The COVID-19 is a multifactorial illness as genetic and environmental factors may contribute to incidence rates observed in various nations and ethnic groups. Age and comorbid disorders like diabetes, hypertension, and liver and kidney ailments are examples of non-genetic variables [8].Acute respiratory distress syndrome (ARDS) is the most severe COVID-19 symptoms [9].The global percentage of the population infected with COVID-19 grew because of combined impact of these variables. One of strength of this study is that it is considered the first publication included A1AT gene polymorphism among infected Saudi COVID-19 patients.
This cross-sectional study showed that 24% of cases were associated with other diseases. About half of them were classified severe cases. A1AT gene polymorphism was examined in this study. This is only one example of a hereditary disorder that could make individuals more prone to COVID-19. A hereditary illness referred to as A1ATD causes liver and/or lung damage. The symptoms of A1ATD are often misinterpreted due to their overlapping with pulmonary and hepatic disorders. This has led to a significant underdiagnosis of A1ATD globally. The symptoms of A1ATD-related lung ailments are like those of other obstructive lung conditions, and patients are often misdiagnosed for years [10]. Comorbid conditions linked to A1ATD, such as diabetes, hypertension, COPD, and chronic renal disease, are also independently linked to a higher incidence of COVID-19 [8].
Several studies hypothesized that severe impact of COVID-19 is influenced by areas of high prevalence of A1ATD [3].A1AT has been revealed to block this protease, which might hinder SARS-CoV-2 cell entry and thus minimize viral replication[6].Additionally, the study demonstrated that sera from participants with an A1AT-deficient genotype have a decreased capacity to prevent the entry of Wuhan-Hu-1 (WT) and B.1.617.2 (Delta), but not B.1.1.529 (Omicron). The results illustrated potential involvement of these serum parameters in controlling viral entry in vivo[11].
Table 2C suggested that SS and ZZ genotypes may be tied with an increased risk of severe COVID-19 infection, while the MM genotype may be protective against severe COVID-19 infection. Furthermore, number of A1ATD individuals among Saudi population is probably not clear or not accurate because some patients with A1ATD -such as children- have not yet been diagnosed with COPD or liver illness linked to A1ATD. These preliminary findings inspired us to move forward with additional plans to ascertain the frequency of A1AT in sizable portion of Saudi population and additionally seek out other genotypes, including VIT-D. Another study that investigated healthy Saudi population, registered frequency of mutant S and Z A1AT alleles (9.49% and 3.19%; respectively) [12].
The PI*ZZ A1AT genotype's global prevalence in patients with COPD was evaluated in a recent study that comprised 48 nations. According to the study, which covered 11 Asian nations, rate of COPD in persons over 40 years is 9%. The greatest PI*ZZ weighted average prevalence among COPD individuals. Saudi Arabia was found among high values [13]. Similarly, another study revealed high prevalence of Z allele has been observed among Saudi Arabia (15:1000) [10]. Further confirmatory investigations conducted among Italians from different locations revealed that the region most impacted by COVID-19, northern Italy, had higher prevalence of the deficient linked phenotypes SZ, MZ, and ZZ than Southern region, with 47% of all cases only documented [14]. It was also reported that, a robust correlation was noticed between the PI*Z variant and the number of COVID-19 cases (r = 0.8584) and deaths (r = 0.8713) in 68 countries [15]. The PI*ZZ, PI*SZ, and PI*MZ rates are projected to be approximately 12% higher for Europeans and Latinos, who also make up the majority ethnic group in the nations with the largest number of COVID-19 cases and deaths [16].
On the other hand, a recent retrospective analysis bizarre in small cohort of hospitalized subjects revealed that only 2 were found to be PI*MZ and none for PI*MS, PI*SZ, PI*SS, or PI*ZZ individuals who are heterozygotes for A1AT alleles are not at high risk of acquiring severe COVID-19 [11]. Furthermore, it can be challenging to distinguish out baffling effect of patients' awareness of their A1ATD status. According to a survey performed in Germany, individuals suffering from A1ATD were 65% less likely to have been infected than the general population, and they were more likely to restrict their social groupings as a result to their greater concern about infection [12]. It was revealed that, there was no increment in either SARS-CoV-2 infection or death rates in presence of S- or Z-A1AT alleles among British patients [16]. Patients with PI*MM and PI*SS alleles, and non-smoking patients with the PI*MZ allele, do not have an abundant risk of lung ailments [10].
