A study of hospitalized COVID-19 patients with AKI in a setting of multiracial developing country.

BACKGROUND: The commonest indication for hospitalization in COVID-19 patients is hypoxemia or severe respiratory symptoms. However, COVID-19 disease may result in extrapulmonary complications including kidney-related pathology. The reported incidence of renal involvement related to COVID infection varies based on geographical location. OBJECTIVE: This study aimed to assess the incidence rate of AKI in hospitalized COVID-19 patients and identify risk factors and prognostic predictors. METHOD: In this retrospective study, we recruited hospitalized COVID-19 patients from January 2021 until June 2021 at the University Malaya Medical Center. The inclusion criteria were hospitalized for ≥ 48 h with confirmed COVID-19 infection and at least 18 years old. Patient demographic and clinical data were collected from electronic medical records. The staging of AKI was based on criteria as per KDIGO guidelines. RESULTS: One thousand five hundred twenty-nine COVID patients fulfilled the inclusion criteria with a male-to-female ratio of 759 (49.6%) to 770 (50.3%). The median age was 55 (IQR: 36-66). 500 patients (32.7%) had diabetes, 621 (40.6%) had hypertension, and 5.6% (n = 85) had pre-existing chronic kidney disease (CKD). The incidence rate of AKI was 21.1% (n = 323). The percentage of COVID patients in different AKI stages of 1,2 and 3 were 16.3%, 2.1%, and 2.7%, respectively. Fifteen hospitalized patients (0.98%) required renal replacement therapy. 58.8% (n = 190) of AKI group had complete recovery of kidney function. Demographic factors included age (p < 0.001), diabetes (p < 0.001), hypertension (p < 0.012), CKD (p < 0.001), and vaccination status (p = 0.042) were associated with an increased risk of developing AKI. We found that the AKI cohort had statistically significant lower platelet counts and higher ferritin levels than the non-AKI cohort. AKI is a risk predictor of prolonged hospitalization (p < 0.001) and higher mortality rates (P < 0.001). CONCLUSION: AKI is a common clinical complication among hospitalized COVID-19 patients. The etiology of AKI is multifactorial and may have an adverse impact on patient morbidity and mortality.

Calculated parameters for the diagnosis of Wilson disease.

Introduction: The diagnosis of Wilson disease (WD) is plagued by biochemical and clinical uncertainties. Thus, calculated parameters have been proposed. This study aimed to: (a) compare the diagnostic values of non-caeruloplasmin copper (NCC), NCC percentage (NCC%), copper-caeruloplasmin ratio (CCR) and adjusted copper in WD; and (b) derive and evaluate a discriminant function in diagnosing WD. Methods: A total of 213 subjects across all ages who were investigated for WD were recruited. WD was confirmed in 55 patients, and the rest were WD free. Based on serum copper and caeruloplasmin values, NCC, NCC%, CCR and adjusted copper were calculated for each subject. A function was derived using discriminant analysis, and the cut-off value was determined through receiver operating characteristic analysis. Classification accuracy was found by cross-tabulation. Results: Caeruloplasmin, total copper, NCC, NCC%, CCR, adjusted copper and discriminant function were significantly lower in WD compared to non-WD. Discriminant function showed the best diagnostic specificity (99.4%), sensitivity (98.2%) and classification accuracy (99.1%). Caeruloplasmin levels <0.14 g/L showed higher accuracy than the recommended 0.20 g/L cut-off value (97.7% vs. 87.8%). Similarly, molar NCC below the European cut-off of 1.6 umol/L showed higher accuracy than the American cut-off of 3.9 umol/L (80.3% vs. 59.6%) (P < 0.001). NCC%, mass NCC, CCR and adjusted copper showed poorer performances. Conclusion: Discriminant function differentiates WD from non-WD with excellent specificity, sensitivity and accuracy. Performance of serum caeruloplasmin <0.14 g/L was better than that of <0.20 g/L. NCC, NCC%, CCR and adjusted copper are not helpful in diagnosing WD.

Validation of the Hepamet fibrosis score in a multi-ethnic Asian population.

