Question

All are increased in Iron Deficiency Anemia (IDA) except?

• A. TIBC
• B. Soluble transferrin receptor
• C. Transferrin saturation
• D. Erythropoietin

Hint:

Consider which iron study parameter falls when serum iron is low and TIBC is high.

Answer 1

The Correct Option is C

Step 1: Understand Iron Deficiency Anemia (IDA). IDA results from inadequate iron supply for erythropoiesis. The body responds by upregulating iron absorption and transport mechanisms.

Step 2: Evaluate each parameter in IDA.
- TIBC (Total Iron Binding Capacity): Increased. When serum iron is low, the liver produces more transferrin, raising TIBC.
- Soluble transferrin receptor (sTfR): Increased. sTfR is elevated in tissue iron deficiency as cells upregulate transferrin receptors to capture more iron.
- Transferrin saturation: DECREASED. Transferrin saturation = (serum iron / TIBC) x 100. In IDA, serum iron is low and TIBC is high, so saturation falls. This is the exception among the listed options.
- Erythropoietin (EPO): Increased. The kidney releases more EPO in response to anemia and tissue hypoxia.

Conclusion: Transferrin saturation is the only parameter that decreases in IDA; all others increase.