anemia is controversial. The gastric carcinoids that occur in these patients generally do not pose a great threat to life, whereas the danger of developing carcinoma is controversial. Nevertheless, awaiting a consensus statement, we suggest performing gastroscopy and biopsy at least once in patients with autoantibodies to the parietal cell, iron-, or vitamin B12-deficiency anemia, or high gastrin levels.

CONCLUSION

The high prevalence of autoimmune gastritis in type 1 diabetic patients and its possible adverse impact on the health of the patient provide a strong rationale for screening, early diagnosis, periodic surveillance by gastroscopy, and treatment.

Development of silent gastric carcinoid in a type 1 diabetic patient with primer hypothyreosis

Az 1-es típusú cukorbetegség gyakran társul egyéb autoimmun kórképekkel. A parietalis sejtellenes antitestek (PCA), melyek az 1-es típusú cukorbetegek mintegy 20%-ában megtalálhatók, autoimmun gastritis és anaemia perniciosa jelenlétére figyelmeztetnek. A PCA-k a gyomor-H + /K + ATP-ázt károsítják, és hypo-/achlorhydriát, hypergastrinaemiát okozhatnak. Ennek következtében az enterochromaffin-szerű (ECL) sejtek hyper-/dysplasiaja alakulhat ki, mely carcinoid gyomortumor kialakulására hajlamosít. Az ECL-sejtek hyperplasiájából fejlődő gyomorcarcinoidok az autoimmun gastritises vagy anaemia perniciosában szenvedő betegek 4–9%-ában alakulnak ki. A 29 éves, 6 éve 1-es típusú diabéteszben szenvedő, 8 éves kora óta primer hypothyreosis miatt pajzsmirigyhormon-szubsztitúcióban részesülő nőbetegünknél gyomorpanaszok miatt felső panendoszkópia és biopsziás vizsgálat történt. Az endoszkópia többszörös kicsi polipokat mutatott a fundus területén nonantral hypergastrinaemiás (A-típusú) atrophiás gastritissel. A parietalis sejtantitest-vizsgálat pozitív volt, a szérum-chromogranin-A koncentrációja (CgA) 289,7 ng/ml (norm: 98 ng/ml alatt), a TSH-szint 9,93 mIU/L volt. A szövettani vizsgálat carcinoid tumort igazolt. Octreotidterápiát követően parciális gastrectomiát végeztek. Műtét után a szérum-chromogranin-A-szint normalizálódott. A nonatral, többszörös polipok néma neuroendocrin tumort takarhatnak, melyek rendszerint lassan növekvő, benignus viselkedésű endokrin daganatok, de magas malignitású endokrin karcinómák is lehetnek. A specifikus szérum- vagy szöveti chromogranin-A (CgA) és egyéb endokrin tumorra utaló markerek mérésének elérhetővé válásával e tumorok könnyen felismerhetők lehetnek a klinikus számára.

Plasma chromogranin A in patients with autoimmune chronic atrophic gastritis, enterochromaffin-like cell lesions and gastric carcinoids

OBJECTIVE

In atrophic body gastritis (ABG) chronic hypergastrinaemia stimulates enterochromaffin-like (ECL) cell proliferation with development of cell hyperplasia, dysplasia and possibly type-1 gastric carcinoids. As circulating chromogranin A (CgA) levels are a marker of neuroendocrine tumours, we evaluated the clinical usefulness of CgA assay in ABG patients to detect those with carcinoids.

DESIGN AND METHODS

Plasma CgA levels were measured using a commercial ELISA in 45 healthy volunteers, nine patients with type-1 gastric carcinoids and 43 consecutive ABG patients (21 without and 22 with ECL cell hyperplasia/dysplasia).

RESULTS

CgA levels were significantly higher in ABG patients with and without gastric carcinoids than in healthy subjects (P < 0.001). The highest values occurred in patients with carcinoids (median (interquartile range): 58.1 (44.5-65.3) U/l) and with ECL cell hyperplasia/dysplasia (35.5 (31.8-48.65) U/l) but there were no significant differences in CgA among the various subgroups of ABG patients classified according to ECL cell status. Nevertheless, in ABG patients without carcinoids CgA values correlated with the presence and severity of ECL cell lesions (r(s) = 0.428, P < 0.01). The sensitivity and specificity of the CgA assay in identifying patients with carcinoids were 100 and 23% respectively.

CONCLUSIONS

CgA plasma levels reflect the histological degree of ECL cell lesions in patients with ABG but the assay specificity is too low to detect among these patients those with gastric carcinoids.