Red blood cell agglutination caused by ceftriaxone and its effect on erythrocyte parameters: a case report

Ceftriaxone, a widely used antibiotic, is one of the most common drugs to cause drug-induced immune hemolytic anemia. In this report, we describe the effect of ceftriaxone on red blood cell parameters (low red blood cell count, low hematocrit, and high erythrocyte index values) in two pediatric patients without clinical symptoms of hemolytic anemia. Although automated hematology analyzers have helped to detect incorrect results, a peripheral blood smear examination was necessary for recognizing the erythrocyte agglutinins caused by ceftriaxone. Serological testing was not possible, but the resulting drug-induced antibodies mimicked cold agglutinins in the first patient and warm agglutinins in the second patient. Timely reactions and corresponding laboratory procedures prevented potential complications due to drug administration. This report aims to present laboratory findings and preanalytical challenges in these cases and share our experiences in solving them.