Delta strain COVID19 causes clinical symptoms of
Case 247
【Discussion】
World Health Organization (WHO) nominated four corona virus vaiants causing COVID-19: α, β, γ and δ. Variant-α corona virus caused pandemic in England, variant-β corona virus did in South Africa, variant-γ corona virus did in Brazil and variant- δ corona virus did in India. At present on August 7th 2021, variant- δ corona virus prevailed worldwide including Japan. Delta (δ) corona virus is reported to adhere to epithelial cells of bronchial trees and alveolar cells more than other corona viruses, inducing to cause the illness onset to the young population more. While fever and cough remain, delta strains cause sore throat and running nose more rather than loss of small and/or taste on the previous strains (1-3).
The numbers of COVID-19 patients not only with mild and moderate degree but also with severe degree are increasing. However, the number of new deaths is not so high as the previous pandemic probably because aged population already got the service of vaccination before pandemic with variant- δ corona virus.
Chest CT findings of COVID-19 trace the process of radio-opacity from faint ground glass, dense ground glass, reticular or melon skin ground glass finally to consolidation. The definition of ground glass is that vessels can be identified in the opacity, while that of consolidation is that vessels cannot because the opacity density elevates until equivalent to vessel opacity. Faint or dens opacity is corresponded to surfactant secretion, dens opacity or melon skin opacity is corresponded to IgA and Ig G production and infiltration of lymphocytes and macrophages, and consolidation is corresponded to edematous fluid via permeability of vessels by neutrophils infiltration. Steroid works to improve the symptom of dyspnea because it blocks the infiltration of neutrophils, leading to interrupt the permeability of vessels. In our case, we confirmed this process from faint glass to consolidation via reticular or melon glass ground glass (Figs 1-5).
As risk factors for COVID-19, lymphopenia, elevation of D-dimer, Kl-6, LDH, high age, diabetes mellitus are listed (4, 5). Lymphopenia due to damage by corona virus infectiom indicates weakness of immune system because lymphocytes are responsible to immune command and antibody production. Elevation of D dimer indicates thrombus formation following extracellular trap by macrophages and neutrophils. Elevation of Kl-6 indicates the damages of type II alveolar cells. Elevation of LDH indicates damage of living cells of the body. It might be due to damages of alveolar cells in case of COVID 19. High age and diabetes mellitus (DM) are reported to be the risk factors for falling in COVID-19. Although its mechanism is yet to be clarified, high age and DM are risk factors for all inflammatory diseases, including influenza.
In our case, although he was young in thirties, he had diabetes mellitus as a risk factor, lymphocytes decreased until 705/mm3, Kl-6 increased to 147 U/mL. Subsequently, his symptoms got improving, leading to discharge and return to social life.
【Summary】
We presented a thirty nine year-old male with COVID-19 by variant- δ corona virus. He suffered from diabetes mellitus. It is borne in mind that α, β, γ and δ corona virus caused pandemic in England, South Asia, Brazil and India, respectively. CT findings of corona pneumonia demonstrate a process of faint ground glass, thick ground glass, melon skin ground glass and consolidation. Delta (δ) corona virus is reported to adhere to epithelial cells of bronchial trees and alveolar cells more than other variant corona viruses, inducing to cause the illness onset to the young population more. Faint or dens opacity is corresponded to surfactant secretion, dens opacity or melon skin opacity is corresponded to IgA and Ig G production and infiltration of lymphocytes and macrophages, and consolidation is corresponded to edematous fluid via permeability of vessels by neutrophils infiltration. Risk factors of causing the onset of COVID-19 are lymphopenia, elevation of D-dimer, Kl-6, LDH, high age and diabetes mellitus are listed.
【References】
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2.Here's How the Delta Variant Symptoms Differ From the Initial COVID Strain.2021/07/27
3.The symptoms of the Delta variant appear to differ from ... 2021/08/08
4.Deng K, et al. Prognostic roles of KL-6 in disease severity and lung injury in COVID-19 patients: A longitudinal retrospective analysis. J Med Virol. 2021;93:2505-2512.
5.Frix AN, et al. Could KL-6 levels in COVID-19 help to predict lung disease? Respir Res. 2020;21:309. doi: 10.1186/s12931-020-01560-4.
2021.10.21