Aplastic crisis due to human parvovirus B19 infection in hereditary hemolytic anaemia

Area of Science:

• Pediatric Hematology
• Viral Infections
• Immunology

Background:

• Transient aplastic crisis (TAC) is a temporary cessation of erythropoiesis, often triggered by viral infections.
• Parvovirus B19 is a known cause of TAC, particularly in individuals with chronic hemolytic anemias.
• The diagnostic utility of specific IgM antibodies against parvovirus B19 in TAC requires further elucidation.

Observation:

• Three pediatric cases of transient aplastic crisis were investigated.
• Case 1: A 2-year-old boy with sickle-cell anemia in Rio de Janeiro experienced aplastic crisis in August 1990.
• Cases 2 & 3: Two siblings with hereditary spherocytosis in Santa Maria, RS, developed aplastic crisis in May 1991. Specific anti-B19 IgM was detected in these two siblings.
• Case 4: A third child from the same family who had a prior aplastic crisis did not show detectable IgM anti-B19 antibodies.

Findings:

• Specific immunoglobulin M (IgM) antibodies against parvovirus B19 were identified in the sera of children experiencing transient aplastic crisis.
• The presence of anti-B19 IgM correlated with the acute phase of aplastic crisis in two siblings with hereditary spherocytosis.
• Absence of detectable IgM anti-B19 in one child with a history of aplastic crisis suggests a possible different etiology or a past infection.

Implications:

• The detection of specific anti-B19 IgM antibodies can aid in diagnosing parvovirus B19 as the causative agent of transient aplastic crisis.
• This diagnostic marker is particularly relevant in pediatric patients with underlying hematological conditions like sickle-cell anemia and hereditary spherocytosis.
• Further research is warranted to understand the serological patterns of parvovirus B19 infection in TAC and its impact on different pediatric hematological disorders.