Association between postoperative peripheral blood CD3+ T-cell percentage and recurrence after thymectomy in non-thymomatous myasthenia gravis: a retrospective cohort study.

Postoperative recurrence remains an important concern in patients with myasthenia gravis (MG) after thymectomy. T-cell abnormalities are involved in MG pathogenesis, but the prognostic value of postoperative peripheral blood CD3+ T-cell percentage in non-thymomatous MG is unclear. We evaluated the association between postoperative peripheral blood CD3+ T-cell percentage and recurrence after thymectomy in patients with non-thymomatous MG. This retrospective cohort study used data from an existing MG thymectomy database. Patients with non-thymomatous MG who had available postoperative peripheral blood CD3+ T-cell percentage data and follow-up information were included. Patients were divided into low and high postoperative CD3+ T-cell groups according to the median value. Logistic regression was used to evaluate the association between postoperative CD3+ T-cell group and postoperative recurrence during follow-up, whereas time-to-event analyses were performed using Kaplan-Meier curves and Cox regression. The primary analysis included 275 patients, of whom 82 experienced postoperative recurrence. The low and high postoperative CD3+ T-cell groups included 136 and 139 patients, respectively. Recurrence occurred in 49 patients (36.0%) in the low postoperative CD3+ T-cell group and 33 patients (23.7%) in the high postoperative CD3+ T-cell group. In crude logistic regression, high postoperative CD3+ T-cell percentage was associated with lower odds of recurrence (OR=0.55, 95% CI [0.33, 0.93], p = 0.027). This association remained after adjustment for age at onset, sex, worst preoperative Myasthenia Gravis Foundation of America (MGFA) class, onset-to-thymectomy time, and preoperative immunotherapy (OR=0.57, 95% CI [0.33, 0.97], adjusted p = 0.037). In Cox regression, high postoperative CD3+ T-cell percentage showed a directionally consistent but statistically non-significant association with recurrence-free survival (HR=0.69, 95% CI [0.44, 1.08], adjusted p = 0.104). Sensitivity analyses generally supported the direction of the primary finding. In this retrospective cohort of patients with non-thymomatous MG after thymectomy, higher postoperative peripheral blood CD3+ T-cell percentage was associated with lower odds of postoperative recurrence. Time-to-event analyses showed a similar direction but did not reach statistical significance. These findings suggest that postoperative CD3+ T-cell percentage may be a clinically accessible marker associated with recurrence risk, but prospective validation is needed.