Effects of Topical Tebufenozide Application to Choristoneura fumiferana Pupae (Lepidoptera: Tortricidae)

Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae) is a defoliating pest in Canada and the northeastern United States. Given its important ecological and economic effects in affected regions, several direct management techniques have been developed, including the application of the insect growth regulator tebufenozide (Mimic™, RH-5992) to feeding larval stages. While the effectiveness of tebufenozide, in this capacity, is understood, management programs of other lepidopteran pests have demonstrated the effectiveness of tebufenozide application when utilized against other life stages. Here, we investigated the toxicity of topically-applied tebufenozide to C. fumiferana pupae to determine if such a strategy could be feasible. We observed significant dose-dependent decreases in the likelihood of adult emergence, increases in the likelihood of pupal death or adult deformity at eclosion, and significant decreases in mean adult longevity. Estimated LD 50 (lethal dose) values for adult male and female C. fumiferana treated as pupae ≤ 4 days after pupation were approximately 1-3 and 2-3.5% ACI (active commercial ingredient) respectively. Estimated L-SD (lethal-sublethal) 50 doses for adult male and female C. fumiferana treated as pupae ≤4 days after pupation were <1, and <2% ACI, respectively. Mating success was also significantly lower in mating pairs containing adults treated as pupae. Although, the amounts required to cause appreciable pupal mortality were much higher than those currently applied operationally in the C. fumiferana system, our study illustrates the potential of tebufenozide to utilized against additional developmental stages in other lepidopteran pests.

Clinical validation of qPCR Target Selector™ assays using highly specific switch-blockers for rare mutation detection

AIMS

The identification of actionable DNA mutations associated with a patient's tumour is critical for devising a targeted, personalised cancer treatment strategy. However, these molecular analyses are typically performed using tissue obtained via biopsy, which involves substantial risk and is often not feasible. In addition, biopsied tissue does not always reflect tumour heterogeneity, and sequential biopsies to track disease progression (eg, emergence of drug resistance mutations) are not well tolerated. To overcome these and other biopsy-associated limitations, we have developed non-invasive 'liquid biopsy' technologies to enable the molecular characterisation of a patient's cancer using peripheral blood samples.

METHODS

The Target Selector ctDNA platform uses a real-time PCR-based approach, coupled with DNA sequencing, to identify cancer-associated genetic mutations within circulating tumour DNA. This is accomplished via a patented blocking approach suppressing wild-type DNA amplification, while allowing specific amplification of mutant alleles.

RESULTS

To promote the clinical uptake of liquid biopsy technologies, it is first critical to demonstrate concordance between results obtained via liquid and traditional biopsy procedures. Here, we focused on three genes frequently mutated in cancer: EGFR (Del19, L858, and T790), BRAF (V600) and KRAS (G12/G13). For each Target Selector assay, we demonstrated extremely high accuracy, sensitivity and specificity compared with results obtained from tissue biopsies. Overall, we found between 93% and 96% concordance to blinded tissue samples across 127 clinical assays.

CONCLUSIONS

The switch-blocker technology reported here offers a highly effective method for non-invasively determining the molecular signatures of patients with cancer.

Admission Laboratory Values Accurately Predict In-hospital Mortality: a Retrospective Cohort Study

BACKGROUND

The greater the severity of illness of a patient, the more likely the patient will have a poor hospital outcome. However, hospital-wide severity of illness scores that are simple, widely available, and not diagnosis-specific are still needed. Laboratory tests could potentially be used as an alternative to estimate severity of illness.

OBJECTIVE

To evaluate the ability of hospital laboratory tests, as measures of severity of illness, to predict in-hospital mortality among hospitalized patients, and therefore, their potential as an alternative method to severity of illness risk adjustment.

DESIGNS AND PATIENTS

A retrospective cohort study among 38,367 adult non-trauma patients admitted to the University of Maryland Medical Center between November 2015 and November 2017 was performed. Laboratory tests (hemoglobin, platelet count, white blood cell count, urea nitrogen, creatinine, glucose, sodium, potassium, and total bicarbonate (HCO₃)) were included when ordered within 24 h from the time of hospital admission. A multivariable logistic regression model to predict in-hospital mortality was constructed using a section of our cohort (n = 21,003).

MAIN MEASURES

Model performance was evaluated using the c-statistic and the Hosmer-Lemeshow (HL) test. In addition, a calibration belt was constructed to determine a confidence interval around the calibration curve with the purpose of identifying ranges of miscalibration.

