Serum amyloid A a valuable biomarker in acute anterior uveitis

Patients with acute anterior uveitis (AAU) see elevated levels of serum amyloid A (SAA), which may help in monitoring inflammatory processes and assess the efficacy of therapies, a recent study has found.

Researchers enrolled 108 AAU patients (median age, 41.5 years; 59 males), from whom blood samples were collected and subjected to immunochromatography analysis, for the measurement of biomarkers. A parallel group of 18 healthy controls (mean age, 29.5±8.3 years; 11 males) was included.

Median SAA concentrations were significantly lower in healthy controls than in AAU patients (0 vs 3.83 mg/L; p<0.0001). Stratifying AAU patients according to the presence of human leukocyte antigen-B27 (HLA-B27) showed that patients positive for the marker had significantly higher median SAA levels (4.19 vs 2.83 mg/L; p=0.014).

A similar discrepancy was reported when categorizing patients according to ankylosing spondylitis (AS). SAA was significantly higher in those with vs without AS (4.31 vs 3.51 mg/L; p=0.024). SAA was also elevated in patients with active vs inactive AAU (5.42 vs 2.81 mg/L; p<0.0001).

SAA levels also showed strong predictive value for the active inflammation of AAU. At a cutoff value of 3.22 mg/L, the area under the receiver operating curve was 0.727, with sensitivity and specificity values of 77.2 percent and 60.8 percent, respectively.

Twelve patients were followed to assess the effect of treatment. SAA level dropped significantly after intervention (10.9 to 3.61 mg/L; p=0.0002), coinciding with the improvement of AAU inflammation.