Transient Erythroblastopenia of Childhood

Transient erythroblastopenia of childhood (TEC) is the most common acquired red cell aplasia occurring in children. It is more prevalent than congenital hypoplastic (Diamond-Blackfan) anemia. This syndrome of severe, transient hypoplastic anemia occurs mainly in previously healthy children between 6 mo and 3 yr of age, and most of the children are older than 12 mo at onset. Only 10% of affected patients are >3 yr of age. The annual incidence is estimated to be up to 4.3 cases per 100,000 children, although it is likely higher, because many cases might go undiagnosed and resolve spontaneously. The suppression of erythropoiesis has been linked to immunoglobulin (Ig)G, IgM, and cell-mediated mechanisms. Familial cases have been reported, suggesting a hereditary component. TEC often follows a viral illness, although no specific virus has been implicated consistently. A study of acute cases found no proof that human herpesvirus (HHV)-6, parvovirus B19, Epstein-Barr virus (EBV), or cytomegalovirus (CMV) is a causative agent.

The temporary suppression of erythropoiesis results in reticulocytopenia and moderate to severe normocytic anemia. Some degree of neutropenia occurs in up to 20% of cases. Platelet numbers are normal or elevated. Similar to the situation observed in iron-deficiency anemia and other red blood cell (RBC) hypoplasias, thrombocytosis is presumably caused by increased erythropoietin, which has some homology with thrombopoietin. Mean corpuscular volume (MCV) is characteristically normal for age, and fetal hemoglobin (HbF) levels are normal before the recovery phase. RBC adenosine deaminase (ADA) levels are normal in this disorder, thus contrasting with the elevation noted in most cases of congenital hypoplastic anemia (Table 444-1). Differentiation from the latter disease is sometimes difficult, but differences in age at onset and in age-related MCV, HbF, and ADA are usually helpful. The peak occurrence of TEC coincides with that of iron-deficiency anemia in infants receiving milk as their main caloric source; differences in MCV should help to distinguish between these 2 disorders.

Table 444-1 COMPARISON OF DIAMOND-BLACKFAN ANEMIA AND TRANSIENT ERYTHROBLASTOPENIA OF CHILDHOOD