Update on iodine-refractory differentiated thyroid carcinoma.

Radioiodine therapy represents a fundamental pillar in the routine adjuvant therapy of patients with high-risk differentiated thyroid carcinoma. However, a non-negligible percentage of these patients will develop iodine refractoriness, showing a worse prognosis, as well a lower survival, which demonstrates a clear need to explore different therapeutic approaches. Iodine refractory patient treatment continues to be a challenge, currently having different novel therapeutic options that should be known by the different specialties related to differentiated thyroid carcinoma (DTC). The aim of this work is to review iodine refractory thyroid carcinoma treatment, focusing especially on the definition of iodine refractoriness, highlighting its importance due to its high mortality, and introducing the different therapeutic options available for these patients.

RADIORYTHMIC: Phase III, Opened, Randomized Study of Postoperative Radiotherapy Versus Surveillance in Stage IIb/III of Masaoka Koga Thymoma after Complete Surgical Resection.

INTRODUCTION: Thymomas are rare intrathoracic malignancies that may be aggressive and difficult to treat. Knowledge and level of evidence for treatment strategies are mainly based on retrospective studies or expert opinion. Currently there is no strong evidence that postoperative radiotherapy after complete resection of localized thymoma is associated with survival benefit in patients. RADIORYTHMIC is a phase III, randomized trial aiming at comparing postoperative radiotherapy versus surveillance after complete resection of Masaoka-Koga stage IIb/III thymoma. Systematic central pathologic review will be performed before patient enrollment as per the RYTHMIC network pathway. PATIENTS AND METHODS: Three hundred fourteen patients will be included; randomization 1:1 will attribute either postoperative radiotherapy (50-54 Gy to the mediastinum using intensity-modulated radiation therapy or proton beam therapy) or surveillance. Stratification criteria include histologic grading (thymoma type A, AB, B1 vs B2, B3), stage, and delivery of preoperative chemotherapy. Patient recruitment will be mainly made through the French RYTHMIC network of 15 expert centers participating in a nationwide multidisciplinary tumor board. Follow-up will last 7 years. The primary endpoint is recurrence-free survival. Secondary objectives include overall survival, assessment of acute and late toxicities, and analysis of prognostic and predictive biomarkers. RESULTS: The first patient will be enrolled in January 2021, with results expected in 2028.

Trimethylamine N-oxide levels are associated with NASH in obese subjects with type 2 diabetes.

AIMS: Trimethylamine N-oxide (TMAO), choline and betaine serum levels have been associated with metabolic diseases including type 2 diabetes (T2D) and non-alcoholic fatty liver disease (NAFLD). These associations could be mediated by insulin resistance. However, the relationships among these metabolites, insulin resistance and NAFLD have not been thoroughly investigated. Moreover, it has recently been suggested that TMAO could play a role in NAFLD by altering bile acid metabolism. We examined the association between circulating TMAO, choline and betaine levels and NAFLD in obese subjects. METHODS: Serum TMAO, choline, betaine and bile acid levels were measured in 357 Mexican obese patients with different grades of NAFLD as determined by liver histology. Associations of NAFLD with TMAO, choline and betaine levels were tested. Moreover, association of TMAO levels with non-alcoholic steatohepatitis (NASH) was tested separately in patients with and without T2D. RESULTS: TMAO and choline levels were significantly associated with NAFLD histologic features and NASH risk. While increased serum TMAO levels were significantly associated with NASH in patients with T2D, in non-T2D subjects this association lost significance after adjusting for sex, BMI and HOMA2-IR. Moreover, circulating secondary bile acids were associated both with increased TMAO levels and NASH. CONCLUSIONS: In obese patients, circulating TMAO levels were associated with NASH mainly in the presence of T2D. Functional studies are required to evaluate the role of insulin resistance and T2D in this association, both highly prevalent in NASH patients.

Development of a leakage monitoring system in isolated limb perfusion with portable gamma camera. / Desarrollo de un protocolo de monitorización de fuga en perfusión de miembro aislado con gammacámara portátil.

