Site-directed mutagenesis of HLA molecules reveals the functional epitope of a human HLA-A1/A36-specific monoclonal antibody.

Eplet 44KM is currently listed in the HLA Epitope Registry but does not adhere to the eplet definition of an amino acid configuration within a 3.5 Å radius. Eplet 44KM has been previously redefined to the antibody-verified reactivity pattern 44K/150V/158V, based on reactivity analysis of monoclonal antibody VDK1D12. Since the three residues are always simultaneously present on common HLA alleles, methods to define which residue is crucial for antibody-induction and binding are limited. In this proof-of-concept study, we performed site-directed mutagenesis to narrow down the antibody-verified reactivity pattern 44K/150V/158V to a single amino acid and defined 44K as the eplet or functional epitope of mAb VDK1D12.

Prevalence of major electrocardiographic abnormalities in patients with hypertension in a primary care clinic in Hong Kong.

BACKGROUND: Hypertension is strongly associated with cardiovascular events. Studies have shown that electrocardiographic (ECG) abnormalities were associated with increased risks for cardiovascular events. However local data is limited. The objectives of this study were: (1) to determine the prevalence of major electrocardiographic abnormalities in patients with hypertension in primary care in Hong Kong, and (2) to determine the association of major electrocardiographic abnormalities with patients' socio-economical background, cardiovascular disease and cardiovascular risk factors. METHODS: This was a cross-sectional study. Subjects were hypertensive patients aged between 18 and 80 who were enrolled in the Risk Assessment and Management Programme (RAMP) in a general outpatient clinic in Hong Kong. Outcome measures were prevalence of probable ischaemic heart disease (IHD), complete left bundle branch block (LBBB), left ventricular hypertrophy (LVH) and atrial fibrillation (AF) in patients with hypertension. The Pearson Chi-square test, independent t-test and Mantel-Haenszel test were used to measure the association between socioeconomic characteristics and cardiovascular risk factors, and ECG abnormalities. RESULTS: 504 hypertensive patients aged 18-80 were recruited in a general outpatient clinic. 6.3% had probable IHD, 0.4% had complete LBBB, 4.0% had LVH and 1.0% had AF. Probable IHD was associated with smoking (P = 0.032), hypercholesterolaemia (P = 0.037) and higher 10-year CV risk (P = 0.04). Complete LBBB was associated with smoking (P = 0.021) and hypercholesterolaemia (P = 0.022). LVH was associated with male gender (P = 0.001) and longer duration of hypertension (P = 0.035). AF was not significantly associated with any of the clinical or sociodemographic parameters. CONCLUSIONS: This study showed that a significant proportion of patients with hypertension at the primary care setting in Hong Kong had probable ischaemic heart disease, left ventricular hypertrophy and atrial fibrillation. This finding is consistent with both overseas data and historic data in Hong Kong. The detection of electrocardiographic abnormalities is helpful in hypertension management by improving risk stratification.

A Tale of 3 Asian Cities: How is Primary Care Responding to COVID-19 in Hong Kong, Singapore, and Beijing.

Hong Kong, Singapore, and Beijing have some of the highest numbers of international arrivals and densest living spaces globally, yet these cities have reported low numbers of deaths amid the coronavirus disease 2019 (COVID-19) outbreak. Primary care has played different roles in each of the health systems in combatting the pandemic. Both Hong Kong and Singapore have a 2-tiered health system with the majority of primary care provided in the private sector. The primary care system in Beijing consists of community health facilities, township health centers, and village clinics. The role of primary care in Hong Kong includes using the public primary care clinics as part of an enhanced surveillance program together with accident and emergency departments, as well as triaging patients with suspected infection to hospitals. Singapore's response to COVID-19 has included close cooperation between redeveloped polyclinics and private and public health preparedness clinics to provide screening with swab tests for suspected cases in the primary care setting. Beijing's unique response has consisted of using online platforms for general practitioners to facilitate monitoring among community residents, as well as public health education and a mobilized pharmacy refill program to reduce risk of transmission. Established challenges, however, include shortages of personal protective equipment and the heavy workload for health care staff. Regardless, all 3 cities have demonstrated enhanced preparedness since experiencing the severe acute respiratory syndrome epidemic, and the responses of their primary care systems therefore may offer learning points for other countries during the COVID-19 pandemic.

The Manchester Respiratory Activities of Daily Living Questionnaire: Reliability and Validity of the Chinese Version with Pictorial Enhancement.

