Exploring the electrical robustness of conductive textile fasteners for wearable devices in different human motion conditions.

Conventional snap fasteners used in clothing are often used as electrical connectors in e-textile and wearable applications for signal transmission due to their wide availability and ease of use. Nonetheless, limited research exists on the validation of these fasteners, regarding the impact of contact-induced high-amplitude artefacts, especially under motion conditions. In this work, three types of fasteners were used as electromechanical connectors, establishing the interface between a regular sock and an acquisition device. The tested fasteners have different shapes and sizes, as well as have different mechanisms of attachment between the plug and receptacle counterparts. Experimental evaluation was performed under static conditions, slow walking, and rope jumping at a high cadence. The tests were also performed with a test mass of 140 g. Magnetic fasteners presented excellent electromechanical robustness under highly dynamic human movement with and without the additional mass. On the other hand, it was demonstrated that the Spring snap buttons (with a spring-based engaging mechanism) presented a sub-optimal performance under high motion and load conditions, followed by the Prong snap fasteners (without spring), which revealed a high susceptibility to artefacts. Overall, this work provides further evidence on the importance and reliability of clothing fasteners as electrical connectors in wearable systems.

A novel portable anechoic chamber using ultra-thin 2D microwave absorber for industrial 5.0.

In this paper, the authors, for the first time, have shown the use of 2D conformal microwave absorbing material (MAM) in the design and fabrication of a portable Anechoic chamber (AC). The MAM is fabricated on the transparent and conductive metal oxide layer named indium-tin-oxide (ITO) with Polyethylene terephthalate as the substrate and the ground plane for zero transmission having overall thickness of 0.012 λ where λ is calculated at 0.7 GHz. The MAM is characterized for 0.7 to 18 GHz for both TE- and TM-polarisation and oblique incidence. High sheet resistance, dipole-like resonance structure patterned on the ITO, and the air-spacing between the layers is optimized to achieve broadband absorption. The MAM is used to line the six sides of the rectangular anechoic chamber having inner dimensions of: (L × W × H: 850 × 650 × 720 mm3). The return loss (RL), gain, and radiation pattern of three antenna working at 1.56, 2.43, and 4.93 GHz are analyzed inside the AC. The measurement results for all frequencies very well match with the simulation studies, thus validating and opening the door for the future use of ultra-thin and planar MAM in the AC.

Equity matrix for kidney transplant allocation.

There is a general agreement that the distribution of kidneys for transplantation should balance utility criteria with justice. Moreover, a kidney allocation system must be based on transparent policies and seen as an ongoing process. This study aims to present an allocation system grounded on an equity matrix that balances the criteria of utility and justice. Synthetic data for a waiting list with 2000 transplant candidates and a pool of 280 donors were generated. A color priority system, the Eurotransplant (ET) kidney allocation system, and the proposed Equity Matrix (EQM) allocation system were compared after 1000 iterations of kidney allocations. Distributions of variables like the age difference, Human Leukocyte Antigens (HLA) mismatches (mmHLA), recipients' time on dialysis, cPRA, and a transplant score obtained by different allocation models were compared graphically and with Cohen's d effect size. For the analyzed variables, when we compare only the selected recipients from ET with the selected recipients from the EQM neutral model, we can conclude that the former model selects more hypersensitized recipients, a higher number of 65+ years' old recipients with 65+ years' old donors and higher number of recipients with 0 mmHLA. While recipients from EQM neutral are slightly older, have a lower age difference with their donors, have a lower number of mmHLA, are less likely to have 6 mmHLA with their donors, and have more time on dialysis. The proposed EQM model attempts to provide a simple, transparent, and equitable response to a complex question with results that outperform established practices.

Feasibility of Electrodermal Activity and Photoplethysmography Data Acquisition at the Foot Using a Sock Form Factor.

