Platelet Disorders

Abstract: After vascular injury and exposure of subendothelial matrix proteins to the intravascular space, mediators of hemostasis are triggered and allow for clot formation and restoration of vascular integrity. Platelets are the mediators of primary hemostasis, creating a platelet plug and allowing for initial cessation of bleeding. Platelet disorders, qualitative and quantitative, may result in bleeding signs and symptoms, particularly mucocutaneous bleeding such as epistaxis, bruising, petechiae, and heavy menstrual bleeding. Increasing evidence suggests that platelets have functional capabilities beyond hemostasis, but this review focuses solely on platelet hemostatic properties. Herein, normal platelet function as well as the effects of abnormal function and thrombocytopenia are reviewed.

Maternal extracellular vesicles and platelets promote preeclampsia via inflammasome activation in trophoblasts

Maternal extracellular vesicles and platelets promote preeclampsia via inflammasome activation in trophoblasts

Shrey Kohli, Satish Ranjan, Juliane Hoffmann, Muhammed Kashif, Evelyn A. Daniel, Moh'd Mohanad Al-Dabet, Fabian Bock, Sumra Nazir, Hanna Huebner, Peter R. Mertens, Klaus-Dieter Fischer, Ana C. Zenclussen, Stefan Offermanns, Anat Aharon, Benjamin Brenner, Khurrum Shahzad, Matthias Ruebner and Berend Isermann.

Blood. 2016; 128:2153-2164; doi:10.1182/blood-2016-03-705434

Evaluation and management of acute menorrhagia in women with and without underlying bleeding disorders: consensus from an international expert panel.

James AH, Kouides PA, Abdul-Kadir R, Dietrich JE, Edlund M, Federici AB, et al. Evaluation and management of acute menorrhagia in women with and without underlying bleeding disorders: consensus from an international expert panel. Eur J Obstet Gynecol Reprod Biol. 2011; 158:124-34

Acute menorrhagia is a common gynecological disorder. Prevalence is high among women with inherited bleeding disorders and recent guidance for optimal management is lacking. Following a comprehensive review of the literature, an international expert panel in obstetrics, gynecology and hematology reached consensus on recommendations regarding the management of acute menorrhagia in women without a diagnosed bleeding disorder, as well as in patients with von Willebrand disease, platelet function disorders and other rare hemostatic disorders. The causes and predictors of acute menorrhagia are discussed and special consideration is given for the treatment of women on anticoagulation therapy. This review and accompanying recommendations will provide guidance for healthcare practitioners in the emergency management of acute menorrhagia. 

Thrombocytopenia and disorders of platelet function in pregnancy. Semin Thromb Hemost. 2011 Sep;37(6): 640-52. Epub 2011 Nov 18. Review.

Pregnancy is associated with physiological and pathological changes in platelet numbers and function, which can be of clinical concern because of risks for maternal and fetal or neonatal bleeding. Thrombocytopenia in pregnancy is frequently encountered and may be due to increased platelet turnover and plasma dilution, immune-mediated mechanisms, or a complication of a more severe underlying pregnancy-related disorder such as preeclampsia. Inherited defects in platelet function and number may also manifest during pregnancy with the risk of bleeding dependent on the underlying problem. In some women, the diagnosis of thrombocytopenia will precede pregnancy but in others, the problem is first identified when routine pregnancy blood tests are performed. An accurate diagnosis and risk assessment in the antenatal period are essential for developing specific plans for any antenatal interventions and for management of delivery and the postpartum periods, and the neonate. Management of pregnant women with platelet disorders requires a multidisciplinary approach and close collaboration between the obstetric and hematology teams.