RESUMEN
Mucosal immunity plays a crucial role in controlling upper respiratory infections, including influenza. We established a quantitative ELISA to measure the amount of influenza virus-specific salivery IgA (sIgA) and salivary IgG (sIgG) antibodies using a standard antibody broadly reactive to the influenza A virus. We then analyzed saliva and serum samples from seven individuals infected with the A(H1N1)pdm09 influenza virus during the 2019-2020 flu seasons. We detected an early (6-10 days post-infection) increase of sIgA in five of the seven samples and a later (3-5 weeks) increase of sIgG in six of the seven saliva samples. Although the conventional parenteral influenza vaccine did not induce IgA production in saliva, vaccinated individuals with a history of influenza infection had higher basal levels of sIgA than those without a history. Interestingly, we observed sIgA and sIgG in an asymptomatic individual who had close contact with two influenza cases. Both early mucosal sIgA secretion and late systemically induced sIgG in the mucosal surface may protect against virus infection. Despite the small sample size, our results indicate that the saliva test system can be useful for analyzing upper mucosal immunity in influenza.
Asunto(s)
Inmunidad Mucosa/fisiología , Gripe Humana/inmunología , Saliva/inmunología , Adulto , Anciano , Anticuerpos Antivirales/análisis , Anticuerpos Antivirales/metabolismo , Formación de Anticuerpos , Estudios de Cohortes , Femenino , Historia del Siglo XXI , Humanos , Inmunoglobulina A/análisis , Inmunoglobulina A/metabolismo , Inmunoglobulina A Secretora/análisis , Inmunoglobulina A Secretora/metabolismo , Inmunoglobulina G/análisis , Inmunoglobulina G/metabolismo , Subtipo H1N1 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza/uso terapéutico , Gripe Humana/diagnóstico , Gripe Humana/prevención & control , Japón , Estudios Longitudinales , Masculino , Valor Predictivo de las Pruebas , Pronóstico , Saliva/química , Saliva/metabolismo , Adulto JovenRESUMEN
INTRODUCTION: This review discusses how nasal congestion may have benefits as a mechanism of defence against respiratory viruses. METHODS: A literature research was conducted on respiratory viruses and nasal congestion, following a recently published review on how temperature sensitivity is important for the success of common respiratory viruses. RESULTS: The literature reported that common respiratory viruses are temperature sensitive and replicate well at the cooler temperatures of the upper airways (32°C), but replication is restricted at body temperature (37°C). The amplitude of the phases of congestion and decongestion associated with the nasal cycle was increased on infection with respiratory viruses and this caused unilateral nasal congestion and obstruction. Nasal congestion and obstruction increase nasal mucosal temperature towards 37°C and therefore restricted the replication of respiratory viruses. CONCLUSION: Nasal congestion associated with the nasal cycle may act as a mechanism of respiratory defence against infection with respiratory viruses.