FIT negative clinic as a safety net for low-risk patients with colorectal cancer: impact on endoscopy and radiology utilisation-a retrospective cohort study

Background

Faecal immunochemical testing (FIT) is recommended by the National Institute for Health and Care Excellence to triage symptomatic primary care patients who have unexplained symptoms but do not meet the criteria for a suspected lower gastrointestinal cancer pathway. During the COVID-19 pandemic, FIT was used to triage patients referred with urgent 2-week wait (2ww) cancer referrals instead of a direct-to-test strategy. FIT-negative patients were assessed and safety netted in a FIT negative clinic.

Methods

We reviewed case notes for 622 patients referred on a 2ww pathway and seen in a FIT negative clinic between June 2020 and April 2021 in a tertiary care hospital. We collected information on demographics, indication for referral, dates for referral, clinic visit, investigations and long-term outcomes.

Results

The average age of the patients was 71.5 years with 54% female, and a median follow-up of 2.5 years. Indications for referrals included: anaemia (11%), iron deficiency (24%), weight loss (9%), bleeding per rectum (5%) and change in bowel habits (61%). Of the cases, 28% (95% CI 24% to 31%) had endoscopic (15%, 95% CI 12% to 18%) and/or radiological (20%, 95% CI 17% to 23%) investigations requested after clinic review, and among those investigated, malignancy rate was 1.7%, with rectosigmoid neuroendocrine tumour, oesophageal cancer and lung adenocarcinoma.

Conclusion

A FIT negative clinic provides a safety net for patients with unexplained symptoms but low risk of colorectal cancer. These real-world data demonstrate significantly reduced demand on endoscopy and radiology services for FIT-negative patients referred via the 2ww pathway.

Severe acute myositis and myocarditis on initiation of 6-weekly pembrolizumab post-COVID-19 mRNA vaccination

We describe three cases of critical acute myositis with myocarditis occurring within 22 days of each other at a single institution, all within 1 month of receiving the initial cycle of the anti-PD-1 drug pembrolizumab. Analysis of T cell receptor repertoires from peripheral blood and tissues revealed a high degree of clonal expansion and public clones between cases, with several T cell clones expanded within the skeletal muscle putatively recognizing viral epitopes. All patients had recently received a COVID-19 mRNA booster vaccine prior to treatment and were positive for SARS-CoV2 Spike antibody. In conclusion, we report a series of unusually severe myositis and myocarditis following PD-1 blockade and the COVID-19 mRNA vaccination.

Copeptin and the syndrome of inappropriate antidiuresis (SIAD) after pituitary transsphenoidal surgery

OBJECTIVE

This study evaluates the predictive value of copeptin for syndrome of inappropriate antidiuresis (SIAD) postpituitary transsphenoidal surgery (TSS).

DESIGN

Data from 133 consecutive patients undergoing TSS (November 2017-October 2022) at Oxford University Hospitals NHS trust are presented in this retrospective study.

METHODS

Logistic regression (LR) and receiver operating characteristic (ROC) curves were performed to evaluate the diagnostic utility of copeptin. The Mann-Whitney U test was used to compare copeptin levels between the SIAD and no SIAD groups.

RESULTS

Fourteen patients (10.8%) developed SIAD. Copeptin was available in 121, 53 and 87 patients for Days 1, 241 and 8 post-TSS, respectively. LR for Day 1 copeptin to predict SIAD gave an odds ratio (OR) of 1.0 (95%CI 42 0.84-1.20, p = .99), area under-ROC curve (AUC) was 0.49; Day 2 copeptin OR was 0.65 (95%CI 0.39-1.19, 43 p = .77), AUC was 0.57 LR for Day 1 sodium to predict SIAD gave an odds ratio (OR) of 1.0 (95%CI 0.85-1.21, p = .99), AUC was 0.50.

CONCLUSIONS

In conclusion, our data provide no evidence for copeptin as a predictive marker for post-TSS SIAD.

Trends in diagnostic tests ordered for children: a retrospective analysis of 1.7 million laboratory test requests in Oxfordshire, UK from 2005 to 2019

OBJECTIVE

To better understand testing patterns in children, we measured temporal trends in paediatric testing from 2005 to 2019 in Oxfordshire, UK.

DESIGN

Descriptive study of population-based secondary data.

SETTING

Oxfordshire University Hospitals National Health Service Trust laboratories.

PARTICIPANTS

Children aged 0-15 years in Oxfordshire who received at least one blood test.

MAIN OUTCOME MEASURES

We estimated average annual percentage changes (AAPCs) in test use using joinpoint regression models. Temporal changes in age-adjusted rates in test use were calculated overall and stratified by healthcare setting, sex, and age.

RESULTS

Between 2005 and 2019, 1 749 425 tests were performed among 113 607 children. Overall test use declined until 2012, when test rates appeared to increase (AAPC 1.5%, 95% CI -0.8% to 3.9%). Most tests were performed in inpatient settings, where testing rates stayed steady (AAPC -0.6%, 95% CI -2.1% to 0.9%). Increases were highest in females, those aged 6-15 years and in the outpatient setting. The greatest increase in testing was for vitamin D (AAPC 26.5%), followed by parathyroid hormone (9.8%), iron studies (9.3%), folate (8.4%), vitamin B12 (8.4%), HbA1c (8.0%), IgA (7.9%) and coeliac (7.7%).

CONCLUSIONS

After an initial decline, laboratory test use by children in Oxfordshire demonstrated an apparent increase since 2012. Test use increased in outpatient and general practice settings, however remained steady in inpatient settings. Further research should examine the root causes and implications for test increases, and whether these increases are warranted. We encourage clinicians to consider the individual and systemic implications of performing blood tests in children.

Characterisation of parathyroid hormone concentration in extremely preterm or very low birthweight infants in routine clinical screening for metabolic bone disease: A service evaluation cohort study

AIM

To characterise parathyroid hormone (PTH) concentrations in infants at high risk for metabolic bone disease, in order to assist clinical decisions around the use of PTH for screening.

METHODS

Infants born under 28 weeks' postmenstrual age or with birthweight under 1.5 kg in a tertiary neonatal unit in the UK were included. Clinical guidance was to assess PTH concentration in the first 3 weeks after birth. Clinical information was extracted from prospective records.

RESULTS

Sixty-four infants had mean birth gestation of 26 weeks and birthweight of 882 g. Median PTH (sent on median day 18 of life) was 9.2 pmol/L (interquartile range 5.3-17 pmol/L). Sixty-seven per cent of infants had a PTH greater than 7 pmol/L. For 22% of the infants, raised PTH was not accompanied by abnormal phosphate or alkaline phosphatase. Eighty-nine per cent of infants tested were insufficient or deficient for 25-hydroxyvitamin D.

CONCLUSIONS

Universal screening highlights the high frequency of high PTH in this high-risk population, implying a need for calcium supplementation. A considerable number of infants would not be identified as showing potential signs of metabolic bone disease if the assessment excludes the use of PTH. The high level of 25-hydroxyvitamin D deficiency may be a confounder.

Assessing treatment adherence is crucial to determine adequacy of mineralocorticoid therapy

Background

There is no consensus strategy for mineralocorticoid (MC) therapy titration in patients with primary adrenal insufficiency (PAI). We aim to measure serum fludrocortisone (sFC) and urine fludrocortisone (uFC) levels and to determine their utility, alongside clinical/biochemical variables and treatment adherence to guide MC replacement dose titration.

Methods

Multi-centre, observational, cross-sectional study on 41 patients with PAI on MC replacement therapy. sFC and uFC levels (measured by liquid chromatography-tandem mass spectrometry), plasma renin concentration (PRC), electrolytes (Na+, K+), mean arterial blood pressure (MAP), total daily glucocorticoid (dGC) and MC (dMC) dose, and assessment of treatment adherence were incorporated into statistical models.