INTRODUCTION AND OBJECTIVES: The Hepamet fibrosis score was introduced for the diagnosis of advanced liver fibrosis in patients with non-alcoholic fatty liver disease (NAFLD). To date, external validation is limited, and its utility in combination with liver stiffness measurement (LSM) has not been explored. MATERIAL AND METHODS: This is a cross-sectional study on NAFLD patients who had a liver biopsy and LSM on the same day. The diagnostic performance of the Hepamet fibrosis score was evaluated using the area under the receiver operating characteristic curve (AUROC). RESULTS: The data for 196 patients were analyzed (mean age 50 ± 11 years old, 50% men, 56.6% Malay, 27.6% Chinese, 15.8% Indian, 67.9% NASH, 15.8% advanced liver fibrosis). The AUROC of Hepamet fibrosis score for the diagnosis of advanced liver fibrosis was 0.85 (95% CI, 0.80 - 0.91). Using the <0.12 and ≥0.47 cut-offs from the original study, the sensitivity, specificity, positive predictive value, negative predictive value, the proportion of indeterminate results and misclassification rate were 81.8%, 91.8%, 47.4%, 98.2%, 32.1% and 6.1%, respectively. Using LSM <10 kPa and ≥15 kPa for the diagnosis of absence and presence of advanced liver fibrosis, respectively, in patients with Hepamet fibrosis score ≥0.47 (i.e., the two-step approach) reduced indeterminate results and misclassification to 16.1% and 3.6%, respectively. CONCLUSIONS: We found the Hepamet fibrosis score to have good diagnostic accuracy in a population that was largely unrepresented in earlier work and demonstrated its utility in a two-step approach with LSM for the diagnosis of advanced liver fibrosis.

Limited applicability of cathepsin D for the diagnosis and monitoring of non-alcoholic steatohepatitis.

BACKGROUND AND AIM: To date, there are limited data on the applicability of cathepsin D for the diagnosis and monitoring of non-alcoholic steatohepatitis (NASH). METHODS: This study included patients with biopsy-proven non-alcoholic fatty liver disease (NAFLD) diagnosed between November 2012 and October 2015. Serum cathepsin D levels were measured using the CatD enzyme-linked immunosorbent assay (USCN Life Science, Wuhan, China) using stored samples collected on the same day of the liver biopsy procedure. The performance of cathepsin D in the diagnosis and monitoring of NASH was evaluated using receiver operating characteristic analysis. RESULTS: Data for 216 liver biopsies and 34 healthy controls were analyzed. The mean cathepsin D level was not significantly different between NAFLD patients and controls; between NASH and non-NASH patients; and across the different steatosis, lobular inflammation, and hepatocyte ballooning grades. The area under receiver operating characteristic curve (AUROC) of cathepsin D for the diagnosis of NAFLD and NASH was 0.62 and 0.52, respectively. The AUROC of cathepsin D for the diagnosis of the different steatosis, lobular inflammation, and hepatocyte ballooning grades ranged from 0.51 to 0.58. Of the 216 liver biopsies, 152 were paired liver biopsies from 76 patients who had a repeat liver biopsy after 48 weeks. There was no significant change in the cathepsin D level at follow-up compared to baseline in patients who had histological improvement or worsening for steatosis, lobular inflammation, and hepatocyte ballooning grades. Cathepsin D was poor for predicting improvement or worsening of steatosis and hepatocyte ballooning, with AUROC ranging from 0.47 to 0.54. It was fair for predicting worsening (AUROC 0.73) but poor for predicting improvement (AUROC 0.54) of lobular inflammation. CONCLUSION: Cathepsin D was a poor biomarker for the diagnosis and monitoring of NASH in our cohort of Asian patients, somewhat inconsistent with previous observations in Caucasian patients. Further studies in different cohorts are needed to verify our observation.

Heavy/light chain assay in the monitoring of multiple myeloma.

