systemic lupus erythematosus(SLE) is an autoimmune disease characterized by B-cell
hyperactivity, production of autoantibodyand abnormal immunoregulation. At
present, both interleukin-13(IL-13) and nerve growth factor(NGF) have been proved
to play a role in stimulating the proliferation and differentiation of human B-cells and
inducing immunoglobulin(Ig) synthesis.Tumor necrosis factor-a(TNF-a) is both a
proinflammatory and immunomodulatory cytokine. It was suggested to affect NGF
expression. Therefore, the present study was designed to determine serum NFG, IL-13
and TNF-αin 31 patients with systemic lupus erythematosus (SLE) and to assess their
relationship with the disease activity as measured by SLE Disease Activity Index
(SLEDAI). The results showed that the levels of serum NGF (308±85 pg/ml), IL-13(92.69±9.87 pg/ml) and TNF-a (50.6±11.3 pg/ml) in active SLE patients were
significantly higher than those in inactive SLE patients (NGF, 244±76 pg/ml;IL-13,
54.22±9.31 pg/ml;TNF-a,29.4±9.8 pg/ml)(p<0.01. The inactive patients also had
significantly increased serum levels of NGF, IL-13 and TNF-a as compared with
normal controls( NGF,72.29±23.6 pg/ml;IL-13, 35.20±12.70 pg/ml; TNF-a,8.7±3.0
pg/ml)(p<0.001). Spearman correlation analysis revealed that the serum levels of
NGF,IL-13 and TNF-a were correlated with disease activity index of
SLE(SLEDAI),ESR and serum levels of C3 and C4( NGF, r=0.442 , - 0.41, - 0.38 ;
IL-13, r=0.813 , -0.504 , -0.605 ;TNF-a, r=0.69,-0.43,-0.52 respectively).The serum
levels of NGF, IL-13 and TNF-a had a positive correlation ( r=0.506, p<0.01).
Significant positive correlations were observed between NGF, TNF-a and SLEDAI.
Also, a significant positive correlation was present between TNF-a and NGF
suggesting that elevated TNF-a levels may lead to a continued increase of NGF
production. In conclusion, the present results suggest that NGF, IL-13 and TNF-α
may play a role in the pathogenesis of SLE and closely correlated with the disease
activity, therefore they could be used as sensitive markers for evaluating the disease
activity.