Asunto(s)
Eritropoyetina , Policitemia , Neoplasias Uterinas , Humanos , Femenino , Policitemia/complicaciones , Policitemia/diagnóstico , SíndromeRESUMEN
Vizcarra-Vizcarra, Cristhian A., Eduardo Chávez-Velázquez, Carmen Asato-Higa, and Abdías Hurtado-Aréstegui. Treatment of focal and segmental glomerulosclerosis secondary to high altitude polycythemia with acetazolamide. High Alt Med Biol. 23:286-290, 2022.-Focal segmental glomerulosclerosis (FSGS) is a morphological pattern, caused by glomerular injury and is the leading cause of nephrotic syndrome in adults. We present the case of a 59-year-old female patient, resident of a high-altitude city (3,824 m), who had polycythemia and nephrotic syndrome. A renal biopsy was performed, and the findings were compatible with FSGS. The patient received phlebotomy 500 ml three times, which reduced, partially, the hemoglobin concentration. However, she had refractory proteinuria, despite the use of enalapril and spironolactone. We observed that proteinuria worsened with the increase in hemoglobin levels. So, she was treated with acetazolamide 250 mg bid for 4 months, which reduced proteinuria and hemoglobin. During the coronavirus disease 2019 (COVID-19) pandemic, the patient did not take acetazolamide and again, she had an increase in hemoglobin and proteinuria levels. We conclude that acetazolamide may be an effective treatment in FSGS due to high altitude polycythemia.
Asunto(s)
Mal de Altura , COVID-19 , Glomeruloesclerosis Focal y Segmentaria , Síndrome Nefrótico , Policitemia , Acetazolamida/uso terapéutico , Adulto , Altitud , Mal de Altura/complicaciones , Mal de Altura/tratamiento farmacológico , Femenino , Glomeruloesclerosis Focal y Segmentaria/complicaciones , Glomeruloesclerosis Focal y Segmentaria/etiología , Humanos , Persona de Mediana Edad , Síndrome Nefrótico/complicaciones , Síndrome Nefrótico/patología , Policitemia/complicaciones , Policitemia/etiología , Proteinuria/etiologíaRESUMEN
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)
Asunto(s)
Humanos , Animales , Masculino , Adulto , Persona de Mediana Edad , Policitemia/diagnóstico , Pielonefritis/diagnóstico , Infecciones Urinarias/complicaciones , Eritropoyetina/sangre , Hidronefrosis/diagnóstico , Nefrectomía/tendencias , Policitemia/complicaciones , Policitemia/etiología , Pielonefritis/sangre , Obstrucción de la Arteria Renal/patología , Dolor de la Región Lumbar , Hipoxia-Isquemia Encefálica/patología , Eritrocitos/fisiología , Enfermedades Renales Quísticas/patología , Disuria , Fiebre , Hidronefrosis/cirugía , Hidronefrosis/complicaciones , Anemia , Nefrectomía/métodosRESUMEN
Miele, Catherine H., Alan R. Schwartz, Robert H. Gilman, Luu Pham, Robert A. Wise, Victor G. Davila-Roman, Jonathan C. Jun, Vsevolod Y. Polotsky, J. Jaime Miranda, Fabiola Leon-Velarde, and William Checkley. Increased cardiometabolic risk and worsening hypoxemia at high altitude. High Alt Med Biol. 17:93-100, 2016.-Metabolic syndrome, insulin resistance, diabetes, and dyslipidemia are associated with an increased risk of cardiovascular disease. While excessive erythrocytosis is associated with cardiovascular complications, it is unclear how worsening hypoxemia of any degree affects cardiometabolic risk factors in high-altitude populations. We studied the relationship between daytime resting oxyhemoglobin saturation and cardiometabolic risk factors in adult participants living in Puno, Peru (3825 m above sea level). We used multivariable logistic regression models to study the relationship between having a lower oxyhemoglobin saturation and markers of cardiometabolic risk. Nine hundred and fifty-four participants (mean age 55 years, 52% male) had information available on pulse oximetry and markers of cardiometabolic risk. Average oxyhemoglobin saturation was 90% (interquartile range 88%-92%) and 43 (4.5%) had excessive erythrocytosis. Older age, decreased height-adjusted lung function, and higher body mass index (BMI) were associated with having an oxyhemoglobin saturation ≤85%. When adjusting for age, sex, socioeconomic status, having excessive erythrocytosis, and site, we found that each 5% decrease in oxyhemoglobin saturation was associated with a higher adjusted odds of metabolic syndrome (OR = 1.35, 95% CI: 1.07-1.72, p < 0.04), insulin resistance as defined by homeostasis model assessment-insulin resistance (HOMA-IR) >2 mass units (OR = 1.29, 95% CI: 1.00-1.67, p < 0.05), hemoglobin A1c ≥6.5% (OR = 1.66, 95% CI: 1.09-2.51, p < 0.04), and high sensitivity C-reactive protein (hs-CRP) ≥3 mg/L (OR = 1.46, 95% CI: 1.09-1.96, p < 0.01). In high-altitude populations in Puno, Peru, a higher BMI and lower pulmonary function were associated with lower resting daytime oxyhemoglobin saturation. Lower resting oxyhemoglobin saturation, in turn, was associated with higher odds of having multiple unfavorable cardiometabolic factors. Worsening hypoxia of any degree in high-altitude dwellers may be an independent risk factor for cardiovascular disease.
