In Reply. —
We agree with Dr Hermann that the cause of elevated antibody to EBV early antigen in some patients with chronic fatigue remains unexplained. However, the results of our study showed that measurement of antibody to EBV early antigen, as it is being used by clinicians in the evaluation of patients with chronic fatigue, was of no practical value. The symptoms, physical examination findings, laboratory evaluation, and subsequent course of patients with chronic fatigue were unrelated to antibody to EBV early antigen.We agree with the general content of the letter by Dr Reiss. We note that the sentence to which he refers begins, "In our opinion...." With what is now known, and unknown, about EBV, EBV serologies, and chronic fatigue, we believe that measurement of antibody to early antigen is of little practical value in the evaluation of patients with chronic fatigue. In our estimation, the burden