It may be possible to slow the progression of type 1 diabetes, according to a new pilot study that used an experimental therapy that centers on the immune system.
In the new study, researchers in Sweden tested a new method to train the immune system to stop attacking the body's own insulin-producing cells, according to the findings published today (Feb. 15) in the New England Journal of Medicine. With only six participants, the study was small, but experts called these early results exciting.
In people with type I diabetes, the immune system mistakenly recognizes certain proteins in beta cellsas foreign invaders and wages a war against them. Once the beta cells have been killed, the pancreas produces little or no insulin, the hormone that regulates how the body absorbs sugar from the blood to use for energy. As a result, patients need to follow lifelong treatments ― such as insulin injections ― to keep their blood sugar levels at normal ranges. [9 Healthy Habits You Can Do in 1 Minute (Or Less)]
This destruction of beta cells doesn't happen overnight, however. Although the majority of them are gone by the time someone is diagnosed, some cells manage to dodge the attacks and continue to produce some insulin. That's why several research teams have been working on finding ways to rescue the remaining cells, or delay their destruction in people who have been recently diagnosed with the condition.
In the new study, the researchers injected a protein normally found on beta cells directly into the patients' lymph nodes.
"This method has shown the best efficacy so far," at slowing the disease's progression, said Dr. Johnny Ludvigsson, senior professor of pediatrics at Linköping University and the study's lead investigator. "But we have to be cautious. The number of patients is small."
If confirmed in larger trials, the therapy could bring a number of benefits to patients. The ability to make insulin secretion, even if only at very low levels, dramatically decreases people's risk of complications, such as episodes of dangerously low blood sugar levels, Ludvigsson told Live Science.
The small amount of insulin that the patients in the study could produce would also make it easier for the patients to maintain a good blood sugar balance, improving their quality of life. It would also reduce their risk of long-term complications of the disease, such as heart attack, stroke, neuropathy, kidney problems and eye disease.
"These are exciting results," said Dr. Lawrence Steinman, a professor of pediatrics and neurological sciences at Stanford University, who was not involved with the study. Steinman echoed Ludvigsson's warning that the study is small, and said that trials with more people and which include a control group of patients who are given a placebo are needed to confirm the findings.
How to make the immune system more tolerant
The injections that the researchers gave to the patients in the study contained a protein called GAD, which is normally found in the beta cells. Ludvigsson and his colleagues injected this protein into the patients' lymph nodes near the groin. Lymph nodes contain many immune cells, and the idea behind the treatment is that exposing the body's immune cells to larger amounts of GAD than they normally encounter will cause the immune cells to become more tolerant of GAD, and halt their attack on it.
The participants in the study were ages 20 to 22, and all had been diagnosed with type 1 diabetes within the last six months. The researchers followed up with the patients six to 15 months after the treatment, and found that the functioning of the pancreas had not declined, as expected in the typical course of the disease, but remained stable.
Previously, Ludvigsson's team had tried the same treatment, but had injected the protein under the skin. The new results suggest that an injection directly into the lymph nodes better exposes immune cells to the self-antigen.
"With a much lower dose, we got a very strong desired effect on the immune system," Ludvigsson said.
The team is now planning to repeat the study in a larger number of people, which would take a few years, Ludvigsson said.
Treating type 1 diabetes at the source
Although these results are far too early to be applied to patients, they lend promising evidence to a relatively new line of research that aims to modify the immune system with high precision to treat or perhaps even cure type 1 diabetes.
"A few approaches are in clinical trials, but nothing is yet on the market," Steinman said. "Antigen-based therapy [which was used in the new study] is a sought-after approach, but only a few in the world are attempting this."
In his own work, Steinman has focused on another protein, called proinsulin, which also becomes a target of the immune system in people with type 1 diabetes.
In a 2012 clinical trial with 80 people, Steinman and his team injected participants with a chunk of DNA-encoding proinsulin, in an attempt to desensitize the immune system to proinsulin. The researchers found that the function of the pancreas not only stabilized, but actually improved. It is possible, Steinman said, that some beta cells somehow hide from the immune attacks by going into hibernation, and that once the attacks are eased, they recover and resume function. Plans for the next trial are ongoing, Steinman said.
An immune therapy for type 1 diabetes in the future might combine some of the various approaches that different research teams have tried.
"So far, almost all studies have been performed testing one drug at a time, and they have not been effective enough," Ludvigsson said. "My opinion is that we need a combination of different approaches. For example, different drugs, given in a planned scheme, as is done in oncology. And not until just recently has that idea started to become accepted."
Originally published on Live Science.