Immunotherapy of respiratory syncytial virus pneumonia following bone marrow transplantation.

Respiratory syncytial virus (RSV) pneumonia is a well-recognized complication of bone marrow transplantation with a high mortality rate. We describe two patients who developed RSV pneumonia within the first 3 weeks following allogeneic bone marrow transplantation. These patients had significant oxygen requirements and radiographic infiltrates. Both were treated with aerosolized ribavirin and given a single 1.5 gm/kg dose of intravenous immune globulin containing high levels of RSV neutralizing activity (RSV-IG). Both patients showed subjective and objective improvement after RSV-IG, never required mechanical ventilation, and were discharged without an oxygen requirement within 2 weeks after therapy. RSV microneutralization activity was measured in serum and nasal secretions. Mean serum microneutralization activity increased from 2279 microneutralization units (Mu)/ml to 18082 Mu/ml after RSV-IG. Peak serum microneutralization activity achieved with RSV-IG was higher than that achieved in a series of other immunocompromised adults with RSV pneumonia given either multiple doses of standard IVIG or no immune globulin therapy. RSV-IG may be beneficial in the treatment of RSV pneumonia in severely immunocompromised patients.