Clinical characteristics of SARS-CoV-2 infection in patients with chronic hepatitis B during interferon antiviral therapy

Highlights

• •Scientific question: Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and its clinical manifestations are diverse. It is still unclear whether the use of interferons is related to the infection of the novel coronavirus in patients with chronic hepatitis B (CHB).
• •Evidence before this study: Interferon is used to treat COVID-19 patients due to its antiviral effect. Studies have found that in SARS-CoV-2 infection, interferon regulates the immune response of the body by transmitting key signals that promote antiviral cellular stress. Analysis of patients with moderate to severe COVID-19 showed that the ability of SARS-CoV-2-specific T cells to produce interferon (IFN) and undergo clonal expansion is significantly correlated with the resolution of the patient’s disease.
• •New findings: Interferon therapy reduces SARS-CoV-2 infection rates in CHB patients. Although SARS-CoV-2 vaccination in CHB patients does not decrease COVID-19 incidence, it may potentially mitigate COVID-19 progression or reduce disease severity.
• •Significance of this study: Based on our study of CHB patients with SARS-CoV-2 infection, IFN therapy may reduce the incidence of SARS-CoV-2 infection in this population, thereby establishing the foundation for combined prevention and therapeutic strategies incorporating IFN treatment.

Abstract

To investigate the clinical characteristics of coronavirus disease 2019 (COVID-19) infection in patients with chronic hepatitis B (CHB) during interferon antiviral therapy and to explore the correlation between interferon use and COVID-19 infection and clinical indicators in these patients. A retrospective study was conducted on 477 Patient with CHB who visited the Second Hepatology Department of Ditan Hospital from December 2022 to February 2023. Patients were divided into an interferon group and a nucleoside analogue group based on whether they received interferon treatment. COVID-19 infection and fever duration were the primary indicators, while blood routine and liver function were the secondary indicators. Differences in COVID-19 infection rate, fever duration, and related laboratory tests between the two groups were compared. There were 184 patients in the interferon group and 293 patients in the nucleoside analogue group. The COVID-19 infection rate was 73.91 % (136/184) in the interferon group and 92.15 % (270/293) in the nucleoside analogue group, with a statistically significant difference (χ² = 29.67, P < 0.001). After COVID-19 infection, the fever duration was shorter in the interferon group than in the nucleoside analogue group, with a statistically significant difference (χ² = 130.15, P < 0.001). Logistic regression analysis showed that interferon use was an independent influencing factor for COVID-19 (odds ratio = 0.25, 95 % confidence interval: 0.14–0.43, P < 0.001). Compared with the nucleoside analogue group, the levels of white blood cells, neutrophils, lymphocytes, platelets, and aminotransferases were significantly different in the interferon group (P < 0.05). There were no differences between the two groups in creatinine and cardiac enzymes (P > 0.05). Interferon therapy can reduce the COVID-19 infection rate in patient with CHB and shorten the fever duration to a certain extent.

1. Introduction

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for coronavirus disease 2019 (COVID-19), has triggered a global pandemic. It has become the second leading cause of age − standardized death globally, with 99.4 deaths per 100,000 people. The pandemic has also led to an increase in the mortality rate of other related diseases, reducing the global life expectancy by 1.6 years, and it is still prevalent worldwide [1]. SARS-CoV-2 is a single − stranded ribonucleic acid (RNA) β − coronavirus that mainly causes disease by binding its spike protein to the angiotensin − converting enzyme receptor and subsequent membrane fusion [2,3]. During this process, the release of type I interferon (IFN-I) is involved, which blocks viral replication and spread. IFN-I is one of the first cytokines produced during viral infection to promote the body's immune response [4]. interferon α/β (IFN-α/β) are broad − spectrum antiviral agents that, in addition to activating the innate immune system, inhibit viral replication by interacting with toll − like receptors [5]. Both IFNα and IFNβ have demonstrated antiviral activity against Middle East respiratory syndrome coronavirus (MERS-CoV) and severe acute respiratory syndrome coronavirus (SARS-CoV) in vitro [6]. Several studies have shown that early interferon treatment is associated with a good clinical response in COVID-19 patients [7]. However, it has also been reported that the use of interferons is highly selective and not beneficial for all patients, but may be useful for certain subgroups [8]. This study aims to explore the characteristics of interferon treatment on the COVID-19 infection rate and clinically relevant indicators in patients with chronic hepatitis B (CHB), providing a basis for the prevention or treatment of COVID-19 in these patients after infection.

