The need of electron microscopy
in kidney biopsy diagnosis
Yrjö Collan, MD, Dr. Med.Sci., FRCPath
Department of Pathology, University of Turku,
Finland, and the International University Program,
Turku, Finland
Elements of the kidney biopsy study in a
histopathology laboratory
 Traditional light microscopy: thin section, a number of
stains including H&E, PAS, silver methenamine, Congo
red, Masson´s trichrome.
 Immunofluorescence (IF) or other immunomicroscopy
including staining for IgG, IgA, IgM, fibrinogen, C1q,
kappa and lambda chains
 Electron microscopy, glutaraldehyde fixation, osmium
tetroxide treatment, plastic embedding, ultrathin sections,
staining of sections, study in an electron microscope
Evaluation of a study element
 Kidney biopsy diagnosis is a complicated decision process
and includes the element of uncertainty
 To decrease the influence of uncertainty many methods are
used in the study of biopsies and the clinical data are
carefully associated with the elements of the biopsy study:
the whole picture matters.
 Evaluation of an individual element can be done by
excluding the element from the decision process, and
looking how much the exclusion influences the final
diagnosis or uncertainties associated with it
The categories of EM
contribution to diagnosis
 Generally authors have found suitable to divide
the potential contribution in 3 categories:
 1. EM is absolutely necessary for final diagnosis
 2. EM has supporting influence to final diagnosis,
clarifiyng remaining uncertanties
 3. EM appears redundant, i.e. with no influence on
final diagnosis or associated uncertainties
 We cannot decide about the category if EM has
not been done.
Revising the diagnosis by reembedding in plastic
 Collan Y, Klockars M, Heino M: Revision of
light-microscopic kidney biopsy diagnosis in
glomerular disease. Nephron 20: 24-31, 1978
 18 paraffin embedded biopsies of 1967, positive
LM evidence of glomerular disease in 9/18. After
re-embedding in Epon, positive EM evidence of
glomerular disease in 18/18 cases. Also 1 micron
thick plastic sections of the re-embedded biopsies
had higher fraction of positive cases than 4 micron
thick paraffin embedded biopsies alone.
Conclusion from 1978
Improved resolution improves the reliability
of diagnosis
Re-embedding in plastic may be helpful
Spargo (Human Pathol 6:405, 1975) also
gave positive evaluation of the role of EM,
Muehrke et al. (Arch Intern Med 124:170,
1969) had been more reserved
For thin BM nephropathy re-embedding
in plastic is not the best solution
 Nasr SH, Markowitz GS, Valeri AM, Yu Z, Chen
L, D´Agati VD (Columbia Univ, New York,
USA): Thin BM nephropathy (TBMN) cannot be
diagnosed reliably in deparaffinized, formalin
fixed tissue. Nephrol Dial Transplant 22:12281232, 2007
 Shrinkage during the process, reflected in a GBM
thickness decrease of about 30%
Criteria for diagnosis of thin BM
nephropathy
 Haas M: Arch Pathol Lab Med 130: 699706, 2006
Conclusion on re-embedding in
plastic
 To get the best material for EM studies you
cannot rely on re-embedding
 You have to try to get plastic embedded
material for EM already at the early phase
of the handling of the kidney biopsy
Pearson et al. 1994
 Pearson JM, McWilliam LJ, Coyne JD,
Curry A: Value of electron microscopy in
the diagnosis of renal disease. J Clin Pathol
47: 126-128, 1994 (GB)
 EM valuable in about 75%, essential in
about 25%, irrelevant in 25%
Haas 1997
 A reevaluation of routine electron
microscopy in the examination of native
renal biopsies. J Am Soc Nephrol 8: 70-76,
1997 (USA)
 EM valuable in about 50% of biopsies
 However, of all biopsies, material should be
embedded in plastic to solve uncertainties
Herrera´s group 1997-2002 Gu X, Herrera GA: The value of electron microscopy in the diagnosis
of IgA nephropathy. Ultrastruct Pathol 26:203-210, 2002 (USA)
 Herrera GA: The value of electron microscopy in the diagnosis and
clinical management of lupus nephritis. Ultrastruct Pathol 23: 63-77,
1999 (USA)
 Herrera GA, Isaac J, Turbat-Herrera EA: Role of electron microscopy
in transplant renal biopsies. Ultrastruct Pathol 21:481-498, 1997
(USA)
 In general EM is valuable, especially in transplant biopsies
Wang et al. 1998
 Wang S, Zhang Y, Zou W: The evaluation
of electron microscopy in the pathological
diagnosis of renal biopsies. Zhonghua Yi
Xue Za Zhi 78: 782-784, 1998 (China)
 777 biopsies, EM considered valuable in
32% (about 1/3 of the biopsies)
Collan et al. 2005
 Collan Y, Hirsimäki P, Aho H, Wuorela M,
Sundstrom J, Tertti R, Metsarinne K: Value of
electron microscopy in kidney biopsy diagnosis.
