Which lab abnormality indicates bone marrow suppression due to azathioprine?

Which lab abnormality indicates bone marrow suppression due to azathioprine?

• A. Increased platelets
• B. Elevated bilirubin
• C. Normal white blood cell count
• D. Decreased white blood cell count

Answer: (D)

Azathioprine suppresses bone marrow by inhibiting DNA synthesis in rapidly dividing cells, so a drop in leukocytes reflects this myelosuppressive effect. A decreased white blood cell count indicates reduced production of immune cells, which is exactly what bone marrow suppression from azathioprine looks like and explains the increased infection risk. The other options point to different issues: elevated bilirubin suggests liver toxicity rather than marrow function; increased platelets don’t indicate suppression and would imply a different pattern of blood cell changes; a normal white blood cell count shows the marrow is functioning adequately. Regular monitoring of the complete blood count helps catch this suppression early so dosing can be adjusted to protect the patient.

Azathioprine suppresses bone marrow by inhibiting DNA synthesis in rapidly dividing cells, so a drop in leukocytes reflects this myelosuppressive effect. A decreased white blood cell count indicates reduced production of immune cells, which is exactly what bone marrow suppression from azathioprine looks like and explains the increased infection risk. The other options point to different issues: elevated bilirubin suggests liver toxicity rather than marrow function; increased platelets don’t indicate suppression and would imply a different pattern of blood cell changes; a normal white blood cell count shows the marrow is functioning adequately. Regular monitoring of the complete blood count helps catch this suppression early so dosing can be adjusted to protect the patient.