PREDICTORS OF OUTCOME Predictors of improvement were found to lie in immunologic measures recorded at entry, particularly a lowed CD4 lymphocyte count: “supporting the concept that cellular immunity is important in both the pathogenesis and response to treatment in patients with CFS.” The analysis conducted implies that ME/CFS patients who have scope to benefit from IgG may be predicted in advance with a high degree of accuracy. The gene discussed is CD4; the disease is myalgic encephalomeyelitis/chronic fatigue syndrome.