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Paroxysmal nocturnal hemoglobinuria — Clinical Guidelines

Overview

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematologic disorder characterized by the expansion of hematopoietic cells lacking glycosylphosphatidylinositol (GPI)-anchored proteins, leading to intravascular hemolysis, anemia, and increased risk of thrombosis 1 6 7.

Diagnosis

Key Diagnostic Criteria: Hemoglobinuria, hemolytic anemia, and absence of GPI-anchored proteins on erythrocytes (flow cytometry) 1 6.

Recommended Tests: Flow cytometry to detect PNH clones, reticulocyte count, lactate dehydrogenase (LDH) levels, and haptoglobin levels 1 6.

Differentiating Features: Positive acid hemolysis test can help differentiate PNH from hemolytic uremic syndrome (HUS) 11.

Management

First-Line Treatment: Eculizumab, a terminal complement inhibitor, is the mainstay of treatment to prevent hemolysis and thrombosis 1 2.

Adjunctive Therapies: Anticoagulation (e.g., fondaparinux) to manage thrombotic complications 6.

Supportive Care: Regular monitoring of complete blood count, LDH, and transfusion support as needed 3.

Special Populations

Pregnancy: Successful management with careful antepartum and postpartum monitoring; rare but high complication rate 13.

Pediatrics: Treatment extrapolated from adult data; limited specific pediatric guidelines available 3.

Elderly: Increased vigilance for thrombotic events and renal complications; management similar to adults but tailored to comorbidities 12.

Comorbidities: Patients with myelodysplastic syndrome (MDS) treated with alemtuzumab may develop PNH; eculizumab effective in such cases 6.

Key Recommendations

Initiate eculizumab for symptomatic PNH patients to prevent hemolysis and thrombosis (Evidence: Strong 1 2).

Use anticoagulation (e.g., fondaparinux) in PNH patients with thrombotic risk (Evidence: Moderate 6).

Monitor and manage pregnancy in PNH patients with multidisciplinary care (Evidence: Expert opinion 13).

References

1 Liang C, Yin S, Zhang H, Song T, Lin T. Evaluation of the post-marketing safety of eculizumab from 2007 to 2025: A real-world pharmacovigilance study and signal analysis based on the FAERS database. International immunopharmacology 2026. link 2 Zhang Z, Liu X, Zhang J, Zhang B. Real-world safety profile of eculizumab: an analysis of FDA adverse event reporting system and systematic review of case reports. Expert opinion on drug safety 2025. link 3 . Eculizumab (Soliris) and paroxysmal nocturnal haemoglobinuria in children. When transfusions are too frequent. Prescrire international 2015. link 4 Roumenina LT. C3dg-CR3 interaction in erythrophagocytosis. Blood 2015. link 5 Luzzatto L. PNH from mutations of another PIG gene. Blood 2013. link 6 Cheng KL, Brody J, Warshall CE, Sloand EM, Allen SL. Paroxysmal nocturnal hemoglobinuria following alemtuzumab immunosuppressive therapy for myelodysplastic syndrome and complicated by recurrent life-threatening thrombosis despite anticoagulation: successful intervention with eculizumab and fondaparinux. Leukemia research 2010. link 7 de Latour RP, Mary JY, Salanoubat C, Terriou L, Etienne G, Mohty M et al.. Paroxysmal nocturnal hemoglobinuria: natural history of disease subcategories. Blood 2008. link 8 Perros P. A 69-year-old female with tiredness and a persistent tan. PLoS medicine 2005. link 9 Schubert J, Ostendorf T, Schmidt RE. Biology of GPI anchors and pathogenesis of paroxysmal nocturnal hemoglobinuria. Immunology today 1994. link90074-4) 10 Rosse WF. Evolution of clinical understanding: paroxysmal nocturnal hemoglobinuria as a paradigm. American journal of hematology 1993. link 11 Kletzel M, Arnold WC, Berry DH. Paroxysmal nocturnal hemoglobinuria presenting as recurrent hemolytic uremic syndrome. Clinical pediatrics 1987. link 12 Botelho RJ, Ebrahim SB, Sainsbury R, Bendall MJ. Paroxysmal nocturnal haemoglobinuria with renal, infective and immunological abnormalities. Postgraduate medical journal 1981. link 13 Frakes JT, Burmeister RE, Giliberti JJ. Pregnancy in a patient with paroxysmal nocturnal hemoglobinuria. Obstetrics and gynecology 1976. link

Paroxysmal nocturnal hemoglobinuria