Objectives Vitamin D has a role in the innate immunity against pathogens and is also involved in mechanisms for reducing inflammation. VD deficiency (VDD) may increase COVID-19 infection susceptibility, however research is limited on the association between VDD and COVID-19 symptom prevalence and duration. The study aimed to determine whether VDD is a risk factor for the presence and extended duration of COVID-19 symptoms. Methods Data was analyzed from NHS healthcare workers who isolated due to COVID-19 symptoms as a part of the COVID-19 convalescent immunity study between 12th to 22nd May 2020. Participants self-reported the presence and duration of viral symptoms. Anti-SARS-CoV-2 antibodies and vitamin D (25(OH)D3) serum levels were measured on day of recruitment. VDD was defined as 25(OH)D3 levels of < 30 nmol/l. Results Of the 392 participants, 15.6% (n = 61) had VDD. VDD participants had more symptoms overall (p = 0.0030), including body aches (p = 0.0453), and extended duration of body aches (p = 0.0075) and fatigue (p = 0.0127). Binary logistic regression found that both VDD (OR 3.069, 95% CI 1.538-6.124; p = 0.001) and age (OR 1.026, 95% CI 1.003-1.049; p = 0.025) were independently associated with extended durations of body aches. VDD (OR 2.089, 95% CI 1.087-4.011; p = 0.027), age (OR 1.036, 95% CI 1.016-1.057; p < 0.001) and seroconversion (OR 1.917, 95% CI 1.203-3.056; p = 0.006), were independently associated with extended durations of fatigue. Conclusion VDD is a significant independent risk factor for extended durations of body aches and fatigue in healthcare workers who isolated for COVID-19 viral symptoms. Vitamin D supplementation may reduce symptom duration and is thus an area for future research.

Background: PTH assays are not standardized; therefore, method-specific PTH reference intervals are required for interpretation of results. PTH increases with age in adults but age-related reference intervals for the Abbott intact PTH (iPTH) assay are not available. Methods: Deidentified serum PTH results from September 2015 to November 2022 were retrieved from the laboratory information system of a laboratory serving a cosmopolitan population in central-west England for individuals aged 18 years and older if the estimated glomerular filtration rate was >= 60 mL/min, serum 25-hydroxyvitamin D was >50 nmol/L, and serum albumin-adjusted calcium and serum phosphate were within reference intervals. Age-specific reference intervals for Abbott iPTH were derived by an indirect method using the refineR algorithm. Results: PTH increased with age and correlated with age when controlled for 25-hydroxyvitamin D, estimated glomerular filtration rate, and adjusted calcium (r = 0.093, P < .001). The iPTH age-specific reference intervals for 4 age partitions of 18 to 45 years, 46 to 60 years, 61 to 80 years, and 81 to 95 years were 1.6 to 8.6 pmol/L, 1.8 to 9.5 pmol/L, 2.0 to 11.3 pmol/L, and 2.3 to 12.3 pmol/L, respectively. PTH was higher in women compared with men (P < .001). Sex-specific age-related reference intervals could not be derived because of the limited sample size. Conclusion: Age-specific Abbott iPTH reference intervals were derived. Application of age-specific reference intervals will impact the diagnosis and management of normocalcemic hyperparathyroidism, based on current definitions, and secondary hyperparathyroidism. Additional studies are required to clarify the effect of sex and ethnicity on PTH.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Background PTH assays are not standardized; therefore, method-specific PTH reference intervals are required for interpretation of results. PTH increases with age in adults but age-related reference intervals for the Abbott intact PTH (iPTH) assay are not available. Methods Deidentified serum PTH results from September 2015 to November 2022 were retrieved from the laboratory information system of a laboratory serving a cosmopolitan population in central-west England for individuals aged 18 years and older if the estimated glomerular filtration rate was ≥60 mL/min, serum 25-hydroxyvitamin D was >50 nmol/L, and serum albumin-adjusted calcium and serum phosphate were within reference intervals. Age-specific reference intervals for Abbott iPTH were derived by an indirect method using the refineR algorithm. Results PTH increased with age and correlated with age when controlled for 25-hydroxyvitamin D, estimated glomerular filtration rate, and adjusted calcium (r = 0.093, P < .001). The iPTH age-specific reference intervals for 4 age partitions of 18 to 45 years, 46 to 60 years, 61 to 80 years, and 81 to 95 years were 1.6 to 8.6 pmol/L, 1.8 to 9.5 pmol/L, 2.0 to 11.3 pmol/L, and 2.3 to 12.3 pmol/L, respectively. PTH was higher in women compared with men (P < .001). Sex-specific age-related reference intervals could not be derived because of the limited sample size. Conclusion Age-specific Abbott iPTH reference intervals were derived. Application of age-specific reference intervals will impact the diagnosis and management of normocalcemic hyperparathyroidism, based on current definitions, and secondary hyperparathyroidism. Additional studies are required to clarify the effect of sex and ethnicity on PTH.

