Scientific Reports (Jun 2024)

Comparison of juvenile and adult myasthenia gravis in a French cohort with focus on thymic histology

  • Frédérique Truffault,
  • Ludivine Auger,
  • Nadine Dragin,
  • Jean-Thomas Vilquin,
  • Elie Fadel,
  • Vincent Thomas de Montpreville,
  • Audrey Mansuet-Lupo,
  • Jean-François Regnard,
  • Marco Alifano,
  • Tarek Sharshar,
  • Anthony Behin,
  • Bruno Eymard,
  • Francis Bolgert,
  • Sophie Demeret,
  • Sonia Berrih-Aknin,
  • Rozen Le Panse

DOI
https://doi.org/10.1038/s41598-024-63162-0
Journal volume & issue
Vol. 14, no. 1
pp. 1 – 10

Abstract

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Abstract Myasthenia gravis (MG) is an autoimmune disease characterized by muscle fatigability due to acetylcholine receptor (AChR) autoantibodies. To better characterize juvenile MG (JMG), we analyzed 85 pre- and 132 post-pubescent JMG (with a cutoff age of 13) compared to 721 adult MG patients under 40 years old using a French database. Clinical data, anti-AChR antibody titers, thymectomy, and thymic histology were analyzed. The proportion of females was higher in each subgroup. No significant difference in the anti-AChR titers was observed. Interestingly, the proportion of AChR+ MG patients was notably lower among adult MG patients aged between 30 and 40 years, at 69.7%, compared to over 82.4% in the other subgroups. Thymic histological data were examined in patients who underwent thymectomy during the year of MG onset. Notably, in pre-JMG, the percentage of thymectomized patients was significantly lower (32.9% compared to more than 42.5% in other subgroups), and the delay to thymectomy was twice as long. We found a positive correlation between anti-AChR antibodies and germinal center grade across patient categories. Additionally, only females, particularly post-JMG patients, exhibited the highest rates of lymphofollicular hyperplasia (95% of cases) and germinal center grade. These findings reveal distinct patterns in JMG patients, particularly regarding thymic follicular hyperplasia, which appears to be exacerbated in females after puberty.

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