Inmunogenicidad y capacidad protectora de variantes de la nueva vacuna antialérgica PROLINEM DS / mmunogeni city and protective efficacy of variants of a novel PROLINEM DS anti - allergic vaccine

Introducción: La vacuna antialérgica de segunda generación PROLINEM-DS está compuesta por alérgenos del ácaro Dermatophagoides siboney y la combinación de adyuvantes: proteoliposoma de N. meningitidis B y gel de hidróxido de aluminio. La adsorción del alérgeno es relevante para la seguridad y eficacia clínica de las vacunas adsorbidas en gel de hidróxido de aluminio en estudios previos se demostró la influencia negativa de los iones fosfato en la adsorción del alérgeno. Objetivo: Evaluar la inmunogenicidad y capacidad protectora de cuatro variantes de formulación obtenidas dentro del espacio de diseño de la vacuna PROLINEM DS. Métodos: Se emplearon 4 variantes de formulación con diferentes contenidos de tampón fosfato salino y gel de hidróxido de aluminio. Se administraron a ratones BALB/c 3 dosis subcutáneas una por semana. Luego, los ratones fueron sometidos a reto alergénico por aerosol. Resultados: Todas las variantes indujeron anticuerpos IgG1 e IgG2a alérgeno específico. Este efecto se correlacionó con el balance de citoquinas proinflamatorias Th1/Th2 en los pulmones y en los ganglios. La variante con reducción de tampón fosfato salino y gel de hidróxido de aluminio fue la de mayor índice IgG/IgE después de la vacunación. Esta relación muestra, en una variable, el equilibrio entre los componentes potencialmente bloqueadores y efectores. La tolerancia local en el lugar de la inyección mostró una reducción de los granulomas en los ratones vacunados con menos gel de hidróxido de aluminio. Conclusiones: La reducción del contenido de gel de hidróxido de aluminio y fosfatos se consideran mejoras farmacéuticas sin inconvenientes en cuanto a la inmunogenicidad de esta vacuna con un perfil de seguridad satisfactorio para futuros ensayos clínicos en humanos.

Introduction: The second generation anti allergic vaccine named PROLINEM DS is based on allergens from D. siboney house dust mite and a combination adjuvant containing PL and Alum. Allergen adsorption is relevant both safety and clinical efficacy in alum-adsorbed vaccines. Negative influence of phosphate ions on allergen adsorption was demonstrated in previous researches. Objective: To evaluate immunogenicity and protective efficacy of four variants obtained within design space of PROLINEM DS vaccine. Methods: Four variants were differentiated from each other by both phosphate and alum contents. Balb/c mice were administered with 3 doses by subcutaneous route. Further, mice were subjected to allergen aerosol challenge. Results: Specific IgG1 and IgG2a antibodies were induced by four vaccine variants. It was correlated with pro inflammatory cytokines balance Th1/Th2 both in lungs and lymphatic nodes. Formulation with lower PBS and Alum levels showed the highest IgG/IgE ratio at the end of vaccination schedule. This ratio shows in one variable the balance between potentially blocking and effector components. Mice injected with lower level of Alum showed a reduction of granuloma size in the site of vaccine administration. Conclusion: Decrease both alum and phosphate contents were a pharmaceutical improvement for antiallergic vaccines formulation. Safety and efficacy in this vaccine are crucial for future human clinical trials.

Inactivación del virus Zika con medio de transporte de ácidos nucleicos, potencialmente aplicable a muestras clínicas para el diagnóstico molecular de SARS-CoV-2 / Inactivation of Zika virus with nucleic acids transport media, potentially applicable to clinical samples for the molecular diagnosis of SARS-CoV-2

RESUMEN Introducción: Los medios de colecta de muestras clínicas con capacidad de desnaturalizar virus reducen los riesgos de contagio durante el transporte y procesamiento. Objetivo: Emplear el medio de transporte de ácidos nucleicos (TAN) en muestras de exudado nasofaríngeo colectadas para el diagnóstico de SARS-CoV-2. Métodos: Se realizó un estudio experimental para demostrar la capacidad del medio de inactivar la infectividad viral. Se tomó como modelo de virus envuelto el virus Zika (VZk), cuyo nivel de bioseguridad es 2. Se evaluó el desempeño clínico del medio TAN para el diagnóstico de SARS-CoV-2. Se empleó una cepa del VZk propagada en la línea celular Vero y, previo a la infección de las células, el VZk se puso en contacto a intervalos de tiempo diferentes (2; 15 y 30 min) con el medio TAN puro; y luego se realizaron diluciones seriadas (10-1-10-4). La inactivación viral se evaluó por RT-PCR, en el sobrenadante y células colectadas, al culminar el periodo de propagación. El desempeño clínico del medio TAN se estimó tomando como referencia el CITOSWAB® VTM, en 30 exudados nasofaríngeos colectados para diagnóstico de la infección por SARS-CoV-2. Resultados: El VZk preservó su infectividad a diluciones del inóculo ≥ 10-2, independientemente del tiempo de contacto. La sensibilidad y especificidad clínica del medio TAN para el diagnóstico de SARS-CoV-2 fueron del 100 %, respectivamente. Conclusiones: Los resultados sugieren que muestras clínicas positivas a VZk en diluciones ≤ 10-1 del medio TAN pueden ser manipuladas de forma segura, lo que pudiera aplicarse potencialmente al diagnóstico molecular del SARS-CoV-2.

