RESUMO
Drug development (DD) is a multidisciplinary process that spans the translational continuum, yet remains an understudied entity in medical schools and biomedical science institutes. In response to a growing interest and unmet need, we implemented a DD course series that details identification of viable molecular targets, clinical trial design, intellectual property, and marketing. Enrollment is open to faculty, postdoctoral trainees, and MD, PhD, and MS students. After 2 years, 37 students and 23 students completed the fall and spring courses, respectively. Pre/post-surveys demonstrated gained knowledge across course topics, with mean survey scores increased by 66% (p < 0.001) after each course. Lectures for each course were consistently rated highly, with a mean course rating of 4.1/5. Through this program, trainees will have a more innovative approach toward identification of therapeutic targets and modalities. Furthermore, they will learn to integrate technology and biomedical informatics to find creative solutions in the DD process.
RESUMO
The prevalence of autism spectrum disorders (ASDs) has increased 20-fold over the past 50 years to >1% of US children. Although twin studies attest to a high degree of heritability, the genetic risk factors are still poorly understood. We analyzed data from two independent populations using u-statistics for genetically structured wide-locus data and added data from unrelated controls to explore epistasis. To account for systematic, but disease-unrelated differences in (non-randomized) genome-wide association studies (GWAS), a correlation between P-values and minor allele frequency with low granularity data and for conducting multiple tests in overlapping genetic regions, we present a novel study-specific criterion for 'genome-wide significance'. From recent results in a comorbid disease, childhood absence epilepsy, we had hypothesized that axonal guidance and calcium signaling are involved in autism as well. Enrichment of the results in both studies with related genes confirms this hypothesis. Additional ASD-specific variations identified in this study suggest protracted growth factor signaling as causing more severe forms of ASD. Another cluster of related genes suggests chloride and potassium ion channels as additional ASD-specific drug targets. The involvement of growth factors suggests the time of accelerated neuronal growth and pruning at 9-24 months of age as the period during which treatment with ion channel modulators would be most effective in preventing progression to more severe forms of autism. By extension, the same computational biostatistics approach could yield profound insights into the etiology of many common diseases from the genetic data collected over the last decade.
Assuntos
Bioestatística/métodos , Transtornos Globais do Desenvolvimento Infantil/genética , Estudo de Associação Genômica Ampla/métodos , Receptores de Fatores de Crescimento/genética , Índice de Gravidade de Doença , Transdução de Sinais/genética , Canais de Cálcio/genética , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla/estatística & dados numéricos , Humanos , Masculino , Ácido Mefenâmico , Moduladores de Transporte de Membrana , Canais de Potássio/genéticaRESUMO
Meckel-Gruber syndrome (MKS) is an autosomal recessive disorder causing severe defects in the developing central nervous system and other organs. Recently, mutations in the MKS1 gene have been identified as disease causing in individuals of Finnish MKS families. The primary aim of the present study was to assess the frequency of the 'Finnish founder mutation' (29 bp IVS15-7_35) in the MKS1 gene in 20 aborted fetuses with a diagnosis of MKS. The secondary aim was to screen for novel mutations in the coding sequence of the MKS1 gene of MKS fetuses and to obtain genotype-phenotype correlations where possible. Furthermore, we evaluated the carrier rate of a deletion of 29 bp in intron 15 of the MKS1 gene in a German population. To identify and characterize mutations in the MKS1 gene, sequence analyses and quantitative real time polymerase chain reaction studies were performed. We could identify the same type of mutation, a deletion of 29 bp in intron 15 of the MKS1 gene, in 8 out of the 20 cases studied. Six out of the eight cases with such a mutation displayed the campomelic variant of MKS. The carrier frequency among 519 healthy German individuals was 1:260. This deletion in the MKS1 gene is highly associated with a distinct subtype of the MKS, namely the campomelic variant. In individuals of European origin suffering from the campomelic MKS variant, the described deletion is highly likely to be causative. Regarding the results of our study, the incidence of MKS in Germany can be estimated as 1:135,000. In families with a known mutation in the MKS1 gene, it is now possible to offer an early prenatal testing, for example with chorionic villus sampling and mutation analysis.
