Study of serum interleukin-17 in psoriatic patients with cardiovascular comorbidities

Background There is still much mystery surrounding the aetiology of psoriasis, a chronic multisystem illness. Psoriasis is associated with cardiovascular comorbidity, including atherosclerosis, lipid metabolism disorders, and thromboembolic accidents. Some have proposed that interleukin 17 (IL-17) mediates an immunologic cascade that is crucial to the development of psoriasis. Objective To assess serum levels of IL-17 in psoriatic patients, and to evaluate its possible relation to cardiovascular comorbidity. Patients and methods A total of 40 patients with chronic plaque psoriasis (group I) and 20 healthy controls (group II) were included in this case-control study. Psoriatic patients were subdivided into group IA (patients having cardiovascular complaints) and group IB (patients with no cardiovascular complaints). Serum IL-17 determination by ELISA technique was done for patients and controls. Left common carotid ultrasonography was performed for all subjects to measure intimal medial thickness (IMT) and internal diameter for detection of early atherosclerosis. Results The levels of serum IL-17 were found to be significantly higher in groups IA and IB when compared with the control group and also in group IA compared with group IB. Serum IL-17 levels were inversely related to high-density lipoprotein cholesterol levels in both groups IA and IB, but positively related to psoriasis area and severity index score in group IA. Compared with controls, groups IA and IB had significantly higher mean IMT of the left common carotid artery compared with the control group, and group IA had significantly higher IMT than group IB. Conclusion IL-17 pathway could be a crucial link between cardiovascular comorbidity and psoriasis. Determination of carotid artery IMT using the ultrasound technique provides reliable and early information about atherosclerosis in the subclinical stage of the disease in psoriatic patients.