2. Materials and methods

2.1. Study subjects

This study is a retrospective cohort study. The study subjects were selected from patients with CHB who visited the Second Hepatology Clinic of Beijing Ditan Hospital, Capital Medical University, from December 2022 to February 2023. Inclusion criteria were as follows: (1) HBsAg positivity for more than 6 months; (2) patients undergoing antiviral treatment; (3) no limitation on HBeAg status and HBV DNA level; (4) age between 18 and 65 years old [9]. Exclusion criteria were as follows: (1) presence of other liver diseases such as autoimmune hepatitis, alcoholic hepatitis, and liver cancer; (2) pregnant or breastfeeding women; (3) patients diagnosed with liver cirrhosis; (4) patients with severe lesions in other organs or mental disorders; (5) patients with severe infectious diseases such as acquired immune deficiency syndrome; (6) patients with other malignant tumors and an estimated survival period of less than 1 year. Patients were divided into an interferon group and a nucleoside analogue group based on whether they received interferon. The interferon group consisted of patients who received interferon therapy (including pegylated interferon a-2b 135 µg/180 µg) combined with nucleoside analogue therapy [including Entecavir (ETV) / Tenofovir disoproxil fumarate (TDF) / Tenofovir alafenamide fumarate (TAF)] for more than 3 months. The nucleoside analogue group consisted of patients who only received nucleoside analogue therapy (including ETV / TDF / TAF) for more than 3 months.

2.2. Collection of demographic data and treatment information

All researchers involved in the survey received unified training before the survey. The research background, objectives, methods, potential risks, and compensation were introduced to the subjects. After obtaining the subjects' consent and signed informed consent forms, information was collected. The subjects answered relevant questions according to the research questionnaire, which mainly included their basic information, such as name, gender, age, COVID-19 vaccination status and the number of doses received, whether it was the first COVID-19 infection at the time of the survey, and past medical history.

2.3. Diagnostic criteria for COVID-19 infection

The diagnostic criteria for COVID-19 infection were based on the Diagnosis and Treatment Protocol for COVID-19 (Trial Version 10) [10], which included: (1) relevant clinical manifestations of COVID-19 infection; (2) one or more of the following pathogen and serological examination results: positive COVID-19 nucleic acid test, positive COVID-19 antigen test. According to the patients with CHB who visited the Second Hepatology Clinic of Beijing Ditan Hospital, Capital Medical University, during the study period, patients with relevant manifestations of COVID-19 infection and positive COVID-19 nucleic acid test or positive COVID-19 antigen test were diagnosed with COVID-19 infection.

2.4. Detection of clinical indicators

All tests were performed at the Laboratory Center of Beijing Ditan Hospital. Liver function and kidney function indicators were measured using a Hitachi fully automatic biochemistry analyzer (Ltd., Japan), and the samples were tested on the day of collection. Liver function indicators included alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), direct bilirubin (DBIL), cholinesterase (CHE), and albumin (ALB). Kidney function indicators included creatinine (CREA) and urea nitrogen (UREA). Blood cell count indicators, including platelet count (PLT) and hemoglobin (HGB), were measured using a Beckman Coulter fully automatic blood cell analyzer (COURTER LH755), and the blood samples were tested on the day of collection.

2.5. Statistical analysis

Statistical analysis was performed using R language R 4.2 software. Continuous variables were first tested for normality using the Shapiro-Wilk test. Those conforming to a normal distribution were expressed as mean ± standard deviation (SD), while those not conforming to a normal distribution were expressed as median (P₂₅, P₇₅). For measurement data, t-tests or Mann-Whitney U-tests were used for comparisons between the two groups. For count data, chi-square (χ²) tests or Fisher's exact tests were used for comparisons between the two groups. Logistic regression analysis was used to identify factors associated with COVID-19 infection. A P-value of less than 0.05 was considered statistically significant.