Assuntos
Anormalidades Múltiplas/genética , Sistema Nervoso Central/anormalidades , Íntrons , Polidactilia/genética , Proteínas/genética , Deleção de Sequência , Feto Abortado/diagnóstico por imagem , Sequência de Bases , Análise Mutacional de DNA , Feminino , Frequência do Gene , Testes Genéticos , Humanos , Masculino , Dados de Sequência Molecular , Radiografia , SíndromeRESUMO
BACKGROUND: Virus inactivation of plasma can be achieved by photodynamic methods in the presence of phenothiazine dyes such as methylene blue (MB). Subsequent filtration may increase the efficacy of virus inactivation and reduce adverse effects of WBC contamination and MB. STUDY DESIGN AND METHODS: This study examined the effect of filtration with three different filters (MBF1, MBF2, and MBF3) on MB concentration, residual cells, coagulation factors, and activation measures of coagulation, fibrinolysis, and complement in MB-treated (1 microM/L) plasma units. RESULTS: Filtration reduced the concentration of MB by > or = 89 percent. WBCs were depleted by 92 percent (MBF1) and >99.9 percent (MBF2 and MBF3). Treatment with MB significantly decreased the coagulation potency from levels in untreated plasma, as measured by thromboplastin time ratio (112 +/- 18% vs. 95 +/- 11%), activated partial thromboplastin time (40 +/- 3 sec vs. 44 +/- 3 sec), thrombin time (16.9 +/- 1.1 sec vs. 18.6 +/- 1.5 sec), factor VIII (1.09 +/- 0.21 U/mL vs. 0.85 +/- 0.13 U/mL), and vWF (0.94 +/- 0.65 U/mL vs. 0.65 +/- 0.24 U/mL). Filtration did not further decrease these values, while factor XI (0.75 +/- 0.22 U/mL vs. 0.37 +/- 0.20 U/mL) and prekallikrein values decreased in MB plasma units filtered with the MBF3. In addition, activated factor XII (0.7 +/- 0.5 microg/L vs. 4.5 +/- 1.0 microg/L) increased. CONCLUSION: WBCs and MB can be eliminated from MB-treated plasma units by filtration. Differences in biocompatibility of the different filters, especially the influence on the contact phase of coagulation, must be taken into consideration.
Assuntos
Hemofiltração , Luz , Azul de Metileno/farmacologia , Plasma/metabolismo , Coagulação Sanguínea/efeitos dos fármacos , Coagulação Sanguínea/fisiologia , Complexo de Ataque à Membrana do Sistema Complemento , Proteínas do Sistema Complemento , Contagem de Eritrócitos , Glicoproteínas/sangue , Humanos , Contagem de Leucócitos , Azul de Metileno/análise , Concentração Osmolar , Oxirredução/efeitos da radiação , Tempo de Tromboplastina Parcial , Plasma/citologia , Plasma/fisiologia , Plasma/efeitos da radiação , Fator Plaquetário 4/análiseRESUMO
BACKGROUND: To allow cost-effective RNA testing with NAT techniques, the national authorities of several countries have planned or already introduced tests of mixed specimens, that is, plasma pools. STUDY DESIGN AND METHODS: High-throughput extraction, amplification, and detection of HCV RNA from individual blood donations were optimized and validated. The feasibility of the method and the frequency of anti-HCV-negative, HCV RNA-positive donations were determined in a prospective study of 27,745 allogeneic and 792 autologous individual donations. RESULTS: The 50- and 95-percent detection limits of the method were determined at 44 IU per mL and 162 IU per mL, respectively (World Health Organization HCV reference material). When 201 HCV RNA-positive sera were taken as a reference, the sensitivity was 97.5 percent. The assay specificity was determined at 99.77 percent. During a 20-month period, two seronegative blood donors tested positive in HCV PCR. The viral load of these donations was 6 x 10(6) and 3 x 10(7) copies per mL, respectively. Thus, the yield of HCV RNA testing in this study was 7. 63 per 100,000 screened donations (95% CI, 1.25-22.07). In both PCR-positive donors, seroconversion was found in subsequent blood samples. CONCLUSION: This study compares the feasibility of single-donation HCV RNA screening, with the detection of a relatively high percentage of window-phase donations, to data reported from groups using HCV RNA testing of plasma pools. The relative yield of NAT of individual donations versus minipools should be directly investigated in the near future.
