1. 11 m with nephrotic range proteinuria
Patient
11 m with nephrotic range proteinuria

2. History 11 M with nephrotic range proteinuria Microscopic hematuria
U P/C 7
Microscopic hematuria

6. Alpha-1 Chain of Type IV Collagen
CONTROL
Alpha-1 Chain of Type IV Collagen
Patient

7. Alpha-5 Chain of Type IV Collagen
CONTROL
Bowman’s Capsule
Positive
Alpha-5 Chain of Type IV Collagen
Patient
Occasional TBM
Positive

8. Alpha-3 Chain of Type IV Collagen
CONTROL
Alpha-3 Chain of Type IV Collagen
Patient

9. Immunofluorescence Routine IF Negative for Ig’s and Complement
Alport’s Panel – Controls all positive
Negative for Alpha 3 and Alpha 5 in glomeruli
Positive for Alpha 5 in Bowman’s Capsule and some TBMs

14. Electron Microscopy
Lamellation, thickening and thinning of GBMs

15. Diagnosis Findings c/w Alport’s Syndrome, Autosomal Recessive Type
Mild Interstitial Fibrosis

16. Skin Biopsy to Confirm
The family history did NOT conform to an autosomal recessive pattern
A skin biopsy can be very helpful in that alpha 5 is not altered in typical Autosomal Recessive Alport’s Syndrome

17. Alpha-1
Alpha-5

18. Alpha-1

19. Alpha-5

20. Alpha-3

21. Skin Bx IF Alpha-1 is Positive Alpha-5 is Negative
The Type IV Collagen of Skin is composed of Alpha 1,1,2 and Alpha 5,5,6
There is NO Alpha-3 (so the Alpha-3 is a negative control in this case)

22. Diagnosis
Likely X-Linked Alport’s Syndrome, though the data is somewhat conflicting
Lets review and come back to the final dx at the end.

23. Alport’s Syndrome Recurrent hematuria Nerve deafness
Usually presents in early 20’s
Classic renal biopsy features by EM
Thickened and Thinned GBM
Lamination and Rarefaction
Grains

24. Alport’s Syndrome Frequency ~ 1:5000
Accounts for 1-2% of ESRD in the US, Europe and India
Genetics were unclear until very recently
Strict inclusion criteria not used

25. Alport’s Syndrome Genetics X-Linked (80-85%)
Autosomal Recessive (10-15%)
Autosomal Dominant (very rare)
Spontaneous mutations (10-15%)

26. Alport’s Syndrome Pathogenesis Genetic abnormality of type IV collagen
Each family has its own mutation
Hundreds of genetic variants all developing Alport’s syndrome

27. Alport’s Syndrome Type IV collagen
Multimeric protein
Three alpha chain monomers coil in a triple helix to form a protomer
Each monomer is a very large protein with an even larger gene
6 alpha chains of type IV collagen are known to exist
But only three are known to be expressed in protomers

28. Not All Combinations Exist
Type IV collagen
Alpha 1, Alpha 1, Alpha 2
Alpha 3, Alpha 4, Alpha 5
Alpha 5, Alpha 5, Alpha 6
Two protomers combine to form a dimer
Known products
Alpha 1,1,2 with Alpha 1,1,2
Alpha 3,4,5 with Alpha 3,4,5
Alpha 1,1,2 with Alpha 5,5,6
All Basement Membranes
GBM, Eye, Cochlea
Epidermis, Bowmans
Capsule

29. Type IV Collagen Composed of Alpha Chains NOT Beta Pleated Sheets
Protomers are Triple Helices

30. These Combinations Form Basement Membrane Mats
These Mats Incorporate Many Other Important Molecules e.g. Laminin, Entactin, et al

31. Alport’s Panel in Kidney Biopsy
Stain for a-1, a-3 and a-5 Chains of Type IV Collagen
a-1 ALL Basement Membranes and Mesangial Matrix
a-3 GBM, BCBM and DTBM
a-5 GBM, BCBM, DTBM and Epidermal BM
a-5 is Key to differentiating the forms of Alport’s
BCBM = Bowman’s Capsule Basement Membrane
DTBM = Distal Tubule Basement Membrane

32. Alport’s Syndrome Type IV collagen Known products
Alpha 1,1,2 with Alpha 1,1,2
Alpha 3,4,5 with Alpha 3,4,5
Alpha 1,1,2 with Alpha 5,5,6
ALL BMs & Mesangial Matrix
GBM, BCBM, DTBM
Epidermis, BCBM, DTBM
BCBM = Bowman’s Capsule Basement Membrane
DTBM = Distal Tubule Basement Membrane
BM = Basement Membrane

33. Genetic Types of Alport’s
X-Linked (80-85%)
Autosomal Recessive (10-15%)
Autosomal Dominant (very rare)
Spontaneous mutations (10-15%)

34. X-Linked – Alport’s Panel
Abnormality in alpha-5 so skin and kidney analysis of collagen subunits can be tested
Absence of staining for alpha-5 in glomerular, capsular and distal tubular basement membranes in Males
Discontinuous staining for alpha-5 in glomerular, capsular and distal tubular basement membranes in Females
Alpha-3 is also missing in a similar fashion since there is no alpha-5 to work with
Abnormalities seen in only 2/3 of patients!

35. Autosomal Recessive – Alport’s Panel
Abnormality in alpha-3 or alpha-4
Absence of staining for alpha-5 in glomerular basement membranes, persistence in capsular and distal tubular basement membranes
Alpha-5 positive in epidermis because that collagen is made of Alpha 1,1,2 with Alpha 5,5,6 – no alpha-3 or -4
So Skin examination alone will be normal and not reveal the Alports phenotype
Abnormalities of kidney seen in ‘most’ patients!

36. Alport’s Syndrome: Is Diagnosis Only Skin-Deep?
Skin biopsy in suspected cases is an excellent first step if …
Quality laboratory with experience
Interpreting skin IF for Alport’s is NOT trivial
Kashtan CE, Kidney Int 55: , 1999

37. Alport’s Syndrome
Skin Bx to rule in Alports Stain with Anti-a 5 of Type IV Collagen
Absent – Alport’s Syndrome
Segmental – Alport’s carrier
Positive – Cannot absolutely R/O Because...
Skin stains for a 5 in Autosomal Recessive Alport’s

38. Final Diagnosis
The kidney findings support Autosomal Recessive (abnormalities of Alpha-3 and/or Alpha-4) in that there is absence of 5 in GBM but presence of 5 in BCBM and DTBM
Alpha 3,4,5 with Alpha 3,4,5
Alpha 1,1,2 with Alpha 5,5,6
GBM, BCBM, DTBM
Epidermis, BCBM, DTBM

39. Final Diagnosis
The skin findings support X-Linked Alport’s Syndrome (abnormalities of alpha-5) in that there is absence of Alpha-5 and presence of Alpha-1 in Epidermis
Alpha 3,4,5 with Alpha 3,4,5
Alpha 1,1,2 with Alpha 5,5,6
GBM, BCBM, DTBM
Epidermis, BCBM, DTBM

40. Final Diagnosis Changes c/w Alport’s
Dr. Bell Talked with Dr. Cliff Kashtan at the University of Minnesota
Never seen a case like this
Suggested Athena Diagnostics for genetic testing