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BMJ Open Apr 2022About 5.7% of the world population resides above 1500 m. It has been hypothesised that acute exposure to high-altitude locations can increase stroke risk, while chronic...
INTRODUCTION
About 5.7% of the world population resides above 1500 m. It has been hypothesised that acute exposure to high-altitude locations can increase stroke risk, while chronic hypoxia can reduce stroke-related mortality.
OBJECTIVE
This review aims to provide an overview of the available evidence on the association between long-term high-altitude exposure and ischaemic stroke.
DESIGN
A systematic review was performed from 1 January 1960 to 1 December 2021 to assess the possible link between high-altitude exposure and ischaemic stroke. The AMED, EMBASE, Cochrane Library, PubMed, MEDLINE, the Europe PubMed Central and the Latin-American bibliographic database Scielo were accessed using the University of Southampton library tool Delphis. In this review, we included population and individual-based observational studies, including cross-sectional and longitudinal studies except for those merely descriptive individual-based case reports. Studies were limited to humans living or visiting high-altitude locations for at least 28 days as a cut-off point for chronic exposure.
RESULTS
We reviewed a total of 1890 abstracts retrieved during the first step of the literature review process. The authors acquired in full text as potentially relevant 204 studies. Only 17 documents met the inclusion criteria and were finally included. Ten studies clearly suggest that living at high altitudes may be associated with an increased risk of stroke; however, five studies suggest that altitude may act as a protective factor for the development of stroke, while two studies report ambiguous results.
CONCLUSIONS
This review suggests that the most robust studies are more likely to find that prolonged living at higher altitudes reduces the risk of developing stroke or dying from it. Increased irrigation due to angiogenesis and increased vascular perfusion might be the reason behind improved survival profiles among those living within this altitude range. In contrast, residing above 3500 m seems to be associated with an apparent increased risk of developing stroke, probably linked to the presence of polycythaemia and other associated factors such as increased blood viscosity.
Topics: Altitude; Brain Ischemia; Cross-Sectional Studies; Humans; Ischemic Stroke; Stroke
PubMed: 35487749
DOI: 10.1136/bmjopen-2021-051777 -
Laryngoscope Investigative... Apr 2022The aim of this systematic review and meta-analysis was to investigate the association between obstructive sleep apnea (OSA) and erythrocytosis. (Review)
Review
OBJECTIVE
The aim of this systematic review and meta-analysis was to investigate the association between obstructive sleep apnea (OSA) and erythrocytosis.
METHODS
The PubMed, Web of Science, and Cochrane Library databases were searched for articles examining hematocrit values in patients with OSA and control individuals published till September 1, 2021. The pooled standardized mean difference (SMD) with 95% confidence interval (CI) was calculated, and subgroup analyses were performed.
RESULTS
Eleven eligible studies with a total of 4608 patients with OSA were included in this meta-analysis. Pooled outcomes revealed that hematocrit values were significantly higher in patients with OSA than in controls (SMD, 0.19; 95% CI, 0.08-0.29; < .01). When studies were stratified by disease severity, the significant differences in hematocrit values between patients and controls were only observed in the severe OSA group (SMD, 0.34; 95% CI, 0.08-0.59; < .01), but not in the mild and moderate OSA groups. In subgroup analyses according to sex and publication year, significant differences in hematocrit values between patients and controls remained stable in studies with only female patients (SMD, 0.25; 95% CI, 0.12-0.38; < .01) and in studies published after 2012 (SMD, 0.17; 95% CI, 0.06-0.28, < .01).
CONCLUSION
Our meta-analysis revealed that the hematocrit value was significantly increased in patients with OSA, particularly in severe patients, compared with that in controls. However, the elevation was modest, and the hematocrit value is expected to be within the normal range in patients with OSA. These data suggest that OSA leads to slight increases in hematocrit but does not cause clinically significant erythrocytosis.
PubMed: 35434329
DOI: 10.1002/lio2.751 -
Acta Bio-medica : Atenei Parmensis Jan 2022Philadelphia negative myeloproliferative neoplasms (MPNs) are classically characterized by excess production of terminal myeloid cells in the peripheral blood. They...