ABSTRACT Introduction: Collection media of clinical samples with the capacity to denature viruses reduce the risk of contagion during transportation and processing. Objective: To use the nucleic acids transport media (NATM) in nasopharyngeal swab samples collected for the diagnosis of SARS-CoV-2. Methods: An experimental study was conducted to demonstrate the medium capacity to inactivate viral infectivity. Zika virus (ZIKV), of biosafety level 2, was used as an enveloped virus model. The clinical performance of the NATM for the diagnosis of SARS-CoV-2 was evaluated. A ZIKV strain propagated in the Vero cell line was used and, prior to cells infection, ZIKV was in contact at different intervals (2; 15, and 30 min) with pure NATM; subsequently, serial dilutions (10-1-10-4) were performed. Viral inactivation was evaluated by RT-PCR in the supernatant and the collected cells when the propagation period was completed. CITOSWAB® VTM was used as reference to estimate the clinical performance of the NATM in 30 nasopharyngeal swabs collected for the diagnosis of SARS-CoV-2 infection. Results: ZIKV remained infectious at inoculum dilutions of ≥ 10-2, regardless of contact time. Clinical specificity and sensitivity of the NATM for the diagnosis of SARS-CoV-2 were 100%, respectively. Conclusions: Results suggest that ZIKV positive clinical samples at dilutions ≤ 10-1 of the NATM can be safely handled, which could potentially be applied to the molecular diagnosis of SARS-CoV-2.

Subcutaneous allergen immunotherapy for asthma: A randomized, double-blind, placebo-controlled study with a standardized Blomia tropicalis vaccine.

BACKGROUND: Sensitization to Blomia tropicalis (Bt) is very frequent in the tropics, and particularly in Cuba, being a significant cause of allergic asthma. Allergen immunotherapy (AIT) with Bt can be a therapeutic option, however, placebo-controlled clinical trials have not been reported. OBJECTIVE: To assess the therapeutic effect and safety of AIT for asthma using a standardized allergen vaccine of B. tropicalis by subcutaneous route, in allergic asthmatic patients exposed and sensitized to this mite species. METHODS: A double-blind, placebo-controlled Phase II trial was conducted in 35 adults (18 with treatment and 17 with placebo), with mild to moderate asthma, predominantly sensitized to Bt. AIT was administered subcutaneously in increasing doses from 4 to 6000 Biological Units using a locally manufactured standardized extract (BIOCEN, Cuba). Patient assessment was performed using symptom-medication score (SMS), peak expiratory flow and skin reactivity relative to Histamine as measured by skin prick test (SPT). RESULTS: The 12-month treatment achieved a significant (p < 0.001) decrease of SMS. Symptom score showed only 41% (CI: 26-61) of placebo values, whereas medication was 34.5% (22.4%-63.3%). Treatment was regarded clinically effective in 67% of patients (OR 32; 95%CI: 17 to 102). The effect size on symptoms and medication was higher than has been reported with equivalent allergen dosages of D. pteronyssinus and D. siboney in Cuban asthmatic patients. Skin reactivity to Bt was also significantly reduced (p = 0.0001), increasing 148-fold the allergen threshold to elicit a positive skin test. This desensitization effect was specific to Bt and did not modify the reactivity to Dermatophagoides. The change of specific skin reactivity was significantly (p < 0.05) correlated to clinical improvement. All adverse events were local with a frequency of 2.4% of injections. CONCLUSIONS: Subcutaneous AIT with Blomia tropicalis was effective and safe in asthmatic adults exposed and sensitized to this mite species in a tropical environment. TRIAL REGISTRATION: Cuban Public Registry of Clinical Trials: RPCEC00000026 (WHO International Clinical Trial Registry Platform ICTRP).

Remote induction of cellular immune response in mice by anti-meningococcal nanocochleates - nanoproteoliposomes.

New adjuvant formulations, based on proteoliposomes <40 nm and cochleates <100 nm, without Al(OH)3 adjuvant, were evaluated regarding their ability to generate Th1 immune response through a Delayed -Type Hypersensitivity Test, at the mouse model, by using a Neisseria meningitidis B protein complex as antigen. The formulations were administered by intramuscular (IM) (2 inoculations - at baseline and after 14 days) and intranasal (IN) (3 inoculations at 7 days) immunization pathways. All IM immunized groups were able to induce similar response to these formulations as well as to VA-MENGOC-BC® vaccine - containing Al(OH)3 adjuvant (used as positive control of the trial). In all groups, the induced inflammation (IP) rate was statistically higher than in the negative control group (CN) (p < 0.05). Immunogenicity, measured by HSR and CD4+ lymphocyte increase was equivalent to the control vaccine and most important, granuloma reactogenicity at the site of injection was eliminated, fact demonstrated by histological study. All groups of animals immunized by IN route showed HSR reactions and statistically significant differences with respect to the CN group. However, IP values were lower, with statistical differences (p < 0.05) for the same adjuvant formulation IM administered, except the AIF2-nCh formulation that generated statistically similar induction (p > 0.05) by both immunization pathways, suggesting it to be the best candidate for the next IN trial. Proteoliposome and cochleate formulations tested were able to mount potent Th-1 immune response, equivalent to the original vaccine formulation, with the advantage of less reactogenicity in the site of the injection, caused by the toxicity of Al(OH)3 adjuvant gel.