BACKGROUND: The Manchester Respiratory Activities of Daily Living Questionnaire (MRADLQ) is a valid and reliable tool measuring the functional level of patients with COPD in multidimensional aspects. However, a local validation of the questionnaire is lacking in Hong Kong. OBJECTIVE: To develop a Chinese version of MRADLQ with pictorial enhancement (C-MRADLQ) and study its reliability and validity. PATIENTS AND METHODS: A total of 238 patients suffering from COPD were recruited from nine public hospitals and five Nurse and Allied Health Respiratory Clinics by convenient sampling. A total of 64 patients with normal spirometry results and no previous clinical diagnosis of COPD were invited to complete the C-MRADLQ for comparison and examination of its validity. Ten out of 302 patients were re-assessed with the C-MRADLQ after one week by the same rater for test-retest reliability. The C-MRADLQ was correlated with spirometry result, COPD classifications and groups by Global Initiative for Chronic Obstructive Lung Disease (GOLD), the modified Medical Research Council Dyspnea Scale (mMRC Dyspnea Scale), COPD Assessment Test (CAT), Chinese Version of the Shortness of Breath Questionnaire (C-SOBQ), number of admission and the ADO index. RESULTS: The C-MRADLQ shows good test-retest reliability as indicated by an intra-class correlation coefficient value of 0.975. It is significantly correlated with COPD stage, COPD group, SOBQ score, CAT score, mMRC, ADO index, spirometry results, and number of admissions. The SOBQ score, number of admissions, FEV1/FVC, and COPD group could significantly predict the total C-MRADLQ score. A total of 67.9% of participants' mMRC levels were correctly classified by using the C-MRADLQ total score. The agreement of the original and new versions of questions 20 and 21 of C-MRADLQ was 97.3% and 90.1%, respectively. CONCLUSION: The pictorial version of the C-MRADLQ is a validated and reliable functional assessment tool to measure functional status among patients with COPD in the Chinese population.

Prediction models and nomograms for 10-year risk of end-stage renal disease in Chinese type 2 diabetes mellitus patients in primary care.

AIMS: To develop and validate 10-year risk prediction models, nomograms and charts for end-stage renal disease (ESRD) in Chinese patients with type 2 diabetes mellitus (T2DM) in primary care, in order to guide individualized treatment. MATERIALS AND METHODS: This was a 10-year population-based observational cohort study. A total of 141 516 Chinese T2DM patients without history of cardiovascular disease or ESRD who were managed in public primary care clinics in 2008 were included and followed up until December 2017. Two-thirds of these patients were randomly selected to develop sex-specific ESRD risk prediction models using Cox regressions. The validity and accuracy of the models were tested on the remaining third of patients using Harrell's C-index. We selected variables based on their clinical and statistical importance to construct the nomograms and charts. RESULTS: The median follow-up period was 9.75 years. The cumulative incidence of ESRD was 6.0% (men: 6.1%, women: 5.9%). Age, diabetes duration, systolic blood pressure (SBP), SBP variability, diastolic blood pressure, triglycerides, glycated haemoglobin (HbA1c), HbA1c variability, urine albumin to creatinine ratio (UACR), and estimated glomerular filtration rate (eGFR) were significant predictors for both sexes. Smoking and total cholesterol to HDL cholesterol ratio were additional significant predictors for men and women, respectively. The models showed Harrell's C-statistics of 0.889/0.889 (women/men). Age, eGFR, UACR, SBP and HbA1c were selected for both sexes to develop nomograms and charts. CONCLUSIONS: Using routinely available variables, the 10-year ESRD risk of Chinese T2DM patients in primary care can be predicted with approximately 90% accuracy. We have developed different tools to facilitate routine ESRD risk prediction in primary care, so that individualized care can be provided to prevent or delay ESRD in T2DM patients.

Bi-functional IgG-lysosomal enzyme fusion proteins for brain drug delivery.

