[Number of memory T cells in myasthenia gravis]

To determine the altered number of memory T cells in myasthenia gravis (MG) patients and confirmed the existence of immune memory disorder.

A total of 27 MG cases (12 females, 15 males) undergoing expanded thymectomy at our hospital between 2009-2012. They were divided into 3 group of eutherapeutic (clinical relative score ≥ 50%), invalid (clinical relative score ≤ 25%) and improved (25% < clinical relative score <50%). Control group was composed of 17 cases of healthy subjects without immune system related disease. Flow cytometry was employed to detect the numbers of CD4⁺, CD8⁺, CD4⁺ CD45RO⁺, CD8⁺ CD45RO⁺, CD4⁺ CD45RO⁺ CCR7⁺, CD8⁺ CD45RO⁺ CCR7⁺, CD4⁺ CD45RO⁺ CD44(high) and CD8⁺ CD45RO⁺ CD44(high) T cells in PBMCs of 27 MG patients and 17 normal controls.

As compared with healthy controls, the abnormal rates of CD4⁺ and CD8⁺ T cells were significantly higher in patients (P < 0.05), the number of CD4⁺ CD45RO⁺ CCR7⁺ T cells was significantly higher [(9.9 ± 5.5)% vs (6.6 ± 3.0)%, P = 0.012], the number of CD4⁺ CD45RO⁺ CD44(high) T cells was significantly higher [(6.8 ± 2.4)% vs (5.0 ± 3.0)%, P = 0.04] and the number of CD8⁺ CD45RO⁺ CCR7⁺ T cells was also significantly higher (P < 0.001).

MG patients had immune disorders. And increased number of memory T cells and their activation may be pathogenesis of MG.