By Avigayil Kadesh
A study led by Israel Prize laureate Prof. Zvi Laron suggests that a virus contracted during pregnancy can damage the insulin-producing cells of the pancreas, laying the groundwork for Type 1 childhood diabetes (T1D) -- for which there is no cure -- and other autoimmune diseases.
As the incidence of T1D is rising worldwide, most research is focused on better treatment options. Laron proposes a radically new concept: preventing T1D by giving an antiviral vaccination to women of childbearing age.
“So many families have a diabetic child or have a family history of diabetes, and perhaps we can prevent it in future generations,” he says. “Having shown that other autoimmune diseases probably also start in utero – though they develop at different rates after birth -- maybe vaccinating for one disease will prevent others as well.”
Laron and researchers at the Tel Aviv University, University of Washington and Sweden’s Lund University tested 107 healthy pregnant women during winter months, when viral epidemics are more common. They looked for islet cell auto-antibodies (a sign of diabetes that appears years before initial symptoms show up) as well as anti-rotavirus and anti-CoxB3 antibodies.
Their recent paper published in
Diabetic Medicine describes finding specific antibodies, including those affecting the pancreatic cells responsible for producing insulin, in 10 percent of the test subjects. Antibody concentrations were even higher in cord-blood samples from their babies, implying an in-utero immune response by the fetus to the virus.
Same results in all countries tested
Laron is a professor emeritus of pediatric endocrinology at Tel Aviv University’s Sackler Faculty of Medicine, and director of the Endocrinology and Diabetes Research Unit at the Schneider Children's Medical Center. He won the 2009 Israel Prize for medical research for discovering Laron-type Dwarfism, a syndrome characterized by insensitivity to growth hormone.
He has been concerned over the rapidly growing prevalence of T1D, which occurs when the immune system mistakes the insulin-making islet cells of the pancreas for “enemies” and destroys them.
“I was in charge of the epidemiology of childhood diseases up to 1992,” says Laron. “When we looked at the seasonality of months of birth of children who developed diabetes up to age 18, we found this differs from the general population.”
To make sure this wasn’t just an Israeli phenomenon, Laron did collaborative studies in Sardinia, where T1D rates are high, as well as in Germany, Ireland, the United States and New Zealand. In both northern and southern hemispheres, the same pattern was observed.
Laron theorized that environmental factors, including viral infections contracted in utero, were to blame. And because there is a known association between T1D and other autoimmune diseases – for example, about 20 percent of T1D patients develop Hashimoto thyroiditis – he and his fellow researchers checked for, and found, the same seasonality of months of birth in children and adolescents with thyroiditis, celiac disease and multiple sclerosis.
Their latest study involving 107 women proved the seasonality hypothesis, but a larger sampling is needed to provide a stronger statistical basis.
“We need 900 women and we also need to find out if only one or more viruses are involved,” says Laron. “We are now looking for a source of about $40,000 so we can collect the samples of maternal blood and cord blood. We have about 10,000 deliveries in the Helen Schneider Women’s Hospital [in Petah Tikva] each year, and we could get the 900 women in a year or two.” A larger sum will be needed for the laboratory analysis.
The concept of vaccinating women with rotavirus has been patented, he says, but it is difficult to persuade the pharma industry to put dollars into this completely new approach that he believes could help large populations.
He emphasizes that viral infection triggers T1D only in genetically susceptible women and fetuses. Other women seem to have genes that protect against autoimmune diseases. But without expensive genetic testing, it is impossible to identify those who are most susceptible. Therefore he advocates vaccinating all women before they conceive.
“I think for a large portion of children who develop diabetes, this is why,” Laron says. “There could be many other factors, such as environmental toxins that damage the pancreas. But the incidence of childhood diabetes is increasing alarmingly, with no cure in sight. So true intervention would be important not only medically but also psychologically and financially, as the costs of the lifelong treatment of this chronic disease and other autoimmune diseases are great."