Investigating the Impact of Cold Agglutinins on Red Blood Cell Parameters in a Trauma Patient.

Cold agglutinins are autoantibodies that can cause primary hemolytic anemia and RBC agglutination syndrome. Secondary agglutination of RBCs may be found in hypothermia, as well as in cancers, infections, and traumatic injuries. This report presents the case of a 37-year-old man who suffered multiple injuries in a motorcycle accident. On admission, the patient's laboratory tests showed a high concentration of cold agglutinins associated with low RBC count, hemoglobin, and hematocrit, and elevated mean corpuscular hemoglobin and mean corpuscular volume. Intravenous immunoglobulin treatment was effective at reversing the abnormal blood parameters to normal. Unlike acute blood loss, which typically manifests with normal hemoglobin and hematocrit levels initially due to proportional loss of plasma and red cells, the presence of cold agglutinins can lead to abnormal agglutination and sequestration of RBCs, with low hemoglobin and hematocrit. The findings of this case report highlight the importance of recognizing cold agglutinins in trauma patients to avoid misdiagnosis and misinterpretation of laboratory results.