Philadelphia negative myeloproliferative neoplasms (MPNs) are classically characterized by excess production of terminal myeloid cells in the peripheral blood. They include polycythemia vera, essential thrombocythemia, and primary myelofibrosis. Among this group, primary myelofibrosis is the least common and usually carries the worst prognosis. Bone involvement in primary myelofibrosis has many forms; it affects bone marrow leading to bone marrow fibrosis, it can cause periostitis, in addition to bone and joint pain. A common radiologic finding in primary myelofibrosis is the presence of osteosclerotic lesions. However, the presence of osteolytic lesions in bone imaging was described in few reports. In this review, we searched English literature using the PRISMA guidelines looking for patients with Primary myelofibrosis who had osteolytic bone lesions to assess the impact of such findings on the disease and its effect on prognosis. We found the vast majority of lesions were painful affecting most commonly the vertebral column, pelvis, and ribs, and were detected in patients above 50 years of age with no gender preference, unfortunately they represented advanced disease stages, resulting in inadequate treatment response and poor outcome.
Topics: Bone Marrow; Humans; Myeloproliferative Disorders; Polycythemia Vera; Primary Myelofibrosis; Thrombocythemia, Essential
PubMed: 35075062
DOI: 10.23750/abm.v92i6.12350 -
Cancer Control : Journal of the Moffitt... 2021Myeloproliferative neoplasms (MPNs) are clonal hematopoietic stem cell disorders characterized by the overproduction of mature myeloid cells and are often associated...
Myeloproliferative neoplasms (MPNs) are clonal hematopoietic stem cell disorders characterized by the overproduction of mature myeloid cells and are often associated with an acquired genetic mutation of . Various epidemiological studies have indicated associations between environmental factors, lifestyle factors, and host characteristics with developing MPNs. This review aims to collect and summarize the existing information on these risk factors and establish their association with pathogenesis MPNs. Medline, Embase, PubMed, and grey literature were systematically searched using key terms for MPNs, and epidemiological study designs, that is, cross-sectional studies, case-control, and cohort, that investigated the risk factors for MPNs published were identified. Out of the 4621 articles identified, 20 met the selection criteria and were included in this review. Heterogeneity, study reliability, and bias were assessed. A significant association was found between smoking and the development of MPNs. This relationship has been explained by the substantial increase in several proinflammatory mediators and systematic oxidative stress causing hyperstimulation of myeloid compartments leading to the development of MPNs. Obesity was modestly linked with an increased risk of MPNs. The underlying mechanisms have been linked to changes in endocrine, metabolic, and inflammatory systems. No strong association was found between exposure to hazardous substances, that is, benzene and MPNs, but further investigation on the effects of increased levels and duration of exposure on hematopoietic stem cells will be beneficial. Unique individual and host variations have been determined as a modifier of disease pathogenesis and phenotype variations. There is a higher incidence rate of females developing MPNs, specifically ET, than males with higher PV incidence. Therefore, gender contributes to the heterogeneity in myeloproliferative neoplasm. Studies identified as part of this review are very diverse. Thus, further in-depth assessment to explore the role of these etiological factors associated with MPNs is warranted.
