Paroxysmal Nocturnal Hemoglobinuria (PNH)

Paroxysmal Nocturnal Hemoglobinuria (PNH) is a rare blood disorder that affects the body's red blood cells. It causes these cells to break down too easily, leading to episodes of dark-colored urine, especially in the morning. This happens because the red blood cells are destroyed prematurely, releasing a protein called hemoglobin into the bloodstream. The condition mainly involves the blood and immune system, causing symptoms like fatigue, shortness of breath, and an increased risk of blood clots. PNH can also lead to serious complications such as damage to organs due to clotting. The disease results from a problem in the bone marrow where blood cells are made. Understanding PNH helps explain why patients experience these symptoms and the importance of monitoring blood health.

Paroxysmal Nocturnal Hemoglobinuria (PNH) is an acquired clonal hematopoietic stem cell disorder characterized by a deficiency of glycosylphosphatidylinositol (GPI)-anchored proteins, including the complement regulatory proteins CD55 and CD59. This deficiency results from somatic mutations in the PIGA gene, leading to increased complement-mediated intravascular hemolysis. The hallmark of PNH is chronic hemolytic anemia, often accompanied by hemoglobinuria, especially noticeable in the morning. Patients are also at high risk for thrombosis, which is a major cause of morbidity and mortality. Bone marrow failure and cytopenias may coexist due to overlap with aplastic anemia. Diagnosis and management require understanding the underlying complement dysregulation and its systemic effects.