METHODS FOR ASSESSING COMPLEMENT ACTIVATION LEVELS 

To ensure accurate and standardized results, complement analysis requires precise sampling techniques and assay procedures. There are various approaches to measure complement activation and function. Hemolytic assays, used for functional assessment of the complement cascade in vitro, have, to a high degree, been replaced by standardized assay formats, such as the Wieslab® Complement Assays. These assays allow for automation and are able to assess complement activation and function via the individual complement pathways without the inherent variability of erythrocyte-based assays.

Another way of assessing complement function is through complement-induced receptor signaling. This method measures downstream signaling events when complement proteins bind to their specific receptors. Cell-based assays have emerged as valuable tools since they reflect the biological relevance of the assayed biomarker or drug.

An alternative to functional assays is the use of enzyme-linked immunosorbent assay (ELISA) to measure individual complement proteins and activation products. Careful selection of such biomarker assays provides functional insights into complement activation, allowing detection of in vivo complement activation. These assays are also useful tools in the development of biomaterials and pharmaceuticals, as they can assist in assessing biocompatibility, key break-off points, and retained complement activity or inhibition in specific parts of the complement cascade.

Collectively, these methods offer a comprehensive assessment of complement activation, aiding in the understanding of disease progression and treatment efficacy.