Wearable devices have been shown to play an important role in disease prevention and health management, through the multimodal acquisition of peripheral biosignals. However, many of these wearables are exposed, limiting their long-term acceptability by some user groups. To overcome this, a wearable smart sock integrating a PPG sensor and an EDA sensor with textile electrodes was developed. Using the smart sock, EDA and PPG measurements at the foot/ankle were performed in test populations of 19 and 15 subjects, respectively. Both measurements were validated by simultaneously recording the same signals with a standard device at the hand. For the EDA measurements, Pearson correlations of up to 0.95 were obtained for the SCL component, and a mean consensus of 69% for peaks detected in the two locations was obtained. As for the PPG measurements, after fine-tuning the automatic detection of systolic peaks, the index finger and ankle, accuracies of 99.46% and 87.85% were obtained, respectively. Moreover, an HR estimation error of 17.40±14.80 Beats-Per-Minute (BPM) was obtained. Overall, the results support the feasibility of this wearable form factor for unobtrusive EDA and PPG monitoring.

Children then, adults now: long-term outcomes-performance at 15, 20, and 25 years of cochlear implant use.

Motivation: Severe to profound sensorineural hearing loss interferes with a child's development at the cognitive, linguistic, academic, and social levels. Since the beginning of the pediatric auditory rehabilitation program through cochlear implantation in the Ear, Nose, and Throat (ENT) Service of the Coimbra Hospital and University Center (CHUC), Portugal, its mentors defended the early diagnosis of hearing loss followed by timely intervention, and this was considered the starting point to optimize (re)habilitation through this method. Three decades or so later, recently we conducted this study to evaluate the performance of patients implanted in the initial phase of the cochlear implantation program. Objectives: The study aimed to evaluate the performance of individuals with severe to profound congenital hearing loss who underwent pediatric cochlear implantation and have used the cochlear implant for at least 25 years, to analyze the beneficial effect of early intervention in improving performance results. Methods: The study sample is composed of 31 individuals with severe to profound congenital hearing loss and no other comorbidities, divided into two groups (Group 1: age at implantation was under 3 years; Group 2: age at implantation was over 3 years). All 31 subjects were evaluated at 15, 20, and 25 years of cochlear implant (CI) use with a comprehensive set of tests. In addition, data were collected regarding the academic level of each participant. The results of both groups were compared to find out if there is an effect of age at implantation on auditory performance, and if there is an improvement in the performance with CI over time (15, 20, and 25 years of use). Results: The results show that there is a positive effect, with statistical significance, of early implantation on auditory performance, and telephone use. In both groups, there is an increase in performance over time, but it tends to stabilize after 20 years of CI use. Discussion and conclusion: The results obtained in this work support the importance of early intervention in patients with severe to profound hearing loss who are cochlear implant users and show that CI is an effective and reliable method in the treatment of these patients, contributing to their improved socio-educational integration, and that the benefits last over time.

Non-tuberculous mycobacteria: clinical and laboratory characterisation (2009 and 2019).

A cross-sectional and retrospective study of patients with Mycobacterium spp. in a Portuguese tertiary hospital, in 2009 and 2019, was performed to understand better the rise in isolations of nontuberculous mycobacteria (NTM). The number of patients with positive samples for Mycobacterium spp. grew from 56 in 2009 to 83 in 2019. The proportion of NTM rose from 39.3% to 49.4% (P = 0.240), with Mycobacterium avium complex being more frequent in 2009 and Mycobacterium gordonae in 2019, and Mycobacterium tuberculosis complex decreased from 60.7% to 50.6%. Higher age was associated with NTM in both years, and pulmonary disease and immunosuppression were associated with NTM in 2019 (P < 0.05), with weak to moderate correlation (V = 0.231-0.343). The overall rise of NTM, allied to their known capacity to resist antimicrobial therapy, alerts clinicians to the importance of recognising potential risk factors for infection and improving future prevention strategies.

Glycaemic control during the COVID-19 pandemic: A catastrophe or a sign of hope for the person with type 1 Diabetes Mellitus?

