title: Persistent polyclonal B-cell lymphocytosis--an important differential diagnosis of B-cell chronic lymphocytic leukemia.
abstract: Over the last 17 years, 83 cases of polyclonal B-cell lymphocytosis (PPBL) have been published. This rare hematological disorder of unknown etiology is characterized by morphologically atypical lymphocytes, polyclonal immunoglobulin M production in association with smoking, female gender, and HLA-DR7 phenotype. We studied another male patient with PPBL. In contrast to normal B-cells, PPBL cells showed no response to interleukin-4 with regard to CD23 and human leukocyte antigen-DR expression. F2mu antibodies failed to co-stimulate interleukin-4-mediated CD23 expression. Crosslinking membrane immunoglobulin M receptors by F2mu resulted in elevated human leukocyte antigen-DR expression but did not induce in vitro proliferation of PPBL cells. This indicates a different activation and differentiation status than normal B-cells.
authors.affiliation: Medizinische Poliklinik der Universität, Würzburg, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Reimer
authors.forename: F
authors.initials: F
authors.lastname: Weissinger
authors.forename: H P
authors.initials: HP
authors.lastname: Tony
authors.forename: K H
authors.initials: KH
authors.lastname: Koniczek
authors.forename: M
authors.initials: M
authors.lastname: Wilhelm
mesh_terms: D000328:Adult; D001402:B-Lymphocytes / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000175:diagnosis* / Q000473:pathology; D008218:Lymphocytosis / Q000175:diagnosis* / Q000473:pathology; D008297:Male