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Factor I level

Lab Section:  Sendout Reference  
Lab Location:  Sendout
Reference Lab: ARUP 
Test ID: LAB2964 
Methodology: Radial Immunoassay
Schedule: Variable testing schedule
Reported: 4-5 weeks
Specimen Requirements:  Collection: 3.0 mL Blood in a Lavender Top Tube.
Pediatric volume: 1 mL.
Handling: Separate from cells within 30 minutes of collection.
Unacceptable conditions: Thawed specimens.
Stability: Ambient: Unacceptable; Refrigerated: Unacceptable: Frozen: 1 year


Clinical Indications: Complement factor I, also known as C3B/C4B inactivator, is a protein that in humans is encoded by the CFI gene. It is a protein of the complement system that regulates complement activation by cleaving cell-bound or fluid phase C3b and C4b. Factor I deficiency in turn leads to low levels of complement component 3 (C3) in plasma, due to unregulated activation of the complement alternative pathway, and it has been associated with recurrent bacterial infections in children; more recently, mutations in the Factor I gene have been shown to be implicated in development of Haemolytic Uremic Syndrome, a renal disease also caused by unregulated complement activation.

CPT Code(s): 86160
Last Changed: 12/26/2016 23:35:24
Last Reviewed: 12/26/2016 23:35:34