There is much interest in the tissue of origin of circulating DNA in plasma. Data generated using DNA methylation markers have suggested that hematopoietic cells of white cell lineages are important ...contributors to the circulating DNA pool. However, it is not known whether cells of the erythroid lineage would also release DNA into the plasma.
Using high-resolution methylation profiles of erythroblasts and other tissue types, 3 genomic loci were found to be hypomethylated in erythroblasts but hypermethylated in other cell types. We developed digital PCR assays for measuring erythroid DNA using the differentially methylated region for each locus.
Based on the methylation marker in the ferrochelatase gene, erythroid DNA represented a median of 30.1% of the plasma DNA of healthy subjects. In subjects with anemia of different etiologies, quantitative analysis of circulating erythroid DNA could reflect the erythropoietic activity in the bone marrow. For patients with reduced erythropoietic activity, as exemplified by aplastic anemia, the percentage of circulating erythroid DNA was decreased. For patients with increased but ineffective erythropoiesis, as exemplified by β-thalassemia major, the percentage was increased. In addition, the plasma concentration of erythroid DNA was found to correlate with treatment response in aplastic anemia and iron deficiency anemia. Plasma DNA analysis using digital PCR assays targeting the other 2 differentially methylated regions showed similar findings.
Erythroid DNA is a hitherto unrecognized major component of the circulating DNA pool and is a noninvasive biomarker for differential diagnosis and monitoring of anemia.
The tourism industry is a major pillar of the economy of Hong Kong, and hospitality is an inseparable part. Front-line staff are of great importance for the hospitality industry, as their performance ...can largely affect the perception of a destination. Hence, the competencies of employees in the hospitality industry are critical. Although qualification frameworks (QFs) have been advocated in many different industries, a QF for hotels, particularly for front-line staff, is lacking. Thus, the present study aims to examine the core competencies required for front-office positions in hotels using Hong Kong, a popular tourism destination, as an example. Findings of the present study provide specific information to design an appropriate curriculum to fit the needs of the hospitality industry. Ultimately, the findings can serve as a reference for academic researchers and industry practitioners to facilitate the further development of a QF in the hospitality industry.
Hepatitis due to hepatitis B virus(HBV) reactivation can be severe and potentially fatal, but is preventable. HBV reactivation is most commonly reported in patients receiving cancer chemotherapy, ...especially rituximabcontaining therapy for hematological malignancies and those receiving stem cell transplantation. All patients with hematological malignancies receiving anticancer therapy should be screened for active or resolved HBV infection by blood tests for hepatitis B surface antigen(HBs Ag) and antibody to hepatitis B core antigen(antiHBc). Patients found to be positive for HBs Ag should be given prophylactic antiviral therapy to prevent HBV reactivation. For patients with resolved HBV infection, no standard strategy has yet been established to prevent HBV reactivation. There are usually two options. One is pre-emptive therapy guided by serial HBV DNA monitoring, whereby antiviral therapy is given as soon as HBV DNA becomes detectable. However, there is little evidence regarding the optimal interval and period of monitoring. An alternative approach is prophylactic antiviral therapy, especially for patients receiving highrisk therapy such as rituximab, newer generation of anti-CD20 monoclonal antibody, obinutuzumab or hematopoietic stem cell transplantation. This strategy may effectively prevent HBV reactivation and avoid the inconvenience of repeated HBV DNA monitoring. Entecavir or tenofovir are preferred over lamivudine as prophylactic therapy. Although there is no well-defined guideline on the optimal duration of prophylactic therapy, there is growing evidence to recommend continuing prophylactic antiviral therapy for at least 12 mo after cessation of chemotherapy, and even longer for those who receive rituximab or who had high serum HBV DNA levels before the start of immunosuppressive therapy. Many novel agents have recently become available for the treatment of hematological malignancies, and these agents may be associated with HBV reactivation. Although there is currently limited evidence to guide the optimal preventive measures, we recommend antiviral prophylaxis in HBs Ag-positive patients receiving novel treatments, especially the Bruton tyrosine kinase inhibitors and the phosphatidylinositol 3-kinase inhibitors, which are B-cell receptor signaling modulators and reduce proliferation of malignant B-cells. Further studies are needed to clarify the risk of HBV reactivation with these agents and the best prophylactic strategy in the era of targeted therapy for hematological malignancies.
