From the Guidelines
The presence of nucleated red blood cells in peripheral blood smear is indicative of bone marrow infiltration and warrants further staging, including unilateral bone marrow aspirates and biopsies, in patients with small cell lung cancer (SCLC) 1. In the context of SCLC, the detection of nucleated red blood cells on peripheral blood smear is a significant finding that may suggest bone marrow involvement. According to the NCCN clinical practice guidelines in oncology 1, bone marrow involvement as the only site of extensive-stage disease occurs in fewer than 5% of patients.
- The guidelines recommend that unilateral bone marrow aspirates and biopsies may be indicated in select patients with nucleated red blood cells on peripheral blood smear, neutropenia, or thrombocytopenia suggestive of bone marrow infiltration and with no other evidence of metastatic disease 1.
- The use of PET/CT scans can also increase staging accuracy in patients with SCLC, particularly in detecting distant metastases 1.
- However, in patients with suspected bone marrow infiltration, bone marrow aspirates and biopsies are essential for confirming the diagnosis and guiding treatment decisions 1.
- It is crucial to note that the presence of nucleated red blood cells in peripheral blood smear is not exclusive to SCLC and can be associated with other conditions, emphasizing the need for comprehensive staging and diagnostic workup 1.
From the Research
Nucleated Red Blood Cells
- Nucleated red blood cells (NRBCs) are not normally found in the peripheral blood of healthy individuals 2
- The presence of NRBCs in adults indicates a high demand for red blood cell production and can be associated with various pathogenic conditions, such as anemia, myelofibrosis, and malignancies 2
- NRBCs can be used as a prognostic marker in critically ill patients, including those with sepsis, trauma, and severe cardiovascular disease 3
Clinical Significance of NRBCs
- The incidence of NRBCs in ICU-admitted patients was 62.5%, with a mortality rate of 30% in NRBC-positive patients 2
- A cutoff of NRBCs of 2.50 showed a high risk of mortality with a sensitivity of 91% 2
- The presence of NRBCs may predict mortality in critically ill ICU-admitted patients and can be regarded as a marker of severity 2
Reference Intervals for NRBCs
- The original reference interval for NRBCs was 0.00 to 0.01 × 106/μL, but a recent study suggested updating the upper limit to 0.10 × 106/μL 4
- This update could decrease patient anxiety and unnecessary follow-up care, without causing patient harm 4
Nucleated Red Blood Cells in Bone Marrow
- Nucleated red blood cells are present in normal bone marrow and can be counted manually on bone marrow smears 5
- The number of NRBCs in bone marrow increases with the age of the donor and can affect the total nucleated cell count (TNCC) 5
Digital Assessment of Peripheral Blood and Bone Marrow
- Digital analysis of peripheral blood and bone marrow aspirate smears can provide significant benefits, including improved accuracy and throughput 6
- Recent research has focused on developing advanced machine learning models for digital peripheral blood assessment and automated bone marrow aspirate smear analysis 6