Objective: Brucellosis, which is a chronic infectious bacterial disease. We aimed to show the association of serum ‘A PRoliferation-Inducing Ligand (APRIL) (TNFSF13A)’ and ‘B-cell Activating Factor belonging to the tumor necrosis factor family (BAFF)’ levels in children with acute brucellosis.

Methods: Fifty children with acute brucellosis and 35 healthy controls, who were admitted during a two-year period between 2018 and 2020, were prospectively included. All patients and healthy children were tested for complete blood count, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), BAFF, and APRIL.

Results: The mean age of 50 patients with acute brucellosis was 10.2±3.6 years, and thirty-seven (74%) of them was male. BAFF levels were significantly higher in children with acute brucellosis than the control group (548.6±253.4 vs. 280.5±83.6, p<0.001). Other laboratory tests, in addition to APRIL levels were not statistically different between the patients and control group. Neither BAFF and APRIL, nor age, gender, Rose Bengal, transaminase levels, and other laboratory parameters were significantly different between the patients with and without any complication. ROC analysis showed that BAFF values over than 330 pg/mL were 78% sensitivite and 72% specific to detect acute brucellosis in children (Area under curve: 0.864, p<0.001, CI: 0.787-0.941) (Figure 1).

Conclusion: BAFF levels are significantly elevated in children with acute brucellosis. BAFF levels over than 330 pg/mL are 78% sensitivite and 72% specific to detect the disease, but BAFF cannot discriminate between patients with and without complications. APRIL, which has relatively similar effects, is not associated with acute pediatric brucellosis.

Keywords: APRIL, BAFF, biomarker, brucellosis