Results

We observed a close relationship between sFC and uFC (r = 0.434, P = 0.005) and between sFC and the time from the last fludrocortisone dose (r = -0.355, P = 0.023). Total dMC dose was related to dGC dose (r = 0.556, P < 0.001), K+ (r = -0.388, P = 0.013) as well as sFC (r = 0.356, P = 0.022) and uFC (r = 0.531, P < 0.001). PRC was related to Na+ (r = 0.517, P < 0.001) and MAP (r = -0.427, P = 0.006), but not to MC dose, sFC or uFC. Regression analyses did not support a role for sFC, uFC or PRC measurements and confirmed K+ (B = -44.593, P = 0.005) as the most important variable to guide dMC titration. Of the patients, 32% were non-adherent with replacement therapy. When adherence was inserted into the regression model, it was the only factor affecting dMC.

Conclusions

sFC and uFC levels are not helpful in guiding dMC titration. Treatment adherence impacts on clinical variables used to assess MC replacement and should be included as part of routine care in patients with PAI.

Evaluation of a Simple Low-cost Intervention to Empower People with CKD to Reduce Their Dietary Salt Intake: OxCKD1, a Multicenter Randomized Controlled Trial

Key Points

A randomized controlled trial demonstrates that a simple and cheap 1-month intervention empowers people with CKD to lower their dietary salt intake. The effect of the intervention persisted after the intervention finished.

Background

To evaluate the efficacy of a simple low-cost intervention to empower people with CKD to reduce their dietary salt intake.

Methods

A randomized controlled trial in primary and secondary care comparing the OxSalt care bundle intervention versus standard care for 1 month. Participants were people with CKD and an eGFR >20 ml/min per 1.73 m2 and were recruited from primary and secondary care. The primary outcome was a reduction in dietary salt intake, as assessed by 24-hour urinary sodium excretion, after 1 month of the intervention.

Results

Two hundred and one participants were recruited. Dietary salt intake, as assessed from 24-hour urine sodium excretion, fell by 1.9 (±2.9) g/d in the intervention group compared with 0.4 (±2.7) g/d in the control group (P < 0.001). Salt intake was still reduced to a lesser extent over the following year in the intervention group.

Conclusions

A short, low-cost, easily delivered intervention empowers people with CKD to reduce their dietary salt intake.

Trial registration

ClinicalTrials.gov NCT01552317 .

Post-pituitary surgery copeptin analysis as a 'rule-out' test for post-operative diabetes insipidus

BACKGROUND

Diabetes insipidus (DI) is a recognised complication of pituitary surgery, with diagnosis requiring clinical observation aided by plasma and urine electrolytes and osmolalities. Copeptin is a stable surrogate marker of AVP release and has potential to facilitate prompt diagnosis of post-operative DI. This assay has been shown to accurately predict which patients are likely to develop DI following pituitary surgery.

OBJECTIVE

To determine whether copeptin analysis can be used to predict which patients are at risk of developing DI following trans-sphenoidal surgery (TSS).

METHODS

Seventy-eight patients undergoing TSS had samples taken for copeptin pre-operatively and at day 1 post-TSS. The majority of patients also had samples from day 2, day 8, and week 6 post-TSS. Results from patients who developed post-operative DI (based on clinical assessment, urine and plasma biochemistry and the need for treatment with DDAVP) were compared to those who did not. Patients with any evidence of pre-operative DI were excluded.

RESULTS

Of 78 patients assessed, 11 were clinically determined to have developed DI. Differences were observed between patients with DI and those without in post-operative samples. Of note, there was a significant difference in plasma copeptin at day 1 post-operation (p = 0.010 on Kruskal-Wallis test), with copeptin levels greater than 3.4 pmol/l helping to rule out DI (91% sensitivity, 55% specificity at this cut off).

CONCLUSION

In the post-TSS setting, copeptin is a useful rule-out test in patients with values above a defined threshold, which may facilitate earlier decision making and shorter hospital stays.

UK Reference Intervals for Parathyroid Hormone Using Abbott Methods

Background: Diagnosis of hyperparathyroidism requires measurement of parathyroid hormone (PTH) in the context of the plasma calcium and other factors, such as vitamin D status and renal function. Accurate classification depends upon an appropriate population reference interval. We examined local population plasma PTH reference intervals at four different UK sites using a common platform. Methods: Plasma PTH results were extracted from laboratory information systems at four different UK sites, all using the Abbott Architect i2000 method. We included only people with normal adjusted serum calcium, magnesium, vitamin D, and renal function. Following outlier rejection lower and upper reference limits were derived. Results: An overall reference interval for plasma PTH of 3.0-13.7 pmol/L was observed using a non-parametric approach compared to 2.9-14.1 pmol/L using a parametric approach, notably higher than the manufacturer's representative range of 1.6-7.2 pmol/L. We also noted statistically significant differences (p < 0.00001) between some sites with upper limits ranging from 11.5 to 15.8 pmol/L which may be due to different population characteristics of each group. Conclusion: Locally derived reference intervals may be beneficial for UK populations and revised upper thresholds are necessary when using the Abbott PTH method to avoid inappropriate classification of patients as having hyperparathyroidism.

How should we interpret lactate in labour? A reference study

OBJECTIVE

To investigate maternal lactate concentrations in labour and the puerperium.

DESIGN

Reference study.

SETTING

Tertiary obstetric unit.

POPULATION

1279 pregnant women with good perinatal outcomes at term.

METHODS

Electronic patient records were searched for women who had lactate measured on the day of delivery or in the following 24 hours, but who were subsequently found to have a very low likelihood of sepsis, based on their outcomes.

MAIN OUTCOME MEASURES

The normative distribution of lactate and C-reactive protein (CRP), differences according to the mode of birth, and the proportion of results above the commonly used cut-offs (≥2 and ≥4 mmol/l).

RESULTS

Lactate varied between 0.4-5.4 mmol/l (median 1.8 mmol/l, interquartile range [IQR] 1.3-2.5). It was higher in women who had vaginal deliveries than caesarean sections (median 1.9 vs. 1.6 mmol/l, p_diff  < 0.001), demonstrating the association with labour (particularly active pushing in the second stage). In contrast, CRP was more elevated in women who had caesarean sections (median 71.8 mg/l) than those who had vaginal deliveries (33.4 mg/l, p_diff  < 0.001). In total, 40.8% had a lactate ≥2 mmol/l, but 95.3% were <4 mmol/l.

CONCLUSIONS

Lactate in labour and the puerperium is commonly elevated above the levels expected in healthy pregnant or non-pregnant women. There is a paucity of evidence to support using lactate or CRP to make decisions about antibiotics around the time of delivery but, as lactate is rarely higher than 4 mmol/l, this upper limit may still represent a useful severity marker for the investigation and management of sepsis in labour.

IL7 genetic variation and toxicity to immune checkpoint blockade in patients with melanoma

Treatment with immune checkpoint blockade (ICB) frequently triggers immune-related adverse events (irAEs), causing considerable morbidity. In 214 patients receiving ICB for melanoma, we observed increased severe irAE risk in minor allele carriers of rs16906115, intronic to IL7. We found that rs16906115 forms a B cell-specific expression quantitative trait locus (eQTL) to IL7 in patients. Patients carrying the risk allele demonstrate increased pre-treatment B cell IL7 expression, which independently associates with irAE risk, divergent immunoglobulin expression and more B cell receptor mutations. Consistent with the role of IL-7 in T cell development, risk allele carriers have distinct ICB-induced CD8+ T cell subset responses, skewing of T cell clonality and greater proportional repertoire occupancy by large clones. Finally, analysis of TCGA data suggests that risk allele carriers independently have improved melanoma survival. These observations highlight key roles for B cells and IL-7 in both ICB response and toxicity and clinical outcomes in melanoma.

The potential for utilising in-hospital glucose measurements to detect individuals at high risk of previously undiagnosed diabetes: Retrospective cohort study

BACKGROUND

Many people with undiagnosed diabetes have hyperglycaemia when admitted to hospital. Inpatient hyperglycaemia can be an indication of diabetes mellitus but can also indicate a stress response. This study reports the extent to which an in-hospital maximum observed random glucose measurement is an indicator of the need for in-hospital (or subsequent) HbA1c measurement to look for undiagnosed diabetes.

