Background Early arthritis (EA) is one of the most important problems of modern rheumatology. Searching the new pathogenic mechanism of recently-onset joints inflammation caused by different factors is needed. Enzymatic serum activity is multifactorial system, which play major role in inflammation processes in rheumatic diseases. The aim of our study was to study the levels of nuclease (DNAse) and hyaluronidase activity in patients with EA and to evaluate their pathogenic and diagnostic significance.
Objectives We studied 190 persons: 64 patients with early rheumatoid arthritis (ERA) (disease duration 4.23±2.21 months), 55 patients with acute reactive arthritis (AReA), associated with Chlamydia trachomatis urogenital infection(disease duration 3.15±2.11 months), 36 patients with unclassified arthritis (UA) (disease duration 3.32±2.14 months) and 40 healthy controls from the same regional area in Belarus.
Methods The samples of patients and healthy persons sera were investigated. DNAse serum activity was determined by rivanol clot prevention test and agarose electrophoresis. Hyaluronidase serum activity was determined by rivanol clot prevention test. Statistical data differences for means and medians were assessed by the Student’s t-test and Mann-Whitney’s U-test, respectively. Statistical correlations were calculated by the Spearman method.
Results The levels of DNAse serum activity in patients with EA - ERA (Me 4.50 units, 95%CI 4.00-5.00), AReA (Me 3.00 units 95%CI 2.92-3.00), UA (Me 3.00 units, 95%CI 2.00-4.00) were higher (p<0.01) than in controls (Me 1.00 units, 95%CI 1.00-2.00). The levels of DNAse serum activity in ERA were higher (p<0.05) than in AReA and UA.
The levels hyaluronidase serum activity in patients with EA - ERA (Me 4.00 units, 95%CI 4.00-4.00), AReA (Me 3.00 units 95%CI 3.00-3.00), UA (Me 3.00 units, 95%CI 2.84-4.00) were higher (p<0.01) than in controls (Me 1.00 units, 95%CI 0.52-2.00). The levels of hyaloronidase serum activity in patients with ERA were substantially (p<0.05) higher than in patients with AReA and UA.
We obtained the correlation between DNAse serum activity and swollen joints numbers (r=0.30), ESR (r=0.53) in ERA, swollen joints numbers (r=0.74), ESR (r=0.27), immune complexes numbers (r=0.30) in AReA, disease duration (r=0.40), B-cells numbers (r=-0.44) in UA, p<0.05 respectively.
We revealed that determination serum DNAse activity elevated levels (3 and more units) might be applied for discrimination of ERA from AReA and UA (sensitivity 79.69% (95%CI: 67.80-88.70), specificity 80.22% (95%CI: 70.60-87.80), PLR 4.03, NLR 0.25). The detection of hyaluronidase activity elevated levels (3 and more units) might be implicated for discrimination of ERA from AReA and UA (sensitivity 85.94% (95%CI: 75.00-93.30), specificity 79.12% (95%CI: 69.30-86.90), PLR 4.12, NLR 0.18).
Conclusions For the first time we confirmed the presence of elevated levels of serum DNAse and hyaluronidase activity in patients with EA in comparison with the healthy persons and prevalence of these activities in ERA. The established interrelationships between DNAse activity and clinical and laboratory manifestations of EA can pose pathogenic significance. We proposed original tests for differentiation of ERA from AReA and UA on the basis of assessment of DNAse and hyaluronidase serum activities.
Disclosure of Interest None Declared