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Hemolytic Markers P...

Metadata

• Author: @WilliamAird4 on Twitter
• Full Title: 1/8
  Hemolytic Markers P...
• Category: #tweets
• URL: https://twitter.com/WilliamAird4/status/1676289374047051792

Highlights

• 1/8
  HEMOLYTIC MARKERS POST HEMATOMA
  I recently saw a 76 yo M with unremarkable history (HTN), who presented with syncopal episode. He was hypotensive and found to have massive soft tissue hematoma on chest wall (shown in graphic).
  (View Tweet)
• 2/8
  His admission labs showed leukocytosis with left shift, normocytic anemia with nRBCs, and mild thrombocytopenia, all c/w acute bleed (the low platelet count is presumably from consumption in the hematoma). Also, the aPTT was prolonged (PT normal).
  (View Tweet)
• 3/8
  Isolated prolongation of the aPTT is caused by a deficiency of or inhibitor against one or more of the intrinsic factors (FXII, FXI, FIX or FVIII). FVIII levels were found to be 3% and an inhibitor screen was positive. Thus, the patient had acquired hemophilia A. (View Tweet)
• 4/8
  The patient was treated with bypassing agents, immunosuppressive therapy, and multiple units of pRBCs. On day 2, his LDH started to increase as did his total bilirubin (later confirmed to be indirect/unconjugated). His haptoglobin was undetectable.
  What was going on?
  (View Tweet)
• 5/8
  A patient with acquired hemophilia is unlikely to present coincidentally with a new/rare hemolytic disease. e.g., TTP or PNH. There are really only 2 considerations in this case:
  1. Delayed transfusion reaction (DTR)
  2. Resorbing hematoma
     The DAT was neg ruling out DTR.
     (View Tweet)
• 6/8
  This is a really good reminder that in addition to the classic immune vs. non-immune and extracorpuscular vs. intracorpuscular causes of hemolysis we should keep in mind three conditions that may present with positive hemolytic markers through other mechanisms: (View Tweet)
• 7/8
  1. Resorbing hematoma - local tissue macrophages phagocytose extravasated/extravascular RBCs, and process the Hb just as they do in immune hemolytic anemia.
  2. Megaloblastic anemia - destruction of erythroid precursors in the bone marrow causes a hemolytic picture. (View Tweet)
• 8/8
  3. Hemophagocytic lymphohistiocytosis (HLH) - activated macrophages phagocytose RBCs in multiple tissues, breaking down Hb as macrophages do in immune hemolytic anemia or with hematoma resorption. (View Tweet)