Hemolytic anemia characterized by evidence of intravascular hemolysis such as hemoglobinuria and elevation of plasma lactate dehydrogenase.
Diagnosis can be made by flow cytometry of granulocytes and RBCs, looking for the lack of the glycosylphosphatidylinositol anchor or of proteins dependent on it for attachment to the cell membrane.
Complicated by thrombosis, particularly of hepatic and other intra-abdominal veins, cerebral veins, and other usual and unusual venous sites.
Specifically treated with a monoclonal antibody to the fifth component of complement (eculizumab).
May arise in patients with or recovering from aplastic anemia, and it may manifest with cytopenias that are the result of marrow hypoproduction, which may respond to treatment for aplastic anemia.
Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired disorder of the blood characterized by intravascular hemolysis and thrombophilia due to the absence of glycosylphosphatidylinositol-anchored proteins on the membrane surface of blood cells.It is associated with relative or absolute marrow hypoplasia.
History and exam
Key diagnostic factors
- Budd-Chiari syndrome
Other diagnostic factors
- history of aplastic anemia
- abdominal pain
- dysphagia and odynophagia
- erectile dysfunction
- bleeding diathesis
- neurologic signs and symptoms
- aplastic anemia/hypoplastic bone marrow
1st investigations to order
- urine dipstick
- urine microscopy
- reticulocyte count
- serum LDH
- unconjugated bilirubin
Investigations to consider
- flow cytometry for glycosylphosphatidylinositol anchor or anchored proteins
- fluorescent aerolysin
- antiglobulin (Coombs) test
- serum iron, serum ferritin
- serum creatinine and BUN
classic PNH (hemolytic anemia): nonpregnant
classic PNH (hemolytic anemia): pregnant
PNH in the setting of another specific bone marrow disorder: nonpregnant
PNH in the setting of another specific bone marrow disorder: pregnant with thrombosis
PNH in the setting of another specific bone marrow disorder: pregnant without thrombosis
subclinical PNH: nonpregnant
subclinical PNH: pregnant
following acute clinical PNH with thrombosis: nonpregnant
- Autoimmune hemolytic anemia, warm antibody type
- Microangiopathic hemolytic anemia
- Paroxysmal cold hemoglobinuria
- Consensus guidelines to detect GPI‐deficient cells in paroxysmal nocturnal hemoglobinuria (PNH) and related disorders: Part 1 – clinical utility
- The physician's guide to paroxysmal nocturnal hemoglobinuria (PNH)
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