Pathomorphological changes in the tubulointerstitial compartment in primary glomerulopathies
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Transcript of Pathomorphological changes in the tubulointerstitial compartment in primary glomerulopathies
Pathomorphological changes in the tubulointerstitial compartment
in primary glomerulopathies
S. Kostadinova – Kunovska1, G. Petrushevska1, R. Jovanovic1, L. Grchevska2, M. Polenakovic3
1. Institute of Pathology, Faculty of Medicine, Skopje, Macedonia2. Clinic for Nephrology, Clinical Center, Skopje, Macedonia3. Macedonian Academy of Sciences and Arts, Skopje, Macedonia
The tubulointerstitial compartment of the kidney makes about 80% of the total kidney volume.
The tubular segments comprise the major part of the nephron and are structurally and functionally heterogenous.
The interstitium is the extravascular, intertubular space comprised of cells and extracellular matrix.
Cells Fibroblasts Macrophages Dendritic cells
Extracellular matrix Collagen fibers (I, III, VI) Proteoglycans Glycoproteins (fibronectin, laminin) Interstitial liquid
The relative interstitial volume varies in different compartments of the kidney. Cortex: 7 - 9% Medulla: 30 - 40%
Structural support to the nephrons and blood vessels
Exchange processes between the tubular and vascular elements
Regulation of the glomerular filtration through the tubuloglomerular feed-back
Production and regulation of the extracellular matrix
Production of local and systemic hormones, etc.
Functions of the interstitium
Group of diseases characterized by histological and functional changes of the tubules and interstitium, responsible for the progression of renal diseases of different ethiologies
Primary Secondary – associated with primary disease
of the other renal compartments
Tubulointerstitionephritis (TIN)
Acute Interstitial edema Leukocyte infiltration Focal tubular necrosis
Chronic Interstitial fibrosis Mononuclear inflammatory infiltrate Tubular atrophy
Morphology
Membranous nephropathy Membranoproliferative glomerulonephritis IgA nephropathy Focal segmental sclerosis Diffuse proliferative glomerulonephritis Lupus nephritis Diabetic nephropathy, …..
TIN associated with glomerulonephritis
Phase I: Glomerular destruction and spreading of the damage to the tubulointerstitium
Phase II: Tubular cells (mediators)
Phase III: Activation of fibroblasts - fibrosis
Schena FP. Molecular biology studies for the progression of renal damage in human glomerulonephritis. Mac Medical Review 1999;53:37-9.
Pathogenesis of TIN associated with glomerulonephritis:
Pathogenesis of TIN associated with glomerulonephritis: Glomerular destruction
Alpers CE. The Kidney. In: Kumar V, Abbas AK, Fausto N (Eds). Robbins and Cotran Pathologic Basis of Disease, 7th edition. Philadelphia: Elsevier Saunders; 2005:955-1021.
Rastaldi MP. Epithelial-mesenchymal transition and its implications for the development of renal tubulointersitial fibrosis. J Nephrol. 2006;19:407-12.
Pathogenesis of TIN associated with glomerulonephritis: Tubular destruction
Epithelial-mesenchymal transition Cells lose their epithelial phenotype and acquire new,
mesenchymal one Mediators from the inflammatory infiltrate: EGF, FGF-2,
TGF-b1.
Basic events (Liu, 2004): Epithelial cells lose their adhesive properties De novo expression of Vimentin and α-SMA Disruption of the tubular basement membrane Migration of cells to the interstitium - myofibroblasts that
synthetise collagen
Pathogenesis of TIN associated with glomerulonephritis: Tubular destruction
T lymphocytes CD4 CD8
B lymphocytes
Macrophages
Pathogenesis of TIN associated with glomerulonephritis: Interstitial inflammatory infiltrate
Activated resident fibroblasts
Myofibroblasts
Accumulation of matrix proteins Collagens I, III, V, VI, XV and fibronectin Modified collagen type IV and laminin
Pathogenesis of TIN associated with glomerulonephritis: Interstitial fibrosis
Destruction of the renal interstitium
Tubular atrophy Obliteration of peritubular capillaries Atubular glomeruli
Consequent reduction of the glomerular filtration rate
Pathogenesis of TIN associated with glomerulonephritis: Interstitial fibrosis
50 renal biopsies with previously diagnosed primary glomerulopathy
At least 10 glomeruli, cortical tubulointerstitium and arteriolar segments
Clinical data for evaluation of the renal function (serum creatinine and proteinuria)
Control group of 20 samples from kidneys without pathological changes in the tubulointerstitial compartment (nephrectomised), without significant difference in the patients` age.
MATERIAL
Standard histochemical stainings for evaluation of the kidney biopsies: HeEo PAS Trichrom Masson Silvermethenamine Jones
Immunohistochemical stainings (single and double):Cytokeratin AE1/AE3Cytokeratin 7E-cadherinCollagen IVCD43 CD20
CD68CD34Ki-67HLA-DRVimentin-SMA
METHODS
METHODS
Morphometric analysis:
Presence of the interstitial fibrosis on the staining with Trichrom-Masson, expressed as % of the scanned view field
Number of T-cells, B-cells and macrophages on 10 selected view fields on adequate immunohistochemical stainings
Determination of the proliferative index in the tubulointerstitial compartment on the Ki-67 staining, expressed as number of cells per 10 high power view fields.
