ABSTRACT
Background: Systemic Lupus Erythematosus [SLE] remains a potentially disabling, life-threatening and overall challenging disease. The role of T cell derived cytokine production in SLE is poorly understood. It was hypothesized that interferon-gamma [IFN-gamma] and interleukin-10 [IL-10] are important cytokines in the pathogenesis of SLE. Understanding their possible role in the pathogenesis might lead to the development of new, more targeted drugs to manage this intractable disease
Objectives: To study IFN-gamma and IL-10 mRNA expression in peripheral blood mononuclear cells [PBMCs] in patients with SLE, correlating them with the disease activity score as measured by Systemic Lupus Activity Measures [SLAM] score; in an attempt to throw light on their possible role in the pathogenesis of the disease
Subjects: Forty selected patients with SLE [15 with active disease as group I, and 25 in remission as group II] and 15 healthy controls with matched ages and sex were studied
Methods: Using reverse transcriptase-polymerase chain reaction [RT-PCR], IFN-gamma and IL-10 mRNA expression in PBMCs was measured in both patients and controls
Results: This study showed a significant [p<0.05] decrease in haemoglobin and lymphocyte percents in patients than in controls and a significant [p<0.05] increase in expression of both IFN-gamma and IL-10 mRNA in PBMCs of patients than controls. The IFN-gamma expression was higher in group I of patients than those in group II, however, this difference did not attain statistical significance [p>0.05]. There was also no statistically significant [p>0.05] difference between both groups of patients as regards IL-10 expression. A significant positive correlation was detected between IFN-gamma expression and SLAM score [r=0.36, p=0.02], also between IL-10 expression and duration of illness [r=0.175, p=0.018], and between IFN-gamma expression and IL-10 expression [r=0.85, p<0.001] but both IFN-gamma and IL-10 expression were negatively [insignificant] correlated with cortisone intake [r=0.22, p=0.06 and r=0.12, p=0.5, respectively]
Conclusion: Results of this work support the hypothesis that IFN-gamma and IL-10 play a key role in the immunopathogenesis of SLE and suggests that IFN-gamma might be considered as an important independent marker of disease activity