Platelets
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MicroRNAs (miRNAs) are small non-coding RNAs involved in the regulation of gene expression. Dysregulated expression of several miRNAs has been found in primary immune thrombocytopenia (ITP) suggesting that miRNAs are likely involved in the pathogenesis of ITP. We aimed to explore the differential expression of miRNAs in patients with ITP before and after starting treatment with thrombopoietin-receptor agonists (TPO-RAs) to clarify their roles in the pathophysiology of ITP, and as potential diagnostic and prognostic markers of this disorder. ⋯ ROC curve analysis showed that the combination of miR-199a-5p and miR-33a-5p could distinguish patients with ITP from controls with AUC of 0.93. This study identifies a number of differentially expressed miRNAs in ITP patients before and after initiation of TPO-RAs with potential roles in the pathophysiology, as well as with a possible utility as diagnostic and prognostic biomarkers. These interesting findings deserve further exploration and validation in future studies.
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Burn injury has severe impact on the physiologic homeostasis. Platelet counts show a distinct course post-burn injury, with a nadir at day 3 followed by a thrombocytotic period with at peak at day 15, with a gradual return to normal. So far, it is unknown how the functionality and activational status of platelets develop post burn. ⋯ Growth factor content followed the same course as the platelet count, reflecting a constant growth factor per platelet ratio. Concluding, platelets post burn-injury appears to be functional and not overly activated. However, burn patients seem to remain in a procoagulant state for an extensive period, which may impact their pathology.
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The effect of CYP2C19 gene polymorphism on clinical outcomes of patients with coronary artery disease (CAD) treated with clopidogrel remains controversial. Ethnicity has been proposed to influence clopidogrel response following stent implantation in CAD patients with different CYP2C19 genotypes. Furthermore, Asian populations are reported to have a relatively greater prevalence of CYP2C19 loss-of-function (LOF) alleles. ⋯ Subgroup analysis between three nationalities of China, Korea, and Japan demonstrated that the risk of MACE among Chinese LOF allele carriers was the greatest (OR: 2.28; 95% CI:1.91 to 2.73). In conclusion, among Asian populations with CAD undergoing stent implantation, CYP2C19 LOF allele carriers are at greater risk of adverse cardiovascular events and lower risk of bleeding compared with non-carriers. Genetic testing may be helpful for clinicians to personalize antiplatelet therapy especially in Asian population.
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The aim of the present study was to evaluate the effect of injectable platelet-rich fibrin (i-PRF) on cultivated chondrocytes and osteochondral regeneration in critical-sized osteochondral defect of the rabbit's knee in comparison to autologous platelet-rich plasma (PRP). Chondrocytes were first investigated for their ability to proliferate and differentiate in response to PRP and i-PRF. Thereafter, full-thickness critical-sized osteochondral defects 5 mm in diameter and 5 mm in depth were created in the knee joint of 12 adult female New Zealand White rabbits. ⋯ In conclusion, the use of i-PRF using the low speed centrifugation concept significantly promoted chondrocyte activity and further improved cartilage regeneration when compared to PRP. The histological results revealed early and better cartilage regeneration within 4 weeks postoperatively when i-PRF was utilized and the results were maintained at 12 weeks. Future clinical studies are now needed investigating the regenerative potential of i-PRF in comparison to PRP for knee regeneration.
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Multicenter Study
Diagnosis and treatment of MYH9-RD in an Australasian cohort with thrombocytopenia.
MYH9-related disorders (MYH9-RDs) caused by mutation of the MYH9 gene which encodes non-muscle myosin heavy-chain-IIA (NMMHC-IIA), an important motor protein in hemopoietic cells, are the most commonly encountered cause of inherited macrothrombocytopenia. Despite distinguishing features including an autosomal dominant mode of inheritance, giant platelets on the peripheral blood film accompanied by leucocytes with cytoplasmic inclusion bodies (döhle-like bodies), these disorders remain generally under-recognized and often misdiagnosed as immune thrombocytopenia (ITP). This may result in inappropriate treatment with corticosteroids, immunosupressants and in some cases, splenectomy. ⋯ In addition, we undertook IF staining in a proportion of cases and confirm that this test and/or NGS are satisfactory diagnostic tests. We propose that fewer cases of MYH9-RDs would be missed if diagnostic algorithms prioritized IF and/or NGS in cases of thrombocytopenia associated with giant platelets, even if döhle-like bodies are not appreciated on the peripheral blood film. Finally, our report describes the long-term use of a thrombopoietin agonist in a case of MYH9-RD that had previously been diagnosed as ITP, and demonstrates that treatment with these agents may be possible, and is well tolerated, in this group of patients.