Type 1 diabetes and associated autoimmune diseases

Prevalence of autoimmune diseases in an admixed population of patients with type 1 diabetes: a multicenter study in Brazil

BACKGROUND/OBJECTIVES

The primary aim of this study was to evaluate the prevalence of autoimmune diseases (AIDs) and its associated factors in an admixed Brazilian population of patients with type 1 diabetes (T1D). The secondary one was to determine the relationship between AIDs and the occurrence of diabetes-related chronic complications (DRCC).

METHODS

This cross-sectional, nationwide survey was conducted in 13 public clinics in 11 Brazilian cities. Overall, 1,760 patients were included; 967 females (55.9%), 932 (54%) Caucasians, aged 29.9 ± 11.9 years, age at diagnosis 14.8 ± 8.9 years, diabetes duration 15.5 ± 9.3 years and 12.2 ± 3.8 years of school attendance. AIDs were retrieved from medical records or self-report and stratified as follows: absence of AIDs, only autoimmune thyroid disease (AITD), and other AIDs including the combination with AITD (hyper or hypothyroidism).

RESULTS

The prevalence of AIDs was 19.5% being AITDs (16.1%), the most frequently found. A higher prevalence of hypertension, dyslipidemia and overweight or obesity was found in patients who had exclusively AITDs. A higher prevalence of diabetic retinopathy (DR) was observed in patients with AITDs and patients with other AIDs in combination with AITDs. Chronic kidney disease (CKD) was more prevalent in patients with only AITDs. Lower levels of HbA1C, were observed in patients with isolated AITDs or with other AIDs, regardless of the presence of AITD. Hierarchical multivariate analysis, showed that AIDs were associated with female gender, older age, and longer diabetes duration, self-reported color-race (White and Brown), geographic region (Brazilian North/Northeast region) and higher anti-TPO levels (≥ 35 UI/ml).

CONCLUSIONS

In conclusion, Brazilian patients with T1D, belonging to a highly ethnically admixed population, had an important prevalence of AIDs, mostly AITDs, that was associated with female gender, self-reported color-race, older age and longer diabetes duration. Moreover, these patients also had a higher prevalence of DRCC. Even though we highlight the importance of investigating the presence of AIDs at diagnosis and at regular intervals, it is unclear whether screening and early detection of additional AIDs may improve the clinical outcomes in individuals with T1D. Future prospective studies are necessary to establish the interplay between T1D, AIDs and DRCC.

Association between Type 1 Diabetes Mellitus and Parkinson's Disease: A Mendelian Randomization Study

While much evidence suggests that type 2 diabetes mellitus increases the risk of Parkinson's disease (PD), the relationship between type 1 diabetes mellitus (T1DM) and PD is unclear. To study their association, we performed a two-sample Mendelian randomization (MR) using the following statistical methods: inverse variance weighting (IVW), MR-Egger, weight median, and weighted mode. Independent datasets with no sample overlap were retrieved from the IEU GWAS platform. All the MR methods found a lower risk of PD in T1DM (IVW-OR 0.93, 95% CI 0.91-0.96, p = 3.12 × 10-5; MR-Egger-OR 0.93, 95% CI 0.88-0.98, p = 1.45 × 10-2; weighted median-OR 0.93, 95% CI 0.89-0.98, p = 2.76 × 10-3; and weighted mode-OR 0.94, 95% CI 0.9-0.98, p = 1.58 × 10-2). The findings were then replicated with another independent GWAS dataset on T1DM (IVW-OR 0.97, 95% CI 0.95-0.99, p = 3.10 × 10-3; MR-Egger-OR 0.96, 95% CI 0.93-0.99, p = 1.08 × 10-2; weighted median-OR 0.97, 95% CI 0.94-0.99, p = 1.88 × 10-2; weighted mode-OR 0.97, 95% CI 0.94-0.99, p = 1.43 × 10-2). Thus, our study provides evidence that T1DM may have a protective effect on PD risk, though further studies are needed to clarify the underlying mechanisms.