KEY RESULTS

Patient age and all laboratory tests predicted mortality with good discrimination (c = 0.79). Patients with abnormal HCO₃ levels or leukocyte counts at admission were twice as likely to die during their hospital stay as patients with normal results. A good model calibration and fit were observed (HL = 13.9, p = 0.18).

CONCLUSIONS

Admission laboratory tests are able to predict in-hospital mortality with good accuracy, providing an objective and widely accessible approach to severity of illness risk adjustment.

Rickettsia japonica Infections in Humans, Xinyang, China, 2014-2017

During 2014–2017, we screened for Rickettsia japonica infection in Xinyang, China, and identified 20 cases. The major clinical manifestations of monoinfection were fever, asthenia, myalgia, rash, and anorexia; laboratory findings included thrombocytopenia and elevated hepatic aminotransferase concentrations. Physicians in China should consider R. japonica infection in at-risk patients.

Evaluation of laboratory investigative methods of diagnosing clonal hematological disorders in a resource-poor setting

Background

The successful treatment of patients with clonal hematological disorders (CHDs) depends largely on making an accurate diagnosis, which is, in turn, is dependent on performing specific diagnostic tests that are necessary.

Objectives

This study assessed the laboratory investigative methods of diagnosing CHDs with regard to the specific required tests (SRTs) that were needed to make a final diagnosis in a center with limited resources.

Methods

This is a descriptive hospital-based retrospective study. For the study, data about laboratory investigation details of adults diagnosed with CHDs from 1995 to 2015 were retrieved. The SRTs were determined and data analyzed using SPSS version 20.

Results

A total of 129 case notes of adults in the age range of 18-80 years, diagnosed with CHDs, were used. Out of the 671 SRTs needed for diagnosis, only 304 (45.3%) were conducted. When an SRT was requested to be done within the treatment facility, the patients were significantly more likely to do it in comparison with when they were requested to get it done from an external referral laboratory. All the patients with aplastic anemia (AA) and paroxysmal nocturnal hemoglobinuria (PNH) had all (100%) their SRTs done while patients with non-Hodgkin's lymphoma (NHL) had the least (15.3%) of their SRTs done. Full blood count (FBC) was the most frequently used (n = 129; 100%) SRT for diagnosis while immunophenotyping (IMPT) was the least (n = 4; 8.3%) used SRT.

Conclusion

Most of our patients had CHD diagnosis without the complete SRT, and this may cast doubt on the accuracy of diagnosis. Therefore, there is a crucial need for availability of more comprehensive laboratory services, especially in government-owned hospitals.

Fasting-Evoked En Route Hypoglycemia in Diabetes (FEEHD): From Guidelines to Clinical Practice

BACKGROUND

Lipid profiles have been used for the purposes of health screening and monitoring of the effects of lipid-lowering medications, especially in patients with diabetes who are prone to hyperlipidemia. Fasting for lipid profiles has been the norm for the past decades. This long-lasting tradition poses a risk of hypoglycemia, especially in patients with diabetes.

OBJECTIVE

Our aim is to review the overlooked occurrence of hypoglycemia in patients who fast for laboratory tests, especially lipid profile tests, and commute to the laboratory facility while fasting; a condition we titled "Fasting-Evoked En route Hypoglycemia in Diabetes patients" or "FEEHD". We also review its prevalence and clinical impact on patients with diabetes.

METHODS

We undertook an extensive literature search using search engines such as PubMed and Google Scholar. We used the following keywords for the search: Fasting, Non-fasting; Hypoglycemia; Hypoglycemic Agents; Laboratory Tests; Glucose, Hypoglycemia, Lipid Profiles, FEEHD.

RESULTS

Our literature review has shown that the prevalence of FEEHD is alarmingly high (17-21% of patients at risk). This form of hypoglycemia is under recognized in the clinical practice despite its frequent occurrence. Recent changes in various international guidelines have uniformly endorsed the utilization of non-fasting lipid profiles as the new standard for obtaining lipid profiles with the exception of certain conditions. Multiple studies showed the efficacy of non-fasting lipid tests in comparison to fasting lipid tests, in routine clinical practice.

CONCLUSION

We hope to increase awareness among clinicians about this overlooked and potentially harmful form of hypoglycemia in patients with diabetes, which can be easily avoided. We also hope to call upon clinicians to consider changing the habit of ordering lipid profiles in the fasting state, which has been recently shown to be largely unnecessary in routine clinical settings, with few exceptions in selected cases.