METHODS

Blood glucose, HbA1c, age and sex were collected for all adults following admission to a UK NHS trust hospital from 1 January 2019 to 31 December 2020. We restricted the analysis to those participants who were registered with a GP practice that uses the trust laboratory and who had at least some tests requested by those practices since 2008. We stratified individuals according to their maximum in-hospital glucose measurement and report the number of these with HbA1c measurement ≥48 mmol/mol (6.5%) prior to the index admission, and during and after admission. We calculated an estimated proportion of individuals in each blood glucose stratum without a follow-up HbA1c who could have undiagnosed diabetes.

RESULTS

In toal, 764,241 glucose measurements were recorded for 81,763 individuals who were admitted to the Oxford University Hospitals Trust. The median (Q1, Q3) age was 70 (56, 81) years, and 53% were males. Of the population, 70.7% of individuals declared themselves to be of White ethnicity, 3.1% of Asian background, and 1.1% of Black background, with 23.1% unstated. Of those individuals, 22,375 (27.4%) had no previous HbA1c measurement recorded. A total of 1689 individuals had a diabetes-range HbA1c during or after their hospital admission (2.5%) while we estimate an additional 1496 (2.2%) may have undiagnosed diabetes, with the greatest proportion of these having an in-hospital glucose of ≥15 mmol/L. We estimate that the number needed to detect a possible new case of diabetes falls from 16 (in-hospital glucose 8 mmol/L to <9 mmol/L) to 4 (14 mmol/L to <15 mmol/L).

CONCLUSION

The number of people who need to be tested to identify an individual who may have diabetes decreases as a testing threshold based on maximum in-hospital glucose concentration increases. Among those with hyperglycaemia and no previous HbA1c measurement in the diabetes range, there appears to be a lack of subsequent HbA1c measurement. This work identifies the potential for integrating the testing and follow-up of people, with apparently unrecognised hospital hyperglycaemia across primary and secondary care.

Reduction in Chest CT Severity and Improved Hospital Outcomes in SARS-CoV-2 Omicron Compared with Delta Variant Infection

Background The SARS-Cov-2 Omicron variant demonstrates rapid spread but reduced disease severity. Studies evaluating lung imaging findings of Omicron infection versus non-Omicron infection remain lacking. Purpose To compare the Omicron variant with the SARS-CoV-2 Delta variant according to their chest CT radiologic pattern, biochemical parameters, clinical severity, and hospital outcomes after adjusting for vaccination status. Materials and Methods This retrospective study included hospitalized adult patients with reverse transcriptase-polymerase chain reaction test results positive for SARS-CoV-2, with CT pulmonary angiography performed within 7 days of admission between December 1, 2021, and January 14, 2022. Multiple readers performed blinded radiologic analyses that included RSNA CT classification, chest CT severity score (CTSS) (range, 0 [least severe] to 25 [most severe]), and CT imaging features, including bronchial wall thickening. Results A total of 106 patients (Delta group, n = 66; Omicron group, n = 40) were evaluated (overall mean age, 58 years ± 18 [SD]; 58 men). In the Omicron group, 37% of CT pulmonary angiograms (15 of 40 patients) were categorized as normal compared with 15% (10 of 66 patients) of angiograms in the Delta group (P = .016). A generalized linear model was used to control for confounding variables, including vaccination status, and Omicron infection was associated with a CTSS that was 7.2 points lower than that associated with Delta infection (β = -7.2; 95% CI: -9.9, -4.5; P < .001). Bronchial wall thickening was more common with Omicron infection than with Delta infection (odds ratio [OR], 2.4; 95% CI: 1.01, 5.92; P = .04). A booster shot was associated with a protective effect for chest infection (median CTSS, 5; IQR, 0-11) when compared with unvaccinated individuals (median CTSS, 11; IQR, 7.5-14.0) (P = .03). The Delta variant was associated with a higher OR of severe disease (OR, 4.6; 95% CI: 1.2, 26; P = .01) and admission to a critical care unit (OR, 7.0; 95% CI: 1.5, 66; P = .004) when compared with the Omicron variant. Conclusion The SARS-CoV-2 Omicron variant was associated with fewer and less severe changes on chest CT images compared with the Delta variant. Patients with Omicron infection had greater frequency of bronchial wall thickening but less severe disease and improved hospital outcomes when compared with patients with Delta infection. © RSNA, 2022 Online supplemental material is available for this article.

POS1549-HPR IMPROVING EFFICACY AND SAFETY OF BLOOD MONITORING IN RHEUMATOLOGY PATIENTS ON DISEASE MODIFYING ANTI-RHEUMATIC DRUGS (DMARDs) USING A NEW AUTOMATED ALGORITHM

Background

Most patients in Rheumatology require early management with DMARDs to control their disease. In our department, around two hundred patients start a DMARD therapy every month and monitoring their blood test results whilst on DMARDs play an essential role to detect toxicity and the need for further action. This process has been done manually, which has been prone to error. Over the past six months, a minimum of three patients have had abnormalities which were missed, consequently identifying the need to improve the quality of the blood monitoring.

Objectives

The aim of the project was to develop, test and implement an automated algorithm to review multiple blood test results and highlight any changes, trends or abnormalities in patients starting DMARD therapy efficiently.

Methods

We designed a system to automatically review blood tests from patients newly started on DMARD therapy, following the recommended British Society for Rheumatology (BSR) schedule for blood monitoring. Results are processed in our local laboratory, subsequently uploaded to our unique database and analysed automatically using an algorithm against BSR guided threshold values for each blood test. According to the value, each blood result is identified as normal, mildly abnormal, missing, trending, or abnormal. A trained clinician or pharmacist will review the data and endorse the results after taking any appropriate action. Based on the results, if any actions are needed, patients are contacted either by phone or via a letter automatically generated by this software, recommending them to have a repeat test or temporarily stop the medication as required.

Results

The system was tested on two cohorts, comprised of 100 and 227 blood tests. It was faster and more efficient than the manual alternative. Following this test, each record was compared manually, based on the data stored on a spreadsheet.

This new system led to the identification of more abnormalities versus the manual inspection (29% vs 10%, Chi square P<0.001). Additionally, it took less than a minute compared to the manual method, which took three hours to complete. Follow up manual inspection confirmed that the new system had correctly identified every abnormality, based on test records.

To date, we have analysed 3568 blood results using this technique. 1564 (44%) results have been normal and endorsed within seconds. 374 (10%) were mildly abnormal, 17 (0.5%) results have been abnormal requiring action and 311 (9%) were abnormal requiring no action. 265 (7%) results showed a trend within the blood results. Trending results were defined as being out of range and worsening on two consecutive occasions but not reaching the limits for stoppig a drug. 1032 (29%) results contained missing results, a consequence of the different timings of results uploaded by various laboratory sections.

Conclusion

We have developed an efficient and safe blood monitoring system for Rheumatology patients starting on a DMARD, proven to be more accurate compared to previous manual alternatives and able to process up to 10,000 results at a time.

Disclosure of Interests

None declared

Combining faecal immunochemical testing with blood test results for colorectal cancer risk stratification: a consecutive cohort of 16,604 patients presenting to primary care

BACKGROUND

Faecal immunochemical tests (FITs) are used to triage primary care patients with symptoms that could be caused by colorectal cancer for referral to colonoscopy. The aim of this study was to determine whether combining FIT with routine blood test results could improve the performance of FIT in the primary care setting.

METHODS

Results of all consecutive FITs requested by primary care providers between March 2017 and December 2020 were retrieved from the Oxford University Hospitals NHS Foundation Trust. Demographic factors (age, sex), reason for referral, and results of blood tests within 90 days were also retrieved. Patients were followed up for incident colorectal cancer in linked hospital records. The sensitivity, specificity, positive and negative predictive values of FIT alone, FIT paired with blood test results, and several multivariable FIT models, were compared.

RESULTS

One hundred thirty-nine colorectal cancers were diagnosed (0.8%). Sensitivity and specificity of FIT alone at a threshold of 10 μg Hb/g were 92.1 and 91.5% respectively. Compared to FIT alone, blood test results did not improve the performance of FIT. Pairing blood test results with FIT increased specificity but decreased sensitivity. Multivariable models including blood tests performed similarly to FIT alone.

CONCLUSIONS

FIT is a highly sensitive tool for identifying higher risk individuals presenting to primary care with lower risk symptoms. Combining blood test results with FIT does not appear to lead to better discrimination for colorectal cancer than using FIT alone.

Improving diagnostic accuracy in pregnancy with individualised, gestational age-specific reference intervals

BACKGROUND AND AIMS

Investigations in pregnancy should be interpreted using pregnancy-specific reference intervals (RIs). However, because of the progressive nature of pregnancy, even pregnancy-specific RIs may not be equally representative at different gestations. We proposed that gestational age-specific RIs may increase diagnostic accuracy over those with fixed limits.

MATERIALS AND METHODS

The trajectory of platelets was mapped in 32,778 pregnant women, using 116,798 results. Then we evaluated the accuracy with which a low measurement in early pregnancy (<3^rd centile) predicted thrombocytopaenia at term, compared to the existing limit (<150 x10⁹/L).

RESULTS

Platelets fell by 14.8% between 8-40 weeks. Platelets below the 3^rd centile before 20 weeks predicted thrombocytopaenia at term (<100 x10⁹/L) with a significantly greater degree of accuracy than a fixed limit (AUC 0.86 vs. 0.76, p=0.004).

CONCLUSION

Pregnancy-specific RIs can be defined using routinely collected hospital data, and the abundance of such freely available data enables a detailed investigation of temporal changes throughout gestation. Individualised RIs offer improved accuracy profiles, over and above those already derived specifically from pregnant populations. Clinicians should consider how this may be used to improve diagnostic accuracy for biomarkers used in current clinical practice, and those yet to be defined.

White blood cells in pregnancy: reference intervals for before and after delivery

BACKGROUND

White blood cells (WBC) are commonly measured to investigate suspected infection and inflammation in pregnant women, but the pregnancy-specific reference interval is variably reported, increasing diagnostic uncertainty in this high-risk population. It is essential that clinicians can interpret WBC results in the context of normal pregnant physiology, given the huge global burden of infection on maternal mortality.

METHODS

We performed a longitudinal, repeated measures population study of 24,318 pregnant women in Oxford, UK, to map the trajectory of WBC between 8-40 weeks of gestation. We defined 95% reference intervals (RI) for total WBC, neutrophils, lymphocytes, eosinophils, basophils, and monocytes for the antenatal and postnatal periods.

FINDINGS

WBC were measured 80,637 times over five years. The upper reference limit for total WBC was elevated by 36% in pregnancy (RI 5.7-15.0×109/L), driven by a 55% increase in neutrophils (3.7-11.6×109/L) and 38% increase in monocytes (0.3-1.1×109/L), which remained stable between 8-40 weeks. Lymphocytes were reduced by 36% (1.0-2.9×109/L), while eosinophils and basophils were unchanged. Total WBC was elevated significantly further from the first day after birth (similar regardless of the mode of delivery), which resolved to pre-delivery levels by an average of seven days, and to pre-pregnancy levels by day 21.

INTERPRETATION

There are marked changes in WBC in pregnancy, with substantial differences between cell subtypes. WBC are measured frequently in pregnant women in obstetric and non-obstetric settings, and results should be interpreted using a pregnancy-specific RI until delivery, and between days 7-21 after childbirth.

FUNDING

None.

Parenchymal involvement on CT pulmonary angiography in SARS-CoV-2 Alpha variant infection and correlation of COVID-19 CT severity score with clinical disease severity and short-term prognosis in a UK cohort

AIM

To determine if there is a difference in radiological, biochemical, or clinical severity between patients infected with Alpha-variant SARS-CoV-2 compared with those infected with pre-existing strains, and to determine if the computed tomography (CT) severity score (CTSS) for COVID-19 pneumonitis correlates with clinical severity and can prognosticate outcomes.

MATERIALS AND METHODS

Blinded CTSS scoring was applied to 137 hospital patients who had undergone both CT pulmonary angiography (CTPA) and whole-genome sequencing of SARS-CoV-2 within 14 days of CTPA between 1/12/20–5/1/21.

RESULTS

There was no evidence of a difference in imaging severity on CTPA, viral load, clinical parameters of severity, or outcomes between Alpha and preceding variants. CTSS on CTPA strongly correlates with clinical and biochemical severity at the time of CTPA, and with patient outcomes. Classifying CTSS into a binary value of “high” and “low”, with a cut-off score of 14, patients with a high score have a significantly increased risk of deterioration, as defined by subsequent admission to critical care or death (multivariate hazard ratio [HR] 2.76, p<0.001), and hospital length of stay (17.4 versus 7.9 days, p<0.0001).

CONCLUSION

There was no evidence of a difference in radiological severity of Alpha variant infection compared with pre-existing strains. High CTSS applied to CTPA is associated with increased risk of COVID-19 severity and poorer clinical outcomes and may be of use particularly in settings where CT is not performed for diagnosis of COVID-19 but rather is used following clinical deterioration.

Long-term monitoring in primary care for chronic kidney disease and chronic heart failure: a multi-method research programme

Background

Long-term monitoring is important in chronic condition management. Despite considerable costs of monitoring, there is no or poor evidence on how, what and when to monitor. The aim of this study was to improve understanding, methods, evidence base and practice of clinical monitoring in primary care, focusing on two areas: chronic kidney disease and chronic heart failure.

Objectives

The research questions were as follows: does the choice of test affect better care while being affordable to the NHS? Can the number of tests used to manage individuals with early-stage kidney disease, and hence the costs, be reduced? Is it possible to monitor heart failure using a simple blood test? Can this be done using a rapid test in a general practitioner consultation? Would changes in the management of these conditions be acceptable to patients and carers?

Design

Various study designs were employed, including cohort, feasibility study, Clinical Practice Research Datalink analysis, seven systematic reviews, two qualitative studies, one cost-effectiveness analysis and one cost recommendation.

Setting

This study was set in UK primary care.

Data sources

Data were collected from study participants and sourced from UK general practice and hospital electronic health records, and worldwide literature.

Participants

The participants were NHS patients (Clinical Practice Research Datalink: 4.5 million patients), chronic kidney disease and chronic heart failure patients managed in primary care (including 750 participants in the cohort study) and primary care health professionals.

Interventions

The interventions were monitoring with blood and urine tests (for chronic kidney disease) and monitoring with blood tests and weight measurement (for chronic heart failure).

Main outcome measures

The main outcomes were the frequency, accuracy, utility, acceptability, costs and cost-effectiveness of monitoring.

Results

Chronic kidney disease: serum creatinine testing has increased steadily since 1997, with most results being normal (83% in 2013). Increases in tests of creatinine and proteinuria correspond to their introduction as indicators in the Quality and Outcomes Framework. The Chronic Kidney Disease Epidemiology Collaboration equation had 2.7% greater accuracy (95% confidence interval 1.6% to 3.8%) than the Modification of Diet in Renal Disease equation for estimating glomerular filtration rate. Estimated annual transition rates to the next chronic kidney disease stage are ≈ 2% for people with normal urine albumin, 3–5% for people with microalbuminuria (3–30 mg/mmol) and 3–12% for people with macroalbuminuria (> 30 mg/mmol). Variability in estimated glomerular filtration rate-creatinine leads to misclassification of chronic kidney disease stage in 12–15% of tests in primary care. Glycaemic-control and lipid-modifying drugs are associated with a 6% (95% confidence interval 2% to 10%) and 4% (95% confidence interval 0% to 8%) improvement in renal function, respectively. Neither estimated glomerular filtration rate-creatinine nor estimated glomerular filtration rate-Cystatin C have utility in predicting rate of kidney function change. Patients viewed phrases such as ‘kidney damage’ or ‘kidney failure’ as frightening, and the term ‘chronic’ was misinterpreted as serious. Diagnosis of asymptomatic conditions (chronic kidney disease) was difficult to understand, and primary care professionals often did not use ‘chronic kidney disease’ when managing patients at early stages. General practitioners relied on Clinical Commissioning Group or Quality and Outcomes Framework alerts rather than National Institute for Health and Care Excellence guidance for information. Cost-effectiveness modelling did not demonstrate a tangible benefit of monitoring kidney function to guide preventative treatments, except for individuals with an estimated glomerular filtration rate of 60–90 ml/minute/1.73 m2, aged < 70 years and without cardiovascular disease, where monitoring every 3–4 years to guide cardiovascular prevention may be cost-effective. Chronic heart failure: natriuretic peptide-guided treatment could reduce all-cause mortality by 13% and heart failure admission by 20%. Implementing natriuretic peptide-guided treatment is likely to require predefined protocols, stringent natriuretic peptide targets, relative targets and being located in a specialist heart failure setting. Remote monitoring can reduce all-cause mortality and heart failure hospitalisation, and could improve quality of life. Diagnostic accuracy of point-of-care N-terminal prohormone of B-type natriuretic peptide (sensitivity, 0.99; specificity, 0.60) was better than point-of-care B-type natriuretic peptide (sensitivity, 0.95; specificity, 0.57). Within-person variation estimates for B-type natriuretic peptide and weight were as follows: coefficient of variation, 46% and coefficient of variation, 1.2%, respectively. Point-of-care N-terminal prohormone of B-type natriuretic peptide within-person variability over 12 months was 881 pg/ml (95% confidence interval 380 to 1382 pg/ml), whereas between-person variability was 1972 pg/ml (95% confidence interval 1525 to 2791 pg/ml). For individuals, monitoring provided reassurance; future changes, such as increased testing, would be acceptable. Point-of-care testing in general practice surgeries was perceived positively, reducing waiting time and anxiety. Community heart failure nurses had greater knowledge of National Institute for Health and Care Excellence guidance than general practitioners and practice nurses. Health-care professionals believed that the cost of natriuretic peptide tests in routine monitoring would outweigh potential benefits. The review of cost-effectiveness studies suggests that natriuretic peptide-guided treatment is cost-effective in specialist settings, but with no evidence for its value in primary care settings.

