BACKGROUND: Sepsis typically results in enhanced coagulation system activation and microthrombus formation. Microparticle (MP) production promotes coagulation and enhances pro-coagulation. This study investigated how circulating MP levels and tissue factor-bearing MP (TF+-MP) activity caused coagulation in patients with septic disseminated intravascular coagulation (DIC).
METHODS: Thirty patients with septic DIC and 30 healthy controls were studied from December 2017 to March 2019. Patient blood samples were collected at enrolment (day 1) and on days 3 and 5; DIC scores and Sequential Organ Failure Assessment (SOFA) scores were recorded. TF+-MP activity was measured using TF-dependent factor Xa generation experiments. Circulating MP concentrations were determined by MP capture assay. Clotting factor activity, antithrombin level, soluble thrombomodulin, and serum tissue factor pathway inhibitor (TFPI) concentrations were measured.
RESULTS: Patients with septic DIC had lower circulating MP levels than healthy control patients. Circulating MP levels in patients with septic DIC were positively correlated with DIC scores and negatively correlated with coagulation factors, but TF+-MP activity did not correlate with clotting factor levels and TFPI.
CONCLUSIONS: In patients with septic DIC, circulating MP levels are important in promoting coagulation activation and increasing clotting factor consumption. TF+-MP activity may not be the main form of active TF.

BACKGROUND: Endothelial microparticles (EMPs) are membrane vesicles shed from endothelial cell in response to injury, activation or apoptosis. Kidney transplantation (KTx) is the treatment of choice for patients with end stage kidney disease (ESKD). The aim of this study was to analyze changes in EMP and serum creatinine (SCr) in patients following KTx.
METHODS: Blood was periodically collected from patients before (pre-KTx) and after KTx for two months. EMPs were identified as CD31(+)/CD42b(-) microparticles and quantified by fluorescence-activated cell scanning.
RESULTS: This study included 213 KTx, 14 kidney/pancreas (KPTx) recipients and 60 healthy donors prior to donation. The recipients were divided into 5 groups based on the cause of ESKD. No differences in the quantity of circulating EMP were seen in the pre-KPTx or KTx recipient sera and healthy donor sera. Patients with ESKD secondary to diabetes mellitus, obstructive/inherited kidney disease and autoimmune disease had a decrease in both circulating EMP and SCr by day 60 after KTx.
CONCLUSIONS: Reduction in both circulating EMP and SCr was seen after kidney KTx in patients with selective ESKD.