OBJECTIVE: Juvenil idiopathic arthritis (JIA) is the most common chronic rheumatic disease in children. One of the hematologic involvement among patients with JIA is anemia. The mechanism of anemia in children with JIA is overproduction of hepcidin due to the influence of pro-inflammatory cytokines.  Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were used as markers of inflammatory activity. We aimed to identify the relationship between hemoglobin level and markers of inflammation in children with JIA at Dr. Kariadi Hospital. 
METHOD: This was a retrospective study of 11 children with JIA at Dr. Kariadi Hospital from 2016-2018. We collected general characteristic and hemoglobin level, ESR and CRP concentration as markers of inflammation. Data were analyzed by Spearman correlation test. 
RESULT: Among 11 children with JIA (8 boys, 3 girls), anemia was found in 8 children (72.7%). Oligoarthritis was the most frequent subtype (72.7%). Polyarthritis, systemic and psoriatic arthritis were found in 1 child (9.1%), respectively. Median duration of the disease was 8 weeks (4-24 weeks). Mean of hemoglobin level was 9.67 g/dl, with the lowest hemoglobin level of 7 g/dl and the highest 12 g/dl. Median 1 hour and 2 hours ESR concentration was 117 mm/h (27-132 mm/h) and 129 mm/h (53-140 mm/h), respectively. Median CRP concentration was 2.64 mg/L (0.06-25.86 mg/L). Hemoglobin level was significantly associated with higher 1 hour (p=0.004, r=-0.782) and 2 hours ESR (p=0.004, r=-0.782), respectively. No significant correlation was found between hemoglobin level with CRP concentration (p=0.066, r=-0.573).
CONCLUSION: Hemoglobin level was correlated with ESR, as marker of inflammation.