Water Conservation Overrides Osmotic Diuresis During SGLT2 Inhibition in Patients With Heart Failure

BACKGROUND

Sodium-glucose cotransporter 2 inhibitors are believed to improve cardiac outcomes due to their osmotic diuretic potential.

OBJECTIVES

The goal of this study was to test the hypothesis that vasopressin-driven urine concentration overrides the osmotic diuretic effect of glucosuria induced by dapagliflozin treatment.

METHODS

DAPA-Shuttle1 (Hepato-renal Regulation of Water Conservation in Heart Failure Patients With SGLT-2 Inhibitor Treatment) was a single-center, double-blind, randomized, placebo-controlled trial, in which patients with chronic heart failure NYHA functional classes I/II and reduced ejection fraction were randomly assigned to receive dapagliflozin 10 mg daily or placebo (1:1) for 4 weeks. The primary endpoint was change from baseline in urine osmolyte concentration. Secondary endpoints included changes in copeptin levels and solute free water clearance.

RESULTS

Thirty-three randomized, sodium-glucose cotransporter 2 inhibitor-naïve participants completed the study, 29 of whom (placebo: n = 14; dapagliflozin: n = 15) provided accurate 24-hour urine collections (mean age 59 ± 14 years; left ventricular ejection fraction 31% ± 9%). Dapagliflozin treatment led to an isolated increase in urine glucose excretion by 3.3 mmol/kg/d (95% CI: 2.51-4.04; P < 0.0001) within 48 hours (early) which persisted after 4 weeks (late; 2.7 mmol/kg/d [95% CI: 1.98-3.51]; P < 0.0001). Dapagliflozin treatment increased serum copeptin early (5.5 pmol/L [95% CI: 0.45-10.5]; P < 0.05) and late (7.8 pmol/L [95% CI: 2.77-12.81]; P < 0.01), leading to proportional reductions in free water clearance (early: -9.1 mL/kg/d [95% CI: -14 to -4.12; P < 0.001]; late: -11.0 mL/kg/d [95% CI: -15.94 to -6.07; P < 0.0001]) and elevated urine concentrations (late: 134 mmol/L [95% CI: 39.28-229.12]; P < 0.01). Therefore, urine volume did not significantly increase with dapagliflozin (mean difference early: 2.8 mL/kg/d [95% CI: -1.97 to 7.48; P = 0.25]; mean difference late: 0.9 mL/kg/d [95% CI: -3.83 to 5.62]; P = 0.70).

CONCLUSIONS

Physiological-adaptive water conservation eliminated the expected osmotic diuretic potential of dapagliflozin and thereby prevented a glucose-driven increase in urine volume of approximately 10 mL/kg/d · 75 kg = 750 mL/kg/d. (Hepato-renal Regulation of Water Conservation in Heart Failure Patients With SGLT-2 Inhibitor Treatment [DAPA-Shuttle1]; NCT04080518).

Commutability assessment of human urine certified reference materials for albumin and creatinine on multiple clinical analyzers using different statistical models

Urine albumin concentration and albumin-creatinine ratio are important for the screening of early-stage kidney damage. Commutable urine certified reference materials (CRMs) for albumin and creatinine are necessary for standardization of urine albumin and accurate measurement of albumin-urine ratio. Two urine CRMs for albumin and creatinine with certified values determined using higher-order reference measurement procedures were evaluated for their commutability on five brands/models of clinical analyzers where different reagent kits were used, including Roche Cobas c702, Roche Cobas c311, Siemens Atellica CH, Beckman Coulter AU5800, and Abbott Architect c16000. The commutability study was conducted by measuring at least 26 authentic patient urine samples and the human urine CRMs using both reference measurement procedures and the routine methods. Both the linear regression model suggested by the Clinical and Laboratory Standard Institute (CLSI) guidelines and log-transformed model recommended by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Commutability Working Group were used to evaluate the commutability of the human urine CRMs. The commutability of the human urine CRMs was found to be generally satisfactory on all five clinical analyzers for both albumin and creatinine, suggesting that they are suitable to be used routinely by clinical laboratories as quality control or for method validation of urine albumin and creatinine measurements.

Comparative Clinical Evaluation of the Roche Elecsys and Abbott Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Serology Assays for Coronavirus Disease 2019 (COVID-19)

CONTEXT.—

The use of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serologic tests detects antibodies in the host, contributing to the identification of individuals who have been exposed to coronavirus disease 2019 (COVID-19).

OBJECTIVE.—

To critically evaluate 2 commercially available SARS-CoV-2 serology tests.

DESIGN.—

A total of 333 unique, nonduplicated serum samples obtained from COVID-19 patients (n = 170) and negative controls (n = 163) obtained before December 2019 were used in the study. Samples were tested on the Roche E411 and Abbott Architect i4000SR platforms, and results were correlated to reverse transcription polymerase chain reaction (PCR) results and clinical symptoms.

RESULTS.—

There was a strong level of agreement in the qualitative results between both assays, with a Cohen κ value of .840, P < .001. The specificity for both Roche and Abbott were excellent at 100%. Roche exhibited marginally better performance in the 21 days or more group with a sensitivity of 90.6% (95% CI, 75.8%-96.8%) versus an Abbott sensitivity of 84.4% (95% CI, 68.3%-93.1%), as well as in the 14- to 20-day group with a sensitivity of 85.7% (95% CI, 65.4%-95.0%) versus an Abbott sensitivity of 81.0% (95% CI, 60.0%-92.3%). Less than 14 days of symptoms groups exhibited poor sensitivity at less than 50% for both assays. The areas under curve (± standard error) for Roche (0.894 ± 0.025, P < .001) and Abbott (0.884 ± 0.026, P < .001) were very similar. Potential confounders for negative serologic results include antiretroviral medication use and pauci-symptomatic patients.

CONCLUSIONS.—

Specificities for high-throughput Roche and Abbott immunoassays are excellent, but users need to be cautious to interpret serologic test results after 14 days of symptoms to avoid false negatives.