Most lysosomal storage disorders affect the central nervous system. However, lysosomal enzymes do not cross the blood-brain barrier (BBB), and intravenous enzyme infusion is not effective for the brain. Lysosomal enzymes can be re-engineered for BBB transport as IgG-enzyme fusion proteins, where the IgG domain is a monoclonal antibody (MAb) against an endogenous BBB receptor/transporter, and which acts as a molecular Trojan horse to deliver the enzyme to brain. However, the problem is retention of high enzyme activity following enzyme fusion to the IgG. The present investigation shows this is possible with a versatile approach that employs fusion of the enzyme to either the IgG heavy chain or light chain using a long flexible linker. The model IgG is a chimeric monoclonal antibody (MAb) against the human insulin receptor (HIR). The enzyme activity of the HIRMAb-enzyme fusion protein is preserved for hexosaminidase A, which is mutated in Tay Sachs disease, for protein palmitoylthioesterase-1, which is mutated in Batten disease type 1, acid sphingomyelinase, which is mutated in Niemann Pick disease type A, and beta galactosidase-1, which is mutated in GM1 gangliosidosis.

Association between educational level and cardiovascular disease and all-cause mortality in patients with type 2 diabetes: a prospective study in the Joint Asia Diabetes Evaluation Program.

PURPOSE: The aim of this study was to describe the association between educational level and incident cardiovascular disease (CVD) and all-cause mortality in Hong Kong Chinese patients with type 2 diabetes. PATIENTS AND METHODS: We included 12,634 patients with type 2 diabetes who were enrolled into the Joint Asia Diabetes Evaluation Program between June 1, 2007, and June 30, 2017. We classified patients' educational level into the following three groups: ≤6 years, 6-13 years, and >13 years. Incident CVD events were identified using hospital discharge diagnoses. Death was identified from Hong Kong Death Register. We estimated HRs for incident CVD and all-cause mortality using Cox regression models. RESULTS: Patients with the highest educational level were younger and had shorter diabetes duration and better glycemic control at enrollment than those with the lowest educational level. During the median follow-up of 6.2 years for CVD and 6.4 years for all-cause mortality, 954 CVD events and 833 deaths were recorded. HRs for CVD and all-cause mortality were 0.73 (95% CI: 0.57, 0.94) and 0.71 (95% CI: 0.54, 0.94) for the highest educational level compared to the lowest educational level, after adjustment for age, sex, diabetes duration, and family history of diabetes. CONCLUSION: Educational level is inversely associated with the risk of CVD and all-cause mortality among Hong Kong Chinese patients with type 2 diabetes. Hong Kong Chinese patients with type 2 diabetes and low educational level should be given special attention for the prevention of key complications of diabetes.

Ten-year risk prediction models of complications and mortality of Chinese patients with diabetes mellitus in primary care in Hong Kong: a study protocol.

INTRODUCTION: Diabetes mellitus (DM) is a major disease burden worldwide because it is associated with disabling and lethal complications. DM complication risk assessment and stratification is key to cost-effective management and tertiary prevention for patients with diabetes in primary care. Existing risk prediction functions were found to be inaccurate in Chinese patients with diabetes in primary care. This study aims to develop 10-year risk prediction models for total cardiovascular diseases (CVD) and all-cause mortality among Chinese patients with DM in primary care. METHODS AND ANALYSIS: A 10-year cohort study on a population-based primary care cohort of Chinese patients with diabetes, who were receiving care in the Hospital Authority General Outpatient Clinic on or before 1 January 2008, were identified from the clinical management system database of the Hospital Authority. All patients with complete baseline risk factors will be included and followed from 1 January 2008 to 31 December 2017 for the development and validation of prediction models. The analyses will be carried out separately for men and women. Two-thirds of subjects will be randomly selected as the training sample for model development. Cox regressions will be used to develop 10-year risk prediction models of total CVD and all-cause mortality. The validity of models will be tested on the remaining one-third of subjects by Harrell's C-statistics and calibration plot. Risk prediction models for diabetic complications specific to Chinese patients in primary care will enable accurate risk stratification, prioritisation of resources and more cost-effective interventions for patients with DM in primary care. ETHICS AND DISSEMINATION: The study was approved by the Institutional Review Board of the University of Hong Kong-the Hospital Authority Hong Kong West Cluster (reference number: UW 15-258). TRIAL REGISTRATION NUMBER: NCT03299010; Pre-results.

Blood-Brain Barrier Transport, Plasma Pharmacokinetics, and Neuropathology Following Chronic Treatment of the Rhesus Monkey with a Brain Penetrating Humanized Monoclonal Antibody Against the Human Transferrin Receptor.