People with PI*MM genotype, concomitant with defective S and Z alleles have serum A1AT levels that are reduced by around 40% and 85%; respectively [17]. Because COVID-19 is linked to increased oxidative stress status [18], higher levels of A1AT may become useless. This fact was emphasized in (Table 4) that revealed 6 out of 15 (46.6%) diabetics were carrying MM A1ATgenotype, but they were positively associated with low levels of circulated A1AT, and this can be due to uncontrolled glucose levels. VIT-D deficiency level may link with type 2 diabetics to A1ATD which may cause a higher frequency COVID-19. We could explain the non-significance of certain genotypes due to small numbers and nearly similar levels of the parameters. Interestingly that all our COVID-19 patients have VIT-D deficiency.
In addition, A1AT homeostasis in diabetic nephropathy leads to reduced levels of A1AT [19]. The non-enzymatic glycosylation of A1AT or oxidation of methionine in A1AT active site, may be the trigger for the decline in serum trypsin inhibitory capacity [20]. It was revealed that, VIT-D active form drives CD4+ T cells to emit A1AT, via direct contact with complement C3a, strengthens IL-10 secretion; implying that A1AT is crucial for active VIT-D to induce IL-10. linked with inflammation status and autoimmunity [21]. It was evident that there is a probable link between VIT-D levels and COVID-19 severity and lethality [22]. Our study revealed strong association with VIT-D, as there was high significant between asymptomatic and severe patients (Tables 2B,2C,3B). VIT-D has robust safeguard against acute lung injury and ARDS via regulating RAS and limiting bradykinin buildup. On other hand, COVID-19 patients utilize cytokine storm and bradykinin storm to counterfeit the virus. In agreement with our results, is well-known that COVID-19 patients have substantial declines in VIT-D levels [23].
In our study, severe patients exhibited a greater elevation in circulating IL-6 levels than asymptomatic or moderate patients, despite the latter group experiencing a reduction in A1AT levels. Hyper-inflammation and coagulopathy are hallmarks of COVID-19, and in more severe instances, an intensifying "cytokine storm" may trigger respiratory failure, sepsis, and even death [23]. Extrapolated the severity of COVID-19 patients is linked to a rise in the IL-6/A1AT ratio, which suggests an inadequate response of A1AT to IL-6 production. The IL-6/A1AT ratio in severe COVID-19 patients (mean 1.4) was significantly higher compared to asymptomatic or moderate patients (0.16, 0.21, respectively, P=0.001). This extensively elucidated that severe patients have a decreased A1AT response to inflammation (Table 2B,2C).
It was postulated that, innate immune defense relies heavily on A1AT, whose plasma concentration may spike 2-4 times during the acute phase protein response. Protease-antiprotease disparities may emerge during the COVID-19 clinical course of the virus [24]. It was clearly reported that, patients in the intensive care unit (ICU) demonstrated a higher IL-6/A1AT ratio. Furthermore, clinical improvement was observed in ICU patients whose IL-6/A1AT ratio declined during treatment; no improvement was noted in patients whose ratio remained larger [25]. Another study emphasized that primary cytokine storm tracked in COVID-19 individuals exhibiting mild to severe symptoms is serum IL-6 [26]. A1AT can alter actions resulting in descending IL-6 inhibition, which has a crucial role in COVID-19 pathogenicity [27]. Within a multi-center investigation involving more than two thousand COVID-19 patients, the Pi*Z allele and/or a plasma A1AT level less than 116 mg/dl were significantly linked to severe COVID-19 as opposed to non-severe cases [26]. We could have concluded from table (8 A, B) that IL-6 and ATT can be used as predictor for severity of COVID-19; While VIT-D was a fuzzy (ambiguous) risk factor for COVID-19 especially overall patients have VIT-D deficiency.
Results from another study showed that, in comparison to Italian population, patients with A1ATD had a considerably increased relative risk (8.8; P=0.0001) of symptomatic severe SARS-COV-2. 209 persons with significantly lower serum A1AT levels and A1AT-deficient genotypes participated in the survey [28]. Furthermore, in our severe COVID-19 patients, the NLR was found to be higher compared to those with asymptomatic or mild cases, with mean NLRs of 10, 2.5, and 7.11; respectively (Table 2 and 3). Severe COVID-19 progression is predicted by incremented absolute neutrophil count, elevated neutrophil percentage, and high blood neutrophil: lymphocyte ratio [29]. One of the postulates of the mechanisms by which A1AT can alleviate COVID-19 is the creation of neutrophil extracellular traps (NETs), a complex extracellular structure made of neutrophil-derived DNA, histones, and proteases that is linked to the immune-thrombosis of COVID-19, can be resisted by A1AT suppression of elastase [8]. Notably, dysregulated neutrophil elastase activity has been linked to diminished plasma concentrations or A1AT function, which might occur in pulmonary emphysema [30]. It was declared that significant higher severity and mortality were linked to NLR ratios of ≥4.5 and ≥6.5; respectively [2]. In addition, under hypoxic conditions, ZZ-A1ATD neutrophils produce more ROS than MM control subjects [30].