Serum protein (SPE) and immunofixation electrophoresis (IFE) have been extensively validated for the routine use of identifying, characterising and quantifying monoclonal proteins. However, accurate quantitation of IgA monoclonal proteins can be difficult when they migrate in to the ß fraction, due to co-migration with transferrin and complement components. The heavy/light chain (HLC) immunoassay is an additional tool for measuring intact immunoglobulin monoclonal proteins. Therefore, we aimed to examine the clinical utility of the HLC assay for the disease monitoring of IgG and IgA multiple myeloma (MM) patients. A total of 177 samples from 30 MM patients (21 IgG and 9 IgA) were analysed retrospectively with median number of six follow up samples per patient (range 3-13). Serum free light chains (sFLC) and HLC were quantified using Freelite and Hevylite immunoassays. Details of M-protein concentration, ß-globulin levels, total immunoglobulin levels and disease treatment response were obtained from the laboratory and patient information system. Passing-Bablok regression analysis was performed to compare (i) M-protein quantification with involved HLC (iHLC) and (ii) total immunoglobulin with summated HLC pairs for each immunoglobulin type (e.g., IgGκ+IgGλ). For 127 IgG MM samples, IgG iHLC levels showed a good correlation with SPE quantification (iHLC y=0.96x+4.9; r=0.917) and summated HLC showed a good correlation with total IgG concentration (summated HLC y=0.94x+5.74; r=0.91). In total, 95/127 (75%) IgG MM follow-up samples had an abnormal HLC ratio and 122/127 (96%) had a positive SPE, probably due to the lower sensitivity of HLC assay in detecting clonality in patients with IgG MM. Consistent with this, one patient assigned a very good partial response by International Myeloma Working Group criteria would be assigned a complete response based on HLC measurements. For 50 IgA MM samples, 42/50 (84%) had an abnormal HLC ratio. Conversely, 50/50 (100%) of M-proteins showed ß fraction migration and were difficult to accurately quantify by SPE. Therefore, M-protein concentration and iHLC did not correlate as well in IgA MM (y=1.9x-8.4; r=0.8) compared to IgG MM. However, there was good correlation between total IgA and summated IgA HLC (IgAκ+IgAλ y=1.35x-0.33; r=0.95). Of the 8/50 (16%) IgA samples with a normal HLC ratio, 6/8 (75%) were consistent with the disease status being in complete remission. Interestingly, in one IgA MM patient, SPE and IFE were negative, but the serum FLC ratio and involved FLC were highly abnormal, consistent with the presence of light chain escape. Our data suggest HLC measurements could add value to the current disease monitoring of MM patients. In IgG MM patients, the M-protein level correlated well with HLC values. The HLC assay complements the serum FLC assay and is especially useful for monitoring of IgA MM patients who display M-proteins migrating in the ß region on SPE.

MACK-3 (combination of hoMa, Ast and CK18): A promising novel biomarker for fibrotic non-alcoholic steatohepatitis.

INTRODUCTION: MACK-3 (combination of hoMa, Ast and CK18) was reported to be a good biomarker for the diagnosis of fibrotic non-alcoholic steatohepatitis (NASH). However, there is no external validation to date. AIM: To evaluate the accuracy of MACK-3 for the diagnosis of fibrotic NASH. METHODOLOGY: Consecutive adult non-alcoholic fatty liver disease (NAFLD) patients who had liver biopsy in a university hospital were included. MACK-3 was calculated using the online calculator using the following variables: fasting glucose, fasting insulin, aspartate aminotransferase (AST) and cytokeratin 18 (CK18). MACK-3 cut-offs ≤0.134 and ≥0.550 were used to predict absence and presence of fibrotic NASH, respectively. Histopathological examination of liver biopsy specimen was reported according to the NASH Clinical Research Network Scoring System. RESULTS: Data for 196 subjects were analysed. MACK-3 was good for diagnosis of fibrotic NASH (area under receiver-operating characteristics curve [AUROC] 0.80), comparable to the Fibrosis-4 index (FIB4) and the NAFLD fibrosis score (NFS) and superior to the BARD score and CK18. MACK-3 was good for diagnosis of active NASH (AUROC 0.81) and was superior to other blood fibrosis tests. The overall accuracy, percentage of subjects in grey zone, sensitivity, specificity, positive predictive value and negative predictive value of MACK-3 for diagnosis of fibrotic NASH was 79.1%, 46.9%, 100%, 43.8%, 43.1% and 100%, respectively, while for diagnosis of active NASH was 90.0%, 39.3%, 84.2%, 81.4%, 88.9% and 74.5%, respectively. CONCLUSION: MACK-3 is promising as a non-invasive test for active NASH and fibrotic NASH and may be useful to identify patients who need more aggressive intervention.

Leptin and soluble leptin receptor in association with gestational diabetes: a prospective case-control study.

