Accessory spleens recapitulate the immune microenvironment of the main spleen in immune thrombocytopenia

Abstract

The spleen plays a key role in the pathogenesis of immune thrombocytopenia (ITP), as it is the main site of anti-platelet antibody production and T-cell-mediated autoimmune responses. 1 It is also involved in platelet pooling, sequestration and phagocytosis by red pulp macrophages. 1 These dysimmune processes are mediated by a complex interplay between immunologic triggers and immune mediators, including regulatory T cells (Treg), soluble cytokines, circulating microRNAs and surface immunoglobulin receptors on monocytes and histiocytes. 1,2 These immune functions justify the relevance of splenectomy as second-line therapy for ITP, with clinical response rates ranging from 50% to 70%. [3][4][5] Despite this, the recourse to splenectomy is progressively decreasing due to the risk of life-threatening complications, the long-term susceptibility to infections and the advent of alternative medical therapies. 5 To support therapeutic decisions, several studies have tried to identify clinical predictors of response to splenectomy. 6

Secondary spleen in immune thrombocytopenia: Not so accessory after all…

“…In their paper the authors 11 analysed, in eight patients with primary ITP, the different immune populations and their distribution within the main spleen and AcS removed during the same surgical procedure. They observed a similar appearance of the B cell areas represented by follicles Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder characterized by an isolated thrombocytopenia.…”

“…In their paper the authors 11 analysed, in eight patients with primary ITP, the different immune populations and their distribution within the main spleen and AcS removed during the same surgical procedure. They observed a similar appearance of the B cell areas represented by follicles and similar proportions of the different T‐cell populations involved in the pathophysiology of ITP, such as T follicular helper cells, Treg and cytotoxic T cells 1,2 .…”