title: Two cases of myelodysplastic syndrome with extramedullary polyclonal plasma cell proliferation and autoantibody production: possible role of soluble Fas antigen for production of excessive self-reactive B cells.
abstract: Two cases of myelodysplastic syndrome (MDS) with extramedullary polyclonal plasma cell proliferation and autoantibody production are reported. These cases, which showed leukemic change of refractory anemia with excess of blast (RAEB), developed lymph node swelling and muscle abscess; both were infiltrated mainly with plasma cells, without preceding infection. The proliferation of plasma cells was polyclonal and was proven by negative rearrangement of immunoglobulin heavy chain gene or polyclonal staining of immunoglobulin light chains. These patients showed polyclonal gammopathy and autoantibody production such as positive antinuclear factor and direct antiglobulin test. As was observed in one of the present cases, and as we reported previously, the elevated level of soluble Fas antigen in MDS patients, and its inhibition of apoptotic signaling may be responsible for the excessive accumulation of self-reactive B cells, resulting in these clinical manifestations.
authors.affiliation: Department of Medicine, Yamaguchi Prefecture Central Hospital, Hofu.
authors.forename: K
authors.initials: K
authors.lastname: Katsuki
authors.forename: K
authors.initials: K
authors.lastname: Shinohara
authors.forename: N
authors.initials: N
authors.lastname: Kameda
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.forename: K
authors.initials: K
authors.lastname: Takeda
authors.forename: T
authors.initials: T
authors.lastname: Kamei
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000754:Anemia, Refractory, with Excess of Blasts / Q000150:complications / Q000276:immunology / Q000473:pathology*; D000974:Antibodies, Antinuclear / Q000096:biosynthesis / Q000276:immunology; D017209:Apoptosis / Q000276:immunology; D001323:Autoantibodies / Q000096:biosynthesis* / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D014408:Biomarkers, Tumor / Q000097:blood; D001706:Biopsy; D001853:Bone Marrow / Q000473:pathology; D002455:Cell Division / Q000276:immunology; D017809:Fatal Outcome; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009190:Myelodysplastic Syndromes / Q000150:complications / Q000276:immunology / Q000473:pathology*; D010950:Plasma Cells / Q000276:immunology / Q000473:pathology*; D019014:fas Receptor / Q000276:immunology*
chemical_list: D000974:Antibodies, Antinuclear; D001323:Autoantibodies; D014408:Biomarkers, Tumor; D019014:fas Receptor