P#13   On the problem of pathogenetic heterogeneity of alopecia areata

A. Koubanova and A Gadjlgoroeva. Moscow, Russia

We searched for differences in the levels of Th-specific cytokines in peripheral blood of patients with mild and severe forms of alopecia areata (AA). Serum levels of Th-specific cytokines IL-2, IL-4 and TNF-a were determined in 24 patients with mild (n=8) and severe (n=16) forms of AA. A control group consisted of gender and age matched healthy donors.
The levels of cytokines in patients with mild AA did not differ from controls (p>0.05). Significant lowering of IL-2 (p<0.05) and IL-4 (p<0.01) was noted in patients with severe AA. TNF-a in patients with both forms of AA did not differ from that in controls. However, TNF-a was lower in patients with severe form of AA than in patients with mild form (p<0.05). Similarity of the levels of IL-2 and IL-4 in controls and patients with mild AA possibly implies, that dysbalance in the activity of Th-1 and Th-2 cells has not developed yet in this group of patients. Lowering of IL-2 and IL-4 in patients with severe forms of AA may be an indirect confirmation of autoimmunity mechanisms participation in the pathogenesis of these forms of AA. More expressed lowering of IL-4 in these patients as compared to IL-2 may indicate the decrease in functional activity of Th-cells, mostly of Th-2-cells. Similar levels of TNF-a in patients with both forms of AA and controls may indirectly indicate the absence of systemic immunopathological reactions in patients with AA. However the lowering of TNF-a level in patients with severe form of AA as compared in the mild form may indicate the tendency to formation of immunodeficiency in patients with severe AA. Differences in the levels of Th-specific cytokines in patients with mild and severe forms AA have been revealed. Lowering of IL-2 and IL-4 levels in patients with severe form implies the increase of dysbalance of immunoregulatory cells. Most probably the nature of those changes is compensatory.