Test Code PLA2I Phospholipase A2 Receptor, Immunofluorescence, Serum
Ordering Guidance
This test can be used in a complementary fashion with a quantitative enzyme-linked immunosorbent assay to confirm a positive result, especially if it is a low-level titer. Since the immunofluorescence is more sensitive, it can also be used to detect or follow patients with low level antibodies not detected by ELISA. Â
Specimen Required
Supplies: Sarstedt Aliquot Tube 5 mL (T914)
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial within 2 hours of collection.
Useful For
Distinguishing primary from secondary membranous nephropathy in patients with low levels of anti-phospholipase A2 receptor (PLA2R) antibodies
Screening for anti-PLA2R antibodies
Monitoring patients with membranous nephropathy at very low antibody titers
Method Name
Indirect Immunofluorescence Assay (IFA)
Reporting Name
PLA2R, Immunofluorescence, SSpecimen Type
SerumSpecimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 14 days | |
Frozen | 14 days | ||
Ambient | 8 hours |
Reject Due To
Gross hemolysis | Reject |
Gross lipemia | OK |
Clinical Information
Membranous nephropathy (MN) is a rare disease in which immune complexes deposit at the glomerular basement membrane, causing damage to the filtration barrier, resulting in proteinuria. Recent studies have shown that in approximately 70% of patients with primary MN (pMN), the immune complexes consist of autoantibodies against the podocyte protein M-type phospholipase A2 receptor (PLA2R).(1) There is also evidence that levels of anti-PLA2R autoantibodies correlate well with disease activity and progression.(2) The presence of anti-PLA2R antibodies could also potentially be used to differentiate pMN from other causes of nephrotic syndrome if a biopsy is not possible. Among patients with chronic kidney disease (CKD) awaiting kidney transplantation, higher levels of anti-PLA2R could predict those more likely to recur after transplantation.(2) Mayo Clinic Laboratory data suggest that there is a high concordance between the enzyme-linked immunosorbent assay and indirect immunofluorescence assay (IFA) PLA2R results, although the IFA may be more sensitive in monitoring patients with membranous nephropathy with very low antibody titers.
Reference Values
Negative
Interpretation
According to the manufacturer's package insert, the EUROIMMUN Anti-PLA2R indirect immunofluorescence assay was positive in 77.1% of patients with biopsy proven primary membranous nephropathy (pMN). This corresponds well with published literature that approximately 70% of patients with pMN will have anti-phospholipase A2 receptor antibodies.
Cautions
This test should not be used as a stand-alone test but an adjunct to other clinical information. A diagnosis of primary or secondary membranous nephropathy (MN) should not be made on a single test result. The clinical symptoms, results on physical examination, and laboratory tests (eg, serological tests), when appropriate, should always be taken into account when considering the diagnosis of primary versus secondary MN.
Absence of circulating anti-phospholipase A2 receptor autoantibodies does not rule out a diagnosis of primary MN.
Method Description
Diluted patient samples are incubated with combinations of substrates. If the reaction is positive, specific antibodies of classes IgA, IgG, and IgM attach to the antigens. In a second step, the attached antibodies are stained with fluorescein-labelled antihuman antibodies and made visible with a fluorescence microscope.(Package insert: Anti-Phospholipase A2 Receptor (PLA2R) IFA EUROPattern Kit, EUROIMMUN US;V 11/23/2021)
Day(s) Performed
Monday, Wednesday, Friday
Report Available
3 to 7 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
86255
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
PLA2I | PLA2R, Immunofluorescence, S | 82991-1 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
PLA2I | PLA2R, Immunofluorescence, S | 82991-1 |