PURPOSE: To assess the association of serum leptin and its receptor (SLeptinR) with the risk of gestational diabetes mellitus (GDM) and to evaluate the longitudinal circulation of these peptides in pregnancy. METHODS: This study consisted of 53 subjects diagnosed with GDM and 43 normal glucose tolerance (NGT) pregnant women. Serum leptin and SLeptinR were measured at 24-28 weeks, prior and after delivery, and post-puerperium. RESULTS: Lower levels of leptin and SLeptinR were observed in GDM compared to NGT. Leptin [OR 0.97 (95% CI 0.94-1.0)] and SLeptinR [OR 0.86 (95% CI 0.79-0.93]) were inversely associated with GDM. Participants in the lowest tertile for leptin and SLeptinR had a 2.8-fold (95% CI 1.0-7.6) and a 5.7-fold (95% CI 1.9-17.3) higher risk of developing GDM compared with the highest tertile, respectively. These relationships were attenuated after adjustment for covariates. In both the groups, peak leptin was observed at 24-28 weeks, decreasing continuously during pregnancy (p > 0.05) and after delivery (p < 0.017). SLeptinR level increased (p < 0.001) during pregnancy and decreased (p < 0.005) after delivery in GDM, however, levels remained the same in NGT. In GDM, leptin and SLeptinR was positively and inversely correlated with BMI and HOMA-IR at 24-28 weeks and post-puerperium, respectively. The cord levels of both leptin and SLeptinR were lower than maternal levels. There were no significant differences in serum cord leptin and SLeptinR levels between the groups. CONCLUSION: Leptin and SLeptinR are independently and inversely associated with GDM. Lower levels of these peptides may play an important role in the pathophysiology of GDM and pre-diabetic state in post-puerperium.

Serum Wisteria floribunda agglutinin-positive Mac-2 binding protein in non-alcoholic fatty liver disease.

Wisteria floribunda agglutinin-positive Mac-2 binding protein (WFA+-M2BP) has been suggested to be useful for the assessment of disease severity in non-alcoholic fatty liver disease (NAFLD). Consecutive adult NAFLD patients who had a liver biopsy were included. Serum WFA+-M2BP level was measured using a lectin-antibody sandwich immunoassay using a chemiluminescence enzyme immunoassay machine (HISCL-5000, Sysmex, Kobe, Japan). The measured levels were indexed using the following equation: Cut-off index (COI) = ([WFA+-M2BP]sample-[WFA+-M2BP]NC) / ([WFA+-M2BP]PC-[WFA+-M2BP]NC), where PC = positive control and NC = negative control. Histopathological examination of liver biopsy specimen was reported according to Non-Alcoholic Steatohepatitis (NASH) Clinical Research Network Scoring System. Data for 220 cases were analyzed. The AUROC of the COI for the diagnosis of NASH was 0.65. The AUROC of the COI for the diagnosis of steatosis grade ≥2 and 3 was 0.64 and 0.53, respectively. The AUROC of the COI for the diagnosis of lobular inflammation grade ≥1, ≥2 and 3 was 0.57, 0.68 and 0.59, respectively. The AUROC of the COI for the diagnosis of hepatocyte ballooning grade ≥1 and 2 was 0.64 and 0.65, respectively. The AUROC of the COI for the diagnosis of fibrosis stage ≥1, ≥2, ≥3 and 4 was 0.61, 0.71, 0.74 and 0.84, respectively. Out of the 220 cases, 152 cases were the same 76 patients who had a repeat liver biopsy after 48 weeks of intervention. The AUROC of the change in the COI to detect improvement in steatosis, lobular inflammation, hepatocyte ballooning and fibrosis was 0.57, 0.54, 0.59 and 0.52, respectively. In conclusion, serum WFA+-M2BP was most useful for the diagnosis of significant fibrosis, advanced fibrosis and cirrhosis in NAFLD patients. However, it was less useful for differentiating NASH from non-NASH, and for diagnosis and follow-up of the individual histopathological components of NASH.

N-Carbamylglutamate Is an Effective Treatment for Acute Neonatal Hyperammonaemia in a Patient with Methylmalonic Aciduria.

N-carbamylglutamate (NCG) has been used in combination with ammonia scavengers (sodium benzoate, sodium phenylbutyrate) and dialysis to treat hyperammonaemia in methylmalonic aciduria (MMA). The sole use of NCG for acute neonatal hyperammonaemia secondary to MMA is demonstrated in a neonate presenting at day 9 with encephalopathy, severe metabolic acidosis, hyperammonaemia (1,089 µmol/l), ketonuria and urinary methylmalonic acids. Emergency treatment included discontinuing protein feeds, providing high calories, carnitine and hydroxocobalamin. NCG 200 mg given at 0 and 90 min decreased plasma ammonia dramatically from 1,089 to 567 µmol/l at 90 min and further to 236 µmol/l at 6 h. Normalisation of ammonia was achieved at 12 h with two further doses of NCG 100 mg. This allowed for early re-institution of feeds at 14 h, followed by metabolic stabilization and recovery. Due to the effectiveness of NCG in this case, the use of the more invasive conventional ammonia-lowering therapeutic options could be avoided.

