A Pennsylvania State University study of 72 seemingly healthy women, aged 60 or more, focused on how iron deficiency impaired their measures of immunity. The group of women was well-nourished, homebound and living in three rural Pennsylvania counties.

Blood samples provided by the participants identified the women as iron deficient if their iron stores were depleted and they had abnormal results on two or more other iron status tests.

Cells from the samples of both the iron-deficient and iron-sufficient women were subjected to several immune response tests. In one test, white T-cells were stimulated with two chemicals that simulate response to infection in the body. Normally, the T-cells respond by multiplying. However, in the iron-deficient women, the T-cell response was only 40% to 50% of that of the iron-sufficient women.

In another test, white blood cells called granulocytes were exposed to bacteria. Usually, the granulocytes ingest bacteria and kill them with an oxidative burst. While the granulocytes ingested the bacteria at the same rate in the iron-deficient women, the magnitude of the oxidative burst was 28%, suggesting a potentially reduced capacity to kill the bacteria. The Pennsylvania State University, Barbara Hale, 814-865-9481, bah@psu.edu