Is peanut causing food allergy in Cuba? Preliminary assessment of allergic sensitization and IgE specificity profile to peanut allergens in Cuban allergic patients.

BACKGROUND: Peanut allergy is increasing at an alarming pace in developed countries. Peanut (Arachis hypogaea) is a common food in Cuba. Nevertheless, reported values of sensitization and symptom severity are usually low. As our objective, we carried out an evaluation of allergic sensitivity to perform an assessment of allergic sensitization and IgE specificity profile to peanut allergens in Cuban allergic patients. METHODS: The Skin Prick Test (SPT) was performed for each patient, using two glycerinated allergenic extracts, prepared from raw or roasted peanuts. Overall, 316 food allergic patients (159 adults and 157 children) attending allergy services at four hospitals in Havana were included, as well as 303 adult non- allergic volunteers. The IgE binding profile of 26 selected SPT positive patients was further analyzed by immunoblotting. RESULTS: The prevalence of sensitization to peanut was 4.6% in general adult population, whereas in adult food-allergic patients it was 18.6%. Prevalence rates were even greater in food allergic children achieving 25.8%. Sensitization frequencies were apparently greater for roasted, as compared to raw peanuts, although the difference was not significant (p> 0.05, Mc Nemar's). IgE binding was shown mostly by the 15 and 17 kDa bands, tentatively identified as the major allergens Ara h 2 and Ara h 6. The IgG4 binding profile was similar to IgE, although with more prominence of the bands at 37 and 28 KDa, corresponding to an Ara h 3 fragment and Peanut Agglutinin. DISCUSSION: The study estimated a relatively high prevalence of peanut sensitization in population. Data reported here suggest that IgE sensitization in Cuban patients is focused mostly on MW bands corresponding to the major allergens Ara h 6 and Ara h 2. CONCLUSIONS: Sensitization to peanut allergen is indeed relatively frequent in Cuba. The IgE profile is congruent to a sensitization pattern by ingestion of roasted peanuts and is directed to well-known major allergens.

[Sensitivity and specificity of prick skin test with two concentrations of standardized extract of Culex quinquefasciatus in allergic children]. / Sensibilidad y especificidad de la prueba cutánea por punción con dos concentraciones del extracto estandarizado de Culex quinquefasciatus en niños alérgicos.

BACKGROUND: Diagnostic options for immune reactions to mosquito bites are limited. In Cuba, IgE-mediated reactions are frequently related to Culex quinquefasciatus bite. OBJECTIVE: To determine the sensitivity and specificity of skin prick test with two doses of standardized extract in nitrogen protein units (PNU of Culex quinquefasciatus (BIOCEN, Cuba). MATERIAL AND METHOD: An analytical study was conducted on 100 children between 2 and 15 years old. Fifty atopic patients with a history of allergy to mosquito bite and positive specific serum IgE Culex quinquefasciatus and fifty atopic patients without a history of allergy to mosquito bite and negative specific serum IgE to Culex quinquefasciatus. Skin prick tests (SPT) were performed by duplicates on the forearms of the patients. Investigated doses were 100 PNU/mL and 10 PNU/mL. RESULTS: SPT with the highest concentration obtained a mean wheal size of 22.09 mm2 and for lower doses of 8.09 mm2, a statistically significant difference (p=0.001, Student's t test). Positive skin test correlated in 100% of patients with the presence of specific IgE. Testing with both doses showed a 94% of specificity and 88% of sensitivity. CONCLUSION: The diagnostic accuracy of SPT using both doses of standardized extract was similar, which justifies its use for diagnosis of sensitization to Culex quinquefasciatus in patients with symptoms of allergy to mosquito bite.

Antecedentes: las opciones diagnósticas de las reacciones inmunológicas a la picadura del mosquito son limitadas. En Cuba, las reacciones mediadas por IgE más frecuentes son por picadura de Culex quinquefasciatus. Objetivo: determinar la sensibilidad y especificidad de la prueba cutánea por punción con dos dosis del extracto estandarizado en unidades de nitrógeno proteico (UNP) de Culex quinquefasciatus (BIOCEN, Cuba). Material y método: estudio analítico efectuado en 100 niños entre 2 y 15 años de edad: 50 pacientes atópicos con antecedentes de alergia a la picadura de mosquito e IgE sérica específica positiva a Culex quinquefasciatus y 50 pacientes atópicos sin antecedentes de alergia a la picadura de mosquito e IgE sérica específica negativa a Culex quinquefasciatus. La prueba cutánea por punción se realizó por duplicado en los antebrazos de los pacientes. Las dosis investigadas fueron 100 y 10 UNP/mL. Resultados: en la prueba cutánea por punción con el extracto de mayor concentración se obtuvo un tamaño del área del habón de 22.09 mm2 y con la menor concentración de 8.19 mm2; una diferencia estadísticamente significativa (p=0.001, prueba t de Student). La prueba cutánea positiva se correlacionó en el 100% de los pacientes con la existencia de IgE específica. La prueba con ambas dosis mostró 94% de especificidad y 88% de sensibilidad. Conclusión: la alta coincidencia en el resultado de la prueba cutánea nos muestra que puede sustituirse la concentración del extracto a 100 UNP/mL por la de menor concentración, sin perder confiabilidad en el diagnóstico de sensibilización al mosquito Culex quinquefasciatus, utilizando ese método in vivo.

