Weight Loss and Vitamin D Improve Hyporesponsiveness to Corticosteroids in Obese Asthma.

BACKGROUND AND OBJECTIVES: Obesity negatively impacts on the response of asthma patients to inhaled corticosteroids. The mechanisms underlying this impact are unknown. Objective: To demonstrate that the poor response to inhaled corticosteroids in obese asthma patients is associated with impaired anti-inflammatory activity of corticosteroids and vitamin D deficiency, both of which are improved by weight loss. METHODS: The study population comprised 23 obese asthma patients (OA) (18 females; median (IQR) age 56 [51-59] years), 14 nonobese asthma patients (NOA) (11 females; 53 [43-60] years), 15 obese patients (OP) (13 females; 47 [45-60] years), and 19 healthy controls (HC) (14 females; 43 [34-56] years). Ten OA and 11 OP were evaluated at baseline (V1) and 6 months after bariatric surgery (V2). Corticosteroid response was measured using dexamethasone-induced inhibition of peripheral blood mononuclear cell (PBMC) proliferation. Lung function and serum levels of leptin, adiponectin, and vitamin D were measured at V1 and V2. RESULTS: We found a reduced response to dexamethasone in PBMCs of OP and OA with respect to NOA and HC; this inversely correlated with the adiponectin/leptin ratio and vitamin D levels. Bariatric surgery improved corticosteroid responses in OP and OA and normalized the adiponectin/leptin ratio and vitamin D levels. Exposure of PBMCs to vitamin D potentiated the antiproliferative effects of corticosteroids. Dexamethasone and vitamin D induced similar MKP1 expression in OP and OA. CONCLUSION: The efficacy of weight loss to improve symptoms and lung function in OA may be due, at least in part, to the recovered anti-inflammatory effects of corticosteroids. Vitamin D deficiency may contribute to corticosteroid hyporesponsiveness in OA.

Improvement in Olfaction in Patients With CRSwNP and Severe Asthma Taking Anti-IgE and Anti-IL-5 Biologics: A Real-Life Study.

BACKGROUND AND OBJECTIVES: Chronic rhinosinusitis with nasal polyps (CRSwNP), which is characterized by partial loss of smell (hyposmia) or total loss of smell (anosmia), is commonly associated with asthma and/or nonsteroidal anti-inflammatory drug-exacerbated respiratory disease (N-ERD). CRSwNP worsens disease severity and quality of life. The objective of this real-world study was to determine whether biological treatments prescribed for severe asthma can improve olfaction in patients with CRSwNP. A further objective was to compare the improvement in in olfaction in N-ERD and non-N-ERD subgroups. METHODS: We performed a multicenter, noninterventional, retrospective, observational study of 206 patients with severe asthma and CRSwNP undergoing biological treatment (omalizumab, mepolizumab, benralizumab, or reslizumab). RESULTS: Olfaction improved after treatment with all 4 monoclonal antibodies (omalizumab [35.8%], mepolizumab [35.4%], reslizumab [35.7%], and benralizumab [39.1%]), with no differences between the groups. Olfaction was more likely to improve in patients with atopy, more frequent use of short-course systemic corticosteroids, and larger polyp size. The proportion of patients whose olfaction improved was similar between the N-ERD (37%) and non-N-ERD (35.7%) groups. CONCLUSIONS: This is the first real-world study to compare improvement in olfaction among patients undergoing long-term treatment with omalizumab, mepolizumab, reslizumab, or benralizumab for severe asthma and associated CRSwNP. Approximately 4 out of 10 patients reported a subjective improvement in olfaction (with nonsignificant differences between biologic drugs). No differences were found for improved olfaction between the N-ERD and non-N-ERD groups.

Exacerbations Among Patients With Asthma Are Largely Dependent on the Presence of Multimorbidity.

