Cytokine Storms: Understanding COVID-19.

The elevated circulating levels of cytokines associated with a variety of infectious and immune-mediated conditions are frequently termed a cytokine storm. Here, we explain the protective functions of cytokines in "ideal" responses; the multi-factorial origins that can drive these responses to become pathological; and how this ultimately leads to vascular damage, immunopathology, and worsening clinical outcomes.

Plasma microbial cell-free DNA following chimeric antigen receptor T cell therapy in pediatric patients with relapsed/refractory leukemia.

Chimeric antigen receptor (CAR) T cell therapy is a promising treatment for pediatric patients with relapsed or refractory B cell acute lymphoblastic leukemia (R/R B ALL). Cytokine release syndrome (CRS) is a common toxicity after CAR T cell therapy and fever is often the first symptom. Differentiating CRS from infection after CAR T cell therapy can be challenging. Plasma microbial cell free DNA (mcfDNA) is a novel diagnostic tool which allows for qualitative and quantitative assessment of over 1000 organisms. This pilot study sought to characterize mcfDNA results in pediatric patients with R/R B ALL in the first 2 months after CAR T cell therapy.

SARS-CoV-2 nucleocapsid protein, rather than spike protein, triggers a cytokine storm originating from lung epithelial cells in patients with COVID-19.

PURPOSE: The aim of this study was to elucidate the factors associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that may initiate cytokine cascades and correlate the clinical characteristics of patients with coronavirus disease 2019 (COVID-19) with their serum cytokine profiles. METHODS: Recombinant baculoviruses displaying SARS-CoV-2 spike or nucleocapsid protein were constructed and transfected into A549 cells and THP-1-derived macrophages, to determine which protein initiate cytokine release. SARS-CoV-2-specific antibody titers and cytokine profiles of patients with COVID-19 were determined, and the results were associated with their clinical characteristics, such as development of pneumonia or length of hospital stay. RESULTS: The SARS-CoV-2 nucleocapsid protein, rather than the spike protein, triggers lung epithelial A549 cells to express IP-10, RANTES, IL-16, MIP-1α, basic FGF, eotaxin, IL-15, PDGF-BB, TRAIL, VEGF-A, and IL-5. Additionally, serum CTACK, basic FGF, GRO-α, IL-1α, IL-1RA, IL-2Rα, IL-9, IL-15, IL-16, IL-18, IP-10, M-CSF, MIF, MIG, RANTES, SCGF-ß, SDF-1α, TNF-α, TNF-ß, VEGF, PDGF-BB, TRAIL, ß-NGF, eotaxin, GM-CSF, IFN-α2, INF-γ, and MCP-1 levels were considerably increased in patients with COVID-19. Among them, patients with pneumonia had higher serum IP-10 and M-CSF levels than patients without. Patients requiring less than 3 weeks to show negative COVID-19 tests after contracting COVID-19 had higher serum IP-10 levels than the remaining patients. CONCLUSION: Our study revealed that nucleocapsid protein, lung epithelial cells, and IP-10 may be potential targets for the development of new strategies to prevent, or control, severe COVID-19.

Hidradenitis Suppurativa Found Associated With Cytokine Storm.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic inflammatory disease that generates multiple cytokines. Here, we present an example of the cytokines forming a cytokine storm and its effects on the patient. CASE PRESENTATION: We report the case of a 55-year-old man who had severe but stable HS. Serum samples were collected from the patient and extraordinarily elevated cytokine concentrations were identified in the patient's serum.  Conclusion: Cytokine storms may be a condition associated with HS posing additional risk to patient survival. J Drugs Dermatol. 2024;23(5):e134-e136.     doi:10.36849/JDD.7860R1e.

NK Cell-Derived IL-10 Supports Host Survival during Sepsis.

The dysregulated sepsis-induced cytokine storm evoked during systemic infection consists of biphasic and interconnected pro- and anti-inflammatory responses. The contrasting inflammatory cytokine responses determine the severity of the septic event, lymphopenia, host survival, and the ensuing long-lasting immunoparalysis state. NK cells, because of their capacity to elaborate pro- (i.e., IFN-γ) and anti-inflammatory (i.e., IL-10) responses, exist at the inflection of sepsis-induced inflammatory responses. Thus, NK cell activity could be beneficial or detrimental during sepsis. In this study, we demonstrate that murine NK cells promote host survival during sepsis by limiting the scope and duration of the cytokine storm. Specifically, NK cell-derived IL-10, produced in response to IL-15, is relevant to clinical manifestations in septic patients and critical for survival during sepsis. This role of NK cells demonstrates that regulatory mechanisms of classical inflammatory cells are beneficial and critical for controlling systemic inflammation, a notion relevant for therapeutic interventions during dysregulated infection-induced inflammatory responses.