The association between type 1 diabetes and exercise/physical activity and prolongation of the honeymoon phase in patients

In type 1 diabetes (T1D), pancreatic beta cells are destroyed by the immune system, causing chronic hyperglycemia and micro and macrovascular complications. However, some people experience a 'honeymoon' phase (or partial remission) after being diagnosed with type 1 diabetes. During this phase, a substantial amount of insulin is still produced by the pancreas, helping to reduce blood sugar levels and the requirement for external insulin. The clinical significance of this phase lies in the potential for pharmacological and non-pharmacological interventions during this time frame to either slow down or arrest beta-cell destruction. Clearly, we need to continue researching novel therapies like immunomodulatory agents, but we also need to look at potentially effective therapies with acceptable side effects that can serve as a complement to the medicines currently being studied. Physical activity and exercise, regardless of its type, is one of the factors its impact on the control of diabetes is being investigated and promising results have been achieved. Although there are still limited reports in this regard, there is some evidence to suggest that regular physical exercise could prolong the honeymoon period in both adults and children. In this review, having described the immune base of type 1 diabetes, we outline the benefits of exercise on the general health of individuals with T1D. Moreover, we centered on the honeymoon and current evidence suggesting the effects of physical activity and exercise on this phase duration.

Autoimmune Polyendocrinopathy in a Pediatric Patient Presenting With Multisystem Inflammatory Syndrome in Children (MIS-C)

Multisystem inflammatory syndrome (MIS) is a well-known potential sequela of COVID-19 infection. Though prevalence is higher in certain populations, this syndrome is a rare occurrence in children. Beyond MIS, there has been increasing research into COVID infection and the subsequent onset of autoimmune conditions, such as diabetes. However, evidence of a poly-endocrinopathy developing after COVID infection is lacking, and evidence within the pediatric population is virtually nonexistent. In this case, we present the evolution of an autoimmune polyglandular syndrome (APS) type 2 phenotype, consisting of type 1 diabetes, Graves' disease, and adrenal insufficiency, after diagnosis of multisystem inflammatory syndrome of children (MIS-C) in a pediatric patient.  A 15-year-old biracial female without significant past medical history tested positive for COVID-19 and two weeks later presented with respiratory symptoms and other systemic signs. She was admitted for further evaluation and was found to have elevated inflammatory markers, EKG (electrocardiogram) abnormalities, and lab evidence of organ damage. The patient was diagnosed with MIS-C, and treatment was initiated with eventual discharge. One year after this initial visit, the patient returned to the hospital due to weight loss, difficulty breathing, polyuria, polydipsia, nausea, vomiting, and fatigue. A steroid course for MIS-C treatment had been completed three months prior. Exam and lab results confirmed diabetic ketoacidosis (DKA), and the patient was diagnosed with new-onset type 1 diabetes. Further testing determined that she was glutamic acid decarboxylase 65 (GAD-65) positive. DKA was managed in the hospital, and the patient was subsequently discharged with an insulin regimen and endocrine follow-up. A couple of months later, the patient returned to the emergency department (ED) due to two weeks of dyspnea on exertion and dizziness. Since her previous admission for DKA, the patient had contracted COVID-19 again and recovered from her respiratory symptoms. Physical exam and labs were grossly unremarkable; however, the patient had EKG abnormalities and an episode of severe bradycardia, prompting hospitalization. Thyroid workup revealed thyrotoxicosis due to Graves' disease. Due to intermittent hypotension, adrenal labs were obtained. She was found to have adrenal insufficiency as well, with a positive 21-hydroxylase antibody. Throughout these hospitalizations, the patient suffered from skin and hair changes as well, ultimately requiring dermatological intervention.

Recurrence risk of autoimmune thyroid and endocrine diseases

BACKGROUND AND OBJECTIVE

The recurrence risk ratio (λ) expresses the risk ratio of index patients' first-degree relatives developing a disease as compared to the general population and is a quantitative measure of the genetic contribution to the disease. This paper offers the results of a specialized center as well as a review of the pertinent literature.

METHODS

Data from 3315 consecutive subjects followed at an ORPHAN academic tertiary referral expert center for endocrine autoimmunity as well as 419 unrelated German families were collected. λ was assessed based on 806 well-documented subjects, 299 index patients with autoimmune glandular (AIGD) and non-endocrine diseases and 507 of their first-degree relatives (328 children, 179 siblings).

RESULTS

As many as 36% of relatives of patients with autoimmune diseases (AID) were affected by various autoimmune conditions. Twenty-five percent and 23% of all relatives had an AIGD or an autoimmune thyroid disease (AITD), respectively. Furthermore, 29% and 25% of relatives of index cases with polyglandular (PGA) and monoglandular (MGA) autoimmunity were affected. The recurrence risk for AITD was increased 16-fold in both children and siblings compared to the general population (λ, 95% CI 16, 11-21 and 16, 12-19, respectively). Furthermore, λ for AITD/AIGD was 21.62 (95% CI 14.17-30.69)/17.57 (11.80-24.36) and 13.48 (8.42-20.52)/10.68 (6.76-16.02) for siblings of patients with PGA and MGA, respectively. Overall, a strong genetic component for AITD and AIGD with a significant genetic impact on the development of PGA was demonstrated.

