WesternBlots -
ImmunoBlots
Table of detectable auto-antibodies
|
Type of Antibody |
Molecular Weight, (kD) |
Specificity of the antigens |
|
anti-Sa |
55 kD * * The 50 kD antigen is a degradation product of the 55 kD |
The specificity of anti-Sa antibodies for Rheumatoid Arthritis was 98.9%, the positive predictive value was 96.7%, while its negative predictive value was 69.8%. Anti-Sa antibodies occurred independently from rheumatoid factor (RF). Testing of anti-Sa plus HLA class II DRB alleles (DRB1*01 and DRB1*04 subtypes) was the best combination of immunologic markers for the diagnosis of destructive adult RA. |
|
anti- SS-A |
60 kD, 52 kD |
Demonstration of only 60kD SS-A antibodies suggest SLE, whereas 60kD plus 52kD SS-A antibodies are indicative of SLE or Sjögren's syndrome. |
|
anti-SS-B |
45 kD |
SS-B antibodies usually - with rare exceptions - appear in combination with SS-A 52kD antibodies. SS-B antibodies are present in 45% of sera from SLE patients and in 90% of those from patients with Sjögren's syndrome. |
|
not defined RA-associated antigen |
~43 kD |
In addition to the rheumatoid arthritis specific Sa-55 and Sa-50kD antigen bands a further not yet defined antigen band with a MW of ~43kD, only reacting with sera from patients with RA could be observed (Personal findings). Its relevance still has to be evaluated. |