RESUMEN
BACKGROUND: Exacerbation frequency strongly influences treatment choices in patients with severe asthma. RESEARCH QUESTION: What is the extent of the variability of exacerbations rate across countries and its implications in disease management? STUDY DESIGN AND METHODS: We retrieved data from the International Severe Asthma Registry, an international observational cohort of patients with a clinical diagnosis of severe asthma. We identified patients ≥ 18 years of age who did not initiate any biologics prior to baseline visit. A severe exacerbation was defined as the use of oral corticosteroids for ≥ 3 days or asthma-related hospitalization/ED visit. A series of negative binomial models were applied to estimate country-specific severe exacerbation rates during 365 days of follow-up, starting from a naïve model with country as the only variable to an adjusted model with country as a random-effect term and patient and disease characteristics as independent variables. RESULTS: The final sample included 7,510 patients from 17 countries (56% from the United States), contributing to 1,939 severe exacerbations (0.27/person-year). There was large between-country variation in observed severe exacerbation rate (minimum, 0.04 [Argentina]; maximum, 0.88 [Saudi Arabia]; interquartile range, 0.13-0.54), which remained substantial after adjusting for patient characteristics and sampling variability (interquartile range, 0.16-0.39). INTERPRETATION: Individuals with similar patient characteristics but coming from different jurisdictions have varied severe exacerbation risks, even after controlling for patient and disease characteristics. This suggests unknown patient factors or system-level variations at play. Disease management guidelines should recognize such between-country variability. Risk prediction models that are calibrated for each jurisdiction will be needed to optimize treatment strategies.
RESUMEN
The COVID-19 pandemic has collapsed the health systems of many countries in the world and comorbidities in adults have exponentially increased their mortality; in matters of asthma, it has not been possible to establish a defining relationship in mortality. The clinical manifestations of asthmatic patients with SARS COV 2 are presented in a wide range; from asymptomatic to those who experience acute respiratory failure. The most sensitive method for the diagnosis of SARS-CoV-2 infection is RT-PCR. Antigen and serologic tests are quicker than RT-PCR, but they are less sensitive. Radiologic studies and the computed tomography of the chest assist in the diagnosis and follow-up of SARS-CoV-2 infection. The use of spirometry for diagnosis and follow-up is restricted due to the elevated risk of contagion. It has been shown that eosinophilia and TH2 inflammation, due to their antiviral immune effect, are protective factors against severe SARS-CoV-2/COVID-19. Patients with mild asthma express less angiotensin converting enzyme receptors (ACE2), and those with neutrophilic asthma express it in greater proportion, which suggests more severe presentations of COVID-19. The conventional asthma treatment modulates the SARS-CoV-2/COVID-19 immune response, which is why patients with controlled asthma have non-severe manifestations of COVID 19, however, the mechanisms are not clear.
La pandemia de COVID-19 ha colapsado los sistemas de salud de muchos países del mundo y las comorbilidades en adultos han incrementado exponencialmente su mortalidad; respecto al asma, no se ha podido establecer una relación determinante en la mortalidad. Las manifestaciones clínicas del paciente con asma y SARS-CoV-2 se presentan con una amplia gama, desde asintomáticas hasta las que experimentan insuficiencia respiratoria aguda. El método más sensible para el diagnóstico de la infección por SARS-CoV-2 es la RT-PCR. Las pruebas de antígeno y serológicas son más rápidas que la RT-PCR, pero menos sensibles. Los estudios radiológicos y la tomografía computarizada de tórax auxilian en el diagnóstico y seguimiento de la infección por SARS-CoV-2. El uso de la espirometría se restringe para el diagnóstico y seguimiento debido al alto riesgo de contagio. Se ha demostrado que la eosinofilia y la inflamación TH2, debido a su efecto inmunológico antivírico, son factores protectores contra SARS-CoV-2/COVID-19 severo. Los pacientes con asma leve expresan menos receptores de la enzima convertidora de angiotensina (ECA2) y aquellos con asma neutrofílica expresan mayor proporción, lo que sugiere presentaciones más severas de COVID-19. El tratamiento convencional del asma modula la respuesta inmunitaria del SARS-CoV-2/COVID-19, por lo cual, los pacientes con asma controlados tienen manifestaciones no graves de COVID-19, aunque los mecanismos no están claros.