Asunto(s)
Altitud , Enfermedades Cardiovasculares/etiología , Progresión de la Enfermedad , Hipoxia/complicaciones , Síndrome Metabólico/etiología , Adulto , Biomarcadores/sangre , Índice de Masa Corporal , Proteína C-Reactiva/análisis , Femenino , Humanos , Hipoxia/sangre , Hipoxia/fisiopatología , Resistencia a la Insulina , Modelos Logísticos , Masculino , Persona de Mediana Edad , Oximetría , Oxihemoglobinas/análisis , Perú , Policitemia/sangre , Policitemia/complicaciones , Descanso/fisiología , Factores de RiesgoRESUMEN
Abstract Bartter syndrome comprises a group of rare autosomal-recessive salt-losing disorders with distinct phenotypes, but one unifying pathophysiology consisting of severe reductions of sodium reabsorption caused by mutations in five genes expressed in the thick ascending limb of Henle, coupled with increased urinary excretion of potassium and hydrogen, which leads to hypokalemic alkalosis. Bartter syndrome type IV, caused by loss-of-function mutations in barttin, a subunit of chloride channel CLC-Kb expressed in the kidney and inner ear, usually occurs in the antenatal-neonatal period. We report an unusual case of late onset presentation of Bartter syndrome IV and mild phenotype in a 20 years-old man who had hypokalemia, deafness, secondary hyperparathyroidism and erythrocytosis.
Resumo A síndrome de Bartter compreende um grupo raro de doenças autossômicas recessivas perdedoras de sal, decorrentes de mutações em genes expressos na porção ascendente espessa da alça de Henle, com fenótipos distintos, porém fisiopatogenia única, que consiste em redução severa da reabsorção de sódio, e aumento da excreção urinária de hidrogênio e potássio, levando à alcalose hipocalêmica. A síndrome de Bartter tipo IV, causada por mutações com perda de função da bartina, uma subunidade do canal de cloro CLC-Kb expressa no rim e ouvido interno, geralmente se apresenta nos períodos ante e neonatal. No presente relato, descreve-se um caso não usual de síndrome de Bartter tipo IV com apresentação tardia e fenótipo atenuado, diagnosticado por análise molecular, em um homem adulto de 20 anos que se apresentava com hipocalemia, surdez, hiperparatireoidismo secundário e eritrocitose.
Asunto(s)
Humanos , Masculino , Adulto Joven , Síndrome de Bartter/complicaciones , Policitemia/complicaciones , Alcalosis/metabolismo , Brasil , Síndrome de Bartter/genética , Canales de Cloruro/genética , Canales de Cloruro/metabolismo , Sordera/complicaciones , Hiperparatiroidismo Secundario/complicaciones , Hipopotasemia/complicaciones , Enfermedades de Inicio Tardío/genética , Fenotipo , Potasio/orinaRESUMEN
Bartter syndrome comprises a group of rare autosomal-recessive salt-losing disorders with distinct phenotypes, but one unifying pathophysiology consisting of severe reductions of sodium reabsorption caused by mutations in five genes expressed in the thick ascending limb of Henle, coupled with increased urinary excretion of potassium and hydrogen, which leads to hypokalemic alkalosis. Bartter syndrome type IV, caused by loss-of-function mutations in barttin, a subunit of chloride channel CLC-Kb expressed in the kidney and inner ear, usually occurs in the antenatal-neonatal period. We report an unusual case of late onset presentation of Bartter syndrome IV and mild phenotype in a 20 years-old man who had hypokalemia, deafness, secondary hyperparathyroidism and erythrocytosis.