3. Results

3.1. Basic information

A total of 477 participants were included in this study. Based on whether interferon therapy was used, they were divided into an interferon group and a nucleoside analogue group, with 184 cases in the interferon group and 293 cases in the nucleoside analogue group. No statistically significant differences were observed between the two groups in terms of gender, age, vaccination status, disease duration, underlying diseases, and body mass index (P > 0.05), indicating that the two groups were comparable (Table 1).

Table 1.

Comparison of baseline data between NAs and IFN groups.

Items	NAs group (n = 293)	IFN group (n = 184)	P-value
Age (year), mean ± SD	43.41 ± 10.36	44.28 ± 7.86	0.301
Gender, n (%)			0.673
Male	184 (62.80)	112 (60.87)
Female	109 (37.20)	72 (39.13)
Number of SARS-CoV-2 vaccination, n (%)			0.658
0	35 (11.95)	20 (10.87)
1	4 (1.37)	0 (0.00)
2	35 (11.95)	24 (13.04)
3	216 (73.72)	139 (75.54)
4	3 (1.02)	1 (0.54)
First infection withSARS-CoV-2, n (%)			0.329
No	59 (20.14)	44 (23.91)
Yes	234 (79.86)	140 (76.09)
Disease course (week), n (%)			0.990
< 1	161 (54.95)	101 (54.89)
> 1	132 (45.05)	83 (45.11)
DM, n (%)	24 (8.19)	18 (9.78)	0.550
HTN, n (%)	21 (7.17)	15 (8.15)	0.692
CHD, n (%)	5 (1.71)	3 (1.63)	1.000
BMI (kg/m2), mean ± SD	22.41 ± 1.80	22.34 ± 1.72	0.673

Abbreviations: SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; SD, standard deviation; NAs, nucleoside analogs; IFN, interferon; DM, diabetes mellitus; CHD, coronary heart disease; HTN, hypertension; BMI, body mass index.

3.2. Correlation analysis of interferon use with clinical biochemical indicators, COVID-19 infection, and fever duration

In the comparison of laboratory indicators between the two groups, the levels of white blood cells, neutrophils, lymphocytes, and platelets were all lower in the interferon group than in the nucleoside analogue group, while the levels of aminotransferases were higher in the interferon group than in the nucleoside analogue group. The differences were all statistically significant (P < 0.05). However, there were no statistically significant differences between the two groups in the levels of albumin, creatinine, and cardiac enzymes (P > 0.05) (Table 2, Table 3).

Table 2.

Analysis of clinical and biochemical related indicators of NAs and IFN groups.

Items	NAs group (n = 293)	IFN group (n = 184)	P-value
WBC (×109/L)	5.16 (3.95, 6.38)	3.58 (2.75, 4.96)	<0.001
NE (×109/L)	3.01 (2.21, 3.83)	2.03 (1.36, 2.93)	<0.001
LY (×109/L)	1.66 (1.29, 2.18)	1.25 (0.94, 1.57)	<0.001
PLT (×109/L)	199.50 (142.00, 237.75)	153.50 (110.00, 219.00)	<0.001
HGB (g/L)	145.50 (131.00, 158.00)	137.00 (121.00, 149.25)	<0.001
ALT (U/L)	23.80 (17.00, 40.90)	31.65 (20.78, 53.48)	<0.001
AST (U/L)	21.00 (17.60, 28.00)	27.45 (20.32, 40.50)	<0.001
ALB (g/L)	45.80 (43.80, 47.60)	45.30 (43.60, 47.40)	0.506
Cr (µmol/L)	66.20 (56.12, 74.00)	65.45 (54.15, 73.70)	0.323
CK-MB (U/L)	13.70 (10.17, 23.15)	11.35 (8.85, 21.18)	0.167
LDH (U/L)	169.70 (152.48, 185.48)	171.55 (159.27, 195.53)	0.500

