During pregnancy, numbers of MP initially decrease and subsequently normalize. Placenta-derived MP increase, possibly because of placental growth. In preeclampsia, reduced numbers of PMP are due to decreased platelet counts. Increased numbers of monocyte-derived MP reflect monocyte activation, which may be an expression of the systemic inflammation in preeclampsia. Lack of correlation between numbers of MP and severity of preeclampsia suggests that MP numbers alone do not explain the reported vascular effects of MP.

Platelet activation in preeclampsia is reflected by elevated levels of platelets exposing P-selectin. In plasma, a non-cell bound (soluble) form of P-selectin is present. Elevated levels of this soluble form have been reported in preeclampsia. Plasma P-selectin may consist of two fractions: microparticle (MP)--associated P-selectin and non-MP--associated P-selectin. In the present cross-sectional study, we investigated to which extent plasma P-selectin is MP--associated and whether such MP are elevated in preeclamptic patients. Preeclamptic patients (n=10) were matched with normotensive pregnant women (n=10) and non-pregnant controls (n=10). Plasma P-selectin was measured by ELISA. MP were isolated, double labelled with anti-CD61 (GPIIIa) and anti-CD62P (P-selectin) and subsequently analyzed with flowcytometry. Plasma P-selectin concentration was elevated in preeclamptic patients compared to non-pregnant controls (p=0.007), but not compared to normotensive pregnant women (p=0.210). Plasma P-selectin is partially MP--associated (3-5%). In pregnancy, the fraction of P-selectin exposing platelet-derived MP (PMP) (10.9%) was increased compared to non-pregnant controls (8%). This fraction further increased in preeclamptic patients (15.4%), and significantly differed from normotensive pregnant women (p=0.02). A minor fraction of plasma P-selectin is associated with PMP. The fraction of PMP exposing P-selectin is increased in preeclamptic patients and to a lesser extent in normotensive pregnancy. Because MP associated P-selectin exclusively originates from platelets, this fraction indicates platelet activation. Platelet activation is prominent in preeclampsia and this study proves that at least a part of the plasma P-selectin originates from platelets.

The extent of surgery and the decision for adjuvant treatment in patients with endometrial cancer (EC) depend on the presence of risk factors for lymph node metastases and disease recurrence. Postoperative markers such as myometrial infiltration and specific mutations can select patients for adjuvant treatment but will not influence surgical planning. A biomarker stratifying patients into low-risk and high-risk groups before surgery could identify patients who benefit from more extensive surgery. Therefore, we evaluated the correlation of serum biomarker HE4 with clinical and recently identified prognostic pathological variables and survival. Patients treated for endometrial cancer between 1994 and 2014 were included. Serum HE4 concentration was measured in preoperatively obtained samples. A total of 88 patients were eligible for analysis. The majority (64%) was diagnosed with endometrioid-type adenocarcinoma. Serum HE4 concentration is significantly associated with stage of disease (p = 0.001), deep myometrial invasion (p < 0.001), exact depth of myometrial invasion (≥4 mm) (p = 0.01), tumour-free distance to serosa (≤7 mm) (p < 0.001), extensive lymph vascular space invasion (p = 0.04) and cervical involvement (p = 0.001). HE4 concentration and nodal involvement were correlated, although not significant (p = 0.17). Serum HE4 is an independent prognostic factor for recurrence-free survival (HR 5.12 per 10-fold increase in HE4, 95% CI 1.54-17.1) and overall survival (HR 7.48 per 10-fold increase in HE4, 95% CI 1.76-31.7). HE4 is a prognostic marker in endometrial cancer and is helpful in addition to other variables for the preoperative risk stratification of patients with endometrial cancer.

Full-length Flt-1 is associated with platelet and placenta-derived microparticles. Possibly, the presentation of Flt-1 on the membrane of a microparticle might alter its function, particularly if it acts in synergism with other exposed vasoactive molecules.