Test Catalog

Test Id : PMND1

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Primary Membranous Nephropathy Diagnostic Cascade, Serum

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Overview

Test Catalog

Useful For
Suggests clinical disorders or settings where the test may be helpful

Distinguishing primary from secondary membranous nephropathy using an algorithmic approach

 

Monitoring patients with membranous nephropathy at very low antibody titers

 

Screening for anti-phospholipase A2 receptor antibodies

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.

 

A titer increase, decrease, or disappearance generally precedes a change in clinical status.

Profile Information
A profile is a group of laboratory tests that are ordered and performed together under a single Mayo Test ID. Profile information lists the test performed, inclusive of the test fee, when a profile is ordered and includes reporting names and individual availability.

Test Id Reporting Name Available Separately Always Performed
EURO Phospholipase A2 Receptor, ELISA, S Yes, (Order PLA2M) Yes

Reflex Tests
Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial tests.

Test Id Reporting Name Available Separately Always Performed
PLA2I PLA2R, Immunofluorescence, S Yes No
THSD7 THSD7A Ab, S Yes No

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

The phospholipase A2 receptor (PLA2R) enzyme-linked immunosorbent assay (ELISA) is initially performed.

 

If the PLA2R ELISA result is less than 20, then the PLA2R immunofluorescence testing will be performed at an additional charge.

 

If the PLA2R immunofluorescence result is negative, thrombospondin type-1 domain-containing 7A (THSD7A) antibody testing will be performed at an additional charge.

Method Name
A short description of the method used to perform the test

EURO: Enzyme-Linked Immunosorbent Assay (ELISA)

PLA2I, THSD7: Indirect Immunofluorescence Assay (IFA)

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Prim Membranous Nephropathy Diag, S

Aliases
Lists additional common names for a test, as an aid in searching

Anti-PLA2R

PLA2R

Anti-THSD7A

Thrombospondin

THSD7

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

The phospholipase A2 receptor (PLA2R) enzyme-linked immunosorbent assay (ELISA) is initially performed.

 

If the PLA2R ELISA result is less than 20, then the PLA2R immunofluorescence testing will be performed at an additional charge.

 

If the PLA2R immunofluorescence result is negative, thrombospondin type-1 domain-containing 7A (THSD7A) antibody testing will be performed at an additional charge.

Specimen Type
Describes the specimen type validated for testing

Serum

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

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.

Forms

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

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.

1 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Gross lipemia OK
Gross icterus OK

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
Frozen 14 days
Ambient 8 hours

Useful For
Suggests clinical disorders or settings where the test may be helpful

Distinguishing primary from secondary membranous nephropathy using an algorithmic approach

 

Monitoring patients with membranous nephropathy at very low antibody titers

 

Screening for anti-phospholipase A2 receptor antibodies

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

The phospholipase A2 receptor (PLA2R) enzyme-linked immunosorbent assay (ELISA) is initially performed.

 

If the PLA2R ELISA result is less than 20, then the PLA2R immunofluorescence testing will be performed at an additional charge.

 

If the PLA2R immunofluorescence result is negative, thrombospondin type-1 domain-containing 7A (THSD7A) antibody testing will be performed at an additional charge.

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

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 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 (ELISA) and indirect immunofluorescence assay PLA2R results; however, the ELISA assay alone may be preferred for monitoring patients with membranous nephropathy over time for trends in anti-PLA2R antibody levels.

 

In the remaining 30% of patients with MN who are PLA2R-negative, anti-thrombospondin type-1 domain-containing 7A (THSD7A) was shown to have an approximate 10% prevalence (ie, about 3% of all primary MN patients).(3) Mouse podocytes express THSD7A and introduction of anti-THSD7A autoantibodies induces MN in murine models. Mouse podocytes do not express PLA2R so exogenous administration of anti-PLA2R does not recapitulate MN in mice.(4) Additionally, THSD7A has been described as a potential tumor antigen and, thus, it has been suggested that THSD7A-positive patients merit a thorough cancer screening.(5)

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

ANTI-PHOSPHOLIPASE A2 RECEPTOR (PLA2R) ENZYME-LINKED IMMUNOSORBENT ASSAY:

<14 RU/mL: Negative

14 to 19 RU/mL: Borderline

> or =20 RU/mL: Positive

 

PLA2R IMMUNOFLUORESCENCE:

Negative

 

THROMBOSPONDIN TYPE-1 DOMAIN-CONTAINING 7A ANTIBODIES:

Negative

Interpretation
Provides information to assist in interpretation of the test results

Therapy outcome can be monitored by measuring the anti-phospholipase A2 receptor (PLA2R) antibody titer. A titer increase, decrease, or disappearance generally precedes a change in clinical status. Thus, the determination of the antibody titer has a high predictive value with respect to clinical remission, relapse, or risk assessment after kidney transplantation.

 

According to the manufacturer's package insert, the EUROIMMUN Anti-PLA2R indirect immunofluorescence assay (IFA) was positive in 77.1% of patients with biopsy proven primary membranous nephropathy (pMN).(6) This corresponds well with published literature that approximately 70% of patients with pMN will have anti-PLA2R antibodies.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

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
Recommendations for in-depth reading of a clinical nature

1. Beck Lh Jr, Bonegio RGB, Lambeau G, et al: M-type phospholipase A2 receptor as target antigen in idiopathic membranous nephropathy. N Engl J Med. 2009 Jul 2;361(1):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

3. Tomas NM, Beck LH Jr, Meyer-Schwesinger C, et al: Thrombospondin type-1 domain-containing 7A in idiopathic membranous nephropathy. N Engl J Med. 2014 Dec 11;371(24):2277-2287. doi: 10.1056/NEJMoa1409354

4. Tomas NM, Hoxha E, Reinicke AT, et al: Autoantibodies against thrombospondin type 1 domain-containing 7A induce membranous nephropathy. J Clin Invest. 2016 Jul 1;126(7):2519-2532. doi: 10.1172/JCI85265

5. Stahl PR, Hoxha E, Wiech T, Schroder C, Simon R, Stahl RAK: THSD7A expression in human cancer. Genes Chromosomes Cancer. 2017 Apr;56(4):314-327. doi: 10.1002/gcc.22440

6. Package insert: EUROIMMUN Anti-PLA2R IFA Kit, EUROIMMUN US; V 09/24/2018

Method Description
Describes how the test is performed and provides a method-specific reference

Enzyme-Linked Immunosorbent Assay:

The test kit provides microtiter strips, each with 8 break-off reagent wells. In the case of positive samples, specific IgG antibodies (also IgA and IgM) will bind to the antigens. To detect the bound antibodies, a second incubation is carried out using an enzyme-labelled antihuman IgG (enzyme conjugate) catalyzing a color reaction.(Package insert: Anti-PLA2R ELISA [IgG] Kit, EUROIMMUN US; V 07/08/2020)

 

Indirect Immunofluorescence Assay:

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 inserts: Anti-PLA2R IFA Kit, EUROIMMUN US; V 09/27/2018; Anti-THSD7A IIFT EUROPattern, EUROIMMUN US;V 06/11/2019)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday, Wednesday, Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

3 to 7 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

7 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their account representative. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

See Individual Test IDs

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

83520

86255 (x1 or x2, if applicable)

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
PMND1 Prim Membranous Nephropathy Diag, S 73737-9
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
EURO Phospholipase A2 Receptor, ELISA, S 73737-9

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports