Intravenous immunoglobulin for suspected or proven infection in neonates

Neonates are at higher risk of infection due to immuno-incompetence. Maternal transport of immunoglobulins to the fetus mainly occurs after 32 weeks' gestation, and endogenous synthesis begins several months after birth. Administration of intravenous immunoglobulin (IVIG) provides immunoglobulin G (IgG) that can bind to cell surface receptors, provide opsonic activity, activate complement, promote antibody-dependent cytotoxicity and improve neutrophilic chemo-luminescence. Theoretically, infectious morbidity and mortality could be reduced by the administration of IVIG.

To assess the effects of IVIG on mortality and morbidity caused by suspected or proven infection at study entry in neonates. To assess in a subgroup analysis the effects of IgM-enriched IVIG on mortality from suspected infection.

For this update, MEDLINE, EMBASE, The Cochrane Library, CINAHL, trial registries, Web of Science, reference lists of identified studies, meta-analyses and personal files were searched in 2013. No language restrictions were applied.

Randomised or quasi-randomised controlled trials involving newborn infants (< 28 days old); IVIG for treatment of suspected or proven bacterial or fungal infection compared with placebo or no intervention; and where one of the following outcomes was reported, mortality, length of hospital stay or psychomotor development at follow-up.

Statistical analyses included typical risk ratio (RR), risk difference (RD), weighted mean difference (WMD), number needed to treat for an additional beneficial outcome (NNTB) or an additional harmful outcome (NNTH), all with 95% confidence intervals (CIs), and the I² statistic to examine for statistical heterogeneity.

The updated search identified one published study that was previously ongoing. A total of 9 studies evaluating 3973 infants were included in this review. Mortality during hospital stay in infants with clinically suspected infection was not significantly different after IVIG treatment (9 studies (n = 2527); typical RR 0.95, 95% CI 0.80 to 1.13; typical RD -0.01, 95% CI - 0.04 to 0.02; I² = 23% for RR and 29% for RD). Death or major disability at 2 years corrected age was not significantly different in infants with suspected infection after IVIG treatment (1 study (n = 1985); RR 0.98, 95% CI 0.88 to 1.09; RD -0.01, 95% CI -0.05 to 0.03). Mortality during hospital stay was not significantly different after IVIG treatment in infants with proven infection at trial entry (1 trial (n = 1446); RR 0.95, 95% CI 0.74 to 1.21; RD -0.01, 95% CI -0.04 to 0.03). Death or major disability at 2 years corrected age was not significantly different after IVIG treatment in infants with proven infection at trial entry (1 trial (n = 1393); RR 1.03, 95% CI 0.91 to 1.18; RD 0.01, 95% CI -0.04 to 0.06). Mortality during hospital stay in infants with clinically suspected or proven infection at trial entry was not significantly different after IVIG treatment (1 study (n = 3493); RR 1.00, 95% CI 0.86 to 1.16; RD 0.00, 95% CI - 0.02 to 0.03). Death or major disability at 2 years corrected age was not significantly different after IVIG treatment in infants with suspected or proven infection at trial entry (1 study (n = 3493); RR 1.00, 95% CI 0.92 to 1.09; RD -0.00, 95% CI -0.03 to 0.03). Length of hospital stay was not reduced for infants with suspected or proven infection at trial entry (1 study (n = 3493); mean difference (MD) 0.00 days, 95% CI -0.61 to 0.61). No significant difference in mortality during hospital stay after administration of IgM-enriched IVIG for suspected infection at trial entry was reported in 4 studies (n = 266) (typical RR 0.68, 95% CI 0.39 to 1.20; RD -0.06, 95% CI -0.14 to 0.02; I² = 17% for RR and 53% for RD).

The undisputable results of the INIS trial, which enrolled 3493 infants, and our meta-analyses (n = 3973) showed no reduction in mortality during hospital stay, or death or major disability at two years of age in infants with suspected or proven infection. Although based on a small sample size (n = 266), this update provides additional evidence that IgM-enriched IVIG does not significantly reduce mortality during hospital stay in infants with suspected infection. Routine administration of IVIG or IgM-enriched IVIG to prevent mortality in infants with suspected or proven neonatal infection is not recommended. No further research is recommended.