Thyroid and gastric autoimmunity in patients with diabetes mellitus

100 years of insulin: celebrating the past, present and future of diabetes therapy

The year 2021 marks the centennial of Banting and Best's landmark description of the discovery of insulin. This discovery and insulin's rapid clinical deployment effectively transformed type 1 diabetes from a fatal diagnosis into a medically manageable chronic condition. In this Review, we describe key accomplishments leading to and building on this momentous occasion in medical history, including advancements in our understanding of the role of insulin in diabetes pathophysiology, the molecular characterization of insulin and the clinical use of insulin. Achievements are also viewed through the lens of patients impacted by insulin therapy and the evolution of insulin pharmacokinetics and delivery over the past 100 years. Finally, we reflect on the future of insulin therapy and diabetes treatment, as well as challenges to be addressed moving forward, so that the full potential of this transformative discovery may be realized.

Deficiency of micronutrients in patients affected by chronic atrophic autoimmune gastritis: A single-institution observational study

BACKGROUND

Chronic atrophic autoimmune gastritis (CAAG) leads to vitamin B₁₂ deficiency, but other micronutrient deficiencies are largely understudied.

AIMS

To investigate the prevalence of micronutrient deficiencies in CAAG patients and their potential relationship with the grading of gastric atrophy or entero-chromaffin-like cells hyperplasia or body mass index (BMI).

METHODS

From 2005 to 2016 a number of CAAG patients underwent regular follow-up with annual blood testing and upper gastrointestinal tract endoscopy every years.

RESULTS

Out of the 122 CAAG patients checked (100 F; median age 65 years), 76 presented nutritional deficiencies, single in 24 and multiple in 52 cases: a deficiency of B₁₂ and iron showed in 42 patients, 25-OH vitamin D lacked in 76 and folic acid in 6 cases. 25-OH vitamin D levels directly correlated with B₁₂ levels and were significantly lower in patients with macronodular than in those with linear or micronodular hyperplasia. No significant correlation was observed between B₁₂, folic acid or ferritin levels and BMI, blood gastrin levels, the grading of gastric atrophy or ECL cells hyperplasia.

CONCLUSIONS

25-OH vitamin D deficiency was the main one in CAAG patients: its correlation with B₁₂ deficiency may indicate underlying shared pathogenic mechanisms, although further studies are needed to confirm this hypothesis.

Association of autoimmune thyroid diseases, chronic atrophic gastritis and gastric carcinoid: experience from a single institution

PURPOSE

Autoimmune polyendocrine syndromes (APS) type III are characterized by the association of autoimmune thyroid disease (ATD) with other autoimmune diseases such as diabetes, alopecia, pernicious anemia, vitiligo and chronic atrophic gastritis. A strong association between ATD and atrophic gastritis (AG) has been demonstrated. Moreover 10 % of patients affected by AG have a predisposition to develop gastric carcinoid and adenocarcinoma as a result of chronic hypergastrinemia caused by achlorhydria and subsequent ELC cells neoplastic transformation.

METHODS

The aim of the study is to evaluate, in a consecutive series of patients followed for ATD in our outpatients clinic, the prevalence of AG. In the period 2004-2014, 242 patients with ATD underwent a screening performing APCA, Vitamin B12, ferritin, iron, and hemoglobin and red cells count measurements with subsequent gastroscopy in case of APCA positivity.

RESULTS

We found 57/242 (23.5 %) patients with APCA positivity. Of these patients 33/57 (57.8 %), 31 F and 2 M, were affected by Graves disease; 24/57 (42.1 %) 21 F and 3 M by Hashimoto thyroiditis; 10/57 (17.5 %) presented with anemia, 14/57 (24.5 %) with vitamin B12 deficiency, 9/57 (15.7 %) with iron deficiency. In 2/57 a gastric carcinoid was found.

CONCLUSIONS

Our data confirm the high association rate of AG in ATD which frequently is not an isolated disease but configure the picture of APS type III and need to be followed accordingly. An early diagnosis may be useful for diagnosis of gastric carcinoids and to explain and treat a gastric related L-thyroxine malabsorption and presence of chronic unexplained anemia.

Italian Association of Clinical Endocrinologists (AME) & Italian Association of Clinical Diabetologists (AMD) Position Statement : Diabetes mellitus and thyroid disorders: recommendations for clinical practice

Thyroid disease and diabetes mellitus, the most common disorders in endocrine practice, are not infrequently associated in the same subject. An altered thyroid function may affect glucose tolerance and worsen metabolic control in patients with diabetes. Thyrotoxicosis increases the risk of hyperglycemic emergencies, while a clinically relevant hypothyroidism may have a detrimental effect on glycemic control in diabetic patients. The association of alterations in thyroid function with diabetes mellitus may adversely affect the risk of cardiovascular and microvascular complications resulting from diabetes. Moreover, the treatments used for both diabetes and thyroid disease, respectively, can impact one other. Finally, multinodular goiter, but not thyroid carcinoma, was shown to be more prevalent in type 2 diabetes mellitus. Aim of the present Position Statement is to focus on the evidence concerning the association of thyroid disease and diabetes mellitus and to provide some practical suggestions for an updated clinical management.

Autoimmune gastritis mediated by CD4+ T cells promotes the development of gastric cancer

Chronic inflammation is a major risk factor for cancer, including gastric cancers and other gastrointestinal cancers. For example, chronic inflammation caused by autoimmune gastritis (AIG) is associated with an increased risk of gastric polyps, gastric carcinoid tumors, and possibly adenocarcinomas. In this study, we characterized the progression of gastric cancer in a novel mouse model of AIG. In this model, disease was caused by CD4(+) T cells expressing a transgenic T-cell receptor specific for a peptide from the H(+)/K(+) ATPase proton pump, a protein expressed by parietal cells in the stomach. AIG caused epithelial cell aberrations that mimicked most of those seen in progression of human gastric cancers, including chronic gastritis followed by oxyntic atrophy, mucous neck cell hyperplasia, spasmolytic polypeptide-expressing metaplasia, dysplasia, and ultimately gastric intraepithelial neoplasias. Our work provides the first direct evidence that AIG supports the development of gastric neoplasia and provides a useful model to study how inflammation drives gastric cancer.

Do children and adolescents with type 1 diabetes mellitus have a higher frequency of parietal cell antibodies than healthy controls?

