Generation of a novel model of bioengineered human oral mucosa with increased vascularization potential.

OBJECTIVE: The aim of this study was to generate novel models of bioartificial human oral mucosa with increased vascularization potential for future use as an advanced therapies medicinal product, by using different vascular and mesenchymal stem cell sources. BACKGROUND: Oral mucosa substitutes could contribute to the clinical treatment of complex diseases affecting the oral cavity. Although several models of artificial oral mucosa have been described, biointegration is a major issue that could be favored by the generation of novel substitutes with increased vascularization potential once grafted in vivo. METHODS: Three types of mesenchymal stem cells (MSCs) were obtained from adipose tissue, bone marrow, and dental pulp, and their in vitro potential was evaluated by inducing differentiation to the endothelial lineage using conditioning media. Then, 3D models of human artificial oral mucosa were generated using biocompatible fibrin-agarose biomaterials combined with human oral mucosa fibroblasts and each type of MSC before and after induction to the endothelial lineage, using human umbilical vein endothelial cells (HUVEC) as controls. The vascularization potential of each oral mucosa substitute was assessed in vitro and in vivo in nude mice. RESULTS: In vitro induction of MSCs kept in culture was able to increase the expression of VEGF, CD31, and vWF endothelial markers, especially in bone marrow and dental pulp-MSCs, and numerous proteins with a role in vasculogenesis become overexpressed. Then, in vivo grafting resulted in a significant increase in blood vessels formation at the interface area between the graft and the host tissues, with significantly positive expression of VEGF, CD31, vWF, and CD34 as compared to negative controls, especially when pre-differentiated MSCs derived from bone marrow and dental pulp were used. In addition, a significantly higher number of cells committed to the endothelial lineage expressing the same endothelial markers were found within the bioartificial tissue. CONCLUSION: Our results suggest that the use of pre-differentiated MSCs could contribute to a rapid generation of a vascular network that may favor in vivo biointegration of bioengineered human oral mucosa substitutes.

SARS-CoV-2 neutralising antibody testing in Europe: towards harmonisation of neutralising antibody titres for better use of convalescent plasma and comparability of trial data.

We compared the performance of SARS-CoV-2 neutralising antibody testing between 12 European laboratories involved in convalescent plasma trials. Raw titres differed almost 100-fold differences between laboratories when blind-testing 15 plasma samples. Calibration of titres in relation to the reference reagent and standard curve obtained by testing a dilution series reduced the inter-laboratory variability ca 10-fold. The harmonisation of neutralising antibody quantification is a vital step towards determining the protective and therapeutic levels of neutralising antibodies.

Unprecedented increase of West Nile virus neuroinvasive disease, Spain, summer 2020.

Cases of West Nile neuroinvasive disease (WNND) in Spain increased in summer 2020. Here we report on this increase and the local, regional and national public health measures taken in response. We analysed data from regional surveillance networks and the National Epidemiological Surveillance Network, both for human and animal West Nile virus (WNV) infection. During the 2020 season, a total of 77 human cases of WNV infection (median age 65 years; 60% males) were detected in the south-west of Spain; 72 (94%) of these cases developed WNND, presenting as meningoencephalitis, seven of which were fatal. In the previous two decades, only six human cases of WNND were detected in Spain. Reduced activities for vector control this season, together with other factors, might have contributed to the massive increase. Public health measures including vector control, campaigns to raise awareness among physicians and the general population, and interventions to ensure the safety of donations of blood products, organs, cells and tissues were effective to reduce transmission. Going forward, maintenance of vector control activities and an update of the vector-borne diseases response plan in Spain is needed.

West Nile and Usutu Virus Infections and Challenges to Blood Safety in the European Union.

West Nile virus (WNV) and Usutu virus (USUV) circulate in several European Union (EU) countries. The risk of transfusion-transmitted West Nile virus (TT-WNV) has been recognized, and preventive blood safety measures have been implemented. We summarized the applied interventions in the EU countries and assessed the safety of the blood supply by compiling data on WNV positivity among blood donors and on reported TT-WNV cases. The paucity of reported TT-WNV infections and the screening results suggest that blood safety interventions are effective. However, limited circulation of WNV in the EU and presumed underrecognition or underreporting of TT-WNV cases contribute to the present situation. Because of cross-reactivity between genetically related flaviviruses in the automated nucleic acid test systems, USUV-positive blood donations are found during routine WNV screening. The clinical relevance of USUV infection in humans and the risk of USUV to blood safety are unknown.

