Complement, CH50

Total Complement (CH50)

Alternate Test Name

Total Complement; Complement Total (CH50), Serum

Epic Mnemonic
Sunquest Mnemonic

LAB154
CH50

Category

Sendouts

Methodology

Liposome Immunoassay (The Binding Site SPAPLUSAnalyzer)

Test Performance Schedule

Tuesday, Thursday

Result Availability

2-5 days

Container

Red top (serum) tube

Volume

Pref. Vol.: 6 mL
Min. Vol.: 2 mL

Collection Instructions

• Routine venipuncture
• Immediately after collection, gently invert tube 5-10 times
• Place the tube on wet ice
• Clot 30 minutes
• Promptly centrifuge for 15 minutes
• Transfer to plastic tube
• Freeze within 1 hour of collection

Transportation Instructions

Frozen

Stability

After separation from cells:
• Room temperature: Unacceptable
• Refrigerated: Unacceptable
• Frozen: 14 days

Causes for Rejection

• Not frozen within 1 hour of collection
• Serum gel tube

Remarks

Fasting preferred

CPT Codes

86162

Effective/Revised

5/1/2023

Total Complement (CH50) is a functional assay that measures the activity of complement components C1 to C9 (i.e., the classical and terminal pathways). It doesnotmeasure the functional activity of the alternative pathway. If the Total Complement (CH50) measurementis zero or very low it is advisable to repeat the test to confirm the result. If the result is confirmed, the clinical presentation should be considered prior to further testing. If the patient exhibitsrecurrent neisserial infection, immunochemical determination of C5, C6, C7 and C8 is advised (or a functional assay for C5-C8). If the clinical problem isangioedema,initial studies should include C3, C4, C1 inhibitor (and possibly C1q and C2). Acquired disorders such as immune-mediated glomerulonephritis and other autoimmune disorders should direct testing towards C3 and C4.