Gamma-glutamyl transpeptidase level is correlated with disease activity in oligoarticular and polyarticular juvenile idiopathic arthritis

Abstract Introduction Gamma-glutamyl transpeptidase (GGT) level was found to be correlated with disease activity indexes in rheumatoid arthritis [1]. This association was not yet investigated in children with oligoarticular and polyarticular Juvenile idiopathic arthritis (JIA). Objectives The present study aims to investigate the correlation between GGT level and disease-related parameters in oligoarticular and polyarticular JIA. Methods We performed a retrospective study including patients with oligoarticular and polyarticular JIA responding to the 2001 International League of Associations for Rheumatology (ILAR) classification. Sociodemographic, disease-related parameters (age of onset, disease duration, patient global assessment (PGA), Pain Visual Analogue Scale (VAS), C-Reactive protein (CRP) level, Erythrocyte Sedimentation Rate (ESR), disease activity assessed using the Juvenile Arthritis Disease Activity Score (JADAS) based on ESR), and GGT level were collected. Continuous variables were expressed with median and Interquartile range (IQR). Spearman correlation was used to assess the association between GGT levels and disease-related data. Results Eleven patients were included with a median age of 12 (IQR: 10–15) years and 8 females. Median disease duration was 4 (IQR: 4–7) years and median age of onset was 8 (IQR: 5–10) years. Five patients had oligoarticular JIA, 3 had a polyarticular with positive Rheumatoid Factor (RF) form, 2 had a polyarticular with negative RF form and one had an undifferentiated JIA. Median JADAS was 3.6 (IQR: 0–9). Median ESR, CRP, and GGT levels were 14 (10–19) mm/H, 1.8 (2–6.4) mg/l, and 14 (12–16) IU/l, respectively. A strong positive correlation was found between GGT level and JADAS (r = 0.749, P = 0.008). Level of CRP and ESR were not correlated with GGT level. Besides, patient global assessment and pain VAS were positively correlated with GGT level (r = 0.670, P = 0.049; r = 0.814, P = 0.014, respectively). No correlation was found between GGT level and disease duration and number of tender or swollen joints. Conclusion The GGT level was significantly higher in patients with more active disease, higher pain, and global assessment. This suggests that GGT level can be used as a marker of disease activity as in JIA. References 1 Vergneault H, Vandebeuque E, Codullo V, Allanore Y, Avouac J. Disease Activity Score-28 using γGT permits a dual evaluation of joint activity and cardiovascular risk. J Rheumatol 2020.