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Archives of Disease in Childhood. Fetal... Jan 2006Severe polycythaemia in the neonate may produce symptoms due to hyperviscosity and may be associated with serious complications. Partial exchange transfusion will reduce... (Review)
Review
BACKGROUND
Severe polycythaemia in the neonate may produce symptoms due to hyperviscosity and may be associated with serious complications. Partial exchange transfusion will reduce the packed cell volume.
OBJECTIVE
To determine whether partial exchange transfusion in term infants with polycythaemia (symptomatic and asymptomatic) is associated with improved short and long term outcomes.
SEARCH STRATEGY
Medline, EMBASE, and the Cochrane Controlled Trials Register of the Cochrane Library were searched. The following keywords were used: polycythaemia, partial exchange transfusion, hyperviscosity, and limited to the newborn. This covered years 1966-2004. Abstracts of the Pediatric Academic Societies and personal files were also searched.
SELECTION CRITERIA
Randomised or quasi-randomised trials in term infants with polycythaemia and/or documented hyperviscosity were considered. Clinically relevant outcomes included were short term (resolution of symptoms, neurobehavioural scores, major complications) and long term neurodevelopmental outcome.
DATA COLLECTION AND ANALYSIS
All data for each study were extracted, assessed, and coded separately. Any disagreements were resolved by discussion.
MAIN RESULTS
Six studies were identified; five had data that could be evaluated for analysis. There is no evidence of an improvement in long term neurological outcome (mental developmental index, incidence of mental delay, and incidence of neurological diagnoses) after partial exchange transfusion in symptomatic or asymptomatic infants. There is no evidence of improvement in early neurobehavioural assessment scores (Brazelton neonatal behavioural assessment scale). Partial exchange transfusion may be associated with an earlier improvement in symptoms, but there are insufficient data to calculate the size of the effect. Necrotising enterocolitis is probably increased by partial exchange transfusion (relative risk 8.68, 95% confidence interval 1.06 to 71.1).
CONCLUSION
There is no evidence of long term benefit from partial exchange in polycythaemic infants, and the incidence of gastrointestinal injury is increased. The long term outcome is more likely to be related to the underlying cause of polycythaemia.
Topics: Blood Viscosity; Exchange Transfusion, Whole Blood; Humans; Infant, Newborn; Intellectual Disability; Polycythemia; Randomized Controlled Trials as Topic; Treatment Outcome
PubMed: 16174666
DOI: 10.1136/adc.2004.071431 -
Archives of Disease in Childhood. Fetal... Jan 2006Several studies have shown the efficacy of dilutional exchange transfusion (DET) in reducing haematocrit (Ht) and relieving clinical symptoms in neonatal polycythaemia.... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
Several studies have shown the efficacy of dilutional exchange transfusion (DET) in reducing haematocrit (Ht) and relieving clinical symptoms in neonatal polycythaemia. We conducted a systematic review to determine the efficacy of crystalloid versus colloid solutions used in DET in an effort to identify the best solution to replace red blood cells.
METHODS
The Cochrane Library, MEDLINE, and EMBASE were searched for relevant randomised controlled trials. Quality assessment and data analysis were performed using the methods and software of the Cochrane Collaboration. Relative risk (RR) and weighted mean difference (WMD) were calculated as measures of effect for categorical and continuous outcome data, respectively. Ninety five percent confidence intervals (95% CI) were calculated and a fixed effect model was used for meta-analysis.
RESULTS
Six studies with a total of 235 newborns matched our inclusion criteria. When comparing crystalloid and colloid replacement solutions for DET, there was a clinically unimportant difference in Ht at 2-6 h and at 24 h in favour of colloidal solutions (WMD 2.29% (95% CI 1.28 to 3.31) and 1.74% (95% CI 0.80 to 2.68), respectively). This difference in post DET Ht was more evident when normal saline was compared to plasma but absent when normal saline was compared to 5% albumin.
CONCLUSION
There is little difference in effectiveness between plasma, 5% albumin, and crystalloid solutions. Since normal saline is cheap, readily available, and does not carry the potential risk of transfusion associated infection, normal saline is the optimal dilutional fluid for exchange transfusion in polycythaemic neonates.
Topics: Crystalloid Solutions; Exchange Transfusion, Whole Blood; Hematocrit; Humans; Infant, Newborn; Isotonic Solutions; Plasma Substitutes; Polycythemia; Randomized Controlled Trials as Topic; Rehydration Solutions
PubMed: 16371393
DOI: 10.1136/adc.2004.063925 -
Canadian Medical Association Journal Feb 1969
Review
Topics: Animals; Central Nervous System Diseases; Erythropoiesis; Erythropoietin; Female; Genes, Regulator; Genital Diseases, Female; Hemodynamics; Humans; Hypertension; Hypoxia; Kidney; Kidney Diseases; Liver Diseases; Male; Polycythemia; Polycythemia Vera; Rats
PubMed: 4886121
DOI: No ID Found -
International Journal of Environmental... Jun 2022Ischemic retinopathy characterized by neovascularization could result from several diseases such as proliferative diabetic retinopathy, hypertensive retinopathy, and...