[Development and implementation of Single Reference Laboratory Testing Directory, as the basis for the digitalization of the laboratory service of Moscow]

Authors considered the possibilities and limitations of EMIAS implementation in the laboratory service of the city of Moscow on the example of the development and implementation of an integrated Single Reference Laboratory Testing Directory (SRLTD). The article describes the analytical and methodological work performed to systematize the nomenclature when creating the directory. The advantages of SRLTD are assessed: new opportunities for further digitalization of the city's laboratory service, streamlining of medical documentation, convenience in obtaining laboratory data from doctors and patients, and the expected economic effect.

Preference of saliva over other body fluids as samples for clinical and laboratory investigations among healthcare workers in Ibadan, Nigeria

Introduction

The study aimed to assess the knowledge and practices of clinicians and laboratory scientists on the use of saliva for clinical or laboratory tests.

Methods

This was a cross-sectional survey of health care workers (100 clinicians and 62 laboratory scientists) closely involved with specimen collection for clinical and laboratory investigation at two health facilities (secondary and tertiary) in Nigeria. Information was obtained from participants using pretested structured questionnaires. Data were analyzed with SPSS and level of significance set at p < 5%.

Results

The mean age of the study participants was 34.1 (±6.6) years. The majority (95.7%) knew saliva could be used for clinical/laboratory test. A higher proportion of laboratory scientists knew saliva could be used in diagnosing HIV (59.2%), oral diseases (88.7%), oro-facial tumors (64.4%) and genetic testing (94.5%) compared to (41%), (80%), (40%) and (80%), of clinicians respectively (p < 0.05). More clinicians (85%) indicated saliva as a good specimen for diagnosing systemic diseases compared with scientists (63%), p < 0.001. Saliva was the most comfortable/convenient body fluid to obtain from patients with more clinicians (80%) mentioning this than scientists (49.1%), p < 0.001. Twenty-six clinicians had used saliva for disease diagnosis (64%), treatment monitoring (28%) or research purposes (8%). Saliva sampling for research purposes was more prevalent among clinicians (p = 0.004).

Conclusion

The majority of the health care workers knew the various uses and advantages of saliva as a specimen for clinical and laboratory investigation. However, few indicated previous use for clinical and laboratory investigation especially in the area of research.

Expert Recommendations on Frequency of Utilization of Common Laboratory Tests in Medical Inpatients: a Canadian Consensus Study

BACKGROUND

Repetitive inpatient laboratory testing in the face of clinical stability is a marker of low-value care. However, for commonly encountered clinical scenarios on medical units, there are no guidelines defining appropriate use criteria for laboratory tests.

OBJECTIVE

This study seeks to establish consensus-based recommendations for the utilization of common laboratory tests in medical inpatients.

DESIGN

This study uses a modified Delphi method. Participants completed two rounds of an online survey to determine appropriate testing frequencies for selected laboratory tests in commonly encountered clinical scenarios. Consensus was defined as agreement by at least 80% of participants.

PARTICIPANTS

Participants were 36 experts in internal medicine across Canada defined as internists in independent practice for ≥ 5 years with experience in medical education, quality improvement, or both. Experts represented 8 of the 10 Canadian provinces and 13 of 17 academic institutions.

MAIN MEASURES

Laboratory tests and clinical scenarios included were those that were considered common on medical units. The final survey contained a total of 45 clinical scenarios looking at the utilization of six laboratory tests (complete blood count, electrolytes, creatinine, urea, international normalized ratio, and partial thromboplastin time). The possible frequency choices were every 2-4 h, 6-8 h, twice a day, daily, every 2-3 days, weekly, or none unless there was specific diagnostic suspicion. These scenarios were reviewed by two internists with training in quality improvement and survey methods.

KEY RESULTS

Of the 45 initial clinical scenarios included, we reached consensus on 17 scenarios. We reached weak consensus on an additional 19 scenarios by combining two adjacent frequency categories.

CONCLUSIONS

A Canadian expert panel of internists has provided frequency recommendations on the utilization of six common laboratory tests in medical inpatients. These recommendations need validation in prospective studies to assess whether restrictive versus liberal laboratory test ordering impacts patient outcomes.

