Protein Z serum levels as a risk factor for acute ischemic stroke in patients with systemic lupus erythematosus: a comparison with diabetic cases

Introduction A number of clinical studies that explored the role of protein Z in coronary heart disease, ischemic stroke, and deep vein thrombosis patients have been published. Particularly in ischemic stroke, patients or at least subgroups of patients with low levels (in the convalescent phase of stroke) or high levels (in the acute phase of stroke) of protein Z have been associated with increased risk of stroke. Aim of the work This cross-sectional study aimed to investigate the role of protein Z in patients with systemic lupus erythematosus (SLE) and/or diabetes mellitus (DM) to determine the association between protein Z serum concentration and acute ischemic stroke in these patients. Patients and methods The study was carried out on selected 40 stroke patients divided into 20 patients with SLE and 20 without SLE, who were further divided equally into diabetic and nondiabetic patients. Assessment included demographic data (age, height, weight, and BMI), clinical examination, laboratory investigations including complete blood count, erythrocyte sedimentation rate, HbA1c, lipid profile, protein Z level, MRI-brain, and extracranial carotid duplex ultrasound. Results As regards protein Z levels, it was 4.4 ± 0.6 μg/ml in group I (DM+SLE), 3.0 ± 0.8 μg/ml in group II (SLE + no DM), 2.6 ± 0.8 μg/dl in group III (no SLE, no DM), and 1.1 ± 0.6 μg/dl in group IV (no SLE + DM), which demonstrated a significant difference between the four groups, with the highest protein Z serum level in group I. Conclusion Our study demonstrated an independent association between increasing blood levels of protein Z in SLE rather than in DM patients and an increased risk for ischemic stroke. However, it remains unclear whether elevated protein Z concentrations are a cause or a consequence of ischemic stroke.