title: NK and NKT cell dynamics after rituximab therapy for systemic lupus erythematosus and rheumatoid arthritis.
abstract: Biomarkers of clinical response to rituximab (RTX) therapy and early predictors of outcome are still under investigation. We report a flow cytometric immunophenotyping analysis from peripheral blood leukocyte subpopulations of two patients with systemic lupus erythematosus (SLE) associated thrombocytopenia and one patient with rheumatoid arthritis (RA), before and after 6 weeks of treatment with RTX. Our results show a reduced population of CD19(+) expressing cells (B cells) after RTX treatment in all three patients. Increased frequency of peripheral regulatory CD4(+)CD25(high) T cell subset and the CD3(-)CD16(-)CD56(bright) NK cell subset after RTX therapy were also observed in all patients, the latter being more pronounced in the SLE patient with sustained clinical response. In addition, an increased population of NKT cell subsets was observed in the patients with clinical response. This is the first evaluation of NK and NKT cells as biomarkers of clinical response after rituximab therapy in rheumatic diseases.
authors.affiliation: Oswaldo Cruz Foundation, Salvador, Brazil.
authors.forename: Eliana A G
authors.initials: EA
authors.lastname: Reis
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Athanazio
authors.forename: Isabella
authors.initials: I
authors.lastname: Lima
authors.forename: Natália
authors.initials: N
authors.lastname: Oliveira e Silva
authors.forename: Jorge Clarencio S
authors.initials: JC
authors.lastname: Andrade
authors.forename: Ronden N
authors.initials: RN
authors.lastname: Jesus
authors.forename: Lúcio M
authors.initials: LM
authors.lastname: Barbosa
authors.forename: Mitermayer G
authors.initials: MG
authors.lastname: Reis
authors.forename: Mittermayer B
authors.initials: MB
authors.lastname: Santiago
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000627:therapeutic use*; D058846:Antibodies, Monoclonal, Murine-Derived; D018501:Antirheumatic Agents / Q000276:immunology / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D008875:Middle Aged; D055611:Natural Killer T-Cells / Q000276:immunology*; D000069283:Rituximab
chemical_list: D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D018501:Antirheumatic Agents; D000069283:Rituximab