Inflammation throughout pregnancy and fetal growth restriction in rural Nepal

Maternal systemic inflammation during pregnancy may restrict embryo−fetal growth, but the extent of this effect remains poorly established in undernourished populations. In a cohort of 653 maternal−newborn dyads participating in a multi-armed, micronutrient supplementation trial in southern Nepal, we investigated associations between maternal inflammation, assessed by serum α₁-acid glycoprotein and C-reactive protein, in the first and third trimesters of pregnancy, and newborn weight, length and head and chest circumferences. Median (IQR) maternal concentrations in α₁-acid glycoprotein and C-reactive protein in the first and third trimesters were 0.65 (0.53–0.76) and 0.40 (0.33–0.50) g/l, and 0.56 (0.25–1.54) and 1.07 (0.43–2.32) mg/l, respectively. α₁-acid glycoprotein was inversely associated with birth size: weight, length, head circumference and chest circumference were lower by 116 g (P = 2.3 × 10⁻⁶), and 0.45 (P = 3.1 × 10⁻⁵), 0.18 (P = 0.0191) and 0.48 (P = 1.7 × 10⁻⁷) cm, respectively, per 50% increase in α₁-acid glycoprotein averaged across both trimesters. Adjustment for maternal age, parity, gestational age, nutritional and socio-economic status and daily micronutrient supplementation failed to alter any association. Serum C-reactive protein concentration was largely unassociated with newborn size. In rural Nepal, birth size was inversely associated with low-grade, chronic inflammation during pregnancy as indicated by serum α₁-acid glycoprotein.

Interpreting clinical and laboratory tests: importance and implications of context

Clinical and laboratory tests in clinical medicine include a range of measurements that may be categorized as "normal range" tests, positive or negative tests, or contextual tests. Normal range test results are quantitative and are compared to a reference interval or range provided by the laboratory. Positive or negative tests are also quantitative tests and characteristically have a cutoff value that specifies the result. Contextual tests require a context, a physiological condition, to correctly interpret the result. A closer examination of reference intervals suggests that these also are contextual. The fact that there is a range of apparently normal values indicates the presence of cultural, biological, physiological and behavioral diversity in the population sampled to determine normality. As such, the reference interval describes the population from which it was determined and may have utility in this regard.

Investigation and management of subfertility

Subfertility affects one in seven couples and is defined as the inability to conceive after 1 year of regular unprotected intercourse. This article describes the initial clinical evaluation and investigation to guide diagnosis and management. The primary assessment of subfertility is to establish the presence of ovulation, normal uterine cavity and patent fallopian tubes in women, and normal semen parameters in men. Ovulation is supported by a history of regular menstrual cycles (21-35 days) and confirmed by a serum progesterone >30 nmol/L during the luteal phase of the menstrual cycle. Common causes of anovulation include polycystic ovary syndrome (PCOS), hypothalamic amenorrhoea (HA) and premature ovarian insufficiency (POI). Tubal patency is assessed by hysterosalpingography, hystero-contrast sonography, or more invasively by laparoscopy and dye test. The presence of clinical or biochemical hyperandrogenism, serum gonadotrophins (luteinising hormone/follicle stimulating hormone) / oestradiol, pelvic ultrasound to assess ovarian morphology / antral follicle count, can help establish the cause of anovulation. Ovulation can be restored in women with PCOS using letrozole (an aromatase inhibitor), clomifene citrate (an oestrogen antagonist) or exogenous gonadotrophin administration. If available, pulsatile gonadotrophin releasing hormone therapy is the preferred option for restoring ovulation in HA. Spermatogenesis can be induced in men with hypogonadotrophic hypogonadism with exogenous gonadotrophins. Unexplained subfertility can be treated with in vitro fertilisation after 2 years of trying to conceive. Involuntary childlessness is associated with significant psychological morbidity; hence, expert assessment and prompt treatment are necessary to support such couples.

Prevalence and impact of abnormal routine pre-operative test results among elective surgical patients with or without co-morbidity: An observational comparative study

Background

At present, selective and clinical assessment-based pre-operative investigations are advocated, but it is yet far from routine practice.

Aim

This study aims to assess the prevalence and impact of abnormal routine pre-operative test results among co-morbid and non-co-morbid elective surgical patients.

Methods

Data for this prospective study were collected by reviewing the medical charts of the patients attending pre-anaesthetic clinic from December 2016 to April 2017. The cohort was divided into non-co-morbid and co-morbid. Routine pre-operative tests were done, their results and impacts of abnormal test results were noted; number needed to investigate (NNI) was calculated. Data were compared using Fisher's exact test, unpaired t-test, etc., P < 0.05 was considered statistically significant.

Results

Data from 887 patients; 322 (36.30%) co-morbid were analysed. Co-morbid patients were older (53.79 ± 14.99 vs. 40.33 ± 15.68 year). No difference was found in the number of tests done in co-morbid patients except significantly higher number of electrocardiogram and echocardiography (P < 0.0001). Abnormal test results were significantly higher among co-morbid (relative risk - 1.63, P < 0.0001). Impacts were similar in co-morbid as compared to non-co-morbid for most of the tests, but thyroid function and blood sugar tests showed NNI for significant impact below 10 in co-morbid group.

