The sFLT-1/PlGF Ratio for the Prediction of Preeclampsia-Related Adverse Fetal and Maternal Outcomes in Women with Preexisting Diabetes.

To evaluate the predictive value of the sFlt-1/PlGF ratio for the prediction of preeclampsia in women with preexisting diabetes mellitus. This is a monocentric retrospective observational study conducted between January 2018 and December 2020. All singleton pregnancies with preexisting diabetes mellitus, who had a dosage of the sFlt-1/PlGF ratio between 30 and 34 + 6 weeks of gestation were included. The principal outcome was preeclampsia. The secondary outcomes were preterm preeclampsia, gestational hypertension, placental abruption, intrauterine fetal death, IUGR, small for gestational age and a composite outcome named "hypertensive disorder of pregnancy" including gestational hypertension, preeclampsia and HELLP syndrome (hemolysis, elevated liver enzymes and low platelet count). Of 63 patients, 22% presented preeclampsia. The area under the curve of sFlt-1/PlGF ratio was 0.90 (95% CI: 0.79-0.96) for the prediction of preeclampsia. The receiver operator characteristic analysis suggested that the optimal sFlt-1/PlGF cutoff to predict preeclampsia was 29, with a sensitivity of 86% (95% CI: 60.1-96.0) and a specificity of 92% (95% CI: 80.8-96.8). A cut-off of 38 provided a sensitivity of 71% (95% CI: 45.4-88.3), a specificity of 92% (95% CI: 80.8-96.8). Further analysis using multivariable methods revealed nephropathy was significantly associated with PE (p = 0.014). The use of the sFlt-1/PlGF ratio during the third trimester of pregnancy seems to be of interest as a prognostic tool to improve multidisciplinary management of patients with preexisting diabetes mellitus.

Effects of Acute Dengue Infection on Sperm and Virus Clearance in Body Fluids of Men.

We investigated the effects of dengue virus (DENV) on semen using samples collected 7, 15, 30, 60, and 90 days after symptom onset from 10 infected volunteers on Réunion Island. We assessed characteristics of semen and reproductive hormones and isolated motile spermatozoa from semen. We assayed semen for DENV using reverse transcription PCR and searched for DENV RNA by virus isolation in Vero E6 cell cultures. Four volunteers had >1 DENV RNA-positive semen samples; 2 volunteers had DENV RNA-positive semen at day 15 and 1 at day 30. No motile sperm were DENV positive. After exposure to positive semen, few Vero E6 cells stained positive for DENV antigens, indicating low levels of replicative virus. We found DENV had shorter duration in semen than in blood. These findings support the possibilities that DENV is sexually transmissible for a short period after acute dengue illness and that acute dengue induces reversible alterations in sperm.

Development of a multivariable prediction model for congenital unilateral absence of the vas deferens in male partners of infertile couples.

BACKGROUND: Congenital unilateral absence of vas deferens has been diagnosed in fertile and normozoospermic males and is associated with the risk of unilateral renal absence or cystic fibrosis transmembrane conductance regulator mutations; but no prediction model currently exists to diagnose this condition. OBJECTIVES: The study aims to identify clinical and biological variables that may have a predictive value for the diagnosis of congenital unilateral absence of vas deferens in male partners of infertile couples MATERIALS AND METHODS: We designed a retrospective, cross-sectional, case-control study on electronic health records of a single tertiary-care andrological centre collected between 1998 and 2018. We included all subjects diagnosed with congenital unilateral absence of vas deferens using combined scrotal and transrectal ultrasounds. Controls were confirmed free of congenital unilateral absence of vas deferens by the same way. Both groups received standardised exploration procedures. Multivariable logistic regression model was built in a backward stepwise manner. Model performance and calibration were assessed. The study is reported according to TRIPOD statement. RESULTS: We included 69 congenital unilateral absence of vas deferens cases and 78 controls. Cases had a lower semen volume than controls. The congenital unilateral absence of vas deferens risk was associated with history of cryptorchidism and both levels of semen fructose and α-glucosidase. These predictors were confirmed by a random forest algorithm. The area under the curve was 0.886 (95% interval: 0.81-0.92). Calibration was performed with the Hosmer-Lemeshow test (p = 0.88). DISCUSSION AND CONCLUSION: History of cryptorchidism, semen fructose and α-glucosidase were identified as relevant and independent predictors for the diagnosis of congenital unilateral absence of vas deferens. The model enables to identify male patients with a high risk of congenital unilateral absence of vas deferens to whom a transrectal ultrasounds would be proposed to confirm the diagnosis, whatever their semen parameters. It will also help to address the risks of unilateral renal absence and of cystic fibrosis transmembrane conductance regulator mutations carrying during the management of infertile couples.

