DESCRIPTION

• Transient erythroblastopenia of childhood (TEC) is a self-limited, acquired anemia in an otherwise healthy child due to a transient suppression of red cell precursors in the bone marrow. It is the most common cause of pure red cell aplasia (PRCA) in childhood.
• Anemia in TEC is typically normocytic with a normal mean red blood cell (RBC) volume (MCV) and an inappropriately low reticulocyte count in response to often a very low hemoglobin level.
• TEC should be differentiated from Diamond-Blackfan anemia (DBA) that is another red cell aplasia accompanied by reticulocytopenia occurring in young children. However, red cell aplasia in DBA is often caused by genetic mutations and is lifelong with a prognosis that is very different from TEC.

EPIDEMIOLOGY

• Occurs in young children typically 1 to 4 years of age but can occur in infants and children aged >4 years (age range: 1 month to 6 years)
• Slight male predominance has been reported.
• Occurs in all ethnic groups
• No true seasonal predominance, although occasional clustering of cases has been noted
• The exact incidence of TEC remains unknown. This is likely due to underreporting of asymptomatic cases that resolve spontaneously and do not come to medical attention. Estimated incidence varies from 4.3 to 20 cases per 100,000 children.

ETIOLOGY

• Unknown
• A viral illness may precede the diagnosis of TEC in about 50% cases occurring 2 to 3 months before the diagnosis. Implicated viruses include parvovirus B19, human herpesvirus 6 (HHV-6), and echovirus. However, the role played by these viral infections in causing TEC is not understood.
• Serum inhibitors such as an IgG directed at the committed erythroid stem cell progenitor as well as cell mediated suppression of erythropoiesis have been proposed.

RISK FACTORS

TEC has been reported to occur, albeit rarely, in twin pairs and siblings either concurrently but sometimes years apart, suggesting a combination of environmental factors and perhaps a genetic propensity to yet unknown triggers.

GENERAL PREVENTION

There is no known way to prevent TEC.

PATHOPHYSIOLOGY

TEC occurs due to the paucity of red cell precursors in the bone marrow. If bone marrow testing is performed, although it is not required to make a diagnosis, the marrow is normal except for a paucity or absence of red cell marrow precursors.