Hidden immune environment uncovered in thymuses of myasthenia gravis patients

Northwestern Medicine researchers have discovered an unseen immune environment within the thymus of myasthenia gravis (MG) patients, which could contribute to the chronic autoimmune disease. The thymus, a small organ crucial for immune system development, appears to create a unique environment that sustains the disease after treatment, including thymectomy, the surgical removal of the thymus.

This discovery, published in Science Advances, may lead to new avenues for research and treatment. Using an extensive cellular and spatial map of the MG thymus, scientists identified specialized immune cells and survival signals that may sustain the disease. The thymus, once responsible for training immune cells during childhood, malfunctions in adulthood, potentially leading to MG.

The study of 23 thymus samples from 16 patients revealed a diverse population of class-switched B cells grouped within and around abnormal germinal centers, relying on survival signals from the tissue environment. These findings suggest that the thymus may create an abnormal immune environment that helps certain B cells survive and persist in MG patients, providing a new framework for understanding and treating the disease.