CD7 is expressed on a subset of normal CD34‐positive myeloid precursors

• Published in: European journal of haematology 2018-09, Vol.101 (3), p.318-325
• Main Authors: Kriegsmann, Katharina, Löffler, Harald, Eckstein, Volker, Schulz, Renate, Kräker, Sandra, Braun, Ute, Luft, Thomas, Hegenbart, Ute, Schönland, Stefan, Dreger, Peter, Krämer, Alwin, Ho, Anthony D., Müller‐Tidow, Carsten, Hundemer, Michael
• Format: Article
• Language: English
• Subjects: Antigens, CD34 - metabolism; Antigens, CD7 - genetics; Antigens, CD7 - metabolism; Biomarkers; Bone marrow; Bone Marrow Cells - metabolism; Bone Marrow Cells - pathology; Bone marrow transplantation; CD13 antigen; CD34 antigen; CD7; CD7 antigen; Chimerism; Flow cytometry; Gene Expression; Humans; Immunophenotyping; Leukemia; Leukemia, Myeloid - diagnosis; Leukemia, Myeloid - genetics; Leukemia, Myeloid - metabolism; leukemia‐associated immunophenotype (LAIP); Lymphatic leukemia; Minimal residual disease; minimal residual disease (MRD); myeloid neoplasia; Myeloid Progenitor Cells - metabolism; Myeloid Progenitor Cells - pathology; Neoplasia; Neoplasm, Residual - diagnosis; Neoplasm, Residual - genetics; Neoplasm, Residual - metabolism; Osteoprogenitor cells; Peripheral blood; Phenotypes; Remission; Stem cell transplantation; Tumors
• ISSN: 0902-4441; 1600-0609
• DOI: 10.1111/ejh.13100

Objective To improve monitoring of myeloid neoplasms by flow cytometry‐based minimal residual disease (MRD) analysis, we analyzed the significance of leukemia‐associated immunophenotype (LAIP) markers in 44 patients. Methods In a pilot study cohort, peripheral blood or bone marrow samples from 13 patients with myeloid neoplasms and one case of B lymphoblastic leukemia in complete hematologic remission after allogeneic bone marrow or stem cell transplantation were subjected to selection for leukemia‐specific phenotypes by fluorescence‐activated cell sorting using individual marker combinations, followed by PCR‐based chimerism analysis. Results The feasibility of this method could be demonstrated, with selection being successful in 12 cases, including two cases where mixed chimerism was found exclusively in sorted cells. Interestingly, four specimens displayed full donor chimerism in cells expressing the presumably aberrant combination CD34+/CD7+. Further analyses, including assessment of an independent cohort of 25 patients not affected by neoplastic bone marrow infiltration, revealed that normal myeloid precursors usually include a population coexpressing CD34, CD13, CD33, and CD7. Conclusion We conclude that the combination CD34+/CD7+ might not be suitable as an LAIP for MRD diagnostics and that a subset of normal myeloid precursors in the bone marrow expresses CD7.