INTRODUCTION: In a person with type 1 diabetes, any change concerning daily routine may lead to changes in glycaemic control. This study aimed to evaluate the impact of work and lockdown on glycaemic control in adults with type 1 diabetes. MATERIAL AND METHODS: A retrospective cohort was stratified into three activity groups (g1-students/telework/laid-off; g2-unemployed/retired; g3-work without lockdown). Continuous and categorical variations (reductions≥0.4%) in glycated haemoglobin were obtained in 2020 (t3:December/2019-March/2020; t4:April/2020-July/2020) and in homologous periods of 2019. Intragroup comparisons between years and intergroups in the same year were made. Regression models were developed to predict the variation of glycated haemoglobin in 2020. RESULTS: 241 participants were included, with a significant reduction between t4 and t3 (vs. t2 and t1) in g1 (p<0.001) and g2 (p=0.025) and in 2020 in g1 (vs. g2, p<0.001; vs. g3, p<0.001). Only g1 presented superiority in the reduction ≥0.4% in glycated haemoglobin in 2020 (vs. 2019, p<0.001; vs. g2, p<0.001; vs. g3, p<0.001). The insulin regimens were comparable and the development of hypoglycaemia was found to be superimposed between t3 and t4, except for g1, which was higher at t3 (p=0.029). G1 correlated with continuous reductions (vs. g2, p=0.001; vs. g3, p<0.001) and ≥0.4% in glycated haemoglobin in 2020 (vs. g2, OR 3.6, p<0.001; vs. g3, OR 12.7, p<0.001), regardless of the age and duration of type 1 diabetes. CONCLUSIONS: A more stable and better glycaemic control was observed in participants who transitioned from face-to-face work to total lockdown.

Impact of pharmacological treatment of gestational diabetes on the mode of delivery and birth weight: a nationwide population-based study on a subset of singleton pregnant Portuguese women.

AIMS: To access the impact of increasing use of metformin on cesarean section and large for gestational age rates, when compared to insulin. METHODS: A retrospective observational study was developed using data from the Portuguese National Registry, between 2011 and 2019, of 5038 Portuguese women with single pregnancies and gestational diabetes treated with metformin and/or insulin. Three groups were defined according to the therapeutic regimen adopted: g1-insulin in monotherapy (n = 3027[60.1%]); g2-metformin in monotherapy (n = 1366[27.1%]); g3-metformin and insulin (n = 645[12.8%]). Multivariate analysis was adjusted for statistically significant covariates. RESULTS: The cesarean section rate in g1 was similar to g2 (g1:36.9% vs. g2:37%, p = 0.982), although g3 was associated with cesarean delivery (g3:43.6% vs. g1:36.9%, p = 0.005; g3:43.6% vs. g1:37.0%, p = 0.002), with no differences reported in the multivariate analysis adjusted for year of delivery and pregestational body mass index. A delivery of a large for gestational age newborn was less frequently observed in g2 than in g1 (g2:4.1% vs. g1:5.4%, p = 0.044) and in g3 (g2:4.1% vs. g3:9.1%, p < 0.001), and in g1, when compared to g3 (g1:5.4% vs. g3:9.1%, p < 0.001). In the multivariate analysis, g2 showed lower odds of delivering a large for gestational age newborn, compared to g1 (ß = -0.511, OR = 0.596, CI95% = 0.428-0.832, p < 0.001). CONCLUSIONS: The use of metformin was not associated with higher cesarean section rates, compared to insulin. Instead, it was suggested a protective role of metformin on large gestational age rates. The concomitant use of dual therapy suggests more complex pregnancies, requiring closer surveillance that mitigate serious perinatal and obstetrical outcomes.

Harvesting circuits for triboelectric nanogenerators for wearable applications.

Internet of Things (IoT) and recently Internet of Nano Things (IoNT) bear the promise of new devices able to communicate and assist our daily lives toward wearable technologies which demand a versatile integration such as in wireless body networks (WBN), sensing, and health monitorization. These must comply with stringent constraints on energy usage. Dimensions and complexity intensify the need for small and maintenance-free power sources. Environment energy harvesting and storage is an important approach to sustain operation for a long time. Triboelectric nanogenerators (TENGs) arise as a strong and promising solution to power the new field of outcoming self-sustainable devices, implantable, and wearable devices. They can transform mechanical energy in different modes, have simple structures, and use vulgar and sustainable materials. This paper makes a review about TENGs technology, construction, materials, operation, and focus on strategies for harvesting circuits. Main challenges like efficiency, reliability, energy storage, and sustainability are discussed.

