Collect Red Top or SST, spin, separate and send 1 mL serum refrigerated. If collecting SST serum must be removed from gel within 1 hour of collection.
Room Temp: 4 days, Refrigerated: 10 days, Frozen: 29 days
4-6 days, Performed: Monday, Wednesday
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.