1. CHRONIC TRANSPLANT GLOMERULOPATHY - clinical and histological characteristics
Agnieszka Perkowska-Ptasinska1, M. Ciszek, A.L. Urbanowicz, L. Paczek,
M. Glyda, A. Debska-Slizien, A. Rydzewski, K. Dziewanowski, M. Myslak
and M. Durlik
1Transplantation Institute, Warsaw Medical University, Poland

2. CHRONIC TRANSPLANT GLOMERULOPATHY
MORPHOLOGY:
double contours of glomerular capillaries,
no IF/EM deposits
CLINICALLY:
proteinuria, hypertension, declining graft function and graft loss
Habib 1993;
Regele J Am Soc Nephrol 2002;
Sijpkens Ki 2004;
Gloor AJT 2006;
Sis AJT 2007;
Gloor AJT 2007;
Cosio AJT 2008;
Clinically it is associated with……..
And, as it was shown repeatedly, it exerts a negative impact on graft survival

3. CHRONIC TRANSPLANT GLOMERULOPATHY
rare before 6 months after Tx,
the incidence rises from % at 1 year to 20% at 5 years
more common in patients with:
historical or ongoing acute rejection
DSA (especially against HLA II Ag )
- ABO incompatibility with a donor
- non-HLA reactive Ab (MICA, anti-endothelial cell Ab,
anti-angiotensin type 1 receptor Ab)
As for pathological processes TG has been proved to be associated with the presence of DSA
As for morphological characteristics the only lesions that have been implicated as commonly occurring together with TG are PTC-itis and C4d in PTCs
the morphological context of TG has not been to date described, possibly due to quite limited numbers of cases analyzed in individual studies
TG is well documented to be associated with the presence of antibodies against the renal allograft , most notably antibodies against human leukocyte
antigen class II antigens,
Dinavahii J AM Soc Nephrol 2011
WillicombeTransplantation 2012
Dragun Curr Opin Organ Transplant. 2012

4. CHRONIC TRANSPLANT GLOMERULOPATHY
Lesions that accompany TG:
PTCitis,
glomerulitis
C4d in PTCs ,
Regele J AM Soc Nephrol 2002;
Shimizu KI 2002;
Aita Clin Transplant 2005;
Gloor AJT 2007; Sis AJT 2007,
Perkowska Trans Proc 2009
Up till now TG has been mostly associated with microvascular lesions in a form of…….
Until now small groups studied
what about the morphology
of the interstitium, tubules, arteries, arterioles?

5. The retrospective study of:
159 patients with TG and 85 recipients without TG, but with other chronic changes in the graft biopsy (IF/TA and/or chronic vascular lesions)
median observational time: 118 months (range months)
median time from Tx to biopsy: 55 months (range months)
F:102, M:142
AIM:
to give a detailed morphological characteristics of TG
to search for potential impact of each of studied lesions on graft survival
Methods:
the analysis of clinical and histological (LM) data
including C4d deposition in PTCs and glomeruli (IHC on paraffin sections)
I present results of the retrospective study conducted on 159 pts after ABO-compatible Tx who developed TG, and 85 recipients without TG, but with IFTA and/or CNI toxicity. The analysis encompassed clinical and histological data including C4d deposition detected immunohistochemically on paraffin sections.

6. additional parameters (added to Banff criterias)
Methods
Light microscopical evaluation based on Banff classification
Compartment
additional parameters (added to Banff criterias)
glomeruli
linear C4d in glomerular capillaries,
thrombi,
mesangiolysis,
globally and segmentally sclerosed glomeruli (%)
arteries
arteriosclerosis without the multiplication of elastic lamina
arterioles
subendothelial sclerotization,
smooth muscle cells hyperplasia,
thrombi
interstitium
PTCs’ dilatation

