Cold Agglutination of Erythrocytes in Complete Blood Count

Impact of cold agglutination on CBC parameters: falsely elevated MCHC, spurious erythrocytopenia, and correction by warming to 37 °C.

Юлия Романова 1 min March 5, 2020

Analyzer screen before warming: underestimated RBC (0.27) and critical MCHC (2966 g/L)

Analyzer screen: RBC differentiation and distribution flags at room temperature

Analyzer screen: pathological RBC histogram in cold agglutination

Blood smear before warming: pronounced cold agglutination of erythrocytes

Analyzer screen after warming to 37 °C: normalization of MCHC (331 g/L) and RBC

Analyzer screen: analyzer flags after sample incubation at 37 °C

Analyzer screen: normalization of the RBC histogram curve after warming

Blood smear after warming to 37 °C: disintegration of erythrocyte agglutinates

Cold agglutination of erythrocytes. A 77-year-old female patient. Diagnosis unknown. Reportedly suffers from anemia; the local laboratory cannot perform a CBC because “the blood clots quickly.” Examination revealed: standard coagulogram within normal limits, macrocytic anemia, leukopenia, changes in the leukocyte differential count, and cold agglutination of erythrocytes. Photos 1-4 – CBC at room temperature, photos 5-8 – blood examination after incubation at 37 °C.