Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios: associations with mortality in a haemodialysis cohort.

Background: Lymphocyte ratios reflect inflammation and have been associated with adverse outcomes in a range of diseases. We sought to determine any association between neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) and mortality in a haemodialysis cohort, including a coronavirus disease 2019 (COVID-19) infection subpopulation. Methods: A retrospective analysis was performed of adults commencing hospital haemodialysis in the West of Scotland during 2010-21. NLR and PLR were calculated from routine samples around haemodialysis initiation. Kaplan-Meier and Cox proportional hazards analyses were used to assess mortality associations. Results: In 1720 haemodialysis patients over a median of 21.9 (interquartile range 9.1-42.9) months, there were 840 all-cause deaths. NLR but not PLR was associated with all-cause mortality after multivariable adjustment [adjusted hazard ratio (aHR) for in participants with baseline NLR in quartile 4 (NLR ≥8.23) versus quartile 1 (NLR <3.12) 1.63, 95% confidence interval (CI) 1.32-2.00]. The association was stronger for cardiovascular death (NLR quartile 4 versus 1 aHR 3.06, 95% CI 1.53-6.09) than for non-cardiovascular death (NLR quartile 4 versus 1 aHR 1.85, 95% CI 1.34-2.56). In the COVID-19 subpopulation, both NLR and PLR at haemodialysis initiation were associated with risk of COVID-19-related death after adjustment for age and sex (NLR: aHR 4.69, 95% CI 1.48-14.92 and PLR: aHR 3.40, 95% CI 1.02-11.36; for highest vs lowest quartiles). Conclusions: NLR is strongly associated with mortality in haemodialysis patients while the association between PLR and adverse outcomes is weaker. NLR is an inexpensive, readily available biomarker with potential utility in risk stratification of haemodialysis patients.

Acute kidney injury in patients hospitalized with COVID-19 from the ISARIC WHO CCP-UK Study: a prospective, multicentre cohort study.

BACKGROUND: Acute kidney injury (AKI) is common in coronavirus disease 2019 (COVID-19). This study investigated adults hospitalized with COVID-19 and hypothesized that risk factors for AKI would include comorbidities and non-White race. METHODS: A prospective multicentre cohort study was performed using patients admitted to 254 UK hospitals with COVID-19 between 17 January 2020 and 5 December 2020. RESULTS: Of 85 687 patients, 2198 (2.6%) received acute kidney replacement therapy (KRT). Of 41 294 patients with biochemistry data, 13 000 (31.5%) had biochemical AKI: 8562 stage 1 (65.9%), 2609 stage 2 (20.1%) and 1829 stage 3 (14.1%). The main risk factors for KRT were chronic kidney disease (CKD) [adjusted odds ratio (aOR) 3.41: 95% confidence interval 3.06-3.81], male sex (aOR 2.43: 2.18-2.71) and Black race (aOR 2.17: 1.79-2.63). The main risk factors for biochemical AKI were admission respiratory rate >30 breaths per minute (aOR 1.68: 1.56-1.81), CKD (aOR 1.66: 1.57-1.76) and Black race (aOR 1.44: 1.28-1.61). There was a gradated rise in the risk of 28-day mortality by increasing severity of AKI: stage 1 aOR 1.58 (1.49-1.67), stage 2 aOR 2.41 (2.20-2.64), stage 3 aOR 3.50 (3.14-3.91) and KRT aOR 3.06 (2.75-3.39). AKI rates peaked in April 2020 and the subsequent fall in rates could not be explained by the use of dexamethasone or remdesivir. CONCLUSIONS: AKI is common in adults hospitalized with COVID-19 and it is associated with a heightened risk of mortality. Although the rates of AKI have fallen from the early months of the pandemic, high-risk patients should have their kidney function and fluid status monitored closely.

Genetic epidemiology of SARS-CoV-2 transmission in renal dialysis units - A high risk community-hospital interface.

OBJECTIVES: Patients requiring haemodialysis are at increased risk of serious illness with SARS-CoV-2 infection. To improve the understanding of transmission risks in six Scottish renal dialysis units, we utilised the rapid whole-genome sequencing data generated by the COG-UK consortium. METHODS: We combined geographical, temporal and genomic sequence data from the community and hospital to estimate the probability of infection originating from within the dialysis unit, the hospital or the community using Bayesian statistical modelling and compared these results to the details of epidemiological investigations. RESULTS: Of 671 patients, 60 (8.9%) became infected with SARS-CoV-2, of whom 16 (27%) died. Within-unit and community transmission were both evident and an instance of transmission from the wider hospital setting was also demonstrated. CONCLUSIONS: Near-real-time SARS-CoV-2 sequencing data can facilitate tailored infection prevention and control measures, which can be targeted at reducing risk in these settings.

Prolonged SARS-CoV-2 viral shedding in patients with chronic kidney disease.

Recent World Health Organization guidance has aimed to provide pragmatic guidance acknowledging the role of sequential nasopharyngeal swabs taken >24 hours apart for SARS-CoV-2 in high-risk populations. Patients with chronic kidney disease (CKD) are known to have an altered immune milieu which may be associated with a delay in viral clearance. Here, a cross-sectional observational study of 138 patients admitted with SARS-CoV-2 infection at two large regional hospitals in Scotland, UK examined the median time to two consecutive negative nasopharyngeal swabs for SARS-CoV-2 in an inpatient population. The median time from admission to the first of two consecutive negative nasopharyngeal swabs was 18 days (range = 1-44) in patients with CKD, compared with 11 days (range: 1-71) in patients without CKD (P = .0007). Multivariable linear regression analysis using explanatory variables of age, sex, SARS-CoV-2 disease severity, key comorbidities and renal function showed that declining estimated glomerular filtration rate was independently associated with prolonged time to viral clearance. Our data suggest that patients with CKD who are admitted to hospital with SARS-CoV-2 take longer to achieve sequential negative nasopharyngeal swab reverse transcription-polymerase chain reaction results than those without CKD. This has implications for renal service provision, discharge planning and hospital capacity as well as a direct impact on patients due to extended hospital stay, anxiety and stigmatisation.