Limitations

No randomised controlled trial evidence was generated. The pathways to the benefit of monitoring chronic kidney disease were unclear.

Conclusions

It is difficult to ascribe quantifiable benefits to monitoring chronic kidney disease, because monitoring is unlikely to change treatment, especially in chronic kidney disease stages G3 and G4. New approaches to monitoring chronic heart failure, such as point-of-care natriuretic peptide tests in general practice, show promise if high within-test variability can be overcome.

Future work

The following future work is recommended: improve general practitioner–patient communication of early-stage renal function decline, and identify strategies to reduce the variability of natriuretic peptide.

Study registration

This study is registered as PROSPERO CRD42015017501, CRD42019134922 and CRD42016046902.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 9, No. 10. See the NIHR Journals Library website for further project information.

Pregnancy-specific Reference Intervals for BNP and NT-pro BNP-Changes in Natriuretic Peptides Related to Pregnancy

Context

Cardiac disease is the leading cause of maternal mortality in the UK, so accurate cardiovascular diagnoses in pregnancy are essential. BNP (B-type natriuretic peptide) and NT-pro BNP (N-terminal-pro BNP) are useful clinical tools for investigating suspected peripartum cardiomyopathy but, as the pregnancy-specific reference intervals are undefined, it is uncertain how they should be interpreted in pregnant women.

Objectives

To define trimester-specific 95% reference intervals for BNP and NT-pro BNP in pregnancy.

Methods

Longitudinal study of 260 healthy pregnant women, with sampling in each trimester.

Results

The upper reference limit for NT-pro BNP was 200 pg/mL in the first and second trimesters, and 150 pg/mL in the third. Levels were significantly reduced in overweight women in the third trimester (P = .0001), which supports the partitioning of reference intervals by body mass index (BMI). The upper limit for BNP was 50 pg/mL, with no detectable trimester-related differences. Although other biomarkers (hemoglobin and platelets) fell throughout pregnancy, both natriuretic peptides were initially elevated before falling by the third trimester, suggesting that the observed changes in natriuretic peptides are driven by dynamic interplay between cardiac strain and progressive hemodilution. NT-pro BNP in the first trimester was inversely associated with neonatal birthweight at term (P = .011).

Conclusion

Cardiac biomarkers have an important role for investigating suspected disease in high-risk pregnant women, but a robust assessment of the levels expected in healthy pregnant women is an essential prerequisite to their application in clinical practice. This study has defined trimester- and BMI-specific reference intervals for NT-pro BNP and BNP, which may improve how women with suspected cardiovascular disease are investigated in pregnancy.

Faecal immunochemical testing (FIT): sources of result variation based on three years of routine testing of symptomatic patients in English primary care

Introduction: We aimed to determine the analytical capabilities of a commonly used faecal immunochemical test (FIT) to detect faecal haemoglobin (Hb) in symptomatic people attending primary care in the context of the English NICE DG30 guidance.Materials and Methods: Data obtained from independent verification studies and clinical testing of the HM-JACKarc FIT method in routine primary care practice were analysed to derive performance characteristics.Results: Detection capabilities for the FIT method were 0.5 µg/g (limit of blank), 1.3 µg/g (limit of detection) and 3.0 µg/g (limit of quantitation). Of 33 non-homogenized specimens, 31 (93.9%) analysed in triplicate were consistently categorized relative to 10 µg/g, compared to all 33 (100%) homogenized specimens. Imprecision was higher (median 27.8%, (range 20.5% to 48.6%)) in non-homogenized specimens than in homogenized specimens (10.2%, (7.0 to 13.5%)). Considerable variation was observed in sequential clinical specimens from individual patients but no positive or negative trend in specimen degradation was observed over time (p = 0.26).Discussion: The FIT immunoassay evaluated is capable of detecting faecal Hb at concentrations well below the DG30 threshold of 10 µg/g and is suitable for application in this context. The greatest practical challenge to FIT performance is reproducible sampling, the pre-analytical step associated with most variability. Further research should focus on reducing sampling variability, particularly as post-COVID-19 guidance recommends greater FIT utilization.

Cardiac-specific troponins in uncomplicated pregnancy and pre-eclampsia: A systematic review

Background

The risk of myocardial infarction (MI) increases during pregnancy, particularly in women with pre-eclampsia. MI is diagnosed by measuring high blood levels of cardiac-specific troponin (cTn), although this may be elevated in women with pre-eclampsia without MI, which increases diagnostic uncertainty. It is unclear how much cTn is elevated in uncomplicated and complicated pregnancy, which may affect whether the existing reference intervals can be used in pregnant women. Previous reviews have not investigated high-sensitivity troponin in pregnancy, compared to older, less sensitive methods.

Methods

Electronic searches using the terms “troponin I” or “troponin T”, and “pregnancy”, “pregnancy complications” or “obstetrics”. cTn levels were extracted from studies of women with uncomplicated pregnancies or pre-eclampsia.

Results

The search identified ten studies with 1581 women. Eight studies used contemporary methods that may be too insensitive to use reliably in this clinical setting. Two studies used high-sensitivity assays, with one reporting an elevation in troponin I (TnI) in pre-eclampsia compared to uncomplicated pregnancy, and the other only examining women with pre-eclampsia.

Seven studies compared cTn between women with pre-eclampsia or uncomplicated pregnancy using any assay. Seven studies showed elevated TnI in pre-eclampsia compared to uncomplicated pregnancy or non-pregnant women. One study measured troponin T (TnT) in pregnancy but did not examine pre-eclampsia.

Conclusion

TnI appears to be elevated in pre-eclampsia, irrespective of methodology, which may reflect the role of cardiac stress in this condition. TnI may be similar in healthy pregnant and non-pregnant women, but we found no literature reporting pregnancy-specific reference intervals using high-sensitivity tests. This limits broader application of cTn in pregnancy. There is a need to define reference intervals for cTn in pregnant women, which should involve serial sampling throughout pregnancy, with careful consideration for gestational age and body mass index, which cause dynamic changes in normal maternal physiology.

Pregnancy-specific reference intervals for C-reactive protein improve diagnostic accuracy for infection: A longitudinal study

BACKGROUND AND AIMS

Infections are a major cause of maternal mortality. C-reactive protein (CRP), a commonly-used inflammatory marker, is widely used to inform diagnosis, but the upper limit of normal in pregnancy is uncertain. We have defined trimester-specific reference intervals for CRP and evaluated their diagnostic accuracy for infection.

MATERIALS AND METHODS

Development cohort: longitudinal study of pregnant women to determine 95% reference intervals. Evaluation cohort: diagnostic accuracy study to evaluate these intervals in 50 women with suspected intrauterine infection.

