Comparative transcriptomic analysis of circulating endothelial cells in sickle cell stroke.

Ischemic stroke (IS) is one of the most impairing complications of sickle cell anemia (SCA), responsible for 20% of mortality in patients. Rheological alterations, adhesive properties of sickle reticulocytes, leukocyte adhesion, inflammation and endothelial dysfunction are related to the vasculopathy observed prior to ischemic events. The role of the vascular endothelium in this complex cascade of mechanisms is emphasized, as well as in the process of ischemia-induced repair and neovascularization. The aim of the present study was to perform a comparative transcriptomic analysis of endothelial colony-forming cells (ECFCs) from SCA patients with and without IS. Next, to gain further insights of the biological relevance of differentially expressed genes (DEGs), functional enrichment analysis, protein-protein interaction network (PPI) construction and in silico prediction of regulatory factors were performed. Among the 2469 DEGs, genes related to cell proliferation (AKT1, E2F1, CDCA5, EGFL7), migration (AKT1, HRAS), angiogenesis (AKT1, EGFL7) and defense response pathways (HRAS, IRF3, TGFB1), important endothelial cell molecular mechanisms in post ischemia repair were identified. Despite the severity of IS in SCA, widely accepted molecular targets are still lacking, especially related to stroke outcome. The comparative analysis of the gene expression profile of ECFCs from IS patients versus controls seems to indicate that there is a persistent angiogenic process even after a long time this complication has occurred. Thus, this is an original study which may lead to new insights into the molecular basis of SCA stroke and contribute to a better understanding of the role of endothelial cells in stroke recovery.

EFFECTIVENESS OF VISCOSUPPLEMENTATION IN THE TREATMENT OF HEMOPHILIC ARTHROPATHY: A SYSTEMATIC REVIEW.

Objective: To describe the efficacy of using viscosupplementation in patients with hemophilic arthropathy (HA), on pain, limb functionality, and quality of life. Methods: A systematic review of the literature was performed following the PRISMA guidelines without limitations of language or year of publication. The search was performed on the following medical databases: PubMed, Cochrane Library, EMBASE, BVS/BIREME, Scopus, Web of Science, EBSCOhost, and PROQUEST in April 2020. The search used the following word: (hemophilia AND joint diseases) OR (haemophilic arthropathy OR hemophilic arthropathy) AND viscosupplementation. Results: The systematic review identified 127 articles, 10 of which were selected for data extraction and qualitative analysis. The 10 selected articles included 297 joints with HA in 177 hemophilic subjects. Our review showed positive results in alleviating pain and improving functional capacity, and quality of life. No major adverse effects were observed. Conclusion: There is a lack of scientific evidence regarding viscosupplementation with hyaluronic acid, but the results presented in this research suggest that it is an effective and safe therapeutic option to alleviate pain and improve functional capacity in patients with HA. Level of Evidence II, Systematic Review.

Objetivo: Descrever o uso da viscossuplementação com ácido hialurônico em pacientes com artropatia hemofílica (HA), sua eficácia na dor, a funcionalidade do membro e a qualidade de vida após sua aplicação. Métodos: Revisão sistemática da literatura (RSL) que seguiu as diretrizes PRISMA, sem limitação de idioma ou ano de publicação. A pesquisa foi realizada em abril de 2020 nas seguintes bases de dados médicas: PubMed, Cochrane Library, EMBASE, BVS/BIREME, Scopus, Web of Science, EBSCOhost e ProQuest. A estratégia de pesquisa foi: (hemofilia AND joint disease) OR (artropatia hemofílica OU artropatia hemofílica) E viscossuplementação. Resultados: A RSL identificou 127 artigos, dos quais 10 foram selecionados para extração de dados e análise qualitativa. Os 10 artigos selecionados incluíram 297 articulações com AH em 177 indivíduos hemofílicos. Nossa revisão mostrou resultados positivos na melhora da dor, na capacidade funcional e na qualidade de vida. Não foram observados efeitos adversos importantes. Conclusão: A evidência científica atual a respeito da viscossuplementação com ácido hialurônico é escassa, mas os resultados apresentados nesta pesquisa sugerem que é uma opção terapêutica eficaz e segura para diminuir a dor e melhorar a capacidade funcional em pacientes com AH. Nível de Evidência II, Revisão Sistemática.

