Expression of Concern (20 ^th October 2023): We, the Publisher and Editor of F1000Research, are issuing an Expression of Concern for the following article:

Abd HA, Kasim AA and Shareef LG. Serum levels of α1-antitrypsin, interleukin-1β and interleukin-6 in Iraqi COVID-19 patients: A cross-sectional study [version 1; peer review: awaiting peer review]. F1000Research 2022, 11:921 ( https://doi.org/10.12688/f1000research.124473.1).

After publication of this article, questions about the integrity of the ethical approval and methodology were brought to the attention of the F1000 Editorial Team. We have reached out to the authors requesting that they respond to the concerns raised and provide additional information to support the integrity of the content. However, despite multiple attempts to contact the authors, and their institution, they have not responded to our queries within the requested timeframe. Therefore, as we continue to work through the issues raised, we advise readers to interpret the information presented in the article with due caution. The authors have been sent notification about this Expression of Concern.

Editorial Note (13 ^th July 2023): Since publication, concerns have been raised to the Editorial Team regarding the ethical approval for this study, as well as overlap in the sample and methods to other papers by these authors. The Editorial Team requested explanations regarding the similarities on 19 ^th May and 6 ^th June 2023, and the institution was contacted on 21 ^st March, 6 ^th April and 25 ^th April 2023 to verify the ethical approval. Neither the author nor institution have provided responses to our requests. The Editorial Team will update this Editorial Note as the situation progresses. Peer review activity has been suspended for this article until we receive an explanation from the authors/institution.

A cluster of pneumonia cases with unknown origins emerged in Wuhan, Hubei Province, China, in December 2019. On January 7, 2020, the causal microorganism was identified as a novel coronavirus (CoV) known as 2019-nCoV. ^{1 – 4} The virus was later termed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). ^{5 – 7} The World Health Organization (WHO) termed the illness coronavirus disease 2019 (COVID-19). The illness has spread internationally, and WHO designated it a pandemic on March 11, 2020. ^{8 – 10} COVID-19, like the other coronavirus infections, severe acute respiratory syndrome (SARS) and the Middle East respiratory syndrome (MERS), have been associated with increased cytokine production. The cytokine release syndrome, often known as a “cytokine storm”, has been broadly acknowledged as the principal cause of morbidity in these coronavirus outbreaks. ^{11 , 12} In addition, cytokine storm has been linked to the development of acute respiratory distress syndrome and multiorgan dysfunction syndrome after COVID-19 infection. ¹³ SARS-CoV-2 activates the NLR family pyrin domain containing 3 (NLRP3) inflammasome, resulting in increased synthesis and release of two cytokines, interleukin (IL)-1β and IL-18. ^{14 , 15} In turn, IL-1β stimulates IL-6 production, ¹⁶ while IL-18 stimulates interferon (IFN)-γ production. ¹⁷ Commonly, the IL-1β pathway is more prevalent in COVID-19 patients than the IL-18 pathway. ¹⁸

Moreover, half of those diagnosed with COVID-19 were reported to have high levels of IL-6. ¹⁹ According to a recent meta-analysis, a more significant blood IL-6 level is a predictor of COVID-19 disease severity and patient clinical consequences. ²⁰ Another meta-analysis concluded that increasing the blood IL-6 level, the more severe the COVID-19 condition and that considerably higher serum levels are observed in patients who did not recover than in people who survived. In addition, they appear more frequently in severely and critically sick COVID-19 sufferers than in moderately unwell COVID-19 patients, and they occur more frequently in individuals who died from the condition than in those who live. ²¹ The Food and Drug Administration (FDA) licensed two types of IL-6 inhibitors, anti-IL-6 receptor monoclonal antibodies (mAbs) and anti-IL-6 mAbs, to modify IL-6 levels or effects to minimize the severity of COVID-19 in patients with systemic inflammation. ²² Serum IL-1β concentrations were found to be much higher in COVID-19 patients, and many trials looked at the use of anakinra, an IL-1β receptor blocker, in managing COVID-19 cases of acute severe respiratory distress, with mixed outcomes. ^{23 – 26} Landi et al., showed that giving canakinumab, an anti-IL-1β mAb, to COVID-19 patients with acute severe respiratory failure results in clinical improvement. ²⁷

α1-antitrypsin (AAT) is an acute phase reactant primarily synthesized in the liver and released into circulation serving a range of physiological effects. Monocytes/macrophages, activated neutrophils, and epithelial cells express it less. ²⁸ In addition, several cytokines, including IL-1β, IL-6, tumor necrosis factor (TNF)-α, and bacterial lipopolysaccharide, induce hepatocytic expression. ²⁹ AAT is the prototypical member of the superfamily of serine protease inhibitors (serpins). The primary role of AAT is not to block proteases but to modulate their proteolytic activity, such as encouraging effective host resistance to infections while preserving healthy tissue from proteolytic harm. ³⁰ In addition to protecting against proteolytic injury, AAT has an essential role in reducing acute pulmonary damage by interfering with inflammation, coagulation, and induction of apoptosis. ³¹