RESULTS

In these 322 healthy pregnant women, CRP was substantially higher than in most non-pregnant populations. CRP was similar in each trimester, with an upper reference limit of 19 mg/L. CRP increased linearly with body mass index (p < 0.0001). The sensitivity and specificity of CRP for diagnosing chorioamnionitis were 73% and 86%, respectively. The overall diagnostic accuracy using the pregnancy-specific reference interval was significantly better than that of the existing standard (p = 0.03).

CONCLUSIONS

CRP is a widely-used clinical tool in pregnancy, and a pregnancy-specific reference interval should be used to optimise diagnostic accuracy. Chorioamnionitis was used as an example of a localised infection with well-defined outcomes, but pregnancy-specific RIs for CRP should be considered in any clinical setting including pregnant women.

Faecal immunochemical testing for adults with symptoms of colorectal cancer attending English primary care: a retrospective cohort study of 14 487 consecutive test requests

BACKGROUND

Faecal immunochemical testing (FIT) is recommended by the National Institute for Health and Care Excellence (NICE) to triage symptomatic primary care patients for further investigation of colorectal cancer.

AIM

To ascertain the diagnostic performance of FIT in symptomatic adult primary care patients.

METHODS

Faecal samples from routine primary care practice in Oxfordshire, UK were analysed using the HM-JACKarc FIT method between March 2017 and March 2020. Clinical details were recorded. Patients were followed for up to 36 months in linked hospital records for evidence of benign and serious (colorectal cancer, high-risk adenomas and bowel inflammation) colorectal disease. The diagnostic accuracy of FIT is reported by gender, age group and FIT threshold.

RESULTS

In 9896 adult patients with at least 6-month follow-up, a FIT result ≥10 µg Hb/g faeces had a sensitivity for colorectal cancer of 90.5% (95% CI 84.9%-96.1%), specificity 91.3% (90.8%-91.9%), positive predictive value (PPV) 10.1% (8.15%-12.0%) and negative predictive value (NPV) 99.9% (99.8%-100.0%). The PPV and specificity for serious colorectal disease were higher and the sensitivity and NPV lower than for colorectal cancer alone. The area under the curve for all adults did not change substantially by gender or by increasing the minimum age of testing. Using ≥10 µg Hb/g faeces, 10% of adults would be investigated to detect 91% of cancers, a number needed to scope of ten to detect one cancer. Using ≥7, ≥50 and ≥150 µg Hb/g faeces, 11%, 4% and 3% of adults would be investigated, and 91%, 74% and 54% cancers detected, respectively.

CONCLUSION

A FIT threshold of ≥10 µg Hb/g faeces would be appropriate to triage adult patients presenting to primary care with symptoms of serious colorectal disease. FIT may be used to reprioritise patients referred with colorectal cancer symptoms whose investigations have been delayed by the COVID-19 pandemic.

Random 'spot' urinary metanephrines compared with 24-h-urinary and plasma results in phaeochromocytomas and paragangliomas

BACKGROUND

In patients with phaeochromocytomas or paragangliomas (PPGLs), 24-h urine collections for metanephrines (uMNs) are cumbersome.

OBJECTIVE

To evaluate the diagnostic utility of ratios to creatinine of 'spot' uMNs.

METHODS

Concentrations of uMNs and plasma metanephrines (pMNs) were measured by HPLC-mass-spectrometry. We retrospectively compared correlations of 24-h-urine output and ratio to creatinine in historical specimens and prospectively assessed 24-h and contemporaneous spot urines and, where possible, pMNs. Using trimmed log-transformed values, we derived reference intervals based on age and sex for spot urines. We used multiples of upper limit of normal (ULNs) to compare areas under curves (AUCs) for receiver-operator characteristic curves of individual, and sum and product of, components.

RESULTS

In 3143 24-h-urine specimens on 2416 patients, the correlation coefficients between the ratios and outputs of metanephrine, normetanephrine and 3-methoxytyramine in 24-h urines were 0.983, 0.905 and 0.875, respectively. In 96 patients, the correlations between plasma concentrations, urine output and ratios in spot specimens were similar to those for raw output or ratios in 24-h specimens. Of the 160 patients with PPGLs, the CIs for AUCs for individual metabolites overlapped for all four types of measurement, as did those for the sum of the multiple ULNs although these were slightly higher (AUC for spot urine: 0.838 (0.529-1), plasma: 0.929 (0.874-0.984) and output: 0.858 (0.764-0.952)).

CONCLUSIONS

Ratios of fractionated metanephrines to creatinine in spot urine samples appear to have a similar diagnostic power to other measurements. The ease of spot urine collection may facilitate diagnosis and follow-up of PPGLs through improved patient compliance.

Activating Mutations of the G-protein Subunit α 11 Interdomain Interface Cause Autosomal Dominant Hypocalcemia Type 2

CONTEXT

Autosomal dominant hypocalcemia types 1 and 2 (ADH1 and ADH2) are caused by germline gain-of-function mutations of the calcium-sensing receptor (CaSR) and its signaling partner, the G-protein subunit α 11 (Gα 11), respectively. More than 70 different gain-of-function CaSR mutations, but only 6 different gain-of-function Gα 11 mutations are reported to date.

METHODS

We ascertained 2 additional ADH families and investigated them for CaSR and Gα 11 mutations. The effects of identified variants on CaSR signaling were evaluated by transiently transfecting wild-type (WT) and variant expression constructs into HEK293 cells stably expressing CaSR (HEK-CaSR), and measuring intracellular calcium (Ca2+i) and MAPK responses following stimulation with extracellular calcium (Ca2+e).

RESULTS

CaSR variants were not found, but 2 novel heterozygous germline Gα 11 variants, p.Gly66Ser and p.Arg149His, were identified. Homology modeling of these revealed that the Gly66 and Arg149 residues are located at the interface between the Gα 11 helical and GTPase domains, which is involved in guanine nucleotide binding, and this is the site of 3 other reported ADH2 mutations. The Ca2+i and MAPK responses of cells expressing the variant Ser66 or His149 Gα 11 proteins were similar to WT cells at low Ca2+e, but significantly increased in a dose-dependent manner following Ca2+e stimulation, thereby indicating that the p.Gly66Ser and p.Arg149His variants represent pathogenic gain-of-function Gα 11 mutations. Treatment of Ser66- and His149-Gα 11 expressing cells with the CaSR negative allosteric modulator NPS 2143 normalized Ca2+i and MAPK responses.

CONCLUSION

Two novel ADH2-causing mutations that highlight the Gα 11 interdomain interface as a hotspot for gain-of-function Gα 11 mutations have been identified.

Clinical Reliability of point-of-care tests to support community based acute ambulatory care

OBJECTIVE

To ensure clinicians can rely on point-of-care testing results, we assessed agreement between point-of-care tests for creatinine, urea, sodium, potassium, calcium, Hb, INR, CRP and subsequent corresponding laboratory tests.

PARTICIPANTS

Community-dwelling adults referred to a community-based acute ambulatory care unit.

INTERVENTIONS

The Abbott i-STATTM (Hb, clinical chemistry, INR) and the AfinionTM Analyser (CRP) and corresponding laboratory analyses.

OUTCOMES

Agreement (Bland-Altman) and bias (Passing-Bablok regression).

RESULTS

Among 462 adults we found an absolute mean difference between point-of-care and central laboratory analyses of 6.4g/L (95%LOA -7.9 to +20.6) for haemoglobin, -0.5mmol/L (95%LOA -4.5 to +3.5) for sodium, 0.2mmol/L (95%LOA -0.6 to +0.9) for potassium, 0.0mmol/L (95%LOA -0.3 to +0.3) for calcium, 9.0 μmol/L (95%LOA -18.5 to +36.4) for creatinine, 0.0mmol/L (95%LOA -2.7 to +2.6) for urea, -0.2 (95%LOA -2.4 to +2.0) for INR, -5.0 mg/L (95%LOA -24.4 to +14.4) for CRP.

CONCLUSIONS

There was acceptable agreement and bias for these analytes, except for haemoglobin and creatinine.

