MedWire News: Study results show that evidence of enteroviral infection is most common in pancreatic islets from patients with Type 1 diabetes, but is also found in some islets of patients with Type 2 diabetes.
“Enteroviral infection has long been implicated in triggering autoimmunity, islet inflammation (insulitis), and beta cell death in human Type 1 diabetes,” say Noel Morgan (Peninsula Medical School, Plymouth, UK) and colleagues.
However, much of the evidence to date is circumstantial and less is known about potential links with Type 2 diabetes.
The team assessed the prevalence of enteroviral capsid protein vp1 (vp1) staining in pancreatic autopsy samples from 72 recent-onset Type 1 diabetes patients, aged 12.6 years on average, and 161 control individuals. The control samples included 25 taken from adult patients with Type 2 diabetes.
The pancreatic samples were also immunostained for insulin, glucagon, double-stranded RNA activated protein kinase R (PKR), and MHC class I.
As reported in the journal Diabetologia, the researchers found that 44 out of 72 of the Type 1 diabetic samples had evidence of vp1 immunopositivity in multiple islets compared with in three out of 50 normal neonatal and pediatric control samples, in three islets each.
Ten pancreatic samples from the 25 Type 2 diabetes patients also had vp1 immunopositivity in various islets.
PKR production correlated strongly with vp1 positivity, consistent with a persistent viral infection of the islets.
Morgan commented: “We are genuinely excited by the findings of our study. This is the first time that scientists have been able to provide such extensive evidence for the relationship between enteroviral infection of the beta cells and the development of Type 1 diabetes.”
He concluded: “The next stages of research – to identify which enteroviruses are involved, how the beta cells are changed by infection and the ultimate goal to develop an effective vaccine – will lead to findings which we hope will drastically reduce the number of people around the world who develop Type 1 diabetes, and potentially Type 2 diabetes as well.”
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