Cell-based product classification procedure: What can be done differently to improve decisions on borderline products?

In June 2015, European Medicines Agency/Committee for Advanced Therapies (CAT) released the new version of the reflection paper on classification of advanced therapy medicinal products (ATMPs) established to address questions of borderline cases in which classification of a product based on genes, cells or tissues is unclear. The paper shows CAT's understanding of substantial manipulation and essential function(s) criteria that define the legal scope of cell-based medicinal products. This article aims to define the authors' viewpoint on the reflection paper. ATMP classification has intrinsic weaknesses derived from the lack of clarity of the evolving concepts of substantial manipulation and essential function(s) as stated in the EU Regulation, leading to the risk of differing interpretations and misclassification. This might result in the broadening of ATMP scope at the expense of other products such as cell/tissue transplants and blood products, or even putting some present and future clinical practice at risk of being classified as ATMP. Because of the major organizational, economic and regulatory implications of product classification, we advocate for increased interaction between CAT and competent authorities (CAs) for medicines, blood and blood components and tissues and cells or for the creation of working groups including representatives of all parties as recently suggested by several CAs.

Dectin-1 and DC-SIGN polymorphisms associated with invasive pulmonary Aspergillosis infection.

The recognition of pathogen-derived structures by C-type lectins and the chemotactic activity mediated by the CCL2/CCR2 axis are critical steps in determining the host immune response to fungi. The present study was designed to investigate whether the presence of single nucleotide polymorphisms (SNPs) within DC-SIGN, Dectin-1, Dectin-2, CCL2 and CCR2 genes influence the risk of developing Invasive Pulmonary Aspergillosis (IPA). Twenty-seven SNPs were selected using a hybrid functional/tagging approach and genotyped in 182 haematological patients, fifty-seven of them diagnosed with proven or probable IPA according to the 2008 EORTC/MSG criteria. Association analysis revealed that carriers of the Dectin-1(rs3901533 T/T) and Dectin-1(rs7309123 G/G) genotypes and DC-SIGN(rs4804800 G), DC-SIGN(rs11465384 T), DC-SIGN(7248637 A) and DC-SIGN(7252229 C) alleles had a significantly increased risk of IPA infection (OR = 5.59 95%CI 1.37-22.77; OR = 4.91 95%CI 1.52-15.89; OR = 2.75 95%CI 1.27-5.95; OR = 2.70 95%CI 1.24-5.90; OR = 2.39 95%CI 1.09-5.22 and OR = 2.05 95%CI 1.00-4.22, respectively). There was also a significantly increased frequency of galactomannan positivity among patients carrying the Dectin-1(rs3901533_T) allele and Dectin-1(rs7309123_G/G) genotype. In addition, healthy individuals with this latter genotype showed a significantly decreased level of Dectin-1 mRNA expression compared to C-allele carriers, suggesting a role of the Dectin-1(rs7309123) polymorphism in determining the levels of Dectin-1 and, consequently, the level of susceptibility to IPA infection. SNP-SNP interaction (epistasis) analysis revealed significant interactions models including SNPs in Dectin-1, Dectin-2, CCL2 and CCR2 genes, with synergistic genetic effects. Although these results need to be further validated in larger cohorts, they suggest that Dectin-1, DC-SIGN, Dectin-2, CCL2 and CCR2 genetic variants influence the risk of IPA infection and might be useful in developing a risk-adapted prophylaxis.

Caracterización de los antígenos específicos del neutrófilo NA1, NA2 y SH en la población argentina / Characterization of neutrophil-specific antigens NA1, NA2 and SH in the argentinean population

