Adult Primary Immune Thrombocytopenia Spleen Histology Findings and Outcomes According to Rituximab Use Based on Analysis of 41 Cases

摘要

Immune thrombocytopenia (ITP) is an acquired antibody-mediated disease, for which splenectomy remains a curative treatment. We analyzed histology and phenotypes of ITP-splenectomy specimens from 41 adult patients, with different previous ITP-specific treatments, including B-cell-depleting rituximab (RTX) or not, in an attempt to predict splenectomy success or failure on the basis of day 56 postoperative platelet counts. RTX-naive ITP-spleen samples, compared with those from a 20-patient control trauma cohort, contained the following nonspecific, ITP-evocative, white-pulp lesions: follicular helper T-cell (programmed death-1(+) and inducible T-cell COS-timulator(+)) expansion in reactive follicles (P = 0.01 and 0.03, respectively) and regulatory T-cell (FOXP3(+)) expansion in the T-cell zone (P = 0.049). On comparing ITP-splenectomy samples that would be successful with those that would be failures, only marginal zone hyperplasia differed (P = 0.017). Indeed, 13/21 (61.9%) successful splenectomy samples exhibited marginal zone hyperplasia, as opposed to 1/9 (11.1%) failed splenectomy specimens. RTX impact on ITP-splenectomy samples was characterized by white-pulp (P = 0.03) and marginal zone atrophies (P = 0.01), and periarteriolar T-cell-zone hyperplasia (P0.0001). The results of this novel comparative study of the histologic patterns of 41 ITP patients' evocative splenic lesions enabled clear description of different ITP morphologies and phenotypes, as a function of prior treatment and splenectomy success or failure.