Kidney allocation rules simulator.

The greatest challenge of any kidney transplant program lies in finding enough organ donors (in number and quality) for all waitlisted transplant candidates. Unfortunately, we must resign ourselves to a manifestly insufficient supply of organs for the current demand. Furthermore we must be able to predict kidney transplant success at organ allocation if we want to minimize the number of patients who return to an already overcrowded waiting list for transplantation. Therefore, the definition of deceased donors' kidney allocation rules on transplantation must be supported by simulations that allow foreseeing, as much as possible, the consequences of these rules. Here we present the Kidney Allocation Rules Simulator (KARS) application that enables testing different kidney transplant allocation' systems with different donors and transplant candidates' datasets. In this application, it is possible to simulate allocation rules implemented in Portugal, in the United Kingdom, in countries within Eurtotransplant, and a previously suggested color priority system. As inputs, this application needs three data files: a file with transplant candidates' information, a file with candidates' anti-HLA antibodies, and a file with donors' information. As output, we will have a file with donor-recipient pairs selected according to the kidney allocation system simulated. When seeking waste reduction while ensuring a fair distribution of organs from deceased donors, the definition of rules selecting donor-recipient pairs in renal transplantation must be based on evidence supported by data. On the continuously changing process for a better distribution of an increasingly scarce resource must, we must be able to predict transplant outcomes when defining the best allocation rules.

Glycaemic control during the COVID-19 pandemic: A catastrophe or a sign of hope for the person with type 1 Diabetes Mellitus?

Introduction: In a person with type 1 diabetes, any change concerning daily routine may lead to changes in glycaemic control. This study aimed to evaluate the impact of work and lockdown on glycaemic control in adults with type 1 diabetes. Material and methods: A retrospective cohort was stratified into three activity groups (g1-students/telework/laid-off; g2-unemployed/retired; g3-work without lockdown). Continuous and categorical variations (reductions ≥ 0.4%) in glycated haemoglobin were obtained in 2020 (t3:December/2019-March/2020; t4:April/2020-July/2020) and in homologous periods of 2019. Intragroup comparisons between years and intergroups in the same year were made. Regression models were developed to predict the variation of glycated haemoglobin in 2020. Results: 241 participants were included, with a significant reduction between t4 and t3 (vs. t2 and t1) in g1 (p < 0.001) and g2 (p = 0.025) and in 2020 in g1 (vs. g2, p < 0.001; vs. g3, p < 0.001). Only g1 presented superiority in the reduction ≥0.4% in glycated haemoglobin in 2020 (vs. 2019, p < 0.001; vs. g2, p < 0.001; vs. g3, p < 0.001). The insulin regimens were comparable and the development of hypoglycaemia was found to be superimposed between t3 and t4, except for g1, which was higher at t3 (p = 0.029). G1 correlated with continuous reductions (vs. g2, p = 0.001; vs. g3, p < 0.001) and ≥0.4% in glycated haemoglobin in 2020 (vs. g2, OR 3.6, p < 0.001; vs. g3, OR 12.7, p < 0.001), regardless of the age and duration of type 1 diabetes. Conclusions: A more stable and better glycaemic control was observed in participants who transitioned from face-to-face work to total lockdown.

