Influence of clinical and experimental intra-articular inflammation on neutrophil gelatinase-associated lipocalin concentrations in horses

Abstract

Objective: To investigate neutrophil gelatinase-associated lipocalin (NGAL) concentrations in serum and synovial fluid (SF) from horses with joint inflammation. Study design: Experimental studies and retrospective clinical study. Sample population: Serum and SF samples were available from healthy horses (n = 19), clinical cases, and horses with experimental joint inflammation. Clinical cases included horses with (n = 10) or without (n = 10) septic arthritis. Experimental intra-articular inflammation was induced by lipopolysaccharide (LPS; n = 7, severe inflammation), lidocaine (n = 6, moderate inflammation), or mepivacaine (n = 6, mild inflammation). Methods: Availability of samples was based on approval from the local ethical committee and from the Danish Animal Experiments Inspectorate. Neutrophil gelatinase-associated lipocalin was measured with a previously validated enzyme-linked immunosorbent assay. Repeated-measurements one- and two-way analysis of variance and correlation analysis were used to analyze NGAL concentrations and white blood cell counts (WBC). Results: After injection of LPS or lidocaine, SF NGAL concentrations increased 343- (P =.0035) and 60-fold (P =.0038) relative to baseline, respectively. Serum NGAL also increased in both groups (P