Thanks to Becky for presenting the case of a middle-aged woman with h/o SLE and Evans syndrome who presenting with subacute onset of fatigue after her prednisone dose was reduced, found to have iatrogenic adrenal insufficiency, lupus flare, and mixed autoimmune hemolytic anemia!
Clinical Pearls:
- Evans syndrome describes AIHA + ITP, a rare condition associated with SLE and often precedes the diagnosis of SLE by a few years.
- Hematologic manifestations of SLE are many and include the following
- Anemia (chronic disease, iron deficiency, medication-induced, warm AIHA>>cold AIHA, pure red cell aplasia, MAHA, and pernicious anemia)
- Leukopenia
- Thrombocytopenia
- Pancytopenia
- Evans syndrome
- Smear findings can be very helpful in diagnosing different types of hemolytic anemias. Schistocytes are a very specific for MAHA, valve disorders, AVMs, APLS whereas AIHA would result in spherocytes.
- The negative predictive value of spherocytes is low. So a smear without spherocytes does not rule out AIHA!
- Lastly, the most common cause of adrenal insufficiency (AI) is iatrogenic.
- General rule of thumb for when risk of AI is high and you should taper steroids slowly is if someone is on prednisone > 20 mg for > 3 weeks. Keep in mind that people with smaller BSA would be more susceptible to AI and at risk with even lower doses.
Hemolytic anemia work up
Check smear
- Schistocytes
- MAHA: TTP, HUS, HELLP, DIC, HTN
- Valve disorder
- AVMs
- APLS
- No schistocytes (+ spherocytes)
- Intrinsic RBC defect
- Enzyme deficiency (G6PD)
- Hemoglobinopathy (sickle cell)
- Membrane defect (hereditary spherocytosis)
- Extrinsic RBC defect
- Liver disease
- Splenic sequestration
- Infections (clostridium perfringens, babesia, malaria, bartonella)
- Meds/toxins (dapsone, nitrites, lead, copper, snake venom)
- AIHA (warm and cold)
- Intravascular
- Transfusion reaction
- Infections
- PNH
- Intrinsic RBC defect
Lab findings in AIHA:
- ↑ retic
- ↑ indirect bili
- ↑ LDH
- ↓ haptoglobin
- + DAT (but keep in mind that DAT can be negative in 3% of patients with WAIHA)
- + spherocytes
Summary of AIHAs: