A patient with Paroxysmal Noctural Hemoglobinuria (PNH) may develop a number of signs and symptoms associated with smooth muscle dystonia.


Mechanism: nitric oxide depletion during hemolytic episodes caused by (1) binding with free plasma hemoglobin and (2) release of erythrocyte arginase which reduces nitric oxide synthesis.


Signs and symptoms may include:

(1) abdominal pain

(2) esophageal spasms

(3) erectile dysfunction

(4) fatigue


Risk factors:

(1) percent of granulocytes marking as PNH > 60%

(2) hemolytic episode with hemoglobinuria

(3) low serum haptoglobin levels


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