Isolated limb perfusion (ILP) is a method for treating unresectable lesions of limbs in patients with melanoma or sarcoma by using high doses of tumor necrosis factor alpha and melphalan. These high doses can result in high systemic toxicity if there is a drug leak from the isolated circulation of the limb to the systemic. This makes it imperative to monitor the leakage rate (F[%]) during the infusion, currently performed with radiotracers. The objective of this work was to develop a leakage monitoring protocol as accurate as possible to ensure safe ILP. MATERIAL AND METHOD: We built a phantom with 3compartments (body, limb and precordial area) and a high sensitivity collimator fitted to a portable gammacamera. We simulate ILP with scheduled leaks every 10minutes from 1% to 9% (theorical F[%]). We mesured F(%) using 2equation: one is the proposed in the literature and another corrected by decay of the radioisotope. We test the optimal radiopharmaceutical doses to minimize the detector dead time error and compare F(%) mesured by both equations regarding the theoretical F(%). The leakage monitoring protocol was used in 17 ILP of 16 patients and an analysis of the recorded data was performed. RESULTS: We found significant differences between F(%) mesured using the first equation and theoretical F(%), obtaining results very adjusted to the theorical after applying the decay correction. CONCLUSIONS: The decay correction of the radioisotope is a simple manner to carry out the procedure more safely, reducing the error in the calculation of F(%).

Protein expression of angiotensin-converting enzyme 2, a SARS-CoV-2-specific receptor, in fetal and placental tissues throughout gestation: new insight for perinatal counseling.

OBJECTIVE: Pregnant women can be infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), yet the incidence of perinatal infection is low. We hypothesized that this could be related to low expression of the membrane receptor for SARS-CoV-2, angiotensin-converting enzyme 2 (ACE2), in the fetoplacental unit. We evaluated protein expression of ACE2 at various gestational ages in both placentae and fetal organs from pregnancies not infected with SARS-CoV-2. METHODS: In May 2020, using samples from a registered biobank, we performed immunohistochemical analysis for ACE2 in tissue samples from fetal organs and placentae from five cases of second- or third-trimester medical termination of pregnancy in healthy women (performed between 15 and 38 weeks' gestation), as well as a further two placentae, one from a 7-week spontaneous miscarriage in a non-infected woman and one from a symptomatic pregnant woman positive for SARS-CoV-2 delivered by Cesarean section at 34 weeks. Samples were paraffin-embedded and organ tissues included kidney, brain, lung, intestinal tract, heart and testis. Matching tissues (kidney, intestinal tract, lung and testis) from autopsies of four 8-year-old children were tested as controls. Tissue sections were incubated with rabbit monoclonal anti-ACE2, and protein expression of ACE2 was detected by immunohistochemistry. RESULTS: ACE2 expression was detected in fetal kidney, rectum and ileum samples from 15 weeks onwards and in the pediatric controls. It was barely detectable in fetal lung samples at 15 + 5 weeks' gestation and not detectable thereafter, and, in the pediatric controls, ACE2 was detectable only in type-2 pneumocytes. No ACE2 expression was found in the cerebral ependymal or parenchymal tissues or in cardiac tissues. ACE2 was expressed in placental syncytiotrophoblast and cytotrophoblast samples, but not in the amnion, from 7 weeks onwards. The intensity and distribution of ACE2 staining in the placenta from the symptomatic SARS-CoV-2 woman was similar to that in the non-infected placentae. CONCLUSIONS: Marked placental expression of ACE2 provides a rationale for vertical transmission at the cellular level. Absence of ACE2 expression in the fetal brain and heart is reassuring regarding the risk of congenital malformation. Clinical follow-up of infected pregnant women and their children is needed to validate these observations. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Selective biopsy of the sentinel node in cancer of cervix: Experience in validation phase. / Biopsia selectiva del ganglio centinela en cáncer de cérvix: experiencia en fase de validación.

BACKGROUND AND OBJECTIVE: Sentinel lymph node biopsy (SLNB) was created to reduce the morbidity associated with pelvic lymphadenectomy in the early stages of cervical cancer (CC), preserving its prognostic information. The goal is to assess the diagnostic validity of SLNB in CC in initial stages (IA1 with lymphovascular infiltration (LVI) +, IA2, IB1 and IIA1), thus avoiding unnecessary lymphadenectomies in many of the cases. MATERIAL AND METHOD: From January 2012 to April 2017, 23 patients with initial stages of CC were included in a cross-sectional study to evaluate the effectiveness of the SLNB in CC with a mixed technique of cervical injection of 99mTc-nanocolloid of albumin and methylene blue, using combined planar lymphoscintigraphy with multimodality SPECT/CT image and subsequent removal of the sentinel node (SN) by laparoscopy. RESULTS: The detection rate of SLNB with the mixed technique was 95.65%, with a negative predictive value (NPV) of 95.45% and sensitivity (S) of 100% in the case of bilateral drainage. The mean of excised SN was 3 (range 1-5). The bilateral detection rate in laparoscopy was 85.35%. The concordance between SPECT/CT and laparoscopy for the number and bilaterality of the SN using the Pearson coefficient was r = 0.727 and r = 0.833, respectively; p = 0.01. We only found one SN with a deferred result of micrometástasis and one false negative was detected. CONCLUSIONS: SLNB in CC using a mixed technique has a high detection and bilateral drainage rate, but S is still low if we include cases of unilateral drainage. A greater number of cases and the development of intraoperative ultrastaging could increase the S of the technique and to reduce the number of false negatives.

