Jelic, Tomislav M., Raj, Ashok B., Jin, Bo, Kurczynski, Elizabeth M., Tolaymat, Naser, and Chang, Ho-Haung
Byline: Tomislav M. Jelic (1), Ashok B. Raj (2), Bo Jin (1), Elizabeth M. Kurczynski (3), Naser Tolaymat (4), Ho-Haung Chang (1) Keywords: Key words: CD5, chronic lymphocytic leukemia, hematogones, Shwachman-Diamond syndrome Abstract: We report increased numbers of hematogones in a 7-year-old girl with pancytopenia due to Shwachman-Diamond syndrome. Her hematogones expressed the T-cell marker CD5 as well as CD19, CD10, and CD20, and terminal deoxynucleotidyl transferase and HLA-DR. These findings suggest that hematogones are precursors of both CD5-positive B cells and CD5-negative B cells. Thus CD5-positive B cells in bone marrow may be derived from bone marrow stem cells, and not from the residual fetal B cells of yolk sac/liver origin. The finding of CD5 expression on hematogones also raises the possibility that neoplastic B cells of chronic lymphocytic leukemia, which characteristically co-express CD5 and CD19, may be derived from CD5-positive B-cell precursors in bone marrow and not from mature B cells in lymph nodes. Author Affiliation: (1) Department of Pathology, Charleston Area Medical Center, 3200 MacCorkle Avenue, Charleston, WV 25304, USA, US (2) Department of Pediatrics, Division of Pediatric Hematology/Oncology and Bone Marrow Transplant, University of Louisville, 571 S. Floyd Street, 445, Louisville, KY 40202, USA, US (3) Department of Pediatrics, Marshall University School of Medicine, 1600 Medical Court Drive, Huntington, WV 25701, USA, US (4) Department of Pediatrics, West Virginia University--Charleston, 830 Pennsylvania Avenue, Suite 104, Charleston, WV 25302, USA, US Article note: Received September 15, 2000 accepted April 25, 2001.