Topics: Cigarette Smoking; Environment; Environmental Exposure; Female; Humans; Inflammation Mediators; Life Style; Male; Myeloproliferative Disorders; Obesity; Oxidative Stress; Philadelphia Chromosome; Risk Factors; Sex Distribution; Sociodemographic Factors
PubMed: 34645293
DOI: 10.1177/10732748211046802 -
Cureus Aug 2021Hydroxyurea (HU) or hydroxycarbamide is a cytotoxic antimetabolite widely used to treat Philadelphia chromosome-negative Myeloproliferative Neoplasms (Ph-MPN) like... (Review)
Review
Hydroxyurea (HU) or hydroxycarbamide is a cytotoxic antimetabolite widely used to treat Philadelphia chromosome-negative Myeloproliferative Neoplasms (Ph-MPN) like Polycythemia Vera (PV), Essential Thrombocythemia (ET), and Primary Myelofibrosis (PMF). Patients with Ph-MPN are at an increased risk of Non-melanoma skin cancers (NMSC). The cause of this finding remains uncertain. In this systematic review, we would like to know if chronic use of HU in this population is responsible for the sudden onset of NMSC. The results obtained will help the patients and clinicians with early diagnosis of cutaneous lesions and in optimizing the current treatment options for MPN. We conducted a multi-database literature search, applied eligibility criteria and quality assessment tools to the studies extracted, with an intention to include only fair to high-quality articles. We analyzed six observational studies and four traditional reviews. Two out of 10 studies concluded that no relationship exists between the incidence of NMSC and HU. The remaining eight studies indicated the association. According to these studies, the possible risk factors include old age, excessive exposure to sunlight, higher doses, and prolonged HU therapy duration. Ultraviolet (UV) radiation and HU play a combined role in carcinogenesis. Periodic dermatologic screening is essential in these patients. Prompt biopsy and accurate diagnosis can prevent the progression of cancer and decrease the associated morbidity and mortality. True incidence and causation cannot be ascertained due to the scarcity of research on this topic. Multi-center prospective studies in large groups of Ph-MPN patients are recommended to determine the temporal relationship between NMSC and HU treatment.
PubMed: 34527458
DOI: 10.7759/cureus.16978 -
Transplant International : Official... Nov 2021Post-transplant erythrocytosis (PTE) can occur in up to 10-16% after kidney transplant (KT). However, the post-transplant outcomes of recipients with PTE in the... (Meta-Analysis)
Meta-Analysis
Post-transplant erythrocytosis (PTE) can occur in up to 10-16% after kidney transplant (KT). However, the post-transplant outcomes of recipients with PTE in the literature were conflicting. We performed systematic review and meta-analysis of published studies to evaluate risk factors of PTE as well as outcomes of recipients who developed PTE compared with controls. A literature search was conducted evaluating all literature from existence through February 2, 2021, using MEDLINE and EMBASE. Data from each study were combined using the random-effects model. (PROSPERO: CRD42021230377). Thirty-nine studies from July 1982 to January 2021 were included (7,099 KT recipients). The following factors were associated with PTE development: male gender (pooled RR = 1.62 [1.38, 1.91], I = 39%), deceased-donor KT (pooled RR = 1.18 [1.03, 1.35], I = 32%), history of smoking (pooled RR = 1.36 [1.11, 1.67], I = 13%), underlying polycystic kidney disease (PKD) (pooled RR=1.56 [1.21, 2.01], I =44%), and pretransplant dialysis (pooled RR=1.6 [1.02, 2.51], I =46%). However, PTE was not associated with outcomes of interest, including overall mortality, death-censored graft failure, and thromboembolism. Our meta-analysis demonstrates that male gender, deceased-donor KT, history of smoking, underlying PKD, and pretransplant dialysis were significantly associated with developing PTE. However, with proper management, PTE has no impact on prognosis of KT patients.
Topics: Adult; Humans; Kidney Transplantation; Male; Polycythemia; Risk Factors; Transplant Recipients; Transplants
PubMed: 34412165
DOI: 10.1111/tri.14016 -
Life (Basel, Switzerland) Jul 2021Myeloproliferative neoplasms (MPNs) are rare, clonal disorders of the hematopoietic stem cell in which an uncontrolled proliferation of terminally differentiated myeloid... (Review)
Review
Myeloproliferative neoplasms (MPNs) are rare, clonal disorders of the hematopoietic stem cell in which an uncontrolled proliferation of terminally differentiated myeloid cells is noted. Polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF) are included in the category of Philadelphia-negative, so-called classical MPNs. The potential applications of liquid biopsy and liquid biopsy-based biomarkers have not been explored in MPNs until now. Thus, a systematic search was computed in PubMed/MEDLINE, Web of Science and The Cochrane Library and, in total, 198 potentially relevant papers were detected. Following the removal of duplicates ( = 85), 113 records were screened. After the exclusion of irrelevant manuscripts based on the screening of their titles and abstracts ( = 81), we examined the full texts of 33 manuscripts. Finally, after we applied the exclusion and inclusion criteria, 27 original articles were included in this review. Overall, the data analyzed in this review point out that liquid biopsy and liquid biopsy-based biomarkers (cell-free DNA, extracellular vesicles, microparticles, circulating endothelial cells) could be used in MPNs for diagnostic and prognostic purposes. Future research is needed to clarify whether this technique can be employed to differentiate between MPN subtypes and secondary causes of erythrocytosis, thrombocytosis and myelofibrosis, as well as to predict the development of thrombosis.
