Diarrhea-predominant irritable bowel syndrome (IBS-D) may be associated with immune system exhaustion, according to researchers from the University of Adelaide and the South Australian Health and Medical Research Institute (SAHMRI). Their results are published in the journal Gut.
Researchers enrolled 11 subjects (10 female; mean age: 59 years) with long standing IBS that was characterized via ROME II criteria. Five had IBS-D, four IBS-A, 2 IBS-C. All subjects were followed for 1 year, and researchers compared blood samples taken during periods when patients experienced symptoms to those taken when patients were symptom free.
All IBS-D patients had the same kind of exhaustion in their T-cells.
Previous studies have documented the link between IBS and stress, and the immune system can be inhibited by cortisol and stress hormones. This is the first study to document T-cell exhaustion in IBS-D patients.
"For the first time, we've discovered that in patients with IBS-D, their T-cells seem to be 'out of puff' or run down," said lead researcher Patrick Hughes, MD, senior lecturer, Adelaide Medical School, University of Adelaide, and member, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia.
"These normally active immune cells are less responsive to stimulation, secreting fewer mediators and dividing less. This type of response is often observed in chronic infections,” he added.
"Irritable bowel syndrome takes a real toll on patients," said Dr, Hughes. "It can affect people in the prime of their lives, it's a chronic disease that can last a long time, and the treatments currently available are poor. Anything we can do to better understand the disease and to help reduce its debilitating effects on patients will be welcome," he concluded.
This research was supported by the National Health and Medical Research Council (NHMRC).