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Wu J.-S.,Australian Neuromuscular Research Institute | Qiu W.,Australian Neuromuscular Research Institute | Qiu W.,Guangzhou University | Castley A.,PathWest Royal Perth Hospital | And 7 more authors.
Journal of the Neurological Sciences | Year: 2010

High-resolution HLA-DRB1 genotyping was performed in 97 OCB-positive and 68 OCB-negative cases with demyelinating disease to determine the influence of HLA-DRB1 alleles on the presence of OCB in a West Australian multiple sclerosis (MS) cohort. Carriage of the HLA-DRB1*1501 allele was associated with both OCB-positive and OCB-negative MS compared with controls, but more strongly with the OCB-positive group, and increased the likelihood of having OCB 2.1-fold with evidence of a dominant dose-effect. The HLA-DRB1*0301 allele was negatively correlated with OCB, with all homozygotes OCB-negative, suggesting a possible recessive protective effect of HLA-DRB1*0301. There was no significant correlation between OCB and the DRB1*04 alleles which have been associated with OCB-negative MS in previous Swedish and Japanese studies. Evidence of allelic interactions was found with HLA-DRB1*1501/*1301 heterozygotes having a reduced frequency of OCB and HLA-DRB1*0301/*0401 heterozygotes all being OCB-negative. These findings confirm the strong association between HLA-DRB1*1501 and OCB which has been found in other populations but indicate that the influence of other HLA-DRB1 alleles varies in different populations. Our study is the first to show that HLA-DRB1 allele interactions and dose-effects influence the frequency of OCB. © 2009 Elsevier B.V. All rights reserved.

Chaisri S.,Khon Kaen University | Kitcharoen K.,Khon Kaen University | Romphruk A.V.,Khon Kaen University | Romphruk A.,Khon Kaen University | And 3 more authors.
Immunogenetics | Year: 2013

Killer cell immunoglobulin-like receptors (KIRs) are cell surface receptors on natural killer (NK) cells and subsets of T cells. The functions of NK cells are partly regulated by interactions between KIRs and HLA ligands on target cells. In this study, the presence or absence of 17 KIR genes and their known HLA ligands have been investigated in 235 unrelated individuals living in northeastern Thailand (NET). Subtypes of KIR2DS4 including full length (KIR2DS4F) and deleted forms (KIR2DS4D) have also been determined. Framework genes (KIR2DL4, 3DL2, 3DL3, and 3DP1) were found in all individuals and KIR genes belonging to the A haplotype (KIR2DL1, 2DL3, 3DL1, and 2DS4) were present in more than 90 % of NET. KIR2DS4D (61.7 %) was more common than KIR2DS4F (52.8 %). A total of 33 different KIR genotypes were observed. Of these, three new genotypes were identified. The most common genotype (AA) was observed in 35.7 % of NET, and HLA-C alleles bearing the C1 epitope (HLA-C1) had the highest frequency (97 %). All individuals had at least one inhibitory KIR and its corresponding HLA ligand; 40.9 % of NET had three pairs of receptor-ligand combinations, and 18.3 % had all three receptor-ligand combinations of KIR2DL3+C1, 3DL1+Bw4, and 3DL2+A11. Surprisingly, the patterns of KIR gene frequencies in NET are more similar to those of Caucasians than Japanese, Korean, and Chinese. This is the first report on complete analysis of KIR and known HLA ligands in Thais. These data provide basic knowledge on KIR for further studies on disease associations and transplantation in northeastern Thais. © 2013 Springer-Verlag Berlin Heidelberg.

Glendenning P.,PathWest Royal Perth Hospital | Glendenning P.,University of Western Australia | Inderjeeth C.A.,University of Western Australia
Critical Reviews in Clinical Laboratory Sciences | Year: 2016