Composition of gut microbiota in obese and normal-weight Mexican school-age children and its association with metabolic traits.

BACKGROUND: Childhood obesity is a serious public health problem in Mexico. Adult gut microbiota composition has been linked to obesity, but few studies have addressed the role of gut microbiota in childhood obesity. OBJECTIVES: The aim of this study is to compare gut microbiota composition in obese and normal-weight children and to associate gut microbiota profiles with amino acid serum levels and obesity-related metabolic traits. METHODS: Microbial taxa relative abundance was determined by 16S rRNA sequencing in 67 normal-weight and 71 obese children aged 6-12 years. Serum amino acid levels were measured by mass spectrometry. Associations between microbiota composition, metabolic parameters and amino acid serum levels were tested. RESULTS: No significant differences in phyla abundances or Firmicutes/Bacteroidetes ratios were observed between normal-weight and obese children. However, Bacteroides eggerthii abundance was significantly higher in obese children and correlated positively with body fat percentage and negatively with insoluble fibre intake. Additionally, Bacteroides plebeius and unclassified Christensenellaceae abundances were significantly higher in normal-weight children. Abundance of both these species correlated negatively with phenylalanine serum levels, a metabolite also found to be associated with obesity in Mexican children. CONCLUSIONS: The study identified bacterial species associated with obesity, metabolic complications and amino acid serum levels in Mexican children.

Conflictividad ética en enfermeras/os de unidades de cuidados críticos en un hospital del sur de Chile / Ethical conflicts among nurses in critical care units in a southern Chile hospital / Conflitualidade ética em enfermeiras/os de unidades de cuidados críticos em um hospital do sul do Chile

Introducción: La conflictividad ética ocurre cuando las enfermeras/os no pueden actuar según sus creencias y valores debido a que algo o alguien se lo impiden. Objetivo: Determinar el nivel de conflictividad ética en enfermeras/os de unidades críticas de un hospital del sur de Chile. Métodos: Estudio transversal y de asociación en 38 enfermeras/os de unidades de críticas. Se aplicó el Cuestionario de Conflictividad Ética (CuCEE), con un alfa de Cronbach de 0.82; se adicionó un ítem sociolaboral-académico. Para el análisis se utilizó estadística descriptiva y la prueba Chi-cuadrado de Pearson (nivel de confianza del 95%). Se cumplieron los criterios de rigor ético. Resultados: El 68.4% eran mujeres, con una edad promedio de 33.6 años (DE ± 8.2), del servicio clínico unidad de paciente crítico (UPC) adulto en un 60.5%, con un promedio de antigüedad profesional de 8.7 años y un promedio de trabajo en unidades críticas de 6.9 años (DE ± 4.6). Se observaron niveles altos en frecuencia e intensidad del fenómeno. «Indignación moral¼ fue el tipo de conflictividad ética predominante, con un índice de exposición (IEce) moderado. Las situaciones de mayor conflictividad fueron: «Comprobar que el tratamiento analgésico y/o sedante que se administra al paciente no es suficientemente efectivo y este está sufriendo¼ y «Trabajar con personal médico al que considero profesionalmente incompetente¼. No existió asociación significativa entre variables sociolaborales-académicas e IEce. Conclusiones: Las situaciones de mayor conflicto se relacionan con el sufrimiento de los pacientes y las dinámicas de trabajo. Existen barreras que impiden la acción de cuidar según los valores al observar que otros no proceden éticamente, lo que debe ser considerado dentro de las unidades estudiadas para generar conductas preventivas.

