Leukocyte production of IFN-γ and TNF-α in 8- to 12-y-old children with low serum iron levels

•Low serum iron (LSI) was present in 17.5% of 8- to 12-y-old children in our sample.•Leukocyte numbers were significantly increased in children from the LSI group.•Neutrophil frequency and numbers were increased in the LSI group; lymphocyte frequency was reduced.•Interferon (IFN)-γ serum concentrations and production by peripheral blood mononuclear cells were reduced in the LSI group.•LSI correlates with decreased production of IFN-γ and altered leukocyte populations.