Los antígenos especifícos de neutrófilos NA1 (HNA-1a), NA2 (HNA-1b) y SH (HNA-1c) son formas alotípicas del Fc gamma RIIIb y los blancos más frecuentes de los aloanticuerpos antigranulocitarios. El objetivo de este estudio fue determinar las frecuencias alélicas de los antígenos específicos de neutrófilos pertenecientes al sistema HNA-1 en donantes de sangre y amerindios de la etnia Toba de la ciudad de Rosario, Argentina. Se genotipificaron doscientos dieciocho individuos no relacionados para HNA-1a, HNA-1b y HNA-1c mediante reacción en cadena de polimerasa con cebadores secuencia específica (PCR-SSP). Las frecuencias alélicas en los donantes de sangre para HNA-1a y HNA-1b fueron 0,44 y 0,56 respectivamente y en la población amerindia Toba fueron 0,77 y 0,23 respectivamente. El alelo HNA-1c presentó una frecuencia de 0,023 en los donantes de sangre, pero no se detectó en ninguno de los individuos amerindios estudiados. Los presentes datos mostraron que las frecuencias de los alelos que codifican al sistema HNA-1 en la población mayoritaria de Rosario y en la minoritaria amerindia Toba son similares a las descriptas en europeos y otras poblaciones amerindias distantes, respectivamente.

The neutrophil-specific antigens NA1 (HNA-1a), NA2 (HNA-1b) and SH (HNA-1c) are allotypic forms of Fc gamma RIIIb and the most frequent targets of neutrophil alloantibodies. The aim of this study was to determine to gene frequencies of the neutrophil-specific antigens bolonging to the HNA-1 system in blood donors and Toba amerindians fron Rosario, Argentina. Two hundred and eighteen unrelated individual from Rosario were typed for HNA-1a, HNA-1b and HNA-1c, using polymerase chain reaction with sequence-specific primers (PCR-SSP). For the argentinean blood donors, the HNA-1a and HNA-1b gene frequencies were 0.44 and 0.56 and for the amerindians Toba were 0.77 and 0.23 respectively. The HNA-1c gene frequency in blood donors was 0.023 but the allele was absent within the amerindian individuals. The present data showed that the HNA-1 allele frequencies in the major population and the Toba amerindian from Rosario are similar to those described in European and others distant amerindians populations, respectively.

Caracterización de los antígenos específicos del neutrófilo NA1, NA2 y SH en la población argentina / Characterization of neutrophil-specific antigens NA1, NA2 and SH in the argentinean population

Los antígenos especifícos de neutrófilos NA1 (HNA-1a), NA2 (HNA-1b) y SH (HNA-1c) son formas alotípicas del Fc gamma RIIIb y los blancos más frecuentes de los aloanticuerpos antigranulocitarios. El objetivo de este estudio fue determinar las frecuencias alélicas de los antígenos específicos de neutrófilos pertenecientes al sistema HNA-1 en donantes de sangre y amerindios de la etnia Toba de la ciudad de Rosario, Argentina. Se genotipificaron doscientos dieciocho individuos no relacionados para HNA-1a, HNA-1b y HNA-1c mediante reacción en cadena de polimerasa con cebadores secuencia específica (PCR-SSP). Las frecuencias alélicas en los donantes de sangre para HNA-1a y HNA-1b fueron 0,44 y 0,56 respectivamente y en la población amerindia Toba fueron 0,77 y 0,23 respectivamente. El alelo HNA-1c presentó una frecuencia de 0,023 en los donantes de sangre, pero no se detectó en ninguno de los individuos amerindios estudiados. Los presentes datos mostraron que las frecuencias de los alelos que codifican al sistema HNA-1 en la población mayoritaria de Rosario y en la minoritaria amerindia Toba son similares a las descriptas en europeos y otras poblaciones amerindias distantes, respectivamente. (AU)

The neutrophil-specific antigens NA1 (HNA-1a), NA2 (HNA-1b) and SH (HNA-1c) are allotypic forms of Fc gamma RIIIb and the most frequent targets of neutrophil alloantibodies. The aim of this study was to determine to gene frequencies of the neutrophil-specific antigens bolonging to the HNA-1 system in blood donors and Toba amerindians fron Rosario, Argentina. Two hundred and eighteen unrelated individual from Rosario were typed for HNA-1a, HNA-1b and HNA-1c, using polymerase chain reaction with sequence-specific primers (PCR-SSP). For the argentinean blood donors, the HNA-1a and HNA-1b gene frequencies were 0.44 and 0.56 and for the amerindians Toba were 0.77 and 0.23 respectively. The HNA-1c gene frequency in blood donors was 0.023 but the allele was absent within the amerindian individuals. The present data showed that the HNA-1 allele frequencies in the major population and the Toba amerindian from Rosario are similar to those described in European and others distant amerindians populations, respectively. (AU)

Current clinical management of anti-Kell alloimmunization in pregnancy.