Clinical evaluation of serological IgG antibody response on the Abbott Architect for established SARS-CoV-2 infection

OBJECTIVE

This study aimed to evaluate the diagnostic performance of the Abbott Architect SARS-CoV-2 IgG assay in COVID-19 patients.

METHODS

Residual sera from 177 symptomatic SARS-CoV-2-positive patients and 163 non-COVID-19 patients were tested for antibody with the Abbott SARS-CoV-2 IgG assay (Abbott Diagnostics, Chicago, USA). Clinical records for COVID-19 patients were reviewed to determine the time from onset of clinical illness to testing.

RESULTS

Specificity of the assay was 100.0% (95%CI: 97.1-100.0%). The clinical sensitivity of the assay varied depending on time from onset of symptoms, increasing with longer periods from the onset of clinical illness. The clinical sensitivity at ≤6 days was 8.6% (7/81; 95%CI: 3.8-17.5%), at 7-13 days 43.6% (17/39; 95%CI: 28.2-60.2%), at 14-20 days 84.0% (21/25; 95%CI: 63.1-94.7%), and at ≥21 days 84.4% (27/32; 95%CI: 66.5-94.1%). Clinical sensitivity was higher in the ≥14-day group compared to <14 days. There were no differences between the 14-20-day and ≥21-days groups; the combined clinical sensitivity for these groups (≥14 days) was 84.2% (49/57; 71.6-92.1%).

CONCLUSION

The Abbott SARS-CoV-2 IgG test has high specificity. Clinical sensitivity was limited in the early stages of disease but improved from 14 days after the onset of clinical symptoms.

Practical laboratory considerations amidst the COVID-19 outbreak: early experience from Singapore

The coronavirus disease 2019 (COVID-19) is a zoonotic viral infection originating from Wuhan, China in December 2019. The World Health Organization has classified this pandemic as a global health emergency due to its virulent nature of transmission, which may lead to acute respiratory distress syndrome. Singapore's health ministry has responded with enhanced surveillance of COVID-19 for all suspected pneumonia cases, further increasing the volume of testing via real-time reverse transcription PCR, as well as samples necessitating stringent infectious control. Collectively, this has implications on the total testing process, laboratory operations and its personnel due to biosafety concerns. Turnaround time for routine testing may also be affected. The aim of this article is to present our tertiary institution's early experience with managing this emerging crisis and offer practical considerations for the preanalytical, analytical and postanalytical phases of laboratory testing in this cohort of patients.

High prevalence and incidence of tuberculosis in people living with the HIV in Mandalay, Myanmar, 2011-2017

SETTING

Two human immunodeficiency virus (HIV) clinics providing antiretroviral therapy (ART), Mandalay, Myanmar.

OBJECTIVE

To assess prevalent TB at enrolment, incident TB during follow-up and associated risk factors in adult people living with HIV (PLHIV) between 2011 and 2017.

DESIGN

Cohort study using secondary data.

RESULTS

Of 11 777 PLHIV, 2911 (25%) had prevalent TB at or within 6 weeks of enrolment. Independent risk factors for prevalent TB were being male or single/widowed, daily alcohol consumption, CD4 count 200 cells/μl and anaemia. During 6 years follow-up in 8866 PLHIV with no prevalent TB, the rate of new TB was 2.9 per 100 person-years (95%CI 2.6-3.1). Cumulative TB incidence was 9.6%, with 370 (72%) of 517 new TB cases occurring in the first year. Independent risk factors for incident TB were being male and anaemia. Incident TB was highest in the first year of ART, in PLHIV with CD4 counts 200 cells/μl and those not receiving isoniazid preventive therapy (IPT). Incident TB declined with time on ART and rising CD4 counts.

CONCLUSION

Prevalent and incident TB were high in PLHIV in the Mandalay clinics. Consideration should be given to earlier TB diagnosis using more sensitive diagnostic tools, effective ART and scaling up IPT.

Childhood TB in Myanmar: trends in notification, profile and treatment outcomes in the private sector

SETTING

Myanmar National Tuberculosis (TB) programme (NTP).

OBJECTIVE

To describe 1) the trends in childhood TB (aged ⩾ 14 years) notification from 2014 to 2017 and quantify the private sector contribution to this notification; and 2) the profile and treatment outcomes of childhood TB managed in the private sector in 2016.

STUDY DESIGN

This was an observational study involving the review of routine records and reports of the NTP public-private mix (PPM) projects managed by the Myanmar Medical Association and Population Service International.

RESULTS

The total number of childhood TB notified has declined from 36 314 in 2014 to 28 723 in 2017 (average annual decline = 2607 cases per year). The private sector contribution to the notification remained between 17% and 19%. Of the 5616 childhood TB cases diagnosed and treated under the two PPM projects in 2016, 99% were clinically diagnosed and 5459 (97.7%) had successful treatment outcomes. Children aged ⩾10 years, males, those with bacteriologically confirmed TB, those treated in the regions or states of Mandalay, Chin and Shan had a higher risk of an unfavourable outcome (lost to follow-up, death, move to second-line treatment and not evaluated).

CONCLUSION

Childhood TB notification is showing a declining trend. One of five notified childhood TB cases was diagnosed and treated in the private sector, where the successful treatment rate was high.

Maternal HBeAg positivity and viremia associated with umbilical cord blood hepatitis B viremia

BACKGROUND

Hepatitis B (HBV) transmission may result from in utero transmission. We aimed to determine the correlation between maternal serum and umbilical cord blood HBV DNA levels in infants delivered by chronic HBV-infected mothers and to describe the effect of cord blood viremia on vertical transmission.

METHODS

A prospective cohort of 92 chronic HBV-infected mother-and-child pairs recruited over three years was analyzed. Maternal and cord blood were tested for HBV DNA by real-time PCR. Standard immunoprophylaxis with both active and passive immunization was administered to all infants. Serological testing was performed on all infants at 9 months of age.

