Transcript Serological Markers in Rheumatoid Arthritis

Serological Markers
in Rheumatoid Arthritis
Rheumatoid Arthritis
Systemic autoimmune disease
Characterized by chronic inflammation of the
joints resulting in tissue degradation and joint
destruction
1-2% of the world population
Diagnosis – primarily on clinical manifestation,
with only limited serological support
Clinical Manifestation of RA
1.
2.
3.
4.
5.
6.
7.
At
Morning stiffness
Arthritis of 3 or more joint areas
Arthritis of hand joints
Symmetric arthritis
Rheumatoid nodule
Serum rheumatoid factor
Radiographic change
least 4 of these criteria(1-4 at least for 6
wks)
Radiological Manifestations of RA
Periarticular soft tissue swelling
Osteoporosis
Marginal erosions progressing to
severe erosions of subchondral bone
Synovial cyst formation and lack of
bone repair
Hand, feet, knee, hips, cervical spine,
shoulder, elbow
Association of RA with HLA
HLA-DR4, sometimes DR1associated
with RA, but association is variable.
Functional similarity : Shared epitope
a.a. sequence in the HVR3 of the  chain
(QK/RRAA at positions 70-74 of the HLA
DRB1 chain)
Association of HLA with RA in Koreans
Hong, et al. J Rheumatol 1996
DR4
61% vs 29%
Shared epitope 57% vs 22%
DRB1*0405
DRB1*0401
RR=3.7
RR=4.8
RR=9.4
RR=8.8
Kim, et al. Tissue Antigens 1999
DRB1*0405
DQA1*03
DQB1*04
DQCAR113
DQCAR115
DQCAR 113/115
RR=6.6
RR=5.2
RR=3.5
RR=3.2
RR=3.6
RR=11.2
Serological Markers in RA
1. RA factor (IgM)
IgG/ IgA
2. Filaggrin associated Abs
1) antiperinuclear factor
2) antikeratin Ab
3) anticitrullinated filaggrin Ab
3. Anti-RA 33
4. Anti-Sa
5. pANCA
6. Other autoAb: HSP 60, type II collagen,
calreticulin, calpastain, MTOC(?), GiM(?)
Rheumatoid Factors (RF)
Ab to directed to the constant region of IgG
Usually IgM type, but IgG, IgA
Agglutination, nephelometry, ELISA based test
Detected in 70-80% of RA, in high % in other
autoimmune and infectious diseases, in up
to 15% of healthy individuals
Anti-perinuclear Ab(1)
Described by Nienhuis
and Mandema, in1964
Ab to a component of a
number of so-called
keratohyaline granules
surrounding the nucleus
in IIF using buccal
mucosa cells
Anti-perinuclear Ab(2)
Profilaggrin, precursor of filaggrin
colocalize with PF
Keratohyalin granule of epidermis contains
profilaggrin.
Sensitivity 49-91%, specificity 73-99%
APF positive buccal mucosa donor ~5%
Correlated with bone erosion in short term
Anti-keratin Ab(1)
Described by Young
in 1979
Determined by IIF on
cryosection of rat
esophagus –
stratum corneum
of rat eosophagus
epithelium
High correlation with
APF
Anti-keratin Ab(2)
Not cytokeratin
A neutral/acidic variant of human
epidermis filaggrin, a terminal
differentiation protein involeved in the
aggregation of cytokeratin filament
during cornification
Sensitivity 36-59%, Specificity 88-99%
Anti-filaggrin Ab
Filaggrin, cytokeratin filament aggregating
protein – the target of the so called
antikeratin antibodies (Simon et al., 1993,
J Clin Invest)
APF, AKA, anti-filaggrin extracted from
human epidermis have similar diagnostic
value… partially overlap, not totally
identical (Vincent et al., 1999, Ann Rhem
Dis)
Distribution fo RA and control serum samples with
regard to AKA, AFA and APF positivity
Vincent, et al. Ann Rheum Dis 1999
APF
N
AKA
N
P
AFA
N
P
P
P
P
P
P
P
P
P
P
P
RA
71
11
7
19
3
11
38
119
279
%
25.4
3.9
2.5
6.8
1.1
3.9
13.6
42.7
Control %
186
87.3
4
1.9
9
4.2
8
3.8
0
0
1
0.5
3
1.4
2
0.9
213
AFA immunoblot on filaggrin enriched epidermis extract
Comparison of Serological Markers in RA
RF
