IMMUNOLOGICAL MONITORING OF AZATHIOPRINE TREATMENT IN MULTIPLE-SCLEROSIS PATIENTS

Despite the longstanding clinical use of azathioprine as an immunosupp ressive agent in multiple sclerosis, little is known about the action of this drug on a number of parameters of putative pathogenic relevanc e in the disease. Eleven patients with multiple sclerosis, treated wit h azathioprine 2.5-3 mg/kg per day, and six untreated patients were st udied with serial blood sampling for 1 year. The following immunologic al parameters were investigated: peripheral blood lymphocyte subsets, natural killer activity, serum IgG, IgM, ICAM-1 and tumour necrosis fa ctor alpha (TNF-alpha). The most relevant changes included a decrease in CD3-CD56(+) cells, an increase in CD4(+)CD45RA(+) cells and a decre ase in TNF-alpha levels only in treated patients, while no changes occ urred in untreated patients over a 1-year period. The decrease in TNF- alpha levels and the increase in ''suppressor-inducer'' lymphocytes co uld reduce chronic inflammation in multiple sclerosis, and paralleled an overall favourable clinical response to azathioprine treatment in o ur patients.