OBJECTIVES: Few reports have been published of the current clinical management of anti-Kell alloimmunization in pregnancy; its low frequency of occurrence means that the few long series published have covered very ample time periods in which different kinds of clinical management have overlapped. The objective of the present paper is to present our experience in the current clinical management of pregnant women who are positive for the anti-Kell antibody. STUDY DESIGN: A retrospective analysis was carried out of the case histories of pregnant women who were alloimmunized for the Kell antigen and who were studied and/or treated at the Department of Fetal Medicine in the Virgen de las Nieves University Hospital in Granada (Spain), between 2000 and 2004. The clinical management included the basal measurement of the titre of antibodies, the identification of the paternal phenotype (and that of the fetus, if necessary), the ultrasonographic monitoring of the fetus to detect signs of anaemia, sampling of fetal blood by cordocentesis when fetal anaemia was suspected, and fetal intravascular transfusion when necessary. RESULTS: Of the 10 pregnancies with anti-Kell antibodies, The Kell antigen was confirmed in the fetus in three cases, in all of which moderate to severe fetal anaemia developed, requiring fetal intravascular transfusions. Although one of the fetus developed antenatal hydrops, a good perinatal result was advised. CONCLUSIONS: The current approach to anti-Kell alloimmunization enables pregnant women who have Kell-positive fetuses to be treated successfully.

Interleukin-10 promoter polymorphism as risk factor to develop invasive pulmonary aspergillosis.

This present study was undertaken to examine the role of the host response to Aspergillus fumigatus in the development of clinical symptoms of invasive pulmonary aspergillosis (IPA). The natural outcome and response to IPA infection varies between individuals. Whereas some variation may be attributable to fungi and environmental variables, it is probable that host genetic background also plays a significant role. Interleukin (IL)-10 has a key function in the regulation of cellular immune responses and is involved in various inflammatory diseases. IL-10 promoter carries a polymorphism that has been associated to production levels. Our aim was to investigate the role of this polymorphism in susceptibility to develop IPA infection. The study included 120 haematological patients and 124 age and sex-matched controls and bi-allelic IL-10 -1082(G/A) polymorphism was examined. Genotypic (p=0.385) and allelic frequencies (p=0.527, OR=0.89, 95% CI=0.78-1.60) were similar between patients and healthy controls. IPA was diagnosed in 59 of the 120 patients according to consensus criteria published by the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group (EORTC/IFICG). Our results provide evidence that IL-10 -1082(AA) genotype is associated with resistance to develop IPA (p=0.001). Allele frequency of IL-10 -1082A allele was weakly associated with susceptibility to develop IPA infection (p=0.052). In conclusion, these results suggest that differential production of IL-10 may alter the risk for IPA in haematological patients.

Estimated risk of transfusion-transmitted viral infections in Spain.

BACKGROUND: Estimates of the risk of transfusion-transmitted viral infections are essential for monitoring the safety of the blood supply. The aim of the present study was to estimate the residual risk of blood-borne viral infections in Spain. STUDY DESIGN AND METHODS: Incidence rates of seroconversion for HIV, HBV, and HCV were calculated among 673,018 persons who donated blood more than once (repeat donors), from 1997 through 1999 at 22 blood donation centers (for a total of 2,464,964 allogeneic blood donations and 1,052,752 person-years). RESULTS: Incidence rates per 100,000 person-years and their 95-percent CIs were as follows: for HBV, 8.36 (5.24-12.62); for HIV, 3.23 (2.24-4.52); and for HCV, 3.70 (2.63-5.07). After adjusting incidence rates for the estimated duration of the infectious window period for each virus, the residual risk per unit transfused was estimated at 1 in 513,000 for HIV, 1 in 74,000 for HBV, and 1 in 149,000 for HCV. The introduction of new screening test based on NAT would have reduced these risks by 27 to 50 percent for HIV, by 42 percent for HBV, and by 62 to 65 percent for HCV. CONCLUSION: The residual risks of transmission of HIV, HBV, and HCV in Spain are similar to those reported in other countries and should be further reduced in the future.