Post-thymectomy combined treatment of prednisone and tacrolimus versus prednisone alone for consolidation of complete stable remission in patients with myasthenia gravis: a non-randomized, non-controlled study

Background: Thymectomy is a standard treatment of myasthenia gravis (MG). Immunomodulating agents are frequently given during the post-thymectomy latency period until complete remission is fully consolidated.Objective: A single-centre, non-randomized, non-controlled study was conducted to compare rates of complete stable remission (CSR) to post-thymectomy early treatment with prednisone alone or prednisone combined with tacrolimus, in 80 patients with MG.Methods: Thirty-nine consecutive patients underwent elective transsternal extended thymectomy in 1997–1999 and received prednisone alone (1.5 mg/kg/day) postoperatively, whereas 41 patients operated on in 2000–2002 received prednisone combined with tacrolimus (0.1 mg/kg per day b.i.d. starting 24 hours after thymectomy).Results: The mean follow-up was 59 months (SD 32.9) in the prednisone group and 35.9 months (SD 17.1) in the tacrolimus group ( p = 0.003). CSR was achieved in 47.5% of patients in the tacrolimus group and in 41.0% in the prednisone group ( p = 0.60). The estimated median follow-up to obtain a CSR in non-thymomatous MG was 38.2 months (95% confidence interval [CI] 30.1–46.4 months) for the tacrolimus group and 64.6 months (95% CI 50.9–78.2 months) for the prednisone group, and in patients with hyperplasia, 32.2 months (95% CI 23–41.5 months) and 62.9 months (95% CI 45.7–80.1 months), respectively (log-rank test, p = 0.03). The behavior of the two study groups stratified by thymic histology were significantly different (log-rank test, p = 0.006).Conclusions: Post-thymectomy administration of tacrolimus combined with prednisone was more effective than prednisone alone for the consolidation of CSR in a substantially shorter period of time in patients with MG.