IgE-Mediated Sensitization to Blo t 21 and Blo t 5 Is Associated With Asthma in the Tropics: A Case-Control Study.

BACKGROUND AND OBJECTIVE: Sensitization to Blomia tropicalis is associated with asthma in various tropical and subtropical countries; however, information about the specific molecular components associated with this disease is scarce. Using molecular diagnosis, we sought to identify B tropicalis allergens associated with asthma in Colombia. METHODS: Specific IgE (sIgE) to 8 B tropicalis recombinant allergens (Blo t 2, 5, 7, 8, 10, 12, 13, and 21) was determined using an in-house ELISA system in asthma patients (n=272) and controls (n=298) recruited in a national prevalence study performed in several Colombian cities (Barranquilla, Bogotá, Medellín, Cali, and San Andrés). The study sample included children and adults (mean [SD] age, 28 [17] years). Cross-reactivity between Blo t 5 and Blo t 21 was evaluated using ELISA-inhibition. RESULTS: Specific IgE (sIgE) to 8 B tropicalis recombinant allergens (Blo t 2, 5, 7, 8, 10, 12, 13, and 21) was determined using an in-house ELISA system in asthma patients (n=272) and controls (n=298) recruited in a national prevalence study performed in several Colombian cities (Barranquilla, Bogotá, Medellín, Cali, and San Andrés). The study sample included children and adults (mean [SD] age, 28 [17] years). Cross-reactivity between Blo t 5 and Blo t 21 was evaluated using ELISA-inhibition. CONCLUSION: Although Blo t 5 and Blo t 21 are considered common sensitizers, this is the first report of their association with asthma. Both components should be included in molecular panels for diagnosis of allergy in the tropics.

Clinical and Sociodemographic Features of Alopecia Areata in Five Colombian Cities: An Analysis of the RENAAC Registry.

BACKGROUND: Alopecia areata (AA) is an autoimmune disease characterized by non-scaring hair loss and preservation of hair follicles. The information available on disease course, and clinical features of AA is scarce worldwide, and almost nonexistent in Colombia. OBJECTIVE: To determine the clinical and sociodemographic characteristics of patients diagnosed with AA who presented to a dermatology consultation in five Colombian cities. MATERIAL AND METHODS: This was a retrospective and multicenter study on data from an ongoing National Registry of Alopecia Areata in Colombia (RENAAC) collected in Bogota, Cali, Cartagena, Barranquilla, and Medellin, Colombia from March 2022 through April 2023. Data was recorded in a standardized form by trained physicians. The variables were expressed as measures of central tendency and dispersion, and absolute and relative frequencies. RESULTS: A total of 562 patients were included, 59.4% of whom were women, aged between 15 and 49 years (63.9%) with a mean disease course of 1.7 years. The most common finding was multiple plaque (53.2%), the predominant AA subtype was patchy (71.4%), and 29.5% of the patients had a past dermatological history, 18.3% had a past endocrinological history, and 8.9% had a past psychiatric history. The treatments most widely used were steroid injections (76.4%), 5% topical minoxidil (46.4%), followed by high-potency corticosteroids (42.5%). STUDY LIMITATIONS AND CONCLUSIONS: AA was slightly predominant in women. As seen in other populations, this disease had an earlier onset in men vs women. Presentation in pediatric age was uncommon. The previous history of other dermatological diseases was checked in almost one third of the patients. Analysis of the co-presentation of AA with other autoimmune diseases is biased due to excluding patients with systemic erythematous lupus from the study.

IgE sensitization to Blo t 21 and Blo t 5 is associated with asthma in the tropics: a case-control study.

BACKGROUND AND OBJECTIVES: Blomia tropicalis sensitization is associated with asthma in different tropical and sub-tropical countries; however, information about the specific molecular components associated with this disease is scarce. Using molecular diagnosis, we sought to identify B. tropicalis allergens associated with asthma in Colombia. METHODS: Specific IgE (sIgE) to eight B. tropicalis recombinant allergens (Blo t 2/5/7/8/10/12/13 and 21) was determined using an in-house developed ELISA system in asthmatic patients (n=272) and control subjects (n=298) recruited in a national prevalencestudy performed in Colombian cities (Barranquilla, Bogotá, Medellín, Cali and San Andrés). Sample study included children and adults (mean age: 28±SD 17 years old). Cross-reactivity between Blot 5 and Blo t 21 was evaluated by ELISA-inhibition. RESULTS: Sensitization to Blo t 21 (aOR: 1.9; 95% CI: 1.2 - 2.9) and Blo t 5 (aOR: 1.6; 95%CI: 1.1 - 2.5), but not Blo t 2, was associated with asthma. sIgE levels to Blo t 21 and to Blo t 5 were significantly higher in the disease group. Cross-reactivity between Blo t 21 and Blo t 5 is on average moderate; however, individual analysis indicates that may be high (>50%) in some cases. CONCLUSIONS: Although Blo t 5 and Blo t 21 has been described as common sensitizers, this is the first report of their association with asthma. Both components should be included in molecular panels for allergy diagnosis in the tropics.

