Toll-Like Receptors 4 and 9 Expression in Systemic Lupus Erythematosus and Dermatomyositis: Relation to Clinical Status and Disease Activity

Abstract

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.

Epidemiology of Idiopathic Inflammatory Myopathies in Africa

“…The frequency of typical electromyography findings varied between 60.6% in the largest series of IIMs 51 and 100% in a retrospective cohort study from South Africa involving 25 subjects with JDM, 36 as well as in the study from Senegal including 21 subjects 26 . The frequency of heliotrope rash ranged from 21.7% in the aforementioned study from Kenya 48 to 100% in a retrospective cross-sectional study from Tunisia 18 involving 20 patients with CAM and a retrospective cross-sectional study from Egypt 34 involving 17 patients with DM. The frequency of Gottron papules ranged from 7% in the study from Nigeria involving 14 cases with DM/PM 30 to 100% in the latter study from Tunisia 34 …”

“…As depicted in Figure 1, 39 of 9918 identified records were included 13–51 . Studies were conducted in 19 countries between 1958 and 2019.…”

“…Dermatomyositis was reported in 17 studies 13,20,21,24–26,29–31,33,34,37,42,43,45,48,51 (Supplementary Tables S5, http://links.lww.com/RHU/A286). The frequency of DM varied from 21% in a retrospective cross-sectional study from Nigeria involving 14 patients with IIMs 30 to 93% in the aforementioned cohort from South Africa involving 15 patients with IIMs 13…”

“…The main extramuscular organ involvements were reported in 11 studies 16,18,20,25,26,32,34,36,41,48,51 (Supplementary Table S10, http://links.lww.com/RHU/A286). The frequency of interstitial lung disease (ILD, definition not specified in most relevant articles 20,25,26,32,36,41,48,51 ) ranged from 4.3% in the study from Kenya 48 to 100% in the ASS case series 41 .…”

“…26 The frequency of heliotrope rash ranged from 21.7% in the aforementioned study from Kenya 48 to 100% in a retrospective cross-sectional study from Tunisia 18 involving 20 patients with CAM 30 to 100% in the latter study from Tunisia. 34 The main extramuscular organ involvements were reported in 11 studies 16,18,20,25,26,32,34,36,41,48,51 (Supplementary Table S10, http://links.lww.com/RHU/A286). The frequency of interstitial lung disease (ILD, definition not specified in most relevant articles 20,25,26,32,36,41,48,51 ) ranged from 4.3% in the study from Kenya 48 to 100% in the ASS case series.…”