RESULTS

Moderate positive correlation of the maternal HBV DNA with cord blood HBV DNA was demonstrated (r² = 0.521, p = <0.001). HBeAg +ve mothers were younger with higher HBV and cord viremia. At 9 months of age, one infant was infected. Infants delivered by HBeAg positive mothers and mothers with high HBV DNA of more than 6 LOG IU/mL (1 x 10⁶ IU/mL) have increased relative risk of cord blood viremia.

CONCLUSIONS

Maternal HBV DNA and presence of HBeAg were positively correlated to cord blood HBV DNA in infants delivered by chronic HBV-infected mothers. Our data suggest that reducing maternal viremia during the antenatal period may help to reduce cord blood viremia.

Rifampicin-resistant tuberculosis patients in Myanmar in 2016: how many are lost on the path to treatment?

SETTING

Regional tuberculosis (TB) centres of the Yangon and Mandalay Regions of Myanmar, which account for 65% of all notified rifampicin-resistant tuberculosis (RR-TB) cases countrywide.

OBJECTIVE

To determine 1) initial loss to follow-up (LTFU), 2) treatment delay, and 3) factors associated with initial LTFU and treatment delay among RR-TB patients residing in the Yangon and Mandalay regions diagnosed using Xpert® during January-August 2016.

DESIGN

This was a retrospective cohort study. Each diagnosed patient was tracked in the drug-resistant TB treatment registers of the Yangon and Mandalay regional treatment centres for January-December 2016 using patient name, age, sex, township and date of diagnosis. If the diagnosed patient was not found in the treatment register by 31 December 2016, he/she was considered 'initial LTFU'.

RESULTS

Of the 1037 RR-TB patients diagnosed, 310 (30%) experienced initial LTFU, which was significantly higher among patients aged 55 years and among those diagnosed in the Mandalay Region. A treatment delay of >1 month was observed in 440 (70%) patients (median delay 41 days). Delay was uniformly high across patient subgroups, and was not associated with any factor.

CONCLUSION

Initial LTFU and treatment delays among RR-TB patients were high. Future studies using qualitative research methods are needed to ascertain the reasons for this observation.

Comparing monovalent and combination hepatitis B vaccine outcomes in children delivered by mothers with chronic hepatitis B

AIM

We compared the vaccine effectiveness of monovalent and combination hepatitis B vaccine regimens in infants born to chronic hepatitis B carrier mothers.

METHODS

An observational cohort of neonates was recruited over 78 months from two public hospital maternity units in Singapore. We enrolled term infants, born to chronic hepatitis B surface antigen-positive mothers regardless of their hepatitis Be antigen status, who completed the hepatitis B virus (HBV) vaccination programme in Singapore. Infants born to mothers on antiviral therapy, or with concurrent hepatitis C or human immunodeficiency virus infection were excluded. All infants received hepatitis B immunoglobulin at birth. One group received three doses of monovalent hepatitis B vaccine (0, 1, 6 months) (regimen A). The other group received two doses of monovalent vaccine, followed by one dose combination vaccine DTaP-IPV-Hib-HBV (0, 1, 6 months) (regimen B). Vaccine effectiveness was determined by immunoprophylaxis failure leading to HBV vertical transmission. Immunogenicity was assessed by hepatitis B surface antibody (anti-HBs) levels at 9 months of age.

RESULTS

Total of 177 term neonates received regimen A and 115 received regimen B. Immunoprophylaxis failure rate was low, 2.3 and 2.6% (P = 1.00) in regimen A and B, respectively. Mean anti-HBs titres were similar at 643 ± 374 and 561 ± 396 IU/L (P = 0.08) for regimen A and B, respectively.

CONCLUSION

Hepatitis B vaccine regimens using monovalent or combination vaccine for the third dose showed similarly high vaccine effectiveness and low immunoprophylaxis failure rate in term infants born to chronic hepatitis B carrier mothers.

How many sputum samples should be examined during follow-up of tuberculosis patients in Myanmar: two or one?

Setting: Ten selected microscopy centres in Sagaing Region, Myanmar, functioning under an external quality assurance system with no reported major errors. Objective: To assess the pattern of serial sputum results (NN, both smear-negative; NP, first smear-negative and second smear-positive; PN, first smear-positive and second smear-negative; and PP, both smear-positive) among follow-up sputum microscopy examinations of tuberculosis (TB) patients (end of intensive phase, mid-continuation phase and end of treatment) conducted from 1 November 2017 to 15 April 2018. Design: Cross-sectional study using secondary data (laboratory registers). Results: Of 2001 examinations, 94 (4.7%) were smear-positive: 66 PP (3.3%), 12 PN (0.6%) and 16 NP (0.8%); 75% of NP results were scanty. The proportion of NP results was 0.8% (95%CI 0.5-1.3), i.e., 125 smears (95%CI 77-200) were required to detect one additional smear-positive result in the second sample. Of the 16 NP results (15 patients), 14 were tested using Xpert^® MTB/RIF and none had rifampicin resistance. During the continuation phase of treatment, 13 became smear-negative, one remained smear-positive and one had unknown follow-up smear status. Conclusion: The benefit of the second sputum sample for monitoring anti-tuberculosis treatment was negligible. Given the favourable resource implications (reduced laboratory workload and costs), we recommend changing the policy from two sputum smears to one during follow-up sputum examinations of TB patients.

Serologic Responses After Hepatitis B Vaccination in Preterm Infants Born to Hepatitis B Surface Antigen-Positive Mothers: Singapore Experience

BACKGROUND

The Advisory Committee on Immunization Practices (ACIP) recommends a 4-dose vaccination schedule for preterm low birth weight infants (<2 kg) and a 3-dose vaccination schedule for preterm infants (≥2 kg) born to hepatitis B surface antigen (HBsAg)-positive mothers. However, data remain limited for these high-risk infants, and the optimal dosing schedule in Asia is not well established.