Clinical and autoantibody profile in systemic sclerosis: baseline characteristics from a West Malaysian cohort.

AIM: To evaluate the clinical and antibody profile of systemic sclerosis (SSc) in a Malaysian cohort. METHODS: Consecutive patients with SSc in University Malaya Medical Centre from March to November 2012 were included in this study. In addition to clinical characterization, all subjects underwent autoantibody testing using Euroline immunoblot assay. The association between clinical features and autoantibody profile was evaluated. RESULTS: There were 31, predominantly Chinese (45.2%), subjects. Limited cutaneous disease was the most common subtype (71%). Raynaud's phenomenon was the most commonly observed feature (83.9%). Nine (29%) had esophageal dysmotility symptoms and 23 (74.2%), including all patients with diffuse SSc, had symptoms of gastro-esophageal reflux disease (GERD). Restrictive pattern on pulmonary function test and evidence of lung fibrosis were seen in more than 70% of patients. Echocardiographic evidence of pulmonary arterial hypertension was seen in 58.1%. Telangiectasia, calcinosis, digital ulcers, digital pulp loss or pitting were seen more commonly in the diffuse subtype. The two most prevalent autoantibodies were anti-Scl-70 and anti-Ro-52. The presence of anti-Scl-70 was significantly associated with restrictive lung disease (P = 0.05). Anti-Ro-52 was associated with control subjects with other autoimmune diseases (P = 0.043). The presence of anti-PM-Scl-75 was associated with overlap syndrome (P = 0.032). Patients with anticentromere antibodies were more likely to have vasculitic rash (P = 0.012). CONCLUSION: In Malaysia, SSc most commonly affects the Chinese. Limited cutaneous is more common than diffuse subtype. Features of CREST (calcinosis, Reynaud disease, esophageal dysmotility, sclerodactyly, telangiectasia) are more commonly observed in the diffuse cutaneous subgroup. Anti-Scl-70 and anti-Ro-52 antibodies are promising biomarkers for pulmonary involvement in SSc.

Succinic Semialdehyde Dehydrogenase Deficiency in a Chinese Boy: A Novel ALDH5A1 Mutation With Severe Phenotype.

Succinic semialdehyde dehydrogenase deficiency is a rare autosomal recessive disorder affecting catabolism of the neurotransmitter gamma-aminobutyric acid (GABA), with a wide range of clinical phenotype. We report a Malaysian Chinese boy with a severe early onset phenotype due to a previously unreported mutation. Urine organic acid chromatogram revealed elevated 4-hydroxybutyric acid. Magnetic resonance imaging (MRI) of the brain demonstrated cerebral atrophy with atypical putaminal involvement. Molecular genetic analysis showed a novel homozygous 3-bp deletion at the ALDH5A1 gene c.1501_1503del (p.Glu501del). Both parents were confirmed to be heterozygotes for the p.Glu501del mutation. The clinical course was complicated by the development of subdural hemorrhage probably as a result of rocking the child to sleep for erratic sleep-wake cycles. This case illustrates the need to recognize that trivial or unintentional shaking of such children, especially in the presence of cerebral atrophy, can lead to subdural hemorrhage.

Limited utility of plasma M30 in discriminating non-alcoholic steatohepatitis from steatosis--a comparison with routine biochemical markers.