OBJECTIVES

Parietal cell antibodies (PCA) are markers of autoimmune gastritis (AG). AG can lead to hypergastrinemia and iron-deficiency anaemia (IDA). Compared to healthy controls, adults with type 1 diabetes mellitus (T1DM) show a higher prevalence of PCA (1% vs 20%). The aim of the present study was to evaluate the frequency of PCA in children and adolescents with T1DM compared to healthy controls and the clinical and biochemical markers.

PATIENTS AND METHODS

We studied 170 patients (87 boys) with T1DM (mean age 12.9 years) and 101 healthy controls (49 boys; mean age 13.0 years). PCA, free T4, free T3, thyroid-stimulating hormone (TSH), and thyroid antibodies were measured in all of the patients. In addition, gastrin, pepsinogen I, iron, ferritin, vitamin B12, and folate were measured in patients with T1DM only. Gastroscopy was carried out in patients with T1DM having high (>100 U/mL) PCA levels.

RESULTS

The frequency of PCA in patients with T1DM was 5.29% compared to 1.98% in healthy controls (not significant). PCA was strongly correlated to both thyroid peroxidase antibodies (TPOAb) and gastrin levels (P = 0.001). IDA was present in 4 of 9 patients from the PCA-positive group compared to 4 of 160 patients from the PCA-negative group. Hypergastrinemia was found in 2 PCA-positive patients. Histopathologically, 1 of 4 patients showed early symptoms of AG.

CONCLUSIONS

Children and adolescents with T1DM have a lower frequency of PCA than is reported for adults. Compared to healthy controls, they seem to be at increased risk for developing PCA, in particular if positive for TPOAb, but overt clinical disease is rare in children with T1DM.

[Prevalence and predictive factors of parietal cell antibody positivity in autoimmune thyroid disease]

BACKGROUND AND OBJECTIVES

Our aim was to evaluate the prevalence of parietal cell antibodies (PCA) in patients with autoimmune thyroid disease (ATD).

MATERIAL AND METHODS

We performed a descriptive, cross-sectional study of patients with ATD. The presence of PCA was determined. Elevated antithyroid antibodies (ATAs) were defined as those higher than the 75th percentile of distribution. Multivariate logistic regression models were built to assess the independent contribution of the following variables to PCA positivity: age, sex, hemoglobin, medium corpuscular volume (MCV), dose/Kg of levothyroxine (LT4), disease duration and elevated ATA levels.

RESULTS

A total of 148 patients were included (137 females). The mean age was 45.7 (SD 15) years and disease duration was 4.5 (SD 4) years. Forty-three patients (29%) with Graves' disease and 105 (71%) with primary hypothyroidism were included. The 75th percentile of distribution was 420U/ml for anti-peroxidase antibodies and 200U/ml for anti-thyroglobulin antibodies. PCA positivity was found in 30 patients, with an overall prevalence of 20.3%. PCA positivity with titers higher than 1/640 was found in 19 patients (12.8%). The only independent predictive factor of PCA positivity was the presence of elevated levels of ATAs (odds ratio (OR)=3; 95% confidence interval (CI): 1.1-8.6; p=0.04). The only independent predictive factor of PCA positivity at titers >/=1/640 was also the presence of elevated levels of ATAS (OR=7.3; 95% CI: 1.6-32.7; p=0.009).

CONCLUSIONS

The prevalence of PCA positivity in patients with ATD was 20%. Elevated levels of ATAs increase the risk of PCA positivity.

Autoimmune Gastritis: Historical Antecedents, Outstanding Discoveries, and Unresolved Problems

The earliest recorded history of autoimmune gastritis can be traced to 1849 in London, when Thomas Addison described "a very remarkable form of anemia" later called pernicious (fatal) anemia (PA). This was followed by the recognition of a gastric mucosal defect suspected to have a nutritional basis, the discovery of the megaloblast that characterized the anemia, the insufficiency of a dietary extrinsic factor characterized as vitamin B12 (cobalamin), and a gastric-secreted intrinsic factor. Treatment with vitamin B12 proved curative. The link between PA and gastritis and atrophy was first confirmed histologically after immediate fixation of the stomach postmortem and later, in the 1940s, by peroral tube biopsy. The causes of gastritis remained enigmatic until the era of autoimmunity, when autoantibodies were detected first to gastric intrinsic factor and then to gastric parietal cells. Hints of a dichotomy in pathogenesis of gastritis were crystallized by the description in 1973 of Type A (Autoimmune) and Type B (later, Bacterial) gastritis. Clarification was enhanced by identification in Type A gastritis of the autoantigen of the parietal cell antibody, by the alpha and beta subunits of gastric H+/K+ ATPase, and by the highly informative experimental murine model of postneonatal thymectomy autoimmune gastritis, and in Type B of the causative role of gastric infection with Helicobacter pylori (H. pylori). A denouement will require a full understanding of (1) the origin and pathogenetic contribution of antibody to intrinsic factor; (2) the connection, if any, between H. pylori infection and Type A autoimmune gastritis; and (3) the genetic contributions to gastritis, whether due to autoimmunity or to H. pylori infection.

Speculations on potential anti-receptor autoimmune diseases

Many autoimmune disorders have a strong tendency to cluster in a single patient or type of patient. Therefore, in those cases in which anti-receptor antibodies are known to be responsible for one of the diseases in the cluster, it is logical to proceed investigatively on the presumption that the aetiology of other members of the cluster may also have an anti-receptor autoantibody basis. This logic is examined by considering examples of clustering in human diseases involving both organ-specific and non-organ-specific autoimmunities. The strong relationship between clustering among autoimmune diseases and the HLA-B8/DRw3 haplotype may provide a marker for anti-receptor autoimmune diseases.

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.

Autoimmune thyroid disease in Indian children with type 1 diabetes mellitus

The objective of the present study was to determine the prevalence of autoimmune thyroid disease in Indian children with type 1 diabetes mellitus by the assay of antibodies to thyroid peroxidase and thyroglobulin. The study population consisted of 35 children with type 1 diabetes mellitus and 32 healthy age- and sex-matched control children. Thyroid peroxidase antibodies (TPO) were determined by ELISA and thyroglobulin antibodies (TGA) by passive hemagglutination. Thyroid function tests and tests of glycemic control were also performed. These assays were repeated after six months and one year. TPO were observed in 19 (54.3%) patients compared to three (10%) controls, and TGA in 11 (31.4%) patients and none of the controls. Both these observations were statistically significant with p=0.0002 for TPO and 0.0016 for TGA. The prevalence of these antibodies was not different in boys and girls and did not change with the duration of diabetes. All patients who were positive for TGA were also positive for TPO. Thyroid function tests were abnormal in one patient who was found to have Hashimoto's thyroiditis. There is a definite need to screen all diabetic children for thyroid antibodies and carefully follow up those patients in whom these antibodies are positive.