Prevalencia de sensibilización a ácaros, trigo, soya y levadura en trabajadores de cinco panaderías de La Habana, Cuba / Prevalence of sensitization to mites, wheat, soy and yeast in five workers of bakeries of Havana, Cuba

Introducción: Los panaderos son un grupo profesional en riesgo de desarrollar enfermedades alérgicas de origen ocupacional. Son varios los alérgenos que pueden sensibilizarlos, especialmente la harina de trigo y los ácaros, que encuentran en este ambiente laboral condiciones favorables de hábitat. Objetivo: Identificar la frecuencia de sensibilización a ácaros y alérgenos ocupacionales en un grupo de 80 trabajadores de panaderías de La Habana , y determinar la prevalencia de enfermedades alérgicas en este grupo laboral. Material y método: Se realizó un estudio analítico de corte transversal. La muestra se constituyó con 80 trabajadores de 5 panaderías de La Habana. A todos se les confeccionó una historia clínica alergológica y laboral, y se les realizaron pruebas cutáneas por punción con extractos de ácaros representantes del género Dermatophagoides y de las familias Acaridae y Echimyopodidae , y con extractos de alimentos de soya, harina de trigo y levadura, para determinar la sensibilidad a los mismos. Resultados: El 46,3 por ciento reportó alguna enfermedad alérgica y el 18,8 por ciento sintomatología actual, la mayoría de tipo respiratoria. El 86,3 por ciento de los trabajadores tuvo pruebas cutáneas positivas, mostrando al menos sensibilización a 1 o más alérgenos. La mayor positividad se encontró al ácaro D. farinae (61,3 por ciento) y el mayor tamaño del habón (media de 4,6 mm ). El 42,5 por ciento del total de trabajadores mostró sensibilización al trigo. Se determinó una asociación significativa (p<0,05) entre la reacción cutánea al trigo, la levadura y la soya con los ácaros de almacén y del polvo doméstico. Conclusiones: Existe elevada prevalencia de enfermedades respiratorias y sensibilización a ácaros y a la harina de trigo entre los panaderos, lo cual constituye un factor de riesgo a tener en cuenta para su seguridad ocupacional(AU)

[Dust mites as occupational allergens in two bakeries of La Habana, Cuba]. / Ácaros del polvo como alérgenos ocupacionales en dos panaderías de La Habana, Cuba.

BACKGROUND: Occupational allergies are becoming more frequent. The allergens present in the working environment of bakeries, such as mites, are not well identified despite being known risk factors of respiratory diseases. OBJECTIVES: To isolate and identify the species of mites present in two bakeries in La Habana, Cuba, with high sensitization of mites on their workers. MATERIAL AND METHOD: A descriptive study was done in which samples were taken by tripled from potential sources of mites in bakeries -as flourin use, spills of wheat on the floors, wheat flour stored in sealed bags, sugar, yeast, granulated baker- that were processed, according to the method of flotation of Hart and Fain (1987) to isolate, identify and count the mites present. RESULTS: Mites were found in samples of wheat flourin use, spills on the floorsand in the wheat flourstored in sealed bags. The species identified were Blomia tropicalis (70%), Tyrophagus putrescentiae (20%) and to a lesser degree Dermatophagoides pteronyssinus and Dermatophagoides siboney. CONCLUSIONS: There is a high exposure to house dust mites, particularly to store mites, which constitute a risk factor of occupational allergy to consider.

Antecedentes: las alergias ocupacionales son cada vez más frecuentes. Los alergenos del ambiente laboral de panaderías, como los ácaros, no están bien identificados a pesar de ser factores de riesgo conocidos de enfermedades respiratorias. Objetivos: aislar e identificarlas especies de ácaros en dos panaderías de La Habana, Cuba, con alta sensibilización a ácaros en sus trabajadores. Material y método: estudio descriptivo en el que se tomaron muestras por triplicado de las posibles fuentes de ácaros en las panaderías ­como harina de trigo en uso, derrames de harina de trigo en los pisos, harina de trigo almacenada en sacos sellados, azúcar, levadura panadera granulada­ que fueron procesadas, según el método de flotación de Hart and Fain (1987) para aislar, identificar y contar los ácaros presentes. Resultados: se encontraron ácaros en las muestras de harina de trigo en uso, en los derrames de ésta en los pisos y en la harina de trigo almacenada en sacos sellados. Las especies identificadas fueron Blomia tropicalis (70%), Tyrophagus putrescentiae (20%) y en mucho menor grado Dermatophagoides pteronyssinus y Dermatophagoides siboney. Conclusiones: existe elevada exposición a ácaros del polvo doméstico, particularmente a ácaros de almacén, en las panaderías analizadas, lo que constituye un factor de riesgo de alergia ocupacional a considerar.

[Sensitization to mites and occupational allergens in bakery workers of la habana, cuba]. / Sensibilización a ácaros y alergenos ocupacionales en trabajadores de una panadería de La Habana, Cuba.

