Leukoerythroblastic Reaction in an Adolescent with Sickle Cell Anemia and Septic Arthritis: A Case Report

Reacción leucoeritroblástica en adolescente con anemia falciforme y artritis séptica: Reporte de Caso

Abstract

The leukoerythroblastic reaction (LER), characterized by the simultaneous presence of erythroblasts and immature granulocytes in peripheral blood, is usually associated with bone marrow infiltration or neoplasms, although it may also occur in reactive conditions such as sepsis, hemolysis, or hypoxia. In sickle cell disease (SCD), its finding is unusual, especially in the pediatric population. We present the case of a 14-year-old girl with homozygous SCD, with a history of multiple transfusions and recurrent crises, who was admitted with fever, septic arthritis, severe anemia (Hb 4.2 g/dL), leukocytosis, and reticulocytosis. The peripheral smear showed LER with orthochromatic erythroblasts, granulocytic left shift, and the typical poikilocytosis of SCD—findings not detected by the automated blood count. Subsequently, she developed a positive direct Coombs test, a decrease in reticulocytes, and transfusion requirements, consistent with hyperhemolysis syndrome. She evolved favorably after antibiotic treatment and joint lavage, with resolution of the LER. This case highlights the importance of Clinical Pathology, emphasizing the value of the peripheral smear as a diagnostic and prognostic tool complementary to automated systems.