Flow Cytometric Enumeration of Peripheral Blood CD34+ Cells Predicts Bone Marrow Pathology in Patients with Less Than 1% Blasts by Manual Count

Abstract

Tomislav M Jelic,1 Oscar C Estalilla,1 Jeffrey A Vos,2 Gary Harvey,1 Caitlin J Stricker,1 Ayodele O Adelanwa,2 Ahmed A Khalid,3 Milton J Plata1 1Department of Pathology and Laboratory Medicine, Charleston Area Medical Center, Charleston, WV, USA; 2Department of Pathology, Anatomy and Laboratory Medicine, West Virginia University School of Medicine, Morgantown, WV, USA; 3Cancer Center, Charleston Area Medical Center, Charleston, WV, USACorrespondence: Tomislav M Jelic, Charleston Area Medical Center, Department of Pathology and Laboratory Medicine, 3200 MacCorkle Avenue, Charleston, WV, 25304, USA, Tel [phone], Email [email protected] and Aims: Significance of absolute number of CD34+ cells in the peripheral blood of patients with less than 1% myeloblasts by manual differential count is unknown and our aim is to study its relevance in clinical practice.Methods: We studied 138 peripheral bloods flow cytometric analyses in patients with less than 1% myeloblasts by manual differential, when CD34+ events were present in the gate that encompassed lymphocytes, monocytes, stem cells, and blasts.Results: The average absolute number of CD34+cells in the peripheral blood was 11 CD34+cells/μL ranging from less than 1 cell/μL to 147 cells/μL. The average absolute number of CD34+ cells in patients with an abnormal expansive process involving bone marrow (metastases, myelodysplasia, granulomas, marrow infections) or if bone marrow biopsy not performed, presumed expansive marrow process was 25 cells/μL, and in patients without an expansive marrow process (or presumed negative) was 4 cells/μL (P< 0.00007). Cutoff 12 CD34+ cells/μL had 93% positive predictive value for bone marrow involvement by an expansive process and 78% negative predictive value.Conclusion: Flow cytometric testing of the peripheral blood is extremely sensitive method for enumerating CD34+ cells and can detect fewer than one CD34+ cell/μL. The absolute number of CD34+ cells in the peripheral blood is a useful parameter in determining marrow involvement by an expansive process and may provide guidance with respect to the necessity for bone marrow biopsy.Keywords: flow cytometry, CD34 positive cells, peripheral blood, myeloblasts, bone marrow biopsy

Keywords

• flow cytometry
• cd34 positive cells
• peripheral blood
• myeloblasts
• bone marrow biopsy.