Serum ferritin protein is an acute phase reactant, We hypothesized tha
t serum ferritin protein generated in response to an inflammatory proc
ess would have much less iron (Fe) in it than would ''normal'' ferriti
n protein, and therefore measuring serum ferritin iron would assess hu
man body iron status unconfounded by inflammation. Basic Methods. We m
easured serum ferritin iron in 140 clinical samples obtained from the
serum banks of Bronx VA Medical Center Hematology and Nutrition Labora
tory (Bronx, NY), the CDC Nutritional Biochemistry serum sample bank (
Atlanta, GA), and the sample bank from patients with thalassemia and i
ron overload treated at New York Hospital (New York, NY), Each was ana
lyzed for three conventional criteria of iron status: serum iron, perc
entage of transferrin saturation and ferritin protein. In addition, te
sts for inflammation were also performed: C-reactive protein, WBC and
transaminases, Seventy-seven patients' sera from 140 screened met each
of three consistent criteria for stages of iron status. Serum ferriti
n was immobilized by immunoprecipitation with rabbit antihuman polyclo
nal antibody bound to agarose and separated from other iron-containing
proteins, digested with 0.2 mi of 3N nitric acid and analyzed for iro
n content by atomic absorption spectroscopy. Results. Serum ferritin i
ron ranged in normal controls from 10 ng to 35 ng Fe/ml. The patients
with iron deficiency (4/4) and those in negative iron balance (5/6) ha
d values less than or equal to 10 ng, Positive iron balance (8/9) and
iron overload (22/22) values were >35 ng/ml, in contrast to 11/19 with
inflammation, Seventeen of twenty-two with overload had values >100 n
g/ml while only 1/19 with inflammation had such a value, Ferritin iron
in ferritin protein was >15% by weight in 14/22 with iron overload bu
t in 0/19 with inflammation, Implications of the Work. Serum ferritin
iron is a simple, direct measure of iron stores that we propose, in co
njunction with measuring serum ferritin protein, as a minimally invasi
ve screening procedure for accurately assessing the whole range of hum
an body iron status, unconfounded by inflammation.