The discovery of type 1 diabetes

The etiological heterogeneity of idiopathic diabetes has been recognized for 25 years, and subdivision into type 1 and type 2 diabetes is fundamental to the way we think about the disease. Review of the literature suggests that the concept of type 1 diabetes as an immunemediated disease emerged rapidly over the period from 1974 to 1976 and showed many of the features of a classic paradigm shift. A few key observations triggered recognition and acceptance of the new paradigm, but the necessary context was provided by scientific developments in areas mainly unrelated to diabetes. The disease paradigm established by 1976 is still widely accepted, and its essential features have been modified only in detail by the revolution in molecular biology that has occurred over the intervening period. Notwithstanding, some of the underlying assumptions remain imprecise, unchallenged, or unconfirmed. Appreciation of the historical origin and subsequent evolution of these fundamental concepts could stimulate critical analysis and help prepare the way for a new paradigm.

Diagnostic value of serological markers for celiac disease in diabetic children and adolescents

OBJECTIVE

To determine the accuracy of antigliadin and antiendomysium antibodies for the diagnosis of celiac disease in diabetic children and adolescents with and without digestive symptoms.

STUDY DESIGN

177 children and adolescents with IDDM aged 15.4 +/- 5.4 years (mean +/- SD). Antigliadin (ELISA) and antiendomysium (IFI) antibodies were measured in 177 and 35 patients, respectively.

RESULTS

Seven of 177 patients (3.9%; 95% confidence interval: 1.1-6.7) had celiac disease. The specificities of antiendomysium antibodies test (83%), IgA-antigliadin antibodies test (80%) and IgG-antigliadin antibodies test (90%) and the positive predictive values of these antibodies (55-75%) were lower than those obtained with the combined determination of these antibodies (100%). Negative antibodies and normal mucosa in one determination did not rule out the development of celiac disease later.

CONCLUSIONS

The combined determination of antigliadin and antiendomysium antibodies is the test of choice in screening for celiac disease in diabetic patients. The yearly investigation of these antibodies is a reliable method for detecting silent celiac disease in this population.

High prevalence of thyroid autoantibodies at diagnosis of insulin-dependent diabetes mellitus in Swedish children

The prevalence of thyroglobulin autoantibodies and that of thyroid peroxidase autoantibodies were studied in serum samples from 52 children with insulin-dependent diabetes mellitus, sampled at diagnosis and before the start of insulin treatment, with 386 non-diabetic schoolchildren (11 to 13 years of age) serving as control subjects. Using exactly the same sensitive solid-phase immunosorbent radioassay for both thyroid autoantibodies, with comparable sensitivity, we found the prevalences of both autoantibodies to be higher in the insulin-dependent diabetes mellitus group than in the control group, the difference being most pronounced for thyroid peroxidase autoantibodies. Thyroglobulin autoantibodies were positive in 33% of the diabetics versus 14% in the control group (p = 0.002), and thyroid peroxidase autoantibodies were positive in 38% versus 6% (p = 0.0001). The high prevalence of thyroid autoantibodies already at diagnosis stresses the importance of early screening for thyroid disease in patients with insulin-dependent diabetes mellitus.

Helicobacter pylori infection with parietal cell antibodies in children and adolescents with insulin dependent diabetes mellitus

One hundred and seventy-seven patients with insulin dependent diabetes mellitus (IDDM) diagnosed at the pediatric age were investigated for the presence of gastric parietal cell autoantibodies (PCA). The objective was to evaluate the prevalence of PCA seropositivity and to know whether Helicobacter pylori could be a reason for a higher presence of PCA in IDDM children and adolescents. Twelve of 177 patients (6.77%; confidence interval: 3.1-10.3) had detectable PCA. Gastric pathology was studied in eight of these patients and in seven patients without PCA. Diagnosis of H. pylori infection was made on antral biopsies. None of the patients had an atrophic gastritis. Six of the eight patients with PCA had gastric mucosa colonization by H. pylori and/or chronic gastritis. According to these results, we suggest that H. pylori can be the cause of the presence of PCA positive results in diabetic children and adolescents, and diabetic patients with detectable PCA should be screened for H. pylori.

Syndrome of Type II Polyglandular Autoimmunity Associated with HLA-DR4 in a Large Kindred, Including HLA-DR3/DR4 Heterozygosity in the Probands, Identical Twins with Identical Manifestations

Autoimmune destruction and resultant failure of multiple organ systems constitute an uncommon entity known as type II polyglandular failure. Occasionally, the syndrome is familial, and in the kindreds studied, individual patients have manifested different sets of the associated diseases. We describe a large family in which the presence of HLA-DR4 was associated with development of this syndrome. More commonly, HLA-DR3 has been associated with type II polyglandular failure. The probands are monozygotic twin sisters in whom an identical set of autoimmune diseases occurred in the same order of onset and at approximately the same age. These data suggest that not only do specific factors predispose to this syndrome but also distinct factors determine which individual diseases are expressed.

Thyroid volume in type 1 diabetes patients without overt thyroid disease

An association between insulin-dependent diabetes mellitus (type 1) and thyroid diseases has long been reported, but the morphological evaluation of the thyroid in type 1 diabetes patients without overt thyroid disease has always been limited to physical examination. Ultrasonography of the thyroid gland was performed in 45 patients with type 1 diabetes without overt thyroid disease, to study thyroid volume and the prevalence of thyroid nodules. Data were compared with those obtained in 45 age- and sex-matched control subjects residing in the same area. In the patients, thyroid volume had increased on average by 46%; 35% of male and 32% of female patients had a thyroid volume exceeding the 95% confidence limits of the matched controls. The prevalence of thyroid nodules was only slightly raised. On average, free thyroxine was increased in the presence of normal triiodothyronine levels. Four patients were frankly hyperthyroid. The patients also showed a higher prevalence of thyroid-microsomal antibodies, but the thyroid hormone status was not different in relation to thyroid volume, nor was thyroid volume in relation to the presence of autoantibodies. Patients with type 1 diabetes without overt thyroid disorders may have morphological, ultrasonographically detectable alterations of the thyroid gland, the expression of a possible involvement of the thyroid in an autoimmune disorder not limited to the islet cells.

