Cold Agglutinin Syndrome (CAS) is a rare immune-mediated hemolytic anemia in children, typically triggered by infections and characterized by red blood cell agglutination at low temperatures below 37°C due to IgM autoantibodies. Pediatric CAS often presents with anemia, jaundice, and respiratory infections. While well-documented in adults, pediatric CAS remains underreported, with limited data on hemoglobin kinetics. Here we present a case series of four pediatric patients diagnosed with post-infectious Cold Agglutinin Syndrome (CAS), a rare form of autoimmune hemolytic anemia. Three cases were triggered by confirmed Mycoplasma pneumoniae infection, while one had a probable viral etiology. Hemoglobin levels at presentation varied from severe anemia (4.3 g/dL) requiring transfusion to mild reductions (12.8 to 11.5 g/dL). Laboratory findings demonstrated RBC agglutination in three patients, elevated LDH (218–3052 IU/L), and positive cold agglutinin titers in two cases. The direct Coombs test was positive or weakly positive in three cases. Two children required blood transfusions, and all received antimicrobial therapy. Reticulocyte counts ranged from initial reticulocytopenia (0.3%) to compensatory reticulocytosis (2.3%) after treatment. Supportive care, including warmed transfusions and nutritional supplementation, led to full hematological recovery in all cases. This series highlights the transient, infection-associated nature of pediatric CAS and underscores the importance of early diagnosis and conservative management. Thus Pediatric CAS is typically self-limiting and infection-driven. Hemoglobin kinetics and lab markers like LDH and reticulocyte counts guide diagnosis and recovery monitoring. Supportive care and appropriate antibiotics are generally sufficient for management.
Neetha et al. (Sat,) studied this question.