The diagnostic value of Paraoxonase (PON 1) enzyme activity in the diagnosis of knee joint osteoarthritis: case control study

Abstract

Background: Osteoarthritis is one of the most common joint disorders worldwide and it is responsible for significant morbidity and
deterioration of quality of life and in particular elderly population (Mora et al., 2018). The diagnosis is based on clinical as well as
radiological assessment; however, biochemical investigation plays a little role in the diagnosis, but recent data had suggested a role for some biochemical markers in the pathogenesis as well as in the diagnosis and assessment of disease severity.
Aim of the study: the aim of the present study was to evaluate the potential diagnostic role of Paraoxonase (PON 1) enzyme activity in the diagnosis of knee joint osteoarthritis in a sample of Iraqi patients in addition to expolration of role of ESR and CRP with this regard.
Patients and methods: This study is done in outpatient consultation clinic of Rhem& medical rehabilitation at Al-Imamain Al-kadhimain
teaching hospital, Baghdad - Iraq. A case control study was included two groups, knee osteoarthritis group of patients and the control group. It was executed during the term from first of June 2021 to last of December 2021. Determination of Paraoxonase (PON 1) enzyme activity was assessed by Fluorometric method.
Results: Paraoxonase (PON 1) enzyme activity was signficantly lower in patients group in comparison with control group (p < 0.001). Based on these observations, the diagnostic potential of this marker was assessed using receiver operator characteristic (ROC) curve analysis in order to find the best cutoff value of the marker that can predict a diagnosis of osteoarthritis in terms of sensitivity and specificity. The cutoff value of PON-1 was ≤ 0.879 with 86 % sensitivity, 60.7 % specificity and 78.2 % accuracy. The correlation was positive in that the severity of disease get increased with increasing body mass index and it was significant (r = 0.303; p = 0.033).
Conclusion: The severity of disease is more with higher body mass index a finding that further solidify that suggestion. Higher levels of
ESR and CRP in patients with knee joint osteoarthritis are indicators of the role of inflammation in the initiation and progression of such joint disorder. Low level of Paraoxonase (PON 1) enzyme activity in patients with knee OA suggest adiagnostic potnetial but with poor accuarcy.