Table 1

Results of the technical comparison of indirect immunofluorescence (IIF), immunoblot and ELISA for the detection of anti-polymyositis/scleroderma (anti-PM/Scl) antibodies
Sample number
 IIF
 Immunoblot
 ELISA


Titer
 Pattern
 PM/Scl-75
 PM/Scl-100
 Other
 PM/Scl-100
 PM1-α
1
 1:10000
 FG, N
 ++
 +++
15.3
 17.7
2
 1:1000
 FG, N
 +
 +
2.9
 7.6
3
 1:3200
 FG, N
 ++
 ++
14.4
 29.2

1:320
 AMA




4
 1:320
 FG, N
 -
 +
1.1
 4.7
5
 1:1000
 FG, N
 +
 +
2.2
 12.1
6
 1:3200
 FG, N
 -
 -
0.6
 2.3
7
 1:1000
 FG, N
 ++
 +++
5.2
 13.3
8
 1:1000
 FG, N
 +
 +
2.3
 12.7
9
 1:3200
 FG, N
 +
 +++
 P38
 15.5
 36.1
10
 -
-
 +
1.7
 4.0
11
 1:1000
 FG, N
 -
 ++
19.2
 2.4
12
 1:1000
 FG, N
 ++
 +
1.2
 3.2
13
 1:3200
 FG, N
 +++
 +++
 Ku86, Jo-1
 6.5
 10.6
14
 1:3200
 FG, N
 -
 ++
2.1
 5.9
15
 1:3200
 FG, N
 ++
 +++
11.4
 22.5
16
 1:1000
 FG, N
 -
 +
3.6
 8.5
17
 1:1000
 FG, N
 +
 ++
3.2
 15.0
18
 1:3200
 FG, N
 ++
 ++
6.1
 11.8
19
 n.d.
 n.d.
 -
 ++
7.1
 19.4
20
 1:320
 N
 -
 +
2.1
 5.6
21
 n.d.
 n.d.
 +++
 ++
4.1
 12.8
22
 1:10000
 FG
 -
 +
 P38
 0.7
 1.5

1:10000
 SPA




23
 1:1000
 N
 n.d.
 n.d.
0.5
 2.7
24
 n.d.
 n.d.
 ++
 +++
18.2
 34.7
25
 1:10000
 N
 n.d.
 n.d.
 P38
 0.5
 2.0

1:1000
 Rib




26
 1:1000
 N
 n.d.
 n.d.
1.9
 8.4
27
 n.d.
 n.d.
 +
 ++
5.9
 19.4
28
 n.d.
 n.d.
 ++
 +++
20.9
 37.3
29
 1:1000
 Hom
 n.d.
 n.d.
 Ku86, Cen, M2
 0.6
 0.8

1:100
 N*




30
 1:1000
 N
 -
 +
0.6
 1.4
31
 1:3200
 Hom, N
 -
 -
0.5
 2.9
32
 1:3200
 N
 -
 -
0.5
 1.3
33
 1:320
 FG, N
 +
 ++
7.2
 25.7
Number positive/tested
26/29
 17/29
 27/29
26/33
 32/33

-, negative; +, weak positive; ++, positive; +++, strong positive; n.d., not determined; FG, fine granular; Hom, homogenous; SPA, spindle apparatus; N, nucleoli; AMA, anti-mitochondrial antibodies; Cen, centromere; Rib, ribosomal. * Primate liver.

Mahler et al. Arthritis Research & Therapy 2005 7:R704   doi:10.1186/ar1729