A monoclonal antibody (mAb) against the blood-brain barrier (BBB) transferrin receptor (TfR) is a potential agent for delivery of biologic drugs to the brain across the BBB. However, to date, no TfRMAb has been tested with chronic dosing in a primate model. A humanized TfRMAb against the human (h) TfR1, which cross reacts with the primate TfR, was genetically engineered with high affinity (ED50 = 0.18 ± 0.04 nM) for the human TfR type 1 (TfR1). For acute dosing, the hTfRMAb was tritiated and injected intravenously (IV) in the Rhesus monkey, which confirmed rapid delivery of the humanized hTfRMAb into both brain parenchyma, via transport across the BBB, and into cerebrospinal fluid (CSF), via transport across the choroid plexus. For chronic dosing, a total of 8 adult Rhesus monkeys (4 males, 4 females) were treated twice weekly for 4 weeks with 0, 3, 10, or 30 mg/kg of the humanized hTfRMAb via a 60 min IV infusion for a total of 8 doses prior to euthanasia and microscopic examination of brain and peripheral organs. A pharmacokinetics analysis showed the plasma clearance of the hTfRMAb in the primate was nonlinear, and plasma clearance was increased over 20-fold with chronic treatment of the low dose, 3 mg/kg, of the antibody. Chronic treatment of the primates with the 30 mg/kg dose caused anemia associated with suppressed blood reticulocytes. Immunohistochemistry of terminal brain tissue showed microglia activation, based on enhanced IBA1 immuno-staining, in conjunction with astrogliosis, based on increased GFAP immuno-staining. Moderate axonal/myelin degeneration was observed in the sciatic nerve. Further studies need to be conducted to determine if this neuropathology is induced by the antibody effector function, or is an intrinsic property of targeting the TfR in brain. The results indicate that chronic treatment of Rhesus monkeys with a humanized hTfRMAb may have a narrow therapeutic index, with associated toxicity related to microglial activation and astrogliosis of the brain.

Reduction in Brain Heparan Sulfate with Systemic Administration of an IgG Trojan Horse-Sulfamidase Fusion Protein in the Mucopolysaccharidosis Type IIIA Mouse.

Mucopolysaccharidosis Type IIIA (MPSIIIA), also known as Sanfilippo A syndrome, is an inherited neurodegenerative disease caused by mutations in the lysosomal enzyme, N-sulfoglucosamine sulfohydrolase (SGSH), also known as sulfamidase. Mutations in the SGSH enzyme, the only mammalian heparan N-sulfatase, cause accumulation of lysosomal inclusion bodies in brain cells comprising heparan sulfate (HS) glycosaminoglycans (GAGs). Treatment of MPSIIIA with intravenous recombinant SGSH is not possible because this large molecule does not cross the blood-brain barrier (BBB). BBB penetration by SGSH was enabled in the present study by re-engineering this enzyme as an IgG-SGSH fusion protein, where the IgG domain is a chimeric monoclonal antibody (mAb) against the mouse transferrin receptor (TfR), designated the cTfRMAb. The IgG domain of the fusion protein acts as a molecular Trojan horse to deliver the enzyme into brain via transport on the endogenous BBB TfR. The cTfRMAb-SGSH fusion protein bound to the mouse TfR with high affinity, ED50 = 0.74 ± 0.07 nM, and retained high SGSH enzyme activity, 10 043 ± 1003 units/mg protein, which is comparable to recombinant human SGSH. Male and female MPSIIIA mice, null for the SGSH enzyme, were treated for 6 weeks with thrice-weekly intraperitoneal injections of vehicle, 5 mg/kg of the cTfRMAb alone, or 5 mg/kg of the cTfRMAb-SGSH fusion protein, starting at the age of 2 weeks, and were euthanized 1 week after the last injection. Brain and liver HS, as determined by liquid chromatography-mass spectrometry, were elevated 30-fold and 36-fold, respectively, in the MPSIIIA mouse. Treatment of the mice with the cTfRMAb-SGSH fusion protein caused a 70% and 85% reduction in brain and liver HS, respectively. The reduction in brain HS was associated with a 28% increase in latency on the rotarod test of motor activity in male mice. The mice exhibited no injection related reactions, and only a low titer end of study antidrug antibody response was observed. In conclusion, substantial reductions in brain pathologic GAGs in a murine model of MPSIIIA are produced by chronic systemic administration of an IgG-SGSH fusion protein engineered to penetrate the BBB via receptor-mediated transport.

How and Why Preclerkship Students Set Learning Goals and Assess Their Achievement: A Qualitative Exploration.