Comparative transcriptome analysis of endothelial progenitor cells of HbSS patients with and without proliferative retinopathy.

Among sickle cell anemia (SCA) complications, proliferative sickle cell retinopathy (PSCR) is one of the most important, being responsible for visual impairment in 10-20% of affected eyes. The aim of this study was to identify differentially expressed genes (DEGs) present in pathways that may be implicated in the pathophysiology of PSCR from the transcriptome profile analysis of endothelial progenitor cells. RNA-Seq was used to compare gene expression profile of circulating endothelial colony-forming cells (ECFCs) from HbSS patients with and without PSCR. Furthermore, functional enrichment analysis and protein-protein interaction (PPI) networks were performed to gain further insights into biological functions. The differential expression analysis identified 501 DEGs, when comparing the groups with and without PSCR. Furthermore, functional enrichment analysis showed associations of the DEGs in 200 biological processes. Among these, regulation of mitogen-activated protein (MAP) kinase activity, positive regulation of phosphatidylinositol 3-kinase (PI3K), and positive regulation of Signal Transducer and Activator of Transcription (STAT) receptor signaling pathway were observed. These pathways are associated with angiogenesis, cell migration, adhesion, differentiation, and proliferation, important processes involved in PSCR pathophysiology. Moreover, our results showed an over-expression of VEGFC (vascular endothelial growth factor-C) and FLT1 (Fms-Related Receptor Tyrosine Kinase 1) genes, when comparing HbSS patients with and without PSCR. These results may indicate a possible association between VEGFC and FLT1 receptor, which may activate signaling pathways such as PI3K/AKT and MAPK/ERK and contribute to the mechanisms implicated in neovascularization. Thus, our findings contain preliminary results that may guide future studies in the field, since the molecular mechanisms of PSCR are still poorly understood.

Effectiveness of viscosupplementation in the treatment of hemophilic arthropathy: a systematic review / Efetividade da viscossuplementação no tratamento da artropatia hemofílica: uma revisão sistemática

ABSTRACT Objective: To describe the efficacy of using viscosupplementation in patients with hemophilic arthropathy (HA), on pain, limb functionality, and quality of life. Methods: A systematic review of the literature was performed following the PRISMA guidelines without limitations of language or year of publication. The search was performed on the following medical databases: PubMed, Cochrane Library, EMBASE, BVS/BIREME, Scopus, Web of Science, EBSCOhost, and PROQUEST in April 2020. The search used the following word: (hemophilia AND joint diseases) OR (haemophilic arthropathy OR hemophilic arthropathy) AND viscosupplementation. Results: The systematic review identified 127 articles, 10 of which were selected for data extraction and qualitative analysis. The 10 selected articles included 297 joints with HA in 177 hemophilic subjects. Our review showed positive results in alleviating pain and improving functional capacity, and quality of life. No major adverse effects were observed. Conclusion: There is a lack of scientific evidence regarding viscosupplementation with hyaluronic acid, but the results presented in this research suggest that it is an effective and safe therapeutic option to alleviate pain and improve functional capacity in patients with HA. Level of Evidence II, Systematic Review.

RESUMO Objetivo: Descrever o uso da viscossuplementação com ácido hialurônico em pacientes com artropatia hemofílica (HA), sua eficácia na dor, a funcionalidade do membro e a qualidade de vida após sua aplicação. Métodos: Revisão sistemática da literatura (RSL) que seguiu as diretrizes PRISMA, sem limitação de idioma ou ano de publicação. A pesquisa foi realizada em abril de 2020 nas seguintes bases de dados médicas: PubMed, Cochrane Library, EMBASE, BVS/BIREME, Scopus, Web of Science, EBSCOhost e ProQuest. A estratégia de pesquisa foi: (hemofilia AND joint disease) OR (artropatia hemofílica OU artropatia hemofílica) E viscossuplementação. Resultados: A RSL identificou 127 artigos, dos quais 10 foram selecionados para extração de dados e análise qualitativa. Os 10 artigos selecionados incluíram 297 articulações com AH em 177 indivíduos hemofílicos. Nossa revisão mostrou resultados positivos na melhora da dor, na capacidade funcional e na qualidade de vida. Não foram observados efeitos adversos importantes. Conclusão: A evidência científica atual a respeito da viscossuplementação com ácido hialurônico é escassa, mas os resultados apresentados nesta pesquisa sugerem que é uma opção terapêutica eficaz e segura para diminuir a dor e melhorar a capacidade funcional em pacientes com AH. Nível de Evidência II, Revisão Sistemática.