7. light microscopical evaluation Banff criteria + additional parameters
TG vs non-TG cases
light microscopical evaluation
Banff criteria + additional parameters TG
Non-TG p
C4d in PTCs
42.9%
1,3%
<0.0001
C4d in PTCs and glomerular capillaries
6.5%
0.03
C4d only in glomerular capillaries NS
PTC-itis
40.9%
11.8%
PTCs’ dilatation
35.9%
10.6%
Acute interstitial inflammation („i”)
30.8%
Total interstitial inflammation („ti”)
81.8%
68.2%
The percantage of globally/segmentally sclerosed glomeruli
30.2 ± 21.7
19.6 ± 21.2
Mesangiolysis
39%
Increase in mesangial celullarity
8.2%
Increase in mesangial matrix volume
48.4%
27.1%
0.002
Glomerulitis
61%
7.1%
Tubulitis
31.5%
0.0002
Endarteritis
9.8%
0.003
Arteriosclerosis without the multiplication of elastic lamina
18.9%
3.6%
0.001
Arteriosclerosis with the multiplication of elastic lamina
28.7%
22.9%
Arteriolar sclerotization
47.2%
18.8%
Arteriolar SMCs hyperplasia/hypertrophy
39.6%
Arteriolar wall hyalinisation
86.8%
77.7%
C4d+ in PTCs was found in 43% of TG cases.
In 7% we found it in both PTC and glomerular capillaries.
There was no single case in which we would find C4d solely in glomeruli.
we wanted to establish the spectrum of parameters that we should concentrate on, and we defined them by comparing TG with non-TG biopsies.
There is a wide spectrum of lesions, mostly inflammatory, but also structural that were significantly more common in TG group. I would like to attract your attention with couple of those that do not belong to Banff criterias, such as PTC’ dilatation, AS without multiplication of elastic lamina, and two arteriolar lesions: subendothelial sclerotization and SMC-hyperplasia, that were more common in TG group, whereas the incidence of classical AS and AH was not different.

8. Correlation between TG and other morphological lesions
rs (p)
C4d in PTCs
0.37 (<0.0001)
increase in mesangial matrix
0.32 (<0.0001)
increase in mesangial cellularity
0.4 (<0.0001)
segmentally and globally sclerosed glomeruli (%)
0.31 (<0.0001)
arteriolosclerosis
0.33 (<0,0001)
PTC-itis
0.27 (<0.0001)
PTCs’ dilatation
0.26 (<0.0001)
linear C4d deposition in glomerular capillaries
0.09 (0.2)
arteriolar SMCs hyperplasia/hypertrophy
„ti” lesion
0.2 (0.002)
tubulitis
arteriosclerosis without the multiplication of elastic lamina
0.21 (0.002)
„t” lesion
0.15 (0.03)
glomerulitis
0.15 (0.02)

9. graft survival in TG vs non-TG group
months
probability
Non-TG group
TG group

10. Patients’ survival non-TG group without graft loss TG group
probability
months
probability
months
non-TG group
without graft loss
TG group
with graft loss

11. Weibull regression model
TG group - graft survival
PARAMETER
univariate analysis,
Weibull regression model HR
95% CI p
>1 Tx
1.5
0.02
recipient’s age at the time of Tx >30y
5.3
donor’s age at the time of Tx >30y
2.0
0.003
TG recognition before 44th month after Tx
6.4
<0.001
TG recognition between 44-89th month after Tx
2.6
PTCs’ dilatation
0.05
Acute interstitial inflammation („i”)
1.7
AS without the multiplication of elastica
0.04
Thrombi in glomerular capillaries
3.7
0.001
C4d in PTCs
0.9 NS
C4d in glomerular capillaries (linear deposits)
1.4
The univariate analysis of graft survival revealed that among clinical factors, the 2 or 3 tx was associated with worse prognosis, as well as the older recipient and donor age, and the recognition of TG before 44th month after TX.
The recognition of TG later on after engraftment was associated with weaker negative impact of TG on the graft survival.
Among histological factors……….were associated with higher risk of graft loss, whereas C4d + in PTCs and glomeruli did not affect the prognosis.

