title: Serum sickness with an elevated level of human anti-chimeric antibody following treatment with rituximab in a child with chronic immune thrombocytopenic purpura.
abstract: Rituximab, a chimeric murine/human monoclonal anti-CD20 antibody, was licensed for the treatment of B-cell lymphoma and has also shown efficacy against autoimmune diseases such as immune thrombocytopenic purpura (ITP). It is relatively safe; however, about 1-20% of patients were reported to have developed rituximab-induced serum sickness, which is more common among patients with autoimmune conditions than among those with hematologic malignancies. Here we describe a pediatric patient with steroid-dependent chronic ITP who presented with arthralgia and fever ten days after the second infusion of rituximab (on day 10), and presented with malaise and maculopapular rash on day 21. Oral prednisolone was started and his symptoms resolved. He had an elevated level of human anti-chimeric antibody (HACA) on day 27; thereafter, the HACA level slowly decreased. To our knowledge, among pediatric patients who received rituximab for chronic ITP, this is the sixth documented case of serum sickness and the only one who manifested an elevated level of HACA. Rituximab is a beneficial treatment option against chronic ITP; however, the risk of serum sickness should be considered. Steroid, usually used for the treatment of serum sickness, may prevent the development of severe serum sickness when administered during and after rituximab treatment.
authors.affiliation: Department of Pediatrics, Saiseikai Yokohamashi Nanbu Hospital, 3-2-10 Kounanndai Kounan-ku, Yokohama, 234-8503, Japan. sgoto49@aol.com.
authors.forename: Shoko
authors.initials: S
authors.lastname: Goto
authors.affiliation: Department of Pediatrics, Yokohama City University, Yokohama, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Goto
authors.affiliation: Department of Pediatrics, Saiseikai Yokohamashi Nanbu Hospital, 3-2-10 Kounanndai Kounan-ku, Yokohama, 234-8503, Japan.
authors.forename: Reo
authors.initials: R
authors.lastname: Tanoshima
authors.affiliation: Department of Pediatrics, Saiseikai Yokohamashi Nanbu Hospital, 3-2-10 Kounanndai Kounan-ku, Yokohama, 234-8503, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kato
authors.affiliation: Department of Pediatrics, Saiseikai Yokohamashi Nanbu Hospital, 3-2-10 Kounanndai Kounan-ku, Yokohama, 234-8503, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takahashi
authors.affiliation: Department of Orthopedics, Saiseikai Yokohamashi Nanbu Hospital, Yokohama, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Sekiguchi
authors.affiliation: Department of Pediatrics, Saiseikai Yokohamashi Nanbu Hospital, 3-2-10 Kounanndai Kounan-ku, Yokohama, 234-8503, Japan.
authors.forename: Sumio
authors.initials: S
authors.lastname: Kai
mesh_terms: D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000627:therapeutic use*; D058846:Antibodies, Monoclonal, Murine-Derived; D002648:Child; D002908:Chronic Disease; D006801:Humans; D007167:Immunotherapy; D008297:Male; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000188:drug therapy* / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000097:blood* / Q000276:immunology*; D000069283:Rituximab
chemical_list: D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D011993:Recombinant Fusion Proteins; D000069283:Rituximab