Ischemic retinopathy characterized by neovascularization could result from several diseases such as proliferative diabetic retinopathy, hypertensive retinopathy, and retinal vein occlusion. However, ocular ischemic conditions caused by polycythemia have rarely been described. We report the first case of polycythemia-related proliferative ischemic retinopathy in a 41-year-old male heavy smoker who had ocular ischemic condition due to secondary polycythemia. He had sudden loss of vision in his right eye vision with vitreous hemorrhage and a tortuous retinal artery. Tracing back to his history, he was a heavy smoker with more than one pack of cigarettes per day for more than 30 years. Laboratory data revealed elevated levels of hemoglobin (17.7 g/dL) and hematocrit (51.6%) without other abnormal findings. We performed retinal photocoagulation on the neovascular areas and the fibrous membrane. Additionally, the patient was advised to quit smoking. Owing to adherence to this treatment, the patient's vision gradually recovered. Although rare, polycythemia can cause retinal ischemic events and should be considered as a sight-threatening disease. Photocoagulation is effective on the regression of the neovascular lesion. Most importantly, changes in lifestyle together with smoking cessation are effective in managing secondary polycythemia. In conclusion, prevention and cessation of tobacco consumption helps improve vision health.
Topics: Adult; Diabetic Retinopathy; Humans; Male; Neovascularization, Pathologic; Polycythemia; Retinal Diseases; Smoking Cessation
PubMed: 35805729
DOI: 10.3390/ijerph19138072 -
The American Journal of Case Reports Oct 2023BACKGROUND Cerebral ischemia and hemorrhages were reported to be the main complications of polycythemia vera (PV). The relationship between PV and increased risk of the...
BACKGROUND Cerebral ischemia and hemorrhages were reported to be the main complications of polycythemia vera (PV). The relationship between PV and increased risk of the cerebrovascular events has been established. Some patients with secondary polycythemia have thromboembolic events comparable to those of PV. However, secondary polycythemia that leads to cerebrovascular events is uncommon. CASE REPORT A 35-year-old man without any prior medical history presented with mild clinical acute ischemic stroke and polycythemia. The patient then showed worsening neurological deficits that were later attributed to the concurrent cerebral venous thrombosis, which led to malignant cerebral infarction with hemorrhagic transformation, and subarachnoid hemorrhage. His polycythemia appeared to be secondary to bacterial infection. The treatments for the secondary polycythemia were first phlebotomy and intravenous hydration, followed by intravenous broad-spectrum antibiotics. PV was excluded because the JAK2 V617F mutation was absent, the patient's peripheral blood smear suggested secondary polycythemia due to bacterial infection, and there were improvements in hemoglobin, erythrocyte count, and hematocrit after intravenous antibiotics. At the 1-month follow-up, he was moderately dependent, and hemoglobin, erythrocyte count, and hematocrit were within normal limits, without receiving any further phlebotomy or cytoreductive agents. CONCLUSIONS This case highlights the plausible causation of secondary polycythemia that could lead to concomitant cerebral thrombosis and hemorrhagic events. The diagnosis of cerebral venous thrombosis should be considered in a patient who presents with headache, focal neurological deficits, polycythemia, and normal head computed tomography scan.
Topics: Male; Humans; Adult; Polycythemia; Ischemic Stroke; Polycythemia Vera; Hemorrhage; Intracranial Hemorrhages; Venous Thrombosis; Anti-Bacterial Agents; Bacterial Infections; Hemoglobins
PubMed: 37838828
DOI: 10.12659/AJCR.941507 -
American Journal of Hematology Nov 1998
Topics: Adult; Humans; Male; Polycythemia; Testosterone Congeners
PubMed: 9798672
DOI: 10.1002/(sici)1096-8652(199811)59:3<263::aid-ajh19>3.0.co;2-u -
Blood Mar 2017
Topics: Angiotensin-Converting Enzyme Inhibitors; Blood Viscosity; Disease-Free Survival; Follow-Up Studies; Hematocrit; Humans; Hypertension; Polycythemia; Polycythemia Vera
PubMed: 28028024
DOI: 10.1182/blood-2016-11-752600 -
The Journal of Physiology Sep 2021Humans suffering from polycythaemia undergo multiple circulatory adaptations including changes in blood rheology and structural and functional vascular adaptations to...
KEY POINTS
Humans suffering from polycythaemia undergo multiple circulatory adaptations including changes in blood rheology and structural and functional vascular adaptations to maintain normal blood pressure and vascular shear stresses, despite high blood viscosity. During exercise, several circulatory adaptations are observed, especially involving adrenergic and non-adrenergic mechanisms within non-active and active skeletal muscle to maintain exercise capacity, which is not observed in animal models. Despite profound circulatory stress, i.e. polycythaemia, several adaptations can occur to maintain exercise capacity, therefore making early identification of the disease difficult without overt symptomology. Pharmacological treatment of the background heightened sympathetic activity may impair the adaptive sympathetic response needed to match local oxygen delivery to active skeletal muscle oxygen demand and therefore inadvertently impair exercise capacity.