AIM

The aim of this study was to evaluate the serologic vaccine responses in preterm infants born to HBsAg-positive mothers using current vaccination guidelines.

METHODS

Preterm babies of gestation less than 37 completed weeks born to HBsAg-positive mothers were prospectively recruited during 6 years (June 2009 to December 2015) and retrospectively recruited via convenience sampling in 2 years (June 2013 to April 2015) in 2 tertiary pediatric centers. The preterm infants were given 4 or 3 vaccine doses as per ACIP 2005 guidelines. Vaccine response was defined as achieving hepatitis B surface antibody values of >10 IU/L [Abbott Architect (Abbott Laboratories, Chicago, IL)] at 9 months of chronologic age.

RESULTS

A total of 24 preterm infants were recruited. Four had a birth weight <2 kg. Of 23 surviving infants, all were negative for HBsAg. One baby (4.5%) did not achieve adequate vaccine response. All 4 infants with birth weight <2 kg achieved seroprotective values.

CONCLUSION

The current ACIP-recommended vaccination schedule results in adequate antibody responses in preterm infants of HBsAg-positive mothers.

Evaluation of the automated ADVIA centaur® XP syphilis assay for serological testing

We evaluated the performance of the ADVIA Centaur XP Syphilis assay (Siemens Healthcare Diagnostics, Tarrytown, NY, USA) using samples previously tested on the ARCHITECT i4000SR system (Abbott Diagnostics, Lake Forest, IL, USA) and confirmed by the Treponema pallidum particle agglutination assay (TPPA) (SERODIA-TPPA, Fujirebio Diagnostics Inc., Malvern, PA, USA). Clinical patient information was included to aid resolution of discordant samples where available. Precision, interference, and cross-reactivity were also assessed. Relative to patient clinical status, the sensitivity of both the ADVIA Centaur XP and the ARCHITECT assays was 100% (95% CI, 93.9-100), and the specificity of the ADVIA Centaur XP assay was 95.5% (95% CI, 90.4-98.3), which was slightly higher than that of the ARCHITECT assay at 93.9% (95% CI, 88.4-97.3). Overall agreement relative to patient clinical status was 96.9% (95% CI, 93.3-98.8) for the ADVIA Centaur XP assay and 95.8% (95% CI, 91.9-98.2) for the ARCHITECT assay. Overall agreement between the two automated assays was 96.9% (95% CI, 93.3-98.8). ADVIA Centaur XP assay precision was <5% at all index values tested. No significant interference was observed for lipemia or hemolysis; a small effect was seen with some samples for bilirubin. The assay exhibited no significant cross-reactivity with a number of potential interfering factors. The ADVIA Centaur XP Syphilis assay can be considered a sensitive and accurate assay for identification of treponemal antibodies in screening populations as well as patients presenting with suspicion of syphilitic infection.

Limited benefit of hepatitis B immunoglobulin prophylaxis in children of hepatitis B e antigen-negative mothers

INTRODUCTION

In 2006, Singapore adopted the universal hepatitis B immunoglobulin (HBIg) policy. Since then, all infants of hepatitis B surface antigen (HBsAg)-positive mothers receive HBIg, irrespective of maternal hepatitis B e antigen (HBeAg) status. However, the benefits of HBIg for infants of HBeAg-negative mothers are unclear. We compared the vertical transmission rates among children of HBeAg-negative mothers who were given HBIg versus a retrospective cohort who were not given HBIg, to determine its protective effect.

METHODS

This observational study involved pregnant HBsAg-positive women seen at National University Hospital, Singapore, between June 2009 and December 2013. If the infants of these mothers completed the recommended vaccination schedule, they were recruited into the study, along with their older siblings. Serological testing for the children was performed three months after completion of the last dose of vaccine, and hepatitis B virus (HBV) surface gene sequencing was carried out if HBV DNA was detected.

RESULTS

A total of 111 infants and 47 siblings were recruited. 2 (1.5%) children were found to have vertical transmission despite receiving HBIg, while no incidences of vertical transmission were found among the historical controls who did not receive HBIg (p = 1.00).

CONCLUSION

The overall effectiveness of the hepatitis B vaccination programme for children of HBsAg-positive mothers was high, regardless of HBIg administration. The addition of HBIg did not appear to confer additional benefits, in terms of vertical transmission rate, among infants born to HBeAg-negative mothers.

Varicella seroprevalence in healthcare workers in a tertiary hospital: an audit of cross-sectional data

Background

The seroprevalence of varicella in Southeast Asia is not well described especially in healthcare workers (HCW) in the region. We report the varicella seroprevalence among healthcare workers from a diverse range of countries working in a tertiary care hospital in Singapore.

Methods

We audited the results of annual HCW health screening, which included a varicella assay, from the years 2009 to 2014. During this period, there was a change in hospital policy mandating varicella immunity for all newly employed healthcare workers. The serological data were reviewed with employment records on occupation and nationality. Seroprevalence rates were determined by standard commercial enzyme linked immunosorbent assays for each year of testing. Odds of being immune in 2014 were compared by means of multiple logistic regression.

Results

A total of 10,585 samples were obtained from 6668 unique individuals over four separate cross-sections of the hospital workforce. A peak seroprevalence of 92.8 % (95 % CI 92.0–93.5) was recorded in 2014. Younger employees had a lower seroprevalence than their older colleagues. In a consolidated sample of 4875 members of the active workforce in October 2014, we identified that Indian nationals were less likely to be immune than their Singaporean national colleagues, odds ratio (OR) 0.26 (95 % CI 0.17–0.43, p < 0.001), while Chinese nationals were more likely to be immune, OR 4.34 (95 % CI 1.61–12.2, p = 0.004), after controlling for year of screening, gender, age-group and vocation. In 2014, being employed as administrative staff, OR 0.43 (95 % CI 0.29–0.64, p < 0.001) or contract service provider, OR 0.30 (95 % CI 0.19–0.47, p < 0.001), was also associated with a lower odds of being immune than being employed as a nurse.

