Expression of Toll‑like receptors 3 and 9 in Egyptian systemic lupus erythematosus patients

Systemic lupus erythematosus (SLE) is a common complex disease characterized by chronic generalized inflammation which may involve several tissues and organs.

The aim of this work was to study the expression of Toll-like receptors (TLR) 3 and 9 in SLE patients, and to investigate their relationship to clinical features, disease activity, and damage.

The current study included 24 Egyptian female SLE patients and 15 matched controls. Disease activity was assessed using the SLE Disease Activity Index (SLEDAI) and damage using the Systemic Lupus International Collaborating Clinics (SLICC) index. Expression of TLR3 and TLR9 in B- (CD19-positive) and T-lymphocytes (CD3-positive) was studied using flow cytometry.

Patient age ranged between 17 and 42 years (mean 26.17 ± 5.78 years). There was a significant difference between patients and controls regarding TLR3/CD3, TLR3/CD19, TLR9/CD3, and TLR9/CD19 expression (p < 0.0001). There were significant correlations of TLR3/CD3, TLR3/CD19, and TLR9/CD19 with serum creatinine (r = 0.52, p = 0.009; r = 0.504, p = 0.012; and r = 0.58, p = 0.003; respectively) and negative correlations with ALT levels (r = -0.42, p = 0.04; r = -0.49, p = 0.016; and r = -0.472, p = 0.02; respectively).

The results of the study suggest that TLR3 and TLR9 play a role in the pathogenesis of SLE, and have an impact on organ involvement in this disease. More studies concerning the biology and function of TLRs are required in larger patient cohorts, and may lead to development of a new class of drugs.