1/10

Many Labs Can Be Ab...

Metadata

• Author: @tony_breu on Twitter
• Full Title: 1/10
  Many Labs Can Be Ab...
• Category: #tweets
• URL: https://twitter.com/tony_breu/status/1602051559323484163

Highlights

• 1/10
  Many labs can be abnormally high OR low.
  Others appear to have just one direction of abnormality. But some diagnoses may be suggested by the "reverse abnormality." For example, a...
  ↓aPTT
  ↓Alk phos
  ↓ALT
  ↑B12
  ↓HDL
  ...may mean something.
  Let's have a look. (View Tweet)
• 2/
  ⚡️Low aPTT⚡️
  If a high aPTT raises the concern for a coagulopathy, does that mean a low aPTT should raise the concern for thrombosis?
  Maybe.
  Multiple studies have shown an INCREASED risk of venous thromboembolism with low aPTT.
  It may be a clue!
  https://t.co/nLFLtLnytE
  (View Tweet)
• 3/
  ⚡️Low alkaline phosphatase (ALP)⚡️
  One study looked at 69,864 ALP levels. Just 0.2% (88) were very low (<30 U/L).
  The most common etiology was cardiac surgery and cardiopulmonary bypass. The mechanism of this association isn't clear.
  https://t.co/QD1ySBpjOG
  (View Tweet)
• 4/
  Other rare diagnoses are associated with low ALP.
  One is hypophosphatasia. Consider this diagnosis in those with repeatedly low ALP, particularly if they have a history of fracture.
  https://t.co/c4RyAkELV0
  (View Tweet)
• 5/
  Another rare diagnosis that can present with sporadically low ALP is Wilson's disease. I cover this in a separate thread.
  https://t.co/IB517ovF82 (View Tweet)
• 6/
  ⚡️Low alanine aminotransferase (ALT)⚡️
  I have previously covered the connection between vitamin B6 and ALT. More specifically, low B6 levels can lead to low ALT. This is seen in patients with alcoholic hepatitis.
  https://t.co/JhdwEK4ttD (View Tweet)
• 7/
  Because B6 is a water-soluble vitamin, there is some evidence that patients receiving hemodialysis are at increased risk of deficiency.
  Result: the use of hemodialysis is also associated with lower ALT.
  https://t.co/hTYaP26gOj (View Tweet)
• 8/
  ⚡️Low HDL⚡️
  It's not uncommon to see a low HDL. But the presence of newly low HDL should raise the concern for a paraprotein.
  Particularly when the HDL is undetectable!
  https://t.co/v4tQ3RnTOZ
  (View Tweet)
• 9/
  ⚡️High vitamin B12⚡️
  High B12 is associated with myeloproliferative disorders (e.g., CML, PV, ET).
  I explain the mechanism in a separate thread. Have a look.
  https://t.co/z3lTTr2QQn (View Tweet)
• 10/10
  There are surely other causes of the often unobserved findings outlined above.
  What are other examples of "reverse abnormalities" you use as clues? (View Tweet)