BACKGROUND: Sensitization to allergens at the workplace is an essential factor for the development of occupational respiratory diseases. OBJETIVE: To determine the frequency of sensitization to mites and other occupational allergens in bakery workers, by skin prick test (PCP). METHODS: In this unpaired case-control study were included 17 workers, mean age 34 years (range 18-55), and the control group 14 patients, mean age 32 years (range 22-47), both predominantly male 76 % and 85 % respectively. Each subject had a history and physical examination, and underwent skin testing with allergenic extracts. RESULTS: All investigated subjects showed at least a positive response to two allergens in the SPT. The highest percentage of sensitization in bakers corresponded to Acarus siro and Dermatophagoides Siboney with 82.35% each, followed by Blomia tropicalis, D. farinae, Lepydoglyphus destructor and Tyrophagus putrescientae. The lowest positivity corresponded to D. pteronyssinus (47%), different to that found in the control group where this was the predominant mite. The highest wheal diameter values were for the storage mites A. siro and T. putrescientae in the study group and D. farinae and B. tropicalis in the control group. Sensitization was found to wheat flour in 82 % of these bakers. CONCLUSIONS: There is a high sensitization to house dust mites, and particularly to the storage mites and as to allergens from wheat flour to bakers, this represents a risk factor to be considered for occupational safety.

[Evaluation of the efficacy of a Soybean Allergenic Extract in the Diagnosis of Immediate Hypersensitivity]. / Evaluación de la eficacia de un extracto alergénico de soya para el diagnóstico de hipersensibilidad inmediata.

BACKGROUND: Allergy to soybean has an increasing tendency due to the high consumption of soybean as a basic food resource available in poor countries, and also for being so widely used for commercial purposes. This fact demands the development of safer and cheaper allergenic extracts for skin prick tests, with better diagnostic accuracy. OBJETIVE: To evaluate the safety and diagnostic accuracy of a soybean¥s extract for skin prick test to diagnose food allergy. METHODS: In this observational and prospective research 60 individuals were studied, 30 of them with the clinical diagnosis of soybean¥s allergy and 30 controls. Skin prick tests were performed with both, shell and soybean grain extracts (0,1mg/mL and 1mg/mL), and specificity, sensitivity and accuracy were calculated. RESULTS: Sixty percent of all patients with soybean allergy showed a positive result to soybean grain extract. On the other hand, the patients in the control group had all negative results for both allergen extract concentrations (p < 0.05). All extracts¥ dilutions have 100% specificity. We observed that the soybean grain extract at 1 mg/mL was sensitive in 60%, specific in 100% and effective in 80% for soybean allergy diagnosis. CONCLUSIONS: The soybean grain extract has both safety and diagnostic accuracy for the diagnosis of food allergy to soybean at the higher concentration.

[Sensitization to three house dust mites in a children allergic population of cuba]. / Sensibilización a tres ácaros domésticos en una población infantil alérgica de Cuba.

BACKGROUND: Allergic diseases constitute a worldwide health problem and mites are among the main etiological agents. OBJECTIVE: To characterize the sensitization to the mites Dermatophagoides pteronyssinus, Dermatophagoides siboney, and Blomia tropicalis, by skin tests in a children allergic sample from Cuba. METHODS: This is a descriptive transversal investigation that included 103 allergic children, with ages ranging from 3 to 15 years, who underwent skin prick tests with D. pteronyssinus, D. siboney, and B. tropicalis allergenic extracts. For the analysis of the results, sex, place of residence and degree of exposure to house dust were considered. RESULTS: The greater sensitization was to D. pteronyssinus (36,9%), followed by D. siboney (35%) and B. tropicalis (33%). The greater geometric mean of the wheal diameter was 5,14 mm for D. pteronyssinus (IC95%: 4.52-5.76 mm); 4.82 mm for D. siboney (IC95%: 4.22-5.43 mm) and 4.25 mm for B. tropicalis (IC95%: 3.93-4.58 mm). Fifty six children (54.3%) were not sensitive to none of the three mites. In 45.7% we found sensitization at least to one mite, and 21.4% were sensitive to the three mites. There were no significant differences (p >0.05) in the sensitization according to sex, place of residence and degree of exposure to house dust. The percentage of sensitive patients with rhinitis plus asthma was more significant (p < 0.001), and in them, the geometric mean of the wheal diameter was significant for D. pteronyssinus (p=0.028) and D. siboney (p=0. 027). CONCLUSIONS: A third of our studied child population, residing in a non-industrialized tropical area, presented sensitization to one or some of the three tested mites. There was a different pattern of sensitization with mites in relation to gender. Patients with asthma plus rhinitis showed more sensitization concerning the number and intensity of the skin tests.

[Relative potency of allergenic extracts from mites in patients with asthma and allergic rhinitis]. / Potencia relativa de extractos alergénicos de ácaros en pacientes con asma y rinitis alérgicas.

