Research Focus: Use of IDK ELISAs to Detect Human AMP in the Intestinal Lumen

A study by Julie S. Hong, et al. from Weiner Lab at Columbia University investigated the application of enzyme-linked immunosorbent assays (ELISAs) to detect antimicrobial peptides (AMPs) in the human intestinal lumen. The study included human patients with Crohn’s disease who underwent a colectomy, and the team used a variety of Immundiagnostik ELISAs to detect human AMP in the intestinal lumen. These findings were presented at DDW 2024.

The study found that tracking intraluminal markers in ileal effluent from standard ileostomies may present a noninvasive way to detect the developing pathology within the intestinal grafts.

This could significantly improve current methods and bypass the need for invasive biopsies. This publication presents a solution to the current invasive techniques used to measure intestinal graft rejection.

A Non-Invasive Method to Detect Human AMP in the Intestinal Lumen

Intestinal transplantation is the treatment for intestinal failure but is often limited by high rates of rejection. There is a need for a reliable, noninvasive diagnosis for the treatment of rejection since the rejection episodes can occur many times over multiple years post-transplant.

The study’s novel approach focused on the role of antimicrobial peptides (AMPs) in mediating mucosal homeostasis in the intestine with luminal microbes. It was discovered that changes in these AMP levels in the intestinal Paneth cells are associated with intestinal graft rejection and Crohn’s disease.

The study’s groundbreaking hypothesis was that levels of AMP in ileal effluent could be associated with rejection, paving the way for a noninvasive technique to monitor rejection and serve as biomarkers for early detection. This type of measurement had not yet been explored in previous studies, making it a significant breakthrough. 

How the Researchers Measured Ileal Effluent

The study utilized ELISAs to measure a variety of biomarkers, including lysozyme, myeloperoxidase, calprotectin, and B defensin, in the ileal effluent. These ELISAs, although currently available, had not been adapted for use with ileal effluent. By assessing the levels of these biomarkers together in ileal fluid, the study proposed a noninvasive approach to determine rejection. The use of ELISAs in this context could provide a reliable, cost-effective method to assess levels of intestinal inflammation and gut homeostasis, potentially transforming the way rejection is diagnosed and managed. 

The Hong, et al. study presents a noninvasive technique to detect human AMP  in the intestinal lumen following transplant. These findings may provide a novel method to noninvasively diagnose and determine rejection of an intestinal implant.

You can read the full publication presented by Hong, et al. at Digestive Disease Week here.

The Use of Immundiagnostik Assays in the Study

The researchers used the IDK® Lysozyme, Calprotectin, MPO, and Beta-defensin 2 ELISAs to test the ileal effluent along with studies demonstrating that ELISAs are precise and replicable for ileal effluent through homogenization. The results showed that the ELISAs achieved consistent values of ileal effluent samples. Further efforts are needed to correlate the measurements obtained with clinical findings.