Autoimmune hemolytic anemia (AIHA), one type of which is cold agglutinin disease (CAD), is usually considered a benign hematological disease. However, it is associated with high mortality in the intensive care unit (ICU) regardless of age and treatment, according to a recently published study in the American Journal of Hematology.

According to several studies, AIHA has a mortality rate of 8% to 20%. In patients admitted to the ICU, the mortality rate can reach 30%. However, there is a lack of information regarding the factors associated with mortality in the ICU in patients with AIHA.

The authors of this study aimed to assess the factors associated with the need for ICU admission in patients with AIHA and investigate factors associated with mortality after ICU admission through a multicenter observational study including 62 patients with severe AIHA admitted to the ICU between 2013 and 2020.

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The characteristics of patients who died in the ICU were compared with those of patients who survived using Fisher’s exact test for categorical variables and Student’s t-test or the Mann–Whitney U test for quantitative variables. The study also compared the characteristics of patients with AIHA who did not require admission to the ICU with the characteristics of patients who did. 

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Of the included patients, 13% died in the ICU. The 2 causes of death were massive pulmonary embolism and hypoxic cardiac arrest. The 2 most common complications were thrombotic events (despite prophylaxis with enoxaparin) and infection, with incidences of approximately 60% and 40%, respectively.

The factors associated with a higher risk of death were high C-reactive protein level, high leucocyte count, and the need for a blood transfusion. High scores on the Sequential Organ Failure Assessment (SOFA) and Simplified Acute Physiology Score (SAPS) were also considered risk factors. 

After comparing patients admitted to the ICU with those who were not, the authors concluded that the most significant risk factors for ICU admission were a hemoglobin level below 6 g/dL and a high indirect bilirubin level.

“In conclusion, AIHA in adulthood can be life-threatening regardless of age, with a short-term mortality rate in the ICU of 13% in our study whatever the treatment administered,” the authors wrote.


Pouchelon C, Lafont C, Lafarge A, et al. Characteristics and outcome of adults with severe autoimmune hemolytic anemia admitted to the intensive care unit: results from a large French observational study. Am J Hematol. Published online July 24, 2022. doi:10.1002/ajh.26665