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HelpTest Code LAB9785 PMND1 Primary Membranous Nephropathy Diagnostic Cascade, Serum
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.
Secondary ID
609778Useful For
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
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| EURO | Phospholipase A2 Receptor, ELISA, S | Yes, (Order PLA2M) | Yes |
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| PLA2I | PLA2R, Immunofluorescence, S | Yes | No |
| THSD7 | THSD7A Ab, S | Yes | No |
Testing Algorithm
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
EURO: Enzyme-Linked Immunosorbent Assay (ELISA)
PLA2I, THSD7: Indirect Immunofluorescence Assay (IFA)
Specimen Type
SerumSpecimen Minimum Volume
1 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 |
| Gross icterus | OK |
Reference Values
ANTI-PHOSPHOLIPASE A2 RECEPTOR (PLA2R) ENZYME-LINKED IMMUNOSORBENT ASSAY:
<14 RU/mL: Negative
14 to 19 RU/mL: Borderline
≥20 RU/mL: Positive
PLA2R IMMUNOFLUORESCENCE:
Negative
THROMBOSPONDIN TYPE-1 DOMAIN-CONTAINING 7A ANTIBODIES:
Negative
Interpretation
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.
Method Description
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)
Day(s) Performed
Monday, Wednesday, Friday
Report Available
3 to 7 daysSpecimen Retention Time
7 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
83520
86255 (x1 or x2, if applicable)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| PMND1 | Prim Membranous Nephropathy Diag, S | 73737-9 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| EURO | Phospholipase A2 Receptor, ELISA, S | 73737-9 |
Forms
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.