BACKGROUND: Skin tests for specific diagnosis of allergies require high quality extracts, which can be measured by the determination of allergenic potency, utilizing different concentrations of extracts from a manufacturer. OBJETIVE: To compare allergenic mite extracts manufactured by laboratories in Spain, Argentina, and Cuba by skin prick test response. METHODS: A cutaneous puncture was performed on 56 patients aged 2 to 15 years with asthma and allergic rhinitis with extracts of Dermatophagoides pteronyssinus (Dp), Dermatophagoides farinae (Df), Dermatophagoides siboney (Ds) and Blomia tropicalis (Bt) produced by DIATER (Argentina), ALK- AbellÛ (Spain) and BIOCEN (Cuba). RESULTS: In 84.6% of patients there was an association of symptoms with seasonal changes and house dust exposure. The diameter of wheals from ALK allergen extract was larger than extracts from other sources, but without any significant difference (p > 0.05). The ratio between wheals and allergen concentration with BIOCEN products showed lineal dependence between the diameter averages and the concentration logarithm, ranging from 4000 to 100 000 UB/mL. The skin prick tests with diameters =3mm showed a larger proportion of Dp and Df from ALK in comparison to BIOCEN and DIATER. CONCLUSIONS: We found that dust mite extracts produced and standardized by DIATER, ALK-Abello and BIOCEN were similar with respect to allergenic potency.

[Skin prick tests with standardized extracts of mites of different precedence in patients with asthma and allergic rhinitis]. / Pruebas cutáneas de punción con extractos estandarizados de ácaros de diferente procedencia en pacientes con asma y rinitis alérgica.

BACKGROUND: House dust mites are important airborne allergens worldwide, particularly in the tropical environment. OBJECTIVE: To assess sensitization of allergic patients to different mite species in the Cuban city of Camaguey; as well as to compare standardized allergen extracts from different sources by skin prick tests. PATIENTS AND METHOD: Skin prick tests were performed in 60 patients with asthma and/or allergic rhinitis and in 60 non-allergic volunteers, ranging from 2 to 76 years old. In both groups, Diater-Prick lancets were used, together with Valergen extracts (Biocen, Cuba) at 20,000 BU/mL and Diater extracts (Argentina) at 50,000 UBE/PNU/mL. RESULTS: The highest values of sensitization prevalence using Diater extracts were seen in Dermatophagoides pteronyssinus (Dp), Dermatophagoides farinae (Df), and Blomia tropicalis (Bt) in allergic patients and in non-allergic controls. Diagnostic sensitivity values were: Dp, 79; Df, 84; Bt, 84 and B. kulagini, 83%. Specificity varied from 72 to 85%. On the other hand, with Biocen extracts, the highest positivity was noted in Dp and D. siboney (Ds). Sensitivity values were 78% (Dp); 78% (Ds) and 82% (BT). Specificity values ranged from 79 to 82%. CONCLUSIONS: The standardized allergen extracts from the assessed laboratories induced similar values of sensitivity and specificity.

Sensibilización a tres especies de ácaros en pacientes alérgicos de lazona costera de la ciudad de La Habana

Antecedentes: en diferentes estudios se ha reportado la sensibilización de pacientes a los ácaros Dermatophagoides pteronyssinus,Dermatophagoides siboney y Blomia tropicalis (alergénicos del polvo doméstico en Cuba). Objetivo: determinar la sensibilización a Dermatophagoides pteronyssinus, Dermatophagoides siboney y Blomia tropicalis en pacientesde la costa norte de la ciudad de La Habana, Cuba. Pacientes y métodos: se seleccionaron 210 pacientes alérgicos, clasificados en dos grupos (de 1 a 14 y de 15 a 55 años de edad).Se realizaron pruebas por punción cutánea con extractos alergénicos estandarizados VALERGEN-BT (B. tropicalis), VALERGENDS(D. siboney) y VALERGEN-DP (D. pteronyssinus) de producción nacional (BIOCEN). La prueba se consideró positiva cuando el diámetro del habón fue mayor o igual a 3 mm. Resultados: ambos grupos mostraron mayor sensibilización para D. pteronyssinus (>78 porciento), mientras que para los otros ácaros fue por debajo de 60 porciento. En los pacientes mayores de 14 años la sensibilización fue aparentemente más alta, aunque no significativa estadísticamente (p > 0.05). Sin embargo, la reactividad cutánea en ese grupo fue significativamente mayor (p < 0.05) para los tres alergenos. Inusitadamente, el tamaño promedio del habón fue superior (p < 0.05) para B. tropicalis.Conclusiones: aunque la sensibilización para D. pteronyssinus fue mayor, B. tropicalis mostró ser un aeroalérgeno de importancia por su mayor reactividad cutánea y más de 50 porciento de sensibilización. En los pobladores de la ciudad de La Habana sería recomendablerealizar la prueba cutánea por punción con los tres extractos de ácaros, simultáneamente, y combinarlos en la inmunoterapia específica(AU)

Background: Sensitization to three allergic mite species Dermatophagoides pteronyssinus, Dermatophagoides siboney and Blomia tropicalis) from house dust in Cuba has been reported in different studies. Objective: To assess allergic sensitization to these mites in a north coast area of Havana city.Patients and methods: A total of 210 allergic patients were selected, classified in two groups: from 1 to 14 years, and from 15 to 55 years. Skin Prick Test (SPT) was performed on all patients using standardized allergenic extracts VALERGEN-BT (B. tropicalis),VALERGEN-DS (D. siboney) and VALERGEN-DP (D. pteronyssinus) manufactured by BIOCEN, Cuba. The test was considered positive when the average wheal diameter was greater or equal to 3 mm. Results: Both groups showed higher sensitization to D. pteronyssinus (>78 percent), while for the remaining mites it was below 60 percent. In patients older than 14 years, the sensitization was apparently higher, although not statistically significant (p>0.05). Nevertheless, theskin reactivity in this group was significantly greater (p <0.05) for the three allergens. Unusually, mean wheal size in both groups was significantly superior toward B. tropicalis (p <0.05).Conclusions: In spite of being D. pteronyssinus the mite showing the highest sensitization, Blomia tropicalis showed to be also an important aeroallergen with more than 50 percent sensitization and greater skin reactivity. Therefore, in our population it would be advisable to perform SPT with the three mites extracts, simultaneously and to combine it in allergen-specific immunotherapy(AU)