Assuntos
Doadores de Sangue , Hepacivirus/genética , RNA Viral/sangue , Reação Transfusional , Reações Falso-Positivas , Hepatite C/epidemiologia , Hepatite C/transmissão , Humanos , Reprodutibilidade dos Testes , Fatores de Risco , Sensibilidade e EspecificidadeRESUMO
Detection of two different cell populations in a child is a rare event. The following case of a dispermic chimera was diagnosed before surgery due to problems in blood group determination. A 2-year-old phenotypically male child was admitted for correction of a penoscrotal hypospadia and unilateral cryptorchism. During presurgical laboratory investigation, difficulties in blood group determination occurred. Blood group typing was performed by the DiaMed-ID Micro Typing System and by FACS. Additionally, cytogenetic analysis of lymphocytes and analysis of DNA polymorphisms in different tissues were performed. Two populations of red blood cells were detected, O cells accounting for 75% and B cells for 25%. Analysis of DNA-PCR polymorphisms in lymphocytes, nails, and in cells of the oral mucous membrane demonstrated a chimerism, with two alleles inherited from the father and one from the mother. A cytogenetic analysis of cultured lymphocytes showed a mosaic 46, XY/46,XX. Surgery revealed a prostatic utricle grade III, also called pseudovagina; genitography confirmed a vagina. Bilateral gonad biopsy showed a testis on one side and an ovary on the other. This case of chimerism represents a true hermaphroditism that most probably developed by double fertilization of one or more egg nuclei by two sperms.
Assuntos
Quimera , Transtornos do Desenvolvimento Sexual/genética , Tipagem e Reações Cruzadas Sanguíneas , Pré-Escolar , Genitália Masculina/anormalidades , Humanos , Masculino , FenótipoRESUMO
OBJECTIVES: Contaminating white blood cells (WBC) in apheresis platelet concentrates (PC) can cause a variety of adverse effects after platelet transfusion. To obtain PCs with low WBC contamination, a new leukoreduction system (LRS) utilizing 'fluidized particle bed' technology has recently been introduced. METHODS: We prospectively examined the effect of LRS apheresis on the donor, the quality of the resulting PCs (n = 120), and the platelet increment in the corresponding recipients. Conventionally prepared apheresis PCs served as control group (n = 27). Platelet glycoproteins were examined by flow cytometry. RESULTS: In LRS apheresis, we observed no serious adverse effects on the donors, but the postdonation absolute lymphocyte counts were reduced from 1,787 +/- 505/microliter to 1,405 +/- 383/microliter (p < 0.001). Comparable results were seen in non-LRS donors. The collection efficiency of the LRS procedures was 50.0 +/- 7.6%, resulting in a yield of 4.3 +/- 1.0 x 10(11) platelets/PC. In flow cytometry, platelet glycoproteins in LRS PCs were not elevated: mean fluorescence of CD62 (6 +/- 4) or CD63 (9 +/- 3) in comparison with non-LRS PCs (mean fluorescence of CD62: 7 +/- 4, CD63: 8 +/- 3). Median leukocyte contamination of the LRS PCs was 0.41 x 10(5) (range 0.07-8.5) WBCs/unit. In 43 recipients, the 24-hour corrected count increments after transfusion of LRS PCs (12,530 +/- 8,761) were essentially the same as those of 20 recipients of non-LRS PCs (13,133 +/- 9,812; p = 0.75). CONCLUSIONS: LRS apheresis appears to be a safe procedure, which produced effective PCs with few contaminating leukocytes. With new apheresis technology, filtration of PCs may become superfluous.
