In patients with acquired aplastic anemia, destruction of hematopoietic cells by the immune system leads to pancytopenia. Patients have a response to immunosuppressive therapy, but myelodysplastic ...syndromes and acute myeloid leukemia develop in about 15% of the patients, usually many months to years after the diagnosis of aplastic anemia.
We performed next-generation sequencing and array-based karyotyping using 668 blood samples obtained from 439 patients with aplastic anemia. We analyzed serial samples obtained from 82 patients.
Somatic mutations in myeloid cancer candidate genes were present in one third of the patients, in a limited number of genes and at low initial variant allele frequency. Clonal hematopoiesis was detected in 47% of the patients, most frequently as acquired mutations. The prevalence of the mutations increased with age, and mutations had an age-related signature. DNMT3A-mutated and ASXL1-mutated clones tended to increase in size over time; the size of BCOR- and BCORL1-mutated and PIGA-mutated clones decreased or remained stable. Mutations in PIGA and BCOR and BCORL1 correlated with a better response to immunosuppressive therapy and longer and a higher rate of overall and progression-free survival; mutations in a subgroup of genes that included DNMT3A and ASXL1 were associated with worse outcomes. However, clonal dynamics were highly variable and might not necessarily have predicted the response to therapy and long-term survival among individual patients.
Clonal hematopoiesis was prevalent in aplastic anemia. Some mutations were related to clinical outcomes. A highly biased set of mutations is evidence of Darwinian selection in the failed bone marrow environment. The pattern of somatic clones in individual patients over time was variable and frequently unpredictable. (Funded by Grant-in-Aid for Scientific Research and others.).
With increasing prevalence of heart failure (HF) owing to the ageing population, identification of modifiable risk factors is important. In a mouse model, chronic hypohydration induced by lifelong ...water restriction promotes cardiac fibrosis. Hypohydration elevates serum sodium. Here, we evaluate the association of serum sodium at middle age as a measure of hydration habits with risk to develop HF.
We analysed data from Atherosclerosis Risk in Communities study with middle age enrolment (45-66 years) and 25 years of follow-up. Participants without water balance dysregulation were selected: serum sodium within normal range (135-146 mmol/L), not diabetic, not obese and free of HF at baseline (N = 11 814). In time-to-event analysis, HF risk was increased by 39% if middle age serum sodium exceeded 143 mmol/L corresponding to 1% body weight water deficit hazard ratio 1.39, 95% confidence interval (CI) 1.14-1.70. In a retrospective case-control analysis performed on 70- to 90-year-old attendees of Visit 5 (N = 4961), serum sodium of 142.5-143 mmol/L was associated with 62% increase in odds of left ventricular hypertrophy (LVH) diagnosis odds ratio (OR) 1.62, 95% CI 1.03-2.55. Serum sodium above 143 mmol/L was associated with 107% increase in odds of LVH (OR 2.07, 95% CI 1.30-3.28) and 54% increase in odds of HF (OR 1.54, 95% CI 1.06-2.23). As a result, prevalence of HF and LVH was increased among 70- to 90-year-old participants with higher middle age serum sodium.
Middle age serum sodium above 142 mmol is a risk factor for LVH and HF. Maintaining good hydration throughout life may slow down decline in cardiac function and decrease prevalence of HF.
Machine learning may be useful to characterize cardiovascular risk, predict outcomes, and identify biomarkers in population studies.
To test the ability of random survival forests, a machine learning ...technique, to predict 6 cardiovascular outcomes in comparison to standard cardiovascular risk scores.