INTRODUCTION: The utility of Cytokeratin-18 fragment, namely CK18Asp396 (M30), for the diagnosis of non-alcoholic steatohepatitis (NASH) is currently uncertain. We aimed to provide further data in this area among multi-ethnic Asian subjects with NAFLD. MATERIALS AND METHODS: The accuracy of M30 for detecting NASH was compared with serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma glutamyl transpeptidase (GGT) levels in consecutive adult subjects with biopsy-proven non-alcoholic fatty liver disease (NAFLD). RESULTS: Data for 93 NAFLD subjects (mean age 51.0 ± 11.1 years old and 51.6% males) and 20 healthy controls (mean age 50.2 ± 16.4 years old and 33.3% males) were analyzed. There were 39 NASH subjects (41.9%) and 54 non-NASH subjects (58.1%) among the NAFLD subjects. Plasma M30 (349 U/L vs. 162 U/L), and serum ALT (70 IU/L vs. 26 IU/L), AST (41 IU/L vs. 20 IU/L) and GGT (75 IU/L vs. 33 IU/L) were significantly higher in NAFLD subjects than in healthy controls. Serum ALT (86 IU/L vs. 61 IU/L), AST (58 IU/L vs. 34 IU/L) and GGT (97 IU/L vs. 56 IU/L) were significantly higher in NASH subjects compared to non-NASH subjects, but no significant difference was observed with plasma M30 (435 U/L vs. 331 U/L). The accuracy of plasma M30, and serum ALT, AST and GGT was good for predicting NAFLD (AUROC 0.91, 0.95, 0.87 and 0.85, respectively) but less so for NASH (AUROC 0.59, 0.64, 0.75 and 0.68, respectively). Serum ALT and AST, but not plasma M30 showed a significant trend with increasing grades of ballooning and lobular inflammation. CONCLUSION: The utility of M30 in the detection of NASH in clinical practice appears limited, in comparison to routine biochemical markers.

Pattern of tissue expression of CA-125 and HE4 in primary epithelial ovarian tumours and correlation with serum CA-125 levels.

The objective of this study is to assess tissue expression of CA-125 and HE4 protein in primary benign and malignant epithelial tumours of the ovary and correlate with serum CA-125 levels. A total of 100 formalin-fixed, paraffin embedded sections of ovarian tumours which included serous adenoma (11), mucinous adenoma (42), serous carcinoma (20), mucinous carcinoma (12) and endometrioid carcinoma (15), histologically diagnosed between 1st January 2004 to 31st December 2012 at the University Malaya Medical Centre, were stained for HE4 (rabbit polyclonal antibody, Abcam, UK) and CA-125 (mouse monoclonal antibody clone: OC125, Cell Marque Corporation, Rocklin, California, USA). Pre-operative serum CA-125 levels were obtained from the laboratory information system. Immunoscore (I score) for HE4 and CA-125 was given based on the intensity of staining and percentage of positive tumour cells and considered significant when it was >50 (intensity of staining multiplied by percentage of positive tumour cells). Serum CA-125 levels were compared with the I score of HE4 and CA-125 in tissues. We noted that the CA-125 levels in serum and tissues were significantly raised in malignant compared to benign ovarian tumours (p value<0.05). Tissue expression of HE4 protein was also significantly raised in malignant tumours compared to benign tumours (p value<0.05). We conclude that HE4 can be a useful tissue immunomarker in addition to CA-125.

Effect of HbE heterozygosity on the measurement of HbA1c.

AIM: Measurement of HbA1c provides an excellent measure of glycaemic control for diabetic patients. However, haemoglobin (Hb) variants are known to interfere with HbA1c analysis. In our laboratory HbA1c measurement is performed by Variant II turbo 2.0. The aim of this study is to investigate the influence of HbE trait on HbA1c analysis. METHODS: Haemoglobin variants were identified by HbA1c analysis in 93 of 3522 samples sent to our laboratory in a period of 1 month. Haemoglobin analysis identified HbE trait in 81 of 93 samples. To determine the influence of HbE trait on HbA1c analysis by Variant II Tubo 2.0, boronate affinity high performance liquid chromatography (HPLC) method (Primus PDQ) was used as the comparison method. Two stage linear regression analysis, Bland Altman plot and Deming regression analysis were performed to analyse whether the presence of HbE trait produced a statistically significant difference in the results. The total allowable error for HbA1c by the Royal Australasian College of Pathologists (RCPA) external quality assurance is 5%. Hence clinically significant difference is more than 5% at the medical decision level of 6% and 9%. RESULTS: Statistically and clinically significant higher results were observed in Variant II Turbo 2.0 due to the presence of HbE trait. A positive bias of ∼10% was observed at the medical decision levels. CONCLUSION: Laboratories should be cautious when evaluating HbA1c results in the presence of haemoglobin variants.

Plasma, aqueous and vitreous homocysteine levels in proliferative diabetic retinopathy.

