blueberrymuffin said...
jenny, could you please share more info about it being an indicator?
C3a and C4a are split products of complement activation from the immune system. Each activates inflammation and stimulates smooth muscle spasm in small blood vessels, amongst other duties. C3a and C4a are typically both high in Lyme and other bacterial infections. C3a is low or low normal, and C4a is high 99% of the time in other biotoxin illnesses, most commonly in mold toxin illness.