Computer-assisted kinetic assay for quantification of total complement activity

Area of Science:

• Clinical chemistry
• Immunology
• Biophysical chemistry

Background:

• Complement activity assays are crucial for diagnosing immune deficiencies and monitoring treatment.
• Traditional methods can be time-consuming and require specialized expertise.
• There is a need for efficient, accurate, and accessible complement activity assays.

Purpose of the Study:

• To develop and validate a semiautomated kinetic technique for complement activity assay.
• To compare the performance of the new technique with a standard method.
• To assess the feasibility of the technique for routine laboratory application.

Main Methods:

• Hemolysis of sensitized red blood cells in a thermostated microflow cell connected to a spectrophotometer and computer.
• Computerized control, display, and analysis of assay phases.
• Comparison with Kabat and Mayer's method using 221 patient sera.

Main Results:

• High correlation (regression coefficient 0.94) between the new technique and the standard method.
• Similar results for samples with complement fraction deficiencies or in vitro activation.
• Excellent precision: coefficient of variation ~1% within series and <3% between series.
• High throughput: up to 30-40 samples per hour.

Conclusions:

• The semiautomated kinetic technique is a reliable and reproducible method for complement activity assay.
• The technique is user-friendly and suitable for routine, nonspecialized laboratories.
• This method offers an efficient alternative for assessing complement system function.