Vitamin B12 Deficiency Masquerading as TTP: Daniela Hermelin’s Life-Saving Diagnostic Reminder
Daniela Hermelin, Chief Medical Officer of ImpactLife Blood Center, posted on LinkedIn:
”Pseudo TTP. I see this phenomenon about once a year, and you don’t want to miss it.
23-year-old female presents with a month of lethargy and a change in mental status. ED Labs show a striking anemia, Hb = 4.5 g/dL and low platelets of 60K. She also has evidence of a microangiopathic hemolytic anemia (MAHA).
Boy, that’s a mouthful. To break that down, she has evidence of hemolysis (red cell destruction – absent haptoglobin, elevated LDH, and increased indirect bilirubin). And this red cell destruction occurs through a shearing process, the red cells are being shredded.
How? MAHAs can occur when small microthrombi form in the microvasculature and red cells are sheared as they pass through the circulation. Under the microscope, we would find sheared red blood cells called schistocytes.
Now that sounds a lot like thrombotic thrombocytopenia purpura, otherwise known as TTP. But in this case, it’s not due to deficiency in ADAMTS13, but it is caused by SEVERE Vitamin B12 deficiency. And in every case, I have ever seen, it is in the setting of pernicious anemia. Anti-intrinsic factor antibodies will be positive.
How can you tell the difference between Pseudo and REAL TTP, and avoid performing therapeutic plasma exchange when it is not necessary?
Big clues and little clues.
Big clue – measure Vitamin B12.
Little clue – review the peripheral smear. It will show evidence of a megaloblastic anemia, HYPERSEGMENTED neutrophils, and bone marrow dysfunction with tear-drop cells (dacrocytes). These are not findings in TTP.
Check out this article: When the diagnosis is difficult to digest: severe vitamin B12 deficiency secondary to pernicious anemia mimicking life-threatening thrombotic thrombocytopenic purpura
to learn more about this disease and keep it on your differential.”
Title: When the diagnosis is difficult to digest: severe vitamin B12 deficiency secondary to pernicious anemia mimicking life-threatening thrombotic thrombocytopenic purpura
Authors: Matthew Sochat, Daniela Hermelin, Daniel Chakos, Azam Farooqui, Jason Lunt, Ara Vartanyan, Nishant Poddar

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