Assuntos
Depleção Linfocítica , Transfusão de Plaquetas/efeitos adversos , Plaquetoferese/métodos , Antígenos de Plaquetas Humanas/análise , Doadores de Sangue , Centrifugação , Estudos de Avaliação como Assunto , Citometria de Fluxo , Humanos , Contagem de Linfócitos , Subpopulações de Linfócitos , Plaquetoferese/instrumentação , Estudos Prospectivos , SegurançaRESUMO
The use of leukocyte-depleted blood components has become the standard therapy for multiply transfused patients during the past few years, as a measure to reduce the frequency of alloimmunization and refractoriness. We assessed frequency and causes of refractoriness, defined as a repeated 24-h post-transfusion platelet count below 20,000/microliters, in 145 consecutive patients who received three or more single-donor platelet concentrates during a 1-year period. Flow-cytometric detection of anti-platelet antibodies and a glycoprotein-specific ELISA were applied for the diagnosis of alloimmunization. Forty patients (27.6%) had at least one episode of refractoriness. In 25 of these 40 patients (62.5%), nonimmune factors (fever, sepsis, coagulopathy, splenomegaly) alone were the cause. In 15 refractory patients alloantibodies were detected. In seven patients (17.5%), alloimmunization alone caused an inadequate transfusion response, while in eight refractory patients (20.0%) alloimmunization and fever or sepsis were present. HLA antibodies were detected in 17 patients (11.7%); three patients (2%) had platelet-specific antibodies in addition to HLA antibodies; in two patients panreactive platelet antibodies were detectable. All 17 patients had a history of previous transfusions or pregnancy. We did not observe primary immunization in patients transfused exclusively with filtered (leukodepleted) blood products. Our data suggest that alloimmunization in patients with a negative risk history can be prevented by the exclusive use of leukodepleted blood components.
Assuntos
Isoanticorpos/análise , Transfusão de Plaquetas , Antígenos de Plaquetas Humanas/imunologia , Feminino , Citometria de Fluxo , Antígenos HLA/imunologia , Humanos , Imunoglobulina G/imunologia , Leucaférese , MasculinoRESUMO
Passenger white blood cells (WBC) in platelet concentrates (PC) produced by apheresis can cause a variety of adverse effects in recipients after platelet transfusion. With new technologies (LRS, leukocyte reduction system), the preparation of PC with a low WBC contamination is possible without consecutive filtration. In a prospective examination, we compared the effect of LRS apheresis on the donor, the quality of the resulting PC (n = 120), and the platelet increment in the corresponding recipients with conventionally prepared PC (n = 27). In LSR apheresis, no serious adverse effects on the donors were observed, but the post-donation absolute numbers of lymphocytes were reduced from 1,787 +/- 505/microliter to 1,402 +/- 383/microliter (p < 0.001). Comparable results were observed in non-LRS donors. The collection efficiency of the LRS procedures was 50.0 +/- 7.6%, resulting in a yield of 4.25 +/- 1.03 x 10(11) platelets/PC. Flow cytometric examination concerning the expression of platelet glycoproteins in LRS PC showed no elevation in mean fluorescence of CD 62 (6 +/- 4) or CD 63 (9 +/- 3) in comparison to non-LRS PC (mean fluorescence CD 62: 7 +/- 4, CD 63: 8 +/- 3). Median leukocyte contamination of the LRS PC was 0.41 x 10(5) (range 0.06-8.5 x 10(5)) WBC/unit. In 43 recipients, the 24-hour corrected count increments (CCI) after transfusion of LRS PC (12,530 +/- 8,761) showed no significant differences when compared with the CCI in 20 recipients of non-LRS PC (13,133 +/- 9,812, p = 0.75). LRS apheresis seems to be safe procedure, resulting in PC with low WBC contamination, which causes adequate CCI values after transfusion.
