Clinical characteristics and outcomes of thrombotic microangiopathy in Malaysia

Yee Yee Yap,Jameela Sathar,Kian Boon Law,Putri Astina Binti Zulkurnain,Syed Carlo Edmund,Kian Meng Chang,Ross Baker 대한혈액학회 2018 Blood Research Vol.53 No.2

Background Thrombotic microangiopathy (TMA) with non-deficient ADAMTS-13 (a disintegrin-like and metalloprotease with thrombospondin type 1 motif 13) outcome is unknown hence the survival analysis correlating with ADAMTS-13 activity is conducted in Malaysia/ Methods This was a retrospective epidemiological study involving all cases of TMA from 2012‒2016. Results We evaluated 243 patients with a median age of 34.2 years; 57.6% were female. Majority of the patients were Malay (62.5%), followed by Chinese (23.5%) and Indian (8.6%). The proportion of patients with thrombotic thrombocytopenic purpura (TTP) was 20.9%, 72.2% of which were acquired while 27.8% were congenital. Patients with ADAMTS-13 activity ≥5% had a four-fold higher odds of mortality compared to those with ADAMTS-13 activity <5% (odds ratio: 4.133, P=0.0425). The mortality rate was 22.6% (N=55). Most cases had secondary etiologies (42.5%), followed by acquired TTP (16.6%), atypical hemolytic uremic syndrome (HUS) or HUS (12.8%) and congenital TTP (6.4%). Patients with secondary TMA had inferior overall survival (P=0.0387). The secondary causes comprised systemic lupus erythematosus (30%), infection (29%), pregnancy (10%), transplant (8%), malignancy (6%), and drugs (3%). Transplant-associated TMA had the worst OS (P=0.0016) among the secondary causes. Plasma exchange, methyl-prednisolone and intravenous immunoglobulin were recorded as first-line treatments in 162 patients, while rituximab, bortezomib, vincristine, azathioprine, cyclo-phosphamide, cyclosporine, and tacrolimus were described in 78 patients as second-line treatment. Conclusion This study showed that TMA without ADAMTS-13 deficiency yielded inferior outcomes compared to TMA with severeADAMTS-13 deficiency, although this difference was not statistically significant.

Clinical characteristics and outcomes of thrombotic microangiopathy in Malaysia

Yee Yee Yap,Jameela Sathar,Kian Boon Law,Putri Astina Binti Zulkurnain,Syed Carlo Edmund,Kian Meng Chang,Ross Baker 대한혈액학회 2018 Blood Research Vol.53 No.2

Background Thrombotic microangiopathy (TMA) with non-deficient ADAMTS-13 (a disintegrin-like and metalloprotease with thrombospondin type 1 motif 13) outcome is unknown hence the survival analysis correlating with ADAMTS-13 activity is conducted in Malaysia/ Methods This was a retrospective epidemiological study involving all cases of TMA from 2012‒2016. Results We evaluated 243 patients with a median age of 34.2 years; 57.6% were female. Majority of the patients were Malay (62.5%), followed by Chinese (23.5%) and Indian (8.6%). The proportion of patients with thrombotic thrombocytopenic purpura (TTP) was 20.9%, 72.2% of which were acquired while 27.8% were congenital. Patients with ADAMTS-13 activity ≥5% had a four-fold higher odds of mortality compared to those with ADAMTS-13 activity <5% (odds ratio: 4.133, P=0.0425). The mortality rate was 22.6% (N=55). Most cases had secondary etiologies (42.5%), followed by acquired TTP (16.6%), atypical hemolytic uremic syndrome (HUS) or HUS (12.8%) and congenital TTP (6.4%). Patients with secondary TMA had inferior overall survival (P=0.0387). The secondary causes comprised systemic lupus erythematosus (30%), infection (29%), pregnancy (10%), transplant (8%), malignancy (6%), and drugs (3%). Transplant-associated TMA had the worst OS (P=0.0016) among the secondary causes. Plasma exchange, methyl-prednisolone and intravenous immunoglobulin were recorded as first-line treatments in 162 patients, while rituximab, bortezomib, vincristine, azathioprine, cyclo-phosphamide, cyclosporine, and tacrolimus were described in 78 patients as second-line treatment. Conclusion This study showed that TMA without ADAMTS-13 deficiency yielded inferior outcomes compared to TMA with severeADAMTS-13 deficiency, although this difference was not statistically significant.

