Iron Metabolism Case Study
A 54-year old man complains of weakness, lassitude, and moderate weight loss (20 kg in the previous 7 mo). Pulse and respiratory rates were normal, as were the electrocardiographic and chest roentgenographic studies. Blood pressure was 145/75 mm Hg. The liver was firm and moderately enlarged, and the spleen was palpable. The patient remarked that his skin had become darker during the past few years, a change he attributed to time spent outdoors. The patient denied exposure to toxic chemicals or metal fumes. Laboratory results were as follows:
Fasting serum glucose
100 mg/dL (5.6 mmol/L)
Random urine glucose
Normal
Hemoglobin
17 g/dL (2.55 mmol/L)
Hematocrit
52%
Methemoglobin
Not detectable
Serum iron
2.4 mg/dL (43 umol/L)
Total serum iron-binding capacity
3.14 mg/dL (56 umol/L); ~77% saturation
Total serum bilirubin content
1.17 mg/dL (20umol/L)
On the basis of these observations, a biopsy of the liver was performed. Microscopic examination revealed fatty vacuolization of the hepatocytes and moderate deposits of hemosiderin in the cytoplasm of the cells. A diagnosis of hemochromatosis was made; the iron overload was later confirmed by a differential deferoxamine test.
BIOCHEMICAL QUESTIONS:
Define specialized terms.
Note the significance of quantities given and compare to normal values.
What foodstuffs are particularly rich sources of iron? Should this patient be advised to avoid these?
In what form is iron absorbed from the gastrointestinal tract? How is this absorption regulated?
How is iron transported in the blood? What proteins are involved in iron transport and storage?
What is the normal disposition of excess iron?
Explain why repeated phlebotomy is used to reduce the body burden of iron.
Iron Metabolism Case Study
A 54-year old man complains of weakness, lassitude, and moderate weight loss (20 kg in the previous 7 mo). Pulse and respiratory rates were normal, as were the electrocardiographic and chest roentgenographic studies. Blood pressure was 145/75 mm Hg. The liver was firm and moderately enlarged, and the spleen was palpable. The patient remarked that his skin had become darker during the past few years, a change he attributed to time spent outdoors. The patient denied exposure to toxic chemicals or metal fumes. Laboratory results were as follows:
| Fasting serum glucose | 100 mg/dL (5.6 mmol/L) |
| Random urine glucose | Normal |
| Hemoglobin | 17 g/dL (2.55 mmol/L) |
| Hematocrit | 52% |
| Methemoglobin | Not detectable |
| Serum iron | 2.4 mg/dL (43 umol/L) |
| Total serum iron-binding capacity | 3.14 mg/dL (56 umol/L); ~77% saturation |
| Total serum bilirubin content | 1.17 mg/dL (20umol/L) |
On the basis of these observations, a biopsy of the liver was performed. Microscopic examination revealed fatty vacuolization of the hepatocytes and moderate deposits of hemosiderin in the cytoplasm of the cells. A diagnosis of hemochromatosis was made; the iron overload was later confirmed by a differential deferoxamine test.
BIOCHEMICAL QUESTIONS:
Define specialized terms.
Note the significance of quantities given and compare to normal values.
What foodstuffs are particularly rich sources of iron? Should this patient be advised to avoid these?
In what form is iron absorbed from the gastrointestinal tract? How is this absorption regulated?
How is iron transported in the blood? What proteins are involved in iron transport and storage?
What is the normal disposition of excess iron?
Explain why repeated phlebotomy is used to reduce the body burden of iron.