Assuntos
Contagem de Linfócitos , Plaquetoferese , Adulto , Doadores de Sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Controle de QualidadeRESUMO
In order to estimate the residual risk of transfusion-transmitted HCV infection, we have analyzed data from transfusion centers in Austria (Vienna) and Germany (Göttingen) from 1990 to 1995. In Vienna, the seroprevalence (RIBA-confirmed third-generation anti-HCV tests) was 0.28% in first-time donors (FTD) and the incidence of seroconversion in repeat donors (RD) was 0.049 (per 100 person years) from 1994 to 1995. In Göttingen, the prevalence of a PCR-confirmed positive third-generation anti-HCV test was 0.22% in FTDs and the incidence was 0.093 (per 100 persons years). A continuous decline of the rate of anti-HCV-positive donations and donors was observed with first- and second-generation anti-HCV tests in the years 1990-1994. The introduction of the third-generation anti-HCV test resulted in increased numbers of anti-HCV positive repeat donors, mainly due to false-positive results. Only 9% of anti-HCV-positive repeat donors were either PCR positive or RIBA positive or or indeterminate. Based on a mathematical model which takes (a) the window period, (b) the false-negative rate of anti-HCV tests, and (c) human and operational errors into consideration, we have calculated the residual risk of HCV infection. We used a window period of 74 days, a sensitivity of 98%, and an error rate of .1%. The residual risk (for third-generation anti-HCV test-negative blood components) was calculated to be 1:9000 (95% confidence interval 1:16390-1:6210) and 1:4800 (95% confidence interval 1:40000-1:1320) for Vienna and Göttingen, respectively, in 1994 and 1995. Since this conservative approach does not take the impact of ALAT screening into account, the actual risk is probably lower.
Assuntos
Hepacivirus/isolamento & purificação , Hepatite C/transmissão , Reação Transfusional , Adulto , Áustria , Doadores de Sangue , Reações Falso-Positivas , Alemanha , Humanos , Fatores de RiscoRESUMO
The effects of blood transfusion and blood donation on the immune system are still unclear. In a prospective study we investigated the effect of blood and blood component donation on several immunologic parameters. Lymphocyte subsets and cytokine levels were determined in 25 repeat whole-blood donors (RD), 25 plateletpheresis donors (PD), and 20 autologous blood donors (AD). First-time donors (FTD, n = 20) served as controls. Lymphocyte subsets and cytokines were determined using standard methods. Leukocytes, T-suppressor cells and natural killer (NK) cells were decreased in RD and PD when compared to FTD. Additionally, NK cells decreased with repeat donations in AD. No significant differences of cytokines in the different groups or during repeat autologous donations were observed.
Assuntos
Formação de Anticorpos/imunologia , Doadores de Sangue , Imunidade Celular/imunologia , Adulto , Subpopulações de Linfócitos B/imunologia , Citocinas/sangue , Feminino , Humanos , Tolerância Imunológica/imunologia , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Subpopulações de Linfócitos T/imunologiaRESUMO
In order to estimate the residual risk of transfusion-transmitted HIV infection we have analyzed the data from two transfusion centers in Austria (Vienna) and Germany (Göttingen) from 1985 to 1994. In Vienna, an incidence of 1:42,000 positive anti-HIV tests in repeat donors and a prevalence of 1:7000 in first-time donors were found in 1993. In Göttingen, the indicence was 1:67,000 and the prevalence 1:7900 from 1985 to 1993. Based on a mathematical model which takes (a) the window period and (b) the false-negative rate of anti-HIV tests, as well as (c) human and operational errors into consideration, we have calculated the residual risk of HIV infection. The residual risk (third generation anti-HIV test) was found to be 1:520,000 (95% confidence interval 1:1340,000-1:210,000), and 1:900,000 (95% confidence interval 1:2340,000-1:380,000) for Vienna and Göttingen, respectively, in 1993. Look-back studies from 1985 till 1994 revealed transfusion-transmitted HIV infections in three recipients (for 1.9 million donations in Vienna) and one recipient (for 160,000 donations in Göttingen) of blood components. Based on our model, as well as on prevalence and incidence rates of HIV infection, it is also possible to predict the efficacy of additional measures introduced to further decrease the risk of transfusion-transmitted HIV infection through blood components.