Applying the concept of uncertainty to the sFlt-1/PlGF cut-offs for diagnosis and prognosis of preeclampsia.

OBJECTIVES: Placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) assays and the corresponding ratios (sFlt-1/PlGF) have been proposed to aid in the diagnosis by exclusion and/or prognosis of preeclampsia (PE). A method for evaluating ratio uncertainties (RUs), based on the theory of error propagation, was applied to the sFlt-1/PlGF ratio. METHODS: RUs were calculated using data derived from sFlt-1 and PlGF Internal Quality Control (IQC) results collected from four centers using Elecsys (Roche) or Kryptor (Thermo Fisher) sFlt-1 and PlGF assays. The corresponding ratio uncertainties were defined for each ratio value. RESULTS: The RUs increased linearly with the sFlt-1/PlGF ratio values. The Elecsys RUs were lower than the Kryptor RUs. Although RUs cannot eliminate differences in ratio values observed among various immunoassays, it can affect interpretation of the sFlt-1/PlGF ratio, especially when results are within the range of predefined PE diagnosis or prognosis cut-offs. CONCLUSIONS: Since RUs are only a function of PlGF and sFlt-1 precision, they can be calculated for each assay from each laboratory to adjust the interpretation of sFlt-1/PlGF ratio results in the context of PE.

Evaluation of the Prognostic Value of the sFlt-1/PlGF Ratio in Early-Onset Preeclampsia.

OBJECTIVE: Increased expression of soluble fms-like tyrosine kinase 1 (sFlt-1), associated with a decrease in placental growth factor (PlGF), plays a key role in the pathogenesis of preeclampsia (PE). We evaluated the prognostic value of the sFlt-1/PlGF ratio for the onset of adverse maternofetal outcomes (AMFO) in case of early-onset PE with attempted expectant management. STUDY DESIGN: From October 2016 through November 2018, all singleton pregnancies complicated by early-onset PE (before 34 weeks of gestation) were included in a cohort study. The plasma levels of sFlt-1 and PlGF were blindly measured on admission. For the statistical analysis, we performed a bivariate analysis, a comparison of the receiving operating characteristic curves and a survival analysis estimated by the Kaplan-Meier method. RESULTS: Among 109 early PE, AMFO occurred in 87 pregnancies (79.8%), mainly hemolysis, elevated liver enzymes, and low platelet count syndrome and severe fetal heart rate abnormalities requiring urgent delivery. The area under the curve (AUC) of sFlt-1/PlGF ratio was 0.82 (95% confidence interval [CI]: 0.73-0.88) for the risk of AMFO and the difference between the AUCs was significant for each separate standard parameter (p = 0.018 for initial diastolic blood pressure, p = 0.013 for alanine aminotransferase, p < 0.001 for uric acid). Pregnancies were best classified by a cutoff ratio of 293, with a sensitivity of 95% and a specificity of 50%. With a ratio value less than 293, no pregnancy was complicated or had been stopped during the first 5 days. A ratio more than 293 was associated with an increased risk of AMFO onset (hazard ratio [HR]: 3.61; 95% CI: 2.13-6.10; p < 0.001) and had a significant association with the length of time between the diagnosis of PE and delivery (HR: 2.49; 95% CI: 1.56-3.96; p < 0.001). CONCLUSION: The sFlt-1/PlGF ratio is an additional tool in the prediction of AMFO in proven early-onset PE, which is likely to improve care by anticipating severe complications. KEY POINTS: · The sFlt-1/PlGF ratio is associated with AMFO.. · It is an additional tool for physician.. · We proposed a 293 cutoff value for the ratio..

Genetics of the congenital absence of the vas deferens.

