title: The role of interleukin-6 in a patient with polyclonal hairy B-cell lymphoproliferative disorder: a case report.
abstract: An 80-year-old female patient showed persistent lymphocytosis morphologically resembling the Japanese variant of hairy cell leukemia (HCL). However, flow cytometric analysis determined that these lymphocytes were of polyclonal B-cell origin, showing CD5-, CD10(-), CD11c(+), CD19(+), CD20(+), CD23(-), CD103(-), FMC7(-), HLA-DR(+) and surface membrane immunoglobulin (smIg) G(+) phenotype. The female patient also showed polyclonal hypergammaglobulinemia with bone marrow plasmacytosis. The patient was diagnosed as having hairy B-cell lymphoproliferative disorder (HBLD). Serum interleukin-6 (IL-6) level was elevated at the time of diagnosis in this patient, but IL-6 receptor (CD126) was not expressed on the hairy B-cells. Intracellular IL-6 was not detected in these cells either, suggesting that IL-6 did not play an important role in the B-lymphocytosis present in our patient with HBLD.
authors.affiliation: Department of Medicine, Nantan General Hospital, Nantan, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Okamoto
authors.forename: Tohru
authors.initials: T
authors.lastname: Inaba
authors.forename: Naohisa
authors.initials: N
authors.lastname: Fujita
mesh_terms: D000369:Aged, 80 and over; D001402:B-Lymphocytes / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D015850:Interleukin-6 / Q000097:blood* / Q000502:physiology*; D007564:Japan; D007943:Leukemia, Hairy Cell / Q000175:diagnosis* / Q000209:etiology; D008218:Lymphocytosis; D008232:Lymphoproliferative Disorders / Q000175:diagnosis* / Q000209:etiology; D019947:Receptors, Interleukin-6 / Q000172:deficiency
chemical_list: D015850:Interleukin-6; D019947:Receptors, Interleukin-6