New report highlights benefits of early detection and treatment in PNH
Diagnosis occurred before thrombosis, allowing early start of therapy
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Early recognition of paroxysmal nocturnal hemoglobinuria (PNH) in a 39-year-old woman with unexplained anemia led to treatment starting before any blood clot, or thrombotic, complications were detected, according to a case report from Portugal.
The woman sought emergency care multiple times after several weeks of worsening fatigue and recurrent dark-colored urine. She had initially been treated for iron-deficiency anemia, but her condition did not improve with oral iron supplementation.
Blood tests revealed signs of intravascular hemolysis, meaning red blood cells were being destroyed inside blood vessels, prompting further testing that led to a PNH diagnosis. Treatment with Soliris (eculizumab), an approved therapy for PNH, was started soon after, and her symptoms improved, the researchers reported.
Why early recognition of PNH can change patient outcomes
“This case highlights the importance of maintaining a high index of suspicion for PNH in patients with unexplained hemolysis or recurrent dark urine, as delayed recognition remains common and may increase the risk of severe and potentially life-threatening thrombotic complications,” the researchers wrote, emphasizing that early recognition and timely treatment are essential to improve outcomes.
The study, “Paroxysmal Nocturnal Hemoglobinuria in a Young Adult Woman: A Representative Case of Recurrent Intravascular Hemolysis,” was published in Cureus.
PNH is marked by a deficiency of certain proteins on the surface of blood-forming cells due to a defect in glycosylphosphatidylinositol (GPI), a molecule that normally helps attach these proteins to the cell surface. Without these proteins, blood cells become vulnerable to attack by part of the immune system called the complement cascade.
This can cause intravascular hemolysis, leading to anemia and an increased risk of blood clots. Damage to other blood cells can also cause cytopenia, or low blood cell counts.
Common PNH symptoms include fatigue, shortness of breath, and repeated episodes of dark-colored urine. Dark urine happens when hemoglobin, the oxygen-carrying molecule inside red blood cells, is released into the urine when red blood cells break apart. These episodes are often more noticeable in the morning.
The disease is usually diagnosed using flow cytometry, a specialized lab test that can detect the absence of GPI-anchored proteins on blood cells, helping distinguish PNH from other causes of hemolytic anemia.
Soliris — given by intravenous (into-the-vein) infusion — targets a complement protein called C5 to stop intravascular hemolysis. Early diagnosis and treatment are key to helping reduce the risk of serious complications.
Woman’s unexplained anemia and hemolysis lead to PNH diagnosis
Here, researchers described the case of a woman with unexplained anemia whose signs of intravascular hemolysis led to a PNH diagnosis and targeted treatment before major complications developed.
The previously healthy woman was being followed in an immunohematology clinic after routine blood tests showed iron-deficiency anemia that did not improve with oral iron supplements, leading doctors to start iron infusions.
She later sought medical care after three weeks of worsening fatigue, mild shortness of breath with activity, occasional dizziness, and recurrent episodes of dark-colored urine, particularly in the morning, leading to several visits to the emergency department. On examination, she appeared pale and had mild scleral icterus, or yellowing of the whites of the eyes.
Blood tests showed signs of severe hemolytic anemia, including elevated lactate dehydrogenase, a marker of red blood cell breakdown, and bilirubin, a substance released when red blood cells are destroyed. Mild reductions in certain white blood cells were also observed.
Further testing showed Coombs-negative hemolytic anemia, meaning her red blood cells were not being destroyed by antibodies, helping rule out an immune-mediated hemolytic disease. Imaging scans showed no evidence of blood clots.
Flow cytometry then confirmed the absence of GPI-anchored proteins on many blood cells, confirming the PNH diagnosis.
Vaccination and complement therapy begin after confirmed diagnosis
Before starting Soliris, the woman received recommended vaccinations against Streptococcus pneumoniae and Neisseria meningitidis. This is because treatments that target the complement system, part of the immune system that helps protect against certain serious bacterial infections, may increase infection risk.
Soliris was then given at standard dosing. After three months of treatment, her hemoglobin levels stabilized, her fatigue improved, and episodes of dark-colored urine subsided. She remains on Soliris every two weeks and continues to show improvement, the researchers reported.
“This case highlights the importance of considering PNH in patients with Coombs-negative hemolytic anemia and recurrent dark urine,” the researchers wrote, while adding that “early diagnosis, appropriate vaccination, and close longitudinal monitoring are fundamental components for optimizing long-term management and prognosis in PNH.”
