1.Development of a Non-Invasive Liver Fibrosis Score Based on Transient Elastography for Risk Stratification in Patients with Type 2 Diabetes
Chi-Ho LEE ; Wai-Kay SETO ; Kelly IEONG ; David T.W. LUI ; Carol H.Y. FONG ; Helen Y. WAN ; Wing-Sun CHOW ; Yu-Cho WOO ; Man-Fung YUEN ; Karen S.L. LAM
Endocrinology and Metabolism 2021;36(1):134-145
Background:
In non-alcoholic fatty liver disease (NAFLD), transient elastography (TE) is an accurate non-invasive method to identify patients at risk of advanced fibrosis (AF). We developed a diabetes-specific, non-invasive liver fibrosis score based on TE to facilitate AF risk stratification, especially for use in diabetes clinics where TE is not readily available.
Methods:
Seven hundred sixty-six adults with type 2 diabetes and NAFLD were recruited and randomly divided into a training set (n=534) for the development of diabetes fibrosis score (DFS), and a testing set (n=232) for internal validation. DFS identified patients with AF on TE, defined as liver stiffness (LS) ≥9.6 kPa, based on a clinical model comprising significant determinants of LS with the lowest Akaike information criteria. The performance of DFS was compared with conventional liver fibrosis scores (NFS, FIB-4, and APRI), using area under the receiver operating characteristic curve (AUROC), sensitivity, specificity, positive and negative predictive values (NPV).
Results:
DFS comprised body mass index, platelet, aspartate aminotransferase, high-density lipoprotein cholesterol, and albuminuria, five routine measurements in standard diabetes care. Derived low and high DFS cut-offs were 0.1 and 0.3, with 90% sensitivity and 90% specificity, respectively. Both cut-offs provided better NPVs of >90% than conventional fibrosis scores. The AUROC of DFS for AF on TE was also higher (P<0.01) than the conventional fibrosis scores, being 0.85 and 0.81 in the training and testing sets, respectively.
Conclusion
Compared to conventional fibrosis scores, DFS, with a high NPV, more accurately identified diabetes patients at-risk of AF, who need further evaluation by hepatologists.
2.Evaluation of commercial serological assays in Malaysia for detection of anti-Zika virus antibodies
Khoo, H.Y. ; Lee, H.Y. ; Khor, C.S. ; Tan, K.K. ; AbuBakar, S.
Tropical Biomedicine 2021;38(No.4):613-621
The recommended test guidelines for Zika virus (ZIKV) include using both molecular and
serological tools. While the molecular tools are useful for detecting acute infection, the
serological tools are useful for the detection of previous infections. Nevertheless, detection
of ZIKV-specific antibodies remains a challenge due to the high cross-reactivity between
ZIKV and other flaviviruses such as dengue virus (DENV) and Japanese encephalitis virus
(JEV). The objective of this study is to evaluate the commercially available enzyme-linked
immunosorbent assay (ELISA) for the detection of ZIKV IgG. In this study, we evaluated 6
commercially available anti-ZIKV IgG ELISA kits. Pre-characterized serum panels consisting
of 70 sera were selected for the evaluation. The diagnostic accuracy of each ELISA kits was
determined and compared to the gold standard, Foci Reduction Neutralization Test (FRNT).
The present study established that the performance of the NS1-based anti-ZIKV IgG ELISA kit
was superior to that which uses of the E protein as antigen. Overall, commercial ZIKV IgG
ELISA showed varying test performances, with some achieving moderate to high test
sensitivities and specificities. When compared against the FRNT, the test sensitivities ranged
from 7.1% to 78.6%, whereas, the test specificities ranged from 40.0% to 100%. Limitation to
the study includes the cross reactivity between flavivirus and specificity of the kit in
addressing the cross reactivity.
3.Lactic acid bacteria waste infusion as a source of attraction and oviposition stimulation of gravid female Aedes albopictus mosquitoes
Suria, M.M. ; Yap, P.C. ; Low, V.L. ; AbuBakar, S. ; Lee, H.Y.
Tropical Biomedicine 2022;39(No.4):499-503
The Plasmodium knowlesi secreted protein with an altered thrombospondin repeat (PkSPATR) is an
important protein that helps in the parasite’s invasion into the host cell. This protein has been regarded
as one of the potential vaccine candidates against P. knowlesi infection. This study investigates the
genetic diversity and natural selection of PkSPATR gene of P. knowlesi clinical isolates from Malaysia.
PCR amplification of the full length PkSPATR gene was performed on 60 blood samples of infected P.
knowlesi patients from Peninsular Malaysia and Malaysian Borneo. The amplified PCR products were
cloned and sequenced. Sequence analysis of PkSPATR from Malaysia showed higher nucleotide diversity
(CDS p: 0.01462) than previously reported Plasmodium vivax PvSPATR (p = 0.0003). PkSPATR from
Peninsular Malaysia was observed to have slightly higher diversity (CDS p: 0.01307) than those from
Malaysian Borneo (CDS p: 0.01212). Natural selection analysis on PkSPATR indicated significant purifying
selection. Multiple amino acid sequence alignment revealed 69 polymorphic sites. The phylogenetic
tree and haplotype network did not show any distinct clustering of PkSPATR. The low genetic diversity
level, natural selection and absence of clustering implied functional constrains of the PkSPATR protein.
4.Culturable pathogenic bacteria in ticks parasitizing farm animals and rodents in Malaysia
Loong, S.K. ; Lim, F.S. ; Khoo, J.J. ; Lee, H.Y. ; Suntharalingam, C. ; Ishak, S.N. ; Mohd-Taib, F.S. ; AbuBakar, S.
Tropical Biomedicine 2020;37(No.3):803-811
Ticks are vectors of bacteria, protozoa and viruses capable of causing serious and life threatening diseases in humans and animals. Disease transmission occurs through the transfer of pathogen from tick bites to susceptible humans or animals. Most commonly known tick-borne pathogens are obligate intracellular microorganisms but little is known on the prevalence of culturable pathogenic bacteria from ticks capable of growth on artificial nutrient media. One hundred and forty seven ticks originating from dairy cattle, goats and rodents were collected from nine selected sites in Peninsular Malaysia. The culture of surfacesterilized tick homogenates revealed the isolation of various pathogenic bacteria including, Staphylococcus sp., Corynebacterium sp., Rothia sp., Enterococcus faecalis, Klebsiella pneumoniae, Escherichia coli and Bacillus sp. and its derived genera. These pathogens are among those that affect humans and animals. Findings from this study suggest that in addition to the regular intracellular pathogens, ticks could also harbor extracellular pathogenic bacteria. Further studies, hence, would be needed to determine if these extracellular pathogens could contribute to human or animal infection.