Recovery of the Hypothalamo-Pituitary-Adrenal Axis After Transsphenoidal Adenomectomy for Non-ACTH-Secreting Macroadenomas

CONTEXT

Secondary adrenal insufficiency is a potential complication of transsphenoidal adenomectomy (TSA). Most centers test recovery of the hypothalamo-pituitary-adrenal (HPA) axis after TSA, but, to our knowledge, there are no data predicting likelihood of recovery or the frequency of later recovery of HPA function.

OBJECTIVE

To assess timing and predictors of HPA axis recovery after TSA.

DESIGN

Single-center, retrospective analysis of consecutive pituitary surgeries performed between February 2015 and September 2018.

PATIENTS

Patients (N = 109) with short Synacthen test (SST) data before and at sequential time points after TSA.

MAIN OUTCOME MEASURES

Recovery of HPA axis function at 6 weeks, and 3, 6, and 9 to12 months after TSA.

RESULTS

Preoperative SST indicated adrenal insufficiency in 21.1% Among these patients, 34.8% recovered by 6 weeks after TSA. Among the 65.2% (n = 15) remaining, 13.3% and 20% recovered at 3 months and 9 to 12 months, respectively. Of the 29% of patients with adrenal insufficiency at the 6-week SST, 16%, 12%, and 6% subsequently recovered at 3, 6, and 9 to 12 months, respectively. Preoperative SST 30-minute cortisol, postoperative day 8 cortisol, and 6-week postoperative SST baseline cortisol levels above or below 430 nmol/L [15.5 μg/dL; AUC ROC, 0.86]; 160 nmol/L (5.8 μg/dL; AUC ROC, 0.75); and 180 nmol/L (6.5 μg/dL; AUC ROC, 0.88), were identified as cutoffs for predicting 6-week HPA recovery. No patients with all three cutoffs below the threshold recovered within 12 months after TSA, whereas 92% with all cutoffs above the threshold recovered HPA function within 6 weeks (OR, 12.200; 95% CI, 5.268 to 28.255).

CONCLUSION

HPA axis recovery can occur as late as 9 to 12 months after TSA, demonstrating the need for periodic reassessment of patients who initially have SST-determined adrenal insufficiency after TSA. Pre- and postoperative SST values can guide which patients are likely to recover function and potentially avoid unnecessary lifelong glucocorticoid replacement.

Experience of adopting faecal immunochemical testing to meet the NICE colorectal cancer referral criteria for low-risk symptomatic primary care patients in Oxfordshire, UK

OBJECTIVE

To compare the diagnostic performance of guaiac faecal occult blood (gFOB) testing with faecal immunochemical test (FIT) in a low-risk symptomatic primary care population to provide objective data on which to base local referral guidelines.

DESIGN

Stool samples from routine primary care practice sent for faecal occult blood testing were analysed by a standard gFOB method and the HM-JACKarc FIT between January and March 2016. Symptoms described on the test request were recorded. Patients were followed up over 21 months for evidence of serious gastrointestinal pathology including colorectal adenocarcinoma.

RESULTS

In 238 patients, the sensitivity and specificity for colorectal adenocarcinoma detection using gFOB were 85.7% and 65.8%, respectively, compared with 85.7% and 89.2% for FIT. The positive predictive value (PPV) for gFOB was 7.1% and negative predictive value (NPV) was 99.3%. Comparatively, the PPV for FIT was 19.4% and NPV 99.5%. The improved performance of FIT over gFOB was due to a lower false positive rate (10.8 vs 34.2, p≤0.01) with no increase in the false negatives rate. For any significant colorectal disease, the PPV for FIT increased to 35.5% with a reduction in NPV to 95.7%.

CONCLUSION

In this low-risk symptomatic patient group, the proportion of samples considered positive by FIT was considerably lower than gFOB with the same rate of colorectal adenocarcinoma detection. One in three of those with positive FIT had a significant colorectal disease. This supports National Institute of Health and Care Excellence recommendation that FIT can be reliably used as a triage test in primary care without overburdening endoscopy resources.

Prior Percutaneous Coronary Interventions May Be Associated With Increased Mortality After Coronary Bypass Grafting: A Meta-Analysis

There is conflicting evidence for adverse outcomes after coronary artery bypass surgery (CABG) with prior percutaneous intervention (PCI). A literature search was performed from 1998 to 2017 and articles with primary or secondary outcomes of survival, major adverse cardiovascular events (MACE), and myocardial infarction in CABG patients with prior PCI were included. Forest plots were generated from odds ratios for survival, MACE, and myocardial infarction for unmatched and propensity-matched data. Heterogeneity between studies was assessed for all outcomes using I². Funnel plots were generated for early survival, survival at 5 years, survival at >5 years, and MACE. Thirty-one studies were included over 18 years with 194,544 patients without PCI prior to CABG and 23,519 patients (12.09%) with prior PCI. Prior PCI did not adversely affect survival among the included studies (inverse rate ratio: 1.12, 95% confidence interval: 0.98-1.27, P = 0.110. MACE was significantly worse for those with prior PCI (odds ratio: 1.26, confidence interval: 1.02-1.55, P = 0.03). The relative risk of mortality associated with prior PCI has decreased significantly over the last 2 decades. Studies with higher percentage of prior PCI patients had higher relative mortalities. There was significant heterogeneity between studies for the treatment effects. PCI prior to CABG in recent times does not adversely affect survival despite adverse early and late MACE rates. However, high institutional rates of prior PCI may be associated with increasing mortality after CABG.

Among young Sri Lankan patients with diabetes, how do lipid profiles differ between those with and without metabolic syndrome?

AIMS

Metabolic syndrome (MetS) is a risk factor for cardiovascular disease (CVD). Apolipoproteins are emerging as powerful predictors of CVD. We aimed to study associations of metabolic syndrome and apoB, apoAI, apoB/AI ratio in young Sri Lankans with type 2 diabetes.

MATERIALS & METHODS

Blood samples were available from 690 patients with type 2 diabetes in Sri Lanka Young Diabetes Study, and were analysed for apoB, apoAI, total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), triglycerides (TG) and glycated haemoglobin (HbA_1c). Their associations with MetS as perNCEP/ATPIII criteria were studied.

RESULTS

MetS was present in 60.9% of subjects. Of those with MetS, 76.0% were women. Those with MetS had higher apoB (1.27 V s 1.19 mmol/L; p = 0.001), apoB/AI (0.80 V s 0.75; p = 0.001), non-HDL cholesterol (NHDLC) (4.15 V s 3.98 mmol/L; p = 0.002),and triglycerides (1.51 V s 1.31 mmol/L; p < 0.001) and lower apoAI (1.58 V s 1.60 mmol/L; p = 0.03) and HDLC (1.02 V s 1.16 mmol/L, p < 0.001). ApoB and apoB/AIlevels increased significantly as the number of MetS components increased. ApoB and apoB:AI ratio were independently associated with MetS and components.

CONCLUSION

MetS showed a high prevalence among young Sri Lankans with diabetes. Elevated apoB is commonly clustered with other risk indicators in MetS.

Measurement of urinary 5-HIAA: correlation between spot versus 24-h urine collection

BACKGROUND

The 24-h urinary output of 5-hydroxyindoleacetic acid (5-HIAA) is used to monitor disease progression and treatment responses of neuroendocrine neoplasms (NENs). Several conditions are required for 5-HIAA assay, involving urine collection/preservation and food/drug restrictions.

AIM

To evaluate the correlation between 5-HIAA concentration in a spot urine sample and the output in a 24-h urine collection, and whether spot urine specimens can replace 24-h collection.

METHODS

Patients with NENs or symptoms suggestive of NENs were asked to provide a separate spot urine at the end of the 24-h urine collection for 5-HIAA assessment. The upper reference limit for 24-h urinary 5-HIAA was 40 µmol/24 h. 5-HIAA measurements in spot urine samples were corrected for variation in urine flow rate by expressing results as a ratio to creatinine concentration.

