DYNAMICS OF CLINICAL SYMPTOMS AND SECRETORY IMMUNOGLOBULIN A IN COVID-19 CONVALESCENT PATIENTS

ABSTRACT

The post-COVID-19 recovery period is characterized by persistence of some symptoms, with immunological alterations being of great importance. Development of preventive measures to normalize mucosal immunity after a coronavirus infection determines the relevance of the current study. The aim was to study dynamics of clinical symptoms and level of secretory immunoglobulin A in individuals after a novel coronavirus infection as well as evaluate effectiveness of using IFNα-2b. Materials and methods. A study was conducted with patients aged 18 to 60 years old (n = 130), surveyed 1 to 9 months after post-infection, as well as in apparently healthy individuals lacking COVID-19 (n = 15). Previous novel coronavirus infection and post-COVID manifestations were verified based on medical documentation, complaints, anamnesis data, physical examination and questionnaires. The concentration of salivatory and nasopharyngeal mucosal sIgA was measured dynamically prior to and after administration of local therapy with IFNα-2b (gel applied intranasally twice a day for 30 days). Results. The acute period of COVID-19 was characterized by fever, anosmia, severe asthenia (fatigue and weakness), muscle and joint pain. Among the post-COVID manifestations at early period (1–3 months), pain in the joints and muscles (75.0%) as well as elevated body temperature (21.2%) were reliably detected, whereas in the long period (6–9 months) there were revealed dominance with the same frequency of shortness of breath, muscle and joint pain (75.8%, respectively). Based on examination data in healthy subjects, there was determined an arbitrary normal range of secretory IgA in saliva — 6.45±1.81 mg/ml and nasal swabs — 13.43±3.24 mg/ml. In the group of patients 1–3 months post-infection, therapy with IFNα-2b one month later resulted in significantly increased level of secretory IgA in saliva (from 1.84±0.28 to 5.78±1.96 mg/ml) and in nasal swabs (from 28.61±3.0 to 39.83±3.85 mg/ml) by more than 3- and 1.5-fold, respectively. In the group of patients without therapy was featured with stably sustained decline in sIgA level up to 9 months after COVID-19. In particular, the level of saliva sIgA ranged from 2.36±0.56 down to 2.16±0.66 mg/ml, and in nasal smears — from 15.66±1.32 to 10.23±1.07 mg/ml that differed insignificantly compared to baseline level. The rate of respiratory diseases prevailed in this group (27.6% of cases), which fully lacked in the group of topically administered IFNα-2b. Conclusion. In the post-COVID period, multiple organ disorders persist and reduced sIgA level is registered. Intranasally applied IFNα-2b made possible to normalize sIgA level and prevent accumulation of respiratory infectious pathologies.