Complement Factor I Level Assay

Atypical Hemolytic Uremic Syndrome 
Complement Factor I (FI; MW: 88 kDa) is an important regulator of complement activity triggered through the classical and alternative pathways. FI limits complement activation by cleaving surface-bound and fluid-phase C3b and C4b, preventing the assembly of the C3 and C5 convertases. Patients with FI mutations may have reduced plasma FI levels and/or function, and are at-risk to develop atypical hemolytic uremic syndrome or C3 glomerulopathy.

Indications for screening 
Testing is appropriate for patients with aHUS.

MORL screening methodology 
Enzyme Linked Immuno-Sorbent Assay (ELISA)

Turnaround time 
Turnaround time is ~2 weeks.

Sample Required 
1 ml frozen EDTA plasma (see testing requisition for specimen handling).

Cost & CPT Codes

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