Serum amyloid A as predictive factor in PFAPA syndrome attack.
This study aimed to assess the diagnostic value of serum amyloid A (SAA) levels during attacks of periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome. A retrospective analysis was conducted on the medical records of 51 children diagnosed with PFAPA and 51 control patients. Serum levels of SAA, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and the neutrophil-to-lymphocyte ratio (NLR) were measured. The median SAA levels were significantly higher in the PFAPA group than in controls (p<0.05). ROC analysis revealed that SAA had a sensitivity of 100% and a specificity of 96.1% at a cutoff value of ≥12.43mg/L, outperforming CRP and ESR in diagnostic accuracy. While CRP and ESR had high sensitivities (90.2% and 90%, respectively), their specificities were lower (96% and 58.8%, respectively). Moreover, the high positive predictive value of SAA underscores its potential role as a reliable marker for the differential diagnosis of PFAPA. SAA is a highly sensitive and specific marker for PFAPA attack, showing greater diagnostic accuracy compared to CRP and ESR. These findings suggest that SAA can serve as a valuable biomarker in the differential diagnosis of PFAPA.