[Willingness to receive the COVID-19 vaccine in the population aged 80 years and older in Colombia 2021]. / Disposición a recibir la vacuna contra COVID-19 en población de 80 y más años en Colombia 2021.

Objective: Colombia designed and adopted a vaccination plan against COVID-19 that will immunize 35 million people. The aim study was to know the willingness to accept the vaccination against COVID-19. Methods: A telephone survey of 11,721 people aged 80 and over, affiliated with a health insurer, was carried. The respondents were the affiliates or their relatives or caregivers. Results: The average age was 85.0 years (SD: 4.5), with no differences between sexes; 3,344 (28.5%) referred a previous diagnostic test for COVID-19 and 73 were positive for an incidence of 622.8 per 100,000 people (95%CI: 491-778). Regarding the attitude with the vaccination against SARS-CoV-2, 1/4 respondents refrained from giving an opinion or was neutral. When the respondent was a relative, the acceptance of the vaccine was 60.4% (95% CI: 59.5-61.3) with differences by gender: men 62.2% (95% CI: 60.8-63.6) and women of 59.2 (95% CI: 58.0-60.3), P < 0.05. When the respondent was the potential recipient of the vaccine, the acceptance of the vaccine was 61.7% (95% CI: 59.4-64.0) and also differed by gender: 70.2% in men (95% CI: 66, 9-73.5) and 55.1% in women (95% CI: 52.0-58.3), P < 0.05. Conclusion: The relatively low acceptance of vaccination against COVID-19 in Colombia poses significant challenges to achieve herd immunity that allows control of the pandemic.

A recombinant cystatin from Ascaris lumbricoides attenuates inflammation of DSS-induced colitis.

Helminthiasis may ameliorate inflammatory diseases, such as inflammatory bowel disease and asthma. Information about immunomodulators from Ascaris lumbricoides is scarce, but could be important considering the co-evolutionary relationships between helminths and humans. We evaluated the immunomodulatory effects of a recombinant cystatin from A. lumbricoides on an acute model of dextran sodium sulphate (DSS)-induced colitis in mice. From an A. lumbricoides cDNA library, we obtained a recombinant cystatin (rAl-CPI). Protease activity inhibition was demonstrated on cathepsin B and papain. Immunomodulatory effects were evaluated at two intraperitoneal doses (0.5 and 0.25 µg/G) on mice with DSS-induced colitis. Body weight, colon length, Disease Activity Index (DAI), histological inflammation score, myeloperoxidase (MPO) activity, gene expression of cytokines and cytokines levels in colon tissue were analysed. Treatment with rAl-CPI significantly reduced DAI, MPO activity and inflammation score without toxic effects. Also, IL-10 and TGF-B gene overexpression was observed in rAl-CPI-treated group compared to DSS-exposed control and healthy mice. Furthermore, a reduction in IL-6 and TNF-A expression was found, and this was confirmed by the levels of these cytokines in colonic tissue. In conclusion, rAl-CPI reduces inflammation in a mouse model of DSS-induced colitis, probably by increasing the expression of anti-inflammatory cytokines and reducing pro-inflammatory ones.

Prediction of the Efficacy of Antihistamines in Chronic Spontaneous Urticaria Based on Initial Suppression of the Histamine- Induced Wheal.

BACKGROUND: Antihistamines are the first line of treatment for chronic spontaneous urticaria. However, there is no effective method to predict whether an antihistamine will have a beneficial clinical effect or not. OBJECTIVE: To assess whether the change in histamine-induced wheal and flare measurements 24 hours after administration of antihistamine can predict the efficacy of treatment. METHODS: We performed a multicenter, triple-blind, randomized study. Patients received a daily oral dose of cetirizine, fexofenadine, bilastine, desloratadine, or ebastine over 8 weeks. After 4 weeks, a higher dose of antihistamine was administered to patients who did not experience a clinical response. A histamine skin prick test was carried out at baseline and 24 hours after the first dose of antihistamine. Disease severity (Urticaria Activity Score [UAS]), response to the histamine skin prick test, and impact on the patient's quality of life (Dermatology Life Quality Index [DLQI]) were determined every 2 weeks. RESULTS: The study population comprised 150 patients (30 per group) and 30 controls. Twenty-four hours after administration of antihistamine, inhibition of the histamine wheal by >75% was significantly associated with better UAS and DLQI scores. The safety and efficacy of the 5 antihistamines were similar. After updosing, rates of disease control (DLQI score <5) increased from 58.7% to 76.7%. CONCLUSIONS: Measurement of the histamine-induced wheal can predict which patients will have a strong clinical response to antihistamines but has limited utility for identifying nonresponders. The clinical significance of these data could be relevant in the search for new urticaria treatment regimens.

