MORL Screening Methodology
Enzyme linked immunosorbent assay (ELISA)
Sample Requirements
- 1ml frozen serum
Sample Stability
- Serum samples must be frozen to below -80°C immediately after separation from cells and shipped on dry ice. These samples remain viable for at least six months when stored at -80°C.
Shipping Requirements
- All serum samples MUST be processed and frozen down to -80°C immediately after collection
- Labeled with the sample type AND patient’s name, DOB, MRN and sex
- Cryovials should be put in zip lock bags and completely covered in dry ice to keep the sample frozen until it arrives in the lab
- Shipped overnight on at least 5 lbs of dry ice
- Shipping and receiving dock closed on weekends and holidays
- Deliveries accepted Monday - Friday
If samples arrive thawed they will be REJECTED.
Indications for Testing
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).
Quick Facts
- CPT code: 83516
- Test code: 07FHAA
- Turnaround time: 4 weeks
- Cost: $356
Background Information
Factor H autoantibodies (FHAAs) compromise FH function targeting various domains of the factor H protein.
Approximately 10% of patients diagnosed with atypical hemolytic uremic syndrome/complement-mediated TMA have FHAAs (Dragon-Durey et al., 2005; Moore et al., 2010). It is noteworthy that most persons developing FHAAs are homozygous for a specific copy number variation, the deletion of two genes, CFHR3 and CFHR1. The presence of FHAAs usually compromises function of the C-terminal region of factor H, impeding its surface regulatory function (Józsi et al., 2007).
FHAAs are also identified in ~3% of patients with C3 glomerulopathy and infrequently in persons with monoclonal gammopathy of renal significance (MGRS) (Zhang, et al., 2020).
The diverse clinical manifestations associated with FHAA-mediated diseases reflect both the intricacies of factor H and the epitope specificity of FHAA targeting select regions of the factor H protein.
The Clinical Diagnostics Service of the Molecular Otolaryngology & Renal Research Laboratories is a CLIA-approved, Joint Commission-accredited diagnostic laboratory.