title: Hydrochlorothiazide and cutaneous T cell lymphoma: prospective analysis and case series.
abstract: BACKGROUND
  Mycosis fungoides (MF) and leukemic Sézary syndrome (SS) are the most common cutaneous T cell lymphomas (CTCL), but their etiology remains unknown. After patients were observed with hydrochlorothiazide (HCTZ)-associated CTCL, HCTZ was examined as a putative chronic antigen in a cohort of prospectively staged patients.
  
  
  METHODS
  Demographic and drug exposure data was examined from 1443 confirmed MF and SS patients. Hypertensive CTCL patients were divided into HCTZ users or nonusers for statistical analysis by chi-square and t tests. Causality in a case series was rated by the Naranjo Adverse Drug Reaction Probability Scale.
  
  
  RESULTS
  A total of 815 of 1443 MF and SS patients (56.5%) were hypertensive; 205 (25.2%) were taking HCTZ at initial staging. Comparing stage of patients who were using or not using HCTZ, the most significant difference was between stage I and stage IV (odds ratio of 0.45; 95% confidence interval of 0.25-0.78, P = .003), demonstrating reduced likelihood of being stage IV in patients who were on HCTZ. Seventy-seven percent of the MF patients on HCTZ were stage I. A total of 125 patients of 196 (63.8%) started HCTZ prior to developing CTCL lesions, and 35 of 121 (28.0%) started within 1 year of first skin rash. Thirty-six of 125 patients (28.8%) experienced complete or partial remissions after discontinuing HCTZ. A monoclonal T cell receptor rearrangement was detected more frequently in the hypertensive stage I patients not taking HCTZ as compared with those who were (55.3% vs 69.1%, P = .032). Three patients were rechallenged and developed MF lesions that resolved or improved with discontinuation.
  
  
  CONCLUSIONS
  HCTZ is commonly prescribed and may be a putative antigen in a small subset of early MF patients. Careful drug histories and a trial off medication are warranted.
authors.affiliation: Department of Dermatology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Richard R
authors.initials: RR
authors.lastname: Jahan-Tigh
authors.forename: Auris O
authors.initials: AO
authors.lastname: Huen
authors.forename: Grace L
authors.initials: GL
authors.lastname: Lee
authors.forename: Jenny V
authors.initials: JV
authors.lastname: Pozadzides
authors.forename: Ping
authors.initials: P
authors.lastname: Liu
authors.forename: Madeleine
authors.initials: M
authors.lastname: Duvic
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000009:adverse effects* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D006852:Hydrochlorothiazide / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009182:Mycosis Fungoides / Q000209:etiology* / Q000276:immunology; D011446:Prospective Studies; D012751:Sezary Syndrome / Q000209:etiology* / Q000276:immunology; D012878:Skin Neoplasms / Q000209:etiology* / Q000276:immunology
chemical_list: D000959:Antihypertensive Agents; D006852:Hydrochlorothiazide