Asunto(s)
Síndrome de Bartter/complicaciones , Policitemia/complicaciones , Alcalosis/metabolismo , Síndrome de Bartter/genética , Brasil , Canales de Cloruro/genética , Canales de Cloruro/metabolismo , Sordera/complicaciones , Humanos , Hiperparatiroidismo Secundario/complicaciones , Hipopotasemia/complicaciones , Enfermedades de Inicio Tardío/genética , Masculino , Fenotipo , Potasio/orina , Adulto JovenRESUMEN
In the last few years, genetic and functional studies have provided important insight on the pathophysiology of excessive erythrocytosis (EE), the main sign of Chronic Mountain Sickness (CMS). The recent finding of the association of the CMS phenotype with a single-nucleotide polymorphism (SNP) in the Sentrin-specific Protease 1 (SENP1) gene, and its differential expression pattern in Andean highlanders with and without CMS, has triggered large interest in high-altitude studies because of the potential role of its gene product in the control of erythropoiesis. The SENP1 gene encodes for a protease that regulates the function of hypoxia-relevant transcription factors such as Hypoxia-Inducible Factor (HIF) and GATA, and thus might have an erythropoietic regulatory role in CMS through the modulation of the expression of erythropoietin (Epo) or Epo receptors. The different physiological patterns in the Epo-EpoR system found among Andeans, even among highlanders with CMS, together with their different degrees of erythropoietic response, might indicate specific underlying genetic backgrounds, which in turn might reflect different levels of adaptation to lifelong high-altitude hypoxia. This minireview discusses recent genetic findings potentially underlying EE and CMS, and their possible physiological mechanisms in Andean highlanders.
Asunto(s)
Mal de Altura/sangre , Mal de Altura/genética , Policitemia/sangre , Policitemia/genética , Altitud , Mal de Altura/complicaciones , Mal de Altura/fisiopatología , Enfermedad Crónica , Humanos , Policitemia/complicaciones , Policitemia/fisiopatología , América del SurRESUMEN
A 67-year-old woman with a history of hypertension and type 2 diabetes mellitus was admitted to the hospital due to aphasia and left-sided hemiparesis during the past 5 h with resolution of symptoms within 24 h. On admission laboratory analysis showed haemoglobin 19.2 g/dL and haematocrit 55.1%. Cerebral CT scan was also performed on admission revealing periventricular leucoaraiosis. Studies to investigate the cause of erythrocytosis were started and elevated erythropoietin levels were found. In order to investigate a secondary cause of erythrocytosis an abdominal ultrasound was conducted revealing a left renal mass. CT scans of thorax, abdomen and pelvis confirmed renal mass 8 × 8 cm of diameter, suggestive of neoplasm without associated lymphadenopathy or metastases. Radical nephrectomy was performed and a pathological diagnosis demonstrated clear cell renal cell carcinoma and was staged as T2aN0M0.
Asunto(s)
Carcinoma de Células Renales/complicaciones , Ataque Isquémico Transitorio/etiología , Neoplasias Renales/complicaciones , Síndromes Paraneoplásicos/complicaciones , Policitemia/complicaciones , Anciano , Carcinoma de Células Renales/cirugía , Diagnóstico Diferencial , Femenino , Humanos , Neoplasias Renales/cirugía , Nefrectomía , Resultado del TratamientoRESUMEN
La corea es un trastorno del movimiento que tiene a la eritrocitosis como causa poco frecuente. La eritrocitosis o poliglobulia es el aumento de la masa eritrocitaria absoluta y su causa primaria más frecuente es la policitemia vera. Entre las causas secundarias adquiridas figura la eritrocitosis por hipoxia central, como la que ocurre en los habitantes de grandes alturas. La corea es una manifestación neurológica rara de la eritrocitosis, se presenta en 0,5 a 2% de estos pacientes. Se reporta el caso de un paciente de sexo masculino de 71 años de edad que presentó corea generalizada, de inicio súbito, a predominio orolinguofacial y de extremidades inferiores, secundario a eritrocitosis adquirida, que mejoró tras la disminución del hematocrito mediante sesiones sucesivas de flebotomías.
