FH Autoantibody Dense Deposit Disease
Label Mnemonic: FHDDD
Epic Lab Code: LAB7432
Downtime Form: A-1a Miscellaneous Request
Commercial Mail-out Laboratory
5231 RCP
356-8593
Specimen(s):
Whole Blood
Collection Medium:
Red top tube 5 mL (Clot Activator)
Minimum:
Preferred Minimum: 1 mL serum from whole blood
Absolute Minimum: 0.5 mL serum from whole blood
Turn Around Time:
2 weeks upon receipt at reference laboratory
Reference Range:
Normal: <200 AU
Reported as negative or positive
Interpretive Data:
Factor H Autoantibodies
Dense Deposit Disease (DDD, aka Membranoproliferative Glomerulonephritis Type II, MPGNII)
Factor H autoantibodies have been associated with DDD (Meri et al., 1992). In patients with DDD, these autoantibodies bind to and block the N-terminal region of the Factor H protein, which compromises its fluid- phase regulatory function.

Atypical Hemolytic-Uremic Syndrome
Factor H autoantibodies are identified in ~10% patients with aHUS (Dragon-Durey, et al 2005, Moore, et al 2010). Most but not all patients with aHUS who develop Factor H autoantibodies are homozygous for a known polymorphism, del(CFHR3-CFHR1). Homozygosity for this deletion is seen in 15% of patients with aHUS as compared to 5% of controls of northern European ancestry (Zipfel et al 2007, Skerka et al 2009). The Factor H autoantibodies in aHUS patients bind to and block the C-terminal region of the Factor H protein, which interferes with its surface regulatory function (Józsi et al 2007).

Sensitivity >99%
Comments:
Please print, complete and submit the Kidney Testing Requisition Form from the Molecular Otolaryngology & Renal Research Laboratory, to Specimen Control/Mailouts with the specimen and the Epic Requisition.
Methodology:
Enzyme Linked Immuno-Sorbent Assay (ELISA) is used to assay the presence of Factor H autoantibodies.
CPT Code:
83516