Conclusions

There remain a small number of healthcare workers who are non-immune to varicella in our tertiary hospital. A new pre-employment policy of mandatory screening and vaccination may have increased rates of immunity but more needs to be done to ensure that all of our employees are immune to varicella to protect our vulnerable patients.

Spot urine estimations are equivalent to 24-hour urine assessments of urine protein excretion for predicting clinical outcomes

Background. The use of spot urine protein to creatinine ratios in estimating 24 hr urine protein excretion rates for diagnosing and managing chronic kidney disease (CKD) predated the standardization of creatinine assays. The comparative predictive performance of spot urine ratios and 24 hr urine collections (of albumin or protein) for the clinical outcomes of CKD progression, end-stage renal disease (ESRD), and mortality in Asians is unclear. We compared 4 methods of assessing urine protein excretion in a multiethnic population of CKD patients. Methods. Patients with CKD (n = 232) provided 24 hr urine collections followed by spot urine samples the next morning. We created multiple linear regression models to assess the factors associated with GFR decline (median follow-up: 37 months, IQR 26-41) and constructed Cox proportional-hazards models for predicting the combined outcome of ESRD and death. Results. The linear regression models showed that 24 hr urine protein excretion was most predictive of GFR decline but all other methods were similar. For the combined outcomes of ESRD and death, the proportional hazards models had similar predictive performance. Conclusions. We showed that all methods of assessments were comparable for clinical end-points, and any method can be used in clinical practice or research.

Psychosis prevalence and physical, metabolic and cognitive co-morbidity: data from the second Australian national survey of psychosis

BACKGROUND

There are insufficient data from nationwide surveys on the prevalence of specific psychotic disorders and associated co-morbidities.

METHOD

The 2010 Australian national psychosis survey used a two-phase design to draw a representative sample of adults aged 18-64 years with psychotic disorders in contact with public treatment services from an estimated resident population of 1 464 923 adults. This paper is based on data from 1642 participants with an International Classification of Diseases (ICD)-10 psychotic disorder. Its aim is to present estimates of treated prevalence and lifetime morbid risk of psychosis, and to describe the cognitive, physical health and substance use profiles of participants.

RESULTS

The 1-month treated prevalence of psychotic disorders was 3.10 cases per 1000 population aged 18-64 years, not accounting for people solely accessing primary care services; lifetime morbid risk was 3.45 per 1000. Mean premorbid intelligence quotient was approximately 0.5 s.d.s below the population mean; current cognitive ability (measured with a digit symbol coding task) was 1.6 s.d.s below the population mean. For both cognitive tests, higher scores were significantly associated with better independent functioning. The prevalence of the metabolic syndrome was high, affecting 60.8% of participants, and pervasive across diagnostic groups. Of the participants, two-thirds (65.9%) were current smokers, 47.4% were obese and 32.4% were sedentary. Of the participants, half (49.8%) had a lifetime history of alcohol abuse/dependence and 50.8% lifetime cannabis abuse/dependence.

CONCLUSIONS

Our findings highlight the need for comprehensive, integrative models of recovery to maximize the potential for good health and quality of life for people with psychotic illness.

Vitamin D and its relationship with markers of bone metabolism in healthy Asian women

BACKGROUND

In this study, we aimed to determine the normal ranges of 25-hydroxy-vitamin D(3) (25-OHD(3)), parathyroid hormone (PTH), and the markers of bone turnover, procollagen type 1 N propeptide (P1NP) and C-terminal cross-linked telopeptide of type 1 collagen (CTX), in normal healthy women in Singapore, and to explore the relationship between vitamin D, PTH, and these markers of bone turnover in the women.

METHODS

One hundred and ninety-seven healthy women, aged 25 to 60, were selected from a hospital staff health screening program; 68% were Chinese, 18% Malay, and 14% Indian. P1NP, CTX, and 25-OHD(3) were measured using the Roche Cobas® electrochemiluminescence immunoassay. Serum PTH was measured using the Siemens ADVIA Centaur® immunoassay.

RESULTS

Sixty-five percent had 25-OHD(3) concentrations <50 nmol/l. Vitamin D insufficiency (25-OHD(3) < 50 nmol/l) was more prevalent in Malays (89%) and Indians (82%) compared to Chinese (56%). There was no correlation between vitamin D and age. PTH positively correlated with age, and Malays and Indians had higher PTH concentrations than Chinese. There was an inverse correlation between PTH and 25-OHD(3), but no threshold of 25-OHD(3) concentrations at which PTH plateaued. The bone turnover markers P1NP and CTX inversely correlated with age but were not different between ethnic groups. CTX and P1NP exhibited good correlation, however, there was no significant correlation between 25-OHD(3) or PTH concentrations and the bone turnover markers P1NP and CTX.

CONCLUSIONS

Healthy women in Singapore have a high prevalence of vitamin D insufficiency. Vitamin D insufficiency was more prevalent in Malays and Indians compared to Chinese.

Comparison of the Elecsys PTH(1-84) assay with four contemporary second generation intact PTH assays and association with other biomarkers in chronic kidney disease patients

OBJECTIVES

The COBAS Elecsys PTH(1-84) assay is a novel, electro-chemiluminescence immunoassay that exclusively measures full-length parathyroid hormone (PTH). The aim of this study is to compare the automated biointact Elecsys PTH(1-84) assay with four contemporary, iPTH assays in chronic kidney disease (CKD) patients.

DESIGN AND METHODS

We compared the Elecsys PTH(1-84) assay with four iPTH assays (Siemens ADVIA Centaur, Ortho Clinical Diagnostics (OCD) VITROS, Beckman Access2, Abbott ARCHITECT) in the measurement of PTH in 83 local CKD patients. Majority of the patients (44) had CKD but were not on dialysis, 15 were on hemodialysis, 15 were on peritoneal dialysis, and 9 were post-renal transplant. The precision performance and correlation of the assays were determined. PTH(1-84) concentrations were correlated with calcium, phosphate, alkaline phosphatase, hemoglobin, HbA1c and lipid concentrations.

