Advanced Diagnostic Laboratories

Factor H Autoantibody

Test Code

FHAB

Description

The complement system is part of our innate immune response. It is vital to our defense against invasive microorganisms. Complement activation can occur through the classical, lectin and alternative pathway, which then converge to a common terminal pathway. Complement activation is controlled by multiple proteins at various steps in each pathway to prevent injury to autologous tissues. Factor H is the key regulator of the complement alternative pathway.

The Factor H autoantibody assay is a sensitive method for detection of autoantibodies directed against Factor H. FH autoantibodies that interfere with the function of FH can lead to complement dysregulation and systemic chronic inflammation. FH autoantibody has been associated with the pathogenesis of several disease such as complement C3 glomerulopathy (C3G), membranoproliferative glomerulonephritis and atypical hemolytic uremic syndrome (aHUS).

Collect

Serum from a Red top tube is the only acceptable sample type. Draw blood into a serum collection tube. The collection tube should be completely filled with blood. Invert tube several times to initiate the clotting process. Keep the tube filled with blood at room temperature for 30-60 minutes to allow the blood to clot.
Ensure that the blood is centrifuged within 60 (± 5) minutes of collection

Patient Prep

Centrifuge the collection tube at 1600 (± 200) x g (rcf) at 4°C (± 2°C) for 15 (±1) minutes. Affix tube label to a polypropylene cryogenic storage tube. Immediately transfer the cell-free serum to the cryogenic tube on ice and immediately store the cryogenic tube at -60°C or below in an ultra-low freezer.
Preferred volume: 1.0 mL serum
Minimum volume: 0.25 mL serum

Pediatric Collection

Minimum volume: 0.25 mL serum

Unacceptable Conditions

Thawed samples or samples stored at room temperature prior to shipment.

Storage Transport Temp

Ship samples overnight in a well-insulated container on dry ice. We receive samples Monday - Friday. Avoid sending samples on the weekend and holidays to ensure that samples arrive frozen.

Stability

-60°C or below in an ultra-low freezer - up to 2 years

Notes

Additional tests may be needed for confirmatory testing or reflex testing.
To prevent unnecessary delays in testing, please send one aliquot per test request.

Performed

Monday - Friday

Methodology

Enzyme-linked immunosorbent assay (ELISA)

Turnaround Time

Up to 4 weeks

Department

Complement Lab

Synonyms

Complement Factor H autoantibody, Factor H autoantibody, anti-FH Antibody, FHAB

Study Offerings

CAP/CLIA

Related Tests

If aHUS (aka Complement related HUS) is suspected, the full C3GN panel (Test Code: C3GN) should be considered.