Viral infections and type 1 diabetes mellitus – guilty viruses in the court of autoimmunity

Abstract

Type 1 diabetes mellitus (T1D), previously known as insulin-dependent or juvenile diabetes, is a chronic disease characterized by an autoimmune-induced pancreatic damage resulting in the destruction of beta cells. Although less common than type 2 diabetes mellitus, acute and life-threatening complications such as diabetic ketoacidosis maybe fatal and mostly develop in children and teenagers. Prevention methods are not fully clear, but maintaining a healthy lifestyle is crucial as adjunctive to therapy. Treating type 1 DM is challenging particularly as the disease is not curable, and heavily depends on the individual patient, strict insulin regimens to maintain glucose levels under control. While T1D has a multifactorial background including several genes and environmental factors; various infections mainly viruses are a leading environmental trigger of the disease. The strong correlation between infections and T1D, is a vivid proof of a historical bond between infection and autoimmunity. This review focuses on viruses, a factor strongly associated with the development of T1D, including Group B Coxsackie Virus (CVB), Rubella, Epstein Barr Virus (EBV) and recently the SARS-CoV-2 (COVID-19). Two proposed mechanisms in which viruses might possibly trigger T1D is either through direct damage led by viral persistence or through excessive activation of cytokines aimed initially to stop viral replication nevertheless may cause cellular damage.