Hemolytic anemia

 

Pearls

1. Hemolysis due to Ig M cold antibodies which cause agglutination and complement mediated destruction of RBC when temp is less than body temp.

2. Cold agglutinin titer at > 1/64 at 4 degree celsius, C3d+ on DAT

3. Fatigue out of proportion to anemia, peripheral vascular symptoms due to clumping RBC

4.  Treatment options:

- steroids generally ineffective

-Rituxan 50% effective. Can be combined with benda or fludarabine.

- eculizumab not effective in raising Hb

- dara helpful 8 weekly doses; may do maintenance

-sutimlimab C1 inhibitor--> 80% improvement in HB but no effect on peripheral symptoms.

5. Supportive care: avoidance of cold, warm blood product, avoid warming blankets ( can lead to gangrene).

Pearls ASH 2024 Hematology series

 1. CLL patients often have warm AIHA. If neg DAT, could be due to high activity low titer antibody

2. Amlodipine and Keflex can cause drug associated hemolytic anemia

3. Upto 10% of warm AIHA can be DAT neg. If less than 100-500 molecules per RBC can be low titer but high activity.

4. Spherocytes are seen Warm hemolytic anemia, cold hemolytic anemia have agglutination. Raynaud's are seen in Cold AIHA.

5. Spherocytes are seen in : hereditary spherocytosis but not in thalassemia. Spherocytes are also seen in spider and scorpion bites, thermal injury.

Reference: https://www.tandfonline.com/doi/pdf/10.1080/17474086.2024.2366540