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.

Glucocorticoids prescribed to limit inflammation, have significant adverse effects. As 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) regenerates active glucocorticoid, we investigated whether 11β-HSD1 inhibition with AZD4017 could mitigate adverse glucocorticoid effects without compromising their anti-inflammatory actions. We conducted a proof-of-concept, randomized, double-blind, placebo-controlled study at Research Unit, Churchill Hospital, Oxford, UK (NCT03111810). 32 healthy male volunteers were randomized to AZD4017 or placebo, alongside prednisolone treatment. Although the primary endpoint of the study (change in glucose disposal during a two-step hyperinsulinemic, normoglycemic clamp) wasn't met, hepatic insulin sensitivity worsened in the placebo-treated but not in the AZD4017-treated group. Protective effects of AZD4017 on markers of lipid metabolism and bone turnover were observed. Night-time blood pressure was higher in the placebo-treated but not in the AZD4017-treated group. Urinary (5aTHF+THF)/THE ratio was lower in the AZD4017-treated but remained the same in the placebo-treated group. Most anti-inflammatory actions of prednisolone persisted with AZD4017 co-treatment. Four adverse events were reported with AZD4017 and no serious adverse events. Here we show that co-administration of AZD4017 with prednisolone in men is a potential strategy to limit adverse glucocorticoid effects.

Background and aims: On November 8th, 2022, the United States Food and Drug Administration (FDA) issued a statement alerting healthcare professionals to the increasing prevalence of xylazine in illicit drug overdoses in the country. Xylazine is a veterinary medicine with sedative, analgesic and muscle relaxant properties that is used as a heroin/fentanyl adulterant on the illicit drug market in North America. Here we report the first drugrelated death associated with xylazine in the United Kingdom. Methods: The National Programme on Substance Abuse Deaths (NPSAD) receives reports on drug-related deaths from coroners In England, Wales and Northern Ireland on a voluntary basis. The NPSAD was searched for cases with xylazine detections in cases received by December 31, 2022. Results: One drug-related death associated with xylazine use was reported to NPSAD by December 31, 2022. The deceased was a 43-year-old male who was found dead at home with drug paraphernalia located at the property in May 2022. The post-mortem examination identified recent puncture wounds to the groin. Coronial documentation reports that the deceased had a history of illicit drug use. A number of drugs were detected by post-mortem toxicology and xylazine was implicated in death alongside heroin, fentanyl and cocaine. Conclusions: To the best of our knowledge, this is the first death associated with xylazine use reported in the UK, and even Europe, and indicates the entry of xylazine into the UK drug supply. This report highlights the importance of monitoring changes in illicit drug markets and the emergence of new drugs.

Background There is increasing evidence that vitamin D (VD) deficiency may increase individuals’ risk of COVID-19 infection and susceptibility. We aimed to determine the relationship between VD deficiency and sufficiency and COVID-19 seropositivity within healthcare workers.Methods The study included an observational cohort of healthcare workers who isolated due to COVID-19 symptoms from 12 May to 22 May 2020, from the University Hospitals Birmingham National Health Service Foundation Trust. Data collected included SARS-CoV-2 seroconversion status, serum 25(OH)D3 levels, age, body mass index (BMI), sex, ethnicity, job role and comorbidities. Participants were grouped into four VD categories: (1) Severe VD deficiency (VD<30 nmol/L); (2) VD deficiency (30 nmol/L ≤VD<50 nmol/L); (3) VD insufficiency (50 nmol/L ≤VD<75 nmol/L); (4) VD sufficiency (VD≥75 nmol/L).Results When VD levels were compared against COVID-19 seropositivity rate, a U-shaped curve was identified. This trend repeated when participants were split into subgroups of age, sex, ethnicity, BMI and comorbidity status. Significant difference was identified in the COVID-19 seropositivity rate between VD groups in the total population and between groups of men and women; black, Asian and minority ethnic (BAME) group; BMI<30 (kg/m2); 0 and +1 comorbidities; the majority of which were differences when the severely VD deficient category were compared with the other groups. A larger proportion of those within the BAME group (vs white ethnicity) were severely VD deficient (p<0.00001). A larger proportion of the 0 comorbidity subgroup were VD deficient in comparison to the 1+ comorbidity subgroup (p=0.046).Conclusions Our study has shown a U-shaped relationship for COVID-19 seropositivity in UK healthcare workers. Further investigation is required to determine whether high VD levels can have a detrimental effect on susceptibility to COVID-19 infection. Future randomised clinical trials of VD supplementation could potentially identify ‘optimal’ VD levels, allowing for targeted therapeutic treatment for those at risk.