Immunogenetic heterogeneity in type 1 (insulin-dependent) diabetes among Japanese--class II antigen and autoimmune thyroid disease

HLA-DQA1 and DPB1 alleles were examined in relation to autoimmune thyroid disease (AITD) in the Japanese type 1 diabetic patients. The subjects consisted of 14 type 1 diabetic patients with Graves' disease, 12 patients with Hashimoto's thyroiditis and 32 type 1 diabetic patients without AITD. Comparisons were made with 35 normal controls. Among the type 1 diabetic patients with Graves' disease, the age at onset of diabetes was 31.8 +/- 14.6 years old, which was later than that of those without AITD (P < 0.01). DR9 was increased (57.1% vs. 25.9%, P < 0.05, RR: 3.85, chi 2:4.36) in the patients with Graves' disease. DQA1*0301 was increased and DQA1*0103 was decreased in the patients with Graves' disease and those without AITD. HLA-DPB1*0501 was increased (92.9% vs. 54.3%, P < 0.05, RR: 11.0, chi 2:6.57) in the patients with Graves' disease. These findings suggest the existence of a Graves' complicated subgroup characterized by the increasing association of DPB1*0501 and late onset of diabetes in Japanese type 1 diabetic patients. There exists a heterogeneity in Japanese type 1 diabetes.

The coexistence of systemic lupus erythematosus with other autoimmune diseases: the kaleidoscope of autoimmunity

Patients with systemic lupus erythematosis (SLE) often manifest features of other autoimmune diseases. In this review, we provide a detailed compendium of features of SLE that overlap with other conditions. This compendium is important because a critical feature in our understanding of autoimmunity has been the clustering of coexisting/different autoimmune diseases both within an affected patient and within a pedigree. Indeed, autoimmune disorders share a variety of similar clinical and serological defects. For example, all autoimmune disorders are associated with the elaboration of autoantibodies and/or the production of self-reactive mononuclear cell populations; many have high levels of immune complexes and defects in cell-mediated immunity. Several diseases share similar genetic backgrounds, as reflected by study of loci within the major histocompatibility complex. In part the coassociation is due to common genetic tendencies with different environmental precipitating agents (trigger mechanisms). It is likely that many factors can modulate the immune system to autoimmunity in the presence of an appropriate genetic background, eg, drugs, viral infections, UV irradiation, and toxins, ie, toxic oil syndrome and L-tryptophan-induced eosinophilic myalgia. The coexistence of SLE with other autoimmune diseases is an excellent venue to understand these events, and we believe that the presence of other autoimmune diseases in patients with SLE can be called the kaleidoscope of autoimmunity.

ICA and organ-specific autoantibodies among Japanese patients with early-onset insulin-dependent diabetes mellitus--the JDS study

The Japan Diabetes Society (JDS) conducted a multicenter study on the immunogenetics of insulin-dependent diabetes mellitus (IDDM) among Japanese. The previous report of the JDS study described HLA types and other immunogenetic markers in Japanese patients with IDDM. In the present report, the autoimmunity of Japanese patients was studied by measuring ICA and other organ-specific autoantibodies in patients with different durations of IDDM. The prevalences of ICA were the highest in the first year after diagnosis (73.1%) and decreased to 58.0%, 18.3% and 2.8% in 1-5 years, 5-10 years and 10 years or more after diagnosis, respectively (P < 0.01), while the prevalences of the other organ specific autoantibodies increased gradually with duration of IDDM from 20% in the first year to 35% in 10 years or more after diagnosis (P < 0.05). There were no sex differences in the prevalences of ICA but those of other organ-specific autoantibodies were significantly higher in female patients than in male patients (P < 0.01). The prevalence of ICA was not correlated with sex, age at onset or HLA types. In one of the subjects, a girl, the titers of ICA increased in parallel with a decrease in insulin secretion before the development of overt IDDM and declined thereafter. These findings suggest that IDDM might develop when the autoimmunity specific to pancreatic islets is triggered in people with underlying autoimmunity as shown by the presence of organ-specific autoantibodies other than ICA.

A case of intractable diarrhea firmly suspected to have autoimmune enteropathy

Protracted diarrhea with insulin dependent diabetes mellitus (DM) and hypothyroidism in a 9 month old Japanese girl who was firmly suspected to have autoimmune enteropathy (AIE) is reported. Her severe secretory diarrhea failed to respond to intensive antidiarrheic treatment and was gradually improved with steroid therapy. The circulating autoantibodies to enterocytes in her serum were detected by indirect immunofluorescence technique and the impaired suppressor T (Ts) cell function was proved by plaque forming assay using bead-separated CD4 or CD8 T cells together with CD19 B cells. The anti-enterocyte antibodies were exclusively of immunoglobulin M (IgM) class and were detected with the progress of the protracted diarrhea. Maximum antibody titer was obtained at the onset of DM and the disappearance of autoantibodies was associated with the resolution of the clinical symptoms and signs. The helper functions of adult CD4 T cells to induce Ig-secreting cells from adult and the patient were strikingly suppressed by adult CD8 T cells. However, the CD8 T cells from the patient lost the ability to inhibit the induction of these Ig-secreting cells when stimulated with adult CD4 T cells. Moreover, the patient's CD8 T cells stimulated rather than suppressed the induction of Ig-secreting cells from the patient when stimulated with the patient's CD4 T cells. These results suggest that the impaired Ts cell function in this patient might play some immunological role in the pathogenesis of AIE.

Autoantibodies against a novel 51 kDa islet antigen and glutamate decarboxylase isoforms in autoimmune polyendocrine syndrome type I

