Paroxysmal Nocturnal Hemoglobinuria: Symptoms, Causes, Treatment
البيلة الهيموغلوبينية الليلية الانتيابية
Paroxysmal nocturnal hemoglobinuria is a rare blood disorder that can cause red-cell breakdown, anemia and clots. It does not occur only at night, and dark urine is not always present.
What is Paroxysmal Nocturnal Hemoglobinuria?
It usually arises from an acquired change in a blood-forming cell, leaving some descendants without complement-protective proteins. It is generally not passed from parents to children.
Related reading: Aplastic anemia and marrow failure.
Symptoms
Fatigue, pallor, breathlessness, dark urine, abdominal pain or swallowing difficulty may occur. Clots can affect unusual sites, and platelet or white-cell counts may also fall.
Causes
An acquired variant, commonly involving PIGA, makes affected cells vulnerable to destruction. The condition may coexist with marrow failure such as aplastic anemia and is not caused by a particular food.
Risk factors
The disorder may be detected during investigation of marrow failure or unexplained hemolysis. Urine color alone is insufficient, and a small PNH clone does not automatically require the same treatment as active disease.
Diagnosis
Flow cytometry detects cells missing protective surface proteins. Blood counts, hemolysis markers and kidney tests assess impact; selected cases need marrow evaluation.
Treatment
Treatment depends on hemolysis, clots and marrow failure. Options include complement inhibitors and supportive care, while stem-cell transplantation is considered for selected situations.
Complications
Complications include thrombosis, kidney injury and severe anemia. Follow-up assesses response, treatment effects and recurrent hemolysis, with risks varying between individuals.
Prevention
Complement-inhibitor treatment requires a vaccination and infection-safety plan, sometimes with preventive medication. Vaccines do not remove all risk. Do not interrupt treatment without supervision.
When to see a doctor
Fever during complement inhibition requires urgent advice. Chest pain, sudden breathlessness, severe headache, acute abdominal pain or a swollen leg warrants emergency assessment.