Sensibilización a dermatophagoides pteronyssinus, dermatophagoides siboney y blomia tropicalis en niños de tres consultorios / Sensitization to dermatophagoides pteronyssinus, dermatophagoides siboney and blomia tropicalis in children from three family physician’s offices

La morbilidad de las enfermedades alérgicas mediadas por el anticuerpo IgE, se ha incrementado en los últimos 40 años y además, se han identificado a los ácaros domésticos como sus principales agentes causales. En Cuba, los ácaros más frecuentemente son: Dermatophagoides pteronyssinus (D. pteronyssinus), Dermatophagoides siboney (D. siboney) y Blomia tropicalis (B. tropicalis). En este estudio investigamos si la sensibilización a estos ácaros constituye un problema de salud en nuestra población infantil y su relación con la exposición al polvo doméstico. Se seleccionaron 103 niños alérgicos del pueblo de Guatao, que se clasificaron según su grado de exposición al polvo doméstico. A todos se les realizó la prueba por punción cutánea por duplicado en ambos antebrazos y se utilizaron los extractos alergénicos estandarizados VALERGEN-BT Ò (Blomia tropicalis), VALERGEN-DS Ò (Dermatophagoides siboney) y VALERGEN-DP Ò (Dermatophagoides pteronyssinus), todos de producción nacional en el Centro Nacional de Biopreparados. La sensibilización fue mayor de forma significativa (p<0,01) para todos los ácaros en los pacientes con mayor exposición al polvo doméstico con respecto a los de menor exposición. Además, registramos una sensibilización mayor a los ácaros del género Dermatophagoides, especialmente para el D. pteronyssinus. El extracto D. pteronyssinus provocó un tamaño medio del habón mayor que los otros productos en los pacientes positivos de ambos grupos (p<0,04), por lo que concluimos que la mayor exposición de los pacientes al polvo doméstico está relacionada con una mayor sensibilización a los ácaros

Sensibilización a dermatophagoides pteronyssinus, dermatophagoides siboney y blomia tropicalis en niños de tres consultorios / Sensitization to dermatophagoides pteronyssinus, dermatophagoides siboney and blomia tropicalis in children from three family physicians offices

La morbilidad de las enfermedades alérgicas mediadas por el anticuerpo IgE, se ha incrementado en los últimos 40 años y además, se han identificado a los ácaros domésticos como sus principales agentes causales. En Cuba, los ácaros más frecuentemente son: Dermatophagoides pteronyssinus (D. pteronyssinus), Dermatophagoides siboney (D. siboney) y Blomia tropicalis (B. tropicalis). En este estudio investigamos si la sensibilización a estos ácaros constituye un problema de salud en nuestra población infantil y su relación con la exposición al polvo doméstico. Se seleccionaron 103 niños alérgicos del pueblo de Guatao, que se clasificaron según su grado de exposición al polvo doméstico. A todos se les realizó la prueba por punción cutánea por duplicado en ambos antebrazos y se utilizaron los extractos alergénicos estandarizados VALERGEN-BT Ò (Blomia tropicalis), VALERGEN-DS Ò (Dermatophagoides siboney) y VALERGEN-DP Ò (Dermatophagoides pteronyssinus), todos de producción nacional en el Centro Nacional de Biopreparados. La sensibilización fue mayor de forma significativa (p<0,01) para todos los ácaros en los pacientes con mayor exposición al polvo doméstico con respecto a los de menor exposición. Además, registramos una sensibilización mayor a los ácaros del género Dermatophagoides, especialmente para el D. pteronyssinus. El extracto D. pteronyssinus provocó un tamaño medio del habón mayor que los otros productos en los pacientes positivos de ambos grupos (p<0,04), por lo que concluimos que la mayor exposición de los pacientes al polvo doméstico está relacionada con una mayor sensibilización a los ácaros(AU)

Prevalencia de la sensibilización a tres ácaros domésticos en la población infantil alérgica de un consultorio médico / Prevalence of sensitization to three house dust mites in the allergic infantile population of a family physician's office

Se realizó un estudio con el objetivo de investigar si la sensibilización a estos ácaros ( Dermatophagoides pteronyssinus [ Dp ], Dermatophagoides siboney [ Ds ] y Blomia tropicalis [ Bt ] ) constituye un problema de salud en nuestra población infantil, pues el estudio de los problemas alérgicos ha identificado a los ácaros domésticos como los principales agentes causales de asma y otras afecciones. Se seleccionaron 32 niños alérgicos de nuestro consultorio que se clasificaron según su grado de exposición al polvo doméstico. A todos se les realizó la prueba por punción cutánea en el brazo derecho, y se utilizaron 3 extractos alergénicos estandarizados Valergen Ò ( Blomia tropicalis, Dermatophagoides siboney y Dermatophagoides pteronyssinus ) de producción nacional (BIOCEN). La prevalencia de la sensibilización fue mayor de forma significativa (p<0,05) para todos los ácaros en los pacientes con mayor exposición al polvo doméstico con respecto a los de menor exposición. Para los ácaros del género Dermatophagoides se obtuvo una sensibilización mayor. El extracto de Dp provocó un tamaño medio del habón mayor que los otros productos(AU)

