EXACERBATION OF MYASTHENIA-GRAVIS AFTER REMOVAL OF THYMOMAS

It appeared from this prospective and non-randomized study, that the r emoval of thymomas in myasthenia gravis (MG) patients resulted in rapi d exacerbation of the clinical severity of the disease and of anti-ace tylcholine receptor antibodies titres, which peaked after about 300 da ys and continued for up to 2 years. Long-term follow-up after thymomec tomy (mean duration +/- SEM after surgery 5.5 +/- 0.8 years) showed th at the immunological and clinical state observed prior to surgery was eventually restored, but long-term benefit attributable to surgery cou ld not be demonstrated. Non-thymoma MG cases, however, exhibited post- operative amelioration in clinical course and decreasing antibodies ti tres, both of which were already significant one year after surgery, a nd additional improvement was observed at the time of long-term follow -up (mean 4.3 +/- 0.5 years). Furthermore, the prognosis for MG patien ts not operated on was also favourable. It is suggested that the occur rence of thymomas is linked to genetic factors and that neoplasia of t he thymus may be part of immunoregulatory mechanisms with predominance of inhibition.