Sign in →

Test Code ALPRT Alport (Collagen IV Alpha 5 and Alpha 2) Immunofluorescent Stain, Renal


Shipping 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.



Necessary Information


A pathology/diagnostic report is required.



Specimen Required


Supplies: Renal Biopsy Kit (T231)

Source: Kidney or Skin

Container/Tube: Transport medium (Michel's or Zeus media) (T231), Frozen tissue.

Specimen Volume: Entire specimen

Collection Instructions:

1. For kidney cases, collect specimens according to the instructions in Renal Biopsy-Procedures of Handling Tissue for Light Microscopy, Immunohistology, and Electron Microscopy in Special Instructions.

2. If standard immunoglobulin and complement immunofluorescence has already been performed, submit the residual frozen tissue (must contain glomeruli) on dry ice.

3. For skin cases, submit punch biopsy in Zeus/Michel's.

Acceptable: 2 frozen tissue unstained positively charged glass slides (25- x 75- x 1-mm) per test ordered; sections 4-microns thick.


Useful For

Assisting in the diagnosis of hereditary nephritis (Alport syndrome)

Method Name

Direct Immunofluorescence on Fresh/Frozen Tissue

Reporting Name

ALPORT Immunofluorescence

Specimen Type

Special

Specimen Stability Information

Specimen Type Temperature Time
Special Ambient (preferred)
  Frozen 
  Refrigerated 

Reject Due To

Hemolysis

NA

Lipemia

NA

Icteric

NA

Other

NA

Reference Values

Reporting of immunofluorescent (IF) double staining for alpha 2 and alpha 5 chains of type IV collagen on kidney biopsies:

1) Normal pattern of staining (ie, preserved linear alpha 5 staining of glomerular basement membranes, Bowman capsule, and distal tubular basement membranes). This pattern of staining is seen in normal individuals and patients with thin glomerular basement membrane disease but does not exclude the diagnosis of hereditary nephritis/Alport syndrome.

2) Consistent with X-linked hereditary nephritis (Alport syndrome). There is global or segmental loss of alpha 5 staining of glomerular basement membranes, Bowman capsule, and distal tubular basement membranes. This pattern of loss of staining is usually due to mutations in the COL4A5 gene on the X chromosome.

3) Consistent with autosomal hereditary nephritis (Alport syndrome). There is global or segmental loss of alpha 5 staining of glomerular basement membranes but preserved alpha 5 staining of Bowman capsule and distal tubular basement membranes. This pattern of loss of staining is usually due to mutations in the COL4A3 or COL4A4 genes on chromosome 2.

4) No interpretation can be reported if the specimen contains no intact glomeruli.

 

Reporting of IF double staining for alpha 2 and alpha 5 chains of type IV collagen on skin biopsies:

1) Normal pattern of staining (ie, preserved linear alpha 5 staining of epidermal basement membranes). This pattern of staining is seen in normal individuals and patients with thin glomerular basement membrane disease but does not exclude the diagnosis of hereditary nephritis/Alport syndrome.

2) Consistent with X-linked hereditary nephritis (Alport syndrome): There is global or segmental loss of alpha 5 staining of epidermal basement membranes. This pattern of loss of staining is usually due to mutations in the COL4A5 gene on the X chromosome.

3) No interpretation can be reported if the biopsy contains no epidermis.

 

Notes:

1) Approximately one-third of patients with established hereditary nephritis based on typical ultrastructural findings and family history show loss of glomerular basement membrane or epidermal basement membrane staining for the alpha 5 chain of type IV collagen. Therefore, a normal staining pattern does not exclude the diagnosis of hereditary nephritis.

2) In patients with hereditary nephritis, preserved alpha 5 staining indicates small mutations (eg, missense, splice site) and is generally associated with a better renal outcome, while loss of alpha 5 staining indicates larger mutations (eg, deletion, nonsense, frame-shift) and a worse renal outcome.

3) Because alpha 3 and alpha 4 chains of type IV collagen are not expressed in the epidermal basement membranes, patients with autosomal hereditary nephritis have preserved staining for alpha 5 on epidermal basement membranes and, therefore, skin biopsy cannot exclude autosomal hereditary nephritis.

Day(s) and Time(s) Performed

Monday through Friday

Analytic Time

Turnaround time is 1 working day (from receipt)

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

88346-primary IF

 

LOINC Code Information

Test ID Test Order Name Order LOINC Value
ALPRT ALPORT Immunofluorescence In Process

 

Result ID Test Result Name Result LOINC Value
71285 Interpretation In Process
71268 Participated in the Interpretation In Process
71269 Report electronically signed by In Process
71270 Addendum In Process
71271 Gross Description In Process
71272 Material Received 81178-6
71619 Disclaimer 62364-5
71848 Case Number 62364-5