Conclusion

Co-morbid patients have more abnormal results than non-co-morbid patients, but impacts of such tests are nearly indifferent. Routine testing is not favourable even in co-morbid patients. Selective or co-morbid disease-specific tests are having more significant impacts and should replace the 'routine testing' even in co-morbid patients.

Relationship of Estimated GFR and Albuminuria to Concurrent Laboratory Abnormalities: An Individual Participant Data Meta-analysis in a Global Consortium

RATIONALE & OBJECTIVE

Chronic kidney disease (CKD) is complicated by abnormalities that reflect disruption in filtration, tubular, and endocrine functions of the kidney. Our aim was to explore the relationship of specific laboratory result abnormalities and hypertension with the estimated glomerular filtration rate (eGFR) and albuminuria CKD staging framework.

STUDY DESIGN

Cross-sectional individual participant-level analyses in a global consortium.

SETTING & STUDY POPULATIONS

17 CKD and 38 general population and high-risk cohorts.

SELECTION CRITERIA FOR STUDIES

Cohorts in the CKD Prognosis Consortium with data for eGFR and albuminuria, as well as a measurement of hemoglobin, bicarbonate, phosphorus, parathyroid hormone, potassium, or calcium, or hypertension.

DATA EXTRACTION

Data were obtained and analyzed between July 2015 and January 2018.

ANALYTICAL APPROACH

We modeled the association of eGFR and albuminuria with hemoglobin, bicarbonate, phosphorus, parathyroid hormone, potassium, and calcium values using linear regression and with hypertension and categorical definitions of each abnormality using logistic regression. Results were pooled using random-effects meta-analyses.

RESULTS

The CKD cohorts (n=254,666 participants) were 27% women and 10% black, with a mean age of 69 (SD, 12) years. The general population/high-risk cohorts (n=1,758,334) were 50% women and 2% black, with a mean age of 50 (16) years. There was a strong graded association between lower eGFR and all laboratory result abnormalities (ORs ranging from 3.27 [95% CI, 2.68-3.97] to 8.91 [95% CI, 7.22-10.99] comparing eGFRs of 15 to 29 with eGFRs of 45 to 59mL/min/1.73m2), whereas albuminuria had equivocal or weak associations with abnormalities (ORs ranging from 0.77 [95% CI, 0.60-0.99] to 1.92 [95% CI, 1.65-2.24] comparing urinary albumin-creatinine ratio > 300 vs < 30mg/g).

LIMITATIONS

Variations in study era, health care delivery system, typical diet, and laboratory assays.

CONCLUSIONS

Lower eGFR was strongly associated with higher odds of multiple laboratory result abnormalities. Knowledge of risk associations might help guide management in the heterogeneous group of patients with CKD.

Do doctors who order more routine medical tests diagnose more cancers? A population-based study from Ontario Canada

Background

The overuse of medical tests leads to higher costs, wasting of resources, and the potential for overdiagnosis of disease. This study was designed to determine whether the patients of family doctors who order more routine medical tests are diagnosed with more cancers.

Method

A retrospective population‐based cross‐sectional study using administrative health care data in Ontario Canada. We investigated the ordering of 23 routine laboratories and imaging tests 2008‐20012 by 6849 Ontario family physicians on their 4.9 million rostered adult patients. We compared physicians’ test utilization and calculated case‐mix adjusted observed to expected (O:E) utilization ratios to categorize physicians as Typical, Higher or Lower testers. Age‐sex standardized rates (cases/10 000 patient years) and Rate Ratios were determined for cancers of the thyroid, prostate, breast, lymphoma, kidney, melanoma, uterus, ovary, lung, esophagus, and pancreas for each tester group.

Results

There was wide variation in the use of the 23 tests by Ontario physicians. 26% and 24% of physicians were deemed Higher Testers for laboratory and imaging tests, while 41% and 38% were Typical Testers. The patients of higher test users were diagnosed with more cancers of thyroid (laboratory [RR 1.61, 95% CI 1.39‐1.87] and imaging [RR 2.08, 95% CI 0.88‐2.30]) and prostate (laboratory [RR 1.10, 95% CI 1.03‐1.18] and imaging [RR 1.05, 95% CI 1.00‐1.10]).

Conclusion

There is a wide variation in the ordering of routine and common medical tests among Ontario family doctors. The patients of higher testers were diagnosed with more thyroid and prostate cancers.

