The Clinical Diagnostics Service of the Molecular Otolaryngology and Renal Research Laboratories is a CLIA-approved Joint Commission-accredited diagnostic laboratory.
Plasma Complement C4 Level
Dense Deposit Disease, C3 Glomerulonephritis and atypical Hemolytic Uremic Syndrome
Complement C4 (MW: 188 kDa), a central complement component in the classical and lectin pathways, is required to generate C4b2a, the C3 convertase of the classical pathway. C4 is cleaved to C4a (anaphylatoxin; 8 kDa) and C4b (180 kDa). C4b binds C2, and after removal of non-catalytic domain on C2, the C4b2a complex is formed. Unlike plasma C3, plasma C4 levels are typically normal in aHUS and C3G, however this test helps to rule out other complement-mediated renal diseases.
Indications for screening
Testing is appropriate for patients with aHUS, DDD, and C3GN
MORL screening methodology
Radial immunodiffusion (RID)
Turnaround time is ~ 2 weeks
1 ml frozen EDTA plasma (see testing requisition for specimen handling).
Cost & CPT Codes
See the MORL testing menu