ABSTRACT
BACKGROUND: The Middle East respiratory syndrome coronavirus (MERS-CoV) is a highly pathogenic zoonotic betacoronaviruses and a global public health concern. Better undersetting of the immune responses to MERS-CoV is needed to characterize the correlates of protection and durability of the immunity and to aid in developing preventative and therapeutic interventions. While MERS-CoV-specific circulating antibodies could persist for several years post-recovery, their waning raises concerns about their durability and role in protection. Nonetheless, memory B and T cells could provide long-lasting protective immunity despite the serum antibodies levels. METHODS: Serological and flow cytometric analysis of MERS-CoV-specific immune responses were performed on samples collected from a cohort of recovered individuals who required intensive care unit (ICU) admission as well as hospital or home isolation several years after infection to characterize the longevity and quality of humoral and cellular immune responses. RESULTS: Our data showed that MERS-CoV infection could elicit robust long-lasting virus-specific binding and neutralizing antibodies as well as T and B cell responses up to 6.9 years post-infection regardless of disease severity or need for ICU admission. Apart from the persistent high antibody titers, this response was characterized by B cell subsets with antibody-independent functions as demonstrated by their ability to produce TNF-α, IL-6, and IFN-γ cytokines in response to antigen stimulation. Furthermore, virus-specific activation of memory CD8+ and CD4+ T cell subsets from MERS-recovered patients resulted in secretion of high levels of TNF-α, IL-17 and IFN-γ. CONCLUSIONS: MERS-CoV infection could elicit robust long-lasting virus-specific humoral and cellular responses.
ABSTRACT
BACKGROUND: Although COVID-19 is an acute disease that usually resolves rapidly in most cases, the disease can be fatal and has a mortality rate of about 1% to 56%. Alveolar injury and respiratory failure are the main causes of death in patients with COVID 19. In addition, the effect of the disease on other organs is not fully understood. Renal system affection has been reported in patients with COVID 19 and is associated with a higher rate of diverse outcomes, including mortality. Therefore, in the present work, we reported the clinical characteristics and laboratory data of hospitalized patients with COVID-19 and analyzed the manifestations that indicated renal system involvement and their impact on clinical outcomes. MATERIALS AND METHODS: This was an observational retrospective study conducted at King Fahd Specialist Hospital, Buraydah, Saudi Arabia. All patients with COVID-19 who were admitted to this Hospital from April to December 2020 were included in the study. The patients' findings at presentation were recorded. Demographic data and laboratory results (hematuria, proteinuria, urinary sediment cast and pus cell presence, and kidney function tests) were retrieved from electronic patient records. RESULTS: One hundred and ninety-three patients with confirmed COVID 19 were included in the study. Dipstick examinations of all urine samples showed proteinuria and hematuria in 53.9% and 22.3% of patients, respectively, whereas microscopic examination revealed the presence of pus and brown muddy granular casts in 33.7% and 12.4% of samples, respectively. Acute kidney injury was reported in 23.3% of patients. A multivariable analysis demonstrated that hematuria was associated with acute kidney injury (AKI) (OR, 2.4; 95% CI, 1.2-4.9; P = 0.001), ICU admission (OR, 3.789; 95% CI, 1.913-7.505; P = 0.003), and mortality (OR, 8.084; 95% CI, 3.756-17.397; P = 0.002). Conversely, proteinuria was less significantly associated with the risk of AKI (OR, 1.56; 95% CI, 1.91-7.50; P = 0.003), ICU admission (OR, 2.493; 95% CI, 1.25-4.72; P = 0.001), and mortality (OR, 2.764; 95% CI, 1.368-5.121; P = 0.003). Patients with AKI had a higher probability for mortality than did those without AKI (OR, 14.208; 95% CI, 6.434-31.375; P = 0.003). CONCLUSION: The manifestations of the involvement of the renal system are not uncommon in COVID-19. These manifestations included proteinuria, hematuria, and AKI and were usually associated with a poor prognosis, including high incidences of both ICU admission and mortality.