Paroxysmal nocturnal haemoglobinuria. Experience over a 10 years period

Summary Introduction Paroxysmal nocturnal hemoglobinuria (PNH) is a hemolytic, clonal and acquired disorder of the hematopoietic stem cell with a deficiency of all glycophosphatidyl‐inositol (GPI) linked proteins. The aim of this retrospective study was to analyse haematological and biochemical data from 152 patients referred to our laboratory for diagnosis of PNH by flow cytometry (FC). Methods Patients and healthy donor (152 and 99 respectively) were studied. Ham, sucrose, lactate dehydrogenase (LDH), Iron, haptoglobin (Hp), blood cell morphology and Kaplow cytochemical stain for leukocyte alkaline phosphatase (LAP) were carried out. GPI‐proteins anti‐CD55 and CD59 in erythrocytes and the former, plus anti CD16b and CD66b on neutrophils were evaluated by FC. Results Anemia and/or leukopenia and/or thrombocytopenia, increased reticulocyte count and LDH were observed in patients with PNH clone. Some of them had dacriocytes, schistocytes. LAP was low. On average, we detected 50% CD59 (−) erythrocytes and 29, 83, 78% CD55/59 (−), CD16b (−), CD66b (−) neutrophils, respectively. Conclusion Paroxysmal nocturnal hemoglobinuria clone was detected in 20/152 patients. Negative population's percentages were high in patients with classic PNH, Hematimetry, LAP and adequate use of CF contribute to PNH clone detection in the laboratory.