Ultrastruct Pathol29:461-468, 2005 (Finland)
85 biopsies 71 nontransplnts
Essential
15.3 %
18.3
Additional info 58.8 %
53.5
No extra value 25.9 %
28.2
- Results in line with those of Pearson et al. (1994)
Wagrowska-Danilowicz &
Danilowicz 2007
 Wagrowska-Danilowicz M, Danilowicz M:
Current position of EM in diagnosis of
glomerular disease. Pol J Pathol58:87-92,
2007
 EM essential
35
(31.0 %)
 EM important 15
(13.3%)
 EM not needed 63
(55.7%)
Conclusion: EM of value in 44.3%
Mubarak & Kazi 2009
 Mubarak M, Kazi JI: Role of immunofluorescence
and EM in the evaluation of renal biopsies in
nephrotic syndrome in a developing country.
Ultrastruct Pathol 33: 260-264, 2009 (Pakistan)
200 biopsies useful essential helpful
IF
100%
23.5% 71.5%
EM
95.5
43.0
51.5
Darouich et al. 2010
 Darouich S, Goucha RL, Jaafoura MH,
Moussa FB, Zekri S, Maiz HB: Value of
electron microscopy in the diagnosis of
glomerular diseases. Ultrastruct Pathol
34:49-61, 2010 (Tunisia)
 52 biopsies, 20 examined with EM, 18
primary disease, 2 transplants. EM essential
of helpful in 60%.
Elhefnawy 2011
 Elhefnawy NG: Contribution of electron microscopy
to the final diagnosis of renal biopsies in Egyptian
patients. Pathol Oncol Res 17: 121-125, 2011
 120 biopsies for primary diagnosis
Hereditary Other
EM essential
100%
23.5%
useful
41.7%
unhelpful
33.0%
Conclusions
 The importance of EM in kidney biopsy diagnosis has
increased rather than decreased. Many studies now
find that EM is valuable in about 2/3 of the cases.
Differences in evaluation may be associated with the
material studied, and local factors, including
treatment.
 For the best service to the patient guarantee the EM
option
 Training in EM should also be a part or at least an
option in the education of pathologists
Pathologists and electron
microscopy
 Furness PN, Boyd S: Electron microscopy and
immunohistochemistry in the assessment of renal
biopsy specimens: actual and optimal practice. J
Clin Pathol 49:233-237, 1996
 Only 4% never requested EM. On average on 74%
of biopsies. Many (40%) would like to do EM
more often. But the pressure at work and the
distance to the EM unit!
 Education and management should both be
involved
As Haas says it
 “Electron microscopy provides essential or
helpful information to a substantial fraction
of cases, and whether a biopsy will fall into
the latter fraction is not apparent from the
clinical history”
 Haas M: Electron microscopy in renal
biopsy interpretation - when and why we
still need it. US Nephrology1:19-22, 2007
Diseases often needing EM (we
are looking for signs of these)
 Alport and other hereditary nephropathies
Cryoglobulinemic glomerulopathies
Dense deposit disease (MPG type II)
Early diabetic changes
Fabry´s disease
Recurrence of focal segmental sclerosis
Immunotactoid nephropathy
Staging membranous nephropathy
Thin GBM nephropathy
D´Agati et al. 2005
 D´Agati VD, Jennette JC, Silva FG: Non
neoplastic kidney diseases. Atlas of
nontumor pathology. Am Registry of
Pathology 2005
 EM not questioned
 Stress the evaluation of location and texture
of dense deposits of various kinds
A case
 10-year old boy. Macrocytic anemia, and
proteinuria. EM of the kidney biopsy shows
a few dense deposits in the GBM. Weak
IgG deposition, but no complement
deposition in immunofluorescence.
 What condition? Not mentioned in many
kidney biopsy books.
Imerslund-Grasbeck syndrome 1
 Hereditary condition. Starts at birth.
 Symptoms like in vitamin B12 deficiency.
 Cause: the ileal enterocyte receptor for the B12
and intrinsic factor complex is abnormal and the
patients do not absorb vitamin B12.
 The abnormal receptor is also found in the kidney,
tubules and glomeruli.
Imerslund-Grasbeck syndrome 2
 Patients often have proteinuria, but not
progressive
 The protein abnormality in the glomeruli seems to
bind IgG, which is found as weak deposition in
immunofluorescence investigation, and also seen
in EM as dark deposits either in the GBM or in
subendothelial position.
 No complement deposition is present.
Imerslund-Grasbeck syndrome 3
 The genetic abnormality is found at
chromosome 14, in which one of 2 protein
genes, which are part of the receptor
complex, is abnormal (cubilin gene CUBN
or amnionless gene AMN).
Imerslund-Grasbeck syndrome 4
 References:
 Kidney biopsy findings: Collan Y, Lähdevirta J,
Jokinen EJ: Selective Vitamin B12 malabsorption
with proteinuria. Renal biopsy study. Nephron
23:297-303, 1979
 General: Grasbeck R: Imerslund-Grasbeck
syndrome (selective vitamin B12 malabsorption
with proteinuria). Orphanet J Rare Dis: 1:17, 2006