[Criteria for the differential diagnosis of spondyloarthropathies, by determining serum hyaluronidase activity].

The study was undertaken to evaluate serum hyaluronidase activity in patients with spondyloarthropatgies and to develop criteria for their differential diagnosis. The author's methods for evaluating serum hyaluronidase activity, which were based on that the formation of a clot of ethacridine lactate (rivanol) with hyaluronic acid is in inverse proportion to its depolymerization under the action of hyaluronidase, were used. Enhanced serum hyaluronidase activity was seen in patients with spondyloarthropathies as compared with the control group (p < 0.0010, which was most evident in psoriatic arthritis. With the diagnostic level of hyaluronidase activity of 4 scores or more, the diagnostic sensitivity of the method in the differential diagnosis of psoriatic arthritis and other spondyloarthropathies was 92% and its diagnostic specificity was 86%.