Related Experiment Videos
Cold-dependent activation of complement: recognition, assessment, and mechanism.
K P Mathews1, R A Mentyka, S L Chambers
1Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, California 92037.
Journal of Clinical Immunology
|September 1, 1992
Summary
Cold-dependent activation of complement (CDAC) causes low hemolytic activity in chilled serum. This study identifies aggregated IgG as the likely cause of CDAC, aiding in understanding this rare immune phenomenon.
Area of Science:
- Immunology
- Clinical Chemistry
Background:
- Cold-dependent activation of complement (CDAC) is a rare phenomenon causing low hemolytic complement activity in chilled serum.
- Unfamiliarity with CDAC can lead to diagnostic confusion and unnecessary laboratory testing among clinicians.
Observation:
- A patient presented with complement test abnormalities consistent with CDAC.
- Evidence of classical complement pathway activation in the cold was confirmed through multiple assays, including C4, C3a, and C4d generation.
Findings:
- CDAC activity persisted for over five years and was temperature-dependent (greater at 13°C than 4°C).
- Activation was abolished by heating serum at 56°C and could be restored by adding C1.
- Aggregated immunoglobulin G (IgG) was identified as the probable cause of CDAC.
Implications:
- Understanding CDAC can prevent misdiagnosis and unnecessary tests.
- Identifying aggregated IgG as the cause provides a target for further research and potential therapeutic strategies.
- This research highlights the importance of considering CDAC in patients with unexplained complement abnormalities.