The Coincidence of Newly Diagnosed Type 1 Diabetes Mellitus with IgM Antibody Positivity to Enteroviruses and Respiratory Tract Viruses

The intersection of influenza infection and autoimmunity

The relationship between viral infection and autoimmune manifestations has been emerging as a significant focus of study, underscoring the intricate interplay between viral infections and the immune system. Influenza infection can result in a spectrum of clinical outcomes, ranging from mild illness to severe disease, including mortality. Annual influenza vaccination remains the most effective strategy for preventing infection and its associated complications. The complications arising from acute influenza infection are attributable not only to the direct effects of the viral infection but also to the dysregulated immune response it elicits. Notably, associations between influenza and various autoimmune diseases, such as Guillain-Barré Syndrome (GBS), Type 1 Diabetes (T1D), and antiphospholipid syndrome, have been reported. While viral infections have long been recognized as potential triggers of autoimmunity, the underlying mechanisms remain to be elucidated. Here, we described the pathophysiology caused by influenza infection and the influenza-associated autoimmune manifestations. Current advances on the understanding of the underlying immune mechanisms that lead to the potential strategies were also summarized.

Association between COVID-19 and the incidence of type 1 diabetes in Portugal - a registry study

BACKGROUND

Viral respiratory infections may precipitate type 1 diabetes (T1D). A possible association between the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for COVID-19, and the incidence of T1D is being determined. This study was carried out using Portuguese registries, aiming at examining temporal trends between COVID-19 and T1D.

METHODS

Hospital data, comparing the incidence before and during the COVID-19 pandemic, from children and young adults diagnosed with new-onset T1D, was acquired beginning in 2017 and until the end of 2022. Data was obtained from nine different Portuguese hospital units. The impact of the COVID-19 pandemic, beginning in March 2020, was assessed comparing the annual numbers of new-onset T1D cases. The annual median levels of glucose, glycated hemoglobin (HbA1c) and fasting C-peptide at T1D diagnosis were compared. The annual number of diabetic ketoacidosis (DKA) episodes among new T1D cases was also assessed at two centers.

RESULTS

In total, data from 574 newly diagnosed T1D patients was analyzed, including 530 (92.3%) children. The mean ages for child and adult patients were 9.1 (SD 4.4) and 32.8 (SD 13.6) years, respectively. 57.8% (331/573) were male, one patient had unknown sex. The overall median (25-75 percentiles) levels of glucose, HbA1c and fasting C-peptide at diagnosis were 454 mg/dL (356-568), 11.8% (10.1-13.4) and 0.50 µg/L (0.30-0.79), respectively. DKA at T1D diagnosis was present in 48.4% (76/157). For eight centers with complete 2018 to 2021 data (all calendar months), no overall significant increase in T1D cases was observed during the COVID-19 pandemic, i.e. 90 cases in 2018, 90 cases in 2019, 112 in 2020 and 100 in 2021 (P for trend = 0.36). Two of the centers, Faro (CHUA) and Dona Estefânia (CHULC) hospitals, did however see an increase in T1D from 2019 to 2020. No significant changes in glucose (P = 0.32), HbA1c (P = 0.68), fasting C-peptide (P = 0.20) or DKA frequency (P = 0.68) at the time of T1D diagnosis were observed over the entire study period.

CONCLUSION

The T1D incidence did not increase significantly, when comparing the years before and during the COVID-19 pandemic, nor did key metabolic parameters or number of DKA episodes change.

Viruses as a potential environmental trigger of type 1 diabetes mellitus (Review)

The etiopathogenesis of type 1 diabetes mellitus (T1DM) is a complex multifactorial process that involves an intricate network of genetic, epigenetic, immunological, and environmental factors. Despite the advances in recent years, some aspects of the mechanisms involved in triggering the disease are still unclear. Infections with certain viruses have been suggested as possible environmental triggers for the autoimmune process that leads to selective and progressive destruction of pancreatic β-cells and insufficiency of insulin production, which is its hallmark. In this review, advances in knowledge and evidence that suggest the participation of certain viruses in the mechanisms of disease initiation and progression are described. It has been accepted that environmental factors, including viruses, can initiate and possibly sustain, accelerate, or slow down the autoimmune process and consequently damage insulin-producing pancreatic β-cells. Although the role of these agents, especially human enteroviruses, has been exhaustively studied as the most likely triggers of the activation of autoimmunity that destroys pancreatic islets and leads to T1DM, certain doubts remain. Clinical epidemiological and experimental studies in humans and animals provide consistent and increasing evidence that persistent viral infections, especially with human enteroviruses and rotavirus infections, are associated with an increased risk of the disease in individuals genetically predisposed to autoimmunity.