Extended half-life recombinant factor VIII treatment of hemophilia A in Brazil: an expert consensus statement.

INTRODUCTION: Treatment of hemophilia A in Brazil is offered to all patients at no cost. However, several unmet medical needs exist. METHOD: In this study, we applied the Delphi method to discuss with seven hemophilia A specialists the challenges that patients and the health system face regarding hemophilia A treatment and opportunities for improvement. RESULTS: A consensus was obtained regarding the number of weekly infusions and patient adherence to treatment. The bleeding profile, unfavourable pharmacokinetics (PKs), low adherence and high daily activity were patient profiles that would benefit from using the extended half-life (EHL) recombinant factor VIII (rFVIII). The advantages of treatment with the EHL rFVIII were the lower number of infusions per week, which could increase patient adherence and decrease the risk of bleeds, due to a more constant plasma level, a lower value. Additionally, the EHL rFVIII could improve quality of life, especially in patients with high daily activity, such as adolescents and young adults. The panelists mentioned that EHL rFVIII, if available, could be offered first to the priority group (adolescents between 12 and 19 years old), followed by adults (20 to 64 years old) and elderly people (over 65 years old). CONCLUSION: In summary, the EHL rFVIII offers the optimal prophylaxis by decreasing the dose frequency, increasing the treatment adherence and improving the QoL, without compromising safety and efficacy.

Prolonged APTT of unknown etiology: A systematic evaluation of causes and laboratory resource use in an outpatient hemostasis academic unit.

BACKGROUND: A prolonged activated partial thromboplastin time (APTT) of unknown cause is one of the most frequent reasons why outpatients are referred for hemostasis consultation. Nevertheless, very few data are available on the relative contribution of individual causes of this common clinical scenario. Here, we present a systematic evaluation of all causes of APTT prolongation in a consecutive population of outpatients referred for specialized hemostasis consultation during a 14-year period. METHODS: All cases referred to an academic specialized hemostasis outpatient unit due to APTT prolongation of unknown etiology whose prolonged APTT was confirmed in the first visit were included in the study. Data were obtained from the electronic medical records. RESULTS: Among 187 consecutive patients, the most frequent causes were antiphospholipid antibodies in 22.6%, contact pathway factor deficiencies in 17.4%, other coagulation factor deficiencies in 11.6%, and vitamin K deficiency/liver disease in 11.6%. A definite cause was not identified in 22.1% of patients. Presence of antiphospholipid antibodies, and absence of bleeding symptoms were both associated with significantly longer APTT values compared to other categories/clinical scenarios. The investigation of each case required a mean of 18.2 additional tests per patient, with estimated costs ranging from US$191.60 to US$1055.60. CONCLUSIONS: Our results describe the main causes of APTT prolongation in outpatients, as well as estimates of resource use required to investigate this condition, thus providing evidence supporting the importance of measures to minimize the indiscriminate use of this assay.

Intermittent low platelet counts hampering diagnosis of X-linked thrombocytopenia in children: report of two unrelated cases and a novel mutation in the gene coding for the Wiskott-Aldrich syndrome protein.

BACKGROUND: Thrombocytopenia can occur in different circumstances during childhood and although immune thrombocytopenia is its most frequent cause, it is important to consider other conditions, especially when there is a persistent or recurrent low platelet count. We report two cases of intermittent thrombocytopenia, previously misdiagnosed as immune thrombocytopenia. CASES PRESENTATION: Both cases described were boys who presented with an intermittent pattern of thrombocytopenia, with a persistently low mean platelet volume. In both patients, peripheral blood smear revealed small platelets and flow cytometry showed low expression of Wiskott-Aldrich syndrome protein (WASP) in leucocytes. Molecular analysis of the first case identified a mutation in exon 2 of the gene coding for WASP, leading to a p.Thr45Met amino acid change and confirming the diagnosis of X-linked thrombocytopenia. In the second case, a novel missense mutation in exon 2 of the gene coding for WASP was detected, which resulted in a p.Pro58Leu amino acid change. CONCLUSION: These two rare presentations of thrombocytopenia highlight the importance of evaluating the peripheral blood smear in the presence of recurrent or persistent thrombocytopenia and show that failing to do so can lead to misdiagnoses. Since thrombocytopenia may be found in pediatric outpatient clinic, increased awareness among general pediatricians will help to improve the differential diagnosis of this condition.