Abstract Introduction: Ethical conflicts arise when nurses cannot perform based on their values and beliefs because someone or something prevents them from doing so. Objective: To determine the level of ethical conflict among nurses in critical care units in a southern Chile hospital. Methods: This is a transversal and association study with 38 nurses of critical care units. The Questionnaire on Ethical Conflict (CuCEE) which has a Cronbach alfa of 0.82 was used. An item on social and work-related issues was added. Descriptive statistics including Pearson Chi square (95% CI) were calculated according to criteria of ethical rigor. Results: 68.4% were women. The average age was 33.6 years old (SD ± 8.2). 60.5% work in adult Critical Patient Unit. The working experience average was 8.7 years. The working experience average within units of critical care was 6.9 years (SD ± 4.6). High levels in frequency and severity of ethical conflicts were observed. Moral indignation was the main type of ethical conflict, though with a moderate exposition index (IEce). The most conflictive situations were: 'Acknow- ledging that the analgesic and sedative treatment given to the patients was not effective enough resulting in their suffering' and 'Working with medical staff who was considered professionally incompetent'. No significant associations were found among the social and work-related and academic variables and IEce. Conclusions: The situations with greater conflict are related to the suffering of the patients and the working dynamics. There are barriers which prevent the provision of a care based on the values. Moreover, observing those who do not proceed ethically further supports the necessity to promote preventive conducts of these behaviors.

Resumo Introdução: A conflitualidade ética ocorre quando as enfermeiras/os não podem agir segundo suas crenças e valores devido a que algo o alguém o impede. Objetivo: Determinar o nível de Conflitualidade Ética, em enfermeiras/os de Unidades Críticas de um hospital do sul do Chile. Métodos: Estudo transversal e de associação em 38 enfermeiras/os de Unidades Críticas. Aplicou-se Questionário de Conflitualidade Ética (CuCEE), com alfa de Cronbach 0.82, adicionou-se um item sociolaboral-académico. Para a análise utilizou-se estatística descritiva e Chi quadrado de Pearson (nível de confiança de 95%.), cumprimento de critérios de rigor ético. Resultados: Mulheres (68.4%), idade média 33.6 anos (DE ± 8.2), de UPC adulto (60.5%), com média de antiguidade profissional de 8.7 anos e uma média de trabalho em Unidades Críticas (DE ± 4,6) de 6.9 anos. Observaram-se níveis altos em frequência e intensidade do fenómeno. Indignação Moral foi o tipo de Conflitualidade Ética predominante, com um Índice de exposição (IEce) moderado. As situações de maior conflitualidade foram «Comprovar que o tratamento analgésico e/o sedante que se administra ao paciente não é suficientemente efetivo e este está sofrendo¼ e «Trabalhar com pessoal médico ao qual considero profissionalmente incompetente¼. Não existiu associação significativa entre variáveis sócio-laborais - académicas e IEce. Conclusões: As situações de maior conflito relacionam-se com o sofrimento dos pacientes e as dinâmicas de trabalho, existem barreiras que impedem a ação de cuidar segundo os valores, ao observar que outros não procedem eticamente, o que deve ser considerado dentro das unidades estudadas para gerar condutas preventivas.

Herramienta de evaluación de tecnologías para la adquisición de equipos biomédicos / Health technology assessment tools for biomedical equipment acquisition / Ferramenta de avaliação de tecnologias para a aquisição de equipamentos biomédicos

La Evaluación de Tecnologías en Salud es una práctica que permite a las Instituciones de Salud valorar de forma integral las consecuencias del uso de una tecnología, sin embargo, la falta de estandarización y de metodologías que guíen el proceso sigue siendo un reto por superar. Este trabajo presenta el desarrollo y la validación de una herramienta de Evaluación de Tecnologías en Salud la cual se realizó en tres fases: primero se desarrolló la herramienta que permite valorar el proceso de adquisición de equipos biomédicos, después se conformó un grupo de discusión para obtener diferentes percepciones frente a la metodología empleada, el diseño y desarrollo de la herramienta para finalmente implementarla mediante casos de estudio evaluando su uso real y aplicando una encuesta que permitió valorar su utilidad en los procesos de adquisición de equipos biomédicos. Se ponderó la importancia de cada tipo de evaluación de tecnologías seleccionada y se desarrollaron los módulos para las evaluaciones técnica, clínica, económica y ética, social y organizacional. Por su parte, la validación con expertos demostró la utilidad de la herramienta en los procesos de selección y adquisición de equipos biomédicos de manera que se disminuyan costos y se realicen mejores inversiones.