We included participants from the MESA (Multi-Ethnic Study of Atherosclerosis). Baseline measurements were used to predict cardiovascular outcomes over 12 years of follow-up. MESA was designed to study progression of subclinical disease to cardiovascular events where participants were initially free of cardiovascular disease. All 6814 participants from MESA, aged 45 to 84 years, from 4 ethnicities, and 6 centers across the United States were included. Seven-hundred thirty-five variables from imaging and noninvasive tests, questionnaires, and biomarker panels were obtained. We used the random survival forests technique to identify the top-20 predictors of each outcome. Imaging, electrocardiography, and serum biomarkers featured heavily on the top-20 lists as opposed to traditional cardiovascular risk factors. Age was the most important predictor for all-cause mortality. Fasting glucose levels and carotid ultrasonography measures were important predictors of stroke. Coronary Artery Calcium score was the most important predictor of coronary heart disease and all atherosclerotic cardiovascular disease combined outcomes. Left ventricular structure and function and cardiac troponin-T were among the top predictors for incident heart failure. Creatinine, age, and ankle-brachial index were among the top predictors of atrial fibrillation. TNF-α (tissue necrosis factor-α) and IL (interleukin)-2 soluble receptors and NT-proBNP (N-Terminal Pro-B-Type Natriuretic Peptide) levels were important across all outcomes. The random survival forests technique performed better than established risk scores with increased prediction accuracy (decreased Brier score by 10%-25%).
Machine learning in conjunction with deep phenotyping improves prediction accuracy in cardiovascular event prediction in an initially asymptomatic population. These methods may lead to greater insights on subclinical disease markers without apriori assumptions of causality.
URL: http://www.clinicaltrials.gov. Unique identifier: NCT00005487.
Incident cardiovascular disease (CVD) increases with increasing low-density lipoprotein cholesterol (LDL-C) concentration and exposure duration. Area under the LDL-C versus age curve is a possible ...risk parameter. Data-based demonstration of this metric is unavailable and whether the time course of area accumulation modulates risk is unknown.
Using CARDIA (Coronary Artery Risk Development in Young Adults) study data, we assessed the relationship of area under LDL-C versus age curve to incident CVD event risk and modulation of risk by time course of area accumulation—whether risk increase for the same area increment is different at different ages.
This prospective study included 4,958 asymptomatic adults age 18 to 30 years enrolled from 1985 to 1986. The outcome was a composite of nonfatal coronary heart disease, stroke, transient ischemic attack, heart failure hospitalization, cardiac revascularization, peripheral arterial disease intervention, or cardiovascular death.
During a median 16-year follow-up after age 40 years, 275 participants had an incident CVD event. After adjustment for sex, race, and traditional risk factors, both area under LDL-C versus age curve and time course of area accumulation (slope of LDL-C curve) were significantly associated with CVD event risk (hazard ratio: 1.053; p < 0.0001 per 100 mg/dl × years; hazard ratio: 0.797 per mg/dl/year; p = 0.045, respectively).
Incident CVD event risk depends on cumulative prior exposure to LDL-C and, independently, time course of area accumulation. The same area accumulated at a younger age, compared with older age, resulted in a greater risk increase, emphasizing the importance of optimal LDL-C control starting early in life.
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In the past 30 years, several organizations, such as the US Association for the Advancement of Medical Instrumentation (AAMI), the British Hypertension Society, the European Society of Hypertension ...(ESH) Working Group on Blood Pressure (BP) Monitoring, and the International Organization for Standardization (ISO), have developed protocols for clinical validation of BP measuring devices. However, it is recognized that science, as well as patients, consumers, and manufacturers, would be best served if all BP measuring devices were assessed for accuracy according to an agreed single validation protocol that had global acceptance. Therefore, an international initiative was taken by the AAMI, ESH, and ISO experts who agreed to develop a universal standard for device validation. This statement presents the key aspects of a validation procedure, which were agreed by the AAMI, ESH, and ISO representatives as the basis for a single universal validation protocol. As soon as the AAMI/ESH/ISO standard is fully developed, this will be regarded as the single universal standard and will replace all other previous standards/protocols.
