[Relationship between expression of Cat V and clinicopathologic character of myasthenia gravis in patients with thymoma].

OBJECTIVE

To investigate the association of expression of Cat V with the clinicopathologic variables of myasthenia gravis (MG) in patients with thymoma.

METHODS

Seventy-eight patients with thymomas were involved. Immunohistochemical method was adopted in investigating the protein expression of Cat V in the thymomas and thymic tissues adjacent to thymomas.

RESULTS

The protein of Cat V could be detected in both thymomas and thymic tissues. And the cortex was the main expressive domain of Cat V in thymus. The positive ratio of Cat V expression in thymoma was significantly increased in patients with MG, compared with that in patients without MG (82.50% vs 26.33%, P < 0.01), and similar results were observed in thymic tissues adjacent to tumors (77.50% vs 31.58%, P < 0.01). Analysis on the relationship of the clinical subtypes of MG with expression of Cat V revealed that the positive ratio in type II (92.00%) and type III (83.33%) was much higher than that in type I (55.56%) (P < 0.05). The expression of Cat V was significantly raised in the epithelial-rich and mixed cell thymomas when compared with that in the lymphocyte-rich ones. No statistically significant difference was found on the variables such as perioperative myasthenic crisis, sex or age of patient, duraton of sickness and expression of Cat V.

CONCLUSION

The overexpression of Cat V in thymomas may be associated with MG.