Effect of specific antibodies on chronic echovirus type 5 encephalitis in a patient with hypogammaglobulinemia

The effects of specific antibodies in chronic echovirus type 5 (echo 5) encephalitis were investigated in a patient with x-linked hypogammaglobulinemia. Virus was detected in cerebrospinal fluid (CSF) and blood despite treatment with commercial human gammaglobulin that contained low titers of antibodies to echo 5 (0.6 × 10⁴ units per injection). Virus disappeared from blood and CSF when plasma containing high concentrations of antibodies (total dose, 1-4 × 10⁴ units/kg) was administered intravenously. Maximal inhibition of virus was achieved in culture and in the patient’s CSF when the titer of antibody to echo 5 in CSF was ≥ 16 units/ml. Although the patient died, hyperimmune plasma improved the neurologic status and eliminated detectable virus from the blood and CSF.