Data were expressed by median (P₂₅, P₇₅). Abbreviations: NAs, nucleoside analogs; IFN, interferon; WBC, white blood cell; NE, neutrophils; LY, Lymphocyte; PLT, platelet; HGB, hemoglobin; ALT, alanine aminotransferase; AST, aspartate aminotransferase; ALB, albumin; Cr, creatinine; CK-MB, creatine kinase-myocardial band; LDH, lactate dehydrogenase; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.

Table 3.

Comparison of SARS-CoV-2 infection and fever time between NAs and IFN groups.

Items	Total (n = 477)	NAs group (n = 293)	IFN group (n = 184)	χ2 value	P-value
Novel coronavirus infection, n (%)				29.67	<0.001
No	71 (14.88)	23(7.85)	48 (26.09)
Yes	406 (85.12)	270(92.15)	136 (73.91)
Fever duration (d), n (%)				130.15	<0.001
1	16 (3.36)	6 (2.06)	10 (5.43)
2	133 (27.88)	42 (14.33)	91 (49.46)
3	171 (35.85)	96 (32.76)	75 (40.76)
> 4	157 (32.91)	149 (50.85)	8 (4.35)

χ², Chi-square test. Abbreviations: SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; NAs, nucleoside analogs; IFN, interferon.

3.3. Logistic regression analysis of interferon therapy, underlying diseases, body mass index (BMI), and COVID-19 vaccination on COVID-19 infection

Univariate logistic regression analysis showed that a lower COVID-19 infection rate in patients with CHB was associated with ongoing interferon therapy. Interferon therapy significantly reduced the COVID-19 infection rate [odds ratio (OR) = 0.24, 95 % confidence interval (CI): 0.14–0.41, P < 0.001] (Table 4). COVID-19 vaccination, whether it was the first COVID-19 infection, past underlying diseases, and BMI were not associated with COVID-19 infection (P > 0.05). Multivariate logistic regression analysis indicated that interferon therapy was an independent protective factor against COVID-19 infection and significantly reduced the infection rate (OR = 0.25, 95 % CI: 0.14–0.43, P < 0.001) (Table 4).

Table 4.

Logistic regression analysis of factors related to COVID-19 infection.

Items	Univariate analysis		Multivariate analysis
	P-value	OR (95% CI)	P-value	OR (95% CI)
Interferon therapy	< 0.001	0.24 (0.14–0.41)	< 0.001	0.25 (0.14–0.43)
Number of SARS-CoV-2 vaccination
0		1.00 (Reference)	-	-
1	0.985	0.98 (0.42–3.16)	-	-
2	0.915	0.95 (0.34–2.65)	-	-
3	0.984	0.99 (0.44–2.22)	-	-
4	0.098	0.17 (0.02–1.39)	-	-
DM	0.067	0.45 (0.19–1.06)	0.219	0.56 (0.23–1.40)
CHD	0.089	0.28 (0.07–1.21)	0.116	0.45 (0.16–1.22)
HTN	0.116	0.35 (0.14–0.89)	0.057	0.23 (0.05–1.04)
BMI (kg/m2)
< 18		1.00 (Reference)		1.00 (Reference)
18-24	0.834	1.18 (0.25–5.52)	0.680	1.40 (0.28–6.90)
> 24	1.000	1.00 (0.19–5.15)	0.945	1.06 (0.19–5.79)

Abbreviations: COVID-19, coronavirus disease 2019; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; DM, diabetes mellitus; CHD, coronary heart disease; HTN, hypertension; BMI, body mass index; OR, odds ratio; CI, confidence interval.

3.4. Comparison of clinical indicators between COVID-19 infected and uninfected groups

In the interferon group, there were statistically significant differences in the levels of neutrophils and platelets between the COVID-19 infected group and the uninfected group (P < 0.05), as shown in Fig. 1 (Fig. 1B and 1C). Patients in the infected group had higher levels of neutrophils and platelets. However, in the nucleoside analogue group, there were no statistically significant differences in the levels of white blood cells, neutrophils, platelets, lymphocytes, and hemoglobin between the infected and uninfected groups (P > 0.05).

