Serum thrombomodulin in systemic lupus erythematosus and juvenile rheumatoid arthritis

الملخص EN

Objective: Thrombomodulin is a thrombin receptor on the vascular endothelial cell surface, which is most likely released upon endothelial cell damage.

Serum soluble thrombomodulin (sTM) was assessed and investigated as a parameter of disease activity in children and adolescents with systemic lupus erythematosus (SLE) and juvenile rheumatoid arthritis (JRA).

Subjects and methods: Patients included in this study were regularly attending the Allergy and Immunology Clinic, Children’s Hospital, Ain Shams University.

They were 38 (76%) females and 12 (24%) males, their ages ranged from 5 to 18 years with a mean age of 14.3 ? 4.84 years.

They were divided into two groups; SLE group that included 20 patients and JRA group that included 30 patients.

The control group included 30 healthy age and sex-matched individuals for comparison.

Disease activity in SLE patients was evaluated by systemic lupus erythematosus disease activity index (SLEDAI) score while in JRA patients disease activity was determined by number of joints with active arthritis, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP).

Laboratory investigations included: hemoglobin, white blood cell and platelet count, ESR, CRP, complete urine analysis, urinary proteins, serum creatinine serum complement component C3, antinuclear antibody (ANA) and anti-DNA antibody.

Serum levels of sTM were determined by enzyme-linked immunosorbent (ELISA) assay.

Results: Serum levels of sTM were significantly higher in SLE and JRA patients in comparison to control group; there was no significant difference between SLE and JRA patients.

In SLE patients, a highly significant correlation was found between sTM and SLEDAI score (r = 0.99, p< 0.001).

In JRA patients, a highly significant correlation was found between sTM and number of joints with active arthritis as well as ESR (r = 0.85, p< 0.001; r = 0.93, p<0.001 respectively).

Levels of sTM were significantly higher in CRP positive than CRP negative JRA patients.

Conclusion: Serum sTM is a useful serolgic marker of disease activity in SLE and JRA.

It may prove to be a potential indicator for early and more aggressive treatment.

Furthermore, sTM may prove to be an important marker for vasculitis in general.