Heat treatment of samples improve the performance of the Nijmegen-Bethesda assay in hemophilia A patients undergoing immune tolerance induction.

Nijmegen-Bethesda assay is the gold standard to assess inhibitory antibodies against factor (F) VIII. This method has some limitations, including high coefficient of variation and possible interference of residual endogenous or exogenous factor VIII. Heat-treatment of samples at 56 °C for 30 min could be a strategy to improve the sensitivity of this test. The aim of this study was to compare inhibitor quantification in hemophilia patients with and without inhibitor performed in previously heated and non-heated samples. A total of 109 analyses from 46 patients with severe hemophilia A were performed. Patients were divided into three groups: 20 patients with no history of inhibitor, recently and not recently exposed to FVIII (group I), 21 patients with history of inhibitor not exposed to FVIII (group II), and 5 patients (68 samples) undergoing an immune tolerance induction (ITI) protocol (group III). For patients with no history of inhibitor, heat-treatment did not modify the results (p=0.24). However, differences in inhibitor levels between heated and non-heated samples were observed in patients with history of inhibitor (group II, p<0.05) and in patients in ITI (group III, p<0.001). In 11 samples, inhibitor quantification shifted from negative to positive. Additionally, a longitudinal evaluation of each ITI patient showed similar trend line for the results of heated and non-heated samples. In this study, we demonstrated that heating samples increase sensitivity of Nijmegen-Bethesda assay, with no shift from negative to positive results in patients with no history of inhibitor. Furthermore, this procedure has an important role to patients undergoing an ITI protocol.

Desenvolvimento de um Serious Game para crianças com hemofilia / Development of a serious game for children with hemophilia / Desarrollo de un serious game para niños con hemofilia

This work describes the development process of the interface of an educational game that is aimed at children with hemophilia. The development and evaluation process used the dynamic Braindraw, Participatory Heuristic Evaluation and Beta Test and involved the end users of the game: children with hemophilia. The hypothesis is that children learn more about the disease through the game, which motivates them in an interactive practice. The experiments performed confirmed that the children with hemophilia learned more about the disease with the game...

Este trabalho descreve o processo de desenvolvimento da interface de um jogo educativo destinado à crianças com hemofillia. O processo de desenvolvimento e avaliação foram realizados através das dinâmicas Braindraw, Avaliação Heurística Participativa e Teste Beta e envolveu os usuários finais do jogo: crianças com hemofilia. A hipótese é que a criança com hemofilia parende mais sobre a doença através de um jogo, que as motiva de foma prática e interativa. Os experimentos realizados confirmaram que as crianças com hemofilia aprenderam mais sobre a doença com o jogo...

Este artículo describe el proceso de desarrollo de un juego educativo destinado a la interfaz hemofilia niños. El proceso de desarrollo y la evaluación se realizó mediante las dinámica Braindraw, Evaluación Heurística Participativa y Pruebas Beta y los usuarios finales involucrados en el juego: los niños con hemofilia. La hipótesis es que los niños con hemofilia parende más acerca de la enfermedad a través de un juego, lo que motiva la foma práctica e interactiva. Los experimentos confirmaron que los niños con hemofilia han aprendido más acerca de la enfermedad con el juego...

Increased adhesive and inflammatory properties in blood outgrowth endothelial cells from sickle cell anemia patients.

The endothelium plays an important role in sickle cell anemia (SCA) pathophysiology, interacting with red cells, leukocytes and platelets during the vaso-occlusive process and undergoing activation and dysfunction as a result of intravascular hemolysis and chronic inflammation. Blood outgrowth endothelial cells (BOECs) can be isolated from adult peripheral blood and have been used in diverse studies, since they have a high proliferative capacity and a stable phenotype during in vitro culture. This study aimed to establish BOEC cultures for use as an in vitro study model for endothelial function in sickle cell anemia. Once established, BOECs from steady-state SCA individuals (SCA BOECs) were characterized for their adhesive and inflammatory properties, in comparison to BOECs from healthy control individuals (CON BOECs). Cell adhesion assays demonstrated that control individual red cells adhered significantly more to SCA BOEC than to CON BOEC. Despite these increased adhesive properties, SCA BOECs did not demonstrate significant differences in their expression of major endothelial adhesion molecules, compared to CON BOECs. SCA BOECs were also found to be pro-inflammatory, producing a significantly higher quantity of the cytokine, IL-8, than CON BOECs. From the results obtained, we suggest that BOEC may be a good model for the in vitro study of SCA. Data indicate that endothelial cells of sickle cell anemia patients may have abnormal inflammatory and adhesive properties even outside of the chronic inflammatory and vaso-occlusive environment of patients.

