ABSTRACT
INTRODUCTION: Autoimmune hematological complications related to COVID-19 are rare. There are only 5 pediatric case reports of autoimmune hemolytic anemia (AIHA) among 14 million pediatric COVID-19 cases in USA. Four were older (13-17 years), two had underlying autoimmune/hematologic conditions. Immunologic analysis varied, with cold, warm & mixed hemolytic anemias described. We present a previously healthy child with COVID-19 associated severe AIHA with peripheral reticulocytopenia. DESCRIPTION: A 3-year-old male presented with lethargy, fever, tachycardia and jaundice 10 days after COVID-19 diagnosis. Pertinent labs include hemoglobin (Hgb) 3.8 g/dL, Hct 9.9%, bilirubin 3.6 mg/dL, platelets 321,000/muL, RBC count 1.2 M/muL, WBC 35,600/muL, MCV 82.5fL. Reticulocyte count (RC) was only 2.8%. Peripheral blood smear showed anisocytosis, poikilocytosis, nucleated RBCs and left shifted granulocytosis. Bone marrow biopsy revealed erythroid hyperplasia without underlying malignancy;myeloid:erythroid ratio of 0.3:1. The outside hospital reported cold C3 agglutination following 4degreeC incubation, while our laboratory identified spontaneous agglutination at room temperature (warm agglutination). IV fluids, O2, and methylprednisolone (4 mg/kg/day) were started and two packed RBC transfusions (total 30 ml/kg) given for symptomatic anemia with Hgb < 4 g/dL. LDH peaked at 2255 U/L on Day 3. Reticulocyte count was low (2.8%-3.8%) Days 1-3, increased to 6.5% on Day 4 and peaked at >30.0% on Day 7. He was changed to oral prednisone 2 mg/kg/day on Day 12 and discharged on Day 13 with Hgb 7.0 g/dL and RC 29.9%. Most recent Hgb is 13.0 g/dL and RC 2.6%. DISCUSSION: COVID-19 associated AIHA is rare, and previously reported mostly in older children. Our patient was previously healthy, and demonstrated a strong bone marrow response with erythroid hyperplasia. Peripheral reticulocytosis was delayed, and correlated with initiation of systemic steroid therapy. Our patient had both cold and warm agglutination supporting extensive autoimmune destruction of early red cell lineage. These findings support immune activation during acute COVID-19 infection and COVID-19 as a trigger for AIHA. Patients developing AIHA may need to be tested for COVID-19 and carefully monitored for complications.