RESUMO
BACKGROUND: Thrombotic events are well documented in primary erythrocytosis, but it is uncertain if secondary etiologies increase the risk of thrombosis. This study aimed to determine the causes of erythrocytosis and to identify its impact as a risk factor for thrombosis. METHODS: Data were obtained from patients with erythrocytosis between 2000 and 2017 at a referral hospital in Mexico City. Erythrocytosis was defined according to the 2016 WHO classification. Time to thrombosis, major bleeding, or death were compared among groups of patients defined by the etiology of erythrocytosis using a Cox regression model, adjusting for cardiovascular risk factors. RESULTS: In total, 330 patients with erythrocytosis were studied. The main etiologies of erythrocytosis were obstructive sleep apnea (OSA) in 29%, polycythemia vera (PV) in 18%, and chronic lung disease (CLD) in 9.4% of the patients. The incidence rate of thrombosis was significantly higher in patients with PV and CLD than that in patients with OSA (incidence rates of 4.51 and 6.24 vs. 1.46 cases per 100 person-years, P=0.009), as well as the mortality rate (mortality rates of 2.72 and 2.43 vs. 0.17 cases per 100 person-years, P =0.003). CONCLUSION: The risk of thrombosis in CLD with erythrocytosis was comparable to that in patients with PV. Further larger-scale studies are needed to confirm these findings and evaluate the benefits of preventive management of COPD with erythrocytosis similar to PV.
RESUMO
La policitemia primaria es producida por una mutación adquirida o heredada en las células progenitoras de los glóbulos rojos, mientras que la poliglobulia secundaria está relacionada con un aumento de la eritropoyetina sérica como respuesta a la hipoxia tisular o a la producción autónoma tumoral. Hace más de medio siglo que se conoce que la hidronefrosis puede actuar como una rara causa de eritrocitosis debido al aumento de producción de eritropoyetina por un riñón que censa una disminución de oxígeno, mecanismo también observado en la estenosis de la arteria renal y en los quistes renales. Se describe a continuación el caso de un paciente de 38 años con poliglobulia atendido en el Hospital Italiano de San Justo (Argentina), que presenta como hallazgo una hidronefrosis unilateral severa y cuya resolución quirúrgica a través de una nefrectomía revierte el cuadro hematológico de base. (AU)
Primary polycythemia is produced by an acquired or inherited mutation in progenitor cells of red blood cells, while secondary polyglobulia is related to an increase in serum erythropoietin in response to tissue hypoxia or autonomous tumor production. Since the middle of the twentieth century, the hydronephrosis is known to be a rare etiology of secondary polycythemia, with increased erythropoietin production caused by diminished oxygen sensing by the kidney, also seen in renal artery stenosis and kidney cysts. We describe a case of a 38 year old patient with polycythemia studied in the "Hospital Italiano de San Justo" (Argentina) that presented an incidental severe unilateral hydronephrosis, and nephrectomy was carried out as a final resolution of the hematological disorder. (AU)