Paroxysmal Nocturnal Hemoglobinuria: A Case Report in a Pandemic Environment

Vanda Peixoto1,2, Ana Carneiro3, Fernanda Trigo3

  • 1Chemical and Biomolecular Sciences, School of Health, Polytechnic Institute of Porto, 4200-072 Porto, Portugal.

Reports (MDPI)
|July 29, 2025
PubMed

Paroxysmal nocturnal hemoglobinuria (PNH) is a clonal, rare, complement-mediated hemolytic anemia. PNH can be associated with marrow failure and thrombophilia. We present a clinical report of splenic vein thrombosis in a patient with classic PNH. A 41-year-old male with classic PNH, naïve to complement inhibitor therapy, developed splenic vein thrombosis as a major adverse effect after vaccination protocol to prevent meningococcal disease. We also report anticoagulant and eculizumab treatment outcomes. In PNH patients, vaccination should be monitored to prevent major outcome events, like vaccine-induced thrombosis. Eculizumab proves effective for treating intravascular hemolysis and preventing more thrombotic events. The potential protective role of eculizumab on controlling complement activity and consequent inflammation may help the patient to not experience breakthrough hemolysis when infected with SARS-CoV-2. Extravascular hemolysis remains present, but new molecules are being studied to inhibit proximal complement and there is a good health prospective for PNH patients.