RESULTS

The Elecsys PTH(1-84) assay showed comparable precision and good correlation with the iPTH assays. Although the four different iPTH assays correlated well with each other, there was significant discrepancy among assays. The discrepancy among assays increased with increasing PTH concentrations. The ADVIA Centaur and ARCHITECT assays measured significantly higher PTH concentrations than the VITROS and Access2 assays. PTH(1-84) showed a positive association with phosphate and alkaline phosphatase and an inverse association with HbA1c. There was no significant association with lipid concentrations.

CONCLUSIONS

The third generation Elecsys PTH(1-84) assay had comparable precision performance and correlated well with second generation iPTH assays. However, significant discrepancy was found among the four iPTH assays in measuring iPTH in CKD patients.

Identification of hemoglobin variants in samples received for glycated hemoglobin testing

BACKGROUND

In 2010 Singapore's National Health Survey reported 11.3% of the population between 18-69 years of age with diabetes, compared to 8.2% in 2006. This increasing trend reinforces the dependence on HbA(1c) for management of glycemic control.

METHODS

To determine the incidence of hemoglobin variants received from our diabetic population who are attending the National University Hospital for testing of their HbA(1c) and determine whether the hemoglobin variant caused an interpretation issue, we reviewed all chromatograms from patients sending a sample for HbA(1c) analysis for a three-month period. Analysis was performed on the Variant II using the HbA(2)/HbA(1c) Dual program.

RESULTS

Our sub-analysis identified 2 cases of α thalassemia, 2 cases of β thalassemia; 5 cases of hemoglobin E variant homozygous, 1 case of hemoglobin J variant, 110 cases of hemoglobin E, 7 cases of hemoglobin S, 1 case of hemoglobin C and 1 case of hemoglobin D, all heterozygous. HbA(1c) results could be confidently reported in all cases except the homozygote variant and the hemoglobin J variant.

CONCLUSIONS

Overall we obtained a prevalence of 2.3% of hemoglobin variants in our diabetic population being screened by HbA(1c) using Variant II.

Immunoglobulin-associated creatine kinase masquerading as macro-creatine kinase type 2 in a statin user

Macro-creatine kinase (CK) is a cause of falsely elevated CK. Macro-CK type 1 is immunoglobulin-associated CK; type 2 is polymeric mitochondrial-CK. An elderly asymptomatic lady had an elevated CK level after receiving statin therapy. Her CK gel electrophoresis analysis demonstrated coexisting macro-CK type 1 and type 2 patterns. Further analysis by immunofixation and mixing this patient's serum with CK control material revealed an IgG-associated macro-CK that mimicked the electrophoretic pattern of macro-CK type 2. This highly unusual discovery suggests the possibility of the misinterpretation of macro-CK type 1 as macro-CK type 2. Falsely elevated CK is still common despite modern laboratory instrumentation and should be investigated.

Glycated haemoglobin: what is the diagnostic yield at shortened testing intervals?

The proportion of sequential HbA1c exceeding critical difference (diagnostic yield), where it is considered clinically significant change, was calculated for different testing intervals. 12% and 26% of repeat HbA1c exceeded the critical difference before 30 and 90 days testing intervals, respectively. Repeating HbA1c within 4 weeks has poor diagnostic yield and should be avoided.

Meeting regulatory requirements by the use of cell phone text message notification with autoescalation and loop closure for reporting of critical laboratory results

Critical laboratory results require timely and accurate transmission to the appropriate caregiver to provide intervention to prevent an adverse outcome. We report the use of text messages to notify critical laboratory results in a large teaching hospital to manage the documentation and audit requirements of critical result reporting by regulatory agencies. The text messaging system (critical reportable result health care messaging system [CRR-HMS]) allows a receiver to acknowledge or reject a critical result by short message service reply. Failure to obtain a confirmatory receipt within 10 minutes produces an automated escalation to an alternative physician according to a roster. The median time required for physician response decreased from 7.3 minutes to 2 minutes after implementation of the CRR-HMS. The CRR-HMS is a clinically useful tool to rapidly communicate critical results to targeted physicians to facilitate rapid and timely intervention. This feature seems to be an important laboratory process mediator, and recent Joint Commission reviews have placed this as a requirement.

135 EXPRESSION OF APOPTOSIS-RELATED GENES IN BUFFALO (BUBALUS BUBALIS) EMBRYOS PRODUCED THROUGH IN VITRO FERTILIZATION AND PARTHENOGENETIC ACTIVATION

