The trial began in April of 2022, during a period when Iran was experiencing a significant wave of COVID-19. At that time, the potential role of corticosteroids in treating the disease had not yet been emphasized. Thus, the exact role and dose of corticosteroids were unclear. The results of this research showed that patients with mild to moderate ARDS receiving 1000 mg/day pulse therapy of methylprednisolone before starting 1 mg/kg/12 hours methylprednisolone did not experience any increased survival, decreased ICU stay and overall hospital stay or improved rates of mechanical ventilation or non-invasive ventilation (NIV). However, the risk of bacterial pneumonia co-infection was considerably greater in the group receiving large doses of methylprednisolone.
The 2 effective evidence-based treatments that are now in widespread use for hospitalized patients with COVID-19 are systematic corticosteroids and remdesivir (
9,
11,
14). In fact, among immune-modulating agents, steroids have been found to slow the development of respiratory failure and mortality in cases of severe COVID-19 pneumonia with cytokine storm syndrome (
7,
9).
Glucocorticoids exert their suppressive effects on the human immune system by preventing macrophages from performing their phagocytic roles and by reducing the activity and quantity of T cells while having little to no effect on humoral immunity (
15). Rapid Evidence Appraisal for COVID-19 Therapies (REACT), the WHO’s biggest meta-analysis of clinical studies, has shown that systemic steroid therapy among severe COVID-19 patients is helpful in lowering in-hospital mortality (
12,
16).
The WHO has issued recommendations for the use of low-dose steroid therapy in the treatment of severe COVID-19 patients, emphasizing their advantages in reducing mortality and the requirement for mechanical ventilation; while also advising against the use of it in mild to moderate cases (
16). Other studies have shown that early steroid treatment could lower mortality, decrease the number of days that ARDS patients require invasive ventilation, and increase the number of days when organ support is not required (
9-
12,
15,
17,
18). These findings demonstrate once more how systemic steroid therapy might increase the likelihood of survival.
Nevertheless, up until recently, there is no strong consensus agreement on the standards for the amount of steroid administration for COVID-19 patients, and most of the data showing the advantages of corticosteroids in COVID-19 came from observational studies rather than clinical trial studies (
19,
20). Consistent with our findings, previous retrospective observational studies have shown that glucocorticoid pulse treatment does not appear to be more advantageous than lowering dosages in COVID-19 (
21). Moreover, Jeronimo et al. (
22) conducted research on COVID-19 patients with ARDS who received methylprednisolone and found a high mortality rate of around 30%, compared with patients who received low-dose treatment with a fatality rate of 18%. Other studies have found that individuals with comorbid conditions and older age are at higher risk of death while taking high doses of methylprednisolone (
23,
24).
On the other hand, some research has supported the use of methylprednisolone in critically ill patients with severe COVID-19 (
25). In instances of severe SARS-CoV-2 pneumonia treated with 1 to 2 mg/kg/day of methylprednisolone over the course of 7 days, You et al. (
26) principally observed a quicker improvement of oxygen saturation and a shorter duration of fever. Further, high-dose methylprednisolone was found to be superior to dexamethasone in studies by Pinzón et al. (
25) and Ranjbar et al. (
27) in improving clinical conditions and decreasing the need for invasive ventilation. The fact that methylprednisolone could reach into the lungs more extensively rather than dexamethasone may be the cause of this advantageous impact, which would make it more effective in improving lung compliance. Although, in the aforementioned investigations, the mortality rate improvement was not statistically significant. Similarly, several investigations have shown that early methylprednisolone therapy could improve clinical outcomes in hypoxic individuals with more severe illnesses (
28).
It is worth noting that among various types of corticosteroids, we chose to administer methylprednisolone to COVID-19 patients who met the criteria for treatment. Methylprednisolone is a readily accessible, inexpensive corticosteroid that has been used more frequently than other corticosteroids in ARDS studies. Methylprednisolone, an intermediate-acting medication, has a 5-fold potency advantage over short-acting medications such as hydrocortisone. While dexamethasone, a long-acting medication, has a 25-fold advantage over short-acting medications and has been used in several settings due to the COVID-19 pandemic (
25,
29). Additionally, because methylprednisolone has little to no mineralocorticoid action, it will not increase the risk of fluid retention (a sodium/water mismatch), which is typically found in severe ARDS cases (
30).
Our findings revealed that individuals receiving high doses of steroids were at greater risk of developing concurrent bacterial pneumonia. Observational data currently available point to a greater risk of subsequent fungal or bacterial infections after corticosteroid usage in viral syndromes (as was previously seen in influenza) (
31), as well as in compromised immune responses to respiratory syncytial virus (RSV) (
8,
32). In our study, individuals who received methylprednisolone did not have a higher incidence of septic shock. All patients were hospitalized and taking a macrolide and ceftriaxone at the same time, which may have complicated the accurate assessment of this possible adverse effect of corticosteroid treatment. It should be noted that in the treatment of septic shock, corticosteroid medications have been used to increase systemic vascular resistance and enhance mineralocorticoid function, with the goal of restoring effective blood volume (
33,
34).
Regarding the absolute efficacy of corticosteroids in COVID-19, numerous issues remain unresolved. Notably, a recent systematic analysis of corticosteroid trials revealed that MERS-CoV-1 and SARS-CoV-1 had delayed viral clearance. Due to the potential for increased viral shedding after steroid treatment is discontinued, it is advisable to continue such medications for more than 5 days or until clinical improvement is observed, particularly when initiated early in the course of illness. Although we did not have the opportunity to assess this consequence in our investigation, high-dose corticoids have been demonstrated to affect long-term viral shedding (
34). However, this theory needs to be validated, and future studies should include longer virologic follow-ups.
This study had several strengths, including being conducted in a public hospital setting that adhered to appropriate clinical practices. Additionally, it was designed to specifically evaluate the role of adjuvant steroid pulse therapy, which has been rarely assessed in previous literature (
13). However, the study also had several limitations, including (1) a relatively small sample size, which limited our ability to more accurately evaluate minor differences between the case and control groups; (2) a single-center setting; (3) a relatively high overall fatality rate (33.7%) compared to other similar studies, which may be partially explained by the participant demographics and the higher prevalence of co-morbidities; and 4) a lack of data to estimate the impact of these treatment regimens on leading complications of COVID-19, such as pulmonary fibrosis.
5.1. Conclusions
The use of methylprednisolone pulse therapy during the first 3 days of hospitalization, before initiating 1 mg/kg/12 hours methylprednisolone, was not sufficient to improve the prognosis, hospital events, and final outcomes in COVID-19 patients. Our analysis also showed that pulse therapy with methylprednisolone increased bacterial co-infection pneumonia in hospitalized patients with COVID-19. Further studies are needed to determine whether clinicians should consider increasing the dosage of steroids in the treatment of COVID-19 or if caution is warranted due to the increased risk of concurrent bacterial pneumonia. Further, more evaluations of the prolonged adverse effects, which are frequently dose-dependent, could help clinicians to decide between regimens if both of the dosing formulations are verified to have equivalent efficacies in clinical outcomes.