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CASE REPORT article

Front. Immunol.
Sec. Multiple Sclerosis and Neuroimmunology
Volume 15 - 2024 | doi: 10.3389/fimmu.2024.1478777

Thymic hyperplasia after autologous hematopoietic stem cell transplantation in multiple sclerosis: a case series

Provisionally accepted
Alice Mariottini Alice Mariottini 1,2*Riccardo Boncompagni Riccardo Boncompagni 2Diletta Cozzi Diletta Cozzi 2Edoardo Simonetti Edoardo Simonetti 2Anna Maria Repice Anna Maria Repice 2Valentina Damato Valentina Damato 1Mirella Giordano Mirella Giordano 2Vittorio Miele Vittorio Miele 2Chiara Nozzoli Chiara Nozzoli 2Luca Massacesi Luca Massacesi 1
  • 1 University of Florence, Florence, Italy
  • 2 Careggi University Hospital, Florence, Tuscany, Italy

The final, formatted version of the article will be published soon.

    Introduction: Reactivation of thymopoiesis in adult patients with autoimmune disorders treated with autologous haematopoietic stem cell transplantation (AHSCT) is supported by studies exploring immunoreconstitution. Radiological evidence of thymic hyperplasia after AHSCT was previously reported in patients with systemic sclerosis, but, to our knowledge, it has not been described in multiple sclerosis (MS), where premature thymic involution has been observed and immunosenescence might be accelerated by disease-modifying treatments (DMTs). Participants and methods: monocentric case series including MS patients who performed a chest CT scan for clinical purposes after having received AHSCT (BEAM/ATG regimen) for aggressive MS failing DMTs. Chest CT exams were reviewed by a thoracic radiologist: thymic hyperplasia was defined as a rounded mass in the thymic loggia with a density around 40 Hounsfield Units (HU) and thickness >1.3 cm. Results. Fifteen MS patients were included; the median time interval between AHSCT and chest CT scan was 2 (range 1-18) months. All the patients were free from new inflammatory events and DMTs over a median follow-up of 36 months (range 12-84) after AHSCT. Thymic hyperplasia was detected in 3/15 (20%) cases in an exam taken 1 to 3 months after AHSCT; all these patients were females, and aged 30 to 40 years. Lung infections and secondary autoimmunity were diagnosed in 5 and 1 cases, respectively, none of which showed thymic hyperplasia. No associations between thymic hyperplasia and clinical-demographic characteristics or post-AHSCT outcomes were observed. Conclusions. Thymic hyperplasia was detected in 20% of MS patients recently treated with AHSCT. These results are consistent with previous immunological studies suggesting that AHSCT promotes thymus reactivation in MS patients, further supporting de-novo thymopoiesis as a cornerstone of immune reconstitution after AHSCT in this population.

    Keywords: Multiple Sclerosis, Hematopoietic Stem Cell Transplantation, transplant, Thymus, Immune reconstitution, Autoimmune Diseases, CT, imaging

    Received: 10 Aug 2024; Accepted: 05 Nov 2024.

    Copyright: © 2024 Mariottini, Boncompagni, Cozzi, Simonetti, Repice, Damato, Giordano, Miele, Nozzoli and Massacesi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Alice Mariottini, University of Florence, Florence, Italy

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