Pemphigoid Gestationis, Complement-Fixing Basement Membrane Antibodies (Herpes Gestationis Factor)

Also known as: HG FACTOR

Clinical Use

Use

This test is primarily used as the preferred panel to assess and monitor pemphigoid gestationis (also known as herpes gestationis) and other immunobullous diseases characterized by complement-fixing basement membrane zone antibodies. This specific immunodermatology serum test is performed to detect complement-fixing (herpes gestationis factor) and noncomplement-fixing IgG basement membrane zone antibodies. The presence of these antibodies supports the diagnosis of pemphigoid gestationis, a rare autoimmune blistering disorder occurring in pregnancy. The test leverages a combination of Semi-Quantitative Complement Fixation, Indirect Immunofluorescence, and Semi-Quantitative Enzyme-Linked Immunosorbent Assay (ELISA) methodologies for thorough identification and quantification.

Special Instructions

Not provided.

Limitations

The test is performed by a non-ARUP laboratory and its methodologies, although developed and performance characteristics determined by the Immunodermatology Laboratory at the University of Utah, have not been cleared or approved by the FDA, as FDA approval is not required for tests conducted in a CLIA-certified laboratory. Despite thorough testing procedures, results do not rule out other immunobullous diseases and should be considered alongside clinical findings and additional diagnostic insights. Results may vary with disease activity and specimen characteristics, such as severe hemolysis or lipemia.

Test Details

New York Approved

Methodology

Immunoassay (IIF)

Biomarkers

3 components

Semi-Quantitative Complement Fixation • IIFIndirect Immunofluorescence • IIFSemi-Quantitative Enzyme-Linked Immunosorbent Assay (ELISA) • ELISA

LOINC Codes

Result Codes

45179-9 - HG IgG CF Ser Ql IF

Result Turnaround Time

7-14 days

Specimen

Serum

Volume

2 mL

Minimum Volume

1 mL

Container

ARUP standard transport tube

Collection Instructions

Collect in a plain red or serum separator tube (SST).

Storage Instructions

Store refrigerated unless shipping promptly (within 2 hours). Transport at ambient temperature to arrive within 7 days. If 7-14 days until received in laboratory, store and ship refrigerated. If greater than 14 days, serum specimens must be stored and shipped frozen.