Apoptosis, a highly conserved evolutionary mechanism that allows an organism to tightly control cell numbers, tissue size, and protect itself from dangerous cells and unfavourable environments that threaten homeostasis, is generally directed by specific genes involved in the regulation of a series of pro-apoptotic (BAX) and anti-apoptotic (BCL-XL) proteins that are expressed during early development. All mammalian species show the highest level of spontaneous apoptotic processes at the blastocyst stage. These proteins prevent apoptosis by maintaining the cell survival by interfering with the release of cytochrome-C from mitochondria. In this study, immature oocytes were obtained from buffalo slaughterhouse ovaries and were subjected to in vitro maturation (IVM) in TCM-199 + 10% FBS + 5 μg mL–1 porcine FSH for 24 h in a CO2 incubator (5% CO2, 90 to 95% relative humidity) at 38.5°C. The mature oocytes were used for IVF, and the cleaved embryos were cultured for 8 days in culture medium (CR2 medium containing 0.6% BSA and 10% FBS) for production of embryos at different stages. The parthenotes were produced with exposure of 7% ethanol, 6-dimethyl aminopurine and cultured for 8 days in culture medium. The total RNA was isolated from oocytes and embryos and transcribed using Cell-to-cDNA-II (Ambion, Austin, TX, USA), according to manufacturer protocol. The PCR cycle included heating to 94°C for 5 min, followed by 35 cycles of 94°C for 30 s, 60 (BAX) and 62°C (BCL) for 30 s, and 72°C for 45 s with a final extension at 72°C for 10 min. The amplified product of both genes were separated on agarose gel and densitometry data for band intensities were generated using AlphaDigiDocTM AD-1201 software under a WindowsTM environment and data analysed with the help of SYSTAT software. Relative abundance of BCL-XL transcripts in immature, mature oocytes and embryos produced through IVF (i.e. 2-cell, 4-cell, 8- to 16-cell, morula, and blastocyst stage) were 25.33 ± 0.90, 12.67 ± 1.20, 37.67 ± 0.90, 30.67 ± 0.30, 23.67 ± 0.90, 18.33 ± 0.90, and 27.00 ± 1.20, respectively, whereas in parthenogenesis these values were 23.67 ± 0.88, 13.67 ± 1.20, 23.67 ± 1.20, 22.34 ± 0.88, 24.34 ± 0.88, 33.67 ± 0.88, and 45.34 ± 1.20, respectively. Relative abundance of BAX transcripts by IVF were 23.0 ± 0.60, 0.33 ± 0.10, 4.00 ± 0.60, 5.00 ± 0.60, 0.37 ± 0.06, 13.0 ± 0.66, and 56.7 ± 0.90; and by parthenonenesis were 22.3 ± 0.90, 0.13 ± 0.03, 13.67 ± 0.90, 14.0 ± 0.60, 15.33 ± 0.90, 64.67 ± 2.20, and 55.0 ± 2.10, respectively. In conclusion, the expression pattern of the apoptosis-related genes revealed that the incidence of apoptosis was significantly higher in IVF and parthenogenetically produced buffalo embryos at stages such as immature oocytes, morula, and blastocyst than the early cleavage stage embryos.

Comparison of the technical and clinical performance of the Elecsys HBsAg II assay with the Architect, AxSym, and Advia Centaur HBsAg screening assays

South East Asia has some of the highest prevalence rates of hepatitis B virus (HBV) infection (>or=8%) in the world, and the emergence of hepatitis B surface antigen (HBsAg) mutant strains is a growing problem. Assays with the highest levels of sensitivity, including mutant detection, should be used for routine HBsAg screening. In this large multicenter study, the clinical and technical performance of the fully automated Elecsys HBsAg II assay was compared with the Architect, AxSYM, and Advia Centaur HBsAg assays for HBsAg screening. Nine laboratories (three each from Thailand, Korea, and Singapore) compared the Elecsys HBsAg II assay with their routine HBsAg screening assay against a range of stored and routine clinical samples, including recombinant mutants. The Elecsys HBsAg II assay demonstrated equivalent sensitivity and specificity to the Architect HBsAg assay. However, the Elecsys HBsAg II assay recognized a native mutant sample (L94S, L97V, L98V, T123A) that the Architect HBsAg assay failed to detect. The AxSYM and Advia Centaur HBsAg assays appeared less sensitive for the detection of early HBV infection and also failed to detect some of the recombinant mutant strains. There was almost complete agreement between the Elecsys HBsAg II assay and comparator assays with respect to routine serum samples. The results of this study demonstrate that the Elecsys HBsAg II assay is a highly sensitive and specific screening assay for HBsAg and detects reliably the most important and clinically relevant HBV mutants and genotypes. It is suitable for routine HBsAg screening in Asia.

The choice of estimating equations for glomerular filtration rate significantly affects the prevalence of chronic kidney disease in a multi-ethnic population during health screening

BACKGROUND

Patients present to the National University Hospital of Singapore and select one of several health screening packages after counselling. The prevalence of chronic kidney disease (CKD) in this population when different glomerular filtration rate (GFR) estimating equations are used has not been examined.

METHODS

Demographic data and urinalyses of patients from 2000 to 2005 were extracted from laboratory computer databases and analysed. CKD was classified into stages according to the US National Kidney Foundation guidelines by eGFR (mL/min per 1.73 m(2)) using the four-variable Modification of Diet in Renal Disease equation. GFR of ethnic Chinese was also estimated using Ma's equation 8 (cGFR). Stage 1 and normal (eGFR or cGFR > 90) was discriminated by urinary microscopy or dipstick for proteinuria, albuminuria, hematuria or leukocyturia.

RESULTS

There were 3979 screenings (55.9% males, 61.9% Chinese). Means: age = 47.0 +/- 12.3 years, creatinine = 80.1 +/- 26.5 micromol/L, eGFR = 89.6 +/- 19.7, cGFR = 110.8 +/- 23.8 and (eGFR + cGFR) = 102.5 +/- 24.9. By eGFR in all patients, the prevalence of CKD was 45.7%, 50.6%, 3.3%, 0.3% and 0.08% for stages normal or 1, 2, 3, 4 and 5, respectively. For Chinese patients only, eGFR and cGFR resulted in a different distribution (eGFR%/cGFR%): 24.9/50.5, 15.2/29.3, 56.8/19.7, 3/0.8, 0.2/0.2, 0/0 for stages 'Normal', 1, 2, 3, 4 and 5, respectively (P < 0.001).

CONCLUSION

The prevalence of moderate to severe CKD (stage 3 to 5) in patients presenting for health screening in Singapore was 3.7%. Notably, the prevalence of mild to moderate CKD (stages 1, 2 and 3) in Chinese patients was affected significantly by the choice of GFR estimating equation.

