Colonoscopies can be an uncomfortable procedure for patients, which may be a barrier to diagnosis with ulcerative colitis. Now, researchers at the Institute for Biomedical Sciences at Georgia State University have developed a blood test which uses infrared spectroscopy to screen patients for this type of inflammatory bowel disease (IBD).
The researchers believe that this technique could lead to faster and cheaper diagnoses, and may reduce our reliance on colonoscopies. Their findings were published in the Journal of Biophotonics.
In their study, the team analyzed blood samples collected from mouse models of ulcerative colitis using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy. They found that the readout produced nine absorption peaks that could be used as diagnostic indicators of IBD.
It’s estimated that over 1.6 million individuals in the US suffer from IBD, which causes inflammation in the large intestine. Regular colonoscopies are recommended for people over the age of 50, however the preparation for the procedure – and the procedure itself – is unpleasant for patients.
In addition, colonoscopies often require the patient to be sedated, adding to the cost and potential complications of the procedure. A simpler, blood-based diagnostic for IBD could help to address these issues, according to the researchers.
“Colonoscopy is used as a screening technique, so even if you don’t know if a person has colitis or not, that’s currently the only way to clearly check and say they do,” said Dr. A. G. Unil Perera, Regents’ Professor of Physics. “We are not talking about replacing colonoscopy.
“We have shown that a minimally invasive blood test can tell if a patient has an indication of colitis. Then, doctors can perform a colonoscopy to see how far the disease has spread and whether there are signs of cancer.”
Since colonoscopies are also an important tool in screening for ulcers and both benign and cancerous polyps, Perera’s assertion that the blood test would not replace the technique is important. However, a colitis blood test could help rule out the inflammatory condition when diagnosing gastrointestinal issues.
In their study, the researchers used two groups of mice with chronic and acute forms of colitis. Mice with chronic colitis were bred with a gene mutation that makes them susceptible to developing IBD. In comparison, another group of mice were fed a chemical known as Dextran Sodium Sulphate (DSS) which induced acute colitis over time. Baseline blood samples taken from the second group of mice before they were administered DSS were used as a control.
Using the ATR-FTIR spectroscopy, Perera and colleagues studied blood samples collected from the acute and chronic colitis mouse models. They compared the readouts to those from the control samples in order to identify any differences that could be an indicator of colitis.
“We have identified nine places where there are differences,” said Perera.
Future studies conducted by the research team will include a larger sample size in an attempt to confirm the findings and potentially narrow down the important differences. The researchers also say that in the future, the blood test may help clinicians differentiate between different types of IBD, such as ulcerative colitis versus Crohn’s disease.
“We can design detectors for only the narrow peaks that we really need,” said Perera. “That way a doctor’s office should be able to afford the test and add it to existing blood tests, since people usually don’t worry too much about giving a little bit of blood.
“Around the world, this is even more critical because colonoscopy is very, very expensive and people may not have access. This technique can also lead to other applications, like screening for cancer and other diseases.”