Critical Determinants of Cytokine Storm and Type I Interferon Response in COVID-19 Pathogenesis.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), a rapidly evolving pandemic worldwide with at least 68 million COVID-19-positive cases and a mortality rate of about 2.2%, as of 10 December 2020. About 20% of COVID-19 patients exhibit moderate to severe symptoms. Severe COVID-19 manifests as acute respiratory distress syndrome (ARDS) with elevated plasma proinflammatory cytokines, including interleukin 1ß (IL-1ß), IL-6, tumor necrosis factor α (TNF-α), C-X-C motif chemokine ligand 10 (CXCL10/IP10), macrophage inflammatory protein 1 alpha (MIP-1α), and chemokine (C-C motif) ligand 2 (CCL2), with low levels of interferon type I (IFN-I) in the early stage and elevated levels of IFN-I during the advanced stage of COVID-19. Most of the severe and critically ill COVID-19 patients have had preexisting comorbidities, including hypertension, diabetes, cardiovascular diseases, and respiratory diseases. These conditions are known to perturb the levels of cytokines, chemokines, and angiotensin-converting enzyme 2 (ACE2), an essential receptor involved in SARS-CoV-2 entry into the host cells. ACE2 downregulation during SARS-CoV-2 infection activates the angiotensin II/angiotensin receptor (AT1R)-mediated hypercytokinemia and hyperinflammatory syndrome. However, several SARS-CoV-2 proteins, including open reading frame 3b (ORF3b), ORF6, ORF7, ORF8, and the nucleocapsid (N) protein, can inhibit IFN type I and II (IFN-I and -II) production. Thus, hyperinflammation, in combination with the lack of IFN responses against SARS-CoV-2 early on during infection, makes the patients succumb rapidly to COVID-19. Therefore, therapeutic approaches involving anti-cytokine/anti-cytokine-signaling and IFN therapy would favor the disease prognosis in COVID-19. This review describes critical host and viral factors underpinning the inflammatory "cytokine storm" induction and IFN antagonism during COVID-19 pathogenesis. Therapeutic approaches to reduce hyperinflammation and their limitations are also discussed.

Divergent impacts of tocilizumab and colchicine in COVID-19-associated coagulopathy: the role of alpha-defensins.

Patients who are severely affected by coronavirus disease 2019 (COVID-19) may develop a delayed onset 'cytokine storm', which includes an increase in interleukin-6 (IL-6). This may be followed by a pro-thrombotic state and increased D-dimers. It was anticipated that tocilizumab (TCZ), an anti-IL-6 receptor monoclonal antibody, would mitigate inflammation and coagulation in patients with COVID-19. However, clinical trials with TCZ have recorded an increase in D-dimer levels. In contrast to TCZ, colchicine reduced D-dimer levels in patients with COVID-19. To understand how the two anti-inflammatory agents have diverse effects on D-dimer levels, we present data from two clinical trials that we performed. In the first trial, TCZ was administered (8 mg/kg) to patients who had a positive polymerase chain reaction test for COVID-19. In the second trial, colchicine was given (0·5 mg twice a day). We found that TCZ significantly increased IL-6, α-Defensin (α-Def), a pro-thrombotic peptide, and D-dimers. In contrast, treatment with colchicine reduced α-Def and Di-dimer levels. In vitro studies show that IL-6 stimulated the release of α-Def from human neutrophils but in contrast to colchicine, TCZ did not inhibit the stimulatory effect of IL-6; raising the possibility that the increase in IL-6 in patients with COVID-19 treated with TCZ triggers the release of α-Def, which promotes pro-thrombotic events reflected in an increase in D-dimer levels.

Cytokine profiles in the detection of severe lung involvement in hospitalized patients with COVID-19: The IL-8/IL-32 axis.