Introducción: En una persona con diabetes tipo 1, cualquier cambio en la rutina diaria puede provocar cambios en el control glucémico. Este estudio tuvo como objetivo evaluar el impacto del trabajo y el confinamiento en el control glucémico en adultos con diabetes tipo 1. Material y métodos: Se estratificó una cohorte retrospectiva en tres grupos de actividad (g1-estudiantes/teletrabajo/despido; g2-desempleados/jubilados; g3-trabajo sin encierro). Se obtuvieron variaciones continuas y categóricas (reducciones ≥ 0,4%) en la hemoglobina glucosilada en 2020 (t3: diciembre/2019-marzo/2020; t4: abril/2020-julio/2020) y en períodos homólogos de 2019. Se desarrollaron modelos de regresión para predecir la variación de la hemoglobina glucosilada en 2020. Resultados: Se incluyeron 241 participantes, con una reducción significativa entre t4 y t3 (vs. t2 y t1) en g1 (p < 0,001) y g2 (p = 0,025) y en 2020 en g1 (vs. g2, p < 0,001; vs. g3, p < 0,001). Solo g1 demostró superioridad en la reducción ≥ 0,4% de la hemoglobina glucosilada en 2020 (vs. 2019, p < 0,001; vs. g2, p < 0,001; vs. g3, p < 0,001). Los regímenes de terapia con insulina fueron comparables y el desarrollo de hipoglucemia fue superponible entre t3 y t4, excepto para g1, que fue mayor en t3 (p = 0,029). G1 se correlacionó con reducciones continuas (vs. g2, p = 0,001; vs. g3, p < 0,001) y ≥ 0,4% en la hemoglobina glucosilada en 2020 (vs. g2, odds ratio [OR] 3,6, p < 0,001; vs. g3, OR 12,7, p < 0,001), independientemente de la edad y la duración de la diabetes tipo 1. Conclusiones: Se observó un control glucémico más optimizado a los participantes que pasaron del trabajo presencial al confinamiento total.

In search of intangible connections: intellectual capital, performance and quality of life in higher education institutions.

This study explores the contributions of different dimensions of the intellectual capital of higher education institutions (ICHEIs) to their performance, incorporating the previously unexplored dimension of quality of life (QoL) as a performance measure, and correspondingly taking into account the connection between the Theory of Stakeholders and the Theory of Legitimacy. Applying a Structural Equation Model and the Partial Least Squares method, we present new empirical findings from a sample of 738 students and 587 lecturers/researchers from seven Portuguese public HEIs. The ICHEIs positively influence the institution's performance, through relational capital and structural capital; and QoL emerges as an important dimension of HEIs' performance standards, especially regarding students' perception of academic QoL. When HEIs understand and measure their IC, they will gain a better understanding of their core competencies, enabling a better allocation of resources and implementation of more effective strategic and operational actions. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10734-020-00653-9.

Guillain-Barré syndrome as the first presentation of human immunodeficiency virus infection.

AIM: Antiretroviral therapy (ART) development has reduced the severity of neurological complications of the human immunodeficiency virus (HIV), but they remain prevalent and need prompt recognition. Acute inflammatory demyelinating polyneuropathy (AIDP) is a rare complication of human immunodeficiency virus (HIV) infection that may appear at any stage of the disease. In this case, AIDP represents a late presentation of HIV infection. METHODS: Descriptive study. Patient data were collected from their medical records and by health assessment interviews. RESULTS: We report a case of a 52-year-old male with acute lower limb weakness. Given the suggestive clinical presentation of AIDP and a positive HIV test, intravenous immunoglobulin (IVIG) was administered along with antiretroviral therapy. Progressive weakness to the upper limbs, autonomic dysfunction, and pain was observed. The second regimen of IVIG plus corticosteroids was administered. Muscle strength improved after three weeks. CONCLUSIONS: Screening for HIV in a patient with AIDP may provide a better outcome because of the early start of ART with good central nervous system penetration in HIV-infected patients.

Cytokine gene polymorphisms in Pigeon Breeder's Disease expression.