Health Technologies Assessment is a practice that enablesthe evaluation of the consequences of the use of a technology. However, the lack of standardization and methodologies that guide the process remains a challenge. This paper presents the development and validation of a Health Technology Assessment tool which process was carried out in three phases. First, the tool was developed to assess the acquisition process of medical equipment, after which a discussion group was formed to obtain different perceptions regarding the tool. Finally,was the implementation through case studies, evaluating its real use and applying an evaluation survey to measure its usefulness in the processes of acquisition of medical equipment. The importance of each type of technology assessment was weighed and modules for technical, clinical, economic, ethical, social and organizational evaluation were developed. In addition, validation with experts demonstrated the usefulness of the tool in the selection and acquisition processes of medical equipment in a way that will reduce costs and enable better investments.

A Avaliação de Tecnologias em Saúde é uma prática que permite às Instituições de Saúde valorizar de forma integral as consequências do uso de uma tecnologia, no entanto, a falta de estandardização e de metodologias que guiem o processo segue sendo um desafio por superar. Este trabalho apresenta o desenvolvimento e a validação de uma ferramenta de Avaliação de Tecnologias em Saúde a qual se realizou em três fases: primeiro desenvolveu-se a ferramenta que permite valorizar o processo de aquisição de equipamentos biomédicos, depois se conformou um grupo de discussão para obter diferentes percepções em frente à metodologia empregada, o desenho e desenvolvimento da ferramenta para finalmente implementá-la mediante casos de estudo avaliando seu uso real e aplicando uma pesquisa que permitiu valorizar sua utilidade nos processos de aquisição de equipamentos biomédicos. Ponderou-se a importância de cada tipo de avaliação de tecnologias selecionadas e desenvolveram-se os módulos para as avaliações técnica, clínica, económica, ética, social e organizacional. Por sua vez, a validação com experientes demonstrou a utilidade da ferramenta nos processos de seleção e aquisição de equipamentos biomédicos de maneira que se diminuam custos e se realizem melhores investimentos.

BCL2 expression but not MYC and BCL2 coexpression predicts survival in elderly patients with diffuse large B-cell lymphoma independently of cell of origin in the phase 3 LNH03-6B trial.

BACKGROUND: Our aim was to evaluate whether the cell of origin (COO) as defined by the Hans algorithm and MYC/BCL2 coexpression, which are the two main biological risk factors in elderly patients treated with rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine, and prednisolone (R-CHOP), maintain their prognostic value in a large prospective clinical trial. PATIENTS AND METHODS: We evaluated 285 paraffin-embedded samples from patients (60-80 years of age) enrolled in the Lymphoma Study Association trial LNH03-6B who were treated with R-CHOP. We correlated the COO defined by the transcriptome according to the Wright algorithm with that defined by the Hans algorithm in a subset of 62 tumors with available frozen tissue samples. RESULTS: The non-germinal center B-cell-like phenotype according to the Hans algorithm and BCL2 expression (but not MYC and BCL2 coexpression) predicted worse progression-free survival [hazard ratio (HR)=1.78, P = 0.003 and HR = 1.79, P = 0.003, respectively] and overall survival (HR = 1.85, P = 0.005 and HR = 1.67, P = 0.02, respectively) independently of the International Prognostic Index. The correlation between the Hans algorithm and the Wright algorithm was 91%, with an almost perfect concordance according to a kappa test (0.81). CONCLUSIONS: Our results suggest that immunohistochemically defined COO remains a useful tool for predicting prognosis in diffuse large B-cell lymphoma when performed under optimized standardized conditions and that BCL2 expression may help to identify elderly patients at risk for relapse and who could potentially respond to anti-BCL2 targeted agents. In this prospective phase III trial, the coexpression of MYC and BCL2 does not appear to predict worse survival. CLINICAL TRIAL NUMBER: NCT00144755.

Penetration and decontamination of americium-241 ex vivo using fresh and frozen pig skin.

Skin contamination is one of the most probable risks following major nuclear or radiological incidents. However, accidents involving skin contamination with radionuclides may occur in the nuclear industry, in research laboratories and in nuclear medicine departments. This work aims to measure the penetration of the radiological contaminant Americium (241Am) in fresh and frozen skin and to evaluate the distribution of the contamination in the skin. Decontamination tests were performed using water, Fuller's earth and diethylene triamine pentaacetic acid (DTPA), which is the recommended treatment in case of skin contamination with actinides such as plutonium or americium. To assess these parameters, we used the Franz cell diffusion system with full-thickness skin obtained from pigs' ears, representative of human skin. Solutions of 241Am were deposited on the skin samples. The radioactivity content in each compartment and skin layers was measured after 24 h by liquid scintillation counting and alpha spectrophotometry. The Am cutaneous penetration to the receiver compartment is almost negligible in fresh and frozen skin. Multiple washings with water and DTPA recovered about 90% of the initial activity. The rest remains fixed mainly in the stratum corneum. Traces of activity were detected within the epidermis and dermis which is fixed and not accessible to the decontamination.

