Fc-gamma receptor expression and cytokine response to intravenous human immunoglobulin in mothers and neonates

Objective The use of intravenous human immunoglobulin (IVIg) as adjuvant therapy for sepsis has been shown efficacious in adults, but its use in pregnant women and newborns is controversial. Fc gamma receptors (FcγRs) support the ability of IVIg to stimulate the synthesis of inflammatory mediators and promote phagocytosis by leukocytes, however, the FcγRs expression is differential between adults and neonates. We aimed to explore the effect of IVIg in monocytes and neutrophils from mother and neonates in whole blood cultures. Study design Whole blood from adults, maternal, and neonates were incubated with LPS and/or IVIg. After 0, 24, and 48 hours, we measured the expression of FcγRs (CD16, CD32, and CD64) and bacterial phagocytosis by monocytes and neutrophils. Also, the concentration of pro-inflammatory cytokines/chemokines was determined. Results FcγRs expression is quite similar among groups, and the LPS or IVIg challenge did not change the FcγRs expression on monocytes and neutrophils. Also, the LPS or IVIg challenge did not modify phagocytosis capacity in any group. However, IVIg induces a higher IL-8 response in neonates than in adults. Conclusion Our results suggest that the IL-8 response to IVIg in whole blood from neonates is not dependent on differential FcγR expression. Key messages IVIg challenge in neonates or adults does not induce FcγR change expression on monocytes or neutrophils IVIg induces higher IL-8 response in neonates than in adults