title: Basophil Activation Test is a Relevant Biomarker of the Outcome of Rapid Desensitization in Platinum Compounds-Allergy.
abstract: BACKGROUND
  Rapid drug desensitization (RDD) has become a cornerstone in the management of immediate drug hypersensitivity reactions (DHRs) to chemotherapeutic agents. Because of the inherent risk of anaphylaxis during RDD, biomarkers to predict patients at risk of developing such severe reactions are needed. The basophil activation test (BAT) has been used in DHRs as a diagnostic tool.
  
  
  OBJECTIVE
  We evaluated basophil CD63 and CD203c expression (BAT) as a biomarker to assess the safety and effectiveness of RDD in platinum compounds-allergic patients.
  
  
  METHODS
  Patients allergic to platinum compounds (n = 15) undergoing RDD were assessed through clinical history, skin testing, serum tryptase levels, and BAT. BAT was performed immediately before RDD, assessing CD203c and CD63 expression on basophils. BAT was also performed in 6 patients tolerant to platinum compounds and in 6 healthy volunteers.
  
  
  RESULTS
  BAT was positive to CD203c or CD63 in 11 out of 15 patients allergic to platinum compounds (73%), with increased expression of CD203c and CD63 in 11 (73%) and 6 (40%) patients, respectively. Increased CD63 expression tended to be associated with more severe initial reactions. All controls had negative test results. Reactions during RDD were associated with BAT positivity and increased tryptase levels. Only 1 of 4 patients with negative BAT had a mild reaction during RDD. BAT remained positive in multiple sequential RDD.
  
  
  CONCLUSIONS
  BAT identified patients allergic to platinum compounds with an increased risk of reactions during desensitization and higher CD63 expression was observed in severe reactions. Multiple RDDs to platinum compounds did not induce persistent hyporesponsiveness on basophils. BAT is a potential biomarker for RDD.
authors.affiliation: Division of Rheumatology, Immunology and Allergy, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass; Clinical Immunology and Allergy Division, University of São Paulo, São Paulo, Brazil. Electronic address: pbianchi@usp.br.
authors.forename: Pedro
authors.initials: P
authors.lastname: Giavina-Bianchi
authors.affiliation: Division of Rheumatology, Immunology and Allergy, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass; Clinical Immunology and Allergy Division, University of São Paulo, São Paulo, Brazil.
authors.forename: Violeta Régnier
authors.initials: VR
authors.lastname: Galvão
authors.affiliation: Division of Rheumatology, Immunology and Allergy, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass; Division of Allergy and Immunology, Department of Medicine, Hôpital Maisonneuve-Rosemont, Université de Montreal, Montreal, Canada.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Picard
authors.affiliation: Division of Rheumatology, Immunology and Allergy, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass; Immunoallergology Department, Hospital de Santa Maria/Centro Hospitalar Lisboa Norte, Lisbon, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Caiado
authors.affiliation: Division of Rheumatology, Immunology and Allergy, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass.
authors.forename: Mariana C
authors.initials: MC
authors.lastname: Castells
mesh_terms: D000328:Adult; D000485:Allergens / Q000276:immunology*; D000707:Anaphylaxis / Q000209:etiology / Q000517:prevention & control*; D000970:Antineoplastic Agents / Q000276:immunology*; D015549:Basophil Degranulation Test / Q000379:methods*; D001491:Basophils / Q000276:immunology*; D015415:Biomarkers / Q000378:metabolism; D003888:Desensitization, Immunologic / Q000379:methods*; D004342:Drug Hypersensitivity / Q000150:complications / Q000175:diagnosis*; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000150:complications / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D017671:Platinum Compounds / Q000276:immunology*; D011755:Pyrophosphatases / Q000378:metabolism; D060149:Tetraspanin 30 / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D000485:Allergens; D000970:Antineoplastic Agents; D015415:Biomarkers; C427944:ENPP3 protein, human; D017671:Platinum Compounds; D060149:Tetraspanin 30; D010727:Phosphoric Diester Hydrolases; D011755:Pyrophosphatases
keywords: Anaphylaxis; Basophil activation test; Drug allergy; Platinum compounds; Rapid drug desensitization