Coronavirus disease 2019 (COVID-19) is an infectious respiratory disorder caused by a new coronavirus called SARS-CoV-2. The pathophysiology of severe COVID-19 is associated with a "cytokine storm". IL-32 is a key modulator in the pathogenesis of various clinical conditions and is mostly induced by IL-8. IL-32 modulates important inflammatory pathways (including TNF-α, IL-6 and IL-1b), contributing to the pathogenesis of inflammatory diseases. Il-32 was never evaluated before in COVID-19 patients stratifying as mild-moderate and severe patients. A total of 64 COVID-19 patients, 27 healthy controls were consecutively enrolled in the study. Serum concentrations of biomarkers including IL-1ß, IL-10, IFN-γ, TNF-α and IL-6 were quantified by bead-based multiplex analysis and Serum concentration of IL-8 and IL-32 were determined by enzyme-linked immunosorbent assay (ELISA) kits. Interestingly, among the blood parameters, neutrophil and lymphocyte counts were significantly lower in severe COVID-19 patients than in the other, on the contrary, CRP was significantly higher in severe patients than in other groups. The cytokines that best distinguished controls from COVID-19 patients were IL-8 and IL-32, while IL-6 resulted the better variables for discriminate severe group. The best model performance for severe group was obtained by the combination of IL-32, IL-6, IFN-γ, and CRP serum concentration showing an AUC = 0.83. A cut off of 15 pg/ml of IL-6 greatly discriminate survivor from death patients. New insights related to the cytokine storm in COVID-19 patients, highlighting different severity of disease infection.

Castleman disease and TAFRO syndrome.

Although Castleman disease was first described in 1956, this disease includes various conditions, including unicentric Castleman disease with hyaline vascular histology, human herpesvirus-8 (HHV-8) related multicentric Castleman disease, idiopathic multicentric Castleman disease, and mimics of Castleman disease associated with other conditions. To date, Castleman disease remains incompletely understood due to its rareness and difficulties in clinical and pathological diagnosis. TAFRO syndrome was reported in Japan in 2010. Because lymph node histology is similar in patients with TAFRO syndrome and Castleman disease, TAFRO syndrome is described as a related disorder of Castleman disease. Clinically, however, these conditions differ markedly. Although elevated interleukin-6 (IL-6) expression is characteristic of Castleman disease, increased expression of IL-6 may occur in patients with other diseases, making elevated IL-6 unsuitable for differential diagnosis. Further understanding of these disorders requires the identification of novel disease-specific biomarkers. This review article therefore outlines the characteristics of Castleman disease and TAFRO syndrome.

Circulating Markers of Neutrophil Extracellular Traps Are of Prognostic Value in Patients With COVID-19.

OBJECTIVE: The full spectrum of coronavirus disease 2019 (COVID-19) infection ranges from asymptomatic to acute respiratory distress syndrome, characterized by hyperinflammation and thrombotic microangiopathy. The pathogenic mechanisms are poorly understood, but emerging evidence suggest that excessive neutrophil extracellular trap (NET) formation plays a key role in COVID-19 disease progression. Here, we evaluate if circulating markers of NETs are associated with COVID-19 disease severity and clinical outcome, as well as to markers of inflammation and in vivo coagulation and fibrinolysis. Approach and Results: One hundred six patients with COVID-19 with moderate to severe disease were enrolled shortly after hospital admission and followed for 4 months. Acute and convalescent plasma samples as well as plasma samples from 30 healthy individuals were assessed for markers of NET formation: citrullinated histone H3, cell-free DNA, NE (neutrophil elastase). We found that all plasma levels of NET markers were elevated in patients with COVID-19 relative to healthy controls, that they were associated with respiratory support requirement and short-term mortality, and declined to those found in healthy individuals 4 months post-infection. The levels of the NET markers also correlated with white blood cells, neutrophils, inflammatory cytokines, and C-reactive protein, as well as to markers of in vivo coagulation, fibrinolysis, and endothelial damage. CONCLUSIONS: Our findings suggest a role of NETs in COVID-19 disease progression, implicating their contribution to an immunothrombotic state. Further, we observed an association between circulating markers of NET formation and clinical outcome, demonstrating a potential role of NET markers in clinical decision-making, as well as for NETs as targets for novel therapeutic interventions in COVID-19.

