Revisit of Optimal Donor Number Estimation in the Hong Kong Bone Marrow Donor Registry.

High resolution typing of the HLA-DPB1 locus for patient who requested for hematopoietic stem cell transplantation (HSCT) workup has recently become mandatory by the National Marrow Donor Program (NMDP) in order to facilitate matching between donors and recipients for better outcomes. The likelihood of identifying HLA matched donors in Hong Kong, on top of the existing HLA-A, -B, -C, and -DRB1 loci, is revisited in this study. HLA-A, -B, -C, -DRB1 and -DPB1 genotypes of 5,266 volunteer unrelated Chinese donors from the Hong Kong Bone Marrow Donor Registry (HKBMDR), were included in this study. Matching models were employed to determine the matching probabilities for 10/10(DPB1) and 9/10(DPB1) HLA match. The matching probabilities are 20% at 10/10(DPB1) HLA match and 55% at 9/10(DPB1) match, based on the existing 130,000 donors in the HKBMDR. The likelihoods of match become 27% and 65% respectively, by increasing the registry to 250,000. However, if DPB T-cell-epitope (TCE) model is considered in the matching, the probability will increase to 46% at 10/10 DPB1 permissive mismatching. Our findings provide vital information about the future planning on the targeted recruitment size, HLA typing and search strategies of the donor registry and arose the transplant physicians' acceptability to 9/10(DBP1) or 10/10(DBP1) HLA match. Nevertheless, the marrow donor registry has planned for increasing the registry size and bringing down the age of recruited donors which will ultimately enhance patient outcome.

Effect of CPAP on cardiovascular events in minimally symptomatic OSA: long-term follow-up of the MOSAIC randomised controlled trial.

The effect of continuous positive airway pressure (CPAP) on cardiovascular events is uncertain in minimally symptomatic obstructive sleep apnoea. Previous 2-year follow-up data from the Multicentre Obstructive Sleep Apnoea Intervention Cardiovascular (MOSAIC) trial showed a marginal reduction in cardiovascular events with CPAP therapy. We now present long-term MOSAIC study follow-up data. Median (first quartile, third quartile) follow-up was 5.0 (2.2, 5.0) and 3.7 (1.5, 5.0) years for CPAP and standard care, respectively. Compared to standard care, CPAP had no statistically significant effect on the risk of cardiovascular events (HR=0.83, p=0.54, 95% CI 0.46-1.51).

Establishing Simultaneous T Cell Receptor Excision Circles (TREC) and K-Deleting Recombination Excision Circles (KREC) Quantification Assays and Laboratory Reference Intervals in Healthy Individuals of Different Age Groups in Hong Kong.

The clinical experience gathered throughout the years has raised awareness of primary immunodeficiency diseases (PIDD). T cell receptor excision circles (TREC) and kappa-deleting recombination excision circles (KREC) assays for thymic and bone marrow outputs measurement have been widely implemented in newborn screening (NBS) programs for Severe Combined Immunodeficiency. The potential applications of combined TREC and KREC assay in PIDD diagnosis and immune reconstitution monitoring in non-neonatal patients have been suggested. Given that ethnicity, gender, and age can contribute to variations in immunity, defining the reference intervals of TREC and KREC levels in the local population is crucial for setting up cut-offs for PIDD diagnosis. In this retrospective study, 479 healthy Chinese sibling donors (240 males and 239 females; age range: 1 month-74 years) from Hong Kong were tested for TREC and KREC levels using a simultaneous quantitative real-time PCR assay. Age-specific 5th-95th percentile reference intervals of TREC and KREC levels (expressed in copies per µL blood and copies per 106 cells) were established in both pediatric and adult age groups. Significant inverse correlations between age and both TREC and KREC levels were observed in the pediatric age group. A significant higher KREC level was observed in females than males after 9-12 years of age but not for TREC. Low TREC or KREC levels were detected in patients diagnosed with mild or severe PIDD. This assay with the established local reference intervals would allow accurate diagnosis of PIDD, and potentially monitoring immune reconstitution following haematopoietic stem cell transplantation or highly active anti-retroviral therapy in the future.

Novel coronavirus (COVID-19) infection: What a doctor on the frontline needs to know.

