Sangue periférico como fonte de células para terapia celular Peripheral blood as a source of stem cells

O sangue periférico tem sido utilizado como fonte de células progenitoras hematopoéticas para o transplante de medula óssea, única aplicação clínica bem estabelecida até o momento para as células-tronco. Mais recentemente, além das células progenitoras hematopoéticas, estudos têm identificado também no sangue periférico a presença de células-tronco mesenquimais. Estas células apresentam as mesmas características e marcadores de superfície que as células-tronco mesenquimais da medula óssea e são capazes de diferenciação em células do tecido conjuntivo como osteócitos, condrócitos, adipócitos e miócitos. Embora sua origem e destino ainda sejam desconhecidos, a presença destas células no sangue periférico de indivíduos adultos representa um importante instrumento na área de medicina regenerativa e terapia celular. O conhecimento de marcadores imunofenotípicos que possam caracterizar as CTM de forma mais prática e objetiva e de possíveis estratégias capazes de aumentar o número destas células na circulação são fundamentais para o avanço de pesquisas clínicas baseadas na sua utilização.<br>Peripheral blood has been routinely used as a source of hematopoietic progenitor cells for allogeneic and autologous bone marrow transplantation. Recent studies have demonstrated that a low number of mesenchymal stem cells are also present in the peripheral blood. They share the same surface markers as bone marrow-derived mesenchymal stem cells and are capable of differentiating into mesenchymal lineage cells including osteocytes, adipocytes and chondrocytes. Although their origin and destination are unclear, their presence in the peripheral blood of adults seems to represent an important and powerful tool for regenerative medicine and cell therapy

Collection of peripheral blood progenitor cell after administration of cyclophosphamide and granulocyte-colony stimulating factor (GCSF): an analysis of 307 patients

Mobilização inadequada de células progenitoras hematopoéticas (CPH) tem sido observada em 10 - 30% dos pacientes submetidos a transplante de medula óssea (TMO) autogênico para tratamento de doenças onco-hematológicas. Os fatores relacionados com má resposta à mobilização ainda não estão totalmente estabelecidos. Apresentamos uma análise retrospectiva de pacientes submetidos à TMO autogênico com o objetivo de identificar variáveis associadas com resposta ruim ao regime de mobilização utilizado. Casuística e Métodos: Fizeram parte desta análise 307 pacientes com diferentes diagnósticos, tratados com TMO autogênico em uma única Instituição, no período de Abril de 2001 a Abril de 2007. Todos os pacientes incluídos no estudo foram submetidos a um único regime de mobilização baseado na administração de ciclofosfamida (dose total de 60-120 mg/kg de peso IV) e fator estimulador de colônias de granulócitos (G-CSF) (dose diária de 6 - 17 ug/(kg de peso)/dia SC). O sucesso na resposta ao regime de mobilização foi definido quando um número maior ou igual a 2,0x10 (6) células CD34 + /(kg de peso) foi coletado do sangue periférico com até três procedimentos de leucaférese. Resultados: Dos pacientes analisados, 260 apresentaram sucesso na mobilização (84,7%). Nestes pacientes, um número mediano de 3,67 (2,0 - 46,0) células CD34+ /(kg de peso) foi coletado por paciente com um número mediano de 1 (1-3) procedimento de leucaférese. O insucesso na mobilização foi observado em 47 pacientes (15,3%): 24 (7,8%) que foram submetidos à coleta de CPH de sangue periférico, porém não coletaram número maior ou igual 2,0x10 (6) células CD34+/(kg de peso) com pelo menos três procedimentos de leucaférese; e, 23 (7,5%) foram submetidos à coleta de CPH por punção da medula óssea, por não terem atingido número mínimo de 10 células CD34+/mm3 no sangue periférico para realização de leucaférese. De acordo com análise univariada, os fatores associados com o insucesso foram: diagnóstico (P ou = a 2,0x10(6) CD34+ cells/(kg weight) could be collected from the peripheral blood with a maximum of three leukapheresis procedures. Clinical and laboratory parameters at the time of mobilization were analyzed for correlations with the number of CD34+ cells collected. Results: Two hundred and sixty patients (84.7%) presented success in mobilization. In this group, a median of 3.67 (2.0-46.0) CD34+ cells/(kg weight) was collected per patient in a median of 1(1-3) leukapheresis procedure. Poor response to mobilization was observed in 47 patients (15.3%): 24 (7.8%) were submitted to PBSC collection but didn\'t collected at least 2.0 x 106 CD34+ cells/(kg weight) with three leukapheresis procedures and 23 (7.5%) didn\'t reach an absolute number count of 10 CD34+ cells/mm3 in the peripheral blood to start collection by leukapheresis. In univariate analysis poorer PBSC mobilization was associated with diagnosis (Pp < 0.0001), time interval from the diagnosis to mobilization (P < 0.0001), number of cycles of previous chemotherapy (P = 0.0001), previous treatment with alkylating agents (P = 0.0003) and mitoxantrone (P = 0.0006), platelet count <150.000/mm3 before mobilization (P = 0.0006) and interval between mobilization and peak of CD34+ cells in peripheral blood (P < 0.0001). No significant correlation was found with age, gender, disease status, marrow involvement at mobilization, prior radiation therapy and exposition to platin analogues. In the stepwise regression model, diagnosis (P = 0.0232), number of cycles of previous chemotherapy (P = 0.0167), previous treatment with mitoxantrone (P = 0.0285) and platelet count <150.000/mm3 before mobilization (P = 0.0423) were found to be independent negative predictive factors for CD34+ cells mobilization. Conclusion: Cumulative load of chemotherapy, exposition to Mitoxantrone, platelet count just prior to mobilization and diagnosis were independent factors related to poor progenitor cells mobilization. These results could help in the previously recognition of patients at risk for poor or no response to mobilization and allow to plan an alternative or more aggressive regimen for this group of patients