BACKGROUND: Exaggerated immunological response to repeated inhalation of organic or chemical dusts may lead to Hypersensitivity Pneumonitis among sensitized individuals. Only a few exposed individuals became ill and disease expression pattern is highly variable which suggest that genetic factors may play a role. AIM: To investigate interferon (IFN)-γ, tumour necrosis factor (TNF)-α, interleukin (IL)-6, transforming growth factor (TGF)-ß, and IL-10 gene polymorphisms in a cohort of pigeon breeder's disease (PBD) patients in comparison with exposed but healthy controls and the association with different patterns of disease. METHODS: We evaluated 40 PBD patients and 70 exposed controls. IFN-γ, TNF-α, IL-6, TGF-ß, and IL-10 polymorphisms were determined by polymerase chain reaction-sequence specific primer amplification. RESULTS: Polymorphism analysis of IFN-γ, TNF-α, IL-6, TGF-ß, and IL-10 genotypes and allele frequencies showed no differences between patients and controls. IFN-γ T/T genotype frequency was increased among patients with chronic presentation (RR=2.33, p=0.047) compared with those with acute/subacute presentation. Also, chronic presenting patients had an increased frequency of IFN-γ T allele (50% vs 22.5%, RR=1.76, p=0.011). No differences were found in TNF-α, IL-6, TGF-ß, and IL-10 genotypes neither allelic frequencies between both groups of patients. IL-6 C/C genotype was more frequent in patients who showed chronic evolution (RR=2.54, p=0.017), when comparing with patients with disease resolution. CONCLUSION: IFN-γ T/T and the IL-6 C/C genotypes seem to play a role in HP expression due to avian exposure, as their frequencies are increased in chronic presentations or in those with chronic evolution one year after the initial diagnosis, respectively. (Sarcoidosis Vasc Diffuse Lung Dis 2020; 37 (3): e2020004).

Low Operating Voltage Carbon-Graphene Hybrid E-textile for Temperature Sensing.

Graphene-coated polypropylene (PP) textile fibers are presented for their use as temperature sensors. These temperature sensors show a negative thermal coefficient of resistance (TCR) in a range between 30 and 45 °C with good sensitivity and reliability and can operate at voltages as low as 1 V. The analysis of the transient response of the temperature on resistance of different types of graphene produced by chemical vapor deposition (CVD) and shear exfoliation of graphite (SEG) shows that trilayer graphene (TLG) grown on copper by CVD displays better sensitivity due to the better thickness uniformity of the film and that carbon paste provides good contact for the measurements. Along with high sensitivity, TLG on PP shows not only the best response but also better transparency, mechanical stability, and washability compared to SEG. Temperature-dependent Raman analysis reveals that the temperature has no significant effect on the peak frequency of PP and expected effect on graphene in the demonstrated temperature range. The presented results demonstrate that these flexible, lightweight temperature sensors based on TLG with a negative TCR can be easily integrated in fabrics.

Leaf water potential of coffee estimated by landsat-8 images.

Traditionally, water conditions of coffee areas are monitored by measuring the leaf water potential (ΨW) throughout a pressure pump. However, there is a demand for the development of technologies that can estimate large areas or regions. In this context, the objective of this study was to estimate the ΨW by surface reflectance values and vegetation indices obtained from the Landsat-8/OLI sensor in Minas Gerais-Brazil Several algorithms using OLI bands and vegetation indexes were evaluated and from the correlation analysis, a quadratic algorithm that uses the Normalized Difference Vegetation Index (NDVI) performed better, with a correlation coefficient (R2) of 0.82. Leave-One-Out Cross-Validation (LOOCV) was performed to validate the models and the best results were for NDVI quadratic algorithm, presenting a Mean Absolute Percentage Error (MAPE) of 27.09% and an R2 of 0.85. Subsequently, the NDVI quadratic algorithm was applied to Landsat-8 images, aiming to spatialize the ΨW estimated in a representative area of regional coffee planting between September 2014 to July 2015. From the proposed algorithm, it was possible to estimate ΨW from Landsat-8/OLI imagery, contributing to drought monitoring in the coffee area leading to cost reduction to the producers.

In vivo systemic toxicity assessment of an oxidized dextrin-based hydrogel and its effectiveness as a carrier and stabilizer of granular synthetic bone substitutes.

