Fig. 1.

T-lymphocyte subsets and cytokine interactions in AIHA. Cytokines that were found elevated are highlighted in yellow: IL-2 and IL-12, that induce the differentiation of CD4+ naïve T cells into Th1 subset, and IL-4, that promotes Th2 switch. Elevated levels of TGF-β favor the differentiation of Th17 subset, which amplifies the pro-inflammatory and autoimmune response. On the contrary, decreased levels of both IFN-γ and Tregs were found (highlighted in green). The former resulted in decreased inhibition of Th2 response, i.e. an amplification of the autoantibody-mediated autoimmune disease, and the latter may cause a lack of down-regulation of inflammatory and autoimmune pathways.