Severity of Crohn's Disease Linked to Macrophage Identified in Blood Samples

Scientists from Lund University in Malmö, Sweden, have isolated and identified specific macrophages that affect the severity of Crohn’s disease, according to a study published in the Journal of Leukocyte Biology.

The researchers compared blood and intestinal biopsy samples from healthy individuals to samples from patients with Crohn’s disease. The blood monocytes were broken down into 3 groups: classical, intermediate, and non-classical. The intestinal macrophages, which are cells that destroy foreign substances, were also classified into 3 subsets: CD14hiHLA-DRdim, CD14hiHLA-Dbright, and CD14loHLA-DRint.

The samples were then purified using fluorescence-activated cell sorting techniques. The purified cells’ properties were observed to investigate the release of pro-inflammatory cytokines, matrix metalloproteinsases, and the ability of the monocytes to migrate toward CCL2.

The researchers noted the Crohn’s disease blood samples contained a higher amount of the CD14hiHLA-DRdim macrophage when compared to the healthy counterparts. They believe the CD14hiHLA-DRdim macrophage is most likely derived from pro-inflammatory classical blood monocytes. The scientists then suggested the CD14hiHLA-DRdim macrophage is the driving force behind the inflammation in Crohn’s disease, leading to intestinal tissue destruction.

“By increasing the knowledge on the different macrophage subsets in the intestine and their blood counterparts, we hope to contribute to the discovery of more specific targets in Crohn's disease, increasing the efficiency of new treatments,” study author Olof Grip, MD, PhD, said at a press conference.