Systemic Sclerosis IgG antibodies Blot - Black Country Pathology Services

Test Category: Immunology

Investigation Name:Systemic Sclerosis IgG antibodies Blot

Alias or Abbreviation:Scleroderma

Intro:

Indication: Progressive systemic sclerosis (diffuse and limited form) and overlap syndromes. Further information: Profile includes the following antigens: Scl-70, CENP A, CENP B, RP11 and RP155 (RNA Polymerase III subunits), Fibrillarin, NOR90, Th/To, PM-Scl100, PM-Scl75, Ku, PDGFR (platelet derived growth factor receptor), Ro-52. SSc specific autoantibodies can aid in early diagnosis and differentiation of the disease types and may be present in more than 95% of patients. Scl-70 (DNA topoisomerase I) is present in up to 42% of SSc patients. Strongly associated with diffuse SSc but may be seen in some patients with the limited form. Increased risk of pulmonary fibrosis and cardiac involvement. Patients with Raynaud’s disease and positive Scl-70 are at higher risk of developing SSc. CENP-A and CENP-B (Centromere protein –A and –B) are the most comment autoantibodies detected in SSc. Centromere antibodies may also be observed in other autoimmune conditions such as SLE, PBC and Sjögren’s syndrome. Patients with Raynaud’s disease and positive centromere antibodies are at higher risk of developing SSc. Centromere antibodies are usually indicative of limited SSc. They can be associated with both forms of the disease. Fibrillarin (U3-RNP) antibodies are detected in 4-10% of SSc patients and are associated with diffuse SSc. They are more frequently observed in African American populations than Caucasian or Asian cohorts. They are associated with severe pulmonary disease, pulmonary hypertension, small bowel involvement and a poor prognosis. NOR90 (Nucleolus organising region) is not considered to be sensitive for SSc. Th/To are not highly specific for SSc but are primarily associated with limited SSc and increased frequency of pulmonary fibrosis and scleroderma renal crisis. PM-Scl includes the major autoantigens PM-Scl75 and PM-Scl-100. Antibodies to PM-Scl75 and PM-Scl100 antigen are found in 50-70% of patients with the polymyositis/scleroderma overlap syndrome. Ku antibodies are seen in a variety of diseases including systemic lupus erythematosus, mixed connective tissue disease, scleroderma and the polymyositis/scleroderma overlap syndrome. PDGFR (Platelet derived growth factor receptor) antibodies have a potential pathogenic role in tissue fibrosis via activation of fibroblasts but are a rarely seen in SSc (<5% of cases). RPII and RP155 (RNA polymerase III subunits) are part of the RNA polymerase III complex. Antibodies to RNA polymerase III are highly specific for SSc, particularly the diffuse form with increased risk of renal crisis.

Requestable Seperately?Yes

Minimum Sample Volume:0.5mL

Test Code:SDOT

Sample Type:

Serum Gel Tube (Gold top)/ Plasma

Complex Reference Range:Positive/ Negative

Collection Conditions / Other Information:1st class post or Transport

Referred to Another Laboratory?No

Storage Requirements:Ambient temperature

NPEX / PDF Reporting Available:Yes

EQA Scheme:Yes

Lead Contact Details:rwh-tr.bcpsimmunologyclinicalqueries@nhs.net

Email Address For Chasing Results:rwh-tr.ImmunologyLab@nhs.net

Methodology:Immunoblot

UKAS Reference Number:9580 (recommended)

Site Sample Tested:Immunology, New Cross Hospital, Wolverhampton

Minimum Request Interval (MRI):180 days (6 months) over 16y only