Both in chronic obstructive pulmonary disease (COPD) and emphysema, AAT deficiency has been associated with alveolar cell destruction. ³² AAT from healthy human donors may be used to boost alpha-1 levels in the blood and lungs of individuals with AAT deficiency who have been diagnosed with emphysema. ³³ Yang et al., suggested that people with AAT deficiency are more likely to get COVID-19 and also have worse prognosis compared to healthy people and that for COVID-19 patients with AAT deficiency who are receiving augmentation therapy with human plasma purified AAT, a dose more significant than just the standard maintenance dosages must be considered. ³⁴ In addition, several investigations have shown that human AAT has anti-inflammatory and anti-COVID-19 properties. ^{35 – 38}

This research aimed to compare the blood levels of AAT, IL-1β, and IL-6 in COVID-19 patients to those in seemingly healthy people and to look for any possible links between these inflammatory markers.

The participants in this research varied in age from 39–65 years old in the illness group to 37–67 years old in the healthy control group. There was no difference in mean age between the patient and control groups (P=0.215). Regarding sex, 23 (51%) of the 45 patients were men, while 22 (49%) were women. A total of 20 (44%) of the 45 people in the control group were men, whereas 25 (56%) were women. Table 2 ⁴⁴ shows no significant difference (P=0.527) between the sexes of the participants in this research.

According to the results of the study, there was a significant difference in the measured value of AAT between the two groups. The median (IQR) levels of AAT in the patient and control groups were 5.55 (1.86) mg/ml and 4.11 (2.82) mg/ml, respectively, with a P=0.001 ( Figure 1). In terms of IL-1β, this research discovered a substantial difference between the analyzed groups, with the median (IQR) of IL-1β in the COVID-19 patient group being 1,672 (475) pg/L and 923 (178) pg/L in the control group, P=0.001 ( Figure 2). Also, there is a significant difference in the measured levels of IL-6 between the comparison groups, as indicated in Table 3 and Figure 3. IL-6 levels in the COVID-19 patient and control groups were 105.8 (39.24) ng/L and 51.15 (12.76) ng/L, respectively, P=0.001.

Correlation studies between AAT, IL-6, and IL-1β of the participants (n=90) are shown in Table 4. Serum AAT has a significant positive correlation with IL-1β and IL-6. Also, serum IL-6 has a significant positive correlation with IL-1β (P<0.01).

Because of its anti-inflammatory and anti-viral effects, AAT is a crucial protease inhibitor in the pathophysiology of SARS-CoV-2 infection. Similarly to the current study, the findings of a prior study conducted by Ercin et al. (2021), which included 86 participants, 44 patients diagnosed with COVID-19 and 42 as the control group, revealed that patients with COVID-19 infection demonstrated a significant increase in AAT threshold, which is a great predictor for disease termination. ⁴¹ IL-6 is a crucial modulator of the inflammatory and immunological response to infection or trauma. Excessive IL-6 levels are associated with cytokine storm, which may result in multiorgan dysfunction and respiratory failure. Controlling systemic IL-6 levels in SARS-CoV-2 infected individuals is thus critical. The present research found that patients in the COVID-19 group had substantially higher IL-6 levels (P=0.001) than participants in the healthy control group, with a median (IQR) of IL-6 for patients being 105.8 (39.24) ng/L and the healthy control group being 51.15 (12.76) ng/L. Tang et al., (2021) performed a cross-sectional study with 100 COVID-19 patients categorized into three subgroups: common (n=56), severe (n=28), and critical (n=16); the mean ± SD for each group being 23.93 ± 9.64, 69.22 ± 22.98, and 160.34 ± 26.15, respectively, P=0.05, indicating a significant difference between the three groups. ⁴² IL-1β is a cytokine that plays a crucial role in immune system activity. Because high levels are linked to cytokine storm syndrome, keeping IL-1β levels under control following COVID-19 infection is critical. The present research found a substantial increase in IL-1β levels in the COVID-19 patient group compared to the healthy control group, with a median (IQR) of 1,672 (475) pg/L for the patient group and 923 (178) pg/L for the control group (P=0.001). Furthermore, Lu et al., (2021) discovered that the levels of IL-1β, along with other examined biomarkers, were considerably higher in COVID-19 patients compared to healthy subjects. ⁴³ As shown in Table 4, there is a significant positive correlation between IL-1β and IL-6 (P<0.001), this is because IL-1β stimulates IL-6 production. ¹⁶ Also, there is a significant positive correlation between AAT, IL-6, and IL-1β (P<0.001) because the hepatocytic expression of AAT is stimulated by several cytokines, two of them are IL-1β and IL-6. ²⁹

Because high levels of AAT are crucial during COVID-19 infection, the physician may request a serum AAT level test to prescribe AAT supplements if levels are low. It may also be regarded as a favorable prognostic factor throughout the illness phase, and similar results apply if COVID-19 patients do not have AAT deficiency before being infected with the SARS-CoV-2 virus. IL-1β and IL-6 are significant proinflammatory indicators, and excessive levels of either may cause cytokine release syndrome. In addition, they are a strong predictor of COVID-19 infection.