Features of the immune status and comorbidities in children with alopecia areata

Abstract

Increased incidence of alopecia has been noted in children at the present time. Participation of autoimmune (immunopathological) mechanisms in pathogenesis of this disease necessitates additional study of immune status and characteristics of comorbid pathologies. The aim of our study was to specify the features of immune status and comorbidities in children with alopecia areata. The observation group consisted of children with various types of alopecia areata (n = 57), a comparison group included children without clinical manifestations of alopecia or a history of alopecia (n = 157). We performed a comparative evaluation of major lymphocyte subpopulations (CD3+, CD3+CD4+, CD3+CD8+, CD3+CD19+), interleukins (IL-4, IL-6), immunoglobulins (IgA, IgM, IgG), parameters of phagocytic activity (absolute phagocytosis, percentage of phagocytosis, phagocytic number and phagocytic index) and IgE to house dust and cat hair. Analysis of comorbidities was also performed. Statistical processing was carried out with Jamovi software. We have found that the focal clinical form of alopecia prevailed over the subtotal and total forms by 1.8 times (p = 0.033) in the observation group rather than in comparison group, with common variable immunodeficiency being more often (1.4-fold), chronic tonsillitis (3.9-fold), allergic rhinitis (3.9-fold) and autoimmune thyroiditis, which was absent in the comparison group. Among the children with alopecia, disturbances of the T-cell link were revealed, i.e., a higher median levels of the relative and absolute numbers of CD3+CD4+ cells (p = 0.001 to 0.003), larger proportions of elevated values for IgA (4.1-fold), IgM (7.3-fold), IgG (13.2-fold) with p-levels of 0.0001 to 0.0008; increased IL-4 (8.1-fold) and IL-6 (4.6-fold), with p = 0.002-0.004, along with medium and relatively strong correlations with alopecia. In children with alopecia, we have determined a 3.3-fold proportion of reduced values of absolute phagocytosis and 3.7-fold reduced percentage of phagocytosis (p = 0.0012 to 0.028), with an sufficient correlation (weak to moderate strength) with alopecia, as well as lower values of the median phagocytic index and phagocytic number in the observation group (p < 0.001) associated with a average-strength correlation. Hence, an imbalance of the immune system components was revealed in children with alopecia which manifested with signs of immune hyperfunction, characteristic, e.g., of autoimmune and allergic processes, accompanied by more frequent registration of autoimmune thyroiditis and allergic rhinitis. Moreover, distinct signs of immune deficiency, are found, characterized by a decrease in phagocytic activity and higher incidence of common variable immunodeficiency and chronic tonsillitis.