Abstract
Chronic fatigue syndrome is associated with systemic and cognitive symptoms and with several immune abnormalities. The clinical impact of Isoprinosine(r) was evaluated in sixteen CFS patients, followed for 28 weeks in a single-blind, placebo controlled trial. Patients were also monitored for various immune parameters. Improvement based on clinical staging was observed in six of ten treated patients (60%). Clinically improved patients showed significantly enhanced natural killer (NK) cell activity, which correlated with the duration of Isoprinosine treatment (p >0.03). Treatment with Isoprinosine resulted in significantly increased numbers of CD4+ T helper cells (p >0.03). Treatment with Isoprinosine for 12 weeks did not appreciably influence the in vitro production of IFN-y, IL-1oc, IL-10 or IL-12. However, IL-12 was significantly increased at week 28 (p >0.02) in patients who improved after treatment with Isoprinosine. These results suggest that taking Isoprinosine may benefit a subgroup of patients with CFS, and this clinical improvement is associated with enhanced NK cell function and IL-12 levels. Further trials to evaluate the use of Isoprinosine in the treatment of CFS patients are warranted.