Diabetogenic viruses: linking viruses to diabetes mellitus

Diabetes Mellitus (DM) is a group of chronic metabolic diseases distinguished by elevated glycemia due to the alterations in insulin metabolism. DM is one of the most relevant diseases of the modern world, with high incidence and prevalence worldwide, associated with severe systemic complications and increased morbidity and mortality rates. Although genetic factors and lifestyle habits are two of the main factors involved in DM onset, viral infections, such as enteroviruses, cytomegalovirus, hepatitis C virus, human immunodeficiency virus, severe acute respiratory syndrome coronavirus 2, among others, have been linked as triggers of type 1 (T1DM) and type 2 (T2DM) diabetes. Over the years, various groups identified different mechanisms as to how viruses can promote these metabolic syndromes. However, this field is still poorly explored and needs further research, as millions of people live with these pathologies. Thus, this review aims to ex-plore the different processes of how viruses can induce DM and their contribution to the prevalence and incidence of DM worldwide.

Seasonality and geography of diabetes mellitus in United States of America dogs

The diagnosis of type 1 diabetes mellitus (DM) in humans is associated with high altitude, few sunshine hours, cold climate, and winter. The goals of this study were to investigate seasonal and geographic patterns of DM diagnosis in United States of America (USA) dogs with juvenile and mature onset DM. Data were collected by means of an online survey widely distributed in the USA through breed clubs, academic veterinary institutions, private veterinary referral practices, social media outlets, and the American Kennel Club. Juvenile DM (JDM) and mature onset DM were defined as DM with an age of onset <365 days and DM with an age of onset ≥365 days, respectively. Meteorological seasons were defined as: winter from December through February, spring from March through May, summer from June through August, and fall from September through November. Four geographic regions were also defined as the West, North, South, and Central regions of the USA. Nonoverlapping 95% confidence intervals (CI) for season, geographic region, and breed specific proportions of dogs with JDM were considered statistically significantly different. The study included 933 dogs with mature onset DM and 27 dogs with JDM. Dogs were diagnosed with DM significantly more in the winter and northern USA compared to all other seasons and all other geographic regions, respectively. The prevalence of JDM among dogs with DM was 2.8%. The proportion of dogs with JDM among pure breeds was not significantly different than the proportion of JDM in mixed breed dogs. It is concluded that winter and cold climate could be shared environmental factors influencing DM expression in dogs and humans. Additionally, pure breed dogs do not appear to be at increased risk for JDM compared to mixed breed dogs, indicating that factors other than genetics could influence spontaneous JDM development in dogs.

Dysregulation of circulating follicular helper T cells in type 2 diabetic patients with diabetic retinopathy

Inflammation is known to be involved in the progression of diabetic retinopathy. Follicular helper T cells (Tfh) play critical roles in the differentiation of long-live plasma cells and production of antibodies, whereas circulating CD4⁺CXCR5⁺ T cells may act as a counterpart to measure Tfh cell disorders. In this study, we investigated whether Tfh could be involved in the development of diabetic retinopathy (DR) by assessing circulating Tfh cells in peripheral blood. Data showed that serum levels of total IgG and IgA were both significantly increased in type 2 diabetes mellitus (T2DM) patients with proliferative diabetic retinopathy (PDR) than with non-PDR. Also, B cell activation and differentiation were both enhanced in T2DM patients with PDR. Little changes were detected in levels of Th1, Th2, and Th17 cells. As indicated by elevated serum levels and supernatant from cultured PBMC of IL-21, we found increased circulating Tfh cells in PDR patients with dysregulated subsets. This study suggests the involvement of circulating Tfh cells in DR and, in particular, the pathogenesis of PDR.

Association Between Enterovirus Infection and Type 1 Diabetes Risk: A Meta-Analysis of 38 Case-Control Studies

OBJECTIVE

The association between enterovirus infection and type 1 diabetes (T1D) is controversial, and this meta-analysis aimed to explore the correlation.

METHODS

PubMed, Embase, Web of Science, and Cochrane Database were searched from inception to April 2020. Studies were included if they could provide sufficient information to calculate odds ratios and 95% confidence intervals. All analyses were performed using STATA 15.1.

