Early typing diagnostic and predictive value of AKA, APF and ACPA in juvenile idiopathic arthritis / 中华检验医学杂志

ABSTRACT

Objective To investigate the early typing diagnostic and predictive value of anti-keratin antibodies(AKA), anti-perinuclear factor(APF) and anti-citrullinated protein antibodies(ACPA) in patients of juvenile idiopathic arthritis (JIA). Methods A retrospective study was conducted to collect 144 cases of JIA who were hospitalized in Capital Institute of Pediatrics from December 2013 to June 2016 and followed up for at least one year.Among them,66 were males (46％) and 78 were females (54％).The age at diagnosis was between 1 year 5 months to 15 years 9 months.144 patients were tested for AKA,ACPA,APF and TNFα upon admission. Chi-square test or Fisher exact test were used to compare the positive rates of three antibodies among different subtypes. Mann-Whitney nonparametric test and Chi-square test or Fisher exact test were used to analyze the data of prognosis between antibody-positive group and antibody-negative group in the course of disease. Results In 144 patients, 49(34％) were classified as systemic arthritis, 28 (19.4％) as polyarthritis, 61(42.3％) as oligoarthritis, and 6(4.2％) as enthesitis-associated arthritis. 52 cases (36.1％) were positive for one antibody or more antibodies of AKA/APF/ACPA at the early stage,14(9.7％) were AKA positive, 44(30.6％) were ACPA positive and 12(8.3％) were APF positive. The positive rates of ACPA/AKA/APF antibodies were significantly different among different subtypes(χ2=33.863,26.860,14.395;P<0.01,<0.01,<0.05).The rates in polyarthritis were higher than those in systemic arthritis and oligoarthritis;In 95 children with non-systemic form,the level of TNFαin antibody-positive group(43 cases)was higher than that in antibody-negative group(52 cases)at the early stage(Z=4.785, P<0.01);144 patients were followed up for at least one year,the rates of patients who accepted biologic therapies were significantly different between antibody-positive group and antibody-negative group (50％ vs 25％). So do the rates of patients with joint deformities(17.3％vs 2.2％)and with important joints involvement (hip and axis joints)(59.6％vs 14.1％)(χ2=9.249, 10.875, 32.392; P<0.01, <0.01, <0.01). Further more, the number of joints involved in the antibody-positive group (7.07 ± 3.85) was significantly more than that in the antibody-negative group (2.31 ± 1.64)(F=63.822,P<0.01). Conclusions AKA,APF and ACPA are important in the early typing diagnosis of JIA,and may be closely related to the prognosis of patients with JIA.