Virus SEN: epidemiologia e sua relação com doenças hepáticas SEN virus: epidemiology and its relation to liver disease

Um vírus recentemente identificado e denominado como vírus SEN (SENV) tem sido considerado como um possível agente causador das hepatites não A-E. Trata-se de um DNA vírus de cadeia única, não-envelopado, pertencente à superfamília Circoviridae, com prevalência bastante variável em indivíduos saudáveis. Embora sua principal via de transmissão parece ser a parenteral, outras formas de transmissão não podem ser excluídas. Apesar da prevalência da infecção pelo SENV ser mais freqüente em pacientes com doenças hepáticas do que na população geral, não existem evidências comprovando que a infecção isolada por este vírus cause hepatite aguda ou que a co-infecção com os vírus das hepatites A, B ou C piore o curso da doença hepática. Em indivíduos com doença hepática preexistente não foram observadas diferenças estatisticamente significantes nos níveis de alanina aminotransferase (ALT) e nos achados histológicos hepáticos quando comparados os pacientes com e sem a infecção associada pelo vírus SEN. Diferente das infecções crônicas causadas pelos vírus B e C, a infecção pelo SENV não tem sido considerada como um fator de risco para o desenvolvimento de carcinoma hepatocelular. Finalmente, apesar da maior prevalência da infecção pelo vírus SEN em pacientes transfundidos, não existe evidência clara da relação causal entre este agente infeccioso e a hepatite pós-transfusional não A-E. Novos estudos são necessários para se definir a patogênese e a importãncia clínica da infecção pelo vírus SEN.SENV, a new, recently-identified human virus, has been considered a possible causative agent of non-A to E hepatitis. It is a single stranded, non-enveloped DNA virus classified within the Circoviridae family. Prevalence in different populations shows great variability with differences between countries and ethnic groups. Although parenteral route is an efficient way for virus transmission, other routes of transmission cannot be excluded. The effect of SENV on acute and chronic liver diseases has been studied. In spite of the fact that the prevalence of SENV is higher among patients with hepatic disorders, there is no evidence that SENV infection is able to cause acute hepatitis or to change the clinical course of hepatitis A, B or C. There is also no evidence that alanine aminotransferase (ALT) is higher or that the histological parameters are worse in patients with hepatic disorders co-infected with SENV as compared to patients without co-infections. Unlike chronic hepatitis B Virus or Hepatitis C Virus infection, SENV infection has not been considered a risk factor for developing hepatocellular carcinoma. Finally, although it is clear that the prevalence of SENV is higher in blood transfusion recipients, there is no clear evidence that this virus is the causative agent of post-transfusion hepatitis. Further studies are needed to define the clinical importance of SENV infection

External quality control program in infectious diseases screening at laboratories and blood banks in Latin America: an analysis of the past 5 years

Objective. To evaluate the screening of blood samples for infectious disease markers at laboratories and blood banks in Latin America per the findings of an External Quality Assessment Program (EQAP). Methods. This qualitative analysis used data from the EQAP coordinated by the Fundação Pro Sangue Hemocentro de São Paulo with the support of the Pan American Health Organization to assess the performance of blood screening for infectious diseases from 2014 to 2018 in Latin America. Each participating laboratory or blood bank received an identical blind panel with 24 blood samples with variable reactivity for all the screening parameters. Panels were processed at each participating facility and results were returned to the Fundação Pro Sangue Hemocentro de São Paulo for individual and joint analyses. Two types of discrepant results were potential failures: false positive results (FPRs) and false nonreactive results (FNRRs). Results. A total of 23 136 samples were evaluated. Global rates of FPR, FNRR, and concordant results were 0.3%, 1.0% and 98.7%, respectively. Seven FNRRs were found for HBsAg (1.0%), 12 for syphilis (2.6%), and 21 for Chagas disease (2.9%). No FNRRs were found for the HIV, HCV, and HTLV viruses. The average accuracy of all the laboratories and blood banks participating in the EQAP during the study period was 99.5% (standard deviation, 0.5%). Conclusion. The findings of this qualitative analysis are positive for blood safety in Latin America, with an average accuracy of 99.5% among the participating laboratories and blood banks. This report reflects an important improvement in blood bank serological screening EQAP-PAHO report since the 2003

