Background
Vitiligo is a common, acquired pigmentary disorder of unknown etiology, affecting
up to 0.1–2% of the population worldwide. It is characterized by white macules
and patches. Loss of melanocytes in vitiligo appears to occur through a
combination of several mechanisms that act in concert. Interleukin (IL)-33 is a
recently discovered cytokine and one of the newest members that belongs to the
IL-1 superfamily of inflammatory cytokines, and is mainly expressed by different
types of structural cells. IL-33 is considered an alarmin because of its release
after necrosis or tissue damage.
Objective
The aims of the present study were to evaluate serum levels of IL-33 in
nonsegmental vitiligo patients and to examine its relationship with disease
severity and vitiligo type.
Patients and methods
This was a case–control study that included 40 vitiligo patients (group A) and 40
apparently healthy individuals as controls (group B), who were matched for age and
sex, at the Dermatology and Andrology Clinic, Benha University Hospital. All
participants were subjected to the following: detailed history taking, assessment
of the rule of nine score and the Vitiligo Disease Activity score measuring the activity
of vitiligo, tests to determine the distribution and morphology of the lesions,
complete dermatological examination, and laboratory investigations including
assessment of IL-33 using commercial enzyme-linked immunosorbent assay kits.
Results
The majority of our sample included females. Serum IL-33 levels were significantly
higher in patients affected by vitiligo as compared with controls. There was no
statistically significant difference in serum levels of IL-33 among different types of
vitiligo. There was no significant correlation between serum IL-33 levels and severity
of vitiligo. A statistically significant negative correlation was found between serum
levels of IL-33 and duration of vitiligo, and a statistically significant difference was
found in serum levels of IL-33 between stable (negative) type and progressive vitiligo.
Conclusion
Serum IL-33 levels in patients with vitiligo were significantly increased compared
with controls. There was a positive correlation between serum IL-33 levels and
disease activity, but there was no correlation with the clinical type of vitiligo. This
explains a possible systemic role of IL-33 in the pathogenesis of vitiligo, and IL-33
serves as an alarmin in inducing melanocyte death in vitiligo skin. Inhibiting IL-33
activity might be a novel therapeutic strategy in the treatment of autoimmune
inflammatory diseases such as vitiligo. |