BACKGROUND AND OBJECTIVE: Comorbidities can influence asthma control and promote asthma exacerbations (AEs). However, the impact of multimorbidity in AEs, assessed based on long-term follow-up of patients with asthma of different degrees of severity, has received little attention in real-life conditions. To describe the epidemiological and clinical characteristics and predictors of AEs in patients who had presented at least 1 AE in the previous year in the MEchanism of Genesis and Evolution of Asthma (MEGA) cohort. METHODS: The work-up included a detailed clinical examination, pulmonary function testing, fractional exhaled nitric oxide (FeNO), blood counts, induced sputum, skin prick-tests, asthma questionnaires, and assessment of multimorbidity. The number of moderate-severe AEs in the preceding year was registered for each patient. RESULTS: The study population comprised 486 patients with asthma (23.7% mild, 35% moderate, 41.3% severe). Disease remained uncontrolled in 41.9%, and 47.3% presented ≥1 moderate-severe AE, with a mean (SD) annual exacerbation rate of 0.47 (0.91) vs 2.11 (2.82) in mild and severe asthma, respectively. Comorbidity was detected in 56.4% (66.6% among those with severe asthma). Bronchiectasis, chronic rhinosinusitis with nasal polyps, atopy, psychiatric illnesses, hyperlipidemia, and hypertension were significantly associated with AEs. No associations were found for FeNO, blood eosinophils, or total serum IgE. Sputum eosinophilia and a high-T2 inflammatory pattern were significantly associated with AEs. Multivariable regression analysis showed a significant association with asthma severity, uncontrolled disease, and low prebronchodilator FEV1/FVC. CONCLUSION: Our study revealed a high frequency of AE in the MEGA cohort. This was strongly associated with multimorbidity, asthma severity, poor asthma control, airflow obstruction, higher sputum eosinophils, and a very high-T2 inflammatory pattern.

Weight Loss and Vitamin D Improve Hyporesponsiveness to Corticosteroids in Obese Asthma

Background: Obesity negatively impacts on the response of asthma patients to inhaled corticosteroids. The mechanisms underlying this impact are unknown. Objective: To demonstrate that the poor response to inhaled corticosteroids in obese asthma patients is associated with impaired anti-inflammatory activity of corticosteroids and vitamin D deficiency, both of which are improved by weight loss. Methods: The study population comprised 23 obese asthma patients (OA) (18 females; median (IQR) age 56 [51-59] years), 14 nonobese asthma patients (NOA) (11 females; 53 [43-60] years), 15 obese patients (OP) (13 females; 47 [45-60] years), and 19 healthy controls (HC) (14 females; 43 [34-56] years). Ten OA and 11 OP were evaluated at baseline (V1) and 6 months after bariatric surgery (V2). Corticosteroid response was measured using dexamethasone-induced inhibition of peripheral blood mononuclear cell (PBMC) proliferation. Lung function and serum levels of leptin, adiponectin, and vitamin D were measured at V1 and V2. Results: We found a reduced response to dexamethasone in PBMCs of OP and OA with respect to NOA and HC; this inversely correlated with the adiponectin/leptin ratio and vitamin D levels. Bariatric surgery improved corticosteroid responses in OP and OA and normalized the adiponectin/leptin ratio and vitamin D levels. Exposure of PBMCs to vitamin D potentiated the antiproliferative effects of corticosteroids. Dexamethasone and vitamin D induced similar MKP1 expression in OP and OA. (AU)

Antecedentes: La obesidad tiene un impacto negativo en la respuesta del asma a los corticosteroides inhalados por mecanismos desconocidos. Objetivo: Demostrar que la mala respuesta a los corticosteroides inhalados en pacientes obesos asmáticos se asocia con una actividad antiinflamatoria alterada de los corticosteroides, así como también a la deficiencia de vitamina D, ambos mejorados por la pérdida de peso. Métodos: 23 obesos asmáticos (OA) (18 mujeres; mediana de edad [rango intercuartílico] 56 [51-59] años), 14 asmáticos no obesos (NOA) (11 mujeres; 53 [43-60] años), 15 obesos (O) (13 mujeres; 47 [45-60] años), y 19 controles sanos (HC) (14 mujeres; 43 [34-56] años) fueron incluidos. Se evaluaron 10 pacientes OA y 11 O al inicio (V1) y seis meses después (V2) de cirugía bariátrica. La respuesta a los corticosteroides se midió mediante la inhibición con dexametasona de la proliferación de células mononucleares de sangre periférica (PBMC). La función pulmonar, los niveles séricos de leptina, adiponectina y vitamina D se midieron en V1 y V2. Resultados: Encontramos una respuesta reducida a la dexametasona en PBMC de pacientes O y OA con respecto a los NOA y HC, que se correlacionó de forma inversamente proporcional con la relación adiponectina/leptina y los niveles de vitamina D. La cirugía bariátrica mejoró las respuestas de los corticosteroides en los grupos de pacientes O y OA, y normalizó la relación adiponectina/leptina y los niveles de vitamina D. La exposición de las PBMC a la vitamina D potenció los efectos antiproliferativos de los corticosteroides. La dexametasona y la vitamina D indujeron una expresión similar de MKP-1 en los pacientes O y OA. (AU)

Self-perception of olfactory dysfunction is associated with history of Traumatic Brain Injury: post-hoc analysis from the OLFACAT survey.

