Which of the following is a cause of decreased platelet production?

Which of the following is a cause of decreased platelet production?

• A. ITP
• B. Marrow infiltration
• C. TTP
• D. Hepatic cirrhosis

Answer: (B)

Platelet production occurs in the bone marrow from megakaryocytes. When the marrow is infiltrated by malignant cells, fibrosis, or other disease processes, the normal hematopoietic environment is displaced and megakaryocyte development is suppressed. This directly reduces the output of platelets, making marrow infiltration a classic cause of decreased platelet production. The other conditions mainly affect platelets after production or through distribution. Immune destruction, as seen in immune thrombocytopenia, lowers platelet counts by removing platelets from circulation rather than by dampening production. Thrombocytopenia from thrombotic thrombocytopenic purpura results from platelet consumption in microthrombi, not from a failure of production. Liver disease, including cirrhosis, tends to cause low platelets primarily through splenic sequestration and sometimes reduced thrombopoietin production, rather than a primary failure of marrow production.

Platelet production occurs in the bone marrow from megakaryocytes. When the marrow is infiltrated by malignant cells, fibrosis, or other disease processes, the normal hematopoietic environment is displaced and megakaryocyte development is suppressed. This directly reduces the output of platelets, making marrow infiltration a classic cause of decreased platelet production.

The other conditions mainly affect platelets after production or through distribution. Immune destruction, as seen in immune thrombocytopenia, lowers platelet counts by removing platelets from circulation rather than by dampening production. Thrombocytopenia from thrombotic thrombocytopenic purpura results from platelet consumption in microthrombi, not from a failure of production. Liver disease, including cirrhosis, tends to cause low platelets primarily through splenic sequestration and sometimes reduced thrombopoietin production, rather than a primary failure of marrow production.