Medical & Transplant Kidney Biopsy Consultation Kit Instructions

Renal biopsy is a useful tool in the evaluation of patients with a wide variety of kidney diseases.

A comprehensive panel of histochemical stains, immunofluorescence studies, and electron microscopy are all important in the full evaluation of medical and transplant kidney biopsies.

Renal biopsies have the best value for the patient and the treating physician when pertinent clinical information is provided, adequate tissue is obtained and the tissue is properly shipped by the local pathology laboratory. Our Medical & Transplant Kidney Biopsy Consultation Kit provides the necessary materials to ensure specimen integrity during shipment to our laboratories.

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Overview

Medical & Transplant Kidney Biopsy Kit:

Overview

Renal biopsy is a useful tool in the evaluation of patients with a wide variety of kidney diseases. Patients who have received a kidney transplant are often biopsied to monitor for transplant rejection. Patients who have not received a transplant but who have conditions such as hypertension, diabetes, autoimmune diseases, infections, or other underlying illnesses can also develop kidney disease. Determining the cause of kidney disease often helps to guide clinical treatment. Renal biopsies for this purpose are sometimes referred to as “random” kidney biopsies or “medical” kidney biopsies in order to differentiate these biopsies from those that may be performed in the evaluation of a renal mass. A medical or transplant kidney biopsy is generally requested by either a nephrologist or a rheumatologist who is caring for the patient, and is typically performed by either an interventional radiologist or a nephrologist.

These renal biopsy specimens require highly-specialized processing techniques and evaluation by a renal pathologist. A comprehensive panel of histochemical stains as well as immunofluorescence studies, and often electron microscopy, are all important in the full evaluation of medical and transplant kidney biopsies. It is the job of the renal pathologist to combine the diagnostic information provided by these special processing techniques and interpret these findings in the clinical context in which the biopsy was performed.

Renal biopsies have the best value for the patient and the treating physician when pertinent clinical information is provided, adequate tissue is obtained and the tissue is properly shipped by the local pathology laboratory.

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Requisition

Medical & Transplant Kidney Biopsy Kit:

Requisition

Prior to sample collection, the treating physician should obtain and complete a Medical & Transplant Kidney Biopsy Requisition.

When filling out the referring physician contact information on the requisition, please be sure to provide the contact information for the physician who will be using the biopsy results to guide clinical decision-making.

Urgent results will be called to the physician whose contact information is listed. Complicated cases often require a conversation between the renal pathologist and the treating physician to maximize the diagnostic information that can be gained with the biopsy material.

Medical & Transplant Kidney Requisition

Specimen Requirements

Medical & Transplant Kidney Biopsy Kit:

Specimen Requirements

Prior to sample collection, the treating physician should obtain and complete a Medical & Transplant Kidney Biopsy Requisition.

Obtaining an adequate amount of renal cortex is critical for accurate diagnosis.

Separate portions of renal cortex are needed for light microscopy, immunofluorescence, and electron microscopy. Two cores of tissue, 1-2 cm in length, composed predominantly of renal cortex, will generally yield adequate glomeruli.

In typical cases:

At least 10 glomeruli are needed for light microscopy.

3-5 glomeruli are needed for immunofluorescence.

3-5 glomeruli are needed for electron microscopy.

If a thin needle (18 gauge) is used, a third core of cortex may be needed.

The physician performing the biopsy should be instructed to place the specimen on Telfa gauze that has been moistened with saline. If possible, confirmation that adequate glomeruli are sampled should be obtained during the procedure so that additional cores of tissue can be obtained if needed.

The specimen should then be delivered promptly to the local pathology laboratory where it can be properly divided and placed into the appropriate fixatives and transport solutions. The Medical & Transplant Kidney Biopsy Requisition should accompany the specimen.

Laboratory Handling

Medical & Transplant Kidney Biopsy Kit:

Laboratory Handling

The tissue cores should be handled delicately, preferably with a toothpick or needle, and divided (as described below) using a clean, sharp blade.

