Interleukin-1 receptor antagonist in systemic lupus erythematosus and rheumatoid arthritis

Abstract EN

Objective: to evaluate the relation between plasma interleukin-1 receptor antagonist (IL-1ra) level and the clinical subsets of systemic lupus erythematous (SLE) & rheumatoid arthritis (RA).

Also, to correlate the IL-1ra level with the activity of either disease and to determine if it has a value as an indicator of certain systemic involvement.

Subjects : the study was performed on 60 subjects ; they were divided into 3 groups : Group I : included 25 patients suffering from SLE, who was divided according to SLEDAI into 2 subgroups, subgroup I (inactive) and subgroup II (active).

Group II : included 25 patients suffering from RA who were divided according to DAS of RA into 3 subgroups, subgroup I (mildly active), subgroup II (moderately active) and subgroup III (severely active).

Group III : included 10 normal volunteers, age and sex matched with the patients.

Methodology : Full history taking, complete clinical examination and assessment of disease activity in SLE and RA patients and laboratory investigations including : For SLE group (complete urine analysis, protein in urine / 24 hours, ANA, anti-ds DNA antibody, complement 3 & 4).

For RA group (rheumatoid factor titer).

For all subjects (plasma IL-1 receptor antagonist).

Plain-X-rays: both hands (P-A view) for RA group and chest X-ray (P-A view) for all subjects.

Results : there was a highly significant difference in plasma IL-1ra in all studied groups.

A significant elevation of plasma IL-1ra was found in active SLE and RA patients as compared to inactive patients with a highly significant positive correlation with parameters of disease activity in each group.

Plasma IL-1ra level was variable with the clinical manifestations of SLE patients, where its mean value was high in the presence of myositis, seizures, vasculitis, arthritis and skin manifestations, while low to moderate level was noticed with renal manifestations.

A significant elevation of IL-1ra level among RA patients with positive RF and SC nodules with a highly significant positive correlation between RF titer and IL-1ra level.

Also, a highly significant positive correlation was observed between all functional and radiological grades of RA patients and IL-1ra level.

Conclusion : measurement of IL-1ra in the plasma of SLE & RA patients is likely to have a clinical value and to play a role in the pathogenesis of both of them and have a favorable impact on the management of such patients.

Plasma IL-1ra could be taken as a new biologic marker of disease activity of both diseases and marked elevation could be useful also as a marker of CNS involvement, myositis and vacuities in SLE patients and a prognostic marker of joint destruction in RA patients.