Coronavirus disease 2019 (COVID-19) is a zoonotic respiratory infection originating from Wuhan, China. Rapidly spreading from Wuhan to all inhabited continents of the world, the World Health Organisation declared COVID-19 a pandemic on March 11, 2019. Infected patients present with fever and cough; radiological features include bilateral infiltrates on chest x-ray and computed tomography scanning. Management is supportive with oxygen supplementation, broad-spectrum antibiotics as well as careful fluid balancing. A number of drugs, both new and old, are currently in clinical trials and being used on an experimental basis in clinical practice. The COVID-19 pandemic is the greatest worldwide public health crisis of a generation, and has led to seismic political, economic and social changes. This review provides an overview of COVID-19 for junior doctors who find themselves on a new frontline of healthcare.

Pulmonary hyalinising granuloma: a rare and elusive cause of multiple lung nodules.

A 72-year-old woman was referred with incidentally detected multiple lung nodules, one of which was identified as 18F-fluorodeoxyglucose (FDG)-avid on positron emission tomography. Extensive workup followed, including numerous radiographs, surveillance scans and a CT-guided biopsy which demonstrated chronic inflammation only. Following a wedge-resection, a diagnosis of pulmonary hyalinising granuloma (PHG) was made. PHG is a cause of FDG-avid single or multiple pulmonary nodules and can mimic lung cancer or metastatic disease radiologically. The diagnosis is often difficult to make with minimally invasive techniques such as needle-guided biopsies which do not tend to yield the diagnosis and requires surgical resection for definitive diagnosis and exclusion of malignancy.

Recurrent metastatic breast cancer presenting with portal hypertension and pseudocirrhosis.

We present a case of a 63-year-old woman with an acute history of abdominal distension and shortness of breath. She had no risk factors for liver disease though her prior medical history was positive for breast carcinoma, in remission for 14 years. Examination and investigations were initially consistent with decompensated cirrhosis, thought to be due to subclinical autoimmune hepatitis. Imaging revealed hepatic contour irregularity, atrophy of the liver parenchyma and numerous lesions highly suggestive for multifocal hepatocellular carcinoma. Surprisingly, tissue histology revealed no evidence of cirrhosis, but recurrence of breast cancer which had mimicked cirrhosis. Pseudocirrhosis may be indistinguishable from true cirrhosis without histopathology. It has previously been linked to chemotherapy-induced hepatic injury and nodular regenerative hyperplasia, although our case illustrates an uncommon pathophysiology. Pseudocirrhosis often represents a poor prognosis even with a good baseline performance status, and early involvement of palliative care specialists may be advisable.

Post pancreatitis/cholecystectomy gluten intolerance.

This case report describes the journey of a patient who suffered from life-limiting gastrointestinal symptoms after an acute bout of pancreatitis following ERCP for cholelithiasis bile following a ductal stone, and subsequent cholecystectomy. She was diagnosed and treated for IBS with medication without significant improvement. On implementation of a simple gluten and lactose exclusion diet she recovered to her premorbid state, and trials of gluten challenge triggered flares of symptoms. This case report will go on to discuss current evidence for use of gluten and lactose exclusion diets in some gluten sensitive patients misdiagnosed with IBS.

Rhinovirus infection in hospitalized children in Hong Kong: a prospective study.

OBJECTIVES: To analyze the clinical features and estimate the hospitalization disease burden of rhinovirus infection in children in Hong Kong. METHODS: In this prospective study, nasopharyngeal aspirates were taken from children aged <18 years with symptoms of acute respiratory infection admitted to Queen Mary Hospital on one fixed day of the week during August 2001-July 2002 for detection of common respiratory viruses by immunofluorescence, viral culture, and for rhinovirus, human metapneumovirus, and coronaviruses by reverse transcription polymerase chain reaction. The clinical features of rhinovirus infections were analyzed and hospitalization disease burden was estimated. RESULTS: Altogether 239 of the 426 nasopharyngeal aspirates (56.1%) were positive for respiratory viruses, including 151 patients with rhinovirus (35.4%). The median age was 2.34 years. Upper respiratory infection, asthma exacerbation, pneumonia, and acute bronchiolitis were diagnosed in 44.4%, 19.9%, 11.3%, and 7.9%, respectively. The most common symptoms were cough (81.5%), runny nose (76.8%), and fever (68.9%). Shortness of breath, wheezes, and crepitation were present in 25.8%, 29.1%, and 18.5%, respectively. Fifty-five of 99 patients (55.6%) had chest radiographic abnormalities, most commonly perihilar streakiness. Children with chronic diseases were more likely to have lower respiratory tract infection and these children required longer hospitalization (mean 0.6 days longer). Coinfection with other respiratory pathogens was common (33.1%). CONCLUSION: Rhinovirus is frequently associated with asthmatic exacerbations and lower respiratory tract infection, especially in children with chronic diseases and is potentially an important contributor to hospitalization in children in Hong Kong.