In severe acquired aplastic anemia, hematopoietic failure is the result of immune-mediated destruction of bone marrow stem and progenitor cells. Immunosuppressive therapy with antithymocyte globulin ...(ATG) plus cyclosporine is an effective alternative to stem-cell transplantation and improves blood counts and survival. Although horse ATG is the standard therapy, rabbit ATG is more potent in depleting peripheral-blood lymphocytes and is preferred in other clinical circumstances.
From December 2005 through July 2010, we performed a randomized trial comparing these two ATG formulations in conventional regimens. Patients were treated at a single facility. The primary outcome was hematologic response at 6 months, as determined by blood counts. The study was designed to enroll 60 patients each for the rabbit-ATG and horse-ATG groups and was powered to detect a difference of 25 percentage points in the response rate.
A large, unexpected difference was observed in the rate of hematologic response at 6 months in favor of horse ATG (68%; 95% confidence interval CI, 56 to 80) as compared with rabbit ATG (37%; 95% CI, 24 to 49; P<0.001). Overall survival at 3 years also differed, with a survival rate of 96% (95% CI, 90 to 100) in the horse-ATG group as compared with 76% (95% CI, 61 to 95) in the rabbit-ATG group (P=0.04) when data were censored at the time of stem-cell transplantation, and 94% (95% CI, 88 to 100) as compared with 70% (95% CI, 56 to 86; P=0.008) in the respective groups when stem-cell-transplantation events were not censored.
In a randomized study, rabbit ATG was inferior to horse ATG as a first treatment for severe aplastic anemia, as indicated by hematologic response and survival. (Funded by the Intramural Research Program of the National Institutes of Health; ClinicalTrials.gov number, NCT00260689.).
Patients with severe aplastic anemia (SAA) are either treated with bone marrow transplant (BMT) or immunosuppression (IST) depending on their age, comorbidities, and available donors. In 2017, our ...phase 2 trial reported improved hematologic responses with the addition of eltrombopag (EPAG) to standard IST for SAA when compared with a historical cohort treated with IST alone. However, the rates and characteristics of long-term complications, relapse, and clonal evolution, previously described in patients treated with IST alone, are not yet known with this new regimen, IST and EPAG. Patients were accrued from 2012 to 2020, with a total of 178 subjects included in this secondary endpoint analysis. With double the sample size and a much longer median follow-up (4 years) since the original publication in 2017, we report a cumulative relapse rate of 39% in responding patients who received cyclosporine (CSA) maintenance and clonal evolution of 15% in all treated patients at 4 years. Relapse occurred at distinct timepoints: after CSA dose reduction and EPAG discontinuation at 6 months, and after 2 years when CSA was discontinued. Most relapsed patients were retreated with therapeutic doses of CSA +/- EPAG, and two-thirds responded. Clonal evolution to a myeloid malignancy or chromosome 7 abnormality (high-risk) was noted in 5.7% of patients and conferred a poorer overall survival. Neither relapse nor high-risk evolution occurred at a higher rate than was observed in a historical comparator cohort, but the median time to both events was earlier in IST and EPAG treated patients. This trial was registered at www.clinicaltrials.gov as #NCT01623167.
Pretreatment blood counts, particularly an absolute reticulocyte count ≥25×109/L, correlate with response to immunosuppressive therapy in severe aplastic anemia. In recent trials, eltrombopag ...combined with standard immunosuppressive therapy yielded superior responses than those to immunosuppressive therapy alone. Our single institution retrospective study aimed to elucidate whether historical predictors of response to immunosuppressive therapy alone were also associated with response to immunosuppressive therapy plus eltrombopag. We sought correlations of blood counts, thrombopoietin levels and the presence of paroxysmal nocturnal hemoglobinuria clones with both overall and complete responses in 416 patients with severe aplastic anemia, aged 2-82 years (median, 30 years), initially treated with immunosuppressive therapy plus eltrombopag between 2012 and 2019 (n=176) or with immunosuppressive therapy alone between 1999 and 2010 (n=240). Compared to non-responders, patients in the group of overall responders to immunosuppressive therapy plus eltrombopag had significantly higher pretreatment absolute reticulocyte counts, higher neutrophil counts and reduced thrombopoietin levels, as also observed for the group treated with immunosuppressive therapy alone. Addition of eltrombopag markedly improved the overall response in subjects with an absolute reticulocyte count between 10-30×109/L from 60% (54 of 90) to 91% (62 of 68). Absolute lymphocyte count correlated with complete response in the groups treated with immunosuppressive therapy with or without eltrombopag, especially in adolescents aged ≥10 years and adults, but the correlation was reversed in younger children. Platelet count and the presence of a paroxysmal nocturnal hemoglobinuria clone did not correlate with responses to immunosuppressive therapy. Blood counts remain the best predictors of response to nontransplant therapies in severe aplastic anemia. Addition of eltrombopag to immunosuppressive therapy shifted patients with a lower absolute reticulocyte count into a better prognostic category.
