Systemic Lupus Erythematosus (SLE) is an autoimmune disorder
affecting almost all organs and tissues. Dermatomyositis (DM) is a
chronic muscle disorder that leads to muscle destruction. Although
DM mechanisms remain unclear, there is an evidence of autoimmune
origin. Toll-like receptors (TLRs) are the key initiators of innate and
adaptive immune response due to high production of proinflammatory
mediators and activation of antigen presentation. We used qPCR to
investigate the expression of TLR4 and TLR9 in peripheral blood
mononuclear cells (PBMCs) from SLE and DM patients, as well as
muscle tissue biopsies from the DM patients, to explore their role and
study their correlations with clinical manifestations and disease
activity. Our findings showed a significant increase in TLR4 and TLR9
expression levels in PBMCs from SLE patients and muscle biopsies
from DM patients. Such results emphasize the role of TLR signaling
and innate immune system in the pathogenesis of both diseases.