The performance of different classification criteria in paediatric Behçet's disease

Behçet's disease (BD) is a variable vessel vasculitis. The most widely used classification criteria for adults is the International Behçet's Study Group (ISG) criteria. Recently, the paediatric BD (PEDBD) classification criteria has been developed for children. For disease activity, there are mainly two severity scores; the Iranian BD dynamic activity measure (IBDDAM) and BD current activity form (BDCAF). We tested the performances of PEDBD and ISG criteria and the correlation between severity scores and physician global assessment (PGA) in children with BD.

Thirty BD patients from Hacettepe University, Ankara, Turkey; 24 from Erciyes University, Kayseri, Turkey; and 14 BD patients from Rambam Medical Centre, Haifa, Israel were included. As controls, children with systemic lupus erythematosus, polyarteritis nodosa, and Crohn disease from Turkey and Israel were included. The sensitivity and specificity of the PEDBD and ISG criteria were evaluated based on the features of the patients before or at 16 years of age. The gold standard for the diagnosis of BD was based on expert opinion at each centre. Expert PGA (visual analogue scale between 0-10; where 0 indicates no disease activity), IBDDAM, and BDCAF were evaluated at the time of diagnosis and at last follow-up in all patients.

Sixty-eight BD (disease onset≤16 years; 44.1% male) and 90 control patients were included. The sensitivity and specificity of PEDBD/ISG criteria were 73.5%/52.9% and 97.7%/100%, respectively. Thirty-two (47%) patients with BD failed to fulfill ISG criteria while almost all met PEDBD criteria. The median (interquartile range; IQR) IBDDAM and BDCAF scores at diagnosis were 6(4)/4(2); significantly decreased to 1(2)/1(2), respectively at latest follow-up (p<0.001 for both). The median (IQR) PGA score at diagnosis was 5(2); significantly decreased to 1(2) at latest follow-up (p<0.001). IBDDAM positively correlated with BDCAF (r=0.637; p<0.001). PGA positively correlated with BDCAF and IBDDAM (r=0.502; p<0.001 and r=0.624;p<0.001, respectively).

In our study, the PEDBD criteria showed better sensitivity than ISG criteria which is a big advantage for paediatric patients for early diagnosis. We also demonstrated that the severity scores were positively correlated with each other and PGA; thus may be used in clinical practice for paediatric BD patients.