(842) Parvovirus and New-Onset Systemic Lupus Erythematosus (SLE): A Catastrophic Combination

Introduction: Hemolytic anemia is rare in pediatrics and has a broad differential, including internal RBC abnormalities and external causes like mechanical, immune-mediated, and infectious factors. The work-up is extensive, and severity varies. Here, we discuss the diagnostic work-up and treatment of severe, refractory mixed autoimmune hemolytic anemia (AIHA), a rare and life-threatening subtype.

Description: A healthy 11-year-old presented to a referring hospital’s emergency room after a syncopal event with headache and dysmenorrhea. Initial blood work showed hemolytic anemia and thrombocytopenia with a low reticulocyte count. The direct antiglobulin test was positive for IgG and C3. Basic infectious studies were negative. Head CT was normal, but abdominal CT showed "hypodensities in the spleen, suspicious for infarcts". Further antibody testing indicated mixed AIHA with warm and cold autoantibodies. The anti-nuclear antibody screen was high-titer positive with high-titer triple positive antiphospholipid antibodies. Other serologies showed borderline anti-dsDNA, high-titer anti-RO, and hypocomplementemia, confirming an antiphospholipid syndrome (APS) - SLE overlap diagnosis. A quantitative Parvovirus B19 panel was positive, indicating a likely trigger. A lumbar puncture revealed high opening pressure, and an ophthalmology exam showed bilateral papilledema. Bone marrow biopsy was reassuring.

The patient presented in hypovolemic shock and received high-dose steroids and emergency packed red blood cells, but severe hemolysis persisted. On hospital day 3, left upper extremity weakness developed, and MRI showed "diffuse multifocal small infarcts." Management escalated to IVIG, Rituximab, and Epogen. Due to two infarction locations, there was concern for catastrophic antiphospholipid syndrome (CAPS), and heparin was started. Significant leukocytosis from steroid treatment and APS-related inflammation necessitated plasma exchange to prevent new thromboses. The patient was discharged on lifelong anticoagulation and immunosuppression.

Discussion: Pediatric CAPS is rare and has a mortality rate of 33-50%. Our case provides awareness. This diagnosis should be suspected when hemolytic anemia and thromboses are seen. Anticoagulation initiation is of utmost importance to prevent morbidity and mortality.