Renal Pathology Consultation, Wet Tissue
Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.
The Renal Pathology Consultation is performed by a Mayo Clinic renal pathologist and entails the performance of appropriate procedures and stains based on the material received, patient information and specific findings on the case in order to determine a diagnosis. Optimal/standard diagnostic interpretation of a medical kidney biopsy requires integration of the light microscopy, immunofluorescence, and electron microscopy findings together with the clinical and laboratory data for the patient. We follow published standards by the Renal Pathology Society for the diagnostic evaluation and reporting of non-neoplastic renal disease.(1)
Wet/unprocessed tissue submitted for light microscopy routinely includes the preparation of stains, which include hematoxylin and eosin (H and E), periodic acid Schiff (PAS), Masson trichrome, and Jones methenamine silver stains.
Wet/unprocessed tissue submitted for immunofluorescence may include the following stains in order to render an accurate diagnosis. These stains include: IgA, IgG, IgM, C1q, C3, albumin, fibrinogen, kappa light chain, and lambda light chain stains with C4d added if the biopsy is an allograft.
The IgG subtypes (IgG1, IgG2, IgG3, IgG4) are typically only utilized if the biopsy shows features suspicious for a monoclonal/monotypic deposition process involving IgG.
Alport (collagen IV, alpha 2 and alpha 5) staining is performed in the setting of biopsy findings that are consistent with hereditary nephritis/Alport syndrome.
Paraffin-Based Immunofluorescence Stains:
The paraffin-based immunofluorescence stains listed above would only be utilized in the special circumstance when there is no tissue or inadequate tissue available for standard immunofluorescence or if there are findings that raise concern for so-called “masked” deposits.
Phospholipase A2 Receptor (PLA2R) staining is performed in the setting of membranous nephropathy/glomerulonephritis to aid in determining whether it is most likely primary/idiopathic or secondary.
Wet/unprocessed tissue submitted for electron microscopy will be processed for transmission electron microscopy. A formal interpretive report is issued, incorporating the findings from all tests performed for diagnostic purposes.
See Pathology Consultation Ordering Algorithm in Special Instructions.
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Container/Tube: Renal Biopsy Kit (T231)
Specimen Volume: Entire specimen
Collection Instructions: Collect specimens according to the instructions in Renal Biopsy Procedure for Handling Tissue for Light Microscopy (LM), Immunofluorescent Histology (IF), and Electron Microscopy (EM) in Special Instructions.
1. Advise shipping specimens in Styrofoam transportation coolers to avoid extreme hot or cold temperatures to ensure specimens are received at required specimen stability temperature.
2. Attach the green pathology address label included in the kit to the outside of the transport container
1. Renal Biopsy Patient Information Sheet in Special Instructions
2. If not ordering electronically, complete, print, and send a Pathology Test Request Form (T246) with the specimen
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.