Contagem de plaquetas: avaliação de metodologias manuais e aplicação na rotina laboratorial

Comar, Samuel Ricardo; Danchura, Heloísa S. M.; Silva, Paulo H.

doi:10.1590/s1516-84842009005000087

Cited by 10 publications

(9 citation statements)

References 27 publications

(34 reference statements)

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“…Regarding the increase in the number of platelets observed in the samples after storage, Comar et al (2009) stated that the presence of red cell fragments, cytoplasmic leukemic cells, blood lipids, bacteria, yeast and microcytes with volumes close to the platelets, can all be counted by hematology analyzers, leading to a false increased platelet count.…”

Section: Resultsmentioning

confidence: 99%

Conservation and viability of refrigerated platelet-rich plasma from New Zealand rabbits

Silva

Eurides

Andrade

et al. 2016

SCA

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Fifteen male New Zealand rabbits were used in this study, with the aim of storing their platelet-rich plasma (PRP) for 30 days at 4-6 °C to investigate its conservation and viability during this period. Thirty samples of PRP were prepared and sorted into three equal groups (G1, G2, and G3), and every three days a sample was taken out for evaluationof the number of platelets, mean platelet volume (MPV), pH of the plasma, aggregation post addition of calcium thromboplastin, and for the presence of bacterial and fungal contamination. Results suggested that, for the number of platelets, there was no linear relationship over time. However, when comparing the number of platelets pre-storage to that post-storage, a statistical difference was observed. The hemogram MPV variables, pre and post-storage, also did not relate with time however, there was a statistical difference between the MPV of hemogram and MPV pre-storage, and between MPV pre-storage and MPV post-storage. From the pH evaluation, no influence of time on the variables was found, but statistical differences were found in the samples after storage between 30 and 6 days, 30 and 24 days, and 30 and 27 days. Platelet aggregation occurred within twenty seconds in all samples, independent of storage time. There was no growth of bacteria or yeast in any sample; however, mold growth occurred in the samples stored for 21 days from G1 and G3. It can be concluded that the PRP of rabbits can be stored in 4-6 °C refrigeration for up to18 days and still maintain the number of platelets, with no significant pH alteration or bacterial or fungal contamination. Key words: Platelet aggregation. Platelet concentrate. Storage. ResumoQuinze coelhos machos da raça Nova Zelândia foram utilizados neste experimento, com a finalidade de armazenar o plasma rico em plaquetas (PRP) durante 30 dias a 4-6°C para investigar a sua conservação e viabilidade durante este período. Trinta amostras de PRP foram preparadas e divididos em três grupos iguais (G1, G2 e G3), e de três em três dias foi retirada uma amostra para avaliação do número de plaquetas, volume plaquetário médio (VPM), pH do plasma, agregação após adição de tromboplastina cálcica, e para a presença de contaminação bacteriana e fúngica. Os resultados sugerem que, para o número de plaquetas, não houve uma relação linear com o tempo. No entanto, quando se compara o número de plaquetas pré-armazenamento com o pós-armazenamento, foi observada diferença estatística. As variáveis VPM no hemograma, pré e pós-armazenamento, também não se relacionou com o tempo, porém, houve diferença estatística entre o VPM do hemograma e pré-armazenamento, e entre VPM pré-armazenamento e pós-armazenamento. A partir da avaliação do pH, não houve influência do tempo sobre as variáveis, porém foram encontradas diferenças estatísticas nas amostras após o armazenamento entre 30 e 6, 30 e 24, e 30 e 27 dias. A agregação de plaquetas ocorreu no prazo de vinte segundos, em todas as amostras, independente do tempo de armazenamento. Não houve cresciment...

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Section: Resultsmentioning

confidence: 99%

Conservation and viability of refrigerated platelet-rich plasma from New Zealand rabbits

Silva

Eurides

Andrade

et al. 2016

SCA

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“…The PC and the platelet evaluation on slides is fundamental to evaluate patients with diseases affecting the platelets, and it is useful to perform an internal control in the quality of automated counts [21]. The result of the PC is usually normal, but in patients with the type 2B, thrombocytopenia might be observed [13].…”

Section: Screening Testsmentioning

confidence: 99%

“…The most recent method has been proposed by ISLH (International Society for Laboratory Hematology) as the new reference method using specific fluorescent monoclonal antibodies against the superficial glycoproteins from the platelet membranes observed by flow cytometry. The only available haematological equipment that offers this technology is the Cell-Dyn 4000 or Cell-Dyn Sapphire (Abbott Diagnostics) [21].…”