BACKGROUND: Traumatic brain injury (TBI) is one of the main causes of smell loss. However, epidemiological studies evaluating the incidence in general population are scarce. The aim of this analysis is to investigate the prevalence of TBI-induced olfactory dysfunction (OD) in a general-based population study. METHODOLOGY: A cross-sectional population-based survey was distributed to general population (260,000 households) through the newspaper. The survey included four microencapsulated odorants (smell test) to assess smell loss and two self-administered questionnaires (odour description and epidemiology/health status). Participants were divided into two groups, with or without a history of TBI. RESULTS: From 10,783 returned surveys, 9,348 were analysed. The survey profile was a 43-year old woman with medium-high educational level, living in a city. The overall prevalence of TBI was 5% (N=464, 44.5±14.1 years old, 57% females). Recorded causes of TBI were traffic, domestic, or work accidents. Subjects with TBI reported a poorer subjective smell self-perception compared to non-TBI participants, and a decreases ability to identify mercaptan (odour added to gas used in cities). Although, using the smell test, both groups showed similar smell capacities. CONCLUSIONS: Subjects with TBI history report a higher frequency of self-perceived OD, and a decrease ability to smell the odour added to domestic gas. Having said that, the prevalence of OD, according to the smell test, was similar in both groups.

Effects of Rupatadine on Platelet- Activating Factor-Induced Human Mast Cell Degranulation Compared With Desloratadine and Levocetirizine (The MASPAF Study).

BACKGROUND AND OBJECTIVE: Platelet-activating factor (PAF) is a lipid mediator involved in the pathophysiology of several allergic diseases, for example, in the amplification of mast cell (MC) activation in anaphylaxis. Rupatadine is an antihistamine with a demonstrated anti-PAF effect, although its capacity to inhibit PAF-induced MC degranulation has not been fully evaluated. Objectives: To compare the ability of rupatadine to inhibit PAF-induced MC degranulation with that of desloratadine and levocetirizine and to confirm the dual anti-H1 and anti-PAF activity of rupatadine. METHODS: The human MC line LAD2 and primary MCs (human lung tissue MCs [hLMCs]) were used. MC mediator release was evaluated using the b-hexosaminidase and histamine release assay. The effects of rupatadine (H1 antagonist + PAF receptor antagonist), desloratadine, and levocetirizine (H1 antagonists) on LAD2 and hLMCs were compared. The PAF receptor antagonists WEB2086, BN52021, and CV6209 were also tested. PAF receptor protein expression was evaluated in both LAD2 and hLMCs. RESULTS: CV6209 and rupatadine inhibited PAF-induced MC degranulation in both LAD2 and hLMCs. In LAD2, rupatadine (5 and 10 µM) and levocetirizine (5 µM), but not desloratadine, inhibited PAF-induced b-hexosaminidase release. Rupatadine (1-10 µM), levocetirizine (1-10 µM), and desloratadine (10 µM) inhibited PAF-induced histamine release. Rupatadine at 10 µM had an inhibitory effect on hLMC degranulation, but levocetirizine and desloratadine did not. CONCLUSIONS: This study shows that rupatadine and, to a lesser extent, levocetirizine, but not desloratadine, inhibit PAF-induced degranulation in both LAD2 and hLMCs. These findings support the dual antihistamine and anti-PAF effect of rupatadine in allergic disorders.

Asthma outcomes improve with continuous positive airway pressure for obstructive sleep apnea.

BACKGROUND: Continuous positive airway pressure (CPAP) in asthma patients with concomitant obstructive sleep apnea syndrome (OSAS) seems to have a favorable impact on asthma, but data are inconsistent due to methodological limitations of previous studies. METHODS: Prospective, multicenter study. We examined asthma outcomes after 6 months of CPAP in 99 adult asthma patients (mean age 57 years) with OSAS (respiratory disturbance index ≥20). Asthma control and quality of life were assessed with the Asthma Control Questionnaire (ACQ) and the Mini Asthma Quality of Life Questionnaire (MiniAQLQ), respectively. Data were analyzed by intention-to-treat basis. RESULTS: The mean ± SD score of the ACQ decreased from 1.39 ± 0.91 at baseline to 1.0 ± 0.78 at 6 months (P = 0.003), the percentage of patients with uncontrolled asthma from 41.4% to 17.2% (P = 0.006), and the percentage of patients with asthma attacks in the 6 months before and after treatment from 35.4% to 17.2% (P = 0.015). The score of the mAQLQ increased from 5.12 ± 1.38 to 5.63 ± 1.17 (P = 0.009). There were also significant improvements in symptoms of gastroesophageal reflux and rhinitis, bronchial reversibility, and exhaled nitric oxide values (all P < 0.05). No significant changes were observed in drug therapy for asthma or their comorbidities nor in the patients' weight. CONCLUSIONS: Asthma control (both actual and future risk), quality of life, and lung function improved after starting continuous positive airway pressure in asthmatics with moderate to severe obstructive sleep apnea syndrome.

