Relationship between platelet/lymphocyte ratio and prognosis of patients with septic acute kidney injury: A pilot study

The association between the triglyceride‒glucose index and short-term mortality in ICU patients with sepsis-associated acute kidney injury

BACKGROUND

The triglyceride-glucose (TyG) index has emerged as a novel marker for insulin resistance and is commonly observed in patients suffering from sepsis-associated acute kidney injury (SA-AKI). This study explored the correlation between the TyG index and short-term all-cause mortality among SA-AKI patients.

METHODS

We performed a retrospective analysis of ICU patients with SA-AKI using data from the MIMIC-IV database. The primary outcomes were 28-day and 90-day all-cause mortality. Multivariate Cox proportional hazards regression, restricted cubic spline (RCS) models, and Kaplan‒Meier (K‒M) survival analyses were used to examine the associations between the TyG index and mortality. Subgroup and sensitivity analyses were conducted to ensure the robustness of the findings.

RESULTS

The study included 4971 SA-AKI patients, with 2873 males (57.8%), an average age of 65.4 years (± 15.8), and an average TyG index of 9.10 (± 0.70). RCS analysis revealed a U-shaped relationship between the TyG index and mortality. When the TyG index was below 9.04, the risk of mortality at both 28 days and 90 days was reduced (adjusted HRs of 0.695, 95% CI: 0.542-0.890 and 0.691, 95% CI: 0.557-0.858, respectively). In contrast, values above 9.04 were associated with increased mortality, though the relationship was not statistically significant (adjusted HRs of 1.026, 95% CI: 0.855-1.231 and 1.012, 95% CI: 0.863-1.188, respectively). K‒M analysis revealed higher mortality rates for patients with either high (T3) or low (T1) TyG indices than for those with moderate (T2) TyG indices. Sensitivity analyses confirmed these associations even after excluding patients with diabetes, cerebrovascular diseases, or ICU stays of less than 2 days.

CONCLUSION

The TyG index is significantly and nonlinearly associated with short-term all-cause mortality in SA-AKI patients; however, establishing a causal relationship between the two requires validation through larger prospective studies.

Association between lactate dehydrogenase to albumin ratio and acute kidney injury in patients with sepsis: a retrospective cohort study

BACKGROUND

Serum lactate dehydrogenase to albumin ratio (LAR) is associated with poor outcomes in malignancy and pneumonia. However, there are few studies suggesting that LAR is associated with the occurrence of acute kidney injury (AKI) in patients with sepsis, which was investigated in this study.

METHODS

We conducted a retrospective cohort study based on the Medical Information Mart for Intensive Care (MIMIC)-IV database. The primary outcome was the occurrence of AKI within 2 days and 7 days. Multivariable logistic regression models were used to calculate odds ratios to validate the association between LAR and AKI, in-hospital mortality, RRT use, and recovery of renal function, respectively.

RESULTS

A total of 4010 participants were included in this study. The median age of the participants was 63.5 years and the median LAR was 10.5. After adjusting for confounding variables, patients in the highest LAR quartile had a higher risk of AKI than those in the lowest LAR quartile within 2 days and 7 days, with odds ratios of 1.37 (95% confidence interval [CI]: 1.23-1.52) and 1.95 (95% CI: 1.72-2.22), respectively. The adjusted odds of AKI within 2 and 7 days were 1.16 (95% CI: 1.12-1.20) and 1.29 (95% CI: 1.24-1.35) for each 1 unit increase in LAR(log2), respectively.

CONCLUSION

This study demonstrated that elevated LAR was associated with poor prognosis in patients with sepsis. The risk of AKI and in-hospital mortality increased, the need for RRT increased, and the chance of recovery of renal function decreased with the increase of LAR.

Predictive Risk Score for Acute Kidney Injury in Hematopoietic Stem Cell Transplant

Hematopoietic stem cell transplant (HSCT) is an important treatment option for hematologic malignancies. Acute kidney injury (AKI) is a common complication in HSCTs and is related to worse outcomes. We aimed to create a predictive risk score for AKI in HSCT considering variables available at the time of the transplant. We performed a retrospective cohort study. AKI was defined by the KDIGO classification using creatinine and urinary output criteria. We used survival analysis with competing events. Continuous variables were dichotomized according to the Liu index. A multivariable analysis was performed with a backward stepwise regression. Harrel's C-Statistic was used to evaluate the performance of the model. Points were attributed considering the nearest integer of two times each covariate's hazard ratio. The Liu index was used to establish the optimal cut-off. We included 422 patients undergoing autologous (61.1%) or allogeneic (38.9%) HSCTs for multiple myeloma (33.9%), lymphoma (27.3%), and leukemia (38.8%). AKI cumulative incidence was 59.1%. Variables eligible for the final score were: hematopoietic cell transplant comorbidity index ≥2 (HR: 1.47, 95% CI: 1.08-2.006; p = 0.013), chronic kidney disease (HR: 2.10, 95% CI: 1.31-3.36; p = 0.002), lymphoma or leukemia (HR: 1.69, 95% CI: 1.26-2.25; p < 0.001) and platelet-to-lymphocyte ratio > 171.9 (HR: 1.43, 95% CI: 1.10-1.86; p = 0.008). This is the first predictive risk score for AKI in patients undergoing HSCTs and the first study where the platelet-to-lymphocyte ratio is independently associated with AKI.

Platelet Function in Acute Kidney Injury: A Systematic Review and a Cohort Study

Acute kidney injury (AKI) patients have increased bleeding risk, which could be partially due to acquired platelet dysfunction. We conducted a systematic review and a cohort study to investigate platelet function and count in AKI and their association with AKI-related bleeding and mortality. Through a systematic literature search in PubMed and Embase, we identified 9 studies reporting platelet function and 56 studies reporting platelet count or platelet indices in AKI patients. Overall, platelet aggregation was reduced in AKI patients in nonintensive care unit (ICU) settings but not in ICU settings, except that reduced aggregation was associated with renal replacement therapy. Thrombocytopenia in AKI was frequent and often predictive of mortality. In our cohort study, we prospectively included 54 adult ICU patients who developed AKI within 24 hours of ICU admission and 33 non-AKI ICU controls. Platelet function was measured with light transmission aggregometry and flow cytometry. AKI patients bled more frequently than non-AKI patients (p = 0.04), and bleeding was associated with increased 30-day mortality in AKI (p = 0.02). However, platelet function was not different between AKI and non-AKI patients (aggregation: all p > 0.52; flow cytometry: all p > 0.07) and platelet function was not associated with bleeding in AKI. In conclusion, a reduced platelet count is frequent in AKI, but the literature on platelet function in AKI is sparse. In a cohort study, we demonstrated that patients with AKI within 24 hours of ICU admission exhibited increased bleeding tendency but this was not associated with reduced platelet function.

Prediction Models for One-Year Survival of Adult Patients with Acute Kidney Injury: A Longitudinal Study Based on the Data from the Medical Information Mart for Intensive Care III Database

Acute kidney injury (AKI) is a common complication of acute illnesses with unfavorable outcomes. This cohort study aimed at constructing prediction models for one-year survival in adult AKI patients based on prognostic nutritional index (PNI), platelet-to-lymphocyte ratio (PLR), neutrophil percentage-to-albumin ratio (NPAR), or neutrophil-to-lymphocyte ratio (NLR), respectively. In total, 6050 patients from Medical Information Mart for Intensive Care III (MIMIC-III) were involved. The least absolute shrinkage and selection operator (LASSO) regression was utilized to screen possible covariates. The samples were randomly divided into the training set and the testing set at a ratio of 7.5 : 2.5, and the prediction models were constructed in the training set by random forest. The prediction values of the models were measured via sensitivity, specificity, negative prediction value (NPV), positive prediction value (PPV), area under the curve (AUC), and accuracy. We found that NLR (OR = 1.261, 95% CI: 1.145–1.388), PLR (OR = 1.295, 95% CI: 1.152–1.445), and NPAR (OR = 1.476, 95% CI: 1.261–1.726) were associated with an increased risk, while PNI (OR = 0.035, 95% CI: 0.020–0.059) was associated with a decreased risk of one-year mortality in AKI patients. The AUC was 0.964 (95% CI: 0.959–0.969) in the training set based on PNI, age, gender, length of stay (LOS) in hospital, platelets (PLT), ethnicity, LOS in ICU, systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate, glucose, AKI stage, atrial fibrillation (AF), vasopressor, renal replacement therapy (RRT), and mechanical ventilation. The testing set was applied as the internal validation of the model with an AUC of 0.778 (95% CI: 0.754–0.801). In conclusion, PNI accompanied by age, gender, ethnicity, SBP, DBP, heart rate, PLT, glucose, AF, RRT, mechanical ventilation, vasopressor, AKI stage, LOS in ICU, and LOS in hospital exhibited a good predictive value for one-year mortality of AKI patients.

Prognostic Value of Platelet to Lymphocyte Ratio in Sepsis: A Systematic Review and Meta-analysis

The goal of this study was to conduct a systematic review of the literature on the relationship between peripheral blood platelet to lymphocyte ratio (PLR) and mortality in sepsis and to integrate the findings in a meta-analysis. An electronic search of three main databases was performed: PubMed, Embase, and Scopus on 19 December 2021. Finally, 16 studies comprising 2403 septic patients, including 1249 survivors and 1154 nonsurvivors, were included in this meta-analysis. We found that PLR levels were significantly higher in nonsurvivors than in survivors (random effect model: SMD = 0.72, 95% CI; 0.35–1.10, p < 0.001). However, significant heterogeneity was observed across the studies (I² = 94.1%, p < 0.01). So, we used random effect model in our meta-analysis. In the subgroup analysis, according to mortality time, patients deceased during one month after sepsis had elevated levels of PLR compared to survivors (SMD = 1.03, 95% CI = 0.15-1.92, p = 0.22). However, in-hospital mortality was not associated with PLR level (SMD = 0.41, 95% CI = −0.18-0.99, p = 0.175). Our findings support PLR to be a promising biomarker that can be readily integrated into clinical settings to aid in the prediction and prevention of sepsis mortality.

Hematological Ratios Are Associated with Acute Kidney Injury and Mortality in Patients That Present with Suspected Infection at the Emergency Department

The early recognition of acute kidney injury (AKI) is essential to improve outcomes and prevent complications such as chronic kidney disease, the need for renal-replacement therapy, and an increased length of hospital stay. Increasing evidence shows that inflammation plays an important role in the pathophysiology of AKI and mortality. Several inflammatory hematological ratios can be used to measure systemic inflammation. Therefore, the association between these ratios and outcomes (AKI and mortality) in patients suspected of having an infection at the emergency department was investigated. Data from the SPACE cohort were used. Cox regression was performed to investigate the association between seven hematological ratios and outcomes. A total of 1889 patients were included, of which 160 (8.5%) patients developed AKI and 102 (5.4%) died in <30 days. The Cox proportional-hazards model revealed that the neutrophil-to-lymphocyte ratio (NLR), segmented-neutrophil-to-monocyte ratio (SMR), and neutrophil-lymphocyte-platelet ratio (NLPR) are independently associated with AKI <30 days after emergency-department presentation. Additionally, the NLR, SMR and NLPR were associated with 30-day all-cause mortality. These findings are an important step forward for the early recognition of AKI. The use of these markers might enable emergency-department physicians to recognize and treat AKI in an early phase to potentially prevent complications.

Role of platelet-to-lymphocyte count ratio (PLR), as a prognostic indicator in COVID-19: A systematic review and meta-analysis

Prognostic predictors are of paramount interest for prompt intervention and optimal utilization of the healthcare system in the ongoing context of the COVID-19 pandemic. The platelet-to-lymphocyte count ratio (PLR), has emerged as a potential tool for risk stratification of critically ill patients with sepsis. The current systematic review explores the utility of PLR as a prognostic predictor of COVID-19 patients. We screened the electronic databases until May 15, 2021 after enrolling in PROSPERO (CRD42021220269). Studies evaluating the association between PLR on admission and outcomes in terms of mortality and severity among COVID-19 patients were included. We retrieved 32 studies, with a total of 2768 and 3262 COVID-19 patients for mortality and disease severity outcomes. Deceased and critically ill patients had higher PLR levels on admission in comparison to survivors and non-severe patients (mean differences [MD] = 66.10; 95% confidence interval [CI]: 47.75-84.44; p < 0.00001 and MD = 86.74; 95% CI: 67.7-105.7; p < 0.00001, respectively). A higher level of PLR on admission in COVID-19 patients is associated with increased morbidity and mortality. However, the evidence is of low quality and further studies regarding the cut-off value of PLR are the need of the hour.