Objectives All guidelines recommend LC-MS/MS as the analytical method of choice for the quantification of immunosuppressants in whole blood. Until now, the lack of harmonization of methods and the complexity of the analytical technique have prevented its widespread use in clinical laboratories. This can be seen in international proficiency schemes, where more than half of the participants used immunoassays. With the Cascadion SM Clinical analyzer (Thermo Fisher Scientific, Oy, Vantaa, FI) a fully automated LC-MS/MS system has been introduced, which enables the use of LC-MS/MS without being an expert in mass spectrometry. Methods To verify the interlaboratory comparison of the immunosuppressant assay on this type of instrument, three centers across Europe compared 1097 routine whole blood samples, each site sharing its own samples with the other two. In other experiments, the effects of freezing and thawing of whole blood samples was studied, and the use of secondary cups instead of primary tubes was assessed. Results In the Bland-Altman plot, the comparison of the results of tacrolimus in fresh and frozen samples had an average bias of only 0.36%. The respective data for the comparison between the primary and secondary tubes had an average bias of 1.14%. The correlation coefficients for patient samples with cyclosporine A (n=411), everolimus (n=139), sirolimus (n=114) and tacrolimus (n=433) were 0.993, 0.993, 0.993 and 0.990, respectively. Conclusions The outcome of this study demonstrates a new level of result harmonization for LC-MS/MS based immunosuppressant analysis with a commercially available fully automated platform for routine clinical application.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

The coronavirus disease 2019 (COVID-19) pandemic is a global health emergency, resulting in over 50 million infections and over 1.2 million deaths as of mid-November 2020 [1]. Healthcare workers are at a high risk of COVID-19 with large numbers of deaths reported around Europe and the UK, particularly among staff in the Black, Asian and minority ethnic (BAME) demographic group [2]. COVID-19 has disproportionately affected BAME individuals even after accounting for age, sex, social deprivation and comorbidity [3]. NHS staff with vitamin D deficiency were more likely to have developed COVID-19, with staff from BAME ethnicity being the most vitamin D deficient We thank the staff of University Hospitals Birmingham NHS Foundation Trust who kindly volunteered for this study. We would also like to thank the research staff of the Birmingham Wellcome NIHR Clinical Research Facility who undertook the staff facing assessments. We would like to thank colleagues at the Clinical Immunology Service for overseeing recruitment and sample processing. We also thank our colleagues Prof Adrian Martineau from Queen Mary University of London, Prof Elizabeth Sapey, Dr Dhruv Parekh, both from University of Birmingham and Prof Jon Rhodes from University of Liverpool, who have given helpful feedback on the study results and manuscript.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Summary Background It is clear that in UK healthcare workers, COVID-19 infections and deaths were more likely to be in staff who were of BAME origin. This has led to much speculation about the role of vitamin D in healthcare worker COVID-19 infections. We aimed to determine the prevalence of vitamin D deficiency in NHS staff who have isolated with symptoms suggestive of COVID-19 and relate this to vitamin D status. Methods We recruited NHS healthcare workers between 12 th to 22 nd May 2020 as part of the COVID-19 convalescent immunity study (COCO). We measured anti-SARS-Cov-2 antibodies using a combined IgG, IgA and IgM ELISA (The Binding Site). Vitamin D status was determined by measurement of serum 25(OH)D 3 using the AB SCIEX Triple Quad 4500 mass spectrometry system. Findings Of the 392 NHS healthcare workers, 214 (55%) had seroconverted for COVID-19. A total of 61 (15.6%) members of staff were vitamin D deficient (<30 nmol/l) with significantly more staff from BAME backgrounds or in a junior doctor role being deficient. Vitamin D levels were lower in those who were younger, had a higher BMI (>30 kg/m 2 ), and were male. Multivariate analysis revealed that BAME and COVID-19 seroconversion were independent predictors of vitamin D deficiency. Staff who were vitamin D deficient were more likely to self-report symptoms of body aches and pains but importantly not the respiratory symptoms of cough and breathlessness. Vitamin D levels were lower in those COVID-19 positive staff who reported fever, but this did not reach statistical significance. Within the whole cohort there was an increase in seroconversion in staff with vitamin D deficiency compared to those without vitamin D deficiency (n=44/61, 72% vs n=170/331, 51%; p=0·003); this was particularly marked in the proportion of BAME males who were vitamin D deficient compared to non-vitamin D deficient BAME males (n=17/18, 94% vs n=12/23, 52%; p=0·005). Multivariate analysis revealed that vitamin D deficiency was an independent risk factor for seroconversion (OR 2·6, 95%CI 1·41–4·80; p=0·002). Interpretation In those healthcare workers who have isolated due to symptoms of COVID-19, those of BAME ethnicity are at the highest risk of vitamin D deficiency. Vitamin D deficiency is a risk factor for COVID-19 seroconversion for NHS healthcare workers especially in BAME male staff. Funding This study was funded internally by the University of Birmingham and University Hospitals Birmingham NHS Foundation Trust and supported by the National Institute for Health Research (NIHR)/Wellcome Trust Birmingham Clinical Research Facility. AAF and DRT are funded by the Medical Research Council (MR/S002782/1). The Binding Site (Edgbaston, UK) have provided reagents and plates for the SARS-CoV-2 ELISA free of charge. Research in context Evidence before this study The ongoing COVID-19 pandemic has raised several questions, one of which is whether individuals with vitamin D deficiency were at a greater risk of being infected or having a severe outcome if infected. Among UK healthcare workers, and indeed the general population, individuals of BAME ethnicity are disproportionately affected by COVID-19. It is well established that individuals of BAME ethnicity have a higher prevalence of vitamin D deficiency, but it is unknown if vitamin D deficiency among UK NHS workers was connected to the risk of COVID-19 infection. Our search of the literature revealed no previous studies have established the prevalence of vitamin D deficiency within a UK NHS trust. Unsurprisingly, there is also no evidence to suggest if vitamin D deficiency was connected to the risk of infection among UK healthcare workers. Added value of this study In this study of healthcare workers who had isolated for COVID-19 symptoms towards the end of UK surge within a large UK NHS trust, 15.6% were vitamin D deficient. Our data also reveal that healthcare workers of BAME ethnicity and those who had seroconverted for COVID-19 were more likely to be vitamin D deficient. Multivariate analysis also show that vitamin D deficiency was the only predictor of COVID-19 seroconversion. Vitamin D deficient healthcare workers that are BAME and male had a 94% seroconversion for COVID-19 compared to non-deficient BAME males suggesting they are more at risk of COVID-19 if vitamin D deficient. Implications of all the available evidence There is an increased risk of COVID-19 infection in healthcare workers with vitamin D deficiency. Our data adds to the emerging evidence from studies in the UK and across the globe that individuals with severe COVID-19 are more vitamin D deficient than those with mild disease. Finally, ours and the available evidence demonstrate vitamin D supplementation in individuals at risk of vitamin D deficiency or shown to be deficient may help alleviate the impact of COVID-19.