Fig. 1.

Comparison of clinical indexes between IFN treatment group and NAs treatment group [A) Leucocyte; B) Neutrophil; C) Platelets; D) Lymphocytes; E) Hemoglobin]. Boxes represent the interquartile range (25^th -75^th percentile) with median lines; whiskers indicate the minimum and maximum values. Group comparisons were performed using the Mann -Whitney U test. Abbreviations: COVID-19, coronavirus disease 2019; IFN, interferon; NAs, nucleoside analogs. *P < 0.05; ns, no significance.

4. Discussion

4.1. Antiviral mechanism of interferons

The application of IFN in the antiviral treatment of CHB patients is well − established. IFN is a crucial component of the antiviral innate immune response and serves as one of the essential broad − spectrum antiviral agents. It can inhibit viral replication and modulate immune responses. IFN-I (such as IFN-α and IFN-β) are central components of the antiviral innate immune response, exhibiting broad-spectrum antiviral effects by directly inhibiting viral replication and simultaneously modulating the host's immune reactions [11]. Type I and Type III IFNs are induced by the interaction of viral characteristic structures (such as viral messenger RNA) with host cell pathogen − pattern recognition receptors (e.g., Toll-like receptors and retinoic acid-inducible gene I [RIG-I] receptors) [12]. Upon recognizing viral signals, host cells initiate a series of complex intracellular signaling events, leading to the activation of inflammatory transcription factors (nuclear factor kappa B [NF − κB]) and interferon regulatory factors interferon regulatory factor 3 (IRF3) and IRF7. This activation ultimately mediates the transcription and expression of inflammatory cytokines (e.g., interleukin [IL]-1, IL-6, and ‌tumor necrosis factor [TNF] − α) and IFNs. Subsequently, IFN molecules are released into the surrounding tissues and bind to IFN receptors in a paracrine or autocrine manner. Interferon alpha/beta receptor (IFNAR) is widely distributed and expressed in various cell types, while interferon lambda receptor (IFNLR) expression is limited, mainly enriched on the surface of epithelial cells. Together with other intracellular transcription factors (e.g., IRF9), they induce the expression of a large number of interferon − stimulated genes (ISGs), helping cells enter an antiviral state [29]. Additionally, IFN-I can enhance the activity of virus − specific T cells, promoting their clearance of infected cells. It can also enhance B cell activation and antibody production, aiding in virus neutralization. Recent studies have found that interferon − induced protein Interferon − induced transmembrane protein 3 (IFIT3) has a potential protective effect in COVID - 19 infection. In uninfected or asymptomatic individuals, IFIT3 gene expression is significantly up-regulated, especially in those repeatedly exposed to COVID-19 infection [13]. This up-regulation may enhance the interferon signaling pathway, inhibit viral replication, and thus reduce the risk of infection. IFIT3 can also regulate immune-related molecules or pathways within the antiviral innate immune framework to inhibit viral replication.

