Type 1 diabetes is often described as a condition in which the body fails to produce the hormone insulin. New research, however, provides further evidence that not all insulin production is lost with the condition, and this may be down to an anti-inflammatory protein.
Researchers from Uppsala University in Sweden found that nearly half of patients who had been living with diabetes for more than 10 years produced some insulin.
What is more, these insulin-producing patients also had higher blood levels of immune cells that produce a protein called interleukin-35 (IL-35), which is believed to suppress the immune system and reduce inflammation.
Study co-author Dr. Daniel Espes, of the Department of Medical Cell Biology at Uppsala University, and colleagues recently reported their findings in the journal Diabetes Care.
Type 1 diabetes is estimated to affect around 1.25 million children and adults in the United States. The condition arises when the immune system mistakingly attacks the insulin-producing cells, or beta cells, of the pancreas.
It was once thought that patients with type 1 diabetes experienced a complete loss of insulin production, but increasingly, studies have indicated that some patients still possess functioning beta cells.
For this latest study, Dr. Espes and colleagues set out to determine whether there are any immunological mechanisms that might explain why some patients with type 1 diabetes still produce some insulin.
The research included 113 patients with type 1 diabetes who were aged 18 and older. All patients had been living with the condition for at least 10 years.
Using the ultra-sensitive ELISA test, the researchers measured the levels of C-peptide in the patients’ blood, which is an indicator of insulin production.
Additionally, the researchers measured levels of circulating cytokines among the patients, including IL-35. Cytokines are proteins secreted by immune cells that play a key role in cell signaling.
The team found that almost half of patients with type 1 diabetes were C-peptide-positive, meaning that they had some level of insulin production.
The results also revealed that patients who were C-peptide-positive had significantly higher levels of IL-35 in their blood, compared with patients who were C-peptide negative – that is, those who had lost all insulin production.