title: Anti-ribosomal P antibody: a multicenter study in childhood-onset systemic lupus erythematosus patients.
abstract: Objectives Anti-ribosomal P protein (anti-P) autoantibodies are highly specific for systemic lupus erythematosus (SLE). However, the evaluation of this autoantibody in childhood-onset SLE (cSLE) populations has been limited to a few small series, hampering the interpretation of the clinical and laboratorial associations. Therefore, the objective of this multicenter cohort study was to evaluate demographic, clinical/laboratorial features, and disease damage score in cSLE patients with and without the presence of anti-P antibody. Methods This was a retrospective multicenter study performed in 10 pediatric rheumatology services of São Paulo state, Brazil. Anti-P antibodies were measured by ELISA in 228 cSLE patients. Results Anti-P antibodies were observed in 61/228 (27%) cSLE patients. Frequencies of cumulative lymphadenopathy (29% vs. 15%, p = 0.014), acute confusional state (13% vs. 5%, p = 0.041), mood disorder (18% vs. 8%, p = 0.041), autoimmune hemolytic anemia (34% vs. 15%, p = 0.001), as well as presence of anti-Sm (67% vs. 40%, p = 0.001), anti-RNP (39% vs. 21%, p = 0.012) and anti-Ro/SSA antibodies (43% vs. 25%, p = 0.016) were significantly higher in cSLE patients with anti-P antibodies compared to those without these autoantibodies. A multiple regression model revealed that anti-P antibodies were associated with autoimmune hemolytic anemia (odds ratio (OR) = 2.758, 95% confidence interval (CI): 1.304-5.833, p = 0.008) and anti-Sm antibody (OR = 2.719, 95% CI: 1.365-5.418, p = 0.004). The SLICC/ACR damage index was comparable in patients with and without anti-P antibodies ( p = 0.780). Conclusions The novel association of anti-P antibodies and autoimmune hemolytic anemia was evidenced in cSLE patients and further studies are necessary to determine if anti-P titers may vary with this hematological manifestation.
authors.affiliation: 1 Pediatric Rheumatology Unit, Children's Institute, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Brazil.
authors.forename: C C M
authors.initials: CC
authors.lastname: Valões
authors.affiliation: 1 Pediatric Rheumatology Unit, Children's Institute, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Brazil.
authors.forename: B C
authors.initials: BC
authors.lastname: Molinari
authors.affiliation: 1 Pediatric Rheumatology Unit, Children's Institute, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Brazil.
authors.forename: A C G
authors.initials: AC
authors.lastname: Pitta
authors.affiliation: 1 Pediatric Rheumatology Unit, Children's Institute, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Brazil.|2 Division of Rheumatology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Brazil.
authors.forename: N W S
authors.initials: NW
authors.lastname: Gormezano
authors.affiliation: 1 Pediatric Rheumatology Unit, Children's Institute, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Brazil.
authors.forename: S C L
authors.initials: SC
authors.lastname: Farhat
authors.affiliation: 1 Pediatric Rheumatology Unit, Children's Institute, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Brazil.
authors.forename: K
authors.initials: K
authors.lastname: Kozu
authors.affiliation: 1 Pediatric Rheumatology Unit, Children's Institute, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Brazil.
authors.forename: A M E
authors.initials: AM
authors.lastname: Sallum
authors.affiliation: 3 Pediatric Rheumatology Unit, State University of Campinas (UNICAMP), Brazil.
authors.forename: S
authors.initials: S
authors.lastname: Appenzeller
authors.affiliation: 4 Pediatric Rheumatology Unit, Universidade Federal de São Paulo (UNIFESP), Brazil.
authors.forename: A P
authors.initials: AP
authors.lastname: Sakamoto
authors.affiliation: 4 Pediatric Rheumatology Unit, Universidade Federal de São Paulo (UNIFESP), Brazil.
authors.forename: M T
authors.initials: MT
authors.lastname: Terreri
authors.affiliation: 2 Division of Rheumatology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Brazil.
authors.forename: R M R
authors.initials: RM
authors.lastname: Pereira
authors.affiliation: 5 Pediatric Rheumatology Division, São Paulo State University (UNESP) - Faculdade de Medicina de Botucatu, Brazil.
authors.forename: C S
authors.initials: CS
authors.lastname: Magalhães
authors.affiliation: 1 Pediatric Rheumatology Unit, Children's Institute, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Brazil.
authors.forename: J C O A
authors.initials: JC
authors.lastname: Ferreira
authors.affiliation: 6 Pediatric Rheumatology Unit, Hospital Darcy Vargas, Brazil.
authors.forename: C M
authors.initials: CM
authors.lastname: Barbosa
authors.affiliation: 7 Pediatric Rheumatology Unit, Ribeirão Preto Medical School - FMUSP, Brazil.
authors.forename: F H
authors.initials: FH
authors.lastname: Gomes
authors.affiliation: 2 Division of Rheumatology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Brazil.
authors.forename: E
authors.initials: E
authors.lastname: Bonfá
authors.affiliation: 1 Pediatric Rheumatology Unit, Children's Institute, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Brazil.|2 Division of Rheumatology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Brazil.
authors.forename: C A
authors.initials: CA
authors.lastname: Silva
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D000744:Anemia, Hemolytic, Autoimmune / Q000453:epidemiology* / Q000276:immunology; D001323:Autoantibodies / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000150:complications* / Q000276:immunology / Q000523:psychology; D008297:Male; D019964:Mood Disorders / Q000453:epidemiology*; D012044:Regression Analysis; D012189:Retrospective Studies; D012269:Ribosomal Proteins / Q000276:immunology*; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D012269:Ribosomal Proteins
keywords: Systemic lupus erythematosus; anti- ribosomal P protein antibodies; autoimmune hemolytic anemia; childhood; neuropsychiatric lupus