ab1904

Anti-keratin antibodies in patients with juvenile idiopathic arthritis

I. Hromadíková, P. Vavrincova, K. Stechova, D. Hridelova

2nd Paediatric Clinic, University Hospital Motol, Prague , Czech Republic Ilona Hromadnikova, MSc, PhD., Pavla Vavrincova PhD., Katerina Stechova, MD, Dana Hridelova.

ABSTRACT
Objective
We discuss the presence of anti-keratin antibodies (AKA) of the IgG class in patients with defined juvenile idiopathic arthritis (JIA).

Methods
An indirect immunofluorescence test with rat oesophagus substrate was used for the detection and quantification of AKA antibodies in patients' sera.

Results
Overall 30/60 patients with JIA had sera positive for AKA (50%, p=0,0005) ranging from 1:20 to 1:160 dilutions. Using the classification criteria for childhood idiopathic arthritis, AKA occurred in 2/7 patients with systemic disease (28.6%), in 13/30 patients with RF negative polyarthritis (43.3%, p=0.008) and in 12/18 RF positive polyarthritis (66.7%, p=0.002). AKA were also found in a small cohort of patients with oligoarthritis (1/3) and psoriatic arthritis (2/2). AKA positivity occurred in 3/26 healthy controls at a 1:20 dilution. The presence of AKA was correlated as well as with the severity of the disease. Our study revealed that AKA was present overall in 16/29 patients (55.2%) with severe JIA and in 11/26 patients (42.3%) with non-severe disease. We also observed that AKA remained positive regardless of disease activity. AKA were detectable in 44.4% patients with active JIA and in 45.9% patients in the complete or near remission.

Conclusion
Our data suggest that AKA are present in patients with JIA. However, no correlation with severity or disease activity was observed.

Key words
Anti-keratin antibodies, indirect immunofluorescence, juvenile idiopathic arthritis, rat esophagus.

This research was supported by a grant from the 2nd Medical Faculty, Charles University in Prague, VZ no. 111300003 and by the 5th Framework Programme, EUROBANK, no. QLRI-2000-00010.
Please address correspondence to: Ilona Hromadníková, MSc, PhD, 2nd Department of Paediatrics, University Hospital Motol, Prague, V Uvalu 84, 150 06 Prague 5, Czech Republic.
E-mail: ilona.hromadnikova@lfmotol.cuni.cz