24-72 hours after setup at PeaceHealth Laboratories’ reference lab.
Specimen Collection Details
One 5 mL red top tube. DO NOT use gel barrier tube. Also acceptable: One 4 mL lavender top tube (EDTA).
Allow to clot, centrifuge and separate serum or plasma from cells into a plastic vial. Refigerate.
7 days ambient, 14 days refrigerated, or 2 months frozen.
1 mL serum or plasma.
0.5 mL serum or plasma.
Evaluate the classical complement pathway. C1q can be very low in hypocomplementemic urticarial vasculitis, severe combined immunodeficiency with agammaglobulinemia and x-linked hypogammaglobulinemia. C1q concentrations in patients with rheumatoid arthritis (RA) may be useful as a prognosticator of articular erosions.
Gel barrier tubes are not acceptable as they interfere with the assay methodology.