The hidden Plasmodium malariae in blood donors: a risk coming from areas of low transmission of malaria

Malaria is an infectious vector-borne disease with other important routes of transmission, such as blood transfusion and organ/tissue transplantation, due to asymptomatic reservoirs of Plasmodium presenting with low parasitemia. Reports of transfusion-transmitted malaria have shown that in immunosuppressed recipients, infections can be fatal if they are not diagnosed and timely treated. All Plasmodium species can survive on blood components at temperatures from 2 to 6 °C for some days or even weeks. This report describes two candidates for blood donation harboring Plasmodium, infected in an area considered non-endemic. Blood samples were collected from donors who attended a blood bank in Sao Paulo and tested by microscopy, qPCR for Plasmodium genus-specific amplification, targeting the parasite 18S ribosomal subunit gene and a multiplex qPCR based on mtDNA of the five species. Under microscopy, only structures resembling Plasmodium were observed. The qPCR whose standard curve tested parasites varying from 2 to 0.1 parasites/ µL, showed the presence of Plasmodium DNA in the two blood donors, as did the multiplex qPCR that revealed the presence of P. malariae. The prevalence of positive donors varies according to the level of transmission, ranging from 0.7 to 55% in endemic areas. In non-endemic regions, prevalences are lower, however, transfusion malaria can evolve to severe cases, due to the lack of suspicion of this transmission route. Asymptomatic donors from low transmission regions pose a risk to blood banks, with particular emphasis on those located in areas with malaria elimination goals

Profile of blood donors with serologic tests reactive for the presence of syphilis in São Paulo, Brazil.

BackgroundSyphilis screening of blood donors is a common practice worldwide, but very little is known about the meaning of a positive serologic test for syphilis in blood donors and the risk profile of these donors. The aim of this study was to determine the demographic characteristics and risk behaviors of blood donors with recent and past syphilis and their implications for blood bank testing and deferral strategies.Study design and methodsDemographic characteristics, category of donation, number of previous donations, sexual behavior, and history of sexually transmitted diseases were reviewed comparing blood donors with recent and past syphilis from January 1, 1999, to December 31, 2003.ResultsA total of 2439 interviews were reviewed, including 2161 (88.6%) donors with past and 278 (11.4%) with recent syphilis infection. Factors associated with recent infection included younger age (&lt; or = 20 years odds ratio [OR], 36.5; 95% confidence interval [CI], 15.8-84.1), two previous donations (OR, 2.7; 95% CI, 1.9-3.9), male-male sex (homosexual OR, 8.2; 95% CI, 3.2-20.8; and bisexual OR, 11.4; 95% CI, 3.6-36.3), two or more partners in the past 12 months (OR, 2.3; 95% CI, 1.3-4.0), symptoms for syphilis (OR, 4.5; 95% CI, 2.8-7.1), and human immunodeficiency virus (HIV) seropositivity (OR, 39.6; 95% CI, 4.6-339.8). Community donors were also associated with recent syphilis infection (OR, 1.5; 95% CI, 1.2-1.9) compared to replacement donors.ConclusionSexual history, including male-male sex and multiple partners, were strongly associated with recent syphilis infection, which in turn was strongly associated with HIV. Continuous and vigilant surveillance that includes assessing sexual history and other factors associated with syphilis are needed to guide blood safety policies

Are different motivations and social capital score associated with return behaviour among Brazilian voluntary non‐remunerated blood donors?

BACKGROUND: We examined the association between social capital score, motivator factors and demographic and donation characteristics and donor return at three Brazilian blood centres in Recife, São Paulo and Belo Horizonte. MATERIAL AND METHODS: A total of 5974 donors were interviewed about motivation factors to donate and cognitive and structural social capital just before an effective donation in three Brazilians blood centres in 2009. We assessed the return to a new donation within 2 years for each of these donors. Demographic and donation characteristics, motivators and scores of social capital and their association with donors return were assessed. RESULTS: Overall, 3123 (52.3%) of the study subjects returned for a blood donation at least once. Predictors of donors return were male gender (adjusted odds ratio [AOR] = 1.6, 1.3-1.9, for replacement and AOR = 1.3, 1.2-1.6, for community donors), previous donation (AOR = 2.7, 2.3-3.3, for replacement and AOR = 2.9, 2.5-3.5, for community donors) and high altruism (AOR = 1.3, 1.1-1.7, for replacement and AOR = 1.2, 1.0-1.5, for community donors). Altruism was the only motivator associated with return behaviour. Donors from Recife and São Paulo were more likely to return for replacement and/or for community donations than donors from Belo Horizonte. There was no association between social capital score and donor return behaviour. CONCLUSION: The likelihood to return for a subsequent blood donation is dependent upon characteristics of individual donors and also varies in different regions of Brazil. However, social capital was not associated with the likelihood of return behaviour. A better understanding of altruistic categories and appeals may help to improve donor recruitment and retention