A study of annexin-V labeled-lymphocytes apoptosis in pediatric-onset systemic lupus erythematosus in comparison to juvenile rheumatoid arthritis

Background: In systemic lupus erythematosus (SLE), which is the prototype of autoimmune diseases, the autoimmune process seems to be antigen driven. Apoptosis is responsible for eliminating cells from the immune system that are autoreactive, and defects in apoptosis may contribute to autoimmune diseases such as SLE and juvenile rheumatoid arthritis (JRA). Objective: This work is aimed to study the apoptotic peripheral blood lymphocytes in patients with pediatric- onset SLE, to trace its correlations, if any, with the disease activity and clinical presentation, and to compare the apoptotic process to that in JRA, as an example of another rheumatologic disorder. Methods: The study was conducted on 32 patients with pediatric- onset SLE; their ages ranged between 5 and 25 years (mean + SD = 15.5 + 4.4). In addition to various laboratory investigations needed for diagnosis, assessment of different system involvement as well as disease activity, the percentage of early circulating apoptotic lymphocytes was measured by flowcytometry using Annexin –V. The results were compared to that of 20 age and sex matched clinically healthy children and adolescents as well as 10 JRA patients. Results: The percentage of circulating early apoptotic lymphocytes was significantly higher in SLE patients (mean ± SD = 7.02 ± 7.29 %) and JRA patients (mean ± SD=5.91± 6.00 %) as compared to healthy controls (mean ± SD = 1.89 ± 2.21 %; p=0.0003 and 0.023, respectively). The levels of apoptotic lymphocytes seemed higher in SLE patients than in JRA patients but the difference was statistically insignificant (p=0.58). There was no correlation between the percentage of circulating apoptotic lymphocytes and the disease activity markers (SLEDAI and ESR), different system involvement and the dose or duration of corticosteroids therapy. Conclusion: The general increase of circulating apoptotic lymphocytes seen in SLE patients may not be specific to SLE and could be seen with other autoimmune diseases. It seems that disturbance in the apoptotic process contributes more to the phenomenon of autoantigenicity rather than the prediction of the disease clinical activity or specific organ involvement.Keywords: SLE, apoptosis, annexin V, autoimmune diseases, JRA, PediatricEgypt J Pediatr Allergy Immunol 2003; 1(2): 118-2