Combination of 1H nuclear magnetic resonance spectroscopy and liquid chromatography/mass spectrometry with pattern recognition techniques for evaluation of metabolic profile associated with albuminuria

A method using 1H NMR and LC/MS with pattern recognition tools such as principal component analysis (PCA) and orthogonal projection to latent structure discriminant analysis (O-PLS-DA) was used to study the urinary metabolic profiles associated with an increase in urinary albumin in a general population. The normalized peak intensities obtained from 1H NMR and LC/MS with nonparametric two-tailed Mann-Whitney analysis was used for the identification of network of potential biomarkers corresponding to the increase of albumin in urine. The specificity of detecting the stated metabolites by 1H NMR and LC/MS was demonstrated. Our preliminary data obtained demonstrated that LC/MS may produce more distinctive metabolic profiles. For the patient group, changes in alanine, kyneurnic acid, and xanthurenic acid might be associated with changes in the tryptophan metabolism. At the same time, other metabolites that were involved in citric acid cycle, amino acid metabolism, and cellular functions were affected in the patient group. The proposed approach provided a comprehensive picture of the metabolic changes induced by the increase of protein in urine and demonstrated the advantages of using multiple diagnostic biomarkers. At the same time, the current work was demonstrated as a potential cost-effective solution of high-throughput analysis with pattern recognition tools as applied here in a real clinical situation.

Seasonal variation in hemoglobin A1c: is it the same in both hemispheres?

INTRODUCTION

There are several reports from locations in the northern hemisphere of seasonal variation in hemoglobin A1c (HbA1c) levels with higher values noted in the cooler months. The variation has been attributed to holiday seasons, temperature differences, and changes in diet. This article describes the seasonal variation in both hemispheres and in a country on the equator with minimal temperature variation.

METHODS

The mean and median HbA1c by month was calculated for a maximum of 2 years for HbA1c data from the different locations: Edmonton and Calgary, Canada; Singapore; Melbourne, Australia; and Marshfield, Wisconsin. The mean monthly temperature for each location was found from available meteorological information.

RESULTS

In both northern and southern hemispheres, the HbA1c was higher in cooler months and lower in the warmer months. In Singapore, where there is minimal temperature variation, there is also minimal variation in HbA1c values over the year. The difference in HbA1c over a year appears to be related to the difference in temperature.

CONCLUSION

Hemoglobin A1c is higher in cooler months and lower in the warmer months in both hemispheres. In a country with minimal monthly temperature variation, there is only minimal variation in HbA1c values through the year. In all locations, the mean and median HbA1c declined over the study period, possibly due to better glycemic control of patients with diabetes or an increase in use of HbA1c as a screening test for diabetes or a combination of both.

Combined adenocarcinoid and mucinous cystadenoma of the appendix: a case report

INTRODUCTION

Adenocarcinoid of the appendix is a rare malignant tumour with features of both adenocarcinoma and carcinoid, showing both epithelial and endocrine differentiation. Mucinous cystadenoma is the commonest of the benign neoplasms of the appendix, with an incidence of 0.6% in appendicectomy specimens. We report a rare combination of these tumours and discuss the latest treatment options. To the best of our knowledge, only six cases have been reported in the literature to date.

CASE PRESENTATION

A 71-year-old Caucasian man presented to our department with a right iliac fossa mass associated with pain. Laparoscopy revealed an adenocarcinoid of the appendix in combination with mucinous cystadenoma. He underwent a radical right hemicolectomy with clear margins and lymph nodes.

CONCLUSION

Adenocarcinoids account for 2% of primary appendiceal malignancies. Most tumours are less than 2 cm in diameter and 20% of them metastasize to the ovaries. The mean age for presentation is 59 years and the 5-year survival rate ranges from 60% to 84%. Right hemicolectomy is generally advised if any of the following features are present: tumours greater than 2 cm, involvement of resection margins, greater than 2 mitoses/10 high-power fields on histology, extension of tumour beyond serosa. Chemotherapy mostly with 5-Fluorouracil and Leucovorin is advised for remnant disease after surgery. Cytoreductive surgery with intraperitoneal chemotherapy can offer improved survival for advanced peritoneal dissemination.

Severe acute respiratory syndrome without respiratory symptoms or abnormal chest radiograph findings

We report a serologically confirmed case of severe acute respiratory syndrome (SARS) in a 27-year-old health care worker. The patient reported no respiratory complaints, and the findings of serial chest radiographs were normal. This case illustrates the wide spectrum of clinical illness caused by infection with SARS coronavirus.

The effect of the InterLink cannula on fluid flow rates and haemolysis

OBJECTIVE

To examine the effect of the InterLink cannula system (Becton Dickinson, New Jersey, NY, USA) on intravenous fluid flow rates and red blood cell haemolysis.

METHODS

An in vitro study was performed with crystalloid and packed red blood cells run through intravenous catheters of various sizes, with and without the InterLink cannula. Data recorded and analysed included fluid flow rates and plasma free haemoglobin concentration.

RESULTS

The InterLink cannula significantly reduced flow of crystalloid through a 14G catheter (reduction of median flow rate by 0.72 L/h, 12.3%, P < 0.001). There was a reduction of flow of packed red blood cells through a 14G catheter (0.11 L/h) but this was not statistically significant. There was no significant reduction of flow through smaller catheters and no significant effect on red blood cell haemolysis.

CONCLUSIONS

The InterLink cannula reduced flow rates through large diameter intravenous catheters. Because of other factors affecting fluid infusion in vivo this is of minor clinical significance. No increased haemolysis of red blood cells occurred with the InterLink cannula.

Urine laminin and kallikrein, markers of tubulointerstitial damage in experimental protein overload on pre-existing renal damage

We studied the response of urinary protein overload on preexisting tubulointerstitial nephritis (TIN), which was induced in male Sprague Dawley rats by hexachloro-1,3-butadiene (HCBD). Five days after the development of TIN, puromycin aminonucleoside (PAN) was administered to induce urinary protein overload. Urinary laminin and kallikrein were measured. Urine specimens were collected daily for 14 days and on day 21; and tissue specimens were collected on days 1, 4, 7, 10, 14 and 21. Urinalysis was correlated with the renal pathology at the light microscopic level. Laminin excretion was increased on day 4; one day before total protein, indicating damage to the basement membrane. Kallikrein levels also fell early indicating distal tubular damage. There is clear evidence that urine protein overload in a previously damaged kidney with tubulointerstitial injury leads to accelerated and more severe renal damage. Laminin and kallikrein are early and sensitive markers of renal injury.