The diagnostic efficacy of hepatic computed tomography density (HCTD) in comparison with serum
ferritin for the detection of
iron overload was investigated in uremic patients on maintenance
hemodialysis (HD) and in patients with idiopathic
hemochromatosis (IHC). Ten IHC patients, 38 HD patients and 40 healthy subjects underwent the CT scanning of the liver and determination of percent saturation of
transferrin, serum
ferritin concentration and HLA typing. Liver
iron content was determined by histochemical grading and direct measurement of liver
iron concentration either in IHC patients or in HD patients. Nineteen HD patients were considered to have
iron overload on the basis of liver
iron concentration exceeding 3.6 mumol/100 mg dry weight. The mean +/- SD values of HCTD in healthy subjects, IHC patients, HD patients with
iron overload and without
iron overload were 60.2 +/- 5.6, 79 +/- 5.6, 71.4 +/- 3.6, 58 +/- 3.8 Hounsfield units, respectively. HCTD showed positive correlations with liver
iron concentration and serum
ferritin either in IHC patients or in HD patients. The analysis of the diagnostic efficacy of HCTD in comparison with serum
ferritin for the detection of excessive hepatic
iron in HD patients demonstrated that HCTD had higher sensitivity, specificity, positive and negative predictive values. Cut-off points were arbitrarily fixed to 66 Hounsfield units for HCTD, 400 micrograms/liter for serum
ferritin and 3.6 mumol/100 mg dry weight for liver
iron concentration. Seventeen HD patients who possessed the
histocompatibility antigens associated with IHC, namely
HLA-A3 and/or
HLA-B7 and/or
HLA-B14, had liver
iron concentration, serum
ferritin and HCTD values higher than those of the HD patients without these "
hemochromatosis alleles".(ABSTRACT TRUNCATED AT 250 WORDS)