Prolidase Enzyme Activity in Stroke Patients
Condition: Stroke, Ischemic; Prolidase Deficiency
MeSH terms: Stroke; Ischemic Stroke; Prolidase Deficiency
Study type: Observational

Summary: 
      Stroke is a major cerebrovascular disease that causes significant burdens for human health
      and life, including high morbidity, mortality, and disability. Prolidase enzyme activity was
      found in various organs, such as the heart, brain, thymus, kidney, lung, pancreas, and
      spleen, and in plasma, leukocytes, erythrocytes, and dermal fibroblasts. An increase in
      collagen turnover is known to be correlated with increased prolidase enzyme activity. The aim
      of this study was to investigate whether SPA levels in AIS patients can be used as a
      potential diagnostic and prognostic marker. SPA levels were prospectively evaluated in 37
      patients aged between 20 and 85 years who were admitted within 24 hours of the onset of AIS.
      The control group included 37 healthy volunteers of similar age without any disease.
    

Detailed description: 
      Ischemic stroke constitutes about 80-85% of all stroke cases and is caused by the
      interruption of cerebral blood flow due to a blood clot. Because of reactive oxygen species
      (ROS) production and its oxidative metabolite activity, the brain is highly sensitive to
      oxidative stress. This characteristic plays an important role in the pathogenesis of ischemic
      and hemorrhagic brain injuries .Prolidase, which is a cytosolic exopeptidase and a member of
      the matrix metalloproteinase (MMP) family, cleaves iminodipeptides from carboxy-terminal ends
      of proline or hydroxyproline and is actively involved in collagen metabolism. It has been
      shown that brain MMP activity is correlated with nutritive/oxidative stress and increases
      during reperfusion. Furthermore, in stroke patients, elevated serum MMP levels have been
      reported. Biomarkers that predict the outcome and occurrence of ischemic stroke are
      critically important for prevention and treatment .However, serum prolidase activity (SPA)
      has not been previously assessed in acute ischemic stroke (AIS) patients to our knowledge.
      Therefore, in this study, it's aimed to investigate whether SPA levels in AIS patients can be
      used as a potential diagnostic and prognostic marker.In the study, 37 patients aged between
      20 and 85 years who were admitted within 24 hours of the onset of AIS were prospectively
      evaluated. The control group consisted of 37 healthy volunteers of similar age without any
      disease. A comprehensive physical examination was performed consisting of a neurological
      examination, blood biochemistry and blood count tests, electrocardiography, and a
      posterior-anterior chest X-ray for all patients. AIS patients underwent transthoracic
      echocardiography, multi-slice computed tomography (CT), and bilateral carotid-vertebral
      artery Doppler ultrasonography. National Institutes of Health Stroke Scale (NIHSS) scores,
      measured at 24 hours, 48 hours, and 28 days after stroke, were used to determine stroke
      severity.Ischemic stroke subtypes classification was done according to the Trial of Org 10172
      in Acute Stroke Treatment (TOAST) criteria, as cardioembolism, large-artery atherosclerosis,
      small artery occlusion, stroke of other determined cause, or undetermined cause. The
      measurement method for SPA was defined by Myara et al. The optimized method of Özcan et al.
      was used. Prolidase activity was evaluated with a spectrophotometric method, by measuring the
      proline levels. Briefly, 500 μL pre-incubation solution (50 mmol/L Tris hydrochloride buffer
      at power of hydrogen (pH) 7.8, with 1 mmol/L endogenous antioxidant glutathione (GSH), 5
      mmol/L manganese(II) chloride (MnCl2), and 0.1% Triton X-100) and 100 μL serum were mixed;
      this mixture was then pre-incubated for 3 h at 37°C. A 100-μL volume of pre-incubation serum
      was added to 100 μL 144 mmol/L Gly-Pro solution, and this mixture was incubated for 30 min at
      37°C. After the incubation, 1 ml 0.45 mol/L Trichloroacetic acid solution was added quickly
      to the incubation tube, and the incubation reaction was stopped. This mixture was centrifuged
      at 1500 rpm for 5 min, and 500 μL supernatant was removed.
    

Observational model: Case-Control
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        patients WHO were evaluated in the tertiary care clinic
      
Keywords: Stroke; prolidase; prognosis; biomarker