RESULTS

Thirty-eight studies, encompassing 5921 subjects (2841 T1D patients and 3080 controls), were included. The pooled analysis showed that enterovirus infection was associated with T1D (P < 0.001). Enterovirus infection was correlated with T1D in the European (P < 0.001), African (P = 0.002), Asian (P = 0.001), Australian (P = 0.011), and Latin American (P = 0.002) populations, but no conclusion could be reached for North America. The association between enterovirus infection and T1D was detected in blood and tissue samples (both P < 0.001); no association was found in stool samples.

CONCLUSION

Our findings suggest that enterovirus infection is associated with T1D.

Autoimmune thyroid disease and type 1 diabetes mellitus: same pathogenesis; new perspective?

Autoimmune thyroid disease (AITD) and type 1 diabetes mellitus (T1DM) are two common autoimmune diseases that can occur concomitantly. In general, patients with diabetes have a high risk of AITD. It has been proposed that a complex genetic basis together with multiple nongenetic factors make a variable contribution to the pathogenesis of T1DM and AITD. In this paper, we summarize current knowledge in the field regarding potential pathogenic factors of T1DM and AITD, including human leukocyte antigen, autoimmune regulator, lymphoid protein tyrosine phosphatase, forkhead box protein P3, cytotoxic T lymphocyte-associated antigen, infection, vitamin D deficiency, and chemokine (C-X-C motif) ligand. These findings offer an insight into future immunotherapy for autoimmune diseases.

Incidence of new onset type 1 diabetes in siblings of index cases with type 1 diabetes within the first 11 years in Turkish children

AIM

Although newly diagnosed type 1 diabetes mellitus (T1DM) occurs sporadically in childhood, there is an increased risk of T1DM for first-degree relatives of patients that endure into the advanced years. Determination of T1DM incidence in siblings of children with T1DM helps predict the development of new cases. This study focuses on the incidence of the disease in siblings of children with T1DM.

METHOD

A total of 1497 siblings of 850 children (403 female; 447 male) diagnosed with T1DM between 2007 and 2018 years were retrospectively screened for T1DM. The patients were divided into four onset age groups: 0-4, 5-9, 10-14 and ≥15. The annual incidence was calculated for the region.

RESULTS

A total of 34 siblings diagnosed with T1DM were detected. The incidence relating to the years investigated was between 7.42 and 11.73/100 000 for the newly diagnosed indexes while it ranged between 0 and 5.8% for siblings. The 5-9 year group was the most commonly diagnosed onset age group in index (n = 312) and siblings (n = 20). For siblings, the male sex and 5-9 aged at diagnosis of index were significant risk factors for development of T1DM (OR:2.35 and 2.85).

CONCLUSION

This study shows that in the first years following the diagnosis of an index, incidence of T1DM among the siblings can rise up to 5.8%, and the age group of 5-9 in the index and the male sex in the sibling are the most important risk factors. These findings show that the risk for siblings of children with T1DM remarkably increases in the first years after diagnosis in index cases.

Qualitative and Quantitative Analysis of B-Cell-Produced Antibodies in Vitreous Humor of Type 2 Diabetic Patients with Diabetic Retinopathy

AIM

To analyze the levels of B-cell-produced antibodies in the vitreous humor of patients with or without diabetic retinopathy (DR) both qualitatively and quantitatively.

METHODS

A total of 52 type 2 diabetes mellitus (T2DM) with DR patients and 52 control subjects without diabetes mellitus or inflammatory diseases were included in this prospective study. The levels of immunoglobulin (Ig)A, IgM, and IgG subtypes were measured using a magnetic color-bead-based multiplex assay.

RESULTS

The concentrations of IgA, IgM, and total antibodies in the DR group were significantly higher than those in the control group (all p < 0.001), but there was no significant difference in the 4 IgG subtypes between the two groups after Bonferroni correction. Pearson's correlation analysis revealed low negative correlations between levels of antibodies (IgA, IgM) and estimated glomerular filtration rate (eGFR, r = -0.443, r = -0.377, respectively, both p < 0.05). Furthermore, multiple linear regression analysis yielded three equations to predict the concentrations of IgA, IgM, and total antibodies in the vitreous humor according to eGFR and other clinical variables (r = 0.542, r = 0.461, and r = 0.312, respectively, all p < 0.05).

CONCLUSION

Increased levels of IgA, IgM, and total antibodies produced by B cells were observed in the vitreous humor of T2DM patients with DR. There were low negative correlations between levels of antibodies (IgA, IgM) and eGFR.