Question

Erythrocyte Sedimentation Rate is zero in

• A. Abetalipoproteinemia
• B. Afibrinogenemia
• C. Asplenia
• D. Aplastic anemia

Hint:

Think about what protein is needed for red cells to stack into rouleaux.

Answer 1

The Correct Option is B

The ESR depends entirely on red cells clumping into rouleaux, and rouleaux formation needs fibrinogen in the plasma. Keeping this in mind, let's look at each option.

1. Abetalipoproteinemia: Here red cells become spiky acanthocytes because of abnormal lipid handling. This odd shape can reduce ESR a bit, but fibrinogen is still present, so ESR does not fall to zero.
2. Afibrinogenemia: In this rare inherited disorder, the plasma has almost no fibrinogen at all. Without fibrinogen there is nothing to glue red cells into stacks, so rouleaux cannot form and ESR reads as zero regardless of any inflammation.
3. Asplenia: Removing or losing the spleen changes red cell shape by allowing Howell Jolly bodies and target cells to persist, but plasma fibrinogen is unaffected, so ESR stays normal or can even rise.
4. Aplastic anemia: Bone marrow failure lowers the red cell count. Fewer red cells actually settle faster because there is less crowding, so ESR tends to go up here, not down to zero.

Since fibrinogen is completely missing only in afibrinogenemia, that is the one condition where rouleaux cannot form at all and ESR becomes zero.

Let's summarize:

• Rouleaux formation, and therefore ESR, depends on plasma fibrinogen.
• Total absence of fibrinogen is the only situation among these options that drops ESR to zero.

So the condition with a zero ESR is afibrinogenemia.