One of the major effects of CIRS in response to exposure to water-damaged buildings, is a significant elevation of the levels of C4A, a split product of complement C4 protein, a protein of the immune system. Often genetically susceptible patients with CIRS, who have had exposure to a seriously water-damaged building will have C4A levels greater than 10,000 ng/ml.
C4A testing should be performed by National Jewish Laboratories in Denver. Neither Quest or LabCorp are currently sending C4A blood samples to that laboratory so other alternatives such as Open Medicine Institute (OMI) and the mobile Iggbo service are being looked into.
Significantly elevated C4A levels effect the body by two major mechanisms:
- By impairing capillary perfusion leading to fatigue, muscle pain and impaired exercise tolerance
- By imbalancing the glutamine/glutamate ratios in nerve cells leading to the following cognitive symptoms
- Impaired memory
- Impaired concentration
- Decreased assimilation of new information
- Impaired word finding
C4A levels can be reduced using erythropoietin (Procrit) injections, however many physicians are not using this due to the black box warnings on the product. In this case, VIP nasal spray is the only proven option for reducing C4A. Cholestyramine and removal from exposure from water-damaged buildings may also assist with reducing C4A levels.