Assessment of complement activity is essential in the diagnosis of many diseases. Jeroen Bosch Ziekenhuis (JBZ) in Hertogenbosch, The Netherlands, was using a hemolytic based test for assessment of the classical and alternative complement pathways. However, these tests were associated with some drawbacks such as:

• Need for large sample volumes is a problem especially with pediatric patients
• The test is labor intensive
• The hemolytic test system is difficult to standardize and is associated with stability/quality issues regarding the erythrocytes used in the assay

The scope of this study was to investigate whether the Complement System Screen (product code COMPL 300) may be an alternative to the hemolytic based testing for assessment of complement activity.