Higher IL-38 Serum Levels Recorded in Patients with Vitiligo

Radwa El-Sayed Mahmoud Marie, MD

New data from Egypt confirmed that interleukin (IL)-38 serum levels were significantly higher in patients with vitiligo when compared to health controls.

Additionally, higher IL-38 serum level was associated with both vitiligo severity and signs of activity.

The study, led by Radwa El-Sayed Mahmoud Marie, MD, Department of Dermatology, Venereology and Andrology, Faculty of Medicine, Suez Canal University, was the first of its kind: No previous studies had investigated the expression of IL-38 in patients with vitiligo.

Marie and investigators noted that IL-38, a member of the IL-1 family of cytokines, has been linked to the suppression of T-helper (Th)1 and Th17 activation, which attack against melanocytes in the body and are directly related to vitiligo.

With their study, Marie and colleagues evaluated IL-38 serum level in patients with vitiligo and examined the association between IL-38 level and vitiligo severity and activity.

The Methods

The case-control study consisted of 42 patients in total, 21 of whom had vitiligo and were recruited from the Dermatology Outpatient Clinic, and 21 healthy controls.

All laboratory assays were conducted at the Medical Biochemistry Laboratory, with the study itself having been conducted from August 2020 to March 2021.

Demographic and other relevant clinical data were obtained for each patients, and dermatological examinations were performed to assess the location, extent, and pattern of a patients’ vitiligo.

Severity of the condition was evaluated via the Vitiligo Extent Score (VES) and Vitiligo Disease Activity (VIDA) Score was used to evaluate vitiligo activity, and were graded accordingly: +4: activity within the previous 6 weeks or less, +3: activity within the previous 6 weeks to 3 months, +2: activity within the previous 3–6 months, +1: activity within the previous 6–12 months, 0: stability for 1 year or longer, and −1: stability for one year or longer with occasional re-pigmentation.

The Findings

Regarding clinical features of patients with vitiligo, 11 (52.4%) patients presented with generalized vitiligo, 5 (23.8%) had acrofacial vitiligo, 4 (19%) patients had focal vitiligo, and 1 (4.8%) presented with segmental vitiligo.

Marie and investigators reported that patients with vitiligo had significantly higher serum level of IL-38 (mean 49.644 ± 20.359 pg/ml, range 22.517–95.314 pg/ml) than Hcs (mean 12.416 ± 2.824 pg/ml, range 7.347–18.873 pg/ml) (p < 0.001).

Additionally, those with the highest serum level of IL-38 tended to be patients with signs of activity (p = 0.048), especially those who had ill-defined border (p = 0.002) and Koebner's phenomenon (p = 0.034).

Further, Marie and colleagues found a strong, positive correlation between serum level of IL-38 and VES (p < 0.001), and significant negative correlations were recorded between serum level of IL-38 and the age of patients (p = 0.001) and the age of disease onset (p = 0.022).

Clinical features of vitiligo such as gender, clinical pattern, disease duration, and VIDA score did not influence IL-38 serum levels.

The investigative team cited several limitations to their study including a small sample size and a lack of assessment of IL-38 expression in vitiligo skin lesions versus perilesional skin and healthy controls skin, among others.

As such, further research was suggested.

“Our results provide preliminary data that IL-38 may play a role in the immune dysregulation implicated in vitiligo, and is related to vitiligo disease activity and severity,” the team wrote. “Nevertheless, more future research with a larger sample size is required to identify the expression of IL-38 in vitiligo lesions and its molecular roles in vitiligo.”

The study, “Interleukin 38 serum level is increased in patients with vitiligo, correlated with disease severity, and associated with signs of disease activity,” was published online in the Journal of Cosmetic Dermatology.