PURPOSE: Health professionals are expected to routinely assess their weaknesses, set learning goals, and monitor their achievement. Unfortunately, it is well known that these professionals often struggle with effectively integrating external data and self-perceptions. To know how best to intervene, it is critical that the health professionals community understand the cues students and practitioners use to assess their abilities. Here the authors aimed to gain insights into how and why medical students set learning goals, monitor their progress, and demonstrate their learning. METHOD: In 2012, the authors conducted semistructured interviews with Year 2 students (n = 20), applying an inductive approach to data analysis by iteratively developing, refining, and testing coding structures. RESULTS: Themes were constructed through discussion and consensus: (1) Students were diverse in how they set learning goals, (2) they used a range of approaches to monitor their progress, and (3) they struggled to balance studying for exams with preparation for clinical training. Tensions observed highlight assumptions embedded in medical curricula that can be problematic. CONCLUSIONS: Educators often treat medical students as a cohesive whole, thereby creating a mismatch between assessments that are intended to be formative and information students use to monitor their progress. Despite limited exposure to clinical contexts, goal generation and monitoring often stem from a desire to prepare for clinical practice. In grappling with these tensions, it is important to be mindful that students are individualistic in how they balance their commitment to prepare for clinical work and the need to concentrate on exams.

Declining Trends of Cardiovascular-Renal Complications and Mortality in Type 2 Diabetes: The Hong Kong Diabetes Database.

OBJECTIVE: Nationwide studies on secular trends of diabetes complications are not available in Asia. We examined changes in risk factor control and incidence of complications from diabetes and death in a large longitudinal cohort of Chinese adults with type 2 diabetes in Hong Kong. RESEARCH DESIGN AND METHODS: Between 1 January 2000 and 31 December 2012, 338,908 Chinese adults with type 2 diabetes underwent metabolic and complication assessment in 16 diabetes centers operated by Hong Kong Hospital Authority that provided care to a large majority of diagnosed patients. Patients were followed for incident acute myocardial infarction (AMI), stroke, end-stage renal disease (ESRD), and death until 31 December 2012. Risk factor levels between enrollment periods were compared. Incidence of clinical events, stratified by diabetes duration, was examined over time. RESULTS: Incidence of complications from diabetes and death declined over the observation period in patients at varying disease duration. Among the high-risk group with diabetes for at least 15 years, crude incidence of AMI decreased from 8.7 to 5.8, stroke from 13.5 to 10.1, ESRD from 25.8 to 22.5, and death from 29.0 to 26.6 per 1,000 person-year between the periods 2000 to 2002 and 2010 to 2012. Improvements in levels of metabolic risk factors were detected. Proportion of patients achieving HbA1c <7.0% (53 mmol/mol) was increased from 32.9 to 50.0%, blood pressure ≤130/80 mmHg from 24.7 to 30.7%, and LDL cholesterol <2.6 mmol/L from 25.8 to 38.1%. CONCLUSIONS: From this territory-wide Hong Kong Diabetes Database, we observed decreases in incidence of cardiovascular-renal complications and death and corresponding improvements in risk factor control over a 13-year period.

Very High Plasma Concentrations of a Monoclonal Antibody against the Human Insulin Receptor Are Produced by Subcutaneous Injection in the Rhesus Monkey.

Brain penetration of recombinant protein drugs is possible following the re-engineering of the drug as an IgG fusion protein. The IgG domain is a monoclonal antibody (mAb) against an endogenous blood-brain barrier (BBB) receptor transporter, such as the insulin receptor. One such mAb targets the human insulin receptor (HIR) and is active in Rhesus monkeys. Prior work has measured the plasma pharmacokinetics of HIRMAb-derived fusion proteins following intravenous (IV) infusion. However, an alternative method of administration for chronic treatment of brain disease is the subcutaneous (SQ) route. The extent to which an antibody against the insulin receptor undergoes systemic distribution and clearance is unknown. Therefore, in the present study, the rate of plasma clearance of the HIRMAb is measured in Rhesus monkeys following IV or SQ administration of 3, 10, and 30 mg/kg doses of the antibody. The HIRMAb is readily absorbed into the systemic circulation following SQ injection with a 42% plasma bioavailability. The rate of plasma clearance of the antibody, 0.04-0.06 mL/min/kg, is the same following either IV or SQ administration. Owing to the slow rate of plasma clearance of the antibody, high concentrations of the HIRMAb are sustained in plasma for days after the SQ injection. The plasma concentration of the HIRMAb exceeds 0.8 mg/mL, which is 9% of the entire plasma IgG pool in the primate, after the SQ injection of the high dose, 30 mg/kg, of the antibody. In summary, the pharmacokinetics of plasma clearance of the HIRMAb are such that HIRMAb-derived fusion proteins can be developed as protein therapeutics for the brain with chronic SQ administration on a weekly or twice-weekly regimen.

