title: Large granular lymphocytic proliferation-associated cyclic thrombocytopenia.
abstract: Cyclic thrombocytopenia is a rare condition characterized by regular fluctuations in the platelet count, resulting in bleeding at the time of platelet count nadir. We evaluated a male patient whose platelet count cycled between <10x10(9)/L and a maximum of >1300x10(9)/L over a median of every 42 days (range, 28-57 days). Antiplatelet antibodies were present at highest titer just prior to platelet nadirs. A pathologic expansion of CD3+CD57+ large granular lymphocytes (LGLs) along with a clonal rearrangement of the T-cell receptor (TCR) gamma gene in circulating T cells was detected. LGLs decreased in response to treatment with cyclosporine-A (CsA), but the cycling of the platelet count continued. This is the first report of cyclic thrombocytopenia associated with a T-LGL lymphoproliferative disorder.
authors.affiliation: Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA. pfogarty@medicine.ucsf.edu
authors.forename: Patrick F
authors.initials: PF
authors.lastname: Fogarty
authors.forename: Maryalice
authors.initials: M
authors.lastname: Stetler-Stevenson
authors.forename: Aloysius
authors.initials: A
authors.lastname: Pereira
authors.forename: Cynthia E
authors.initials: CE
authors.lastname: Dunbar
mesh_terms: D000328:Adult; D015334:Gene Rearrangement, gamma-Chain T-Cell Antigen Receptor; D006801:Humans; D008232:Lymphoproliferative Disorders / Q000097:blood / Q000150:complications / Q000235:genetics / Q000276:immunology*; D008297:Male; D010976:Platelet Count; D011696:Purpura, Thrombocytopenic / Q000097:blood / Q000150:complications / Q000276:immunology* / Q000628:therapy; D016176:T-Lymphocyte Subsets / Q000276:immunology*