Analysis of hematopoietic stem cell function in nonhuman primates provides insights that are relevant for human biology and therapeutic strategies. In this study, we applied quantitative genetic ...barcoding to track the clonal output of transplanted autologous rhesus macaque hematopoietic stem and progenitor cells over a time period of up to 9.5 months. We found that unilineage short-term progenitors reconstituted myeloid and lymphoid lineages at 1 month but were supplanted over time by multilineage clones, initially myeloid restricted, then myeloid-B clones, and then stable myeloid-B-T multilineage, long-term repopulating clones. Surprisingly, reconstitution of the natural killer (NK) cell lineage, and particularly the major CD16+/CD56− peripheral blood NK compartment, showed limited clonal overlap with T, B, or myeloid lineages, and therefore appears to be ontologically distinct. Thus, in addition to providing insights into clonal behavior over time, our analysis suggests an unexpected paradigm for the relationship between NK cells and other hematopoietic lineages in primates.
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•The output of individual primate HSPCs can be clonally tracked in vivo•Unilineage, bilineage, and multilineage clones can be mapped posttransplantation•Primate myeloid and B cells are more closely related than B and T cells•The dominant blood fraction of NK cells forms a unique hematopoietic lineage
Quantitative tracking of rhesus macaque hematopoiesis at a single-cell level by genetic cellular barcoding highlights a distinct origin for the dominant peripheral blood natural killer cell lineage.
Immune aplastic anemia (AA) features somatic loss of HLA class I allele expression on bone marrow cells, consistent with a mechanism of escape from T-cell-mediated destruction of hematopoietic stem ...and progenitor cells. The clinical significance of HLA abnormalities has not been well characterized. We examined the somatic loss of HLA class I alleles and correlated HLA loss and mutation-associated HLA genotypes with clinical presentation and outcomes after immunosuppressive therapy in 544 AA patients. HLA class I allele loss was detected in 92 (22%) of the 412 patients tested, in whom there were 393 somatic HLA gene mutations and 40 instances of loss of heterozygosity. Most frequently affected was HLA-B*14:02, followed by HLA-A*02:01, HLA-B*40:02, HLA-B*08:01, and HLA-B*07:02. HLA-B*14:02, HLA-B*40:02, and HLA-B*07:02 were also overrepresented in AA. High-risk clonal evolution was correlated with HLA loss, HLA-B*14:02 genotype, and older age, which yielded a valid prediction model. In 2 patients, we traced monosomy 7 clonal evolution from preexisting clones harboring somatic mutations in HLA-A*02:01 and HLA-B*40:02. Loss of HLA-B*40:02 correlated with higher blood counts. HLA-B*07:02 and HLA-B*40:01 genotypes and their loss correlated with late-onset of AA. Our results suggest the presence of specific immune mechanisms of molecular pathogenesis with clinical implications. HLA genotyping and screening for HLA loss may be of value in the management of immune AA. This study was registered at clinicaltrials.gov as NCT00001964, NCT00061360, NCT00195624, NCT00260689, NCT00944749, NCT01193283, and NCT01623167.
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