No correlation between mean platelet volume and carotid artery thickness in patients with diabetes at intermediate or high risk for cardiovascular diseases.

The number of patients with diabetes with a risk of cardiovascular diseases (CVDs) is increasing worldwide, leading to a higher demand for evaluating atherosclerosis. Recently, the mean platelet volume (MPV) available from complete blood count is gaining attention as a marker of underlying atherosclerotic lesions. In the current study, we examined whether MPV can predict carotid atherosclerosis in patients with diabetes at an intermediate or high risk for CVD. A total of 224 patients with diabetes aged 36-85 years who underwent carotid ultrasound examination were assessed. The risk of CVD was evaluated using the Suita score. The greatest carotid intima-media thickness (IMT) in each common carotid artery (CCA Max-IMT), carotid bulb, internal carotid artery, or external carotid artery (Total Max-IMT) was measured. Subsequently, the relationship between MPV and IMT was analyzed. Patients were divided into three groups according to their MPV values (<9.5 fl, tertile 1; 9.5-10.2 fl, tertile 2; and >10.2 fl, tertile 3). A correlation was observed between MPV and platelet count (P < 0.001), platelet distribution width (P < 0.001), and glycated hemoglobin (P = 0.04); however, multivariate logistic regression analyses demonstrated no relationship between MPV and CCA Max-IMT [odds ratio, 0.89 (0.60-1.29), P = 0.54] or Total Max-IMT [odds ratio, 0.87 (0.61-1.24), P = 0.45]. MPV did not correlate with carotid artery thickness. Therefore, it is difficult to determine the significance of MPV in atherosclerotic conditions from this study.

Prolonged Activated Partial Thromboplastin Time and False-Positive Results for Fibrinogen and Fibrin Degradation Products in a B-Cell Lymphoma Patient.

We report a unique case of a B-cell lymphoma patient in whom IgM monoclonal gammopathy resulted in a prolonged activated partial thromboplastin time (APTT) and false-positive results for fibrinogen and fibrin degradation products (FDPs). An 86-year-old man was referred to our hospital for further examination of abnormal cells in his peripheral blood. Laboratory data upon admission revealed an elevation of monoclonal IgM, presence of FDPs and marked prolongation of APTT (>180 s). Bone marrow examination revealed a predominant involvement of B lymphoma cells. In vitro examination revealed that IgM isolated from the patient's plasma had resulted in false-positive results for FDPs and APTT. Neither hemorrhagic nor thrombotic tendency was observed in this patient, suggesting that the abnormal coagulation data were due to interference by elevated monoclonal IgM levels.