12. TG group - graft survival
PARAMETERS included in the BEST multivariate regression model
multivariate analysis,
Weibull regression model HR
95% CI p
C4d in PTCs
1.1
0.68
AS without multiplication of elastica
1.5
0.02
TG recognition before 44th month after Tx vs base level
5.3
<0.01
TG recognition between 44-89th month after Tx vs base level
1.9
At least moderate interstitial inflammation (Banff ti2+3)
1.2
0.47
Mild interstitial inflammation (Banff ti1)
0.7
0.06
Recipient’s age at the time of Tx >30y
1.7
Thrombi in glomerular capillaries
2.2
In multivariate analysis the best subset of variables (model with the lowest AIC) encompassed 8 variables. The factors that were found to be the strongest risk drivers for the graft loss were:………..
The recognition of TG before the 44 th month after TX has the strongest impact on graft survival

13. TG C4d (+) vs TG C4d (-) clinical variables TG C4d (-) TG C4d (+) p
recipient’s sex
F: 50%
M: 50%
F: 27.27%
M: 72.73%
0.005
recipient’s age
at the time of Tx
40.1 ± 12.0
34.0 ± 10.7
0.002
No significant difference in the:
level of proteinuria,
- number of current transplantation,
number of HLA mismatches,
percentage of highly (>50%) immunized recipients,
level of immunosupression,
time interval between Tx and recognition of TG.
donor’s age and sex,
Subsequently we went into the comparison of C4d+ vs C4d- TG groups.
We have found out that C4d+ occurs more commonly in younger and in male recipients
No differences in other analysed parameters including those that define patients immunologically

14. histological parameters pathologial recognitions
TG C4d (+) vs TG C4d (-)
histological parameters
TG C4d (+)
TG C4d (-) p
PTC’s dilatation
60.61%
17.05%
<0.0001
PTC-itis
26.14%
with neutrophils
10%
0.01
pathologial recognitions
TG C4d (+)
TG C4d (-) p
OR (95%CI)
acute T-cell mediated rejection (type I,II)
27.66%
10.77%
0.03
3.17 ( )
The morphological analysis revealed that C4d+ group was characterized by more common occurrence of……….
Among pathological recognitions C4d+ group was characterized by more common occurrence of acute T cell mediated rejection.

15. CONCLUSIONS: TG vs non-TG group differ
clinically
TG exerts a negative impact on both recipients’ and grafts’ survival
The earlier TG development is associated with worse prognosis as for the graft survival
morphologically
TG is associated with a spectrum of both acute and chronic inflammatory as well as structural changes in glomeruli, tubules, arteries and arterioles. Among these lesions AS without elastica multiplication and glomerular thrombi are independent risk factors for the graft loss
PTC-itis, the presence of neutrophils in PTCs and PTCs’ dilatation are more common in C4d(+) TG cases
the only tissue compartment which morphology distinguishes C4d+ and C4d- groups are peritubular capillaries. C4d+ is associated with more common presence of dilatation, inflammation, including neutrophilic one.

16. Chronic VASCULAR lesions associated with TG
CONCLUSIONS:
Chronic VASCULAR lesions associated with TG
ARTERIOLAR SUBENDOTHELIAL SCLEROTIZATION
AND
ARTERIOLAR WALL SMCs HYPERTROPHY/HYPERPLASIA
- very few publications,
documented as a feature of thrombotic microangiopathies in native kidneys
(antiphospholipid syndrome,LN,
malignant hypertension, scleroderma,HUS)
Caetano Hypertension 2001
Nochy J Am Soc Nephrol 1999
Ruggenenti Am J Kidn Dis 1996
the only tissue compartment which morphology distinguishes C4d+ and C4d- groups are peritubular capillaries. C4d+ is associated with more common presence of dilatation, inflammation, including neutrophilic one.

17. Chronic VASCULAR lesions associated with TG EXERTS NEGATIVE IMPACT
CONCLUSIONS:
Chronic VASCULAR lesions associated with TG
ARTERIOSCLEROSIS WITHOUT THE MULTIPLICATION OF ELASTIC LAMINA
(proliferative arteriopathy)
Characteristic for dynamic fibrotic tissue proliferation in the intima typical of inflammatory and thrombotic vasculopathies
in renal transplants: one study???
Wieczorek AJT 2006
the only tissue compartment which morphology distinguishes C4d+ and C4d- groups are peritubular capillaries. C4d+ is associated with more common presence of dilatation, inflammation, including neutrophilic one.
EXERTS NEGATIVE IMPACT
ON GRAFT SURVIVAL

18. most probable Ab-mediated and/or TMA related
CONCLUSIONS
TG is commonly associated with arterial and arteriolar lesions that share the same pathogenesis, evolve on the background of chronic endothelial injury,
most probable Ab-mediated and/or TMA related