PT  - JOURNAL ARTICLE
AU  - Balada, E
AU  - Simeón-Aznar, C P
AU  - Ordi-Ros, J
AU  - Rosa-Leyva, M
AU  - Selva-O’Callaghan, A
AU  - Pardos-Gea, J
AU  - Fonollosa-Pla, V
AU  - Vilardell-Tarrés, M
TI  - Anti-PDGFR-α antibodies measured by non-bioactivity assays are not specific for systemic sclerosis
AID  - 10.1136/ard.2007.085480
DP  - 2008 Jul 01
TA  - Annals of the Rheumatic Diseases
PG  - 1027--1029
VI  - 67
IP  - 7
4099  - http://ard.bmj.com/content/67/7/1027.short
4100  - http://ard.bmj.com/content/67/7/1027.full
SO  - Ann Rheum Dis2008 Jul 01; 67
AB  - Objective: To evaluate the presence of anti-PDGFR-α antibodies by immunological methods in patients with systemic sclerosis (SSc).Methods: Fifty-eight women diagnosed with SSc and 36 healthy women controls were included. IgG anti-PDGFR-α were measured by ELISA and immunoblot. Associations with clinical and immunological findings were also studied.Results: Non-significant differences were detected between patients with SSc and controls: median value 0.287 (range 0–2.06) versus median value 0.226 (range 0–2.94), respectively (p = 0.583). No correlation between the presence of anti-PDGFR-α antibodies and clinical and serological features was found. Serum samples from patients with SSc and healthy people who had high titres of anti-PDGFR-α antibodies by ELISA recognised the same band corresponding to PDGFR-α by immunoblot.Conclusion: Although anti-PDGFR-α antibodies seem to be disease-specific when determined by bioactivity assays, these antibodies are also detected in normal subjects when immunological methods are used. Thus, anti-PDGFR-α antibodies may arise from natural autoantibodies. Possibly, SSc autoantibodies recognise a different epitope on the PDGFR-α molecule which triggers its stimulatory effect when analysed by functional assays. Alternatively, naturally occurring autoantibodies may even become pathogenic after affinity maturation and class switching in genetically susceptible subjects.