Researchers have created a new computer model that is able to show how the tiny slits in the spleen filter diseased or misshapen red blood cells from re-entering the bloodstream.

Led by Carnegie Mellon University President Subra Suresh and MIT Principal Research Scientist Ming Dao, the model is able to provide a tool that can study the spleen’s role in controlling disease that alter the shape of red blood cells and can be used to develop new diagnosis and therapeutics for a variety of acute and chronic diseases.

The spleen contains interendothelial slits, no larger than 1.2 micrometers tall, 4 micrometers wide and 1.9 micrometers deep. By passing through these tiny slits, healthy cells are filtered to deliver oxygen to the body's vital organs and diseased or misshapen cells are not able to pass through.

This study hoped to focus on observing the filtration process that goes on in the spleen, which has only been studied partly due to the small size of the slits.

Researchers have created a computer simulation based on dissipative particle dynamics to view these interendothelial slits and understand how they filter blood cells. Through the simulation, researchers were able to observe the variety of cells that pass through the slits, with the cells differing in size and shape. By observing the many different kinds of cells passing through the slits, researchers could see how only healthy blood cells were able to pass through the interendothelial slits.

"The computational and analytical models from this work, along with a variety of experimental observations, point to a more detailed picture of how the physiology of human spleen likely influences several key geometrical characteristics of red blood cells," Suresh said. "They also offer better understanding of how the circulatory bottleneck for the red blood cell in the spleen could affect a variety of acute and chronic disease states arising from hereditary disorders, human cancers and infectious diseases, with implications for therapeutic interventions and drug efficacy assays."

As well as giving researchers a view into the spleens filtration process, the model may provide insight into drug treatments for diseases that alter blood cell shapes such as malaria.