Iron deficiency, inflammatory processes and humoral immunity in children.

Indicators of iron status, markers of inflammatory processes, serum immunoglobulins and C3 and C4 components of complement were assessed in 142 children 10-months old. All the iron parameters and most of the indicators of humoral immunity were correlated with markers of inflammation. Sixty-two children presented biochemical indications of inflammation (high CRP or orosomucoid level, or hyperleukocytosis), while 80 children were free of it. In the latter group, the use of a combination of iron indicators enabled separation of iron-sufficient children from those with different degrees of iron deficiency, ranging from iron depletion to iron-deficiency anemia. Serum IgG and IgA were significantly lower only in the group of iron-depleted children. Serum ferritin was significantly positively correlated with IgA, IgM and C4. Iron depletion may be responsible for a decrease humoral immunity. This effect was not visible at more advanced stages of iron deficiency.