Assuntos
Doadores de Sangue , Infecções por HIV/transmissão , Soronegatividade para HIV , Reação Transfusional , Áustria , Alemanha , Anticorpos Anti-HIV/sangue , Infecções por HIV/epidemiologia , Humanos , Fatores de RiscoRESUMO
In-line filtration of blood components appears to be an effective method to reduce white-cell-induced adverse reactions. We have investigated whether whole blood filtration (WBF), prior to component preparation, is comparable with filtration of already prepared blood components (CF), i.e. the red cell concentrate (RCC) and fresh plasma. Conventionally prepared nonfiltered blood components served as a control. No significant differences for most parameters investigated were found between leukodepleted RCCs and plasma units prepared by CF or WBF. All filtered RCCs and plasma units (CF and WBF) had white blood cell contaminations < 1 x 10(5) per unit. Platelets were reduced in all filtered components: 95% in plasma and 99% in RCCs. Fresh-frozen plasma (FFP) prepared by CF and WBF had normal amounts of factors V, VIII, von Willebrand factor and thrombin-antithrombin-III complexes, whereas platelet factor 4 (PF-4) was slightly increased in FFP prepared by WBF. RCCs and plasma units prepared from filtered whole blood (n = 20) had a significantly greater volume (RCC: 288 +/- 19 ml; plasma: 274 +/- 20 ml) than conventionally prepared (n = 20) and filtered products (RCC: 257 +/- 19 ml, plasma: 259 +/- 19 ml). For early filtration of blood components, WBF prior to component preparation seems to offer an interesting technique for obtaining a leukocyte-depleted RCC and FFP.
Assuntos
Remoção de Componentes Sanguíneos , Preservação de Sangue , Contagem de Leucócitos , Contagem de Células Sanguíneas , Estudos de Viabilidade , Filtração , Humanos , Estudos ProspectivosRESUMO
We report on flow cytometric IgG subclass determinations of red cell antibodies using polyclonal FITC-labeled antibodies. The limit of detection of this method was 1 ng anti-D per 1 x 10(7) red cells. The inter- and intra-assay coefficients of variance were 8.2 and 2.3%, respectively. In 8 newborns with a positive direct antiglobulin test (DAT) in the gel centrifugation test (GCT), due to ABO antibodies, IgG1 was detected in all and IgG2 additionally in 4 of these cases. In 5 severe cases of hemolytic disease of the newborn (HDN) due to anti-D, large amounts of IgG1 were found, and in 3 of these 5, IgG3 in combination with IgG1. In 8 mild or moderate HDN cases (4 anti-D, 2 anti-E, 1 anti-Fya, 1 anti-Jka), phototherapy sufficed, and IgG1 was the only antibody. In 7 adult patients with malignant lymphoma and a positive DAT (GCT), only small amounts of IgG1 red cell autoantibodies could be demonstrated by flow cytometry. In 5 further patients with malignant lymphoma, a positive DAT, and severe hemolytic anemia, large amounts of IgG1 autoantibodies were found and IgG3 was also present in 3 of these cases. Flow-cytometric determination of IgG subclasses may be a useful tool in immunohematology, since subclass determinations were possible in all of these cases. This method is suited for clinical routine and offers the possibility of sufficient standardization.
