Patients with autoimmune thrombocytopenic purpura (ITP) over the age of 60 appear to have an aberrant regulatory T cell proinflammatory plasticity skewed towards a Th17 paradigm. This finding could lead to the development of new therapeutic alternatives for these patients, according to a recently published study in BMC Immunology.

ITP is characterized by platelet destruction by antiplatelet antibodies in the context of a Th1/Th17 differentiation with a deficient regulatory T cell functionality. Despite the growing interest in the role of immune senescence in several autoimmune diseases, there is scarce literature regarding its role in patients with ITP over the age of 60.

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“Tregs play vital roles in the maintenance of immune homeostasis, the inhibition of immune responses, and the establishment of self-tolerance,” the authors wrote. “In different inflammatory milieu, Tregs are capable of co-expressing effector Th markers including interferon-γ (IFN-γ), interleukin-13 (IL-13), and interleukin-17 (IL-17).”

The authors aimed to provide a new perspective into the pathogenesis of ITP by further assessing the proinflammatory plasticity of regulatory T cells in patients with ITP over the 6th decade of life.

The retrospective study included over 90 patients with primary ITP. Patients were divided into 2 groups according to age. Peripheral blood samples of the included population were analyzed through flow cytometry and by routine polymerase chain reaction procedure and compared to samples of a healthy control group.

Patients with ITP had significantly interleukin 17 expressions than the healthy control group as well as markedly decreased gamma interferon and interleukin 13. Comparison among age groups revealed that older patients with ITP had higher interleukin 17 levels and a decreased CD19+ B cell population. Similarly, the older population had significantly more TGFBR2 variants than the younger group.

“Primary ITP demonstrated skewed Treg plasticity towards a Th17 paradigm, which was further aggravated in elderly patients presenting ITP since their 6th decade of age,” the authors concluded.

Reference

Cao J, Zhan Y, Ji L, et al.Proinflammatory plasticity towards Th17 paradigm of regulatory T cells consistent with elevated prevalence of TGFBR2 variants in elderly patients with primary immune thrombocytopenia. BMC Immunol. Published online April 9, 2023. doi: 10.1186/s12865-023-00541-8