Thread by @KirtanPatolia

Differential dx of deranged PT/INR/aPTT: More than what meets the eye✨

Based on what I have learned from my colleagues

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@rabihmgeha @DxRxEdu @DrCindyCooper @AaronGoodman33 @CPSolvers @sargsyanz @AnnKumfer @ASanchez_PS @MatthewHoMD @nihardesai7 #hematology

1.) Isolated Elevation of PT/INR

- Deficiency of or inhibitors against Factors lII, VII
- Early Vitamin K deficiency
- Warfarin (PT/INR>aPTT)

#hematology

2.) Isolated elevation of aPTT

- Deficiency of or inhibitors against Factors XII (asymptomatic), XI, IX, VIII.

- Heparin (aPTT>PT/INR)
- vWD type 2N & Acq vWD

- Antiphospholipid antibodies (further evaluation will dRVVT and phospholipid-based mixing studies)

#hematology

3.) Elevation of PT/INR and aPTT

- DIC & Liver failure (low factor VIII in DIC vs NL in the latter)

- Warfarin and heparin

- Severe Vitamin K deficiency

- DOACs

#hematology

4.) Unique and elegant causes ⭐

- aPTT elevation in Mastocytosis (endogenous Heaprin excess)

- PT/INR/aPTT elevation in Amyloidosis due to Factor X sequestration by fibrils (similarly fibrils can trap beta blockers and CCBs in the heart worsening the block)

#hematology

5.) Rare causes ✨✨

- Factor V trapping by myeloid cells in MPNs

- Acquired vWD (hypothyroidism, MM, MPNs, Valvular stenosis, Heyde syndrome)

- Cefoxitin, Cefotetan, Cefoperazone (hypoprothrombinemia and low vitamin K levels by indirectly altering gut flora)

#hematology

6.) Fascinating causes of DIC/DIC-like states 💫💫

- Fat/amniotic fluid embolism
- Acute fatty liver of pregnancy
- APML
- HLH
- Kasabach Merritt syndrome
- Purpura fulminans (Protein C/S/ATIII def, Meningococci, Rickettsia)
- Trousseau
- Snakes
- catastrophic APLA

#hematology

Thanks for reading!!

Any suggestions are appreciated!!

#hematology

@BrownHospMed