Assuntos
Autoanticorpos/sangue , Antígenos de Grupos Sanguíneos/imunologia , Eritroblastose Fetal/imunologia , Eritrócitos/imunologia , Citometria de Fluxo , Imunoglobulina G/classificação , Isoanticorpos/classificação , Adulto , Anemia Hemolítica/sangue , Anemia Hemolítica/diagnóstico , Anemia Hemolítica/etiologia , Anemia Hemolítica/imunologia , Teste de Coombs , Eritroblastose Fetal/sangue , Eritroblastose Fetal/diagnóstico , Eritroblastose Fetal/terapia , Transfusão Total , Feminino , Morte Fetal/etiologia , Humanos , Imunoglobulina G/sangue , Recém-Nascido , Isoanticorpos/sangue , Linfoma/complicações , Fototerapia , Gravidez , Complicações na Gravidez/sangue , Complicações na Gravidez/imunologia , Isoimunização Rh/sangue , Isoimunização Rh/imunologia , Índice de Gravidade de DoençaRESUMO
Prophylaxis of infection and alloimmunisation is the main reason for leucocyte depletion by filtration of blood components. The question is whether all red cell concentrates (RCC) should be filtered and whether plasma has to be filtered, too. For leucocyte-poor units whole blood was filtered before preparation using the 'top and bottom' system. These units of buffy-coat-poor RCC and plasma were compared with components filtered after preparation. Non-filtered RCCs and plasmas served as a control. By prefiltration of whole blood and filtration of components we obtained RCCs and plasmas with less than 1 x 10(5) leucocytes in every unit. In conclusion, leucocyte filtration before preparation seems to be an easy and cost-effective method in order to get two filtered components (RCC and plasma) with one filter.
Assuntos
Citaferese/métodos , Eritrócitos , Transfusão de Componentes Sanguíneos , Filtração/métodos , Humanos , LeucócitosRESUMO
Red cell IgG antibodies capable of causing hemolytic disease of the newborn (HDN) or autoimmune hemolytic anemia (AIHA) have been analyzed concerning their IgG subclasses using flow cytometry. The results were always in agreement with those of the direct Coombs test. Anti-A and/or anti-B able to cause HDN belonged to the IgG1 subclass (4/8 cases) or to the subclasses IgG1 and IgG2 (4/8 cases). In 3 out of 4 cases of HDN caused by Rh antibodies the antibodies belonged to the subclasses IgG1 and IgG3. In patients with lymphoma but without AIHA, red cell autoantibodies were often found to be IgG1 only (n = 10), in low concentrations. In cases of acute AIHA in adults caused by IgG autoantibodies the subclass IgG3 was found in addition to IgG1 in 4/5 cases. In our opinion flow cytometry should become substantial for immunohematological diagnostics.
Assuntos
Anemia Hemolítica Autoimune/imunologia , Anemia Hemolítica Congênita/imunologia , Autoanticorpos/sangue , Eritrócitos/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/classificação , Isoanticorpos/sangue , Adulto , Anemia Hemolítica Autoimune/sangue , Anemia Hemolítica Congênita/sangue , Teste de Coombs , Citometria de Fluxo/métodos , Humanos , Recém-Nascido , Linfoma/sangue , Linfoma/imunologiaRESUMO
Membrane glycoprotein (GP) expression on platelets changes during preparation of concentrates and storage. Recent studies proved that the increased expression of the GMP-140 (CD 62), a GP appearing on platelets after activation, correlates with the in vivo recovery of transfused platelets. We therefore investigated the expression of this and three other GP (GP IIb/IIIa, GP, Ib, GP 53), detected by flow cytometry, in normal controls and in platelet concentrates prepared by four different methods (apheresis, preparation from buffy coat, from pooled buffy coat and platelet-rich plasma) after preparation and during storage. Furthermore we investigated the influence of filtration, radiation and washing platelet concentrates on the expression of GP. The results can be summarized as follows: (1) The mean surface fluorescence (MF) is a better parameter for the evaluation of preparation and storage lesions than the total number of positive cells. (2) The mean fluorescence of GP Ib in platelet concentrates is generally lower than in normal controls and decreases continuously during storage; there is a small loss of GP Ib through washing and filtration. (3) GP IIb/IIIa fluctuates during preparation and storage, therefore it is not suitable for evaluation of quality. (4) The percentage of CD 62 positive cells and their mean fluorescence is higher in platelet concentrates than in normal controls and increases during storage continuously. There is a weak correlation of CD 62 with CD 63. (5) The changes of GP in apheresis concentrates and concentrates obtained from whole blood are similar after preparation and during storage.