Insulin Receptor Antibody-α-N-Acetylglucosaminidase Fusion Protein Penetrates the Primate Blood-Brain Barrier and Reduces Glycosoaminoglycans in Sanfilippo Type B Fibroblasts.

Mucopolysaccharidosis Type IIIB (MPSIIIB) is caused by mutations in the gene encoding the lysosomal enzyme, α-N-acetylglucosaminidase (NAGLU). MPSIIIB presents with severe disease of the central nervous system, but intravenous NAGLU enzyme replacement therapy has not been developed because the NAGLU enzyme does not cross the blood-brain barrier (BBB). A BBB-penetrating form of the enzyme was produced by re-engineering NAGLU as an IgG-enzyme fusion protein, where the IgG domain is a monoclonal antibody (mAb) against the human insulin receptor (HIR). The HIRMAb traverses the BBB via transport on the endogenous insulin receptor and acts as a molecular Trojan horse to ferry the fused NAGLU across the BBB from blood. The NAGLU was fused to the carboxyl terminus of each heavy chain of the HIRMAb via an extended 31-amino acid linker, and the fusion protein is designated HIRMAb-LL-NAGLU. The fusion protein retains high affinity binding to the HIR, and on a molar basis has an enzyme activity equal to that of recombinant human NAGLU. Treatment of MPSIIIB fibroblasts with the fusion protein normalizes intracellular NAGLU enzyme activity and reduces sulfate incorporation into intracellular glycosoaminoglycan. The fusion protein is targeted to the lysosomal compartment of the cells as shown by confocal microscopy. The fusion protein was radiolabeled with the [(125)I]-Bolton-Hunter reagent and injected intravenously in the adult Rhesus monkey. The fusion protein was rapidly cleared from plasma by all major peripheral organs. The high brain uptake of the fusion protein, 1% injected dose/brain, enables normalization of brain NAGLU enzyme activity with a therapeutic dose of 1 mg/kg. The HIRMAb-LL-NAGLU fusion protein is a new treatment of the brain in MPSIIIB, which can be administered by noninvasive intravenous infusion.

Association between the 8-item Morisky medication adherence scale (MMAS-8) score and glycaemic control among Chinese diabetes patients.

Adherence with oral hypoglycaemic agent is crucial to achieve optimal glycaemic control. The 8-item Morisky Medication Adherence Scale (MMAS-8) has been frequently used, yet the association between MMAS-8 score and glycaemic control among Chinese diabetes patients is largely unknown. Two general out-patient clinics were randomly selected in a district with socio-demographic characteristics representative of the entire Hong Kong population. A consecutive sample of adult type-2 diabetes patients currently taking oral hypoglycaemic agents was included. The glycaemic control was reflected by the level of hemoglobin A1c (HbA1c) taken within the previous 6 months. Factors associated with poor glycaemic control (HbA1c ≥ 7.0%) were evaluated by linear regression analysis. From 565 eligible Chinese patients with an average age of 63.2 years (SD 9.7) and male proportion of 46.5%, the average HbA1c was 7.1% (SD 1.1%), and 52.0% had poor glycaemic control. The proportion of poor medication adherence (MMAS-8 ≤ 6) was 32.2%. After controlling for socio-demographics, lifestyle, medication use, and health characteristics, the MMAS-8 score was correlated with better glycaemic control (beta -0.095; 95%CI -0.164 to -0.026, P = .007). The MMAS-8 score had a weak and negative correlation with HbA1c level. The instrument should be applied with caution when predicting glycaemic control in clinical practice.

Insulin receptor antibody-sulfamidase fusion protein penetrates the primate blood-brain barrier and reduces glycosoaminoglycans in Sanfilippo type A cells.