If using forceps, please take care not to pinch the cores.

10% Neutral Buffered Formalin

At least 10 glomeruli in 10% neutral buffered formalin are needed for light microscopy.

Michel’s Transport Media

3-5 glomeruli in Michel’s Transport Media (or Zeus Solution) are needed for immunofluorescence.

Glutaraldehyde

3-5 glomeruli in 2-4% glutaraldehyde are needed for electron microscopy (if applicable).

For transplant biopsies, electron microscopy is often not performed unless the patient has significant proteinuria.

Dividing the Cortex and Medulla

If you are using a microscope or hand lens to differentiate between cortex and medulla:

1. Place at least half of the cortical tissue in formalin for light microscopy (ideally more than 10 glomeruli).

2. The remaining cortex (ideally 6-10 glomeruli) can be evenly divided between Michels (or Zeus) fixative for immunofluorescence and glutaraldehyde for electron microscopy.

Alternate Specimen Dividing Technique

If you do not use a technique for distinguishing cortex and medulla, please use the following empiric technique to divide the specimen:

1. Cut a 1 mm portion of tissue from both ends of each tissue core and place it in glutaraldehyde.

2. Place 1/3 of what remains of each tissue core in Michel’s solution.

3. Place the remaining tissue (which should be at least half of the overall specimen) in formalin.

Dividing Limited/Suboptimal Specimens

Sometimes there may not be adequate tissue to divide into 3 parts and judgement must be exercised as to which diagnostic studies are most useful. In almost all cases, light microscopy is of the highest priority, and the best tissue should be placed in formalin. After light microscopy, immunofluorescence is typically most helpful; therefore, if possible, a small portion of cortex should be placed in Michel’s or Zeus solution for this purpose.

Our renal pathologists can sometimes perform electron microscopy on tissue after it has been used for light microscopy and immunofluorescence as a salvage technique; thus, electron microscopy should usually be given the lowest priority when dividing limited tissue. The main exception to this would be in the setting of pediatric nephrotic syndrome, where electron microscopy is typically more important than immunofluorescence.

For transplant biopsies, electron microscopy is typically not performed unless there is substantial proteinuria. If tissue is limited, medulla can be used for immunofluorescence to evaluate for antibody-mediated rejection. Therefore, when tissue is limited in the transplant setting, please prioritize light microscopy over all other modalities, and put a portion of medulla in Michel’s or Zeus solution for immunofluorescence.

Shipping Preparation

Medical & Transplant Kidney Biopsy Kit:

Shipping Preparation

1. After specimens have been divided into the appropriate containers, label all specimen parts with two of three patient identifiers:

  • Patient name
  • Date of birth
  • Social security number

2. Place all specimens into the appropriate openings in the grey foam insert.

3. Place the foam insert into the provided sealable biohazard bag.

4. Secure the bagged foam insert with the specimens into the green shipping box.

5. Place the completed requisition in the UPS Laboratory Pak.

Do not place the requisition in the biohazard bag.

6. Seal the specimens into the Laboratory Pak.

7. Affix the provided UPS label to the Laboratory Pak.

The specimen should be shipped Next Day Air to:

Cleveland Clinic Laboratories, L15
Pathology & Laboratory Medicine
2119 East 93rd Street
Cleveland, OH 44106

Contact Information

Medical & Transplant Kidney Biopsy Kit:

Contact Information

Surgical Pathology Desk

216.444.2836

Contact the Surgical Pathology Desk for technical tissue handling and shipping questions.

Renal Pathology Secretary

216.445.7605

Contact the Renal Pathology Secretary to arrange to speak with a renal pathologist regarding questions, including specific tests offered, testing indications, and interpretation.

Specimen Shipping Address:

Cleveland Clinic Laboratories
2119 E. 93rd Street, L15
Cleveland, OH 44106

Learn more about how to ship specimens to our laboratories.

For assistance 24 hours a day, 7 days a week,

Contact Client Services
1.216.444.5755 local
1.800.628.6816 toll-free
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