Bone scintigraphy as cornerstone in the diagnosis of Erdheim-Chester disease.

The Erdheim-Chester disease (ECD) is an extremely rare form of non-Langerhans cell histiocytosis. The main difficulty for its diagnosis lies in the wide variety of non-specific symptoms and signs that can occur in the disease process, leading, therefore, to there being no clear-cut algorithm as a guide for an optimal biopsy to confirm the diagnosis. An 81-year-old male with history of diabetes insipidus was admitted due to non-specific respiratory signs. Imaging techniques revealed osteoblastic lesions in the lumbar spine. Whole-body bone-scintigraphy (BS) was performed, in which lesions involving the axial and appendicular skeleton, with different rates of osteoblastic activity, were observed. This highlighted a symmetrical severely intense uptake in the knees, leading to an accurate biopsy specimen that enabled making the definitive diagnosis. BS is a widely available, safe, and inexpensive technique that shows a characteristic pattern of uptake for ECD, thus its use is highly recommended for screening and guiding biopsy if clinical suspicion exists. Furthermore, when the scintigraphy pattern is incidentally observed, biopsy of increased uptake areas (tibia preferably) is mandatory in order to rule out the disease.

Lymphomatoid papulosis in children: a series of 25 cases.

BACKGROUND: Lymphomatoid papulosis (LyP) is an uncommon cutaneous T-cell lymphoproliferative disorder (CTLPD) rarely encountered in children. OBJECTIVES: To specify characteristics of paediatric LyP and to describe both diagnostic difficulties and the course of the disease with the experience of 10 years' follow-up. METHODS: This was a retrospective, single-centre study of 25 children diagnosed with LyP according to the 2008 World Health Organization guidelines, and a clinical and pathological correlation by two experts. RESULTS: The mean age at onset was 7·5 years. The lesions were mostly papulonodular with frequent pruritus (40%). Mucosal involvement was sometimes observed. A single ulcerative nodule was initially suggestive of a primary cutaneous anaplastic large-cell lymphoma (C-ALCL). Pityriasis lichenoides was associated in 36% of cases, atopic dermatitis in 28% and nonspecific infections in 28%. Complete remission was observed in 44% of cases. Through the mean follow-up of 10 years, none of our patients have experienced lymphoma occurrence. Histopathological subtype A clearly predominated (82%). A marked eosinophilic infiltrate was present in 44% of cases and a cutaneous T-gamma clone in 40%. No correlation was observed between histopathological subtype, cutaneous clone or LyP clinical course. CONCLUSIONS: Paediatric LyP belongs to the group of CD30-positive CTLPDs including C-ALCL. Children have to be carefully followed up lifelong, even if the prognosis appears good. The high frequencies of an associated viral infection, atopic dermatitis, marked eosinophilic infiltrate and a good outcome suggest that paediatric LyP could be considered a reactional disease rather than a malignant disorder.

Recommendations for the use of in vitro methods to detect specific immunoglobulin E: are they comparable?

Total and specific immunoglobulin (Ig) E can be detected in vitro using several commercially available methods. The largest share of the global market for these methods is held by the ImmunoCAP technique (Thermo Fisher, previously Phadia), Immulite (Siemens), and Hytec-288 (Hycor). Most comparative studies examine Immulite and ImmunoCAP, which differ methodologically but use similar units of measurement relative to the same standard of total IgE (WHO IgE Standard 75/502). Despite their similarity, these kits differ in their quantification of specific IgE, which varies depending on the allergen studied.Thus, specific IgE results obtained with ImmunoCAP and Immulite are not interchangeable. It is important to bear this in mind, especially when determining cutoff points as predictors of a response to oral challenge with specific food allergens. The method used in practice must be the same as the one in the publication guiding clinical decision making. We analyze differences between ImmunoCAP and ISAC microarray, 2 methods from the same manufacturer used to detect IgE to specific proteins (purified or recombinant).The results show that the IgE values obtained with ImmunoCAP are not equivalent to the corresponding values obtained with the ISAC microarray system.