Autoimmunity and insulin-dependent diabetes

Multiple influences of the COVID-19 pandemic on children with diabetes: Changes in epidemiology, metabolic control and medical care

The coronavirus disease 2019 (COVID-19) pandemic has heavily affected health worldwide, with the various forms of diabetes in children experiencing changes at various levels, including epidemiology, diabetic ketoacidosis rates and medical care. Type 1 diabetes showed an apparent increase in incidence, possibly owing to a direct damage of the virus to the β-cell. Diabetic ketoacidosis also increased in association with the general fear of referring patients to the hospital. Most children with diabetes (both type 1 and type 2) did not show a worsening in metabolic control during the first lockdown, possibly owing to a more controlled diet by their parents. Glucose sensor and hybrid closed loop pump technology proved to be effective in all patients with type 1 diabetes during the pandemic, especially because the downloading of data allowed for the practice of tele-medicine. Telemedicine has in fact grown around the world and National Health Systems have started to consider it as a routine activity in clinical practice. The present review encompasses all the aspects related to the effects of the pandemic on the different forms of diabetes in children.

Pancreatic islets seeded in a novel bioscaffold forms an organoid to rescue insulin production and reverse hyperglycemia in models of type 1 diabetes

Therapeutic approaches to combat type 1 diabetes (T1D) include donor pancreas transplantation, exogenous insulin administration and immunosuppressive therapies. However, these clinical applications are limited due to insufficient tissue compatible donors, side effects of exogenous insulin administration and/or increased onset of opportunistic infections attributable to induced global immunosuppression. An alternative approach to alleviate disease states is to utilize insulin-producing pancreatic islets seeded in a bioscaffold for implantation into diabetic recipients. The present studies now report that a newly developed cationic polymer biomaterial serves as an efficient bioscaffold for delivery of donor syngeneic pancreatic islet cells to reverse hyperglycemia in murine streptozotocin induced- or non-obese diabetic mouse models of T1D. Intraperitoneal implantation of pancreatic islets seeded within the copolymer bioscaffold supports long-term cell viability, response to extracellular signaling cues and ability to produce soluble factors into the microenvironment. Elevated insulin levels were measured in recipient diabetic mice upon implantation of the islet-seeded biomaterial coupled with reduced blood glucose levels, collectively resulting in increased survival and stabilization of metabolic indices. Importantly, the implanted islet-seeded biomaterial assembled into a solid organoid substructure that reorganized the extracellular matrix compartment and recruited endothelial progenitors for neovascularization. This allowed survival of the graft long-term in vivo and access to the blood for monitoring glucose levels. These results highlight the novelty, simplicity and effectiveness of this biomaterial for tissue regeneration and in vivo restoration of organ functions.

Cell-mediated immune responses to GAD and beta-casein in type 1 diabetes mellitus in Thailand

We measured the cell-mediated immune response to GAD and bovine beta-casein in 38 type 1 and 37 type 2 diabetic patients who visited diabetic clinics or who were hospitalized in Bangkok, Thailand, and in 43 normal controls, by using a lymphoproliferation assay. Positive results against GAD were found in 29/38 (76.3%) type 1, 6/37 (16.2%) type 2 diabetic patients and 1/43 (2.3%) normal controls. Positive results against bovine beta-casein were found in 18/38 (47.4%), 5/37 (13.5%) and 1/43 (2.3%) of these subjects, respectively. The frequencies of the positive results and the magnitude of the responses to both antigens in type 1 diabetic patients were significantly higher than those in the other two groups (P<0.001). In addition, the prevalence of a positive lymphoproliferative response to these antigens in type 1 diabetic patients was higher than that of anti-GAD antibody positivity in the same group of subjects (26.3%). Thus, the prevalence of positive lymphoproliferative response to GAD in type 1 diabetic patients studied was higher than the prevalence of other autoimmune markers previously reported in type 1 diabetic patients in Thailand.

Aspects of the etiology, prediction, and prevention of insulin-dependent diabetes mellitus in childhood

This article focuses on recent developments that have defined the autoimmune nature of this entity and its genetic basis, especially the crucial roles of aspartic acid at position 57 of the DQ beta chain and arginine at position 52 of the DQ alpha chain of the HLA complex on chromosome 6 in conferring susceptibility; other genetic markers on other genes are mentioned. These genetic markers help to explain the worldwide differences in prevalence and incidence of type 1 diabetes. Because the autoimmune process may be gradual, markers of beta pancreatic cell damage, such as islet cell antibodies, glutamic acid decarboxylase antibodies, and insulin autoantibodies, coupled with evidence of progressive failure of insulin secretion may be used to predict the future onset of disease. In turn, accurate prediction may permit preventive intervention. Two intervention trials are mentioned: (1) Diabetes Prevention Trial for Type 1, a multicenter trial in the United States using insulin; and (2) European Nicotinamide Diabetes Intervention Trial in Europe using nicotinamide as the preventive or delaying agent. These first steps reflect the remarkable progress and understanding of this major problem of childhood and the hopes for its future prevention.

Sicca syndrome in patients infected with the human immunodeficiency virus

PURPOSE

To investigate an association of the severity of the human immunodeficiency virus (HIV) disease with decreased tear production in a controlled setting.

PATIENTS AND METHODS

Seventy-two patients (144 eyes) and 30 age- and sex-matched control subjects (60 eyes) were studied prospectively. Tear production was measured using the Schirmer I test (measured in millimeters after 5 minutes). Patients were classified into three clinical groups: asymptomatic HIV infection, lymphadenopathy syndrome (LAS) or acquired immune deficiency syndrome (AIDS)-related complex (ARC), and AIDS. Additionally, patients were classified according to the CD4+ lymphocyte count.

RESULTS

Tear production (mean +/- standard deviation) did not differ (P = 0.32) among eyes of patients with asymptomatic HIV infection (17.1 +/- 10.8; n = 14), LAS or ARC (18.3 +/- 10.3; n = 70), and AIDS (20.7 +/- 10.3; n = 60). In addition, mean tear production was not decreased significantly when comparing each clinical group with the control subjects (17.8 +/- 4.4). However, the relative frequency of eyes with significantly decreased tear production (< 9 mm) was 23.6% in all 144 eyes. In addition, the relative frequency of significantly decreased tear production did not differ (P = 0.52) between eyes of patients with asymptomatic HIV infection (35.7%), LAS or ARC (21.4%), and AIDS (24.1%). In addition, the relative frequency of significantly decreased tear production did not differ (P = 0.30) between eyes of patients with a CD4+ count of more than 400 cells/microliters (23.1%; n = 26), 400 to 200 cells/microliters (31.3%; n = 48), 200 to 50 cells/microliters (14.3%; n = 42), and less than 50 cells/microliters (21.4%; n = 28).

CONCLUSION

The authors data show that decreased tear production occurs in approximately 20% to 25% of patients with HIV infection. This increased frequency of decreased tear production is not associated with the CD4+ count, or related to the severity of HIV disease, respectively. The possibility of an autoimmune-like pathogenesis of abnormalities of tear production in patients with HIV infection should be studied intensively.