Chorea is a movement disorder which is rarely caused by erythrocytosis. Erithrocytosis or polycythemia is the augmentation of the absolute erythrocytic mass and its most common primary cause is polycythemia vera. Some of the secondary causes are erythrocytosis by central hipoxia occurring in people who live in the highlands. Chore is a rare neurological manifestation of erythrocytosis occurring in 0.5 to 2% of these patients. There was a report of a 71 year-old male patient with generalized chorea of sudden onset predominant in mouth, tongue and face and lower limbs, secondary to acquired erythrocytosis, which improved after the number of erythrocytes decreased through successive sessions of phlebotomy.
Asunto(s)
Anciano , Humanos , Masculino , Altitud , Corea/etiología , Policitemia/complicacionesRESUMEN
The median survival of patients with truncus arteriosus is five weeks of age with rare cases reaching adulthood. The longest reported survivor with balanced ventricles, as the index case has, is 38 years of age. The index case is a 46-year old male with Type 3 truncus arteriosus. His case has never been documented in the English Literature as far as the author is aware.
Asunto(s)
Circulación Colateral , Anomalías de los Vasos Coronarios/fisiopatología , Hipertensión Pulmonar/fisiopatología , Tronco Arterial Persistente/fisiopatología , Anomalías de los Vasos Coronarios/complicaciones , Anomalías de los Vasos Coronarios/mortalidad , Humanos , Hipertensión Pulmonar/complicaciones , Hipertensión Pulmonar/mortalidad , Masculino , Persona de Mediana Edad , Policitemia/complicaciones , Tronco Arterial Persistente/complicaciones , Tronco Arterial Persistente/mortalidadRESUMEN
Chorea is a movement disorder which is rarely caused by erythrocytosis. Erithrocytosis or polycythemia is the augmentation of the absolute erythrocytic mass and its most common primary cause is polycythemia vera. Some of the secondary causes are erythrocytosis by central hipoxia occurring in people who live in the highlands. Chore is a rare neurological manifestation of erythrocytosis occurring in 0.5 to 2% of these patients. There was a report of a 71 year-old male patient with generalized chorea of sudden onset predominant in mouth, tongue and face and lower limbs, secondary to acquired erythrocytosis, which improved after the number of erythrocytes decreased through successive sessions of phlebotomy.
Asunto(s)
Altitud , Corea/etiología , Policitemia/complicaciones , Anciano , Humanos , MasculinoRESUMEN
BACKGROUND: We report a 21-year-old male, presenting with erythromelalgia and polycythemia. A solid renal mass of the lower pole of the right kidney was discovered. The patient was subjected to a right open partial nephrectomy. The pathological study of the surgical specimen showed a metanephric adenoma of the kidney. The patient had an uneventful postoperative evolution. Currently the patient is in good health without evidence of recurrence of the tumor and normal hematological parameters.
Asunto(s)
Adenoma/complicaciones , Carcinoma de Células Renales/complicaciones , Eritromelalgia/complicaciones , Neoplasias Renales/complicaciones , Policitemia/complicaciones , Adenoma/patología , Humanos , Neoplasias Renales/patología , Masculino , Adulto JovenRESUMEN
Background: We report a 21-year-old male, presenting with erythromelalgia and polycythe-mia. A solid renal mass of the lower pole of the right kidney was discovered. The patient was subjected to a right open partial nephrectomy. The pathological study of the surgical specimen showed a metanephric adenoma of the kidney. The patient had an uneventful postoperative evolution. Currently the patient is in good health without evidence of recurrence of the tumor and normal hematological parameters.