BACKGROUND: Nonadherence to oral prednisolone is an important driver of poor control in severe asthma, and its detection is warranted to guide management. RESEARCH QUESTION: The goal of this study was to evaluate the utility of liquid chromatography and tandem mass spectrometry (LC-MS/MS) in determining the adherence status to oral prednisolone in severe asthma. STUDY DESIGN AND METHODS: Timeline serum levels of prednisolone, cortisol, and metabolites were measured by using a validated LC-MS/MS assay following observed intake of prednisolone in patients receiving maintenance oral prednisolone. Patterns of adherence and nonadherence were determined from analysis of peak blood levels. The performance of a spot test for adherence (detectable prednisolone and suppressed cortisol) was assessed in a second cohort of patients receiving maintenance prednisolone and a control group. RESULTS: In the prednisolone absorption test, 27 patients (mean age, 38.6 years; age range, 17-63 years; 83% female) were included. We identified adherence in 13 (48%), nonadherence in 13 (48%), and malabsorption in one (3.7%). The median [interquartile range] peak serum assays of the adherent group compared with the nonadherent group were: cortisol, 36 [39.5] vs 295 [153] nmol/L; and prednisolone, 1,810 [590] vs 1,730 [727] nmol/L. The spot test cohort included 111 patients (67 on maintenance prednisolone and 44 control subjects); the mean age was 42.4 years, and 79% were female. Nonadherence was detected in 40.3% of patients; comparison of the adherent vs nonadherent groups revealed median [interquartile range] levels for cortisol of 27 [48] nmol/L vs 211 [130] nmol/L and for prednisolone of 259 [622] nmol/L vs < 20 nmol/L, respectively. Adherent patients had higher mean BMI (38.4 +/- 8.7 vs 32 +/- 7.5 kg/m2; P = .03), lower median blood eosinophils (0.09 [0.31] vs 0.51 [0.53] x 109/L; P < .001), and a trend toward reduced mean annual severe exacerbations (3.0 +/- 2.6 vs 4.3 +/- 2.4; P = .3) than nonadherent patients. INTERPRETATION: Nonadherence to oral prednisolone is common in severe asthma and can be reliably detected in the clinic by using the LC-MS/MS assay.