Semi-thin sections: DURCUPAN 1 µm sections Light-microscopic analysis of the changes of the tubules,
tubular basal membrane and the interstitium
METHODS
Toluidine blue PASM
Average age: 41,8 (SD=14,4; min.=15; max.=80)
@eni, 30%
Ma`i, 70%
35
15
Female, 30%Female, 30%
Male, 70%Male, 70%
RESULTS Analysed group
Average age: 55,2 (SD=14,41; min.=27; max.=76)
RESULTS Control group
@eni, 35%
Ma`i, 65%
7
13
Female, 35%Female, 35%
Male, 65%Male, 65%
RESULTS Entities
IgAN; (22); 44%
EGN; (3); 6%
MGN; (4); 8%
MSGN; (5); 10%
FSGS; (7); 14%
MPGN; (9); 18%
RESULTS Tubules
Toluidine blue; x1000 PASM; x1000
RESULTS Tubules
Collagen IV; x400
E-cadherin; x400Cytokeratin 7; x400
RESULTS Tubules
Ki-67; x400
Mean ±SE ±SD
IgANMSGN
MPGNFSGS
MGNEGN
Kontrola
Dijagnoza
-10
0
10
20
30
40
50
Ki-6
7
Analysed group: 6.62 cells/10 HPFControl group: 0.08 cells/10 HPF
p<0.05
RESULTS Tubular epithelial cells
Vimentin; x400
RESULTS Tubular epithelial cells
CK7 / Vimentin; x400
SMA; x400
RESULTS Tubular epithelial cells
HLA-DR; x400
RESULTS Interstitial inflammatory infiltrate
Toluidine blue; x1000
PASM; x1000
RESULTS Interstitial inflammatory infiltrate
CD43; x400 Analysed group: 68.3 cells/HPFControl group: 6.15 cells/HPF
p<0.01
Mean ±SE ±SD
IgANMSGN
MPGNFSGS
MGNEGN
Kontrola
Dijagnoza
-20
0
20
40
60
80
100
120
140
160
180
200
220
240
CD
43
RESULTS Interstitial inflammatory infiltrate
T cells
CD20; x400
Mean ±SE ±SD
IgANMSGN
MPGNFSGS
MGNEGN
Kontrola
Dijagnoza
-20
0
20
40
60
80
100
120
CD
20
Analysed group: 24.98 cells/HPFControl group: 1.15 cells/HPF
p<0.01
RESULTS Interstitial inflammatory infiltrate
B cells
CD68; x400 Analysed group: 27.16 cells/HPFControl group: 1.95 cells/HPF
p<0.01
Mean ±SE ±SD
IgANMSGN
MPGNFSGS
MGNEGN
Kontrola
D ija gnoza
-10
0
10
20
30
40
50
60
70
80
CD
68
RESULTS Interstitial inflammatory infiltrate
Macrophages
Analysed group: 114.48 cells/HPFControl group: 9.2 cells/HPF
p<0.01
Mean ±SE ±SD
IgANMSGN
MPGNFSGS
MGNEGN
Kontrola
Dijagnoza
-50
0
50
100
150
200
250
300
350
400
Vku
pen
broj
na
infla
mat
orni
kle
tki
vo in
ters
tici
umotT cells
58.26%
B cells 18.62%
Macrophages 22.92%
RESULTS Interstitial inflammatory infiltrate
Total inflammatory infiltrate
RESULTS Fibroblasts
SMA; x400Vimentin; x400
Mean ±SE ±SD
IgANMSGN
MPGNFSGS
MGNEGN
Kontrola
Dijagnoza
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
Fibr
oza
(%
)
Analysed group: 18.75%Control group: 5.32%
p<0.01
> 9% in 49/50 cases (98%)
RESULTS Interstitial fibrosis
RESULTS Correlations
T cells / morphologic parameters of tubular damage (HLA-DRα, Vimentin, α SMA, Ki-67) R = 0.32 – 0.48 (p<0.01; p<0.05)
B cells / morphologic parameters of tubular damage (HLA-DRα, Vimentin, α SMA, Ki-67) R = 0.38 – 0.45 (p<0.01)
Macrophages / morphologic parameters of tubular damage (HLA-DRα, Vimentin, α SMA, Ki-67) R = 0.3 – 0.47 (p<0.01)
Total inflammatory infiltrate / morphologic parameters of tubular damage (HLA-DRα, Vimentin, α SMA, Ki-67) R = 0.35 – 0.45 (p<0.01; p<0.05)
RESULTS Correlations
Fibrosis / morphologic parameters of tubular damage (HLA-DRα, Vimentin, α SMA, Ki-67)
R = 0.38 – 0.59 (p<0.01) Fibrosis / interstitial inflammatory infiltrate (CD20,
CD43, CD68, Total) R = 0.33 – 0.45 (p<0.05)
Fibrosis / serum creatinine R = 0.54 (p<0.01)
Serum creatinine / morphologic parameters of tubular damage (HLA-DRα, Vimentin, α SMA, Ki-67) R = 0.36 – 0.45 (p<0.01; p<0,05)
Serum creatinine / interstitial inflammatory infiltrate (CD20, CD43, CD68, Total) R = 0.44 – 0.47 (p<0.01)
CONCLUSIONS
In 98% (49/50) of the analysed cases there is tubular atrophy and fibrosis in the interstitium (>9%).
In 90% of the analysed cases there is mononuclear inflammatory infiltrate in the interstitium, mainly with focal distribution, composed of:
T cells (average 58.26%), B cells (average 18.62%) Macrophages (average 22.92%)
CONCLUSIONS
The correlation analyses provide arguments that histological abnormalities in the interstitium are closely related to each other and have impact on the kidney function.
Serum creatinine concentrations correlate to the interstitial fibrosis, to the degree of the tubular damage, as well as to the interstitial inflammatory infiltrate, due to which it can be used as prognostic parameter.