PubMed: 34357048
DOI: 10.3390/life11070677 -
Cancers Jun 2021Multiple recurrent somatic mutations have recently been identified in association with myeloproliferative neoplasms (MPN). This meta-analysis aims to assess the pooled... (Review)
Review
Multiple recurrent somatic mutations have recently been identified in association with myeloproliferative neoplasms (MPN). This meta-analysis aims to assess the pooled prevalence of gene mutations among patients with MPN. Six databases (PubMed, Scopus, ScienceDirect, Google Scholar, Web of Science and Embase) were searched for relevant studies from inception till September 2020, without language restrictions. The eligibility criteria included --negative MPN adults with gene mutations. A random-effects model was used to estimate the pooled prevalence with 95% confidence intervals (CIs). Subgroup analyses explored results among different continents and countries, WHO diagnostic criteria, screening methods and types of MF. Quality assessment was undertaken using the Joanna Briggs Institute critical appraisal tool. The study was registered with PROSPERO (CRD42020212223). Thirty-five studies were included ( = 5121, 47.1% female). Overall, the pooled prevalence of gene mutations in MPN patients was 15.5% (95% CI: 12.1-19.0%, = 94%). Regional differences explained a substantial amount of heterogeneity. The prevalence of gene mutations among the three subtypes PV, ET and MF were 16.8%, 9.8% and 15.7%, respectively. The quality of the included studies was determined to be moderate-high among 83% of the included studies. Among patients with --negative MPN, the overall prevalence of gene mutations was 15.5%.
PubMed: 34203097
DOI: 10.3390/cancers13123078 -
Ultrasound in Obstetrics & Gynecology :... Nov 2021Monochorionic twins with twin-twin transfusion syndrome (TTTS) treated with fetoscopic laser photocoagulation (FLP) are at increased risk of neurodevelopmental... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
Monochorionic twins with twin-twin transfusion syndrome (TTTS) treated with fetoscopic laser photocoagulation (FLP) are at increased risk of neurodevelopmental impairment (NDI). This meta-analysis aimed to identify the prevalence of and perinatal risk factors for NDI in TTTS survivors treated with FLP.
METHODS
We performed a search in PubMed, EMBASE, Scopus and Web of Science, from inception to 13 February 2021, for studies evaluating perinatal risk factors for NDI in children diagnosed prenatally with TTTS managed by FLP. Data on severity of TTTS at the time of diagnosis, defined according to the Quintero staging system, FLP-related complications and perinatal outcomes were compared between children with a history of TTTS treated with FLP with and those without NDI, which was defined as performance on a cognitive or developmental assessment tool ≥ 2 SD below the mean or a defined motor or sensory disability. A random-effects model was used to pool the mean differences or odds ratios (OR) with the corresponding 95% CIs. Heterogeneity was assessed using the I statistic.
