Background Joint involvement in SLE is very common, affecting 90% of patients at some stage in the course of their disease (1).Arthritis featuring prominent radiological erosion in SLE is less common; however, in a small subset of patients an erosive pattern similar to RA develops (2).
Anti- heterogenous nuclear ribonucleoprotein A2 (anti-hnRNP-A2) occur in about one-third of patients with RA but rarely in other arthritides such as OA, PsA or reactive arthritis. Interestingly, in SLE patients anti-hnRNP-A2 autoantibodies were found to be significantly associated with erosive arthritis (3).
Objectives To investigate joint involvement in SLE and its relationship with autoantibodies to the hnRNP Ab A1 and A2, rheumatoid factor (R.F), Antinuclear antibody (A.N.A) and Anti-double stranded DNA (Anti-DSDNA) and correlation with articular involvement by joint x-ray.
Methods Case series study comparing diagnosis of arthritis by hand and wrist x-ray with anti-hnRNP A1 and A2 in Fourty SLE patients aged 17–60 years old with disease duration 1–17 years complaining of arthralgia or arthritis. A controlled group of 21 clinically normal persons, age and sex matched and blood samples are drawn and centrifuged. RF and auto-antibodies to nuclear antigens anti-nuclear antibodies (ANA) and anti-double stranded DNA were determined in all the patients. All patients underwent X-rays of the hands and wrists.
Results Anti-hnRNP A1 showed highly significant difference between study and control. Anti-hnRNP A2 showed significant difference between study and control.
Conclusions This study showed a high frequency of erosive arthropathy and autoantibody to both hnRNP antigens might become useful marker for joint involvement in SLE patients and identify SLE patients prone to develop joint damage
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Disclosure of Interest None declared