Beta-cell function and islet cell antibodies were studied in six patients with autoimmune polyendocrine syndrome type I. All suffered from mucocutaneous candidiasis, five had adrenocortical insufficiency and three hypoparathyroidism. All sera contained high titres of antibodies staining islets of Langerhans. Reactivity against glutamate decarboxylase, predominantly the 65 kDa isoform, was detected by immunoprecipitations and Western blots in five of the six sera, and all six sera immunoprecipitated a 51 kDa antigen from [35S]-methionine labelled rat islet cell lysates. No reactivity against this latter antigen was found in sera of patients with Type 1 (insulin-dependent) diabetes mellitus (n = 9), Graves' disease (n = 5), autoimmune gastritis (n = 4), idiopathic Addison's disease (n = 7), or stiff-man syndrome (n = 2). The 51 kDa antigen was also detected by Western blots using homogenates of rat islets and autoimmune polyendocrine syndrome type I patient sera, whereas no such reactivity was found with homogenates of testes, adrenals, small intestine, spleen, exocrine pancreas or brain. Moreover, the 51 kDa antigen was present in the rat insulinoma cell line RINm 5F but not in the SV-40 transformed, monkey kidney cell line COS, when examined by immunoprecipitations of [35S]-methionine labelled cell lysates and by Western blots. None of the patients with autoimmune polyendocrine syndrome type I had symptoms of diabetes and their insulin responses to glucose challenge were normal. The data illustrate that patients with autoimmune polyendocrine syndrome type I present an autoimmune response against islets of Langerhans, which is apparently different from that associated with classic Type 1 diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Thyroglobulin antibodies in type 1 diabetic patients and their relatives--measurement with highly sensitive assay

Autoimmunity in Type 1 (insulin-dependent) diabetes mellitus was assessed by measuring thyroglobulin antibodies (TGA) using a highly sensitive enzyme immunoassay in 65 young patients with Type 1 diabetes mellitus, 83 healthy first-degree relatives of the patients, 37 healthy control subjects and 67 healthy parents of the control subjects. TGA were found in 78.5% (51/65) of patients and were significantly more frequent in patients than in control subjects (40.5%, 15/37; P < 0.01). The prevalence of TGA in patients showed no correlation with age at onset, duration of diabetes or sex. Among the first-degree relatives the prevalence of TGA was significantly increased in mothers of patients than in mothers of the control subjects (80.0% vs. 54.3%, P < 0.05), while not significantly between fathers of patients and fathers of control subjects or between siblings of patients and control subjects. Comparing the TGA levels of TGA-positive subjects, the TGA levels in patients, their parents and their siblings were significantly higher than those in the corresponding control subjects (P < 0.05, P < 0.05 and P < 0.01, respectively). In the present study we thus more clearly demonstrated autoimmune diathesis in patients with Type 1 diabetes and in their first-degree relatives.

Studies of autoantibodies reactive with thyroid membrane antigens and insulin in non obese diabetic mice

Enzyme-linked immunosorbent assay (ELISA) was used to study the temporal relationship between the appearance of murine autoantibodies reactive to insulin and thyroid membrane antigens (TMA) and the development of diabetes and thyroiditis in the non obese diabetic (NOD) mouse. Overall, 28% of NOD mice had antibodies specific for mouse thyroid membrane antigens (MTMA), 30% had antibodies to human thyroid membrane antigens (HTMA) and 23% of NOD mice had insulin autoantibodies (IAA), in at least one of their serial monthly blood samples. Non autoimmune BALB/c mice did not develop antibodies to these antigens. Presence of IAA was associated with the development of diabetes and in 87% of cases such antibodies were detected before the diabetes was diagnosed. IAA were usually demonstrated before insulitis. No association between thyroiditis and IAA was noted. Anti-MTMA and anti-HTMA antibodies were detected more frequently in NOD mice with thyroiditis than in those without thyroid inflammation. No significant association was noted between detection of serum anti-TMA antibodies and the development of diabetes. In young mice, anti-TMA antibodies were not detected in the absence of thyroiditis. Western blot analysis of NOD sera positive for MTMA by ELISA revealed a heterogeneous pattern of reactivity. The significance of these findings with respect to the pathogenesis of diabetes and thyroiditis and their association, is discussed.

Disease concurrence in diabetes mellitus: a study of concurrent morbidity over 12 months using diabetes mellitus as an example

STUDY OBJECTIVE

The aim was to examine disease concurrence, using diabetes mellitus as an ullustrative example.

DESIGN

The study involved a general practice morbidity survey, conducted over 12 months in 1981-82. All patients who consulted their general practitioners with a diagnosis of diabetes mellitus (type 1 or type 2) were identified and the number of these who consulted with additional morbidities were counted for each rubric of the Royal College of General Practitioners' modification of the International Classification of Disease. These observed numbers were then compared with expected numbers calculated from the total non-diabetic population after standardisation by age. Standardised person consulting ratios (SPCR) were derived and the 99% confidence intervals (CI) surrounding these values calculated.

SETTING

This was a national survey involving the whole of England and Wales.

PATIENTS

The study involved 280,000 patients from selected general practices, of whom 953 males and 1035 females consulted their general practitioners with diabetes.

MEASUREMENTS AND MAIN RESULTS

In an examination of 80 disease rubrics in the diabetic population in which there were at least 20 observed or expected cases, there were 34 among males and 28 among females in which there were increased values of the SPCR, and none in which the SPCR was decreased. SPCRs were high for infections generally (bacterial, fungal, and viral) and particularly so for cardiovascular disorders and for hypothyroidism in males. Though SPCRs for upper respiratory infections were increased, those for asthma and hay fever were not. SPCRs for neoplasms as a group were not raised.

CONCLUSION

By confirming other work and widely held clinical opinion, this study has shown the potential of this data base for the examination of disease concurrence.

Thymus and autoimmunity: capacity of the normal thymus to produce pathogenic self-reactive T cells and conditions required for their induction of autoimmune disease

BALB/c athymic nu/nu mice spontaneously developed organ-specific (gastritis, thyroiditis, oophoritis, or orchitis) and systemic (arteritis, glomerulonephritis, and polyarthritis) autoimmune diseases when transplanted with neonatal BALB/c thymuses. Transplantation of thymuses from adult BALB/c mice was far less effective in inducing histologically evident organ-specific autoimmune disease in nu/nu mice. Autoimmune disease developed, however, when adult thymuses were irradiated at a T cell-depleting dose before transplantation. Engrafting newborn thymuses into BALB/c mice T cell depleted by thymectomy, irradiation, and bone marrow transplantation produced similar organ-specific autoimmune disease as well, but thymus engrafting into T cell-nondepleted BALB/c mice (i.e., mice thymectomized as adults, but not irradiated) did not, despite the fact that transplanted thymuses grew well in both groups of mice. The mice with organ-specific autoimmune disease produced autoantibodies specific for the respective organ components, such as gastric parietal cells, thyroglobulins, oocytes, or sperm. The thymus-transplanted nu/nu mice also had hypergammaglobulinemia and developed anti-DNA autoantibodies, rheumatoid factors, and immune complexes in the circulation. These results indicate that: (a) the thymus of a murine strain that does not develop spontaneous autoimmune disease can produce pathogenic self-reactive T cells that mediate organ-specific and/or systemic autoimmune diseases; and (b) such self-reactive T cells, especially those mediating organ-specific autoimmune disease, spontaneously expand and cause autoimmune disease when released to the T cell-deficient or -eliminated periphery.