Use of glecaprevir/pibrentasvir in patients with chronic hepatitis C virus infection and severe renal impairment

Desmond Y. H. Yap,Kevin S. H. Liu,Yu-Chun Hsu,Grace L. H. Wong,Ming-Chang Tsai,Chien-Hung Chen,Ching-Sheng Hsu,Yee Tak Hui,Michael K. K. Li,Chen-Hua Liu,Yee-Man Kan,Ming-Lung Yu,Man-Fung Yuen 대한간학회 2020 Clinical and Molecular Hepatology(대한간학회지) Vol.26 No.4

Background/Aims: Data on treatment efficacy and safety of glecaprevir/pibrentasvir (GLE/PIB) for chronic hepatitis C virus (HCV) infection in Asian patients with severe renal impairment are limited. This study aimed to study the treatment and side effects of GLE/PIB in these patients infected with non-1 genotype (GT) HCV. Methods: We prospectively recruited patients with Child’s A cirrhosis and eGFR <30 mL/min/1.73 m2 in Hong Kong and Taiwan during 2017–2018 to receive GLE/PIB treatment. Results: Twenty-one patients (GT2, n=7; GT3, n=6; and GT6, n=8) received GLE/PIB for 11.2±1.8 weeks. All except one were treatment-naïve. GLE/PIB was initiated in 16 patients while on dialysis (seven on peritoneal dialysis [PD] and nine on hemodialysis) and in five patients before dialysis. One patient died of PD-related peritonitis during treatment and two were lost to follow up. The SVR12 rate in the remaining 18 patients was 100%. All patients achieved undetectable levels at 4-, 12-, 24- and 48-week after treatment. Patients with deranged alanine aminotransferase showed normalization after 4 weeks and the response was sustained for 48 weeks. No significant adverse event was observed. Conclusions: GLE/PIB treatment was associated with high efficacy and tolerability in HCV-infected patients with severe renal impairment.

The Wound Healing Potential of Lignosus rhinocerus and Other Ethno-myco Wound Healing Agents

Hui-Yeng Y. Yap,Mohammad Farhan Ariffeen Rosli,Soon-Hao Tan,Boon-Hong Kong,Shin-Yee Fung 한국균학회 2023 Mycobiology Vol.51 No.1

Wound care has become increasingly important over the years. Various synthetic products for wound care treatment have been reported to cause toxic side effects and therefore nat- ural products are in significant demand as they have minimal side effects. The presence of bioactive compounds in medicinal mushrooms contributes to various biological activities which assist in the early inflammatory phase, keratinocyte proliferation, and its migration enhancement which are pertinent to wound rehabilitation. Lignosus rhinocerus (tiger milk mushroom) can reduce the inflammation phase in wound healing by fighting off bacterial infection and modulating pro-inflammatory cytokines expression in the early stage to avoid prolonged inflammation and tissue damage. The antibacterial, immunomodulating, and anti- inflammatory activities exhibited by most macrofungi play a key role in enhancing wound healing. Several antibacterial and antifungal compounds sourced from traditional botanicals/- products may prevent further complications and reoccurrence of injury to a wounded site. Scientific studies are actively underway to ascertain the potential use of macrofungi as a wound healing agent.

Numerical and experimental studies of mixed-host organic light emitting diodes

Riku Chowdhury,Teng-Sian Ong,Yeh-Yee Kee,Seong-Shan Yap,Teck-Yong Tou 한국물리학회 2015 Current Applied Physics Vol.15 No.11

Electrical characteristic and luminance of three mixed-host organic light emitting diodes (OLEDs): namely the uniformly mixed, step-wise graded and mixed, and continuously graded and mixed, were compared with the conventional hetero-junction OLED in both numerical and experimental studies. These mixed-host OLEDs were fabricated by a mixed-source thermal evaporation process, and half-cell devices were also fabricated to provide some input parameters for OLED simulations. The current efficiencies were largely influenced by their device structures and strongly agreed with the computed current balance factors. The improved mixed-host OLED performances can be discussed with aid from simulations, which include spatial distributions of electron and hole, carrier mobility, electric field profiles, the total recombination rates in the light emitting layer.

Investigation of Lithium Transference Number in PMMA Composite Polymer Electrolytes Using Monte Carlo (MC) Simulation and Recurrence Relation

Koh, Renwei Eric,Sun, Cha Chee,Yap, Yee Ling,Cheang, Pei Ling,You, Ah Heng The Korean Electrochemical Society 2021 Journal of electrochemical science and technology Vol.12 No.2

In this study, Monte Carlo (MC) simulation is conducted with recurrence relation to study the effect of SiO₂ with different particle size and their roles in enhancing the ionic conductivity and lithium transference number of PMMA composite polymer electrolytes (CPEs). The MC simulated ionic conductivity is verified with the measurements from Electrochemical Impedance Spectroscopy (EIS). Then, the lithium transference number of CPEs is calculated using recurrence relation with the MC simulated current density and the reference transference number obtained. Incorporation of micron-size SiO₂ (≤10 ㎛) fillers into the mixture improves the ionic conductivity from 8.60×10^-5 S/cm to 2.35×10^-4 S/cm. The improvement is also observed on the lithium transference number, where it increases from 0.088 to 0.3757. Furthermore, the addition of nano-sized SiO₂ (≤12 nm) fillers further increases the ionic conductivity up towards 3.79×10^-4 S/cm and lithium transference number of 0.4105. The large effective surface area of SiO₂ fillers is responsible for the improvement in ionic conductivity and the transference number in PMMA composite polymer electrolytes.