ABSTRACT
Excessive haematocrit and blood viscosity can increase blood pressure, cardiac work and reduce aerobic capacity. However, past clinical investigations have demonstrated that certain human high-altitude populations suffering from excessive erythrocytosis, Andeans with chronic mountain sickness, appear to have phenotypically adapted to life with polycythaemia, as their exercise capacity is comparable to healthy Andeans and even with sea-level inhabitants residing at high altitude. By studying this unique population, which has adapted through natural selection, this study aimed to describe how humans can adapt to life with polycythaemia. Experimental studies included Andeans with (n = 19) and without (n = 17) chronic mountain sickness, documenting exercise capacity and characterizing the transport of oxygen through blood rheology, including haemoglobin mass, blood and plasma volume and blood viscosity, cardiac output, blood pressure and changes in total and local vascular resistances through pharmacological dissection of α-adrenergic signalling pathways within non-active and active skeletal muscle. At rest, Andeans with chronic mountain sickness had a substantial plasma volume contraction, which alongside a higher red blood cell volume, caused an increase in blood viscosity yet similar total blood volume. Moreover, both morphological and functional alterations in the periphery normalized vascular shear stress and blood pressure despite high sympathetic nerve activity. During exercise, blood pressure, cardiac work and global oxygen delivery increased similar to healthy Andeans but were sustained by modifications in both non-active and active skeletal muscle vascular function. These findings highlight widespread physiological adaptations that can occur in response to polycythaemia, which allow the maintenance of exercise capacity.
Topics: Acclimatization; Altitude; Altitude Sickness; Animals; Humans; Phenotype; Polycythemia
PubMed: 34245004
DOI: 10.1113/JP281730 -
Human Genomics Jul 2018High-altitude polycythemia (HAPC) is a chronic high-altitude disease that can lead to an increase in the production of red blood cells in the people who live in the...
BACKGROUND
High-altitude polycythemia (HAPC) is a chronic high-altitude disease that can lead to an increase in the production of red blood cells in the people who live in the plateau, a hypoxia environment, for a long time. The most frequent symptoms of HAPC include headache, dizziness, breathlessness, sleep disorders, and dilation of veins. Although chronic hypoxia is the main cause of HAPC, the fundamental pathophysiologic process and related molecular mechanisms responsible for its development remain largely unclear yet.
AIM/METHODS
This study aimed to explore the related hereditary factors of HAPC in the Chinese Han and Tibetan populations. A total of 140 patients (70 Han and 70 Tibetan) with HAPC and 60 healthy control subjects (30 Han and 30 Tibetan) were recruited for a case-control association study. To explore the genetic basis of HAPC, we investigated the association between HAPC and both phosphatidylinositol-4,5-bisphosphonate 3-kinase, catalytic subunit delta gene (PIK3CD) and collagen type IV α3 chain gene (COL4A3) in Chinese Han and Tibetan populations.
RESULTS/CONCLUSION
Using the unconditional logistic regression analysis and the false discovery rate (FDR) calculation, we found that eight SNPs in PIK3CD and one SNP in COL4A3 were associated with HAPC in the Tibetan population. However, in the Han population, we did not find any significant association. Our study suggested that polymorphisms in the PIK3CD and COL4A3 were correlated with susceptibility to HAPC in the Tibetan population.
Topics: Adult; Altitude; Altitude Sickness; Autoantigens; Class I Phosphatidylinositol 3-Kinases; Collagen Type IV; Female; Genetic Association Studies; Genetic Predisposition to Disease; Genotype; Humans; Male; Middle Aged; Polycythemia; Polymorphism, Single Nucleotide; Tibet
PubMed: 30053909
DOI: 10.1186/s40246-018-0169-z -
Genes May 2023The discovery in 2005 of the V617F gain-of-function mutation in myeloproliferative neoplasms and more particularly in polycythemia vera has deeply changed the...
The discovery in 2005 of the V617F gain-of-function mutation in myeloproliferative neoplasms and more particularly in polycythemia vera has deeply changed the diagnostic and therapeutic approaches to polycythemia. More recently, the use of NGS in routine practice has revealed a large number of variants, although it is not always possible to classify them as pathogenic. This is notably the case for the E846D variant for which for which questions remain unanswered. In a large French national cohort of 650 patients with well-characterized erythrocytosis, an isolated germline heterozygous E846D substitution was observed in only two cases. For one of the patients, a family study could be performed, without segregation of the variant with the erythrocytosis phenotype. On the other hand, based on the large UK Biobank resource cohort including more than half a million UK participants, the E846D variant was found in 760 individuals, associated with a moderate increase in hemoglobin and hematocrit values, but with no significant difference to the mean values of the rest of the studied population. Altogether, our data as well as UK Biobank cohort analyses suggest that the occurrence of an absolute polycythemia cannot be attributed to the sole demonstration of an isolated E846D variant. However, it must be accompanied by other stimuli or favoring factors in order to generate absolute erythrocytosis.
Topics: Humans; Polycythemia; Polycythemia Vera; Hematocrit; Cohort Studies; Janus Kinase 2
PubMed: 37239426
DOI: 10.3390/genes14051066