Immunoglobulin treatment for respiratory syncytial virus infection

Abstract

Background: Respiratory syncytial virus (RSV) bronchiolitis and pneumonia hospitalize hundreds of thousands of infants every year. Treatment is largely supportive therapy, (for example, oxygen, fluids and occasionally mechanical ventilation). Ribavirin, an antiviral agent, is licensed for severe RSV infection, although systematic reviews find it of no benefit. Passive protection against RSV can be achieved through monthly intramuscular injection of the humanized monoclonal anti-RSV antibody palivizumab (Synagis), and yields a 55% reduction in RSV hospitalisation in susceptible infants. This review assesses immunoglobulin treatment of RSV infection rather than its role as a prophylactic measure.

Objectives: To assess the efficacy of adding human or humanized immunoglobulin therapy to supportive therapy in infants hospitalized with laboratory-determined RSV infection.

Search strategy: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 1, 2006), MEDLINE (1966 to Week 4, January 2006) and EMBASE (1980 to September 2005). We also ran searches of reference lists of relevant trials and review articles and searches of personal files. We did not impose any language restrictions.

Selection criteria: We selected randomised controlled trials (RCTs) that compared immunoglobulin treatment with a placebo control in children hospitalized for RSV infection with bronchiolitis or pneumonia or other lower respiratory tract infection (LRTI) with laboratory-documented RSV infection. The primary outcomes of interest were mortality, length of hospitalisation, length of ventilation and oxygen dependence. Secondary outcome measures were pulmonary function and re-hospitalisations for recurrent breathing difficulties in subsequent years. Any adverse effects of the treatments were also noted, for example, hypersensitivity reactions.

Data collection and analysis: Data were extracted but cross-comparison was not possible due to the shortage of studies and lack comparative measurements.

Main results: Four papers fitted the search criteria. None demonstrated statistically significant benefit of intravenous immunoglobulin (IVIG) treatment added to supportive care compared with supportive care alone. The evidence does not support a role for RSVIG in such a setting, with the doses used in the studies.

Authors' conclusions: The evidence on the role of respiratory syncytial virus immunoglobulin (RSVIG) in treating RSV severe infections is limited. Future research might consider using stronger titres of neutralising antibodies; and further analyse severely ill children (who might respond differentially compared to those less ill, but yet hospitalised).