• Detecting deficiencies in the alternative pathway that can cause atypical-hemolytic uremic syndrome, dense deposit disease, and C3 glomerulonephritis
• A second-order test that aids in the differential diagnosis of thrombotic microangiopathies

• Fasting preferred

  •  Fasting for a blood test

• Samples should not be collected earlier than 48 hours following plasma exchange

Lt blue Sodium citrate (NaCit)

Red serum vial/tube, 5 mL

• Samples should not be drawn earlier than 48 hours following plasma exchange
• Immediatley following collection, mix sample by gentle inversion 3 - 4 times to prevent clotting
• Place sample on ice

1. Allow serum sample to clot
2. Spin cold
3. Transfer serum and plasma to two (2) Screw cap transfer vial/tubes (Mayo T914)
4. Freeze within 30 minutes

Two (2) Screw cap transfer vial/tube (Mayo T914) (2), labeled as serum and Na cit plasma

Frozen (strict) - 14 days

• Gel separator/SST tubes are not acceptable

C3HUS, C4HUS, FBCA, FHCA, C5AG2: Nephelometry

COM3: Automated Liposome Lysis Assay

AH503, C4D, CBB, SC5B9: Enzyme-Linked Immunosorbent Assay (ELISA)

An interpretive report will be included

Factor B complement Ag:                                     15.2-42.3 mg/dL
SC5b-9 complement:                                                  ≤250 ng/mL
Factor H complement Ag:                                     18.5-40.8 mg/dL
C4d complement activation fragment:                          ≤9.8 μg/mL
CBb complement activation fragment:                          ≤1.6 μg/mL
Complement C4:                                                        14-40 mg/dL
Complement C3:                                                       75-175 mg/dL
Complement, alternate pathway (AH50), functional:      ≥46% normal
Complement, total:                                                      30-75 U/mL

Reference values have not been established for patients who are <16 years of age.