Mutations in the lysosomal enzyme, N-sulfoglucosamine sulfohydrolase (SGSH), also called sulfamidase, cause accumulation of lysosomal inclusion bodies in the brain of children born with mucopolysaccharidosis type IIIA, also called Sanfilippo type A syndrome. Enzyme replacement therapy with recombinant SGSH does not treat the brain because the enzyme is a large molecule drug that does not cross the blood-brain barrier (BBB). A BBB-penetrating form of SGSH was produced by re-engineering the enzyme as an IgG fusion protein, where the IgG domain is a monoclonal antibody (mAb) against the human insulin receptor (HIR). The HIRMAb domain of the HIRMAb-SGSH fusion protein acts as a molecular Trojan horse to ferry the fused enzyme across the BBB. The HIRMAb-SGSH was produced in stably transfected host cells and purified to homogeneity by protein A chromatography. The fusion protein reacted with antibodies against either human IgG or SGSH on Western blotting. High affinity binding to the HIR was retained following SGSH fusion to the HIRMAb, with an EC50 of 0.33 ± 0.05 nM in an HIR binding ELISA. The SGSH enzyme activity of the HIRMAb-SGSH fusion protein was 4712 ± 388 units/mg protein based on a two-step fluorometric enzyme assay. The HIRMAb-SGSH was taken up by lysosomes in MPSIIIA fibroblasts, and treatment of these cells with the fusion protein caused an 83% reduction in sulfate incorporation into lysosomal glycosoaminoglycans. The HIRMAb-SGSH fusion protein was radiolabeled with the [(125)I]-Bolton-Hunter reagent and injected intravenously in the Rhesus monkey. The brain uptake of the fusion protein was high, ∼1% injected dose/brain. Calculations, based on this level of brain uptake, suggest normalization of brain SGSH enzyme activity is possible following administration of therapeutic doses of the fusion protein. These studies describe a novel IgG-SGSH fusion protein that is a new noninvasive treatment of the brain in MPS type IIIA.

Insulin receptor antibody-iduronate 2-sulfatase fusion protein: pharmacokinetics, anti-drug antibody, and safety pharmacology in Rhesus monkeys.

Mucopolysaccharidosis (MPS) Type II is caused by mutations in the gene encoding the lysosomal enzyme, iduronate 2-sulfatase (IDS). The majority of MPSII cases affect the brain. However, enzyme replacement therapy with recombinant IDS does not treat the brain, because IDS is a large molecule drug that does not cross the blood-brain barrier (BBB). To enable BBB penetration, IDS has been re-engineered as an IgG-IDS fusion protein, where the IgG domain is a monoclonal antibody (MAb) against the human insulin receptor (HIR). The HIRMAb crosses the BBB via receptor-mediated transport on the endogenous BBB insulin receptor, and the HIRMAb domain of the fusion protein acts as a molecular Trojan horse to ferry the fused IDS into brain from blood. The present study reports on the first safety pharmacology and pharmacokinetics study of the HIRMAb-IDS fusion protein. Juvenile male Rhesus monkeys were infused intravenously (IV) weekly for 26 weeks with 0, 3, 10, or 30 mg/kg of the HIRMAb-IDS fusion protein. The plasma clearance of the fusion protein followed a linear pharmacokinetics profile, which was equivalent either with measurements of the plasma concentration of immunoreactive HIRMAb-IDS fusion protein, or with assays of plasma IDS enzyme activity. Anti-drug antibody (ADA) titers were monitored monthly, and the ADA response was primarily directed against the variable region of the HIRMAb domain of the fusion protein. No infusion related reactions or clinical signs of immune response were observed during the course of the study. A battery of safety pharmacology, clinical chemistry, and tissue histopathology showed no signs of adverse events, and demonstrate the safety profile of chronic treatment of primates with 3-30 mg/kg weekly IV infusion doses of the HIRMAb-IDS fusion protein.

Prevalence of complications among Chinese diabetic patients in urban primary care clinics: a cross-sectional study.