Effects of Rupatadine on platelet-activating factor-induced human mast cell degranulation compared with desloratadine and levocetirizine (The MASPAF study)

Background: Platelet-activating factor (PAF) is a lipid mediator involved in the pathophysiology of several allergic diseases, for example, in the amplification of mast cell (MC) activation in anaphylaxis. Rupatadine is an antihistamine with a demonstrated anti-PAF effect, although its capacity to inhibit PAF-induced MC degranulation has not been fully evaluated. Objectives: To compare the ability of rupatadine to inhibit PAF-induced MC degranulation with that of desloratadine and levocetirizine and to confirm the dual anti-H1 and anti-PAF activity of rupatadine. Methods: The human MC line LAD2 and primary MCs (human lung tissue MCs [hLMCs]) were used. MC mediator release was evaluated using the b-hexosaminidase and histamine release assay. The effects of rupatadine (H1 antagonist + PAF receptor antagonist), desloratadine, and levocetirizine (H1 antagonists) on LAD2 and hLMCs were compared. The PAF receptor antagonists WEB2086, BN52021, and CV6209 were also tested. PAF receptor protein expression was evaluated in both LAD2 and hLMCs. Results: CV6209 and rupatadine inhibited PAF-induced MC degranulation in both LAD2 and hLMCs. In LAD2, rupatadine (5 and 10 μM) and levocetirizine (5 μM), but not desloratadine, inhibited PAF-induced b-hexosaminidase release. Rupatadine (1-10 μM), levocetirizine (1-10 μM), and desloratadine (10 μM) inhibited PAF-induced histamine release. Rupatadine at 10 μM had an inhibitory effect on hLMC degranulation, but levocetirizine and desloratadine did not. Conclusions: This study shows that rupatadine and, to a lesser extent, levocetirizine, but not desloratadine, inhibit PAF-induced degranulation in both LAD2 and hLMCs. These findings support the dual antihistamine and anti-PAF effect of rupatadine in allergic disorders (AU)

Introducción: El factor de activación plaquetario (PAF) es un mediador lipídico que ha sido involucrado en la fisiopatología de diversas enfermedades alérgica, como la amplificación de la activación de los mastocitos (MC) en la anafilaxia. Rupatadina es un antihistamínico que ha demostrado también un efecto anti-PAF, pero no ha sido elucidada su capacidad para inhibir la degranulación mastocitaria inducida por PAF. Objetivo: Evaluar la capacidad de rupatadina para inhibir la degranulación de los MC inducida por PAF en comparación con desloratadina y levocetirizina, con el objetivo de confirmar el efecto dual anti-H1 y anti-PAF de rupatadina. Métodos: Para este estudio se utilizaron la línea celular de mastocitos humanos LAD2 y mastocitos primarios (mastocitos pulmonares (MP)). Los mediadores mastocitarios se midieron utilizando las pruebas de liberación de b-hexosaminidasa e histamina. Los efectos de rupatadina (antagonista H1 + antagonista del receptor del PAF), desloratadina y levocetirizina (antagonista H1) se compararon en LAD2 y MP. También se probaron los antagonistas selectivos del receptor del PAF WEB2086, BN52021, y CV6209. La expresión proteica del receptor del PAF fue evaluada tanto en LAD2 como en MP. Resultados: La expresión del receptor del PAF fue confirmada en LAD2 y MP. De los inhibidores anti-PAF, CV6209 y rupatadina inhibieron la degranulación mastocitaria inducida por PAF, tanto en LAD2 como en MP. En LAD2, rupatadina (5 y 10 μM) y levocetirizina (5 μM), pero no desloratadina, inhibieron la liberación de b-hexosaminidasa inducida por PAF. Rupatadina (1 -10 μM), levocetirizina (1-10 μM), y desloratadina (10 μM) inhibieron la liberación de histamina inducida por PAF. Rupatadina a 10 μM, pero ni levocetirizina ni desloratadina, demostraron efecto inhibitorio alguno sobre la degranulación inducida en MP. Conclusiones: Este estudio demuestra que rupatadina, y en menor medida levocetirizina, pero no desloratadina, es capaz de inhibir la degranulación inducida por PAF en LAD2 y mastocitos pulmonares. Estos hallazgos apoyan el efecto dual anti-H1 y anti-PAF de rupatadina para su uso en las enfermedades alérgicas (AU)

Mechanisms of Anaphylaxis Beyond IgE.

