The International PNH Interest group (I-PIG) and the International Clinical Cytometry Society (ICCS) have advised the following should warrant testing for PNH:
- Patients with unexplained haemoglobinuria
- Patients with unexplained Coombs-negative intravascular haemolysis (high serum LDH), especially if associated with concurrent iron deficiency
- Patients with unexplained haemolysis
- Patients with unexplained thrombosis occurring at unusual sites such as Budd-Chiari syndrome, other intra-abdominal sites, cerebral veins and dermal veins, or with evidence of haemolysis, or with associated cytopenias
- Patients with MDS (refractory anaemia or hypoplastic MDS or any subtype with features of haemolysis)
- Patients with Aplastic Anaemia
- Patients with persistent unexplained cytopenias