Coronavirus disease 2019 (COVID-19) is affecting millions of patients worldwide. It is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which belongs to the family ...Coronaviridae, with 80% genomic similarities to SARS-CoV. Lymphopenia was commonly seen in infected patients and has a correlation to disease severity. Thrombocytopenia, coagulation abnormalities, and disseminated intravascular coagulation were observed in COVID-19 patients, especially those with critical illness and non-survivors. This pandemic has caused disruption in communities and hospital services, as well as straining blood product supply, affecting chemotherapy treatment and haematopoietic stem cell transplantation schedule. In this article, we review the haematological manifestations of the disease and its implication on the management of patients with haematological disorders.
Hyper-CVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone) has become a popular regimen for adults with acute lymphoblastic leukemia (ALL). We assessed the efficacy ...and tolerability of hyper-CVAD in the treatment of adult ALL.
We retrospectively reviewed ALL patients aged 18 or above receiving the hyper-CVAD regimen. We assessed complete remission rate and overall survival, as well as hepatitis B carrier rate and hepatitis flare due to hepatitis B virus (HBV) reactivation.
Fifty-two patients were treated with the hyper-CVAD regimen. The median age at diagnosis was 42 years; 27% of patients were Philadelphia (Ph) chromosome positive. The complete remission (CR) rate was 90.4% after the first cycle of chemotherapy. The induction mortality rate was 1.9%. Three patients required two cycles of hyper-CVAD to achieve CR. The median overall survival was 39.6 months and the 5-year overall survival was 50%. Age over 30 years and white blood cell count of more than 30 × 10
/l were found to be prognostic for poor overall survival in multivariate analysis. The hepatitis B carrier rate was 17% in our cohort, and the rate of hepatitis flare due to HBV reactivation was 11% in patients with current infection.
Hyper-CVAD is feasible and tolerable with a good CR rate in the treatment of adult ALL patients. It is an option for the treatment of ALL. Antiviral prophylaxis should be considered in ALL patients with HBV infection to reduce the risk of HBV reactivation.
Hong Kong is an intermediate tuberculosis (TB) burden region with a disease notification rate of 60.5 per 100 000 population in 2015. With the use of supervised treatment since 1970s and the use of ...drug susceptibility testing (DST) for guiding use of TB drugs for several decades 1, TB drug resistance rates in Hong Kong have declined and the multidrug-resistant (MDR)-TB rate has been kept at ∼1%. Successful control of MDR-TB was partly attributable to judicious use of ofloxacin and later levofloxacin in the 1990s 2, 3, the introduction of linezolid in the 2000s 4 among patients with fluoroquinolone-resistant MDR-TB or extensively drug-resistant (XDR)-TB, with intermittent dosing to enable its prolonged use 5, and selective use of delamanid among patients with complicated MDR-TB since 2012. To echo our support for using delamanid in the treatment of MDR-TB 6, 7, we would like to report our early experience in Hong Kong regarding the use of delamanid-containing regimens among patients with pre-XDR-TB (MDR-TB with bacillary resistance to either fluoroquinolone or second-line injectable agents) or XDR-TB.