Molecular genetic testing of hemostasis and thrombosis in developing countries: achievements, hopes, and challenges.

In today's developing world, how do we define a "developing country"? What level of effort and resources is invested in diagnosis, patient care, and research in those countries that we define to be developing? In particular, what is the situation with respect to molecular genetic testing in these countries? How much has been achieved to date, and what are the challenges to further achievements? This article describes the current status, challenges, and future hopes with respect to molecular genetic testing in hemostasis and thrombosis from the perspective of experts from three countries: Brazil, Colombia, and Iran. These individuals have lived and practiced genetic testing in their countries and have also had the experience to work and/or interact with the developed world to enable an appreciation of the difference.

Efficacy and safety of dapsone as a second-line treatment in non-splenectomized adults with immune thrombocytopenic purpura.

In adults with immune thrombocytopenic purpura (ITP), steroids are usually proposed as first-line therapy, but long-term complete responses are obtained in no more than 20% of patients. For the remaining patients, splenectomy is considered the treatment of choice, with reported "cure" rates from 60-70%. However, the inherent risks of surgery and sepsis after splenectomy without a guarantee of success justify the search for strategies aimed to avoid splenectomy. Here we retrospectively evaluated the results of dapsone treatment in ITP patients that failed first-line therapy with steroids. These patients received dapsone 100 mg/day for a minimum of 30 days before splenectomy was considered. Efficacy was defined as a sustained rise in platelet counts (>50 x 10(9)/l) clearly attributed to dapsone treatment. Among 52 steroid-dependent or refractory patients, dapsone resulted in sustained increases in platelet counts in 44.2% of patients, after a median follow-up of 21.10 months after treatment initiation. The long-term efficacy of dapsone in this setting is further corroborated by the observation that none of the "responding" patients required splenectomy in the follow-up, compared to 69.0% of the "non-responding" patients. Dapsone-related adverse events were mild and promptly reversed by treatment withdrawal. The results of our retrospective analysis suggest that dapsone is a safe and effective second-line agent for steroid-dependent or refractory ITP patients. Because of its well-known safety profile and low cost compared to other potential second-line treatments for ITP, a trial course of dapsone should be viewed as an attractive option before splenectomy in steroid-dependent of refractory adult ITP patients.

Diagnosis and treatment of congenital hemophilia with inhibitors a Latin American perspective.

The Committee of Latin America on the Therapeutics of Inhibitor Groups (CLOTTING) is composed of a number of hemophilia specialists from Latin America. The group aims to encourage the adoption of a good standard of care for Latin American patients with hemophilia. The occurrence of inhibitors in patients with hemophilia poses clinical challenges, and it is estimated that between 1000 and 3000 patients in Latin America are affected by hemophilia with inhibitors. There is an urgent need to establish a regional consensus and clinical guidelines for the diagnosis and treatment of these patients. We present an extensive review based on best current clinical practice and published literature, as seen from a Latin American perspective, taking into account the variable nature of hemophilia care available in the various countries in this Region.

Association between estrogen receptor alpha and beta gene polymorphisms and deep vein thrombosis.

