Characterization of CD4+ and CD8+ Tregs in a Hodgkin's lymphoma patient presenting with myasthenia-like symptoms.

The co-occurrence of Hodgkin's lymphoma (HL) and myasthenia gravis (MG) is a rare phenomenon that is sometimes considered a paraneoplastic manifestation. There are a few documented cases in which myasthenia symptoms manifested only after the surgical removal of the tumor. However, the biological basis of this association is unknown. One hypothesis is that it derives from the infiltration of the residual thymic tissue by the developing tumor. In our case, the myasthenic symptoms led to the HL diagnosis. Our objective was to investigate the T cell phenotype in a HL patient presenting myasthenia-like symptoms. In patients with autoimmune disease, Tregs are usually decreased, but in some diseases, they appear to be increased. It has been speculated that this phenomenon may occur due to a homeostatic attempt by the immune system to control the expansion of auto-reactive effector cells. In the described patient the proportion of lymphoma infiltrating Tregs was high (more than 10% of CD4+ and 1.34% of CD8+ cells), suggesting that Tregs are increased in patients suffering from HL and eventually of myasthenia gravis. Treg involvement in HL is controversial and is currently under investigation. In this context, our data may contribute to a better understanding of the underlying mechanism of the link between HL and autoimmune phenomena.