Insulin autoantibodies in Graves' disease--before and after carbimazole therapy

Insulin autoantibodies (IAA) are well documented in patients with insulin-dependent diabetes (IDDM) prior to the administration of insulin and in patients with reactive hypoglycaemia--the insulin autoimmune syndrome (IAS). It has been suggested that IAA can be induced by the administration of drugs containing sulphydryl groups, such as carbimazole, and they have been frequently described in Graves' disease. An alternative explanation is the clustering of autoantibodies in autoimmune disease. We studied 39 patients (37 females, two males, age range 14 to 61 years; mean 33.8 years) with proven Graves' disease and no previous treatment with carbimazole. Fifteen of the 39 patients had a family history of other autoimmune diseases. IAA and thyroid autoantibodies were assayed at diagnosis and monthly thereafter while on treatment with carbimazole, for up to 6 months. IAA were measured using a direct-binding solid-phase ELISA and specificity was confirmed by absorption studies using insulin covalently coupled to Sepharose beads. At diagnosis 33 of the 39 patients (85%) were positive for thyroid microsomal antibodies, 13 (33%) were positive for thyroglobulin antibodies, and 4 (10%) were positive for IAA. All IAA-positive patients had microsomal antibodies at diagnosis, and two had thyroglobulin antibodies in addition. After 4 months on carbimazole, the frequency of thyroid microsomal autoantibodies was unchanged (83%), while that of anti-thyroglobulin antibodies had fallen (8.6%). All four IAA-positive patients remained positive, and studies of binding to human, porcine and bovine insulin demonstrated that one serum, initially human insulin specific, later became cross-reactive with all three. We conclude that low titres of IAA are found in Graves' disease, and are associated with the presence of autoimmunity rather than the carbimazole. Symptomatic hypoglycaemia, however, is rare in Caucasian patients.

Antithyroid and other organ-specific antibodies in Saudi Arab diabetic and normal children

Sera from 162 Saudi Arab children were examined for autoantibodies to thyroid microsomes, thyroglobulin pancreatic islet cells, gastric parietal cells, and adrenocortical cells. The subjects included a control group (n = 76) and 86 children below 14 years with Type 1 diabetes. Antithyroid antibodies were detected in 8.1% of the diabetic group and in none of the control group. Parietal cell antibodies were found in 9.3% of the diabetic group and 4.4% of the control group; 14.6% of diabetic children and 2.2% of control children were positive for islet antibodies. However, 56.3% (9/16) of those who were tested at onset of diabetes had positive islet antibodies. In none of the children could we detect adrenocortical cell antibodies.

Are thyrogastric autoantibodies associated with an increased susceptibility to developing type 1 (insulin-dependent) diabetes? A study in identical twins

To examine whether the presence of thyrogastric autoantibodies is associated with an increased susceptibility towards developing type 1 diabetes we have tested for thyroid (microsomal and thyroglobulin) and gastric-parietal cell antibodies in 86 pairs of identical twins, 47 discordant and 39 concordant for type 1 diabetes. Autoantibodies were detected in both twins of a pair in 35 and in neither twin in 45 pairs. In only 6 pairs (3 discordant) was there a discrepancy in the antibody results between co-twins. The frequency of antibodies was similar in twin pairs discordant, (21/44, 48%), and concordant, (14/36, 39%), for diabetes. Thyrogastric antibodies were not more frequent in pairs that were female, diagnosed above the age of 20, or had HLA DR3 as opposed to DR4. We conclude that thyrogastric autoantibodies are common in both type 1 diabetic patients and their non-diabetic identical twins. Their presence appears to be genetically determined but does not increase the susceptibility of developing diabetes. The presence of autoantibodies does not appear to indicate a separate aetiological type of diabetes.

Immunological aspects of diabetes mellitus: prospects for pharmacological modification

It is now well known that insulin-dependent diabetes is a chronic progressive autoimmune disease. The prolonged prediabetic phase of progressive beta-cell dysfunction is associated with immunological abnormalities. A prediabetic period is suggested by the appearance of islet cell antibodies, anti-insulin antibodies, and anti-insulin receptor antibodies. The existence of activated T lymphocytes and abnormal T cell subsets are also other markers. There is still no concensus about the use of the immunosuppression superimposed upon conventional insulin therapy in early diagnosed IDDM and the follow-up of the relatives of IDDM patients who share the genetic predisposition and serological markers for the risk of future onset of IDDM. Treatment in the prodromal period cannot be justified because a link between the disease and early markers such as ICA has not been established with certainty (Diabetes Research Program NIH, 1983). Many immunopharmacological manipulations were reported to be effective in animal models. However, most of them are not readily applied to human subjects. Moreover, IDDM patients are now believed to be heterogeneous, with a complex genetic background. HLA-DR, and more recently DQ, are closely related to the genetic predisposition to IDDM but those genes are not themselves diabetogenic. The contribution of autoimmunity does not appear to be uniform, and in some cases, the contribution of virus is considered more important. There is a lack of a marker for the future onset of IDDM. ICA and ICSA were found after mumps infection, but the existence of those autoantibodies and even the co-existence of HLA-DR3 do not always indicate the future trend to insulin dependency. More precise markers will be disclosed through the biochemical analysis of the target antigens on pancreatic beta-cell for islet antibodies and effector T cells. Much safer and more effective immunopharmacological treatment will be developed through animal experimentation using rat and mouse models. The recent development and interest in this field will further facilitate the attainment of the goal for the complete prevention of IDDM.

Evaluation of gastrin secretion in diabetic subjects with normal or abnormal cardiovascular autonomic function tests

The serum gastrin response to a meat extract drink was measured in 16 non-diabetic subjects, in 40 diabetic subjects and 9 patients with positive tests for gastric parietal cell antibodies. Standard cardiovascular autonomic function tests were also performed in diabetic subjects. The test drink produced a highly significant rise in the serum gastrin concentration (p less than 0.001). Diabetic subjects with normal cardiovascular autonomic function tests had slightly lower stimulated gastrin concentrations than non-diabetic subjects. In diabetic subjects with abnormal cardiovascular autonomic function tests the distribution of gastrin concentrations after the test drink was bimodal. Eleven out of 20 had 45-min gastrin concentrations greater than 120 pg/ml, compared with 2 out of 20 diabetics with normal cardiovascular autonomic function tests and 1 out of 16 non-diabetic subjects (p less than 0.001). Much higher gastrin responses were found in 5 out of 9 patients with positive tests for gastric parietal cell antibodies. An increased gastrin response may be found in patients with abnormal autonomic function but its value as a marker is limited by the small amplitude of the change and by the significant prevalence of atrophic gastritis, in which much higher gastrin responses may be found.