4.2. Clinical applications of interferons

IFN has demonstrated clinical efficacy in the treatment of various viral infections and has been utilized in the treatment of COVID-19 patients [14,15]. A study, conducted by dozens of hospitals in Brazil and Canada, achieved its primary endpoint [16]. Initiated in June 2021, the study included outpatients with symptoms appearing within 7 days, who received a single subcutaneous injection of long-acting IFN-λ (180 μg). The study results showed a significant reduction in the proportion of hospitalization and emergency visits (primary endpoint) in the single-dose long-acting IFN-λ injection group compared to the control group (2.7 % vs 5.6 %), and a notable decrease in the proportion of patients who died of COVID-19 within 28 days (secondary endpoint) (0.1 % vs 0.4 %), thus confirming the effectiveness of IFN in the treatment of COVID-19. IFN can transmit secondary signals for antiviral cell stress development [17]. A study analyzing the T cell response in patients with moderate and severe COVID-19 found that the production and clonal expansion of SARS-CoV-2-specific T cells were associated with disease resolution in COVID-19 patients [18]. However, SARS-CoV-2 inhibits the production and activity of IFN [19]. The continuous activation of the IFN-I signaling pathway can lead to the production of various inflammatory cells, including monocytes, macrophages, and neutrophils, which release a large amount of inflammatory factors, resulting in severe lung damage and multi-organ failure [[20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30]]. Therefore, early use of IFN can prevent the rapid spread of the virus and the subsequent cytokine storm that causes the most damage. Multiple studies have shown that IFN has an immune-protective effect in the early stage of COVID-19, while it has an immune-damaging effect that exacerbates inflammation in the late stage. A retrospective study on IFN treatment in COVID-19 patients showed that, compared with patients treated with antiviral protease inhibitors, patients with severe conditions treated with nebulized IFN had a shorter hospital stay, but there was no benefit for patients with moderate diseases [7]. Treatment with IFN-α2b with or without arbidol significantly reduced the duration of detectable virus in the upper respiratory tract and in parallel reduced duration of elevated blood levels for the inflammatory markers IL-6 and C-reactive protein [21]. It is evident that the treatment effect varies with different disease severities and clinical backgrounds. Patients with CHB included in this study were all mild-case COVID-19 infectors, and their past medical history was relatively simple. Therefore, the application of IFN in the antiviral treatment of patients with CHB needs to be further verified by prospective, large-sample, multi-center, and double-blind controlled trials to draw more objective conclusions. Additionally, studies have found that IFN treatment can reduce the symptoms, incidence of severe diseases, and mortality in COVID-19 patients [14,22]. In this study, the IFN treatment group had a lower COVID-19 infection rate [136 (73.91 %) vs 270 (92.15 %), χ² = 29.67, P < 0.001], indicating that it may have a certain role in preventing COVID-19 infection.

4.3. Analysis of the efficacy of SARS-CoV-2 vaccination in patients with CHB

Currently, SARS-CoV-2 vaccination is safe and effective [23]. However, it may induce autoimmune hepatitis − like manifestations in susceptible individuals. This has caused concern among patients with chronic liver diseases, such as CHB, autoimmune liver disease, or those in an active disease state. These patients are worried that vaccination may not achieve the expected preventive effect. Logistic regression analysis in this study showed that SARS-CoV-2 vaccination was not a factor related to COVID-19 infection, suggesting that vaccination may not effectively prevent COVID-19 infection. This may be related to the fact that all the samples selected in this study were patients with CHB, which has a unique immune response. Patients with CHB have continuously decreasing immunity due to the continuous replication of the virus, liver cell damage, reduced blood cells, anemia, decreased white blood cells and platelets, and a sustained catabolic state. The effectiveness of the vaccine against the Omicron BA.1 and BA.2 variants is low, and the humoral immune response decreases significantly over time, with a risk of infection after vaccination. However, as the number of vaccinations increases, it may have a positive impact on reducing the occurrence of COVID-19 or alleviating patients' severe symptoms. This is the limitation of this trial, which did not include patients' symptoms after infection and COVID-19 patients with severe pneumonia. The patients included in this study were outpatients visiting the Second Hepatology Department, all of whom were mild- case COVID-19 infectors. There is a lack of data to support the study on alleviating severe symptoms, but conclusions can be drawn from previous studies. Professor Wong Chi-kee's team at the University of Hong Kong, China, conducted a retrospective territory-wide cohort study on 1,175,277 SARS-CoV-2-infected patients, assessing the impact of vaccination on long − term health consequences after infection. Compared with patients who were unvaccinated or vaccinated 30–90 days after infection or incompletely vaccinated, patients who were fully vaccinated or had received booster doses had a lower risk of health consequences (including major cardiovascular diseases and all-cause mortality). From 271 and 91 days after infection, fully vaccinated and booster-vaccinated patients did not have a higher risk of health consequences, while unvaccinated and incompletely vaccinated patients continued to have a greater risk of clinical sequelae for up to one year after SARS-CoV-2 infection [24].