BACKGROUND/AIMS: To compare homocysteine (Hcy) concentration in the blood plasma, vitreous and aqueous of eyes with proliferative diabetic retinopathy (PDR) against control, and to investigate associations between Hcy concentration in blood plasma with that of aqueous and vitreous in these two groups. METHODS: Blood plasma, aqueous and vitreous samples were collected during combined cataract and pars plana vitrectomy from 20 eyes with PDR and 21 eyes of patients without diabetes mellitus. Hcy concentration in the samples was determined by chemiluminescent microparticle immunoassay. RESULTS: The mean Hcy concentration (± standard deviation) of blood plasma, vitreous and aqueous were 13.7± 2.2 µmol/l, 3.4±0.7 µmol/l and 1.6±0.3 µmol/l respectively in the PDR group; in the control group, they were 10.4±1.1 µmol/l, 2.6±0.9 µmol/l and 1.2±0.2 µmol/l, respectively. The estimated geometric mean of Hcy concentration of all three variables in the PDR group was about 30% higher than control. In the PDR group, Hcy concentration between the blood plasma and vitreous was significantly associated (ρ=0.71; p-value < 0.001), as was that between the blood plasma and aqueous (ρ=0.68; p-value < 0.001). In the control group, only Hcy concentration in the blood plasma and vitreous was significantly associated (ρ=0.66; p-value = 0.001). CONCLUSION: The geometric mean of Hcy concentration in the blood plasma, vitreous and aqueous of the PDR group was significantly higher than control. The Hcy levels in the blood plasma and vitreous were also significantly associated in both groups. However, the blood plasma and aqueous were significantly associated only in the PDR group.

Reference value for cardiac troponin I in a multi-ethnic group.

AIM: The aim of this study was to evaluate the distribution of cardiac troponin I (cTnI) values, measured by the ADVIA TnI-Ultra method in a multi-ethnic group and to determine the imprecision of the assay. METHOD: The study population comprised 234 men and 208 women and the age range was 18-73 years. Recruitment was aimed at enrolling different races and comprised 186 Malays, 136 Chinese and 120 Indians. We evaluated the analytical performance the ultra sensitive cardiac troponin I (cTnI) assay. RESULTS: The mean values for cTnI for male and female were 0.011 microg/L and 0.010 microg/L respectively. No significant difference was noted between male and female populations (p > 0.05). The 99th percentile for ADVIA TnI-Ultra was 0.061 microg/L. The mean values of cTn in Malay, Chinese and Indian groups were 0.011, 0.011 and 0.011 microg/L, respectively. There was no significant difference between the different ethnic populations (p > 0.05). The assay imprecision was less than 10% at concentrations higher than 0.036 microg/L. CONCLUSION: ADVIA TnI-Ultra assay showed no difference in the troponin values among different ethnic groups and between males and females. Hence a single cut-off value based on the 99th percentile can be used.

Comparing measured total carbon dioxide and calculated bicarbonate.

INTRODUCTION: The objective of the study is to determine the level of agreement between measured total carbon dioxide (TCO2) and calculated bicarbonate (HCO3-) in our laboratory. MATERIALS AND METHODS: TCO2 and HCO3- values of 1820 samples drawn at the same time from the patient were compared. TCO2 from venous samples was measured on Dimension RxL while HCO3- was obtained from arterial blood gas samples analyzed on Radiometer ABL 700. RESULTS: The TCO2 and HCO3- values correlated well (r = 0.977, p < 0.001), with the correlation given by the equation, y = 0.986x - 0.5335. Using Bland-Altman analysis, the bias was 0.87 mmol/L (SD 1.42 mmol/L), and the limits of agreement (LOA) were -1.92 to 3.67 mmol/L. Story and Poustie's criteria were applied to study the agreement between these two methods. Based on the first criterion that the bias between TCO2 and HCO3- should be less than +/- 1 mmol/L, the results for the two methods appear to be in good agreement. The second criterion requires that the LOA between the two methods should range between a bias of +/- 2 mmol/L or a total span of 4 mmol/L; the LOA was exceeded in our study. Using the total allowable error in the Bland Altman plot also showed that the two values cannot be used interchangeably especially at the lower values. CONCLUSIONS: TCO2 did not show good agreement with HCO3-. Clinicians should be aware of this discrepancy and hence should be cautious when using HCO3- for management of acid-base disorders.