Insulin autoantibodies are associated with islet cell antibodies; their relation to insulin antibodies and B-cell function in diabetic children

Blood was drawn from 74 children, 3-16 years old, at diagnosis of Type 1 (insulin-dependent) diabetes and before the first insulin injection. Insulin autoantibodies were detected with a polyethylen-glycol-method in 27/74 (36.4%) and with an immuno-electrophoretic method in 6/74 (8.1%). Islet cell cytoplasmic antibodies detected by indirect immuno-fluorescence were found in 49/74 patients (66.2%), who included as many as 23 of the 27 patients with insulin autoantibodies determined with the polyethylen-glycol-method (p less than 0.01). The proportion of insulin autoantibody-positive patients who developed insulin antibodies during the first 9 months of insulin treatment was not significantly greater (51.8%) than that of insulin autoantibody-negative patients (44.6%), but patients with both islet cell antibodies and insulin autoantibodies at diagnosis produced more insulin antibodies during the first 9 months (p less than 0.05). There was no difference in fasting or meal stimulated serum C-peptide after 3, 9 or 18 months as related to occurrence of insulin autoantibodies and/or islet cell antibodies. The correlation between insulin autoantibodies and islet cell antibodies indicates that both types of autoantibodies reflect the same immunological process, although the lack of correlation to C-peptide may indicate that they play a minor causal role. In addition, the results show that patients with an active autoimmune process evidently tend to produce more insulin antibodies during the first months of insulin treatment, but the islet cell antibodies and insulin autoantibodies-positive patients had at least as good residual B-cell function as patients without autoantibodies at diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

De novo clinical hypothyroidism in pregnancies complicated by type I diabetes, subclinical hypothyroidism, and proteinuria: a new syndrome

Fifty-one women with type I diabetes who had normal thyroxine values before becoming pregnant were evaluated. Abnormalities of thyroid tests other than thyroxine were encountered in 26 women, of whom 8 developed a low serum thyroxine level, an elevated thyroid-stimulating hormone level, and a low insulin requirement in the second trimester subsequent to an increase in 24-hour urinary protein excretion to greater than 4 gm/24 hr. Thyroid replacement led to an increase in insulin requirement to levels appropriate for gestational age. It is concluded that the woman with type I diabetes who develops proteinuria greater than 4 gm/24 hr during gestation is at risk for the development of de novo hypothyroidism during pregnancy, evidenced by a low serum thyroxine level, an elevated thyroid-stimulating hormone level, and a drop in insulin requirement.

Type 2 diabetes in Arab patients in Kuwait

We describe the characteristics of 75 Arab Type 2 diabetic patients in Kuwait. Their age (+/- SD) at onset was 41 +/- 10 years, and fasting serum C-peptide concentration was 0.32 +/- 0.23 nmol/l (n = 51). Fifty-three percent (37/70) possessed HLA-DR3 or -DR4 epitopes, and 64% (47/73) had a family history of diabetes. Data review suggested that they could be segregated into two groups, those under 40 years old at onset (32 +/- 6 years, n = 37), and the remainder (48 +/- 6 years, n = 38) (p less than 0.001). Those in the former group had a significantly higher frequency of a family history of diabetes than those in the latter group (92% vs 38%, p less than 0.001) suggestive of a greater genetic influence on the development of Type 2 diabetes in those with early onset disease.

Immunological aspects of gastritis and pernicious anaemia

Pernicious anaemia (PA) and chronic atrophic gastritis (CAG) aggregate in families, occur more often in women, and are associated with various heritable traits such as fair skin and blue eyes. They are linked to certain HLA types. Linkages are relatively weak for A and B antigens, but somewhat stronger in the case of DR antigens. There are strong associations between PA and other organ-specific autoimmune diseases, particularly those affecting the thyroid. Discordance for PA in monozygotic twins has been reported, and it may well be that expression of the disease requires, in a genetically susceptible individual, initial injury to the gastric mucosa by some environmental agent such as a virus or some physical irritant, with perpetuation of injury then depending upon autoimmune mechanisms. Numbers of T cells are substantially increased in the gastric mucosa of patients with PA, but the ratio of T suppressor to T helper cells is normal. There is a relatively greater increase in numbers of cells not of T lineage, presumably B-cells. Gastric autoantibodies, both to different components of the parietal cell and to two sites on the IF molecule, are present in a majority of patients with PA. There is evidence that these autoantibodies, especially PCA, may be cytotoxic to parietal cells, and may also inhibit their maturation and proliferation. Antibodies to chief cells have not been described, and the parallel disappearance of these cells in atrophic gastritis is unexplained. The peripheral blood lymphocytes of some patients with autoimmune gastritis transform, or produce lymphokines, when exposed to gastric antigens, and patients with PA have been shown to have delayed type cutaneous hypersensitivity to gastric antigens. The relevance of these observations to the pathogenesis of their gastric mucosal lesion is unclear. There is a growing body of evidence to support the operation of humoral immune mechanisms in autoimmune gastritis, but this clearly does not preclude the coexistent involvement of cellular mechanisms. For example, impaired suppressor T cell function has been strongly implicated in certain other autoimmune disorders, but has received scant attention in PA. By generally accepted criteria, PA is an excellent example of an organ-specific autoimmune disease. As yet, there is no acceptable single unifying hypothesis which will account for all of the phenomena which have been described in the disease.(ABSTRACT TRUNCATED AT 400 WORDS)

Characteristics and survival of diabetic patients undergoing vitreous surgery

Characteristics, and the occurrence of other diseases, and complications related to diabetes mellitus of 91 consecutive diabetic patients who underwent vitreous surgery in 1979-1985 were examined. The mean age of the patients was 40 years (median 37, range 19-74), and the mean duration of diabetes 23 years (range 5-44). All, but one, had insulin therapy. Abnormalities in the cardiovascular and/or renal function were found in 89 of the 91 patients (98%). Signs of cardiovascular disease were observed in 58 patients (64%): 42% had elevated blood pressure (greater than or equal to 150/100 mmHg), 46% were on antihypertensive therapy, 14% had a history or signs of ischaemic heart disease, 12% had been digitalized, 7% had a history of cerebral ischaemia, and 8% had had surgery for gangrene of the lower limb. Signs of nephropathy were recorded in 64 patients (70%); 6 of them were on dialysis therapy, and two had received a kidney transplant. Symptoms possibly related to autonomic neuropathy e.g. postural hypotension, urinary tract symptoms, and gastric discomfort were found in 27%. Nine patients (10%) had some kind of thyroid disease, and two of them signs of multiple autoimmune endocrinopathy. The percentage surviving decreased from 96% at one year to 80% after 5 years of follow-up.