Clotting disorder in severe acute respiratory syndrome coronavirus 2.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel human respiratory viral infection that has rapidly progressed into a pandemic, causing significant morbidity and mortality. Blood clotting disorders and acute respiratory failure have surfaced as the major complications among the severe cases of coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 infection. Remarkably, more than 70% of deaths related to COVID-19 are attributed to clotting-associated complications such as pulmonary embolism, strokes and multi-organ failure. These vascular complications have been confirmed by autopsy. This study summarizes the current understanding and explains the possible mechanisms of the blood clotting disorder, emphasizing the role of (1) hypoxia-related activation of coagulation factors like tissue factor, a significant player in triggering coagulation cascade, (2) cytokine storm and activation of neutrophils and the release of neutrophil extracellular traps and (3) immobility and ICU related risk factors.

Hematological changes associated with COVID-19 infection.

BACKGROUND: The unresolved COVID-19 pandemic considerably impacts the health services in Iraq and worldwide. Consecutive waves of mutated virus increased virus spread and further constrained health systems. Although molecular identification of the virus by polymerase chain reaction is the only recommended method in diagnosing COVID-19 infection, radiological, biochemical, and hematological studies are substantially important in risk stratification, patient follow-up, and outcome prediction. AIM: This narrative review summarized the hematological changes including the blood indices, coagulative indicators, and other associated biochemical laboratory markers in different stages of COVID-19 infection, highlighting the diagnostic and prognostic significance. METHODS: Literature search was conducted for multiple combinations of different hematological tests and manifestations with novel COVID-19 using the following key words: "hematological," "complete blood count," "lymphopenia," "blood indices," "markers" "platelet" OR "thrombocytopenia" AND "COVID-19," "coronavirus2019," "2019-nCoV," OR "SARS-CoV-2." Articles written in the English language and conducted on human samples between December 2019 and January 2021 were included. RESULTS: Hematological changes are not reported in asymptomatic or presymptomatic COVID-19 patients. In nonsevere cases, hematological changes are subtle, included mainly lymphocytopenia (80.4%). In severe, critically ill patients and those with cytokine storm, neutrophilia, lymphocytopenia, elevated D-dimer, prolonged PT, and reduced fibrinogen are predictors of disease progression and adverse outcome. CONCLUSION: Monitoring hematological changes in patients with COVID-19 can predict patients needing additional care and stratify the risk for severe course of the disease. More studies are required in Iraq to reflect the hematological changes in COVID-19 as compared to global data.

Characterization of the cytokine storm reflects hyperinflammatory endothelial dysfunction in COVID-19.

BACKGROUND: Physicians treating patients with coronavirus disease 2019 (COVID-19) increasingly believe that the hyperinflammatory acute stage of COVID-19 results in a cytokine storm. The circulating biomarkers seen across the spectrum of COVID-19 have not been characterized compared with healthy controls, but such analyses are likely to yield insights into the pursuit of interventions that adequately reduce the burden of these cytokine storms. OBJECTIVE: To identify and characterize the host inflammatory response to severe acute respiratory syndrome coronavirus 2 infection, we assessed levels of proteins related to immune responses and cardiovascular disease in patients stratified as mild, moderate, and severe versus matched healthy controls. METHODS: Blood samples from adult patients hospitalized with COVID-19 were analyzed using high-throughput and ultrasensitive proteomic platforms and compared with age- and sex-matched healthy controls to provide insights into differential regulation of 185 markers. RESULTS: Results indicate a dominant hyperinflammatory milieu in the circulation and vascular endothelial damage markers within patients with COVID-19, and strong biomarker association with patient response as measured by Ordinal Scale. As patients progress, we observe statistically significant dysregulation of IFN-γ, IL-1RA, IL-6, IL-10, IL-19, monocyte chemoattractant protein (MCP)-1, MCP-2, MCP-3, CXCL9, CXCL10, CXCL5, ENRAGE, and poly (ADP-ribose) polymerase 1. Furthermore, in a limited series of patients who were sampled frequently, confirming reliability and reproducibility of our assays, we demonstrate that intervention with baricitinib attenuates these circulating biomarkers associated with the cytokine storm. CONCLUSIONS: These wide-ranging circulating biomarkers show an association with increased disease severity and may help stratify patients and selection of therapeutic options. They also provide insights into mechanisms of severe acute respiratory syndrome coronavirus 2 pathogenesis and the host response.

IL-6 serum levels predict severity and response to tocilizumab in COVID-19: An observational study.

