Red blood cells might reveal an unexpected warning sign that the liver is under strain.
Researchers at The University of Toledo have discovered that these cells behave differently when bile acids accumulate in the bloodstream, potentially offering a quick way to detect hidden liver issues.
Liver disease is often hard to diagnose early since the organ can keep functioning even after damage begins. Many individuals don’t notice clear symptoms until the condition has worsened.
The liver handles hundreds of vital tasks, including producing bile, a digestive fluid that breaks down fats and helps the body absorb vitamins like A, D, E, and K.
Bile contains substances called bile acids. Normally, after production in the liver, these acids travel through the bile system and intestine, where most are recycled back to the liver.
When this process is interrupted, bile acids can leak into the bloodstream, especially if the liver is injured or bile flow is blocked.
Elevated bile acids in the blood are known as cholemia. The tricky part is that many people can have high levels without feeling sick, particularly in the early stages of liver problems.
Standard blood tests don’t routinely measure bile acids. Instead, doctors look at liver enzymes, bilirubin, and other markers to assess liver health.
While these tests are useful, scientists believe bile acids can rise before typical warning signs appear. This suggests doctors might be missing an early opportunity to identify liver issues.
Dr. Matam Vijay-Kumar and Sadhana Kumari from The University of Toledo found a potential new way to indirectly detect high bile acid levels, focusing on red blood cells instead of the liver itself.
Red blood cells have flexible outer membranes that allow them to pass through tiny blood vessels. The scientists predicted that bile acids might weaken these membranes and cause cells to rupture more easily.
Contrary to expectations, the experiment showed that red blood cells exposed to high bile acid levels became tougher to break apart.
The team first observed this effect in several mouse strains that naturally had elevated bile acids. They then tested whether the same pattern existed in humans with liver disease.
The human study involved 23 patients with cholestatic liver disease at the University of Toledo Medical Center. Their blood samples were compared to those from 23 healthy individuals of similar age and sex.
In both groups, red blood cells from patients with high bile acids showed increased resistance to osmotic stress, providing a measurable difference that could be used for rapid screening.
Further analysis revealed that exposure to high bile acids altered the fats in the red blood cell membrane, increasing cholesterol while decreasing phospholipids—key components of the membrane structure.
This imbalance made the membranes more rigid, which likely explains the cells’ altered response in laboratory tests.
The proposed screening method would require only a tiny blood sample—around four microliters—that could be mixed with a special solution. Results might be available within 10 to 20 minutes.
If validated in larger studies, this approach could be a convenient addition to routine health screenings. It could be performed alongside standard blood tests, using one small extra sample.
The researchers emphasize that this test would serve as a screening tool, not a definitive diagnosis. An abnormal result would prompt further investigation into liver and bile system health.
This distinction matters because elevated bile acids can stem from various causes, including fatty liver disease, bile duct obstruction, or medication effects. The test wouldn’t specify the exact condition but would indicate the need for more tests.
One promising application is during pregnancy, where intrahepatic cholestasis can cause bile acids to rise and pose risks to the baby. Rapid detection could help clinicians decide who requires closer monitoring or more in-depth testing.
The findings, published in the American Journal of Physiology—Gastrointestinal and Liver Physiology, are currently preliminary. The University of Toledo has filed a patent application for this rapid testing method.
The approach highlights an elegant simplicity: instead of measuring bile acids directly with complex lab tests, scientists observe how a small blood sample behaves under controlled conditions, potentially making early screening faster and easier.
However, the evidence is still early. The study involved only 23 patients with liver disease and 23 healthy controls, which is too small to determine the test’s accuracy in the general population.
Other illnesses might also influence red blood cell membranes, so future research is needed to see if such conditions could lead to false results. Determining the best threshold for abnormality is also essential.
Moreover, it remains to be established whether routine screening for bile acids would lead to earlier treatment and improved health outcomes—detecting a biological change is only beneficial if follow-up actions and interventions improve patient health.
Overall, this innovative approach offers a promising way to detect early, often invisible signs of liver stress. If larger studies confirm its reliability, the behavior of everyday red blood cells might become a valuable early indicator for liver health assessment.
Source: The University of Toledo.