JAK2-tree: a simple CBC-based decision rule to guide appropriate JAK2 V617F mutation testing

Aims

The JAK2 V617F mutation is highly recurrent in many of the myeloproliferative neoplasms, a molecular variant that can be easily detected using sensitive and minimally invasive techniques. Given the ease of JAK2 V617F testing, this test may be improperly requested for the purposes of patient ‘screening’ and to optimise laboratory resource utilisation, it behooves clinicians and laboratorians to perform JAK2 V617F testing only when most appropriate.

Methods

To assist with the screening of patients being considered for JAK2 V617F testing, we developed a clinical decision rule, “JAK2-tree”, which can be easily applied to basic CBC parameters (haemoglobin, platelet and white blood cell counts).

Results

We tested JAK2-tree on two independent datasets, one an unselected population-based sample (the Copenhagen General Population Study) and the other an historical clinical laboratory referral set, with sensitivities for JAK2 V617F detection of 91% and 94%, respectively. As applied to the historical laboratory referral dataset, moreover, the JAK2-tree algorithm would have reduced JAK2 V617F testing volume over the period of evaluation by 15%.

Conclusions

Our work supports a simple decision-tree-based screening approach to optimize the selection of patients most appropriate for JAK2 V617F testing.

Laboratory Evaluation of a Commercially Available Rapid Syphilis Test

Serological diagnosis of syphilis depends on assays that detect treponemal and nontreponemal antibodies. Laboratory certification and trained personnel are needed to perform most of these tests, while high costs and long turnaround time can hinder treatment initiation or linkage to care. A rapid treponemal syphilis test (RST) that is simple to perform, accessible, and inexpensive would be ideal. The Syphilis Health Check (SHC) assay is the only Food and Drug Administration (FDA)-cleared and Clinical Laboratory Improvement Amendments (CLIA)-waived RST in the United States. In this study, 1,406 archived human serum samples were tested using SHC and traditional treponemal and nontreponemal assays. Rapid test results were compared with treponemal data alone and with a laboratory test panel consensus defined as being reactive by both treponemal and nontreponemal assays for a given specimen, or nonreactive by both types of assays. The sensitivity and specificity of the SHC assay compared with treponemal tests alone were 88.7% (95% confidence interval [CI], 86.2 to 90.0%) and 93.1% (95% CI, 90.0 to 94.9%), respectively, while comparison with the laboratory test panel consensus showed 95.7% (95% CI, 93.6 to 97.2%) sensitivity and 93.2% (95% CI, 91.0 to 95.1%) specificity. The data were further stratified based on age, sex, pregnancy, and HIV status. The sensitivity and specificity of the SHC assay ranged from 66.7% (95% CI, 46.0 to 83.5%) to 91.7% (95% CI, 87.7 to 94.7%) and 88% (95% CI, 68.8 to 97.5%) to 100% (95% CI, 47.8 to 100%), respectively, across groups compared to traditional treponemal assays, generally increasing for all groups except the HIV-positive (HIV+) population when factoring in the laboratory test panel consensus. These data contribute to current knowledge of the SHC assay performance for distinct populations and may guide use in various settings.

Predicting anti-Kell-mediated hemolytic disease of the fetus and newborn: diagnostic accuracy of laboratory management

BACKGROUND

There is controversy on critical cut-off values of laboratory testing to select pregnancies at increased risk for anti-Kell-mediated hemolytic disease of the fetus and newborn. Without early detection and treatment, anti-Kell-mediated hemolytic disease of the fetus and newborn may result in progressive fetal anemia, fetal hydrops, asphyxia, and perinatal death.

OBJECTIVE

We aimed to determine the value of repeated anti-Kell titer determination and biological activity measurement using the antibody-dependent cellular cytotoxicity test determination in the management of pregnancies at risk for anti-Kell-mediated hemolytic disease of the fetus and newborn.

STUDY DESIGN

This was a retrospective cohort study of pregnancies with anti-Kell and a Kell-positive fetus, identified from January 1999 through April 2015. Laboratory test results and clinical outcome were collected from the Dutch nationwide screening program and the national reference center for fetal therapy in The Netherlands, the Leiden University Medical Center. Diagnostic accuracy was measured (receiver operating characteristic curves, sensitivity, specificity, positive and negative predictive values) for anti-Kell titers and antibody-dependent cellular cytotoxicity test. The relationship between the titer and antibody-dependent cellular cytotoxicity measurements and the 2 foregoing measurements were computed with a Pearson product-moment correlation coefficient.