A dramatic and sustained surge in vitamin D test numbers has been attributed to the extraskeletal and probable intra/paracrine effects of vitamin D and not the important role of vitamin D in the regulation of extracellular calcium homeostasis and bone metabolism. This review summarizes recent data regarding the skeletal and extraskeletal effects of vitamin D, provides an overview of current methods of 25-hydroxyvitamin D measurement and includes the beneficial and adverse effects of vitamin D replacement. The role of 1,25-dihydroxyvitamin D, 24,25-dihydroxyvitamin D, vitamin D binding protein and free hormone levels are explored and potential future developments in this area are discussed. The adoption of a reference method for the measurement of 25-hydroxyvitamin D, certified reference standards and an independent certification program administered by the Centre of Disease Control is expected to improve routine analytical performance and is a major, crucial step forward. Improvements in accuracy, precision and sensitivity of 25-hydroxyvitamin D measurement is an important prelude to accurately defining the desirable level of 25-hydroxyvitamin D that is associated with the lowest risk for falls and fractures. Finally, the results of ongoing large, prospective, randomized clinical trials such as the Australian D-Health study should clarify the role of vitamin D supplementation in the prevention and management of skeletal and nonskeletal disorders, including vitamin D effects on mortality risk. © 2015 Taylor & Francis.

Lee M.K.V.,Royal Perth Hospital | Vasikaran S.,PathWest Royal Perth Hospital | Doery J.C.G.,Monash University | Wijeratne N.,Monash University | Prentice D.,Royal Perth Hospital
Postgraduate Medical Journal | Year: 2013

Introduction A standard short Synacthen test (SST) is the conventional diagnostic test for primary hypoadrenalism. Measuring simultaneous plasma cortisol and adrenocorticotrophin hormone (ACTH) and using the cortisol: ACTH ratio as a first-line test may be safer and more convenient than performing a SST. Methods A retrospective study of 349 patients who had a SST with simultaneous baseline plasma cortisol and ACTH performed between 2005 and 2010 in two separate Australian health centres. The plasma cortisol: ACTH ratio was calculated for each patient and their final diagnosis was determined based on their SST result and a review of their clinical notes. Results Eighteen patients had primary hypoadrenalism, 46 patients had secondary hypoadrenalism and 285 patients had normal adrenal function. All the patients with primary hypoadrenalism had a plasma cortisol: ACTH ratio <3, while none of the patients with normal adrenal function or secondary hypoadrenalism had a cortisol: ACTH ratio <3. Therefore, a cortisol: ACTH ratio <3 had a 100% sensitivity and specificity for the diagnosis of primary hypoadrenalism. Patients with secondary hypoadrenalism had a cortisol: ACTH ratio >3, while subjects with normal adrenal function had a cortisol: ACTH ratio >15. There was overlap in cortisol: ACTH ratios of patients with secondary hypoadrenalism and normal adrenal function. Conclusions Although the cortisol: ACTH ratio predicts primary hypoadrenalism, its value is limited to diagnosing primary hypoadrenalism as it does not distinguish secondary hypoadrenalism from normal adrenal function. Larger prospective studies that include patients with early primary hypoadrenalism are needed to confirm the reliability of plasma cortisol: ACTH ratio as a diagnostic test for primary hypoadrenalism.

Bell D.A.,University of Western Australia | Hooper A.J.,University of Western Australia | Edwards G.,St John of God Pathology | Southwell L.,University of Western Australia | And 5 more authors.
Atherosclerosis | Year: 2014

Objective: To determine whether a telephone call from a chemical pathologist to the requesting general practitioner (GP) of individuals at high risk of familial hypercholesterolaemia (FH) increases specialist referral and detection of FH. Method: Individuals with an LDL-cholesterol ≥6.5mmol/L without secondary causes were identified from a community laboratory; 100 cases and 96 historical controls. All laboratory reports (cases and controls) received interpretative comments highlighting FH. In addition, the cases' GPs received a telephone call from the chemical pathologist to highlight their patient's risk of FH and suggest specialist referral, whereas with the controls' GPs were not telephoned. Results: After 12 months follow-up, 27 (27%) cases were referred to clinic compared with 4 (4%) controls (p<0.0001). 25 cases were reviewed at clinic, 12 (48%) had definite FH and 18 (72%) had probable or definite FH according to the Dutch Lipid Clinic Network Criteria, 2 cases did not attend their clinic appointments. Genetic testing was performed in 23 individuals: 7 (30%) had pathogenic FH mutations. Genotypic cascade screening of 4 kindreds from the intervention group detected an additional 7 individuals with FH and excluded 5 mutation-negative family members. Conclusions: A telephone call from a chemical pathologist to the requesting GP of patients at high risk of FH was associated with significantly higher rates of FH detection and specialist referral. Over 70% of individuals with an LDL-cholesterol ≥6.5mmol/L were diagnosed with FH. However, further investigation is required to improve the relatively low referral rate. © 2014 Elsevier Ireland Ltd.

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