Use of autologous platelet-rich clots for the prevention of local injury bleeding in patients with severe inherited mucocutaneous bleeding disorders

Standardized Platelet-Rich Fibrin (PRF) from canine and feline origin: An analysis on its secretome pattern and architectural structure

Platelet-rich fibrin (PRF) has been incorporated in surgical procedures to promote tissue and bone healing, particularly in human medicine. The rationale for the use of platelet-based products stems from the fact that platelets, after being activated, release growth factors (GFs) and other active molecules such as cytokines, that modulate inflammation and tissue repair. Although PRF has been advanced as a therapeutic treatment for veterinary use, namely in canine and feline patients (following human medicine developments), to our knowledge a full characterization of PRF therapeutic effectors has never been performed. Herein, we studied the biological properties and release profile of GFs and other cytokines throughout ten days in in vitro culture conditions, in order to investigate the potential therapeutic ability of PRF for canine and feline practice. A protocol for obtaining PRF from whole blood without anti-coagulant from both species was optimized, originating large and homogenous PRF clots. Then, PRF clots obtained from four dogs and four cats were incubated in culture medium to assess the temporal release of platelet-derived growth factor-BB (PDGF-BB), vascular endothelial factor-A (VEGF-A), transforming growth factor β-1 (TGF-β1), and interleukin-8 (IL-8). Furthermore, morphological characterization of PRF clots, fresh and after 10 days of incubation, was performed by histology and high-resolution field emission electron scanning microscopy. In standard culture conditions, PRF clots from both species released PDGF-BB, TGF- β1 and VEGF-A, in a sustained manner, up to day 10. Moreover, PRF presents an initial burst release of IL-8, a mediator of inflammatory response which plays a key role in neutrophil recruitment and degranulation. Overall, our findings show that PRF clots may be an efficient therapeutic strategy in canine and feline clinical practice, accelerating the local healing mechanism, through the sustained delivery of signalling molecules involved in the healing cascade.

World Workshop on Oral Medicine VII: Bleeding control interventions for invasive dental procedures in patients with inherited functional platelet disorders: A systematic review

OBJECTIVES

The objective of this study was to determine bleeding control interventions (BCIs) that were reported to be effective in controlling postoperative bleeding in patients with inherited functional platelet disorders (IFPDs) undergoing invasive dental procedures.

STUDY DESIGN

We searched MEDLINE/PubMed, Embase, Cochrane Library (Wiley), and Scopus from 1960 through April 2020 for studies on patients with IFPD undergoing invasive dental procedures. Two reviewers conducted assessments independently.

RESULTS

We found a total of 620 nonduplicate published articles, of which 32 studies met our inclusion criteria. Management with BCI in patients with IFPD included in this systematic review was effective in 80.7% of treatment sessions. Local measures used intraoperatively were found to be effective. Three different protocols of BCI were noted; the most effective protocol consisted of antifibrinolytics, scaffold/matrix agents, and sutures (P < .01). An adjunct protocol consisting of a tissue sealant was also effective (P < .01). A third protocol of platelet transfusion and antifibrinolytics was ineffective in controlling postoperative bleeding in 4 of 6 dental sessions.

CONCLUSIONS

This systematic review supports the use of local measures intraoperatively and antifibrinolytics postoperatively. It also supports making decision regarding platelet transfusion based on the clinician's clinical judgment and medical history of the individual patient.

Learning the Ropes of Platelet Count Regulation: Inherited Thrombocytopenias

Inherited thrombocytopenias (IT) are a group of hereditary disorders characterized by a reduced platelet count sometimes associated with abnormal platelet function, which can lead to bleeding but also to syndromic manifestations and predispositions to other disorders. Currently at least 41 disorders caused by mutations in 42 different genes have been described. The pathogenic mechanisms of many forms of IT have been identified as well as the gene variants implicated in megakaryocyte maturation or platelet formation and clearance, while for several of them the pathogenic mechanism is still unknown. A range of therapeutic approaches are now available to improve survival and quality of life of patients with IT; it is thus important to recognize an IT and establish a precise diagnosis. ITs may be difficult to diagnose and an initial accurate clinical evaluation is mandatory. A combination of clinical and traditional laboratory approaches together with advanced sequencing techniques provide the highest rate of diagnostic success. Despite advancement in the diagnosis of IT, around 50% of patients still do not receive a diagnosis, therefore further research in the field of ITs is warranted to further improve patient care.

Current and Emerging Options for the Management of Inherited von Willebrand Disease

Von Willebrand disease (VWD) is the most common inherited bleeding disorder with an estimated prevalence of ~1% and clinically relevant bleeding symptoms in approximately 1:10,000 individuals. VWD is caused by a deficiency and/or defect of von Willebrand factor (VWF). The most common symptoms are mucocutaneous bleeding, hematomas, and bleeding after trauma or surgery. For decades, treatment to prevent or treat bleeding has consisted of desmopressin in milder cases and of replacement therapy with plasma-derived concentrates containing VWF and Factor VIII (FVIII) in more severe cases. Both are usually combined with supportive therapy, e.g. antifibrinolytic agents, and maximal hemostatic measures. Several developments such as the first recombinant VWF concentrate, which has been recently licensed for VWD, will make a more "personalized" approach to VWD management possible. As research on new treatment strategies for established therapies, such as population pharmacokinetic-guided dosing of clotting factor concentrates, and novel treatment modalities such as aptamers and gene therapy are ongoing, it is likely that the horizon to tailor therapy to the individual patients' needs will be extended, thus, further improving the already high standard of care in VWD in most high-resource countries.

