Diagnostic Value and Prognostic Significance of Nucleated Red Blood Cells (NRBCs) in Selected Medical Conditions

Nucleated red blood cells as a prognostic marker for mortality in patients with SARS-CoV-2-induced ARDS: an observational study

BACKGROUND

The presence of nucleated red blood cells (NRBCs) in the peripheral blood of critically ill patients is associated with poor outcome. Evidence regarding the predictive value of NRBCs in patients with SARS-CoV-2-induced acute respiratory distress syndrome (ARDS) remains elusive. The aim of this study was to evaluate the predictive validity of NRBCs in these patients.

METHODS

Daily NRBC values of adult patients with SARS-CoV-2-induced ARDS were assessed and their predictive validity for mortality was statistically evaluated. A cut-off level based on the patient's maximum NRBC value during ICU stay was calculated and further specified according to Youden's method. Based on this cut-off value, further analyses such as logistic regression models and survival were performed.

RESULTS

413 critically ill patients with SARS-CoV-2-induced ARDS were analyzed. Patients who did not survive had significantly higher NRBC values during their ICU stay compared to patients who survived (1090/µl [310; 3883] vs. 140/µl [20; 500]; p < 0.0001). Patients with severe ARDS (n = 374) had significantly higher NRBC values during ICU stay compared to patients with moderate ARDS (n = 38) (490/µl [120; 1890] vs. 30/µl [10; 476]; p < 0.0001). A cut-off level of NRBC ≥ 500/µl was found to best stratify risk and was associated with a longer duration of ICU stay (12 [8; 18] vs. 18 [13; 27] days; p < 0.0001) and longer duration of mechanical ventilation (10 [6; 16] vs. 17 [12; 26] days; p < 0.0001). Logistic regression analysis with multivariate adjustment showed NRBCs ≥ 500/µl to be an independent risk factor of mortality (odds ratio (OR) 4.72; 95% confidence interval (CI) 2.95-7.62, p < 0.0001). Patients with NRBC values below the threshold of 500/µl had a significant survival advantage over those above the threshold (median survival 32 [95% CI 8.7-43.3] vs. 21 days [95% CI 18.2-23.8], log-rank test, p < 0.05). Patients who once reached the NRBC threshold of ≥ 500/µl during their ICU stay had a significantly increased long-term mortality (median survival 489 days, log-rank test, p = 0.0029, hazard ratio (HR) 3.2, 95% CI 1.2-8.5).

CONCLUSIONS

NRBCs predict mortality in critically ill patients with SARS-CoV-2-induced ARDS with high prognostic power. Further studies are required to confirm the clinical impact of NRBCs to eventually enhance decision making.

Pseudo-NRBC in the Mindray BC-6800Plus analyzer: A clue for diagnostic anticipation of fungemia. Experimental and preliminary clinical reports

INTRODUCTION

Candidemia can be a significant cause of death in immunosuppressed or debilitated patients particularly. Abnormalities of the instrumental cytograms of some hematological analyzers, such as Mindray BC-6800Plus, can be related to circulating Candida. We studied the possible diagnostic usefulness of this information.

METHODS

A fungal bloodstream infection has been simulated by adding aliquots of Candida albicans, Candida parapsilosis, and Candida glabrata to 75 leftovers and anonymized peripheral blood samples. Cytographic abnormalities like those of experimental samples were used to select patients with possible fungemia. The microscopic review of peripheral blood smears constituted the confirmatory method.

RESULTS

In all experimental samples, the various Candida types caused pseudo-NRBC and morphological abnormalities of WNB and DIFF cytograms. Circulating blastospores, free or engulfed by neutrophils, were the microscopic findings in the peripheral blood smears. In the clinical verification, 72 patients were recruited based on the presence of an evocative cluster in the WNB and DIFF cytograms. The microscopic review of 39 out of 72 samples was positive for NRBC. According to blood cultures, light microscopy revealed fungal forms of several Candida or non-Candida types in the remaining 33 samples. Nine of these cases were not yet known to suffer from bloodstream infection.

CONCLUSIONS

Although further confirmatory clinical studies are required for these diagnostic abilities, the BC 6800Plus cytographic abnormalities related to fungemia have proven helpful in rapidly monitoring persistent fungemia in already diagnosed patients. In unknown or undiagnosed cases, they could be the trigger point for the subsequent diagnostic-therapeutic pathway.

Nucleated red blood cells are a late biomarker in predicting intensive care unit mortality in patients with COVID-19 acute respiratory distress syndrome: an observational cohort study

Background

Nucleated red blood cells (nRBC) are precursor cells of the erythropoiesis that are absent from the peripheral blood under physiological conditions. Their presence is associated with adverse outcomes in critically ill patients. This study aimed to evaluate the predictive value of nRBC on mortality in intensive care unit (ICU) patients with COVID-19 acute respiratory distress syndrome (ARDS).