BACKGROUND: Patients with coronavirus disaese 2019 (COVID-19) can develop a cytokine release syndrome that eventually leads to acute respiratory distress syndrome requiring invasive mechanical ventilation (IMV). Because IL-6 is a relevant cytokine in acute respiratory distress syndrome, the blockade of its receptor with tocilizumab (TCZ) could reduce mortality and/or morbidity in severe COVID-19. OBJECTIVE: We sought to determine whether baseline IL-6 serum levels can predict the need for IMV and the response to TCZ. METHODS: A retrospective observational study was performed in hospitalized patients diagnosed with COVID-19. Clinical information and laboratory findings, including IL-6 levels, were collected approximately 3 and 9 days after admission to be matched with preadministration and postadministration of TCZ. Multivariable logistic and linear regressions and survival analysis were performed depending on outcomes: need for IMV, evolution of arterial oxygen tension/fraction of inspired oxygen ratio, or mortality. RESULTS: One hundred forty-six patients were studied, predominantly males (66%); median age was 63 years. Forty-four patients (30%) required IMV, and 58 patients (40%) received treatment with TCZ. IL-6 levels greater than 30 pg/mL was the best predictor for IMV (odds ratio, 7.1; P < .001). Early administration of TCZ was associated with improvement in oxygenation (arterial oxygen tension/fraction of inspired oxygen ratio) in patients with high IL-6 (P = .048). Patients with high IL-6 not treated with TCZ showed high mortality (hazard ratio, 4.6; P = .003), as well as those with low IL-6 treated with TCZ (hazard ratio, 3.6; P = .016). No relevant serious adverse events were observed in TCZ-treated patients. CONCLUSIONS: Baseline IL-6 greater than 30 pg/mL predicts IMV requirement in patients with COVID-19 and contributes to establish an adequate indication for TCZ administration.

Dysregulated Innate and Adaptive Immune Responses Discriminate Disease Severity in COVID-19.

The clinical spectrum of COVID-19 varies and the differences in host response characterizing this variation have not been fully elucidated. COVID-19 disease severity correlates with an excessive proinflammatory immune response and profound lymphopenia. Inflammatory responses according to disease severity were explored by plasma cytokine measurements and proteomics analysis in 147 COVID-19 patients. Furthermore, peripheral blood mononuclear cell cytokine production assays and whole blood flow cytometry were performed. Results confirm a hyperinflammatory innate immune state, while highlighting hepatocyte growth factor and stem cell factor as potential biomarkers for disease severity. Clustering analysis revealed no specific inflammatory endotypes in COVID-19 patients. Functional assays revealed abrogated adaptive cytokine production (interferon-γ, interleukin-17, and interleukin-22) and prominent T-cell exhaustion in critically ill patients, whereas innate immune responses were intact or hyperresponsive. Collectively, this extensive analysis provides a comprehensive insight into the pathobiology of severe to critical COVID-19 and highlights potential biomarkers of disease severity.

Cytokine Profiles Before and After Immune Modulation in Hospitalized Patients with COVID-19.

We describe the cytokine profiles of a large cohort of hospitalized patients with moderate to critical COVID-19, focusing on IL-6, sIL2R, and IL-10 levels before and after receiving immune modulating therapies, namely, tocilizumab and glucocorticoids. We also discuss the possible roles of sIL2R and IL-10 as markers of ongoing immune dysregulation after IL-6 inhibition. We performed a retrospective chart review of adult patients admitted to a tertiary care center with moderate to critical SARS-CoV-2 infection. Disease severity was based on maximum oxygen requirement during hospital stay to maintain SpO2 > 93% (moderate, 0-3 L NC; severe, 4-6 L NC or non-rebreather; critical, HFNC, NIPPV, or MV). All patients were treated using the institution's treatment algorithm, which included consideration of tocilizumab for severe and critical disease. The most common cytokine elevations among all patients included IL-6, sIL2R, IFN-γ, and IL-10; patients who received tocilizumab had higher incidence of IL-6 and sIL2R elevations. Pre-tocilizumab IL-6 levels increased with disease severity (p = .0151). Both IL-6 and sIL2R levels significantly increased after administration of tocilizumab in all severity groups; IL-10 levels decreased in severe (p = .0203), but not moderate or critical, patients after they received tocilizumab. Cluster analysis revealed association between higher admission IL-6, sIL2R, and CRP levels and disease severity. Mean IL-6, sIL2R, and D-dimer were associated with mortality, and tocilizumab-treated patients with elevated IL-6, IL-10, and D-dimer were more likely to also receive glucocorticoids. Accessible clinical cytokine panels may be useful for monitoring response to treatment in COVID-19. The increase in sIL2R post-tocilizumab, despite administration of glucocorticoids, may indicate the need for combination therapy in order to modulate more than one hyperinflammatory pathway in COVID-19. We also discuss the role of cytokines as potential biomarkers for use of adjunct glucocorticoid therapy.