Inherited platelet function disorders. Diagnostic approach and management

Inherited platelet function disorders (IPFDs) make up a significant proportion of congenital bleeding diatheses, but they remain poorly understood and often difficult to diagnose. Therefore, a rational diagnostic approach, based on a standardized sequence of laboratory tests, with consecutive steps of increasing level of complexity, plays a crucial role in the diagnosis of most IPFDs. In this review we discuss a diagnostic approach through platelet phenotyping and genotyping and we give an overview of the options for the management of bleeding in these disorders and an account of the few systematic studies on the bleeding risk associated with invasive procedures and its treatment.

Autologous blood preparations rich in platelets, fibrin and growth factors

OBJECTIVES

Bone regeneration is often needed prior to dental implant treatment due to the lack of adequate quantity and quality after infectious diseases. The greatest regenerative power was obtained with autologous tissue, primarily the bone alive, taken from the same site or adjacent sites, up to the use centrifugation of blood with the selection of the parts with the greatest potential regenerative. In fact, various techniques and technologies were chronologically successive to cope with an ever better preparation of these concentrates of blood. Our aim is to review these advances and discuss the ways in which platelet concentrates may provide such unexpected beneficial therapeutic effects.

METHODS

The research has been carried out in the MEDLINE and Cochrane Central Register of Controlled Trials database by choosing keywords as "platelet rich plasma", "platelet rich fibrin", "platelet growth factors", and "bone regeneration" and "dentistry".

RESULTS

Autologous platelet rich plasma is a safe and low cost procedure to deliver growth factors for bone and soft tissue healing.

CONCLUSION

The great heterogeneity of clinical outcomes can be explained by the different PRP products with qualitative and quantitative difference among substance.

Platelet-rich plasma: underlying biology and clinical correlates

Platelet-rich plasma (PRP) has recently become the focus of intensive interest and discussion, in part because of the expanding understanding of platelet function. Anucleate platelets within PRP release a myriad of growth factors and cytokines while contributing to plasma coagulation and fibrin development; the latter acts as vehicle for the local delivery. The biological effects of PRP are largely attributed to the platelet secretome and plasma signaling proteins. Clinical data suggest that PRPs may exploit different regenerative mechanisms under diverse disease conditions, including hemostasis, inflammation, angiogenesis and the synthesis of extracellular matrix. The success of PRP therapies depends on current tissue healing research and the translation of this knowledge into clinical developments.

Inherited, congenital and acquired disorders by hemostasis (vascular, platelet & plasmatic phases) with repercussions in the therapeutic oral sphere

The hemostasis alterations, either congenital or hereditary origin, and acquired, are circumstances that hinder oral care to patients who suffer them and also generates in the professional who has to attend, high stress. Bleeding control once established and dental treatment planning, both in the aspect of preparation, as the realization of the odonto-stomatological therapeutic, has suffered updates that do need to remember certain aspects of the care of these patients. But we must not forget that the hematologist or internist who controls the patient's medical condition, is a cornerstone for the planning and implementation of treatment plans. We must also remember that, in certain circumstances, treatment should be performed in a hospital setting. In this review, we aim to provide the odonto-stomatologist guidance on how to address the problem and provide simple and updated guidelines to apply in the treatment of these people.

Anti-hemorrhagic agents in oral and dental practice: an update

Many oral surgeons in their daily practice have the problem of controlling postoperative bleeding. In surgical, oral and maxillofacial practice, standard anti-hemorrhagic protocols, especially in high risk patients, are obviously required and need to be continuously updated. The purpose of this review is to give a rational insight into the management of bleeding in oral and dental practice through modern drugs and medical devices such as lysine analogues and serine protease inhibitors, desmopressin, fibrin sealants, cyanoacrylates, gelatins, collagen and foams, protein concentrates, recombinant factors, complementary and alternative medicine and other compounds.

What To Do When You Suspect an Inherited Platelet Disorder

Inherited platelet disorders (IPDs) comprise a heterogenous group of diseases that include defects in platelet function and disordered megakaryopoiesis. Some IPDs overlap as both defects in function and thrombopoiesis, resulting in both altered aggregation and/or secretion and thrombocytopenia. This review examines the key features of the presentation of IPDs in children and adults and presents a diagnostic algorithm for the evaluation of these patients. In addition, recent advances in our understanding of the pathophysiology of platelet disorders are addressed, with attention given to some of the novel genetic associations. Finally, treatment options and future therapies are briefly discussed.