Anaphylaxis is an acute, life-threatening, multisystem syndrome resulting from the sudden release of mediators derived from mast cells and basophils. Food allergens are the main triggers of anaphylaxis, accounting for 33%-56% of all cases and up to 81% of cases of anaphylaxis in children. Human anaphylaxis is generally thought to be mediated by IgE, with mast cells and basophils as key players, although alternative mechanisms have been proposed. Neutrophils and macrophages have also been implicated in anaphylactic reactions, as have IgG-dependent, complement, and contact system activation. Not all allergic reactions are anaphylactic, and the presence of the so-called accompanying factors (cofactors or augmenting factors) may explain why some conditions lead to anaphylaxis, while in other cases the allergen elicits a milder reaction or is even tolerated. In the presence of these factors, allergic reactions may be induced at lower doses of allergen or become more severe. Cofactors are reported to be relevant in up to 30% of anaphylactic episodes. Nonsteroidal anti-inflammatory drugs and exercise are the best-documented cofactors, although estrogens, angiotensin-converting enzyme inhibitors, ß-blockers, lipid-lowering drugs, and alcohol have also been involved. The mechanisms underlying anaphylaxis are complex and involve several interrelated pathways. Some of these pathways may be key to the development of anaphylaxis, while others may only modulate the severity of the reaction. An understanding of predisposing and augmenting factors could lead to the development of new prophylactic and therapeutic approaches.

Nonsteroidal anti-inflammatory drugs enhance IgE-mediated activation of human basophils in patients with food anaphylaxis dependent on and independent of nonsteroidal anti-inflammatory drugs.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) act as cofactors worsening the allergic reactions induced by food allergens. AIM: The aim of this study was to evaluate the effect of both lysine acetylsalicylate (L-ASA) (non-selective cyclooxygenase (COX) inhibitor) and valdecoxib (selective COX-2 inhibitor) in basophils activated by peach lipid transfer protein (Pru p 3) in patients with food-dependent NSAID-induced anaphylaxis (FDNIA). METHODS: Twenty Pru p 3-allergic patients with FDNIA group, eleven peach anaphylaxis not exacerbated by NSAIDs (no-NSAID group) and 5 healthy volunteers were recruited. Basophil activation (BA) was measured as expression of CD63 (Flow(2) CAST(™) ; Bühlmann(®) ), after stimulation with Pru p 3, both alone and in combination with L-ASA (1.13, 3.38 and 6.78 mm) or valdecoxib (0.87, 7.8 and 31.25 µm). RESULTS: Basophils from no-NSAID group were significantly more reactive and sensitive to Pru p 3 than those from the FDNIA group. In both groups, an increase in BA was observed when basophils were exposed to Pru p 3 and L-ASA. In the FDNIA group, valdecoxib partially terminates the BA induced by Pru p 3, whereas in the no-NSAID group, a dual effect was observed depending on the concentration tested. CONCLUSIONS: This study indicates that subjects with food-induced anaphylaxis differ from FDNIA subjects in the higher reactivity and sensitivity of their basophils to allergen challenge. We have shown a direct effect of NSAIDs on basophils using a human model of FDNIA. Our results also suggest that selective COX2 inhibitors might be a safe alternative. BA test may be a useful tool in the study of the pathogenic mechanism of the cofactor phenomenon.

Altered expression and signalling of EP2 receptor in nasal polyps of AERD patients: role in inflammation and remodelling.