Section: Screening Testsmentioning

confidence: 99%

Von Willebrand Disease Lab Diagnosis

Faria¹,

Henneberg

Nascimento

et al. 2015

Indian J Hematol Blood Transfus

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C), VWF binding to immobilized collagen (VWF:CB), ristocetin-induced platelet aggregation (RIPA), VWF multimers patterns, factor VIII binding of immobilized VWF (VWF:FVIIIB), among others. From the moment the diagnosis is confirmed, the appropriate treatment for each patient is sought, with the purpose of increasing plasma concentrations of the deficient protein, both in bleeding episodes, as for invasive procedures. Although diagnosis facilitates treatment other approach in the present scenario is prenatal diagnosis which, is the need of the hour.

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“…Platelets are produced in the bone marrow from cytoplasmic fragments from megakaryocytes and have essential functions in healing, reepithelization, and conservation of vascular integrity through interactions with endothelial cells (Comar et al 2009). Numerous growth factors (GFs) are stored inside α-granules in the platelets, and once released will act on regulatory processes, including tissue regeneration, chemotaxis, cell proliferation, angiogenesis, immunological regulation and modulation of inflammatory processes (Anitua et al 2004).…”

Section: Introductionmentioning

confidence: 99%

Protocols for preparation of platelet rich plasma (PRP) in Quarter Horses

et al. 2019

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RESUMO.-[Protocolos para o preparo de plasma rico em plaquetas (PRP) em cavalos Quarto de Milha.] Este estudo comparou dois protocolos de preparo de plasma rico em plaquetas (PRP) e avaliou a associação entre dois métodos de contagem plaquetária -um manual e o outro automático através de um estudo prospectivo. Sangue venoso de oito equinos da raça Quarto de Milha foi coletado e em seguida foi centrifugado duas vezes utilizando-se dois protocolos distintos: um com descanso antes da primeira centrifugação e outro após a segunda centrifugação. A contagem plaquetária ao início, no meio e ao final dos protocolos foi realizada manualmente e pelo método automatizado, seguida de comparação entre os dois métodos. Para investigar a degranulação plaquetária ocorrida durante o preparo do PRP, o fator de crescimento vascular endotelial (VEGF) foi mensurado em cada estágio dos protocolos. O método utilizando o descanso da amostra antes da primeira centrifugação proporcionou a obtenção de um PRP mais concentrado, além de o estudo verificar que ambos os métodos de contagem plaquetária (manual e automatizado) ABSTRACT.-Miranda S., Mello Costa M.F., Rebouças N., Ramos M.T., Lessa D.A.B. & Alencar N.X. 2019. Protocols for preparation of platelet rich plasma (PRP) in Quarter Horses. Pesquisa Veterinária Brasileira 39 (8):614-621. This study compared two protocols for preparation of platelet rich plasma (PRP) and evaluated the association between manual and automated methods for platelet count using a prospective study design. Eight clinically healthy Quarter Horses had venous blood samples collected at rest. After collection, blood samples were centrifuged twice, using two different protocols including a period of sample resting, either at the start or at the end of the protocol. Platelet counting at the start of the protocol, during, and after obtaining PRP was conducted manually or with an automated counter, followed by comparison of the two methods. In order to investigate platelet degranulation during the protocol, vascular endothelial growth factor (VEGF) was measured at each preparation stage. The protocol with sample resting before centrifugation yielded a more concentrated PRP, and the study verified that both manual and automated methods are comparable and can be used interchangeably for platelet counting. VEGF concentration did not differ significantly between protocols, or among protocol stages.The results indicate that choice of protocol for PRP preparation will affect the quantity of platelets in the final product, although platelet degranulation was not observed as evidenced by the stable VEGF concentrations measured. A larger yield of non-degranulated platelets in PRP is desirable since more α-granules will be present, therefore Protocol II is recommended. Both manual and automated counts reliably allow clinicians to obtain platelet counts and the choice of utilizing a manual or automated method is unlikely to interfere with evaluation of the final PRP product.

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Contagem de plaquetas: avaliação de metodologias manuais e aplicação na rotina laboratorial

Cited by 10 publications

References 27 publications

Conservation and viability of refrigerated platelet-rich plasma from New Zealand rabbits

Conservation and viability of refrigerated platelet-rich plasma from New Zealand rabbits

Von Willebrand Disease Lab Diagnosis

Protocols for preparation of platelet rich plasma (PRP) in Quarter Horses

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