title: Optimization of 90 Y-antiCD20 preparation for radioimmunotherapy.
abstract: BACKGROUND
  The advent of monoclonal antibodies such as Rituximab, in recent years, has brought about decisive progress in the treatment of aggressive and indolent non-Hodgkin's lymphoma.
  
  
  OBJECTIVE
  A further tried and tested improvement to the unmodified antibody has been its coupling to the beta-emitters Y-90. The optimization of 90 Y-antiCD20 radioimmunoconjugate production and quality control methods for future clinical studies in the country was targeted in this work.
  
  
  METHODS
  The antibody was labeled with 90 Y-yttrium chloride (185 MBq) after conjugation with freshly prepared ccDTPA. Y-90 chloride was obtained by thermal neutron flux (4 × 10 13 n/cm 2 /s) of a natural Y 2 O 3 sample, dissolved in acidic media. Radiolabeling was completed in 24 h by the addition of DTPA-Rituximab conjugate at room temperature.
  
  
  METHODS
  All values were expressed as mean ± standard deviation (mean ± SD), and the data were compared using Student's t-test. Statistical significance was defined as P < 0.05.
  
  
  RESULTS
  Radiochemical purity of 96% was obtained by using ITLC method for the final radioimmunoconjugate (specific activity = 440-480 MBq/mg). The final isotonic 90 Y-Rituximab complex was checked by gel electrophoresis for protein integrity retention. Biodistribution studies in normal rats were carried out to determine the radioimmunoconjugate distribution up to 72 h.
  
  
  CONCLUSIONS
  The results showed that 90 Y-DTPA-Rituximab could be considered for further evaluation in animals and possibly in humans as a radiopharmaceutical for use in radioimmunotherapy against non-Hodgkin's lymphomas. Because of the importance of developing anti-lymphoma B agents in nuclear medicine for country use, an optimized radiolabeling method has been introduced.
authors.affiliation: Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Nazila
authors.initials: N
authors.lastname: Gholipour
authors.forename: Ariandokht
authors.initials: A
authors.lastname: Vakili
authors.forename: Edalat
authors.initials: E
authors.lastname: Radfar
authors.forename: Amir Reza
authors.initials: AR
authors.lastname: Jalilian
authors.forename: Ali
authors.initials: A
authors.lastname: Bahrami-Samani
authors.forename: Simindokht
authors.initials: S
authors.lastname: Shirvani-Arani
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ghannadi-Maragheh
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000276:immunology*; D058846:Antibodies, Monoclonal, Murine-Derived / Q000008:administration & dosage / Q000276:immunology; D018951:Antigens, CD20 / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D018796:Immunoconjugates / Q000008:administration & dosage* / Q000276:immunology; D008228:Lymphoma, Non-Hodgkin / Q000276:immunology / Q000532:radiotherapy; D008297:Male; D004369:Pentetic Acid / Q000008:administration & dosage / Q000276:immunology; D016499:Radioimmunotherapy / Q000379:methods*; D019275:Radiopharmaceuticals / Q000008:administration & dosage / Q000276:immunology; D051381:Rats; D000069283:Rituximab; D015021:Yttrium Radioisotopes / Q000008:administration & dosage*
chemical_list: D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D018951:Antigens, CD20; D018796:Immunoconjugates; D019275:Radiopharmaceuticals; D015021:Yttrium Radioisotopes; D000069283:Rituximab; D004369:Pentetic Acid