In autoimmune hemolytic anemia the immune system makes antibodies against the patient's own red blood cells, which are destroyed faster than the marrow can replace them. The warm type (IgG) is most common and the cold type (IgM) worsens with cold exposure; both can be primary or linked to lymphoma, lupus, infections or drugs.
Key symptoms
- Fatigue, shortness of breath and palpitations
- Yellow skin or eyes
- Dark urine with brisk hemolysis
- Blue, painful fingers or toes in the cold (cold type)
What you find on exam
- Pallor and yellow sclera
- Fast heart rate and a flow murmur
- Enlarged spleen
- Enlarged lymph nodes or signs of lupus that point to a cause
Tests
- Blood count: low hemoglobin, high reticulocytes; spherocytes or clumped cells on the smear
- Hemolysis labs: high LDH and indirect bilirubin, low haptoglobin
- Direct antiglobulin (Coombs) test: positive for IgG, C3 or both
- Search for a cause: lymphoma workup, ANA, HIV, hepatitis and a drug review
Treatment basics
- Warm type: prednisone about 1 mg/kg daily with a slow taper
- Rituximab for relapse or when steroids fail
- Folic acid; stop any causative drug and treat the underlying disease
- Cold type: keep warm; rituximab or sutimlimab; steroids work poorly
- Transfuse for severe anemia, using warmed blood in the cold type
Red flags
- Rapidly falling hemoglobin with chest pain, breathlessness or confusion
- Very dark urine with kidney injury
- Leg swelling or sudden breathlessness, since hemolysis raises clot risk
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.