Stored red-blood-cells inhibit platelet function under physiologic flow

Hematologic adverse effects induced by piperacillin-tazobactam: a systematic review of case reports

Background Piperacillin/tazobactam, a semisynthetic antibiotic, is widely used to treat polymicrobial infections. Its hematologic adverse reactions are rare and the severity can be mild to life-threatening. To our knowledge, there has not been a publication reviewing hematologic abnormalities attributable to piperacillin/tazobactam. Aim of the review To evaluate the characteristic, clinical identification, mechanism and treatment of the hematologic toxicity caused by piperacillin/tazobactam. Method A search of Medline and Embase electronic databases was performed for case reports of adverse reactions of hematologic system related to piperacillin/tazobactam from inception to December 2018. Statistical analysis of demographic, clinical features, laboratory Indexes and treatments was performed using Microsoft EXCEL 2007. Results Fifty-nine references were obtained involving 62 patients. The adverse drug reactions were mainly hemolytic anemia (25, 40.3%), thrombocytopenia (23, 37.1%), and neutropenia (12, 19.4%), which might be accompanied by some typical symptoms. Hemolytic anemia or thrombocytopenia was generally believed to be immune-mediated and often appeared within 10 days, and neutropenia was thought to be related to bone marrow suppression and usually occurred 2 weeks after the initiation of piperacillin/tazobactam. Most patients improved or recovered within a week with treatment or not, and fewer high-quality evidence-based treatments were identified. Conclusion Although part of the patients have clinical symptom, the hematologic adverse drug reactions of piperacillin/tazobactam are easily overlooked or misdiagnosed. Take special caution for patients with prolonged piperacillin/tazobactam treatment or specific disease, and prompt recognition and treatment of the adverse drug reactions are essential and can hasten recovery regardless of the type of side reactions.

Platelet adhesion changes during storage studied with a novel method using flow cytometry and protein-coated beads

The aim of the present study was to set up and evaluate a novel method for studies of platelet adhesion and activation in blood and platelet suspensions such as platelet concentrate (PC) samples using protein-coated polystyrene beads and flow cytometry. To demonstrate its usefulness, we studied PCs during storage. PCs were prepared by aphaeresis technique (n = 7). Metabolic variables and platelet function was measured on day 1, 5, 7 and 12 of storage. Spontaneous and TRAP-6-induced adhesion to fibrinogen- and collagen-coated beads was analyzed by flow cytometry. P-selectin and phosphatidyl serine (PS) expression was assessed on platelets bound to beads as well as on non-adherent platelets. Platelet adhesion to fibrinogen beads had increased by day 12 and adhesion to collagen beads at day 7 of storage (p < 0.05). TRAP-6 stimulation significantly increased the platelet adhesion to fibrinogen beads (p < 0.05) as well as the P-selectin and PS exposure on platelets bound to beads (p < 0.01) during the first 7 days of storage, but by day 12, significant changes were no longer induced by TRAP-6 stimulation. We demonstrate that our adhesion assay using protein-coated polystyrene beads can be used to assess the adhesion properties of platelets during storage without the addition of red blood cells. Therefore it may offer a useful tool for future studies of platelet adhesive capacity in transfusion medicine and other settings.