Effect of antithyroid autoantibodies on pancreatic islet-cell function

Insulin-dependent diabetes mellitus is frequently associated with organ-specific autoimmune diseases and/or high titers of organ-specific autoantibodies. The effects of thyroid autoantibodies on islet-cell function were examined in the present study. Islet cell surface antibody (ICSAb) was detected in sera from 6 of 40 patients with autoimmune thyroid disease (AITD) who were positive for thyroid microsomal autoantibodies (TMA). Furthermore, all of the ICSAb-positive patients had high TMA titers. In vitro study using isolated rat pancreatic islets revealed that TMA positive sera significantly suppressed glucose-induced insulin release. Only one of 19 (5%) AITD patients showed complement-dependent antibody-mediated cytotoxicity and only one of 6 AITD patients (17%) was positive for antibody-dependent cellular cytotoxicity. These results suggest that TMA has an effect on an antigen of the islet cell membrane in which insulin releasing mechanism might be involved.

Thyroid autoantibodies in HLA-genotyped type 1 diabetic families: sex-limited DR5 association with thyroid microsomal antibody

Thyroid autoantibodies are common in Type 1 diabetics and their first degree relatives and may be part of the autoimmune diathesis present within such families. We have measured the prevalence of microsomal (M-Ab) and thyroglobulin (Tg-Ab) autoantibodies in 84 HLA-typed families having a Type 1 diabetic child, using enzyme-linked immunosorbent assay techniques. Thyroid autoantibodies were detectable in 201/407 (49%) individuals in these families. Both autoantibodies were significantly more frequent in the subsets of parents, diabetic children and their non-diabetic siblings than in groups of control adults and children. The prevalence of these autoantibodies in the diabetic families was increased in both sexes with a female:male ratio of 1.4:1. Antigen DR5 was significantly associated with M-Ab production but only for male subjects (P = 0.005 after correction for the number of DR antigens tested). No significant associations were encountered for Tg-Ab. Within-family analyses indicated that thyroid autoantibodies occurred with increased prevalence in HLA-identical or haplo-identical siblings of autoantibody-positive index cases in comparison to control children. We conclude the DR association with thyroid autoantibody production in this diabetes-selected population was thyroiditis-related and not diabetes-related, and the DR5 association was restricted to males and the production of M-Ab. These data are consistent with the hypothesis that multiple genetic and non-genetic factors played a role in the high prevalence of thyroid autoantibodies in this population.

Cytochemistry of circulating lymphocytes in diabetes mellitus with and without retinopathy and in newly diagnosed type I (insulin dependent) diabetes

Cytochemical studies have been performed on peripheral blood lymphocytes of 68 diabetic subjects, with various conditions of metabolic control, and 15 newly diagnosed insulin-dependent diabetic patients. 20 patients of the 1 group had diabetic retinopathy. In diabetic patients periodic acid Schiff positivity, acid phosphatase, and N-acetyl-beta-glucosaminidase activities of lymphocytes are fairly impaired, particularly in insulin-dependent diabetes. Concerning the alpha-naphthyl-acetate-esterase activity, the percentage of positive cells with coarse granules is significantly reduced (p less than 0.001) in diabetic patients as compared to controls, without difference related to age and sex. These abnormalities are more evident in patients with poor glyco-metabolic control. In patients with newly diagnosed insulin-dependent diabetes we have found a further decrease in alpha-naphthyl-acetate-esterase activity, and an increase in acid phosphatase and N-acetyl-beta-glucosaminidase activities. Cyto-enzymatic activities are not significantly different in subjects with diabetic retinopathy. The results of peripheral lymphocyte enzymatic activities in diabetics could be related to a depression of the cell-mediated immunity and could enhance the infections risk of these patients. Furthermore our data show an altered immunological balance in subjects with newly diagnosed type I diabetes.

Polyglandular autoimmune syndromes

Dysfunction of multiple endocrine glands may develop as the result of hypopituitarism, various infiltrative disorders, or an organ-specific autoimmune mechanism. When dysfunction of two or more endocrine glands occurs in association with circulating organ-specific antibodies directed against the involved glands, the term polyglandular autoimmune syndrome is applied. Characteristics of polyglandular autoimmunity include specific patterns of disease association and frequently a family history of similar involvement. The principal endocrine components of these syndromes are adrenal insufficiency, autoimmune thyroid disease, insulin-dependent diabetes mellitus, and premature gonadal failure. In addition, primary hypoparathyroidism is a key feature of one form of polyglandular autoimmunity that occurs in children. Several nonendocrine organ-specific autoimmune disorders are also associated with polyglandular autoimmunity, of which pernicious anemia is the most frequent. The underlying abnormality responsible for polyglandular autoimmunity is most likely a defect in T suppressor cell function, but there is evidence that aberrant expression of HLA DR antigens also plays an important role in the pathogenesis of these disorders.

Value of insulin autoantibodies as serum markers for insulin-dependent diabetes mellitus

Insulin autoantibodies (IAA) were studied in newly diagnosed insulin-dependent diabetics before the start of insulin treatment and in unaffected identical twins of insulin-dependent diabetics. In 15 of the 40 (38%) diabetics and 27 of the 58 (47%) twins IAA levels exceeded those of 100 controls. Frequency of IAA in unaffected twins was not related to duration of diabetes in their affected twin. In 11 unaffected twins, IAA levels differed in two samples taken 1-12 years apart; IAA were detected at least once in all twins and in one on both occasions. IAA in the twins were not related to the presence of islet-cell antibodies or to HLA-DR 3 or 4. As the unaffected twins of longstanding diabetics are unlikely to develop diabetes, these observations suggest that IAA do not always presage diabetes and are probably not a consequence of the disease; they may reflect an inherited autoimmune tendency to diabetes.