Paroxysmal Nocturnal Hemoglobinuria Differential Diagnoses

Updated: Jun 06, 2023
  • Author: Emmanuel C Besa, MD; Chief Editor: Sara J Grethlein, MD, MBA, FACP  more...
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Diagnostic Considerations

Patients should be tested at least once for paroxysmal nocturnal hemoglobinuria (PNH) if they have any of the following [26] :

  • Evidence of hemoglobinuria
  • Unexplained hemolysis (increased lactate dehydrogenase [LDH] level, absent haptoglobin)
  • Abdominal or cerebral vein thrombosis
  • hrombocytopenia, macrocytosis, or signs of hemolysis

Patients who should be tested repeatedly for PNH (at least every 6 mo or annually) include the following:

A review of 282 Korean patients with PNH by Kim et al identified 24 patients with both PNH and severe aplastic anemia (ie, with at least two of the following three criteria: hemoglobin ≤8 g/dL; absolute neutrophil count (ANC) < 0.5 × 109/L; platelet count < 20 × 109/L). Compared with patients with classic PNH, the patients with PNH and severe aplastic anemia had a significantly lower median granulocyte PNH clone size (26.7 vs. 51.0%, P = 0.021), a lower incidence of lactate dehydrogenase levels ≥1.5 times the upper limit of normal (52.9 vs. 80.0%, P = 0.049), and significantly lower survival. Given those differences, these authors suggest that identifying this subgroup at the time of diagnosis may be important. [27]

Differential Diagnoses