Galectin-3: a new biomarker for differentiating periodic fever, adenitis, pharyngitis, aphthous stomatitis (PFAPA) syndrome from familial Mediterranean fever?

Differentiating PFAPA (periodic fever, aphthosis, pharyngitis, and adenitis) syndrome from familial Mediterranean fever (FMF) could be challenging in some cases. Galectin-3 is a lectin with regulatory functions in apoptosis and inflammation. We aimed to test whether galectin-3 could be a biomarker for differentiating PFAPA syndrome from FMF. Patients with PFAPA syndrome, FMF, cryopyrin-associated periodic syndrome (CAPS), and streptococcal pharyngitis, and healthy controls were included in this study. Serum galectin-3 levels were measured using enzyme-linked immunosorbent assay. Eighty-seven patients (36 with PFAPA, 39 with FMF, 8 with CAPS, 4 with streptococcal pharyngitis), and 17 healthy controls were included. Blood samples were drawn during attacks from 20 PFAPA and 7 FMF patients and attack-free periods from 22 PFAPA, 35 FMF, and 8 CAPS patients. The median serum galectin-3 level in the PFAPA-attack group (1.025 ng/ml) was significantly lower than the levels in healthy control (2.367 ng/ml), streptococcal pharyngitis (3.021 ng/ml), FMF attack (2.402 ng/ml), and FMF-attack-free groups (2.797 ng/ml) (p = 0.006, 0.03, 0.01, and < 0.001, respectively). PFAPA-attack-free group had lower galectin-3 levels than the FMF-attack-free group (1.794 vs. 2.797 ng/ml, respectively; p = 0.01). Galectin-3 levels did not differ significantly between CAPS and attack-free PFAPA patients (1.439 ng/ml vs. 1.794 ng/ml, respectively; p = 0.63). In our study, for the first time, we defined galectin-3 as a promising biomarker that differs between PFAPA and FMF patients during both disease flares and attack-free periods. Further studies with high number of patients could validate its role as a biomarker.