Circulating Levels of Interleukin-6 and Interleukin-10, But Not Tumor Necrosis Factor-Alpha, as Potential Biomarkers of Severity and Mortality for COVID-19: Systematic Review with Meta-analysis.

PURPOSE: Cytokine storm, an uncontrolled overproduction of inflammatory cytokines contributing to an aberrant systemic inflammatory response, is a major pathological feature of acute respiratory distress syndromes being severe manifestations of COVID-19, thus highlighting its potential as a biomarker and therapeutic target for COVID-19. We aimed to determine associations of circulating levels of inflammatory cytokines with severity and mortality of COVID-19 by systematic review and meta-analysis. METHODS: A comprehensive literature search in electronic databases consisting of PubMed, Scopus, and Cochrane Library and in a hand searching of reference lists from inception to July 31, 2020, was performed using the following search terms: COVID-19, interleukin (IL)-6, IL-10, and tumor necrosis factor-alpha (TNF-α). Mean difference (MD) from individual studies was pooled using a random-effects model. Quality assessment, publication bias, meta-regression, subgroup, and sensitivity analyses were performed. RESULTS: A total of 6212 COVID-19 patients from 24 eligible studies were included. Compared with non-severe COVID-19 patients, systemic levels of IL-6 and IL-10, but not TNF-α, were significantly elevated in severe COVID-19 patients (MD = 18.63, 95% CI: 10.91, 26.35, P < 0.00001; MD = 2.61, 95% CI: 2.00, 2.32, P < 0.00001; respectively). For COVID-19 mortality, circulating levels of IL-6, IL-10, and TNF-α were found to be significantly increased in non-survivors when compared with survivors (MD = 57.82, 95% CI: 10.04, 105.59, P = 0.02; MD = 4.94, 95% CI: 3.89, 6.00, P < 0.00001; MD = 5.60, 95% CI: 4.03, 7.17, P < 0.00001; respectively). CONCLUSION: Circulating levels of IL-6 and IL-10 might have great potential as biomarkers for the disease severity and mortality in COVID-19 patients.

Cytokine storm syndrome in coronavirus disease 2019: A narrative review.

Cytokine storm syndrome (CSS) is a critical clinical condition induced by a cascade of cytokine activation, characterized by overwhelming systemic inflammation, hyperferritinaemia, haemodynamic instability and multiple organ failure (MOF). At the end of 2019, the disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China, and rapidly developed into a global pandemic. More and more evidence shows that there is a dramatic increase of inflammatory cytokines in patients with COVID-19, suggesting the existence of cytokine storm in some critical illness patients. Here, we summarize the pathogenesis, clinical manifestation of CSS, and highlight the current understanding about the recognition and potential therapeutic options of CSS in COVID-19.

Evaluation of the relationship between macrophage migration inhibitory factor level and clinical course in patients with COVID-19 pneumonia.

The COVID-19 pandemic, which has ravaged our world for more than a year, still shapes our agenda with a scale of intensity that fluctuates over time. In our study, we aimed to determine the correlation between serum migration inhibitory factor (MIF) level and disease severity in COVID-19 with different prognoses. Between 15 October 2020 and 20 January 2021, 110 patients over the age of 18 who were diagnosed with COVID-19 and 40 volunteer healthcare personnel were included in our study. MIF levels were measured by enzyme-linked immunosorbent assay. In the comparison of serum MIF values in the patient and control group, it was observed that the MIF level was significantly higher in patients with both moderate and severe COVID-19 levels compared to the control group (p = 0.001, 0.001). In the comparison of serum MIF values of moderate to severe COVID-19 patients, it was observed that MIF level was higher in severe patients (p = 0.001). In the receiver operating characteristic curve analysis performed to differentiate between severe and moderate COVID-19 patients with MIF levels, the area under the curve was observed as 0.78. When the cutoff value of the MIF level was taken as 4.455 ng/ml, the sensitivity was 83% and the specificity was 62%. Failure to adequately balance the pro-inflammatory cytokines synthesized in COVID-19 with anti-inflammatory effect is the most important reason for the aggravation of the disease course. Playing a role in pro-inflammatory cytokine synthesis, MIF can provide important information about the disease prognosis in the early period.