Congenital absence of the vas deferens (CAVD) may have various clinical presentations depending on whether it is bilateral (CBAVD) or unilateral (CUAVD), complete or partial, and associated or not with other abnormalities of the male urogenital tract. CBAVD is usually discovered in adult men either during the systematic assessment of cystic fibrosis or other CFTR-related conditions, or during the exploration of isolated infertility with obstructive azoospermia. The prevalence of CAVDs in men is reported to be approximately 0.1%. However, this figure is probably underestimated, because unilateral forms of CAVD in asymptomatic fertile men are not usually diagnosed. The diagnosis of CAVDs is based on clinical, ultrasound, and sperm examinations. The majority of subjects with CAVD carry at least one cystic fibrosis-causing mutation that warrants CFTR testing and in case of a positive result, genetic counseling prior to conception. Approximately 2% of the cases of CAVD are hemizygous for a loss-of-function mutation in the ADGRG2 gene that may cause a familial form of X-linked infertility. However, despite this recent finding, 10-20% of CBAVDs and 60-70% of CUAVDs remain without a genetic diagnosis. An important proportion of these unexplained CAVDs coexist with a solitary kidney suggesting an early organogenesis disorder (Wolffian duct), unlike CAVDs related to CFTR or ADGRG2 mutations, which might be the result of progressive degeneration that begins later in fetal life and probably continues after birth. How the dysfunction of CFTR, ADGRG2, or other genes such as SLC29A3 leads to this involution is the subject of various pathophysiological hypotheses that are discussed in this review.

External quality assessment program for biochemical assays of human seminal plasma: a French 6-years experience.

BACKGROUND: In 1999, despite a longstanding use, the WHO manual for the examination of human semen finally proposed to assay several biochemical components of the seminal plasma for a functional exploration of the male accessory glands. At the same time, an international effort was made to standardize laboratory tests and to increase their performance through ISO 15189 accreditation. In this setting, participation to relevant external quality assessment (EQA) schemes is an essential requirement for laboratories. To fulfil this injunction, we have organized an EQA program for seminal biochemistry using presumed commutable samples. In this study, we aimed to report an overview of the French laboratory offer, the kinds of assays used, their performance as well as their likelihood of satisfying ISO15189 requirements for EQA. RESULTS: Between 2014 and 2019, we performed seven surveys. A median of six laboratories participated to each survey giving a ratio of one laboratory per 11.2 million inhabitants. Seven biomarkers are routinely assayed but the core set shared by all laboratories comprised citrate and zinc (prostate), fructose (seminal vesicles) and α-1, 4 glucosidase (epididymis). The use of CE-IVD marked methods concerned between 0 to 75% of overall assays. According to analytical specifications, 100% of laboratories results were compliant for zinc, 75% for citrate and α-1,4 glucosidase and 67% for fructose. By combining overall data in an empirical scoring system, we identified several types of seminal biomarkers: citrate, fructose and zinc appear as good candidates for a full accreditation, α-1,4 glucosidase still presents an analytical weakness, but prostatic acid phosphatase, free L-carnitine and glycerophosphocholine cannot be accredited in the current state. CONCLUSIONS: We organized the first French EQA program for seminal biochemistry to help local laboratories to face their legal requirement to be fully accredited by 2020. It could be improved still further but it gave us an oversight on the analytic landscape. Effective methods are available for a confident biochemical exploration of prostate and seminal vesicles. However, that of epididymis appeared unexpectedly fragile. This andrological issue should be addressed by dedicated recommendations from health authorities and scientific societies.

Aspirin for prevention of preeclampsia and fetal growth restriction.

For the past decades, growing attention has been given to aspirin use during pregnancy. It favors placentation by its proangiogenic, antithrombotic, and anti-inflammatory effects. Therefore, low doses of aspirin are prescribed in the prevention of placenta-mediated complications, mainly preeclampsia and fetal growth restriction. However, questions regarding its clinical application are still debated. Aspirin is effective in preventing preeclampsia in a high-risk population. Most guidelines recommend that risk stratification should rely on medical history. Nevertheless, screening performances dramatically improve if biochemical and biophysical markers are included. Concerning the appropriate timing and dose, latest studies suggest aspirin should be started before 16 weeks of pregnancy and at a daily dose of 100 mg or more. Further studies are needed to improve the identification of patients likely to benefit from prophylactic aspirin. Besides, the role of aspirin in the prevention of fetal growth restriction is still questioned.