Assuntos
Plaquetas , Preservação de Sangue , Glicoproteínas da Membrana de Plaquetas/análise , Plaquetoferese , Plaquetas/química , Citometria de Fluxo , Humanos , Selectina-P/sangue , Ativação Plaquetária , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/análise , Complexo Glicoproteico GPIb-IX de Plaquetas/análise , Valores de ReferênciaRESUMO
We report the first results of a prospective study concerning antibody screening in transfusion recipients. We compared the standard tube test (Liss Coombs) with two commercial tests for the detection of red cell IgG antibodies: (1) a column/agglutination test and (2) a microplate/solid-phase system. The results of the study demonstrate several significant advantages of the two methods as compared with the standard tube test. The new methods, especially the microplate test, are superior in determining red cell antibodies which are relevant to transfusion. The two methods are more sensitive and, when automated, more efficient and safer as compared with the standard tube test.
Assuntos
Tipagem e Reações Cruzadas Sanguíneas/instrumentação , Transfusão de Sangue , Teste de Coombs/instrumentação , Testes de Hemaglutinação/instrumentação , Imunoglobulina G/análise , Isoanticorpos/análise , Processamento de Sinais Assistido por Computador/instrumentação , Eritrócitos/imunologia , Humanos , Valor Preditivo dos Testes , Estudos ProspectivosRESUMO
Platelets of healthy smokers and non-smokers were prepared and their content of 5-hydroxytryptamine was determined by HPLC with electrochemical detection. Platelet 5-HT levels in smokers (728 +/- 156 pmol per 10(8) platelets, mean +/- SEM, n = 9) were significantly higher than those in non-smokers (353 +/- 156 pmol per 10(8) platelets, n = 11). Smoking of a single cigarette caused a transient increase in platelet 5-HT levels by about 350% in non-smokers, but had no additional effect in smokers. Similarly, chewing of nicotine gum (4-8 mg nicotine) resulted in a transient increase in platelet 5-HT by about 100% in non-smokers, but not in smokers. In conclusion, smoking of cigarettes can cause an increase in platelet 5-HT, most likely via an enhanced supply of 5-HT from enterochromaffin cells which can be stimulated via nicotine receptors.
Assuntos
Plaquetas/química , Nicotina/farmacologia , Serotonina/sangue , Fumar , Administração Oral , Adulto , Plaquetas/metabolismo , Células Enterocromafins/metabolismo , Humanos , Nicotina/administração & dosagem , Receptores Nicotínicos/efeitos dos fármacos , Receptores Nicotínicos/fisiologia , Receptores de Serotonina/metabolismo , Serotonina/metabolismoRESUMO
The need of fresh-frozen donor plasma with a low level of anti-T has been emphasized recently. Anti-T, as administered by transfusion of fresh-frozen plasma, has been accused repeatedly of enhancing hemolysis in septic children with T transformation of red cells. Therefore, a new hemolysis test for the quantification of anti-T in human serum has been developed. With our test, anti-T-poor plasma donors can be found. Additional results raise substantial doubt as to the pathogenetic role of anti-T in the development of the hemolytic-uremic syndrome, found in septic children with red-cell T transformation. It is impossible to predict in vivo hemolysis induced by anti-T knowing the temperature characteristics and the ionic conditions causing this antibody to mediate hemolysis in vitro. Obviously, T transformation itself plays the major pathogenetic role in these patients, and not the presence of anti-T. In the case of disseminated intravascular coagulation, a content of anti-T cannot be construed as prohibiting transfusion of fresh-frozen plasma to such patients.