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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.  



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.


Secondary ID

607367

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

Highlights

Anti-phospholipase A2 receptor (PLA2R) antibodies are highly specific for the diagnosis of primary membranous nephropathy.

 

As many as 70% to 75% of patients with primary membranous nephropathy are positive for anti-PLA2R.

 

This test can be used to identify whether a specific autoantibody is present in a patient with biopsy proven membranous nephropathy, or in a patient without a renal biopsy but with a clinical picture consistent with membranous nephropathy.

Method Name

Indirect Immunofluorescence Assay (IFA)

Reporting Name

PLA2R, Immunofluorescence, S

Specimen Type

Serum

Specimen 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.

Clinical Reference

1. Beck L, Bonegio R, Lambeau G, et al: M-type phospholipase A2 receptor as target antigen in idiopathic membranous nephropathy. N Engl J Med. 2009;361:11-21

2. Schlumberger W, Hornig N, Lange S, et al: Differential diagnosis of membranous nephropathy with autoantibodies to phospholipase A2 receptor 1. Autoimmun Rev. 2014 Feb;13(2):108-113

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 days

Specimen Retention Time

7 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test 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

Forms

If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.