Paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria

Updated: 07/14/2024

© Jun Wang, MD, PhD

 

General features

  • Clonal hematopoietic stem cell (HSC) disorder
  • Usually starts in early adults
  • Clinical triad of hemolytic anemia, pancytopenia, and thrombosis
  • Bone marrow failure may occur

Pathogenesis

  • Acquired mutation of PIGA (phosphatidylinositol N-acetylglucosaminyltransferase subunit A)



Clinical features

  • Dark urine at night with partial clearing during the day
  • Hemolysis at night triggered by acidosis during sleep
  • Anemia-related findings: fatigue, pain, organ dysfunction
  • May have aplastic anemia and myelodysplastic syndrome
  • Hemoglobinemia may cause renal insufficiency and pulmonary hypertension
  • Thrombosis: leading cause of mortality, affecting various sites: mesenteric, cerebral or dermal vessels.
  • Smooth muscle dystonias

o   Depletion of nitric oxide (NO) by free hemoglobin

o   Increased smooth muscle tone causing headache, dysphagia, abdominal pain, or erectile dysfunction

Laboratory findings

  • Features of normocytic anemia, with low reticulocyte count
  • Features of hemolysis
  • Leukopenia and thrombocytopenia
  • Elevated BUN and creatinine
  • Negative direct antiglobulin test

Diagnosis

  • Identification of granulocytes and RBCs lacking glycosylphosphatidylinositol (GPI)-linked proteins (CD55, CD59) in appropriate clinical setting

Management

  • Supportive, hematopoietic stem cell transplantation and complement inhibition
  • Prognosis depending on the severity of symptoms and the presence of complications

 

 

Back to anemia

Back to contents

 

Comments

Post a Comment

Popular posts from this blog

Contents

Pathology notes Jun Wang, MD, PhD 1. General information Frequently discussed syndromes Terms of dermatology Terms of hematology 2. Primary immunodeficiency disorders 3. Hemodynamic abnormalities Shock Thrombosis and embolism Bleeding disorders 4.  Benign blood cell disorders Anemia Benign white cell disorders 5. Hematopoietic neoplasms Lymphoid neoplasms Myeloid neoplasms Histiocytic neoplasms: Langerhans cell histiocytosis 6. Cardiovascular system Pulmonary hypertension Cardiovascular system tumors 7. Respiratory tract tumors 8. Gastrointestinal tract Congenital disorders Infectious gastroenteritis Oral cavity Esophagus Stomach Intestinal tumors Salivary glands Exocrine pancreas and gallbladder 9. Urinary system Kidney masses Lower urinary tract 10. Male reproductive system 11. Female genital tract 12. Breast 13. Endocrine organs Pituitary gland Adrenal gland Thyroid gland Parathyroid gland Endocrine pancreas M
Read more

Anemia

Anemia Updated: 07/13/2024 © Jun Wang, MD, PhD   General features Decrease in red cell mass Hemoglobin: Levels of hemoglobin in a specific volume of whole blood Hematocrit: Fraction of whole blood composed of red blood cells Red cell count: Quantity of red cell in a specific volume of whole blood Three major groups based on RBC sizes Microcytic Normocytic Macrocytic Three major causes Blood loss: acute or chronic Increased red cell destruction: hemolysis Reduced production: marrow failure due to genetic abnormality or nutritional deficiency Etiology Genetic abnormality Hemoglobinopathies RBC cytoskeletal abomorlities Enzyme abnormalities Fanconi anemia Nutritional deficiencies: iron, VB12, folate, general malnutrition Physical etiologies: trauma, burns, frostbite, prosthetic valves, etc Chronic diseases: chronic infections, neoplasia, autoimmune disorders, kidney or liver diseases, etc Infectious diseases: hepatitis, sepsis , malaria, etc
Read more

Practice questions Anemia I

Image
Practice questions Anemia I © Jun Wang, MD, PhD   Abbreviations: Hb: hemoglobin HCT: hematocrit MCV: Mean Corpuscular Volume MCHC: Mean Corpuscular Hemoglobin RDW: Red Cell Distribution Width TIBC: total iron binding capacity   1. Use this case for the next three questions . A 25-year-old woman is brought to the emergency department 2 hours after being involved in a motor vehicle accident. She is conscious but feels dizziness and weakness.   Her blood pressure is 90/60 mmHg, and her heart rate is 120 beats per minute. Physical examination reveals pale skin and mucosa and a 15 cm laceration on her left thigh with significant bleeding. What are most likely the CBC and TIBC results? A. Low Hb, low HCT, high MCV, high RDW, high TIBC B. Low Hb, low HCT, slightly low MCV, normal RDW, normal TIBC C. Low Hb, low HCT, slightly high MCV, normal RDW, normal TIBC D. Normal Hb, normal HCT, normal MCV, normal
Read more