Evaluation of the level of serum Interleukins (IL-2, IL-4, IL-15 andIL-17) and its relationship with disease severity in patients with alopecia areata

Abstract

Background Alopecia areata (AA) is a hair disease that causes hair loss without scarring. The etiopathogenesis of AA has not been fully understood yet. Objective To determine serum interleukin levels (IL-2, IL-4, IL-15, and IL-17) in patients diagnosed with alopecia areata and to investigate the relationship of IL levels with the duration and severity of alopecia areata and the response to tofacitinib therapy. Methods Patients (≥16 years old) diagnosed with alopecia areata and healthy individuals as a control group was enrolled. Baseline serum interleukin levels of the patients and controls were measured. In the patient group receiving tofacitinib therapy, serum interleukin levels were measured again after 6 months. Disease severity for alopecia areata was assessed using the Severity of Alopecia Tool. Results Sixty-one AA patients and 30 healthy individuals were included; they were comparable regarding age and sex. The mean disease duration for AA was 7 ± 6 years and the baseline mean Severity of Alopecia Tool score was 71 ± 30 (range, 20–100). Baseline IL-2, IL-4 and IL-15 levels were significantly higher in the patient group than those in the control group (p < 0.001 for each). No significant correlation was found between the baseline interleukin levels and either disease duration or disease severity (baseline Severity of Alopecia Tool score). Among the patients receiving tofacitinib (n = 22), all interleukin levels significantly decreased after treatment. However, no significant relationship between the change in interleukin levels and the change in the Severity of Alopecia Tool scores was observed after tofacitinib treatment. Study limitations This is a monocentric study conducted in a single university hospital. Conclusion High interleukin levels in alopecia areata patients and the significant decrease with treatment support the idea that interleukins have a role in pathogenesis. Nevertheless, no relationship could be demonstrated between IL levels and disease duration or severity.

The Role of Serum Th1, Th2, and Th17 Cytokines in Patients with Alopecia Areata: Clinical Implications

“…An increased serum level of IL-4 was described in patients with alopecia areata in comparison with the control group in numerous of previously published studies [ 23 , 27 , 38 , 52 ]. In a study by Teraki et al [ 23 ], higher serum levels of IL-4 were only detected in patients with localized alopecia areata in comparison with healthy controls.…”

“…Numerous studies described an increased serum level of IL-2 in patients with alopecia areata in comparison with healthy controls [ 11 , 22 , 23 , 24 , 25 , 26 , 27 ]. Moreover, higher levels of IL-2 mRNA were detected in peripheral blood mononuclear cells in patients with alopecia areata compared to control subjects [ 24 ].…”

“…Askin et al [ 27 ] reported a decrease in the serum level of IL-2 in patients with alopecia areata after tofacitinib treatment. However, no significant relationship between the change in interleukin level and the change in the Severity of Alopecia Tool (SALT) scores was observed.…”

“…Both cytokines signal through two shared receptor subunits, the IL-2/15β chain (CD122) and the common γ chain (γC) [ 29 ]. In patients with alopecia areata, an increased serum level of IL-15 compared to healthy controls was described [ 27 , 30 , 31 , 32 ].…”

“…According to Askin et al [ 27 ], a decreased serum level of IL-4 was observed in patients with alopecia areata in comparison with baseline after tofacitinib therapy. Gong et al [ 34 ] reported an increased serum level of IL-4 in the non-responder group when compared to the responders and healthy controls at baseline.…”