title: Monoclonal T-cell dyscrasia of undetermined significance associated with recalcitrant erythroderma.
abstract: BACKGROUND
  Erythroderma is a diffuse, inflammatory skin reaction that, in rare instances, is associated with hematologic malignancies such as cutaneous T-cell lymphoma (erythrodermic mycosis fungoides) or T-cell leukemia (Sezary syndrome or adult T-cell leukemia/lymphoma).
  
  
  METHODS
  We screened 30 patients with erythroderma (20 patients with erythroderma of known etiology and 10 patients with idiopathic erythroderma) for the presence of circulating monoclonal T-lymphocyte populations using T-cell receptor (TCR)-gamma gene-specific polymerase chain reaction and automated capillary DNA electrophoresis. Moreover, the phenotypic analysis of peripheral blood CD4+ lymphocytes was performed using the following surface markers: CD3, CD7, CD8, CD25, CD26, CD27, CD28, CD29, CD30, CD45RO, CD45RA, CD56, CD134, HLA-DR, TCRalphabeta, TCRgammadelta, and cutaneous lymphocyte antigen (CLA). In 5 patients with idiopathic erythroderma we detected T-cell clones in peripheral blood (in 1 case, associated with the presence of the same clone in the skin) and a 2-fold increase in the proportion of CD3+ CD4+ CD7- CD26- cells. Cell depletion studies indicated that the monoclonal T cells were present within the CD4+ CD7- cell population. Clinically, all patients had chronic, recalcitrant erythroderma but none developed any hematological malignancy during their lifetimes or fulfilled the criteria for cutaneous lymphoma or Sezary syndrome.
  
  
  CONCLUSIONS
  A proportion of patients with chronic erythroderma present with the monoclonal expansion of CD4+ CD7- CD26- lymphocytes in their blood. This condition represents a probably benign T-cell dyscrasia, or one of very low malignancy. Alongside monoclonal gammapathy of undetermined significance (MGUS) and monoclonal (B-cell) lymphocytosis of undetermined significance (MLUS), we propose using monoclonal T-cell dyscrasia of undetermined significance (MTUS) to underline a conceptual similarity between this disorder and the more common types of lymphocytic dyscrasia.
authors.affiliation: Department of Dermatology, Bispebjerg Hospital, University of Copenhagen, Denmark. rg01@bbh.hosp.dk
authors.forename: Robert
authors.initials: R
authors.lastname: Gniadecki
authors.forename: Ansgar
authors.initials: A
authors.lastname: Lukowsky
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000032:analysis / Q000276:immunology*; D016022:Case-Control Studies; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D015331:Cohort Studies; D003873:Dermatitis, Exfoliative / Q000276:immunology / Q000473:pathology*; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D008213:Lymphocyte Activation; D016410:Lymphoma, T-Cell, Cutaneous / Q000276:immunology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011230:Precancerous Conditions / Q000235:genetics / Q000473:pathology*; D011379:Prognosis; D011948:Receptors, Antigen, T-Cell / Q000032:analysis / Q000276:immunology; D018570:Risk Assessment; D012878:Skin Neoplasms / Q000276:immunology / Q000473:pathology*
chemical_list: D015703:Antigens, CD; D011948:Receptors, Antigen, T-Cell