Factors influencing the relapse risk at steroid dose reduction in myasthenia gravis.

In a selected group of 69 patients with myasthenia gravis treated with prednisone, the factors were studied that might have influenced the reoccurrence or exacerbation of clinical signs after initial improvement in two-thirds of the patients. It was not evident that the speed of dose reduction was responsible for the relapse in most patients. Azathioprine added to the prednisone regimen was found to reduce the relapse rate at steroid reduction. Pure ocular cases and patients who underwent thymectomy without thymoma had a higher chance to remain in remission after prednisone was stopped. Maintenance dose could be determined in 18 patients and was 0.42 mg/kg/2 d., but the difference between patients with or without azathioprine was not significant.