BACKGROUND: Estrogen and the estrogen receptors alpha (ESR1) and beta (ESR2) play a role in regulating genes, including coagulation and fibrinolysis genes. OBJECTIVE: We investigated the association between ESR1 c.454-397T>C and c.454-351A>G and ESR2 1082A>G and 1730A>G polymorphisms and the risk of deep vein thrombosis (DVT), in 134 patients and 134 controls with acquired risk factors for thrombosis associated with estrogen alterations, such as pregnancy, puerperium, oral contraceptives (OC), and hormone replacement therapy (HRT). We also analysed 134 men with DVT. We investigated the relationship of these polymorphisms and the levels of fibrinogen, protein C (PC), protein S (PS), and antithrombin (AT) activity. METHODS: Gene polymorphisms were identified by using PCR and RFLP. Coagulation methods were used to measure PC, PS, and fibrinogen. Chromogenic methods were used to quantify AT. RESULTS AND CONCLUSIONS: The presence of the AA genotype of the 1730G>A polymorphism (OR=0.18; 95%CI=0.05-0.62) suggests a protective effect for DVT in women using OC. As the GG genotype of the 1730G>A polymorphism is associated with increased PS activity in all control women and women using OC, this suggested that a protective effect must occur by another pathway not related to PS. The AA and AG genotypes of the c.454-351A>G and GG genotype of the 1082G>A polymorphisms are associated with increased fibrinogen concentration in pregnant women. The GG haplotype in the ESR2 gene (P<0.001) was related to factor V Leiden or G20210A mutation in the prothrombin gene, or both, as predictive factors of DVT.

Use of recombinant factor VIIa in the management of severe bleeding episodes in patients with Bernard-Soulier syndrome.

Bernard-Soulier syndrome (BSS) is a rare congenital platelet disorder characterized by defective platelet adhesion and manifested by spontaneous and often profuse bleeding. Recombinant factor VIIa (rFVIIa) is a haemostatic agent licensed for the treatment of bleeding episodes in patients with haemophilia and inhibitors, which may represent a low-risk alternative to existing therapies in the management of patients with BSS. Here, we describe the use of rFVIIa for the treatment of three severe bleeding episodes in two patients with BSS. Data were extracted by automated searching of the international, Internet-based registry http://www.haemostasis.com . Patient 1, a 24-year-old woman, was admitted with severe epistaxis and hypotension. The diagnosis of BSS was confirmed by macrothrombocytopenia, absence of ristocetin-induced platelet agglutination (RIPA) and absence of glycoprotein (GP) Ibalpha and IX on the platelet surface. Epsilon aminocaproic acid (EACA; two 50-mg/kg doses), packed red blood cells (PRBCs, 2 U) and platelets (30 U) failed to control the bleeding and, after 13 h, three bolus doses of rFVIIa (90 microg/kg body weight) and a third dose of EACA were administered; bleeding stopped after the third dose of rFVIIa. Patient 2, a 15-year-old girl, initially presented with severe menorrhagia. A lack of RIPA and severe deficiency of GPIbalpha on the platelet surface confirmed the diagnosis of BSS. EACA and fresh-frozen plasma did not control the haemorrhage, but two bolus doses of rFVIIa (98 microg/kg body weight) resulted in a marked decrease in bleeding. On second admission, patient 2 had severe epistaxis and mild menorrhagia. Two rFVIIa doses (98 and 122.5 microg/kg body weight) were given, and the bleeding stopped. No adverse events were reported in these cases. These three admissions highlight the potential of rFVIIa for the treatment of severe bleeds in patients with BSS.

Effects of high platelet concentration in collecting and freezing dry platelets concentrates.

OBJECTIVE: To evaluate, in vitro, the effects of collecting and cryopreserving fresh dry platelet concentrates (PCs). MATERIAL AND METHODS: Standard and dry PCs were collected in the same apheresis procedure. PCs were evaluated by mean platelet volume (MPV), pH, glucose and LDH levels. Activation was examined by flow cytometry using anti-CD41, anti-CD42 and anti-CD62p monoclonal antibodies and annexin binding assay. Platelet function was assessed by aggregation using ADP, collagen and arachidonic acid as agonists. Dry PCs were compared to standard PCs and to cryopreserved dry PCs. We also compared the use of ThromboSol to 5% DMSO as cryoprotectives. RESULTS: Dry PCs presented a significantly reduced pH and glucose (p<0.001), increased LDH levels and CD62p expression (p<0.001) and diminished aggregation response to ADP (p<0.001). Platelet cryopreservation was associated with platelet lysis, activation and loss of function. Dry PCs cryopreserved with TS were associated with statistically higher LDH levels (p<0.001) and a higher percentage of annexin binding (p=0.005), in addition to a lower number of CD42 positive platelets (p=0.01). CONCLUSION: Dry PCs should be rapidly frozen after collection to avoid a fall in pH and platelet activation. 5% DMSO performed better than TS to cryopreserve dry PCs.