title: Chronic lymphocytic leukaemia: Clonal origin in a committed B-lymphocyte progenitor.
abstract: The glucose-6-phosphate dehydrogenase (G.-6-P.D.) types of isolated blood-cell populations and normal skin were determined in two patients with chronic lymphocytic leukaemia (C.L.L.) who were heterozygous at the G.-6-P.D. locus. Normal tissues from each patient manifested both A and B G.-6-P.D. types, but the C.L.L. B-lymphocyte preparation from one patient showed only a single enzyme type, and from the other patient it showed 95% activity of one G.-6-P.D. type. These observations confirm the supposition based on immunoglobulin-marker data that at the time of study C.L.L. has a clonal origin. In contrast to the B lymphocytes, granulocytes, erythrocytes, platelets, and T lymphocytes displayed both enzyme types in proportions similar to those found in skin. These findings indicate that C.L.L. involves committed B-lymphocyte progenitors. Thus, the disease stands in contrast to chronic myelocytic leukaemia and other myeloproliferative syndromes, all of which involve multipotent haemopoietic stem cells.
mesh_terms: D000368:Aged; D000818:Animals; D001402:B-Lymphocytes / Q000201:enzymology* / Q000276:immunology / Q000473:pathology; D002999:Clone Cells / Q000473:pathology; D005954:Glucosephosphate Dehydrogenase / Q000097:blood; D006412:Hematopoietic Stem Cells / Q000473:pathology*; D006579:Heterozygote; D006801:Humans; D007124:Immunoenzyme Techniques; D007527:Isoenzymes / Q000097:blood; D007945:Leukemia, Lymphoid / Q000097:blood / Q000209:etiology* / Q000235:genetics; D051379:Mice; D008875:Middle Aged; D011947:Receptors, Antigen, B-Cell / Q000096:biosynthesis; D012397:Rosette Formation; D012867:Skin / Q000201:enzymology
chemical_list: D007527:Isoenzymes; D011947:Receptors, Antigen, B-Cell; D005954:Glucosephosphate Dehydrogenase