Asunto(s)
Humanos , Masculino , Adulto Joven , Adenoma/complicaciones , Carcinoma de Células Renales/complicaciones , Eritromelalgia/complicaciones , Neoplasias Renales/complicaciones , Policitemia/complicaciones , Adenoma/patología , Neoplasias Renales/patologíaRESUMEN
O diabetes mellitus gestacional (DMG) está associado a um risco aumentado de complicações fetais, neonatais e no desenvolvimento a longo prazo. As taxas de aborto espontâneo, natimorto, mal formações congênitas e morbidade e mortalidade perinatal são maiores em filhos de mães diabéticas. As principais complicações neonatais são: macrossomia, hipoglicemia neonatal, deficiência de ferro, alterações da função cardiorrespiratória, hiperbilirrubinemia, anormalidades neurológicas, hipocalcemia, hipomagnesemia e policitemia. A macrossomia predispõe a lesões do parto, especialmente distócia de ombro, maior risco de lesão do plexo braquial, fraturas de clavícula ou do úmero, asfixia perinatal, e, menos frequentemente, hemorragia subdural e paralisia facial. O controle glicêmico rigoroso pré-concepção e durante a gestação associa-se com menor morbimortalidade perinatal. Assim, o controle do DMG representa tarefa de fundamental importância para impedir sequelas em neonatais. (AU)
The gestational diabetes mellitus (GDM) is associated with an increased risk of fetal, neonatal, and possibly long-term complications. The rates of spontaneous abortion, stillbirth, congenital malformations, and perinatal morbidity and mortality are higher in infants of a diabetic mother than in pregnancies with normal glycemic control. The main neonatal complications are: macrosomia, neonatal hypoglycemia, iron deficiency, changes in cardiac and respiratory function, hyperbilirubinemia, neurological abnormalities, hypocalcemia, hypomagnesemia and polycythemia. Macrosomia predisposes to birth injury, especially shoulder dystocia, increased risk of brachial plexus injury, clavicular or humeral fractures, perinatal asphyxia, and, less often, subdural hemorrhage and facial palsy. Strict glycemic control preconception and during pregnancy is associated with lower perinatal morbidity and mortality. Thus, GDM control is of paramount importance to prevent neonatal harm. (AU)
Asunto(s)
Humanos , Femenino , Embarazo , Recién Nacido , Complicaciones del Embarazo , Macrosomía Fetal/complicaciones , Diabetes Gestacional , Policitemia/complicaciones , /complicaciones , Glucemia , Plexo Braquial/lesiones , Clavícula/lesiones , Hiperinsulinismo Congénito/complicaciones , Distocia , Parálisis Facial/complicaciones , Fracturas del Húmero/complicaciones , Hiperbilirrubinemia/complicaciones , Malformaciones del Sistema Nervioso/complicacionesRESUMEN
Chronic mountain sickness (CMS), a lack of adaptation to altitude characterized by excessive erythrocytosis (EE), is a health problem associated with life at high altitude. The erythropoietic process is regulated by both erythropoietin and testosterone. Zinc (Zn) is known to be related with testosterone and hemoglobin levels; meanwhile, nitric oxide was also associated with adaptation to high altitude. The aim of this study was to determine the relationship of hemoglobin and CMS score with serum levels of zinc, total testosterone (TT), calculated free testosterone (cFT), bioavailable testosterone (BAT), hemoglobin, and nitric oxide in men at high altitude with or without EE. Men residing in Lima (150 m) and Cerro de Pasco (4,340 m), Peru, were divided into three groups: (1) low altitude, (2) high altitude without EE (hemoglobin < 21 g/dl), and (3) high altitude with EE (hemoglobin ≥ 21 g/dl). Adjusted multivariable regression models showed that serum testosterone (total or free) and Zn levels were independently correlated with increased hemoglobin levels. Similarly, hemoglobin was positively related with signs/symptoms of CMS; however, both increased the serum Zn and the nitric oxide levels correlated with reduced risk for signs/symptoms of CMS. In conclusion, higher serum testosterone levels and Zn levels were associated with EE, and low scores of signs/symptoms of CMS were associated with higher Zn and nitric oxide levels.