Coronary Intravascular Lithotripsy Versus Rotational Atherectomy in an Asian Population: Clinical Outcomes in Real-World Patients

Khung Keong Yeo,Jie Jun Wong,Sridharan Umapathy,Yann Shan Keh,Yee How Lau,Jonathan Yap,Muhammad Idu,Chee Yang Chin,Jiang Ming Fam,Boon Wah Liew,Chee Tang Chin,Philip En Hou Wong,Tian Hai Koh 대한심장학회 2022 Korean Circulation Journal Vol.52 No.4

Background and Objectives: We compared real-world clinical outcomes of patients receiving intravascular lithotripsy (IVL) versus rotational atherectomy (RA) for heavily calcified coronary lesions. Methods: Fifty-three patients who received IVL from January 2017 to July 2020 were retrospectively compared to 271 patients who received RA from January 2017 to December 2018. Primary endpoints were in-hospital and 30-day major adverse cardiovascular events (MACE). Results: IVL patients had a higher prevalence of acute coronary syndrome (56.6% vs 24.4, p<0.001), multivessel disease (96.2% vs 73.3%, p<0.001) and emergency procedures (17.0% vs 2.2%, p<0.001) compared to RA. In-hospital MACE (11.3% vs 5.9%, p=0.152), MI (7.5% vs 3.3%, p=0.152), and mortality (5.7% vs 3.0%, p=0.319) were not statistically significant. 30-day MACE was higher in the IVL cohort vs RA (17.0% vs 7.4%, p=0.035). Propensity score adjusted regression using IVL was also performed on in-hospital MACE (odds ratio [OR], 1.677; 95% confidence interval [CI], 0.588–4.779) and 30-day MACE (OR, 1.910; 95% CI, 0.774–4.718). Conclusions: These findings represent our initial IVL experience in a high-risk, real-world cohort. Although the event rate in the IVL arm was numerically higher compared to RA, the small numbers and retrospective nature of this study preclude definitive conclusions. These clinical outcomes are likely to improve with greater experience and better case selection, allowing IVL to effectively treat complex calcified coronary lesions.

Validating lactate dehydrogenase (LDH) as a component of the PLASMIC predictive tool (PLASMIC-LDH)

Christopher Chin Keong Liam,Jim Yu-Hsiang Tiao,Yee Yee Yap,Yi Lin Lee,Jameela Sathar,Simon McRae,Amanda Davis,Jennifer Curnow,Robert Bird,Philip Choi,Pantep Angchaisuksiri,Sim Leng Tien,Joyce Ching Me 대한혈액학회 2023 Blood Research Vol.58 No.1

Background The PLASMIC score is a convenient tool for predicting ADAMTS13 activity of <10%. Lactate dehydrogenase (LDH) is widely used as a marker of haemolysis in thrombotic thrombocytopenic purpura (TTP) monitoring, and could be used as a replacement marker for lysis. We aimed to validate the PLASMIC score in a multi-centre Asia Pacific region, and to explore whether LDH could be used as a replacement marker for lysis. Methods Records of patients with thrombotic microangiopathy (TMA) were reviewed. Patients’ ADAMTS13 activity levels were obtained, along with clinical/laboratory findings relevant to the PLASMIC score. Both PLASMIC scores and PLASMIC-LDH scores, in which LDH replaced traditional lysis markers, were calculated. We generated a receiver operator characteristics (ROC) curve and compared the area under the curve values (AUC) to determine the predictive ability of each score. Results 46 patients fulfilled the inclusion criteria, of which 34 had ADAMTS13 activity levels of <10%. When the patients were divided into intermediate-to-high risk (scores 5‒7) and low risk (scores 0‒4), the PLASMIC score showed a sensitivity of 97.1% and specificity of 58.3%, with a positive predictive value (PPV) of 86.8% and negative predictive value (NPV) of 87.5%. The PLASMIC-LDH score had a sensitivity of 97.1% and specificity of 33.3%, with a PPV of 80.5% and NPV of 80.0%. Conclusion Our study validated the utility of the PLASMIC score, and demonstrated PLASMIC-LDH as a reasonable alternative in the absence of traditional lysis markers, to help identify high-risk patients for treatment via plasma exchange.