CONCLUSION

These novel results strongly recommend the screening for AITD and AIGD in children and siblings of index patients with AITD.

Type 1 Diabetes (T1D) and Latent Autoimmune Diabetes in Adults (LADA): The Difference Between a Honeymoon and a Holiday

Type 1 diabetes mellitus (T1D) is a chronic autoimmune disease in which destruction of the insulin-producing β-cells in the pancreatic islets requires regular lifelong insulin replacement therapy, the only lifesaving treatment available at this time. In young persons with a genetic predisposition, it usually manifests after being exposed to environmental triggers. A subtype of autoimmune diabetes mellitus (ADM) that typically occurs in adulthood is often referred to as latent autoimmune diabetes of adults (LADA). LADA is characterized by a milder process of β-cells destruction and less intensive insulin treatment, which may become necessary even many years after diagnosis. Genetic predisposition of T1D carries an increased risk for other autoimmune diseases, such as autoimmune thyroiditis, the most frequently associated condition, and pernicious anaemia (PA), present in approximately 4% of all individuals with T1D. Here, we describe the case of a 90-year-old woman with vitiligo and a mute medical history who was admitted to our University Hospital in Perugia with hyperglycaemia and severe anaemia due to vitamin B12 (VB12) depletion. A short time after setting the beginning treatment with a basal-bolus insulin regimen, her insulin requirement rapidly declined and treatment with sitagliptin, a dipeptidyl peptidase-4 inhibitor (DPP4), was started. A complete autoimmunity screening panel showed that GAD65 and intrinsic factor autoantibodies were positive.

T cell transgressions: Tales of T cell form and function in diverse disease states

Insights into T cell form, function, and dysfunction are rapidly evolving. T cells have remarkably varied effector functions including protecting the host from infection, activating cells of the innate immune system, releasing cytokines and chemokines, and heavily contributing to immunological memory. Under healthy conditions, T cells orchestrate a finely tuned attack on invading pathogens while minimizing damage to the host. The dark side of T cells is that they also exhibit autoreactivity and inflict harm to host cells, creating autoimmunity. The mechanisms of T cell autoreactivity are complex and dynamic. Emerging research is elucidating the mechanisms leading T cells to become autoreactive and how such responses cause or contribute to diverse disease states, both peripherally and within the central nervous system. This review provides foundational information on T cell development, differentiation, and functions. Key T cell subtypes, cytokines that create their effector roles, and sex differences are highlighted. Pathological T cell contributions to diverse peripheral and central disease states, arising from errors in reactivity, are highlighted, with a focus on multiple sclerosis, rheumatoid arthritis, osteoarthritis, neuropathic pain, and type 1 diabetes.

Natural Killer Cells as Key Mediators in Type I Diabetes Immunopathology

The immunopathology of type I diabetes (T1D) presents a complicated case in part because of the multifactorial origin of this disease. Typically, T1D is thought to occur as a result of autoimmunity toward islets of Langerhans, resulting in the destruction of insulin-producing cells (β cells) and thus lifelong reliance on exogenous insulin. However, that explanation obscures much of the underlying mechanism, and the actual precipitating events along with the associated actors (latent viral infection, diverse immune cell types and their roles) are not completely understood. Notably, there is a malfunctioning in the regulation of cytotoxic CD8+ T cells that target endocrine cells through antigen-mediated attack. Further examination has revealed the likelihood of an imbalance in distinct subpopulations of tolerogenic and cytotoxic natural killer (NK) cells that may be the catalyst of adaptive immune system malfunction. The contributions of components outside the immune system, including environmental factors such as chronic viral infection also need more consideration, and much of the recent literature investigating the origins of this disease have focused on these factors. In this review, the details of the immunopathology of T1D regarding NK cell disfunction is discussed, along with how those mechanisms stand within the context of general autoimmune disorders. Finally, the rarer cases of latent autoimmune, COVID-19 (viral), and immune checkpoint inhibitor (ICI) induced diabetes are discussed as their exceptional pathology offers insight into the evolution of the disease as a whole.