CH50 Level

CH50 measures total hemolytic activity of the classical and terminal pathways. CH50 can be low if complement components in the classical pathway (C1, C4, C2, C3) or terminal pathway (C5 through C9) are reduced or absent. Since most patients with C3G (especially DDD) have exceedingly low plasma C3 levels, their CH50s are also typically low.

CH50 is a screening assay of complement activity that uses an immunoassay system comprised in part of liposomes encapsulating glucose-6-phosphate dehydrogenase (G6PDH) to mimic an invading microorganism. With the addition of a serum sample, antibodies in the reagent attach to the surface of the liposomes and activate complement, with subsequent lyses. The released G6PDH reacts with glucose-6-phosphate and NAD, and changes the absorbance of the sample. This change is proportional to the complement activity in the sample

Indications for screening
CH50 is a screening test for many diseases associated with complement activation.

MORL screening methodology
Liposome-based immunoassay

Turnaround time
Turnaround time is ~2 weeks.

Sample Required
1 ml frozen serum (Red top, see testing requisition (page 3) for specimen handling).

Cost & CPT Codes

The Clinical Diagnostics Service of the Molecular Otolaryngology and Renal Research Laboratories is a Joint Commission-approved CLIA-accredited diagnostic laboratory.