Filaggrin associated Ab
APF
AKA(AFA)
AFA
Sensitivity
(%)
70-80
40-80
35-55
Similar to
APF/AKA
Specificity
(%)
80-90
>90
>90
Similar to
APF/AKA
Good
Bad
Good ass /w
prognosis
Seronegative RF,
Appear late,
Titer fluctuation
Specific, Appear early, Less
change of titer
Less correl/w
prognosis
Lee available
substrate,
IF method
IF
method,
Less
sensitive
than APF
Stable Ag,
ELISA or IB
methods
Less
sensitive
than APF
Anti-Citrullinated Filaggrin Ab
RA associated Ab to filaggrin label the
fibrous matrix of cornified cells but not the
profillagrin containing keratohyalin granules
in human epidermis (Simon et al., 1995,
Clin Exp Immunol)
RA specific autoAb recognize citrulline,
posttranslational modified arginine residue
(Simon et al., 1998, J Clin Invest)
Profilaggrin: an acidic phosphorylated protein,
Epidermis
Consisting of 10 –12 tandemly repeated filaggrin
units separated by linker peptides
Dephophorylated
Proteolytically cleaved
Filaggrin: basic/neutral
intermediate filament associated protein
Citrullination by
peptidyl arginine deaminase
Cornification
Arginine
Citrulline
Citrullinated Filaggrin
Simon et al., 1998, J Clin Invest
Simon et al., 1998, J Clin Invest
Anti-citrullinated Filaggrin Antibody on ELISA(MBL)
87 sera tested on Hallym University Medical Center
RA
RF+ RA
Prev RF+/Present RF- RA
RF- RA
Total
N number
34
9
10
53
Positive
21
7
6
34
%
61.76
77.78
60.00
64.15
N number
12
22
34
Positive
1
1
2
%
8.33
4.55
5.88
Control group
RF+ non-RA
RF- healthy donor
Total
Sensitivity 64%, Specificity 94%, Efficiency 76%
Specific presence of intracellular citrullinated
proteins in rheumatoid arthritis synovium:
Relevance to antifilaggrin autoantibodies
Baeten et al., Arthritis Rheum 2001
Objectives: investigate the presence of citrullinated
proteins in synovial membrane of RA Pt
Methods: stain synovial tissue section of 88 RA pts and 52
other control pt with anti citrulline polyAbs(ACA) and
affinity purified antifilaggrin autoantibody(AFA)
Results: intracellularly staining of the lining and sublining
layers of RA synovial tissue with ACA and AFA, which
were colocalized
Prognostic factors in early RA
Important clinical outcomes
joint damage and functional disability
Prognostic factors
Joint involvement, RF positivity, ESR & CRP
IgA RF, RF + AKA or AFA : more active
Genetic predictors over RF : inconclusive
Guideline for aggressive treatment
Juvenile RA
Chronic inflammatory disease of unknown
etiology and pathogenesis
1. Polyarticular onset JRA (=>5 joints) 30%
1) younger children RF(LA) negative
2) older girl RF(LA) positive
2. Pauciarticular onset JRA (1-4 joints) 50%
1) early onset, young girl /w iridocyclitis, positive ANA
2) late onset, boy /w HLA B27, ankylosing spondylitis
3. Systemic onset JRA ( fever, arthritis, skin
rash, etc) 20%
Serological Markers for Juvenile RA(1)
1. RF
RF_LA 7-10% JRA, late onset polyarticular
ELISA IgM RF 22-35%
IgG RF 4-6%
IgA RF 30-60%
Hidden IgM RF
not detected by conventional methods
using IgM containing fraction from sephadex
chromatography
65(systemic onset) – 85% (polyarticular)
Serological Markers for Juvenile RA(2)
2. ANA
50-70% positive in JRA
young girl with pauciarticular onset, iridocyclitis
95-100% positive
 ANA positivity well known risk factor for
development of ant. uveitis
Speckled and homogeneous
No association with Sm, RNP, Ro, La, Scl70
Ab to Histone 40-70% of JRA
Serological Markers for Juvenile RA(3)
3. Other antibodies
anticardiolipin antibody 7-42%
anticollagen antibody 12-42%
antiperinuclear factor non – 40%