Male partners of infertile couples with congenital unilateral absence of the vas deferens are mainly non-azoospermic.

BACKGROUND: Men with congenital unilateral absence of vas deferens were reported to be mainly azoospermic, with both unilateral renal absence and mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) but some have neither. OBJECTIVES: To assess whether in infertile couples the male partners with congenital unilateral absence of vas deferens are mainly azoospermic men. MATERIAL AND METHODS: Retrospective study in a unique university hospital; reproductive, clinical, CFTR analysis and seminal data of male partners of infertile couples (from 1998 to 2018) were analysed. Diagnosis of congenital unilateral absence of vas deferens was based on transrectal ultrasounds (TRUS): complete or partial absence of one vas deferens with complete contralateral vas deferens confirmed in 63 men. Distribution of sperm count in three classes: azoospermia, oligozoospermia or normozoospermia. Ultrasound determination of renal status; seminal biomarkers assays; and search for CFTR mutations. RESULTS: Among the 63 men, 39.7% displayed azoospermia, 27% oligozoospermia and 33.3% normozoospermia; 42% of the non-azoospermic men (16/38) had previously obtained a natural pregnancy. We found unilateral renal absence in 17/59 patients (29%). Among 50 men with CFTR testing, five carried an allele associated with cystic fibrosis belonging to the 29 men without renal anomalies, indicating a high allelic frequency (8.6%). The 63 patients displayed high rates of surgical histories for undescended testicles or inguinal hernia, low values of semen volume and of total seminal glycerophosphocholine. CONCLUSIONS: Our results indicate that men with congenital unilateral absence of vas deferens mainly display oligozoospermia or normozoospermia and that they were previously fertile. They clearly confirm, first, that CFTR testing is recommended in congenital unilateral absence of vas deferens men and it should be mandatory for those with normal kidneys; and, second, that TRUS is needed for the diagnosis of congenital unilateral absence of vas deferens. As congenital unilateral absence of vas deferens may be present whatever the sperm count, biological warnings are represented by semen volume and seminal epididymal markers and clinical warnings by surgical histories of undescended testes or inguinal hernia.

Experimental mild increase in testicular temperature has drastic, but reversible, effect on sperm aneuploidy in men: A pilot study.

In mammals testicular and epididymal temperature increase impairs spermatogenesis. This experimental study investigates the effects of a mild testis temperature increase (i.e. testis temperature remains below core body temperature) on sperm aneuploidy in men. In 5 fertile volunteers a testicular temperature increase was induced by maintaining the testes at suprascrotal position using specially designed underwear for 15 ±â€¯1 h daily for 120 consecutive days. After heating men were followed for next 180 days. A control group (27 men) was recruited. Semen samples were collected before, during and after heating period and analyzed for chromosomes X, Y and 18 for aneuploidy using FISH. A total of 234,038 spermatozoa were studied by FISH. At day 34 of heating, mean sperm aneuploidy values were not modified. From day 34 of heating until day 45 post heating, FISH evaluation was not possible due to the drastic fall of sperm count. At day 45 post-heating total sperm aneuploidy percentage was twice higher than before heating whereas. Sex disomy (sperm XY18), sex chromosome nullisomy (sperm 18) were significantly higher than controls. These effects were completely reversed at 180 days post heat exposure. Conclusion: A mild rise in testicular temperature significantly increases sperm aneuploidies, reflecting an effect on the meiosis stage of spermatogenesis. The effect of heating was reversible and suggests that recovery of aneuploidy to normal values requires at least two cycles of spermatogenesis. Nonetheless, the low number of volunteers was a limitation of this pilot study and warrants further research on larger population.

Mild experimental increase in testis and epididymis temperature in men: effects on sperm morphology according to spermatogenesis stages.