BACKGROUND: A territory-wide diabetes management program (Risk Assessment Management Program - RAMP) was recently established, providing comprehensive management for all diabetics, helping to delineate current level of control and complications prevalence among primary care diabetic patients in Hong Kong. METHOD: This cross-sectional study captured anonymous clinical data from RAMP patients. Data obtained include sociodemographic details, type of diabetes, illness duration, family history, drug usage, coexisting illnesses, diabetic complications and other clinical parameters. RESULTS: Data from 15,856 type 2 diabetic patients were analyzed. 57.1% were above 60 years old, with mean disease duration of 7.3 years. Hypertension was the commonest coexisting chronic illness (57.6%). 30.2% and 61.8% have their systolic and diastolic pressure controlled to below 130 mmHg and 80 mmHg respectively. Over half (51.5%) had an HbA1c level of less than 7.0%. 88.4% did not achieve target lipid level. 15% were on diet control alone. Only 22.2% were on statins. In patients with microalbuminuria and macroalbuminuria, 40.7% and 54.5% were on angiotensin converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) respectively. 12.9%, 38.8% and 2.4% had diabetic retinopathy, nephropathy and neuropathy respectively. Overall, 37.9%, 7.3% and 0.4% had single, two and three concurrent microvascular complications respectively. CONCLUSION: The level of diabetic control is comparable with other developed countries. We demonstrated a high prevalence of microvascular complications among Chinese primary care patients despite achieving adequate HbA1c levels, highlighting the importance of managing all aspects of diabetes including weight, lipid and blood pressure. Efforts to improve holistic management must be tailored according to the needs of our population, with the challenges that the majority have low educational background and in the older age group.

Blood-brain barrier molecular trojan horse enables imaging of brain uptake of radioiodinated recombinant protein in the rhesus monkey.

Recombinant proteins are large molecule drugs that do not cross the blood-brain barrier (BBB). However, BBB-penetration of protein therapeutics is enabled by re-engineering the recombinant protein as IgG fusion proteins. The IgG domain is a monoclonal antibody (mAb) against an endogenous BBB receptor-mediated transport system, such as the human insulin receptor (HIR), and acts as a molecular Trojan horse to ferry the fused protein across the BBB. In the present study, a recombinant lysosomal enzyme, iduronate 2-sulfatase (IDS), is fused to the HIRMAb, and BBB penetration of the IDS alone vs the HIRMAb-IDS fusion protein is compared in the Rhesus monkey. Recombinant IDS and the HIRMAb-IDS fusion protein were radiolabeled with indirect iodination with the [(125)I]-Bolton-Hunter reagent and with direct iodination with Iodogen/[(125)I]-idodine. IDS and the HIRMAb-IDS fusion protein have comparable plasma pharmacokinetics and uptake by peripheral organs. IDS does not cross the BBB. The HIRMAb-IDS fusion protein crosses the BBB and the brain uptake is 1% of injected dose/brain. Brain imaging shows HIRMAb-IDS penetration to all parts of brain, and immunoprecipitation of brain radioactivity shows intact fusion protein in brain. The use of BBB molecular Trojan horses enables brain imaging of recombinant proteins that are re-engineered for BBB transport.

Disaggregation of amyloid plaque in brain of Alzheimer's disease transgenic mice with daily subcutaneous administration of a tetravalent bispecific antibody that targets the transferrin receptor and the Abeta amyloid peptide.

Anti-amyloid antibodies (AAA) are under development as new therapeutics that disaggregate the amyloid plaque in brain in Alzheimer's disease (AD). However, the AAAs are large molecule drugs that do not cross the blood-brain barrier (BBB), in the absence of BBB disruption. In the present study, an AAA was re-engineered for receptor-mediated transport across the BBB via the endogenous BBB transferrin receptor (TfR). A single chain Fv (ScFv) antibody form of an AAA was fused to the carboxyl terminus of each heavy chain of a chimeric monoclonal antibody (mAb) against the mouse TfR, and this produced a tetravalent bispecific antibody designated the cTfRMAb-ScFv fusion protein. Unlike a conventional AAA, which has a plasma half-time of weeks, the cTfRMAb-ScFv fusion protein is cleared from plasma in mice with a mean residence time of about 3 h. Therefore, a novel protocol was developed for the treatment of one year old presenilin (PS)-1/amyloid precursor protein (APP) AD double transgenic PSAPP mice, which were administered daily subcutaneous (sc) injections of 5 mg/kg of the cTfRMAb-ScFv fusion protein for 12 consecutive weeks. At the end of the treatment, brain amyloid plaques were quantified with confocal microscopy using both Thioflavin-S staining and immunostaining with the 6E10 antibody against Abeta amyloid fibrils. Fusion protein treatment caused a 57% and 61% reduction in amyloid plaque in the cortex and hippocampus, respectively. No increase in plasma immunoreactive Abeta amyloid peptide, and no cerebral microhemorrhage, was observed. Chronic daily sc treatment of the mice with the fusion protein caused no immune reactions and only a low titer antidrug antibody response. In conclusion, re-engineering AAAs for receptor-mediated BBB transport allows for reduction in brain amyloid plaque without cerebral microhemorrhage following daily sc treatment for 12 weeks.