RESULTS

We included 136 paired urinary samples for 5-HIAA assessment from 111 patients (100 NENs). The correlation between 5-HIAA values measured in 24-h and spot urines was r = +0.863 (P < 0.001) and r = +0.840 (P < 0.001) including only NEN patients. Using the 24-h urinary 5-HIAA as reference method, the AUC on ROC analysis for spot urinary 5-HIAA was 0.948 (95% CI, 0.914-0.983; P < 0.001), attaining a sensitivity of 83% and specificity of 95% using 5.3 mol/mmol as cut-off for the spot urine. The AUC among NEN patients alone was 0.945 (95% CI, 0.904-0.987; P < 0.001).

CONCLUSIONS

The ratio of 5-HIAA to creatinine in a spot urine could replace the measurement of 5-HIAA output in a 24-h urine collection, especially for follow-up of patients with known elevated 5-HIAA levels.

In primary care, is measuring free-thyroxine plus thyroid-stimulating hormone to detect hypopituitarism cost-effective? A cost utility analysis using Markov chain models

OBJECTIVE

We examined whether it is cost-effective to measure free thyroxine (FT4) in addition to thyrotropin (thyroid-stimulating hormone (TSH)) on all requests for thyroid function tests from primary care on adult patients.

BACKGROUND

Hypopituitarism occurs in about 4 people per 100 000 per year. Loss of thyrotropin (TSH) secretion may lead to secondary hypothyroidism with a low TSH and low FT4, and this pattern may help to diagnose hypopituitarism that might otherwise be missed.

DESIGN

Markov model simulation.

PRIMARY OUTCOME MEASURE

Incremental cost-effectiveness ratio (ICER), the ratio of cost in pounds to benefit in quality-adjusted life years of this strategy.

RESULTS

The ICER for this strategy was £71 437. Factors with a large influence on the ICER were the utilities of the treated hypopituitary state, the likelihood of going to the general practitioner (GP) and of the GP recognising a hypopituitary patient. The ICER would be below £20 000 at a cost to the user of an FT4 measurement of £0.61.

CONCLUSION

With FT4 measurements at their present cost to the user, routine inclusion of FT4 in a thyroid hormone profile is not cost-effective.

C-reactive protein and neutrophil count laboratory test requests from primary care: what is the demand and would substitution by point-of-care technology be viable?

AIMS : C-reactive protein (CRP) and neutrophil count (NC) are important diagnostic indicators of inflammation. Point-of-care (POC) technologies for these markers are available but rarely used in community settings in the UK. To inform the potential for POC tests, it is necessary to understand the demand for testing. We aimed to describe the frequency of CRP and NC test requests from primary care to central laboratory services, describe variability between practices and assess the relationship between the tests.

METHODS

We described the number of patients with either or both laboratory tests, and the volume of testing per individual and per practice, in a retrospective cohort of all adults in general practices in Oxfordshire, 2014-2016.

RESULTS

372 017 CRP and 776 581 NC tests in 160 883 and 275 093 patients, respectively, were requested from 69 practices. CRP was tested mainly in combination with NC, while the latter was more often tested alone. The median (IQR) of CRP and NC tests/person tested was 1 (1-2) and 2 (1-3), respectively. The median (IQR) tests/practice/week was 36 (22-52) and 72 (50-108), and per 1000 persons registered/practice/week was 4 (3-5) and 8 (7-9), respectively. The median (IQR) CRP and NC concentrations were 2.7 (0.9-7.9) mg/dL and 4.1 (3.1-5.5)×10⁹/L, respectively.

CONCLUSIONS

The high demand for CRP and NC testing in the community, and the range of results falling within the reportable range for current POC technologies highlight the opportunity for laboratory testing to be supplemented by POC testing in general practice.

Reduced kidney function at presentation in unselected acute emergency medical admissions: incidence, outcome and associated factors

We sought to assess the impact of renal impairment on acute medical admissions and to identify potential contributory factors to admissions involving renal impairment at presentation. In a prospective cohort study, 29.5% of all acute medical emergency admissions had an eGFR <60ml/min/1.73m2 at presentation. Of these, 19.9% had definite chronic kidney disease and 8.4% had definite acute kidney injury. Detailed analysis of a random subset of patients with an eGFR <60ml/min/1.73m2 at presentation demonstrated that the major reasons for admission included falls, dehydration and fluid overload. 46% were on diuretics and 53% were on an ACEI or ARB or both. Gastrointestinal disturbance and recent medication changes were common and diuretic use persisted even with diarrhoea or vomiting.

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.

Variation in diagnostic test requests and outcomes: a preliminary metric for OpenPathology.net

Efforts to reduce healthcare costs have led to the development of metrics to identify unwarranted variation in care. Previous work assessing diagnostic tests is limited, despite their substantial contribution to expenditure. We explored C-reactive Protein (CRP) and Erythrocyte Sedimentation Rate (ESR) tests ordered across Oxfordshire NHS General Practices, and the proportion of tests that yielded an abnormal result, and identified practices that had a proportion of abnormal CRP and ESR results 3 standard deviations below the mean. We estimated the adjusted average proportion of abnormal CRP and ESR tests that yielded abnormal results from each practice, after adjusting for differences in practice populations. These proportions were plotted against the total CRP and ESR requests per practice. We constructed funnel plots to identify practices 3 standard deviations below the mean proportion of abnormal CRP and ESR tests. We analysed 143,745 CRP and 30,758 ESR requests from 69 practices. Twelve (17%) and 7 (10%) practices were more than 3 standard deviations below the mean for CRP and ESR testing respectively. Two practices (3%) were below the 99.8% limit for both CRP and ESR ordering. Variation in the proportion of tests with an abnormal result shows promise for auditing variation in care.

Falsely elevated plasma metanephrine in patients taking midodrine

Plasma metanephrines have become the biochemical test of choice for suspected phaeochromocytomas and paragangliomas in many institutions. We encountered two separate cases of significantly elevated plasma metanephrines in patients taking midodrine, a sympathomimetic drug used in the treatment of severe postural hypotension, in the absence of a diagnosis of phaeochromocytomas and paragangliomas. Upon stopping midodrine treatment, plasma metanephrine concentrations returned to normal in both patients. To explore the hypothesis that midodrine or its metabolite desglymidodrine might interfere with the metanephrines assay, we tested the interaction of midodrine with metanephrine assays from two different centres. High-performance liquid chromatography tandem mass spectrometry on plasma samples and on methanolic extract of midodrine demonstrated co-elution of the metabolite desglymidodrine with metanephrine. We conclude that patients taking midodrine may have falsely elevated plasma metanephrine as a result of analytical interference, and clinicians need to be aware of this problem.

Routine genetic screening with a multi-gene panel in patients with pheochromocytomas

PURPOSE

Several new gene mutations have been reported in recent years to be associated with a risk of familial pheochromocytoma. However, it is unclear as to whether extensive genetic testing is required in all patients.

METHODS

The clinical data of consecutive patients operated for pheochromocytoma over a decade in a tertiary referral center were reviewed. Genetic screening was performed using a 10-gene panel: RET, VHL, SDHB, SDHD, SDHA, SDHC, SDHAF2, MAX, TMEM127 and FH.

RESULTS

A total of 166 patients were analyzed: 87 of them had genetic screening performed (39 M: 44.8%, 48 F: 55.2%, age range 6-81 years, mean 45±16.8 years). In total, 22/87 (25.3%) patients had germline mutations, while 65/87 (74.7%) patients presented with apparently sporadic tumors. Germline VHL mutations were identified in 11.7% of patients, RET in 6.8% (five MEN2A/MEN2 and one MEN2B/MEN3), SDHD in 2.3%, MAX in 2.3%, SDHB in 1.1%, and TMEM127 in 1.1% of patients. At diagnosis, 15.1% of patients with unilateral non-syndromic pheochromocytoma showed germline mutations. We identified 19.7% of mutations in patients with unilateral-non-recurrent pheochromocytomas within 5 years vs. 50% in the recurrent-bilateral-metastatic group (p = 0.01). Germline mutations were more frequently seen with bilateral pheochromocytomas (p = 0.001): 80% of patients with bilateral disease had germline mutations (4 VHL, 3 RET, 1 MAX).

CONCLUSIONS

The advent of rapid genetic screening using a gene-panel makes it feasible to screen large cohorts of patients and provides a valuable tool to contribute to the prediction of bilateral and malignant disease and to screen family members.