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

Abstract

Nucleated red blood cells (NRBCs) are premature erythrocyte precursors that reside in the bone marrow of humans of all ages as an element of erythropoiesis. They rarely present in healthy adults’ circulatory systems but can be found circulating in fetuses and neonates. An NRBC count is a cost-effective laboratory test that is currently rarely used in everyday clinical practice; it is mostly used in the diagnosis of hematological diseases/disorders relating to erythropoiesis, anemia, or hemolysis. However, according to several studies, it may be used as a biomarker in the diagnosis and clinical outcome prognosis of preterm infants or severely ill adult patients. This would allow for a quick diagnosis of life-threatening conditions and the prediction of a possible change in a patient’s condition, especially in relation to patients in the intensive care unit. In this review, we sought to summarize the possible use of NRBCs as a prognostic marker in various disease entities. Research into the evaluation of the NRBCs in the pediatric population most often concerns neonatal hypoxia, the occurrence and consequences of asphyxia, and overall neonatal mortality. Among adults, NRBCs can be used to predict changes in clinical condition and mortality in critically ill patients, including those with sepsis, trauma, ARDS, acute pancreatitis, or severe cardiovascular disease.

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

“…Nevertheless, the clinical benefit of improving risk stratification through nRBC measurement might be impaired given our data showing that nRBC peaks were considerably delayed compared to the peaks in the examined disease severity scores and clinical parameters, such as P a O 2 /F i O 2 , IL-6, and PCT. Therefore, it must be questioned whether nRBC positivity might be the final but emerging result of severe hypoxemia and inflammation that only becomes apparent after other parameters have already indicated worsening critical illness ( 29 ). However, recent evidence has emerged that nRBC themselves might be immune cell mediators of the antiviral host response and can even provide immunosuppressive properties compromising the response against systemic infections ( 30 , 31 ).…”

“…Furthermore, while nRBC measurements are widely available today and predictivity in distinct critically ill patient populations is well-known, no clinical recommendation exists for nRBC measurement in critically ill or ICU patients. While the distinct mechanisms leading to nRBC release remain unknown, it is negatively correlated with arterial oxygen saturation and, consequently, with hypoxemia, higher levels of erythropoietin and proinflammatory cytokines, such as IL-3 and IL-6 ( 16 , 29 , 32 ). Our study confirms these observations, showing lower P a O 2 /F i O 2 and higher PCT values in patients with an nRBC count >105 µl -1 .…”

Correlation of nucleated red blood cell counts by Sysmex XN-1000 with conventional microscopy

“…Nucleated red blood cells are an important prognostic indicator for many haematological and non-haematological diseases. They are especially important in patients with thalassemia, as the presence of nRBCs in their peripheral blood indicates ineffective erythropoiesis [13]. Furthermore, in critically ill patients nRBCs are now being used as early diagnostic and prognostic marker.…”

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

“…At a cut-off of 26 points, the scoring system exhibited a sensitivity of 89.1%, specificity of 67.2%, negative predictive value of 97.9%, and positive predictive value of 26.8% [ 26 ]. Over the past five decades, scientific advancements and the introduction of automated peripheral blood cell counting have transformed complete blood cell counts into vital clinical tools for identifying hematopoietic responses to existing injury [ 26 , 27 ]. Consequently, these variables not only mirror ischemia and its hemodynamic repercussions but also encapsulate inflammatory processes, infectious or not-during hospitalization, that might contribute to higher AMI patient mortality rates.…”