Natural killer (NK)/T-cell lymphoma (NKTCL) is an aggressive malignancy with unique epidemiological, histological, molecular, and clinical characteristics. It occurs in two pathological forms, ...namely, extranodal NKTCL (ENKTCL) and aggressive NK leukemia, according to the latest World Health Organization (WHO) classification. Epstein-Barr virus (EBV) infection has long been proposed as the major etiology of lymphomagenesis. The adoption of high-throughput sequencing has allowed us to gain more insight into the molecular mechanisms of ENKTCL, which largely involve chromosome deletion and aberrations in Janus kinase (JAK)-signal transducer and activator of transcription (STAT), programmed cell death protein-1 (PD-1)/PD-ligand 1 (PD-L1) pathways, as well as mutations in tumor suppressor genes. The molecular findings could potentially influence the traditional chemoradiotherapy approach, which is known to be associated with significant toxicity. This article will review the latest molecular findings in NKTCL and recent advances in the field of molecular diagnosis in NKTCL. Issues of quality control and technical difficulties will also be discussed, along with future prospects in the molecular diagnosis and treatment of NKTCL.
Abstract
HKG is the first fully accessible variant database for Hong Kong Cantonese, constructed from 205 novel whole-exome sequencing data. There has long been a research gap in the understanding of ...the genetic architecture of southern Chinese subgroups, including Hong Kong Cantonese. HKG detected 196 325 high-quality variants with 5.93% being novel, and 25 472 variants were found to be unique in HKG compared to three Chinese populations sampled from 1000 Genomes (CHN). PCA illustrates the uniqueness of HKG in CHN, and the admixture study estimated the ancestral composition of HKG and CHN, with a gradient change from north to south, consistent with their geological distribution. ClinVar, CIViC and PharmGKB annotated 599 clinically significant variants and 360 putative loss-of-function variants, substantiating our understanding of population characteristics for future medical development. Among the novel variants, 96.57% were singleton and 6.85% were of high impact. With a good representation of Hong Kong Cantonese, we demonstrated better variant imputation using reference with the addition of HKG data, thus successfully filling the data gap in southern Chinese to facilitate the regional and global development of population genetics.
Intussusception is rarely reported in adult patients with acute leukemia. We report a case of intussusception in a 29-year-old woman with acute myeloid leukemia(AML). She developed right lower ...quadrant pain, fever, and vomiting on day 16 of induction chemotherapy.Physical examination showed tenderness and guarding at the right lower quadrant of the abdomen. Abdominal computed tomography(CT) showed distension of the cecum and ascending colon, which were filled with loops of small bowel, and herniation of the ileocecal valve into the cecum. We proceeded to laparotomy and revealed ileocecal intussusception with the ileocecal valve as the leading point. The terminal ileum was thickened and invaginated into the cecum, which showed gangrenous changes. Right hemicolectomy was performed and microscopic examination of the colonic tissue showed infiltration of leukemic cells. The patient recovered after the operation and was subsequently able to continue treatment for AML. This case demonstrates that the diagnosis of intussusception is difficult because the presenting symptoms can be non-specific, but abdominal CT can be informative for preoperative diagnosis. Resection of the involved bowel is recommended when malignancy is suspected or confirmed. Intussusception should be considered in any leukemia patients presenting with acute abdomen. A high index of clinical suspicion is important for early diagnosis.
Abstract The tissues of origin of plasma DNA can be revealed by methylation patterns. However, the relative DNA contributions from megakaryocytes and erythroblasts into plasma appeared inconsistent ...among studies. To shed light into this phenomenon, we developed droplet digital PCR (ddPCR) assays for the differential detection of contributions from these cell types in plasma based on megakaryocyte-specific and erythroblast-specific methylation markers. Megakaryocytic DNA and erythroid DNA contributed a median of 44.2% and 6.2% in healthy individuals, respectively. Patients with idiopathic thrombocytopenic purpura had a significantly higher proportion of megakaryocytic DNA in plasma compared to healthy controls (median: 59.9% versus 44.2%; P = 0.03). Similarly, patients with β-thalassemia were shown to have higher proportions of plasma erythroid DNA compared to healthy controls (median: 50.9% versus 6.2%) ( P < 0.0001). Hence, the concurrent analysis of megakaryocytic and erythroid lineage-specific markers could facilitate the dissection of their relative contributions and provide information on patients with hematological disorders.
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