Material and methods

This retrospective, observational cohort study analyzed data on 206 ICU patients diagnosed with COVID-19 ARDS between March 2020 and March 2022. The primary endpoint was ICU mortality, and secondary endpoints included ICU and hospital stay lengths, ventilation hours, and the time courses of disease severity scores and clinical and laboratory parameters.

Results

Among the included patients, 68.9% tested positive for nRBC at least once during their ICU stay. A maximum nRBC of 105 µl-1 had the highest accuracy in predicting ICU mortality (area under the curve of the receiver operating characteristic [AUCROC] 0.780, p < 0.001, sensitivity 69.0%, specificity 75.5%). Mortality was significantly higher among patients with nRBC >105 µl-1 than ≤105 µl-1 (86.5% vs. 51.3%, p = 0.008). Compared to patients negative for nRBC in their peripheral blood, those positive for nRBC required longer mechanical ventilation (127 [44 - 289] h vs. 517 [255 - 950] h, p < 0.001), ICU stays (12 [8 - 19] vs. 27 [13 - 51] d, p < 0.001), and hospital stays (19 [12 - 29] d vs. 31 [16 - 58] d, p < 0.001). Peak Sepsis-related Organ Failure Assessment (SOFA), Simplified Acute Physiology Score, PaO2/FiO2, interleukin-6, and procalcitonin values were reached before the peak nRBC level. However, the predictive performance of the SOFA (AUCROC 0.842, p < 0.001) was considerably improved when a maximum SOFA score >8 and nRBC >105 µl-1 were combined.

Discussion

nRBC predict ICU mortality and indicate disease severity among patients with COVID-19 ARDS, and they should be considered a clinical alarm signal for a worse outcome. nRBC are a late predictor of ICU mortality compared to other established clinical scoring systems and laboratory parameters but improve the prediction accuracy when combined with the SOFA score.

Prognostic Significance of Nucleated RBCs in Predicting Mortality Among ST-Elevation Myocardial Infarction Patients Admitted to the ICU

Background The nucleated red blood cells (NRBCs) are a readily available hematological parameter with potential for risk stratification for mortality. Therefore, our objective was to assess the predictive significance of NRBCs for ICU mortality among ST-elevation myocardial infarction (STEMI) patients admitted to an ICU. Additionally, we aimed to compare the predictive capacity of NRBCs with that of the acute physiology and chronic health evaluation (APACHE) II score and the sequential organ failure assessment (SOFA) score. Methodology This descriptive cross-sectional study was conducted in the ICU of the National Institute of Cardiovascular Diseases (NICVD) in Karachi, Pakistan, from the 1st of February to the 30th of June, 2023. We included adult patients (≥18 years) diagnosed with STEMI who were subsequently admitted to the ICU. NRBCs were assessed in all patients over up to five days at 24-hour intervals, and the highest NRBC levels were used for the final analysis. Furthermore, the APACHE II score and the SOFA score were also documented. Patients were monitored throughout their ICU stay, and any adverse events or complications, such as re-intubation, bleeding necessitating transfusion, requirement for renal replacement therapy, arrhythmias, re-infarction, and mortality, were recorded. Results This study included 151 patients, of whom 97 (64.2%) were male, with an average age of 61.1 ± 10.7 years. Patients with positive NRBCs had higher mean SOFA scores (7.4 ± 2.9 vs. 5.4 ± 2.6; p < 0.001) and APACHE II scores (14.6 ± 6.3 vs. 12.6 ± 5.5; p = 0.037) compared to those with negative NRBCs. The culprit vessel showed greater mean stenosis (%) in patients with positive NRBCs (98.8 ± 3.0% vs. 96.8 ± 5.7%; p = 0.004). Post-procedure thrombolysis in myocardial infarction (TIMI) flow grade III was lower in patients with positive NRBCs (77.8% vs. 91.8% for positive vs. negative NRBCs, respectively). Moreover, patients with positive NRBCs experienced significantly higher mortality rates (63% vs. 8.2%; p < 0.001), a higher occurrence of arrhythmias (35.2% vs. 19.6%; p = 0.034), and an increased requirement for vasopressors/inotropic support (96.3% vs. 71.1%; p < 0.001) compared to those with negative NRBCs. NRBCs demonstrated superior discriminatory ability compared to the SOFA and APACHE II scores, with an area under the curve of 0.818 (95% CI: 0.738-0.899) for NRBCs, 0.774 (95% CI: 0.692-0.857) for SOFA, and 0.707 (95% CI: 0.613-0.801) for APACHE II. Positive NRBCs exhibited a sensitivity of 81.0% and a specificity of 81.7% in predicting ICU mortality. Conclusion In conclusion, positive NRBCs emerge as a robust and reliable prognostic indicator, strongly associated with an elevated risk of ICU mortality in STEMI patients. Moreover, the predictive power of positive NRBCs surpasses that of both SOFA and APACHE II scoring systems.