Further labwork:
- LDH elevated at 1500, Haptoglobin low at <10
- This led to a suspicion for hemolytic anemia
- Vitamin B12 low at 67 pg/mL
- Unexplained by dietary intake
- Folate within normal limits
- Peripheral smear showed 1+ schistocytes
A direct antiglobulin test returned positive for a warm IgG antibody. This explained, in part, her hemolytic anemia (though a low vitamin B12 level can also cause a hemolytic anemia). However, it did not explain why she would have a low B12 level. HIV, viral hepatitis, CMV, EBV, and an ANA all returned negative.
She required 1 unit of packed red blood cells on day 2 of hospitalization for a hemoglobin < 7.
She was supplemented with IM vitamin B12 and started on prednisone 1mg/kg qday, and within 3 days her reticulocyte count rebounded to 14%.
Anti-parietal and anti-intrinsic factor antibodies were obtained before discharge, and the anti-intrinsic factor returned positive, suggesting an element of pernicious anemia, explaining the low B12 level.
For more, see Anemia