Villagra N.T., Gordon P, Bodi I., King A, Buk S., Hortobagyi T., and Al

Villagra N.T., Gordon P, Bodi I., King A, Buk S.,
Hortobagyi T., and Al-Sarraj S.
Departments of 1Clinical Neuropathology and 2Reumathology,
King’s College Hospital London, UK.
3Department
of Neurology-Histopathology,
Marques de Valdecilla Hospital, Santander, Spain
CII REUNIÓN DE LAS ASOCIACIONES TERRITORIALES DEL NOROESTE DE LA
PENÍNSULA IBÉRICA SOCIEDAD ESPAÑOLA DE ANATOMÍA PATOLÓGICA
Oviedo, 24 de abril de 2010
INTRODUCTION
Idiopathic inflammatory myopathies
INTRODUCTION
Membrane attach complex
Activated
by
Antibody
COMPLEMENT FUNCTIONS
• To defend from antigen
• To establish a relationship between
innate and acquired immune response
Activated
by
defective
proteins
• Elimination of immune complexes and
tissue damage products
The main use for diagnosis is to
investigate the deposition of
complement in the small capillaries
in dermatomyositis but the criteria
is not well established
MATERIAL
Included patients
239 cases: Neuropathology Muscle Biopsies Database (2002-2008):
-The clinical notes were reviewed and the clinical and pathological diagnosis was
concordant in 144 patients with:
Disease
Number of cases
Dermatomyositis (DM)
28
Inclusion body myositis (IBM)
37
Polymyositis (PM)
10
Connective tissue disease with
myositis (CTD)
12
Control
Muscular dystrophy (MD)
31
Normal muscle
26
MATERIAL
Antibodies panel
Utrophin
Myosin
H.C.
(neonatal)
C5b-9
(MAC)
Spectrin
W6/32
DRP3/20C5
WB-MHCn
aE11
RBC2/3D5
Species
Mouse
Mouse
Mouse
Mouse
Mouse
Dilution
800
150
5
200
60
Trademark
Dako
NovaCastra
NovaCastra
Dako
NovaCastra
Antibody
HLAABC
Clone
PATHOLOGICAL FEATURES
Dermatomyositis
Perifascicular atrophy
Sarcolemmal and cytoplasmic HLA stain with perifascicular enhancement
H&E
HLA-ABC
PATHOLOGICAL FEATURES
Inclusion Body Myositis
H&E
H&E
P62
Rimmed vacuoles
and inclusions
HLA-ABC
Diffuse atrophy,
dystrophic features
and inflammation
Sarcolemmal and
cytoplasmic diffuse
HLA staining
PATHOLOGICAL FEATURES
Polymiositis
H&E
H&E
CD3
HLA-ABC
RATIO OF C5b-9 CAPILLARY
EXPRESSION
Inflammatory myopathies, muscular dystrophies and control cases
Cases with C5b-9
capillary deposition
(%)
100
89,5
86,5
80
58,3
50
60
40
12,9
11,5
MD
Normal
20
0
DM
IBM
PM
CTD
• PM and CTD show less proportion of cases with positive C5b-9 capillaries
• Of 31 cases with MD, there were 4 cases of C5b-9 positive
• Three cases within “normal limits” showed few capillaries with C5b-9
• DM and IBM show similar percentage of cases with C5b-9 capillary staining
CAPILLARY STAINING
Low specificity of C5-b9, DM and IBM
Dermatomyositis
Inclusion Body Myositis
• 25 of 28 cases show capillary staining
• 32 of 37 cases show capillary staining
• The perifascicular stained capillaries areas
are more frequent than diffuse areas
• Focal areas and diffuse C5b-9 capillary
staining are noted on the most of cases
Final diagnosis of IBM
+
-
+
25
TP
44
FP
PPV = 36%
-
3
FN
15
TN
NPV = 83%
Sens.
89%
Spec
25%
C5b-9 staining
C5b-9 staining
Final diagnosis of DM
+
-
+
32
TP
37
FP
PPV = 46%
-
5
FN
13
TN
NPV = 72%
Sens Spec
86% 26%
CAPILLARY STAINING
Low specificity of C5-b9, DM and Poymyositis
Dermatomiositis
Polymyositis
• 25 of 28 cases show capillary staining
• 5 of 10 cases show capillary staining
• The perifascicular stained capillaries areas
are more frequent than diffuse areas
• Scattered or groups of positive capillaries
with C5b-9
Final diagnosis of IBM
+
-
+
25
TP
44
FP
PPV = 36%
-
3
FN
15
TN
NPV = 83%
Sens.
89%
Spec
25%
C5b-9 staining
C5b-9 staining
Final diagnosis of DM
+
-
+
5
TP
64
FP
PPV = 0,007%
-
5
FN
13
TN
NPV = 72%
Sens Spec
50% 17%
The observation of the cases has revealed that C5b9 capillary deposition displays two patterns:
Type 1 pattern
Type 2 pattern
C5b-9 CAPILLARY STAIN
Two patterns
C5b-9
DM
Pattern 1
•Continuous staining in capillaries
•Staining the whole thickness of the wall
•Usually on a clean endomysial background
C5b-9
IBM
Pattern 2
•Granular staining in capillaries
•Irregular staining of the capillary wall
•Usually some staining in the endomysium
TWO C5b-9 CAPILLARY
STAINING PATTERNS
Dermatomyositis
Inclusion body myositis
Type 1:
Continuous and intense staining
C5b-9
DM
24
Type 2:
Granular staining
C5b-9
IBM
Negative
81
Pattern 2
59
Pattern 2 + Pattern 1
50
50
Pattern 1 + Pattern 2
Pattern 1
13
DM
IBM
PM CDT
11
MD Control
C5b-9 PATTERN CAPILLARY STAINING
DM: granular staining is related to sarcolemmal labelling
C5b-9
DM
% Sarcolemma staining
100
% Capillary staining
50
C5b-9
DM
0
Pattern1
C5b-9
DM
Negative
Pattern
1+2
Pattern
2+1
• 50% of DM cases with pure pattern 1 show occasional fibres with
sarcolemma staining
• 50% of DM cases with capillary negativity show also occasional fibres
with sarcolemma staining
• When granular pattern (pattern 2) is observed all of the cases show
intense sarcolemma staining
C5b-9 PATTERN OF CAPILLARY STAINING
DM: continuous capillary stain
is related to absent sarcolemmal stain
C5b-9 PATTERN OF CAPILLARY STAINING
DM: granular staining is related to sarcolemmal labelling
C5b-9
C5b-9 PATTERN
PATTERN OF
OF CAPILLARY
CAPILLARY STAINING
STAINING
IBM:
IBM: granular
granular staining
staining (type
(type 2)
2) is
is related
related to
to sarcolemmal
sarcolemmal labelling
labelling
C5b-9
C5b-9 PATTERN
PATTERN OF
OF CAPILLARY
CAPILLARY STAINING
STAINING
Schematic representation of the two capillary C5b-9 deposition patterns in the muscle fascicles in DM
31.04% of cases show
combined pattern 1 and 2
(continuous and granular stain)
with
sarcolemmal
C5b-9 deposition
55.17% of cases show
exclusive pattern 1
(continuous stain)
without
sarcolemmal
C5b-9 deposition
• Different DM types showing different MAC patterns
• The treatment modifies the inflammatory mechanisms, such as the Final Common Way (C5b-9)
• They are the representation of the stage of the disease progression
C5b-9
C5b-9 PATTERN
PATTERN OF
OF CAPILLARY
CAPILLARY STAINING
STAINING
Autoantibody complex
against the endothelial
cells capillary
YY
Patterns of muscle deposition and activation complement pathway
C1 complex
C2a and C4b
fragments
Classical
pathway
C3
convertase
C3
hydrolysis
Alternative
pathway
C3b and C3a
fragments
C3b cleaves C5 into
C5a and C5bC5
C5b, C6, C7, C8 and C9
MEMBRANE ATTACK
COMPLEX
Inflammation products
secondary to other
pathogenic process
CONCLUSIONS
El deposito de C5b-9 en los capilares no es especifico. Es comúnmente positivo en los
capilares de miopatias inflamatorias pero además es visto en el 12% de las distrofias
musculares y el 11% de músculos controles
El patrón 1 de deposito de C5b-9 o tinción capilar homogénea es especifica de
dermatomiositis, siendo probablemente un mecanismo relacionado con la presencia de
autoanticuerpos endoteliales
El patrón 2 o tinción granular de los capilares y el sarcolema no es especifico,
representando probablemente una activación del complemento secundaria a inflamación y
degeneración o necrosis
Los casos de dermatomiositis con una mezcla de patrones 1 y 2 probablemente representen
un estado mas avanzado de la enfermedad donde ambos concurren una activación primaria y
secundaria del complemento
Nosotros proponemos que patrón 1 de tinción C5b-9 (homogéneo y sólido) puede ser
incorporado como una herramienta que contribuya al diagnostico de Dermatomiositis