Paroxysmal Nocturnal Hemoglobinuria (PNH) – YES, it shows up on Step 1, and you need to know the essentials!
Here’s what you need to remember:
- PIGA gene mutation in hematopoietic stem cells
- Deficiency of CD55 and CD59
- Complement-mediated intravascular hemolysis
- Classic triad: hemolytic anemia, pancytopenia, and venous thrombosis (think Budd-Chiari syndrome)
✅ Diagnosis: Flow cytometry
✅ Treatment: Eculizumab
💡 Exam clue: patient waking up with dark urine in the morning = think PNH!