The worldwide incidence of bone disorders is raising, mainly due to aging population. The lack of effective treatments is pushing the development of synthetic bone substitutes (SBSs). Most ceramic-based SBSs commercially available display limited handling properties. Attempting to solve these issues and achieve wider acceptance by the clinicians, granular ceramics have been associated with hydrogels (HGs) to produce injectable/moldable SBSs. Dextrin, a low-molecular-weight carbohydrate, was used to develop a fully resorbable and injectable HG. It was first oxidized with sodium periodate and then cross-linked with adipic acid dihydrazide. The in vivo biocompatibility and safety of the dextrin-based HG was assessed by subacute systemic toxicity and skin sensitization tests, using rodent models. The results showed that the HG did not induce any systemic toxic effect, skin reaction, or genotoxicity, neither impaired the bone repair/regeneration process. Then, the HG was successfully combined with granular bone substitute, registered as Bonelike (250-500 µm) to obtain a moldable/injectable SBS, which was implanted in tibial fractures in goats for 3 and 6 weeks. The obtained results showed that HG allowed the stabilization of the granules into the defect, ensuring effective handling, and molding properties of the formulation, as well as an efficient cohesion of the granules. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1678-1689, 2019.

Portuguese calculated panel reactive antibodies online estimator.

Calculated panel reactive antibodies (CPRA) is a sensitization measure used to classify and prioritize transplant candidates in different kidney transplant allocation systems. CPRA is based on identification of HLA unacceptable on potential organ donors making a transplant candidate ineligible for transplantation. Here, we present a CPRA online estimator based on HLA allelic and haplotypic frequencies from Portuguese donors. We also compare the values we obtained from our CPRA estimator (Portuguese [PT]-CPRA) against CPRA values obtained from: Eurotransplant virtual PRA calculator (ET-CPRA); Canadian CPRA calculator (Canadian [CN]-CPRA) and Organ Procurement and Transplantation Network CPRA calculator (United States [US]-CPRA). When we analyzed correlations between CPRA values obtained from pairs of calculators, we observed that they are significantly and highly correlated. Bland-Altman plots for the comparison between PT-CPRA calculator against the other calculators, show higher differences between PT and CN than between PT and ET and PT and US. Also, the lowest value for Lin's concordance coefficient was obtained for the comparison between PT and CN calculators. CPRA values reliability depend on donors' pool from which it is calculated and it is crucial for classify correctly highly sensitized patients. A CPRA calculator must use donors' HLA frequencies similar from those who would be actual organ donors.

Non-classical human leucocyte antigens in ankylosing spondylitis: possible association with HLA-E and HLA-F.

OBJECTIVES: Ankylosing spondylitis (AS) is the most prevalent form of spondyloarthritis, with a known genetic association with the HLA-B27 molecule. The aim of this study was to assess the contribution of the HLA-G, HLA-E and HLA-F to AS susceptibility/protection in Portuguese patients with HLA-B27 AS and HLA-B27 unaffected controls. METHODS: High-resolution typing of HLA-G, HLA-E and HLA-F was performed in 228 patients with HLA-B27 AS and 244 HLA-B27 unaffected controls. Allelic, genotypic and haplotypic frequencies were compared between cohorts. To replicate the results, single nucleotide polymorphisms (SNPs) in HLA-E and HLA-F genes were typed in Australian cohorts. For further confirmation, a group of European-descent patients with AS and unaffected controls were genotyped for Major Histocompatibility Complex SNPs using the Illumina microarray. RESULTS: In the Portuguese population, no significant differences were found in HLA-G. For HLA-E, a significant difference was detected for the genotype HLA-E*01:01:01/01:03:01 (p=0.009; pc=0.009; OR=0.51), with a protection effect. For HLA-F, significant differences were detected in the allele HLA-F*01:01:02 (p=0.0049; pc=0.0098; OR=0.60) and corresponding SNP rs2075682 (p=0.0004; pc=0.0008; OR=0.53), suggesting protection and in the genotype HLA-F*01:01:01/01:03:01 (p=0.011; pc=0.043; OR=2.00), suggesting a susceptibility effect. Three G-E-F haplotypes with significant differences were detected but occur in a very small number of individuals. The only significant differences detected in the replication studies were for HLA-E rs1059510 in the Australians and for HLA-F rs1736924 in the European-descent cohorts. CONCLUSION: Our results reveal suggestive AS protective and susceptibility effects from both HLA-E and HLA-F loci, however with population differences. To our knowledge, this is the first study showing association of HLA-F with AS.