RESULTS

In a 16-year unselected cohort, representing screening results of 3.2 million pregnancies resulting in live births in The Netherlands, we identified 1026 Kell-immunized pregnancies. In all, 93 pregnant women had anti-Kell and a Kell-positive child, without other red cell alloantibodies. In all, 49 children (53%) needed intrauterine or postnatal transfusion therapy. The first anti-Kell titer showed already a high diagnostic accuracy with an area under the curve of 91%. The optimal cut-off point for the titer was 4 (sensitivity 100%; 95% confidence interval, 91-100), specificity 27% (95% confidence interval, 15-43), and positive predictive value 60% (49-71%). The antibody-dependent cellular cytotoxicity test was not informative to select high-risk pregnancies. Linear regression showed no significant change during pregnancy, when antibody titer and antibody-dependent cellular cytotoxicity test results were compared with every 2 foregoing measurements (P < .0001).

CONCLUSION

Early determination of the anti-Kell titer is sufficient to select pregnancies at increased risk for hemolytic disease of the fetus and newborn with need for transfusion therapy. If the Kell status of the fetus is known to be positive, a titer of ≥4 can be used to target intensive clinical monitoring.

Frequencies and patterns of laboratory test requests from general practice: a service evaluation to inform point-of-care testing

AIMS

The demand for test requests from general practice to laboratory services remains high. Tests performed at the point of care could reduce turnaround time and speed up clinical decision making. Replicating laboratory testing in the community would require panels of tests to be performed simultaneously, which is now approaching technological feasibility. We assessed frequencies and combinations of test requests from community settings to inform the potential future development of multiplex point-of-care panels.

METHODS

We assessed all laboratory test requests made from general practice in Oxfordshire, UK, from January 2014 to March 2017. We summarised test request frequency overall and in combination, using heatmaps and hierarchical cluster analysis. Results are also presented by age/sex subgroups. We further assessed patterns of tests requested within 7 and 14 days after an initial test request.

RESULTS

11 763 473 test requests were made for 413 073 individuals (28% age >65). Of more than 500 test types, 62 were requested at least 5000 times, most commonly renal function tests (approximately 296 000/year), full blood count (278 000/year) and liver function tests (237 000/year). Cluster analysis additionally identified a clear grouping of tests commonly used to investigate anaemia. Follow-up test frequency was much lower than the frequency of multiple tests ordered at initial presentation.

CONCLUSIONS

The current high volume of single and combination test requests highlights an opportunity for reliable multiplex point-of-care panels to cover a core set of frequently requested tests. The impact on test use of introducing such panels to general practice requires additional research.

How patients navigate the diagnostic ecosystem in a fragmented health system: a qualitative study from India

Background: Depending on a country’s diagnostic infrastructure, patients and providers play different roles in ensuring that correct and timely diagnosis is made. However, little is known about the work done by patients in accessing diagnostic services and completing the ‘test and treat’ loop.

Objective: To address this knowledge gap, we traced the diagnostic journeys of patients with tuberculosis, diabetes, hypertension and typhoid, and examined the work they had to do to arrive at a diagnosis.

Methods: This paper draws on a qualitative study, which included 78 semi-structured interviews and 13 focus group discussions with patients, public and private healthcare providers, community health workers, test manufacturers, laboratory technicians, program managers and policymakers. Data were collected between January and June 2013 in rural and urban Karnataka, South India, as part of a larger project on barriers to point-of-care testing. We reconstructed patient diagnostic processes retrospectively and analyzed emerging themes and patterns.

Results: The journey to access diagnostic services requires a high level of involvement and immense work from patients and/or their caretakers. This process entails overcoming cost and distance, negotiating social relations, continuously making sense of their illness and diagnosis, producing and transporting samples, dealing with the social consequences of diagnosis, and returning results to the treating provider. The quality and content of interactions with providers were crucial for completion of test and treat loops. If the tasks became overwhelming, patients opted out, delayed being tested, switched providers and/or reverted to self-testing or self-treatment practices.

Conclusion: Our study demonstrated how difficult it can be for patients to complete diagnostic journeys and how the health system works as far as diagnostics are concerned. If new point-of-care tests are to be implemented successfully, policymakers, program officers and test developers need to find ways to ease patient navigation through diagnostic services.