4.4. Side effects associated with interferon therapy

Concurrently, studies have demonstrated that increased expression of IFN-α and IFN-β in the bronchoalveolar lavage fluid (BALF) of COVID-19 patients is associated with the incidence rate [25]. Over-activation of the IFN-I signaling pathway may lead to uncontrolled inflammatory responses, exacerbating lung tissue damage [26]. IFN-I has a potential pathogenic mechanism during SARS-CoV-2 infection. Therefore, the widespread use of interferon in the prevention and treatment of COVID-19 infection may still require further research with large-scale cohorts and long-term follow-up. This research should include patients with various clinical types of COVID-19 infection, not limited to mild cases, to analyze the optimal subgroup of patients for interferon application. Severe COVID-19 infection is characterized by a sharp increase in immature neutrophils, which is associated with enhanced systemic inflammation [27]. In addition, neutrophils are associated with the occurrence of acute respiratory distress syndrome related to COVID-19 and thrombosis induced by neutrophil extracellular traps, representing a potential therapeutic target for COVID-19 disease [28]. In this trial, the infected group had higher levels of white blood cells, neutrophils, and platelets than the uninfected group, showing the changes in peripheral blood cells under enhanced systemic inflammatory response.Previous studies have shown that in CHB patients treated with interferon, the peripheral blood cells began to decrease significantly from the second week of treatment, which is consistent with the lower levels of neutrophils and platelets in the uninfected group in this trial compared to the infected group. The reason may be related to the use of interferon in the uninfected group.

5. Conclusion

In summary, the use of interferon therapy reduces the COVID-19 infection rate in CHB patients. As the most critical broad-spectrum antiviral component, the role of IFN in COVID-19 has been extensively studied over the past few years, generating substantial data. Most clinical trials were initiated with research protocols designed under limited understanding of disease mechanisms, resulting in a degree of blindness. These studies involved confounder across multiple aspects, including patient selection, administration routes, drug types, and dosages. Among these, timing of administration, dosage, delivery methods, and concurrent glucocorticoid use likely constitute the most critical influencing factors. Despite contradictions in mechanistic and clinical trial data, the scientific community has reached clear consensus: the clinical outcomes of COVID-19 infection are closely associated with IFN levels and their temporal dynamics post-infection. Early IFN deficiency is a key factor in severe progression following COVID-19 infection. IFN demonstrates immunoprotective effects during early COVID-19 stages but exacerbates inflammatory immune damage in later phases. To refine IFN's precise role in COVID-19 management and update clinical guidelines, high-quality, mechanism-guided prospective clinical trials are imperative. Specifically, future clinical research on IFN against COVID-19 must rigorously control the aforementioned confounder in trial design. Only through such methodological rigor can the scientific community derive more compelling conclusions.

Ethics statement

The Ethics Committee of Beijing Ditan Hospital (No. DTEC‐KY2023‐009‐01) reviewed the research. The clinicaltrials.gov ID of this research was NCT05792878.

CRediT authorship contribution statement

Shiyu Wang: Writing – review & editing, Writing – original draft, Data curation. Ziyu Zhang: Writing – review & editing, Writing – original draft, Data curation. Xinxin Li: Writing – review & editing, Writing – original draft, Data curation. Wen Deng: Writing – review & editing, Writing – original draft, Data curation. Yaqin Zhang: Visualization, Investigation, Data curation. Weihua Cao: Visualization, Investigation, Data curation. Xin Wei: Supervision, Data curation. Zixuan Gao: Supervision, Data curation. Linmei Yao: Supervision, Data curation. Shuojie Wang: Supervision, Data curation. Yao Xie: Software, Supervision, Methodology, Conceptualization. Minghui Li: Writing – review & editing, Software, Supervision, Methodology, Conceptualization.

Conflcit of interest statement

The authors declare that there are no conflicts of interest.