Prediction of the efficacy of antihistamines in chronic spontaneous urticaria based on initial suppression of the histamine-induced wheal

Background: Antihistamines are the first line of treatment for chronic spontaneous urticaria. However, there is no effective method to predict whether an antihistamine will have a beneficial clinical effect or not. Objective: To assess whether the change in histamine-induced wheal and flare measurements 24 hours after administration of antihistamine can predict the efficacy of treatment. Methods: We performed a multicenter, triple-blind, randomized study. Patients received a daily oral dose of cetirizine, fexofenadine, bilastine, desloratadine, or ebastine over 8 weeks. After 4 weeks, a higher dose of antihistamine was administered to patients who did not experience a clinical response. A histamine skin prick test was carried out at baseline and 24 hours after the first dose of antihistamine. Disease severity (Urticaria Activity Score [UAS]), response to the histamine skin prick test, and impact on the patient’s quality of life (Dermatology Life Quality Index [DLQI]) were determined every 2 weeks. Results: The study population comprised 150 patients (30 per group) and 30 controls. Twenty-four hours after administration of antihistamine, inhibition of the histamine wheal by >75% was significantly associated with better UAS and DLQI scores. The safety and efficacy of the 5 antihistamines were similar. After updosing, rates of disease control (DLQI score <5) increased from 58.7% to 76.7%. Conclusions: Measurement of the histamine-induced wheal can predict which patients will have a strong clinical response to antihistamines but has limited utility for identifying nonresponders. The clinical significance of these data could be relevant in the search for new urticaria treatment regimens (AU)

Antecedentes: Los antihistamínicos son la primera línea de tratamiento en la urticaria crónica espontanea (UCS) pero actualmente no hay un método eficaz para predecir si un antihistamínico tendrá un efecto clínico beneficioso o no. Objetivo: Evaluar si la prueba cutánea con histamina puede predecir la efectividad del tratamiento con antihistamínicos. Métodos: Se realizó un estudio multicéntrico, triple ciego, aleatorizado. Los pacientes recibieron una dosis oral diaria de cetirizina, fexofenadina, bilastina, desloratadina o ebastina durante 8 semanas. Después de 4 semanas, en los pacientes sin respuesta clínica, se administró una dosis más alta de antihistamínico. Al inicio del estudio, después de 24 horas y cada dos semanas tras la primera administración de los antihistamínicos, se llevó a cabo una prueba intraepidérmica con histamina. La severidad de la enfermedad (escala UAS) y el impacto en la calidad de vida de los pacientes (escala DLQI) fueron evaluados cada dos semanas. Resultados: 150 pacientes (n = 30, en cada grupo) y 30 sujetos control participaron en este estudio. Después de 24 horas de la administración de antihistamínicos, una inhibición de histamina mayor al 75% del basal, se asoció significativamente con mejores resultados en el UAS y el DLQI. La seguridad y eficacia de los cinco antihistamínicos fueron similares. Después de aumentar la dosis, las tasas de control de la enfermedad (puntuación DLQI <5) paso de 58,7% a 76,7%. Conclusiones: La prueba intraepidérmica con histamina es útil para predecir a los pacientes que tendrán una importante respuesta clínica a los antihistamínicos, pero tiene una utilidad limitada para la identificación de los no respondedores. Estos datos pueden ser relevantes en el momento de establecer nuevos esquemas para el tratamiento de la urticaria (AU)

Immunological characterization of a Blo t 12 isoallergen: identification of immunoglobulin E epitopes.

BACKGROUND: Differences in the IgE response to isoallergens could have clinical implications; therefore, its analysis will contribute to the design of better strategies for the diagnosis and treatment of allergic respiratory diseases. Several isoforms have been described from mites but there is no information about the clinical impact of Blomia tropicalis isoallergens. OBJECTIVE: To evaluate the differences in the IgE response against two Blo t 12 isoallergens. METHODS: The IgE-binding properties of Blo t 12 isoallergens were analysed by ELISA, a skin prick test and ELISA cross-inhibition. Epitope mapping was performed using synthetic overlapping peptides. Fold recognition methods were used to model the chitin-binding domain of the two isoallergens. RESULTS: The frequency and strength of the IgE response were greater for Blo t 12.0101 than for Blo t 12.0102. Three IgE-binding areas were identified in Blo t 12.0101; one of them included two residues that are different in Blo t 12.0102. Modelling of the chitin-binding domains of these allergens predicted that they have structural differences that could influence antibody recognition of one of these epitopes. CONCLUSION: In silico structural analysis and immunological characterization of Blo t 12 reveals that allergen polymorphism influences IgE reactivity. Blo t 12.0101 is the most IgE-reactive isoform in Cartagena. The identified IgE epitopes could be mutated to obtain hypoallergenic molecules of potential use for immunotherapy.