Assessment of the Stability of von Willebrand Profile Clotting Factors and Platelet Dense Granule Testing Following Air Transport

The purpose of this study was to determine the reliability of test results dependent upon blood and plasma sample stability when shipped by airfreight courier for reference laboratory assessment. Of particular interest was evaluation of von Willebrand profile assays and platelet dense granule storage pool analysis. Peripheral venous blood was obtained from healthy volunteers. von Willebrand factor (VWF) activity, VWF antigen, and factor VIII coagulant activity assays were performed immediately following venipuncture with additional aliquots of plasma frozen and stored at −70°C for subsequent analysis 48 hours later. One frozen aliquot was shipped via airfreight for analysis 48 hours later, with another frozen aliquot that remained on-site. Blood was also collected to enumerate platelet dense granules to determine whether shipment would affect results. Statistical analysis of all test results demonstrated significant correlation between immediately assayed samples and samples that were stored for 48 hours at −70°C (P < .0001), or frozen and shipped on dry ice (P < .0001) for analysis upon return to our laboratory. No difference was found in the mean number of platelet dense granules between samples retained in our laboratory or samples analyzed upon return of shipment (P = .751).

Biologics monitoring: incongruity between recommendations and clinician monitoring trends

Background: Biologics are commonly used for moderate to severe psoriasis. Monitoring laboratory tests may provide little definitive benefit to patients.Objective: We queried a Humana database to gain insight regarding dermatologists' laboratory monitoring practices for psoriasis patients on biologics.Methods: Data were obtained from the Humana database. Our cohort included 333 patients with primary ICD-9 diagnosis of psoriasis (696.1) between the years 2008 and 2013 who are prescribed any biologic medication. Subjects on methotrexate, acitretin, or cyclosporine were excluded from the study. We separately queried laboratory tests by CPT codes and quantified based on frequency over a 2-year time period. Percentages of demographic group receiving a laboratory test at a given frequency category were calculated.Results: About 46% and 47% of patients received >4 comprehensive metabolic panel and complete blood count tests 2 years after starting a biologic. About 18% of individuals age >50 received greater than four Basic Metabolic Panel tests 2 years after starting a biologic.Limitations: Patient comorbidities might confound some of our findings, as these laboratory tests may have been ordered for a comorbidity rather than for biologics side effect monitoring.Conclusions: There are inconsistencies between current monitoring practices and guidelines. Clarifying biologics monitoring recommendations in psoriasis patients may reduce healthcare costs and provider workload.

NT-proBNP Predicts All-Cause Mortality in a Population of Insurance Applicants, Follow-up Analysis and Further Observations

OBJECTIVE

- Further refine the independent value of NT-proBNP, accounting for the impact of other test results, in predicting all-cause mortality for individual life insurance applicants with and without heart disease.

METHOD

- Using the Social Security Death Master File and multivariate analysis, relative mortality was determined for 245,322 life insurance applicants ages 50 to 89 tested for NT-proBNP (almost all based on age and policy amount) along with other laboratory tests and measurement of blood pressure and BMI.

RESULTS

- NT-proBNP values ≤75 pg/mL included the majority of applicants denying heart disease and had the lowest risk, while values >500 pg/mL for females and >300 pg/mL for males had very high relative risk. Those admitting to heart disease had a higher mortality risk for each band of NT-proBNP relative to those denying heart disease but had a similar and equally predictive risk curve.

CONCLUSION

- NT-proBNP is a strong independent predictor of all-cause mortality in the absence or presence of known heart disease but the range of values associated with increased risk varies by sex.

Abnormal routine pre-operative test results and their impact on anaesthetic management: An observational study

BACKGROUND AND AIMS

One of the reasons for continued routine pre-operative testing practice is the identification of hidden problems which may affect perioperative management. This study was aimed to assess the prevalence of abnormal test results, their impact on perioperative management and cost-effectiveness for detecting such abnormalities.

METHODS

This observational study was conducted by screening the files of the patients attending pre-anaesthetic check-up during December 2016-January 2017. Patients' physical status, surgery grade, normal and abnormal test results and different impacts were noted and expressed in absolute numbers/percentage. Number needed to investigate (NNI) to detect a significant abnormality was calculated.

RESULTS

Data of 414 patients (46.3% male) with mean ± standard deviation age 43.78 ± 17.24 years and 58.65 ± 12.93 kg weight were analysed. Patients were mostly American Society of Anesthesiologists II and underwent National Institute of Clinical and Health Excellence Grade 3 surgeries. Totally, 345 (11.6%) test results were abnormal. Only 56 (16.2%) abnormalities had an impact in terms of referral, further investigations or delay. Twenty were significant in terms of changing perioperative anaesthetic management. Laboratory abnormalities with non-significant impact resulted in median delay of 3 days (range 1 to 12 days). The NNI for a significant impact and detecting new abnormality was 21 and 28, respectively.

CONCLUSION

Majority (57.2%) of the patients had at least one abnormal routine test result but only 1.8% abnormalities had significant impact. The NNI to find a significant impact or hidden comorbidity was more than 20.