title: Dealing with immunogenicity of biologicals: assessment and   clinical relevance.
abstract: OBJECTIVE
  In the last decade, biologicals revolutionized rheumatology. An increasing number of patients benefit from biotherapeuticals. However, some patients do not respond to treatment and others lose their response after a certain time. Immunogenicity is one of the factors linked to secondary nonresponse but its clinical significance has remained controversial.
  
  
  RESULTS
  In recent years, knowledge of how to assess immunogenicity of biologicals has improved. Various reports show an inverse relationship between drug levels and antibody formation against the drug. Studies associated immunogenicity of therapeutic antibodies with clinically significant nonresponse in a subgroup of patients. Clinically relevant immunogenicity is influenced by several factors including dosing and concomitant medication. It has been shown that immunogenicity against biologicals can be persistent or transient.
  
  
  CONCLUSIONS
  Immunogenicity affects a significant number of patients treated with biologicals. Monitoring of drug levels as well as of antibodies against therapeutic antibodies may lead to more rational treatment strategies.
authors.affiliation: Department of Rheumatology, Jan van Breemen Institute, Dr Jan van Breemenstraat 2, Amsterdam 1056 AB, The Netherlands. g.wolbink@janvanbreemen.nl
authors.forename: Gerrit J
authors.initials: GJ
authors.lastname: Wolbink
authors.forename: Lucien A
authors.initials: LA
authors.lastname: Aarden
authors.forename: B A C
authors.initials: BA
authors.lastname: Dijkmans
mesh_terms: D000906:Antibodies / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D000888:Antibodies, Anti-Idiotypic / Q000096:biosynthesis; D001688:Biological Products / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology* / Q000493:pharmacokinetics; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage; D018448:Models, Immunological; D012216:Rheumatic Diseases / Q000276:immunology* / Q000628:therapy*
chemical_list: D000906:Antibodies; D000888:Antibodies, Anti-Idiotypic; D001688:Biological Products; D007166:Immunosuppressive Agents