Pure red-cell aplasia: a review.

Pure red-cell aplasia is an anemia characterized by a near absence of nucleated red blood cells. It can be congenital or acquired. The congenital form is probably induced by intrauterine damage to early erythroid stem cells. The acquired form can be transient and self-limited or sustained and lifelong. Many, if not most, cases of transient pure red-cell aplasia are caused by the B19 parvovirus, which has a special affinity for erythroid progenitor cells. When complicating an underlying hemolytic anemia, the anemia may be acute and severe. Sustained aplasia is caused by viral invasion, immune rejection or toxic destruction of progenitor or precursor cells. It occurs most often in patients with a benign or malignant lymphoid disease. Treatment with immunosuppressive drugs--especially corticosteroids--will in most cases cause a temporary or permanent remission. The final outcome depends primarily on the underlying disorder.