BACKGROUND: A mild increase in testicular and epididymal temperatures in men, bulls and rams (pendulous scrotum) inhibits spermatogenesis and increases the percentage of sperm with an abnormal morphology. However, the stages of spermatogenesis that are most sensitive to a mild increase in testicular temperature in men are unknown. The aim of the present study was to explore the effects of a mild induced increase in testicular and epididymal temperature (i.e., testicular temperature maintained below the core body temperature) on sperm morphology in humans depending on the physiological time of spermatogenesis and epididymal transit. METHODS: Five healthy volunteers were enrolled in an experimental study in which testicular and epididymal temperatures were increased by maintaining the testes in a supra-scrotal position with a specially designed underwear worn 15±1 h a day for 120 consecutive days. Semen collection was scheduled on specific days depending on spermatogenic stages and epididymal transit. RESULTS: Sperm morphology and the multiple anomalies index (MAI) were analysed before, during and after heating. This mild induced increase in testicular and epididymal temperatures resulted in a significant rise in the percentage of morphologically abnormal spermatozoa on day 34 of heating, which remained elevated throughout the heating period and persisted until 45 days after cessation of heating. The MAI was significantly increased on day 20 throughout the heating period and persisted 45 days after cessation of heating. An increase in the percentage of anomalies in the sperm head, acrosome or tail occurred on days 34 and/or 45 of heating. Abnormal sperm morphology and MAI reverted to control values 73 days after cessation of heating. CONCLUSIONS: A mild sustained increase in testicular and epididymal temperature in man leads morphological abnormalities in spermatozoa mainly due to an impairment of spermiogenesis and meiosis.

Noonan syndrome males display Sertoli cell-specific primary testicular insufficiency.

Context Abnormalities in the hypothalamo-pituitary-gonadal axis have long been reported in Noonan syndrome (NS) males with only few data available in prepubertal children. Objective The aim of this study was to describe the gonadal function of NS males from childhood to adulthood. Design It is a retrospective chart review. Patients and methods A total of 37 males with a genetically confirmed diagnosis of NS were included. Clinical and genetic features, as well as serum hormone levels (LH, FSH, testosterone, anti-Müllerian hormone (AMH), and inhibin B) were analysed. Results Of the 37 patients, 16 (43%) children had entered puberty at a median age of 13.5 years (range: 11.4-15.0 years); age at pubertal onset was negatively correlated with BMI SDS (r = -0.541; P = 0.022). In pubertal boys, testosterone levels were normal suggesting a normal Leydig cell function. In contrast, NS patients had significant lower levels of AMH (mean SDS: -0.6 ± 1.1; P = 0.003) and inhibin B (mean SDS: -1.1 ± 1.2; P < 0.001) compared with the general population, suggesting a Sertoli cell dysfunction. Lower AMH and inhibin B levels were found in NS-PTPN11 patients, whereas these markers did not differ from healthy children in SOS1 patients. No difference was found between cryptorchid and non-cryptorchid patients for AMH and inhibin B levels (P = 0.43 and 0.62 respectively). Four NS-PTPN11 patients had a severe primary hypogonadism with azoospermia/cryptozoospermia. Conclusions NS males display Sertoli cell-specific primary testicular insufficiency, whereas Leydig cell function seems to be unaffected.

Effect of acute Zika virus infection on sperm and virus clearance in body fluids: a prospective observational study.

BACKGROUND: Evidence of human sexual transmission during Zika virus emergence is a matter of concern, particularly in procreation, but to date, kinetics of seminal shedding and the effects of infection on human reproductive function have not been described. To investigate the effects of Zika virus infection on semen and clearance of Zika virus from semen and body fluids, we aimed to study a cohort of Zika virus-infected men. METHODS: This prospective observational study recruited men presenting with acute Zika virus infection at Pointe-à-Pitre University Hospital in Guadeloupe, French Caribbean, where a Zika virus outbreak occurred between April and November, 2016. Blood, urine, and semen were collected at days 7, 11, 20, 30, 60, 90, and 120 after symptom onset, and semen characteristics, such as total sperm count, sperm motility, vitality, and morphology, and reproductive hormone concentrations, such as testosterone, inhibin, follicle-stimulating hormone, and luteinising hormone, were assessed. At days 7, 11, and 20, semen was processed to isolate motile spermatozoa. Zika virus RNA was detected by RT-PCR using whole blood, serum, urine, seminal plasma, semen cells, and motile spermatozoa fractions. Zika virus was isolated from different sperm fractions on Vero E6 cultures. FINDINGS: 15 male volunteers (mean age 35 years [SD 5; range 25-44) with acute Zika virus infection and positive Zika virus RNA detection in blood or urine were enrolled. Total sperm count was decreased from median 119 × 106 spermatozoa (IQR 22-234) at day 7 to 45·2 × 106 (16·5-89·6) at day 30 and 70 × 106 (28·5-81·4) at day 60, respectively, after Zika virus infection. Inhibin values increased from 93·5 pg/mL (IQR 55-162) at day 7 to 150 pg/mL (78-209) at day 120 when total sperm count recovered. In motile spermatozoa obtained after density gradient separation, Zika virus RNA was found in three of 14 patients at day 7, four of 15 at day 11, and four of 15 at day 20, and replication-competent virus was found in the tested patient. Seminal shedding kinetics seemed heterogeneous among patients. Whole blood was the fluid most frequently positive for Zika virus RNA (62 of 92 samples) and three patients remained positive at day 120. INTERPRETATION: Semen alterations early after acute Zika virus infection might affect fertility and could be explained by virus effects on the testis and epididymis. Frequency of shedding and high viral load in semen, together with the presence of replicative virus in a motile spermatozoa fraction, can lead to Zika virus transmission during sexual contact and assisted reproduction procedures. Whole blood seems to be the best specimen for Zika virus RNA detection, diagnosis, and follow-up. FUNDING: Agence de la Biomédecine/Agence Régionale de Santé de la Guadeloupe/Inserm-REACTing.

