Toll-Like Receptor 9 (TLR9) as a Serological Biomarker for Severity and Complications of Psoriasis in Iraqi Patients

Abstract

Background: Psoriasis is chronic skin disease characterized by persistent inflammation, the pathogenesis of it attributed to many genetic, environmental and immunological causes. Objective: the study aims to assess the serum levels of TLR9 in Iraqi patients with psoriasis and examine their relationship with disease severity and associated complications. Materials and Methods: A case–control study was carried out involving 110 participants. The patient group consisted of 60 individuals with psoriasis, consecutively recruited from the Dermatology Outpatient Clinic at Merjan Teaching Hospital. The control group included 50 age- and sex-matched apparently randomly selected healthy volunteers. Venous blood samples were obtained from all participants, and serum TLR9 concentrations were quantified using an ELISA kit supplied by Bioassay Technology Laboratory (China). Disease severity was evaluated through the Psoriasis Area and Severity Index (PASI). Results: The mean level of TLR9 was significantly related to treatment response. Also, the mean level of TLR9 was markedly elevated in psoriatic patients with metabolic syndrome. The mean levels were significantly higher in patients with mild severity compared to other groups, as illustrated in Figure 1, (P = 0.042). Similarly, there is a significant inverse correlation between the serum level of TLR9 and PASI (P=0.04). In contrast, there was no significant difference in mean TLR9 with complications. Conclusion: Serum TLR9 levels were higher in control subjects and were associated with metabolic syndrome and favorable treatment response in patients with psoriasis. An inverse association between serum TLR9 levels and disease severity was observed, suggesting a role in systemic immunological activity rather than disease severity.