RESULTS
Nine studies with a total of 1499 TTTS survivors were included. The overall incidence of NDI was 14.0% (95% CI, 9.0-18.0%). The occurrence of NDI in TTTS survivors was associated with later gestational age (GA) at FLP (mean difference, 0.94 weeks (95% CI, 0.50-1.38 weeks); P < 0.0001, I = 0%), earlier GA at delivery (mean difference, -1.44 weeks (95% CI, -2.28 to -0.61 weeks); P = 0.0007, I = 49%) and lower birth weight (mean difference, -343.26 g (95% CI, -470.59 to -215.92 g); P < 0.00001, I = 27%). Evaluation of different GA cut-offs showed that preterm birth before 32 weeks was associated with higher risk for NDI later in childhood (OR, 2.25 (95% CI, 1.02-4.94); P = 0.04, I = 35%). No statistically significant difference was found between cases with and those without NDI with respect to Quintero stage of TTTS, recipient or donor status, development of postlaser twin anemia-polycythemia sequence, recurrence of TTTS and incidence of small- for-gestational age or cotwin fetal demise.
CONCLUSIONS
TTTS survivors with later GA at the time of FLP, earlier GA at delivery and lower birth weight are at higher risk of developing NDI. No significant association was found between Quintero stage of TTTS and risk of NDI. Our findings may be helpful for parental counseling and highlight the need for future studies to understand better the risk factors for NDI in TTTS survivors. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.
Topics: Diseases in Twins; Female; Fetofetal Transfusion; Fetoscopy; Gestational Age; Humans; Incidence; Laser Coagulation; Neurodevelopmental Disorders; Postoperative Complications; Pregnancy; Pregnancy, Twin; Premature Birth; Risk Factors; Twins
PubMed: 34097320
DOI: 10.1002/uog.23706 -
Cancer Imaging : the Official... Apr 2021Diagnostic and treatment response criteria for the JAK2/CALR/MPL mutation-related myeloproliferative neoplasms (MPNs) are largely based on bone marrow (BM) biopsy...
BACKGROUND
Diagnostic and treatment response criteria for the JAK2/CALR/MPL mutation-related myeloproliferative neoplasms (MPNs) are largely based on bone marrow (BM) biopsy results. However, these biopsies have several limitations, such as the risk of sampling error. Also, the prognostic impact of BM abnormalities is largely unclear. Although not currently used in clinical practice, imaging techniques might offer additional information. In this review, we investigated the value of BM, liver, and spleen imaging for diagnosis, prognostication, and response monitoring of the JAK2/CALR/MPL mutation-related MPNs (i.e. essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis (MF)).
METHODS
A systematic literature search was performed via PubMed, Embase and the Cochrane Library up to 2020 March 26th. Of 5505 identified records, 55 publications met the eligibility criteria (i.e. containing original data on the imaging appearance of BM, spleen, or liver in adult ET, PV, or MF patients, published in a peer-reviewed journal, written in English).
RESULTS
Many explorative studies described imaging features, sometimes with comparisons to clinical characteristics. Studies reporting measures of diagnostic accuracy included 1) splenic transient elastography to predict BM fibrosis grade in MF, 2) dynamic contrast-enhanced MRI to discern MF patients from ET patients and healthy controls, and 3) 18-fluorodeoxyglucose PET to detect residual disease after stem cell transplantation in MF. The diagnostic accuracies of radiography and Tc-colloid scintigraphy were derived from several other articles. Except for the study on 18-fluorodeoxyglucose PET, we established substantial concerns regarding risk of bias and applicability across these studies, using the QUADAS-2 tool. Three publications described a correlation between imaging results and prognosis, of which one quantified the effect.
CONCLUSIONS
Based on current data, MRI (T1-weighted/STIR, Dixon) seems especially promising for the evaluation of BM fat content - and indirectly cellularity/fibrosis - in MF, and possibly for estimating BM cellularity in ET/PV. 18-fluorodeoxyglucose and 18-fluorothymidine PET/CT might be useful for evaluating BM fibrosis, with good reported accuracy of the former for the diagnosis of residual disease. Further research on these and other techniques is warranted to determine their exact value. Future researchers should improve methodology and focus on evaluation of diagnostic accuracy and prognostic implications of results.
Topics: Adult; Bone Marrow; Female; Follow-Up Studies; Humans; Liver; Male; Myeloproliferative Disorders; Positron Emission Tomography Computed Tomography; Prognosis; Spleen
PubMed: 33879266
DOI: 10.1186/s40644-021-00405-7