[Natural history of paroxysmal nocturnal hemoglobinuria in adolescents,adults, and children: the Mexican experience]. / Historia natural de la hemoglobinuria paroxística nocturna en adolescentes, adultos y en la edad pediátrica: la experiencia mexicana.

PURPOSE: To compare the clinical patterns and survival of young and adult (AP) versus paediatric (PP) patients with paroxysmal nocturnal haemoglobinuria (PNH). PATIENTS AND METHODS: The clinical records of 117 patients (82% AP, 18% PP) seen in four cities of the Mexican Republic were analysed, the clinical course and survival of both groups being compared. RESULTS: No sex difference was found in the two patient-groups: 51% and 52% males, 49% and 48% females in AP and PP, respectively. The onset of PNH had similar distribution for the two groups of patients: aplastic form, 45% in AP and 62% in PP; cytopenias, 24% in AP versus 27% in PP; haemolysis, 28% in AP and 9% in PP, and thrombosis, 3% in AP versus 0% in PP. The clinical features with significant difference were: anaemic+haemorrhagic syndrome (39 AP (40%) vs 14 PP (67%), p = 0.02), initial diagnosis of immunologic thrombocytopenic purpura (7 AP (7%) vs 7 PP (33%), p = 0.003), and death rate (17 AP (18%) vs 8 PP (38%), p = 0.04). The actuarial survival curves showed significant differences between both groups (p = 0.045, Cox-Mantel), with estimated 10-year survival of 81% for AP and 55% for PP, and 15-year survivals of 64% for AP and 55% for PP. CONCLUSIONS: Seemingly, PNH in paediatric age has poorer prognosis than in adults, which is associated to higher incidence of fatal haemorrhages due to thrombocytopenia.