Diagnosis of Partial Retrograde Ejaculation in Non-Azoospermic Infertile Men with Low Semen Volume.

In non-azoospermic patients with low semen volume (LSV), looking for partial retrograde ejaculation (PRE) by searching sperm in the postejaculatory urine (PEU) is required. The use of a retro-ejaculatory index (R-ratio) was suggested to define PRE, but none of the studies indicated a specific threshold above which PRE must be considered. Our objective was to propose a threshold value for the R-ratio as indicative of PRE in patients with LSV selected to be devoid of any known causes or risk factors for retrograde ejaculation or LSV. Among our data base (2000-2009) including 632 patients with PEU, 245 male patients from infertile couples who had had a first semen analysis with LSV (< 2mL) and a second semen analysis associated with PEU, were selected on the previous criteria. A prospective control group was randomly constituted (2007-2008) of 162 first consulting male patients from infertile couples, with a normal semen volume (≥ 2mL) on a first semen analysis and who accepted to collect PEU with their usual second semen analysis, selected on the previous criteria. To define an R-ratio threshold indicative of PRE, we used a ROC curve analysis and a regression tree based on a classification and regression tree (CART) algorithm. Of the 245 LSV patients, 146 still presented low semen volume (< 2 mL) on the second semen analysis. From the use of the CART algorithm, two low (1.5% and 2.8%) and two high R-values (7.1% and 8.3%) were defined, according to the lower reference limit for semen volume of 2.0 mL (WHO 1999) or 1.5 mL (WHO 2010) respectively. As only one or no patient with normal semen volume was observed above the two high R-values, we suggest an R-value higher than the range of [7.1-8.3]% as indicative of PRE until confirmation by a prospective multicenter study.

Platelet Adhesion and Thrombus Formation in Whole Blood at Arterial Shear Rate at the End of Pregnancy.

PROBLEM: Platelet reactivity has not been evaluated in integrated functional testing during normal pregnancy. Here, we analysed platelet functions under arterial shear rate in comparison with static conditions. METHOD OF STUDY: Thirty pregnant women with uncomplicated pregnancies and 30 healthy non-pregnant women were enrolled in this study. Platelet adhesion to collagen and fibrinogen and subsequent thrombus formation were measured at arterial shear rate in whole blood using a microfluidic and imaging system. Standard light transmission aggregometry, flow cytometry of activation markers in washed platelets and impedance aggregometry in whole blood were also used to assess platelet responsiveness in static conditions. RESULTS: Compared to non-pregnant controls, thrombus formation on collagen fibres and firm platelet adhesion on fibrinogen under arterial shear rate were significantly reduced in pregnant women. Platelet aggregometry assays in suspension showed a slight increase in platelet reactivity in pregnant women. CONCLUSION: While platelet aggregometry and platelet activation markers in static conditions show little changes in platelet reactivity, monitoring of platelet adhesion and thrombus growth on collagen or fibrinogen under flow condition in whole blood indicates a significant decrease in pregnant women compared to controls. This decrease might contribute to counteract a hypercoagulable state and to reduce the risk of arterial thrombosis.