Diagnosis and management of red cell aplasia in children.

The vast majority of pediatric RBC hypoplastic anemias are accounted for by red blood cell aplasia associated with chronic hemolysis, Diamond-Blackfan anemia, and transient erythroblastopenia of childhood. However, other causes of hypoplastic anemia occur in children, and some of these are similar to what is seen in adult RBC aplasia. For example, it has been reported that a 5-year-old girl with an aregenerative anemia had a thymoma and later developed pancytopenia. RBC aplasia also has been seen in children receiving anticonvulsant drug therapy, children recovering from severe protein malnutrition, children with hepatitis, and in children with leukemia during maintenance therapy. In addition, it is not uncommon for pediatric hematologists to observe children with RBC aplasia where there is no obvious diagnosis, although many are considered to be variants of Diamond-Blackfan anemia. Several important questions about RBC hypoplastic anemias in children need to be resolved; it is hoped that this will be accomplished in the next decade. Do RBC hypoplastic crises associated with hemolytic anemia occur with viral infections other than HPV? What is the cellular pathophysiology in DBA and TEC? Does the apparent heterogeneity of these disorders reflect limitations of laboratory techniques or are we looking at several different diseases? Is acute leukemia a real complication of Diamond-Blackfan anemia? Is TEC a completely benign entity or will we see other long-term problems in these children? Is the incidence of TEC actually increasing? Will TEC-like problems be seen in other aged children? As a case in point, we recently observed a 16-year-old girl who presented with pure RBC aplasia that required RBC transfusion support for 5 months; she also received prednisone therapy. After 7 months, however, this young lady had a spontaneous remission, and now 4 years later she is normal and free of any hematologic abnormalities. This was a most unusual event in our experience and, in view of the apparent increasing incidence of TEC in young children, we queried whether we were observing an adolescent equivalent of this disorder. During the next several years the answer to this and the other questions posed herein should be available.