BACKGROUND: Down-regulation of the E-prostanoid (EP)2 receptor has been reported in aspirin exacerbated respiratory disease (AERD). We aimed to evaluate the expression and activation of EP receptors in AERD and their role in prostaglandin (PG) E2 signalling. METHODS: Samples were obtained from nasal mucosa of control subjects (NM-C, n=7) and from nasal polyps of AERD patients (NP-AERD, n=7). Expression of EP1-4 was assessed at baseline. Fibroblasts were stimulated with receptor agonists to measure cAMP levels, cell proliferation and granulocyte-macrophage colony-stimulating factor (GM-CSF) release. RESULTS: NM-C and NP-AERD samples and fibroblasts expressed EP2, EP3 and EP4 at baseline. Lower expression of EP2 and higher expression of EP4 was observed in NP-AERD compared with NM-C. Stimulation with PGE2 and butaprost caused a higher increase in cAMP in NM-C than in NP-AERD. On the contrary, CAY10598 produced a higher production of cAMP in NP-AERD compared with NM-C. The anti-proliferative effect of PGE2 and butaprost was lower in NP-AERD than in NM-C fibroblasts. Similarly, the capacity of PGE2 and butaprost to inhibit GM-CSF release was lower in NP-AERD than in NM-C. CONCLUSIONS: The altered expression of EP2 in AERD may contribute to reduce the capacity of PGE2 to mediate anti-proliferative and anti-inflammatory effects.

Mechanisms of anaphylaxis beyond IgE

Anaphylaxis is an acute, life-threatening, multisystem syndrome resulting from the sudden release of mediators derived from mast cells and basophils. Food allergens are the main triggers of anaphylaxis, accounting for 33%-56% of all cases and up to 81% of cases of anaphylaxis in children. Human anaphylaxis is generally thought to be mediated by IgE, with mast cells and basophils as key players, although alternative mechanisms have been proposed. Neutrophils and macrophages have also been implicated in anaphylactic reactions, as have IgG-dependent, complement, and contact system activation. Not all allergic reactions are anaphylactic, and the presence of the so-called accompanying factors (cofactors or augmenting factors) may explain why some conditions lead to anaphylaxis, while in other cases the allergen elicits a milder reaction or is even tolerated. In the presence of these factors, allergic reactions may be induced at lower doses of allergen or become more severe. Cofactors are reported to be relevant in up to 30% of anaphylactic episodes. Nonsteroidal anti-inflammatory drugs and exercise are the best-documented cofactors, although estrogens, angiotensin-converting enzyme inhibitors, β-blockers, lipid-lowering drugs, and alcohol have also been involved. The mechanisms underlying anaphylaxis are complex and involve several interrelated pathways. Some of these pathways may be key to the development of anaphylaxis, while others may only modulate the severity of the reaction. An understanding of predisposing and augmenting factors could lead to the development of new prophylactic and therapeutic approaches (AU)

La anafilaxia se describe como una reacción aguda, con afectación multisistémica que puede causar la muerte del individuo que la padece, y que es consecuencia de una liberación súbita de mediadores originados en mastocitos y basófilos. Los alérgenos alimentarios son los desencadenantes más frecuentemente relacionados con las reacciones anafilácticas, suponiendo entre un 33 y un 56% de todos los casos y hasta un 81% de las anafilaxias en niños. Se considera que las anafilaxias en humanos están mediadas a través de la IgE, y los mastocitos y basófilos juegan un papel principal. Sin embargo, se han descrito otros mecanismos alternativos. De este modo, otros tipos celulares se han implicado en las reacciones anafilácticas, como es el caso de los neutrófilos o los macrófagos. La activación del complemento o del sistema de contacto, así como mecanismos mediados a través de la IgG, también han sido descritos. No todas las reacciones alérgicas acaban siendo una anafilaxia, de modo que se ha postulado la existencia de factores acompañantes (cofactores o factores potenciadores) que explicarían porque en algunos casos los alérgenos no son capaces de inducir una reacción alérgica o inducen una reacción leve, mientras que en otros casos desencadenan reacciones graves. Los cofactores se consideran relevantes hasta en el 30% de los episodios anafilácticos. En presencia de esos cofactores, las reacciones alérgicas pueden desarrollarse con concentraciones inferiores de alérgeno o ser más grave que en ausencia de ellos. Los antinflamatorios no esteroideos (AINE) y el ejercicio físico son los cofactores mejor conocidos, aunque se han descrito muchos otros, como los estrógenos, los inhibidores del enzima convertidor de la angiotensina, los β-bloqueantes, los hipolipemiantes o el alcohol. Los mecanismos subyacentes en la anafilaxia son muy complejos y múltiples mecanismos parecen estar interrelacionados. Algunos de ellos pueden ser claves en el desarrollo de la anafilaxia, mientras que otros estarían únicamente modulando la gravedad de la reacción. La compresión de estos mecanismos es clave y permitirá el desarrollo de nuevas estrategias profilácticas y terapéuticas en la anafilaxia (AU)