Prevalencia de la sensibilización a tres ácaros domésticos en la población infantil alérgica de un consultorio médico / Prevalence of sensitization to three house dust mites in the allergic infantile population of a family physician's office

Se realizó un estudio con el objetivo de investigar si la sensibilización a estos ácaros ( Dermatophagoides pteronyssinus [ Dp ], Dermatophagoides siboney [ Ds ] y Blomia tropicalis [ Bt ] ) constituye un problema de salud en nuestra población infantil, pues el estudio de los problemas alérgicos ha identificado a los ácaros domésticos como los principales agentes causales de asma y otras afecciones. Se seleccionaron 32 niños alérgicos de nuestro consultorio que se clasificaron según su grado de exposición al polvo doméstico. A todos se les realizó la prueba por punción cutánea en el brazo derecho, y se utilizaron 3 extractos alergénicos estandarizados Valergen Ò ( Blomia tropicalis, Dermatophagoides siboney y Dermatophagoides pteronyssinus ) de producción nacional (BIOCEN). La prevalencia de la sensibilización fue mayor de forma significativa (p<0,05) para todos los ácaros en los pacientes con mayor exposición al polvo doméstico con respecto a los de menor exposición. Para los ácaros del género Dermatophagoides se obtuvo una sensibilización mayor. El extracto de Dp provocó un tamaño medio del habón mayor que los otros productos.

A study was conducted aimed at investigating if the sensitization to these dust mites (Dermatophagoides pteronyssinus [Dp], Dermatophagoides siboney [Ds] and Blomia tropicalis [Bt] ) is a health problem in our infantile population, since the study of the allergic problems has identified the house dust mites as the main agents causing asthma and other affections. 32 allergic children of our office were selected and classified according to their degree of exposure to house dust. All of them underwent the skin test in the right arm. 3 standardized allergenic extracts ValergenÒ (Blomia tropicalis, Dermatophagoides siboney y Dermatophagoides pteronyssinus) of national production (BIOCEN) were used. The prevalence of sensitization was significantly higher (p<0.05) for all the dust mites in patients with a greater exposure to house dust compared with those with lower exposure to it. A higher sensitization was attained for the dust mites of the genus Dermatophagoides. The extract of Dp produced a wheal with a mean size greater than the one caused by other products.

[Comparison of two lancets in the skin prick test]. / Comparación de dos lancetas en la prueba cutanea por punción.

BACKGROUND: The skin prick test is used to diagnose the allergic sensitization. Its results depend upon several factors, such as the lancet type. In Cuba, the most frequently used are: ALK lancet and blood lancet. OBJECTIVE: To compare these two lancets regarding the size of the wheal, precision, sensitivity and specificity of the skin prick test and, finally, the preference of the patients to one of them. PATIENTS AND METHODS: The study was performed in 60 allergic patients, aged 15-50 years, seen at the allergy service of Hospital Universitario Clínico Quirúrgico General Calixto García. The skin prick test was performed on the forearm of all patients included, using both lancet types. A negative control (diluent solution) was applied, together with a 54.3 mmol/L histamine solution in five replicates. RESULTS: The mean size of skin reaction to histamine was 6 mm, using a 1 mm single peak lancet (ALK), size was 6.5 mm when using blood lancet (significant difference p < 0.05). Precision, sensitivity and specificity of ALK lancet were 9.7, 100 and 100%, respectively. On the other hand, the respective values for blood lancet were 15.9, 96 and 87%. Of those studied, 27% presented mild pain and 3% moderate pain using the ALK lancet; while 25% showed mild pain and 10% moderate pain using the blood lancet. CONCLUSION: The ALK lancet showed more precision, sensitivity and specificity and it was preferred by the patients.

Respuesta IgE específica al ácaro Blomia tropicalis en pacientes cubanos / Answer specific IgE to the acarus Blomia tropicalis in Cuban patients

Se realizó un estudio analítico prospectivo y transversal de 84 pacientes atendidos en la consulta de alergia del Hospital Calixto García, en los cuales la prueba cutánea inmediata al extracto alergénico Blomia tropicalis fue positiva; los sueros de estos pacientes se utilizaron en los ensayos de determinación de anticuerpos IgE específicos y en la identificación de proteínas alergénicas en dicho extracto por medio de western blotting. Del total, 44 pacientes (55 por ciento) mostraron niveles de IgE específica mayores que 0,1 U y 17 pacientes, niveles mayores que 0,3 U. El asma bronquial y la rinitis fueron las patologías con mayores niveles de IgE específica. Sin embargo, los valores de IgE específica en general, fueron inferiores a los reportados para otros ácaros, a pesar de que la reactividad cutánea se comportó de una forma similar. Se determinó que los anticuerpos IgE específicos están mayormente dirigidos hacia los alergenos de peso molecular entre 13 y 15 kD(AU)