Ex Vivo Test for Measuring Complement Attack on Endothelial Cells: From Research to Bedside

Area of Science:

• Immunology
• Pathophysiology

Background:

• The complement system, part of innate immunity, defends against pathogens but can cause self-damage when dysregulated.
• Endothelial cells are primary targets of complement overactivation, implicated in numerous human diseases.
• Current diagnostic methods for complement dysregulation are limited, especially for localized tissue activation.

Purpose of the Study:

• To review diseases where endothelial cell assays have been used to detect complement overactivation.
• To compare endothelial cell assays with other available tests for complement dysregulation.
• To discuss challenges and unanswered questions for validating these assays in clinical practice.

Main Methods:

• Analysis of complement deposits on cultured endothelial cells incubated with patient serum.
• Review of existing literature on endothelial assays in various diseases.
• Comparison of endothelial assays with other diagnostic tools for complement overactivation.

Main Results:

• Endothelial cell assays have been applied to diverse conditions including atypical hemolytic uremic syndrome, malignant hypertension, and pre-eclampsia.
• These assays can inform therapeutic adjustments for complement-blocking drugs in some cases.
• The ex vivo endothelial cell assay closely mimics physiological conditions for studying complement activation.

Conclusions:

• Endothelial cell assays offer a promising approach to diagnose complement-mediated diseases, especially when plasma markers are normal.
• Further standardization and mechanistic understanding are crucial for widespread clinical adoption.
• Addressing challenges in primary cell culture and assay validation is essential for routine use.