From the Research
A normal CD34 count in bone marrow typically ranges from 1-5% of total nucleated cells, while a low CD34 count is generally considered to be below 1%. CD34 is a cell surface marker found on hematopoietic stem and progenitor cells, which are responsible for producing all blood cell types. The CD34 count is particularly important in evaluating bone marrow function and is commonly assessed before stem cell transplantation procedures.
Key Points to Consider
- Low CD34 counts may indicate bone marrow failure, myelodysplastic syndromes, or other conditions affecting hematopoiesis.
- The count can be influenced by various factors including age, underlying diseases, previous chemotherapy, and radiation exposure.
- When evaluating CD34 counts, it's essential to consider the patient's clinical context, as values may need to be interpreted differently based on individual circumstances.
- For stem cell collection purposes, a minimum threshold of 2 million CD34+ cells/kg recipient body weight is typically targeted to ensure successful engraftment, as supported by a systematic review and meta-analysis 1.
Clinical Implications
- The CD34 count is a critical parameter in assessing bone marrow function and guiding clinical decisions, such as the need for stem cell transplantation or other interventions.
- Accurate interpretation of CD34 counts requires consideration of the patient's overall clinical context, including underlying diseases, previous treatments, and other factors that may influence hematopoiesis.
- Further research is needed to fully understand the significance of CD34 counts in different clinical contexts and to develop evidence-based guidelines for their interpretation and application, as highlighted by studies on CD34+ cells in normal human bone marrow 2 and the use of CD34-selected stem cell boost for poor graft function after allogeneic hematopoietic stem cell transplantation 1.