Bone Marrow Failure Syndromes

Bone marrow failure means the marrow cannot produce enough blood cells to meet the body's needs. The most clinically important pattern is pancytopenia: reduced red blood cells, neutrophils, and platelets. Acquired aplastic anemia is a prototypical marrow-failure syndrome. Immune-mediated injury destroys or suppresses hematopoietic stem cells, so the marrow becomes markedly hypocellular and releases too few mature cells into circulation. The resulting findings are not three unrelated problems. They are three consequences of one production failure: - Too few red cells reduce oxygen delivery, causing fatigue, weakness, pallor, exertional dyspnea, dizziness, and sometimes tachycardia or chest discomfort. - Too few neutrophils weaken the first cellular defense against infection. Fever may be the only obvious sign because a neutropenic patient may not generate pus, erythema, or a strong leukocytosis. - Too few platelets impair primary hemostasis, producing petechiae, easy bruising, epistaxis, bleeding gums, heavier menstrual bleeding, or blood in the urine, stool, or emesis. The bedside pattern matters more than any single symptom. A patient with fatigue alone may have anemia from many causes; fatigue plus recurrent fever and mucosal bleeding...