Asunto(s)
Mal de Altura/sangre , Policitemia/sangre , Testosterona/sangre , Zinc/sangre , Adaptación Fisiológica , Adulto , Mal de Altura/complicaciones , Mal de Altura/fisiopatología , Enfermedad Crónica , Hemoglobinas/fisiología , Humanos , Masculino , Persona de Mediana Edad , Óxido Nítrico/sangre , Policitemia/complicaciones , Policitemia/fisiopatologíaAsunto(s)
Neoplasias Abdominales/complicaciones , Hipertensión Maligna/etiología , Neoplasias Primarias Múltiples/complicaciones , Paraganglioma Extraadrenal/complicaciones , Policitemia/complicaciones , Neoplasias Abdominales/patología , Neoplasias Abdominales/cirugía , Adolescente , Eritropoyetina/sangre , Femenino , Humanos , Neoplasias Primarias Múltiples/patología , Neoplasias Primarias Múltiples/cirugía , Paraganglioma Extraadrenal/patología , Paraganglioma Extraadrenal/cirugía , Atención Perioperativa , Obstrucción de la Arteria Renal/complicacionesAsunto(s)
Humanos , Psoriasis/complicaciones , Psoriasis/etiología , Psoriasis/tratamiento farmacológico , Adyuvantes Inmunológicos/uso terapéutico , Fármacos Dermatológicos/uso terapéutico , Interferón-alfa/efectos adversos , Policitemia/complicaciones , Psoriasis/genética , Psoriasis/inducido químicamente , Queratosis/complicacionesRESUMEN
Hb Johnstown [beta109(G11)Val-->Leu], a high oxygen affinity hemoglobin (Hb) variant associated with beta0-thalassemia (thal) [IVS-I-1 (G-->A)], was identified in an 8-year-old girl referred to our laboratory because of erythrocytosis and a left-shifted oxygen dissociation curve (ODC). The phylogenetic tree showed that the mother was heterozygous for the Hb variant and the father was a beta0-thal carrier. This Hb variant, with normal electrophoresis, was characterized at the DNA level by beta gene sequencing. The amino acid substitution potentially disrupts alpha1beta1 contacts i n the deoxyHb conformation, thus shifting the equilibrium towards the high affinity oxyHb conformation. The erythrocytosis and low values for actual P50 due to Hb Johnstown were more marked due to the co-inheritance of the beta0-thal.
Asunto(s)
Hemoglobinas Anormales/genética , Oxígeno/metabolismo , Talasemia beta/genética , Niño , Femenino , Hemoglobinas Anormales/metabolismo , Humanos , Padres , Policitemia/complicaciones , Policitemia/metabolismo , Talasemia beta/complicaciones , Talasemia beta/metabolismoRESUMEN
In pulmonary hypertension (PH), defective plasma von Willebrand factor (vWF) lacking the larger multimers with increased concentration of low-molecular-weight fractions (LMW) has been reported, although the mechanisms involved are not completely known. Altered platelet behavior may be involved in this alteration; this hypothesis was investigated in 10 patients with PH associated with chronic hypoxemia and erythrocytosis (age 13 to 51 years, mean pulmonary artery pressure 38 to 98 mmHg). The possible influence of the hematocrit (Hct) and decreased oxygen saturation (SpO2) on vWF abnormalities was examined. Patients were evaluated before and after therapeutic hemodilution. vWF alterations were quantified using the ratio of LMW/total multimers (densitometric analysis of luminographs after Western blotting). Platelet count and activation state (plasma levels of beta-thromboglobulin, enzyme-linked immunosorbent assay), the Hct and SpO2 were also assessed before and after hemodilution. Platelet activation and consumption were suggested by increased plasma beta-thromboglobulin (p=0.0444) with decreased platelet count (p<0.001). Altered vWF LMW/total ratio correlated significantly with decreased platelet count (p=0.0066) and low SpO2 (p=0.0088). The effects of both variables were independent and additive (p=0.0031, multiple regression). Hemodilution was followed by an increase in platelet count (p=0.0013) associated with improvement of LMW/total ratio (p=0.0079). Residual vWF alterations were associated with persistent hypoxemia and residual platelet activation (plasma beta-thromboglobulin still increased). These data suggest a common mechanism for platelet and vWF abnormalities in these chronically hypoxic PH patients. Hypoxia itself may play a role, possibly inducing endothelial release of unprocessed (LMW) vWF molecules.