Serum creatinine to absolute lymphocyte count ratio effectively risk stratifies patients who require intensive care in hospitalized patients with coronavirus disease 2019

Abstract

Patients with preexisting kidney disease or acute kidney injury had poorer outcomes in coronavirus disease 2019 illness. Lymphopenia was associated with more severe illness. Risk stratification with simple laboratory tests may help appropriate site patients in a cost-effective manner and ease the burden on healthcare systems. We examined a ratio of serum creatinine level to absolute lymphocyte count at presentation (creatinine-lymphocyte ratio, CLR) in predicting outcomes in hospitalized patients with COVID-19. We analyzed 553 consecutive polymerase chain reaction-positive SARS-COV-2 hospitalized patients. Patients with end-stage kidney disease were excluded. Serum creatinine and full blood count (FBC) examination were obtained within the first day of admission. We examined the utility of CLR in predicting adverse clinical outcomes (requiring intensive care, mechanical ventilation, acute kidney injury requiring renal replacement therapy or death). An optimized cutoff of CLR > 77 was derived for predicting adverse outcomes (72.2% sensitivity, and 83.9% specificity). Ninety-seven patients (17.5%) fell within this cut off. These patients were older and more likely to have chronic medical conditions. A higher proportion of these patients had adverse outcomes (13.4% vs 1.1%, P < .001). On receiver operating curve analyses, CLR predicted patients who had adverse outcomes well (area under curve [AUC] = 0.82, 95%CI 0.72-0.92), which was comparable to other laboratory tests like serum ferritin, C-reactive protein and lactate dehydrogenase. Elevated CLR on admission, which may be determined by relatively simple laboratory tests, was able to reasonably discriminate patients who had experienced adverse outcomes during their hospital stay. This may be a simple and cost-effective means of risk stratification and triage.Abbreviations: AKI = acute kidney injury, AUC = area under curve, CLR = creatinine-to-lymphocyte ratio, COVID-19 = coronavirus disease 2019, FBC = full blood count, ROC = receiver operating characteristic, SARS-CoV-2 = severe acute respiratory distress syndrome coronavirus 2.

Predictors of disease severity in SARS‐CoV‐2 omicron variant XBB sublineages and variants of interest

“…Among patients hospitalized with Omicron XBB SARS‐CoV‐2, we observed that advanced age and the presence of chronic kidney disease predicted adverse outcomes. Previously reported markers such as radiographic evidence of pneumonia, elevated C‐reactive protein, and serum creatinine levels at presentation also correlated with adverse outcomes 6,7 . In our hospitalized cohort, there were no observable differences in outcomes with any specific Omicron XBB sublineage, and with prevalence similar to trends from national surveillance data, where XBB.1.16 (23%) and XBB.2.3 (29.5%) were also the commonest (unpublished data from Ministry of Health, Singapore).…”

“…Previously reported markers such as radiographic evidence of pneumonia, elevated Creactive protein, and serum creatinine levels at presentation also correlated with adverse outcomes. 6,7 In our hospitalized cohort, there were no observable differences in outcomes with any specific Omicron XBB sublineage, and with prevalence similar to trends from national surveillance data, where XBB.…”

Inflammatory phenotypes may be more important than age and comorbidities in predicting clinical outcomes in hospitalised patients with COVID-19

“…Our findings showed that SARS-CoV-2 has different effects on individual patients, and we found these can be predicted more accurately by their inflammatory status than by age, comorbidities, and viral load, which were consistently associated with severe disease in the COVID-19 literature [25] . That the hyperinflammatory phenotype is a stronger predictor of progression to more severe disease may be explained by the association of inflammation with dysfunction in other organ systems beyond the respiratory system, such as the heart, lungs, and kidneys [26 , 27] .…”

Response to comments on: Silent hypoxia: pulse oximetry and its relation to COVID-19 in Singapore

“…We had previously examined the varied clinical manifestations of acute COVID-19 and shown that multiple organ systems, beyond the lungs, can be affected. In a moderately sized, retrospective cohort of hospitalised patients with mild COVID-19, consisting of primarily young and immunocompetent migrant workers in Singapore, we had observed that the infection can present with multi-system involvement, including cardiac manifestations,[ 4 ] kidney injury,[ 5 ] altered haematological profile[ 6 ] and elevated liver enzymes. [ 7 ] While some of these organ-specific complications may be related to the uncontrolled host inflammatory response to the viral infection, a majority of the patients we had examined were largely afebrile, asymptomatic and with relatively mild disease.…”