The central role of natural killer cells in mediating acute myocarditis after mRNA COVID-19 vaccination

BACKGROUND

Vaccine-related acute myocarditis is recognized as a rare and specific vaccine complication following mRNA-based COVID-19 vaccinations. The precise mechanisms remain unclear. We hypothesized that natural killer (NK) cells play a central role in its pathogenesis.

METHODS

Samples from 60 adolescents with vaccine-related myocarditis were analyzed, including pro-inflammatory cytokines, cardiac troponin T, genotyping, and immunophenotyping of the corresponding activation subsets of NK cells, monocytes, and T cells. Results were compared with samples from 10 vaccinated individuals without myocarditis and 10 healthy controls.

FINDINGS

Phenotypically, high levels of serum cytokines pivotal for NK cells, including interleukin-1β (IL-1β), interferon α2 (IFN-α2), IL-12, and IFN-γ, were observed in post-vaccination patients with myocarditis, who also had high percentage of CD57+ NK cells in blood, which in turn correlated positively with elevated levels of cardiac troponin T. Abundance of the CD57+ NK subset was particularly prominent in males and in those after the second dose of vaccination. Genotypically, killer cell immunoglobulin-like receptor (KIR) KIR2DL5B(-)/KIR2DS3(+)/KIR2DS5(-)/KIR2DS4del(+) was a risk haplotype, in addition to single-nucleotide polymorphisms related to the NK cell-specific expression quantitative trait loci DNAM-1 and FuT11, which also correlated with cardiac troponin T levels in post-vaccination patients with myocarditis.

CONCLUSION

Collectively, these data suggest that NK cell activation by mRNA COVID-19 vaccine contributed to the pathogenesis of acute myocarditis in genetically and epidemiologically vulnerable subjects.

FUNDING

This work was funded by the Hong Kong Collaborative Research Fund (CRF) 2020/21 and the CRF Coronavirus and Novel Infectious Diseases Research Exercises (reference no. C7149-20G).

SARS-CoV-2 infection of endothelial cells, dependent on flow-induced ACE2 expression, drives hypercytokinemia in a vascularized microphysiological system

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for COVID-19, has caused nearly 7 million deaths worldwide. Severe cases are marked by an aggressive inflammatory response known as hypercytokinemia, contributing to endothelial damage. Although vaccination has reduced hospitalizations, hypercytokinemia persists in breakthrough infections, emphasizing the need for disease models mimicking this response. Using a 3D microphysiological system (MPS), we explored the vascular role in SARS-CoV-2-induced hypercytokinemia.

Methods

The vascularized micro-organ (VMO) MPS, consisting of human-derived primary endothelial cells (ECs) and stromal cells within an extracellular matrix, was used to model SARS-CoV-2 infection. A non-replicative pseudotyped virus fused to GFP was employed, allowing visualization of viral entry into human ECs under physiologic flow conditions. Expression of ACE2, TMPRSS2, and AGTR1 was analyzed, and the impact of viral infection on ACE2 expression, vascular inflammation, and vascular morphology was assessed.

Results

The VMO platform facilitated the study of COVID-19 vasculature infection, revealing that ACE2 expression increased significantly in direct response to shear stress, thereby enhancing susceptibility to infection by pseudotyped SARS-CoV-2. Infected ECs secreted pro-inflammatory cytokines, including IL-6 along with coagulation factors. Cytokines released by infected cells were able to activate downstream, non-infected EC, providing an amplification mechanism for inflammation and coagulopathy.

Discussion

Our findings highlight the crucial role of vasculature in COVID-19 pathogenesis, emphasizing the significance of flow-induced ACE2 expression and subsequent inflammatory responses. The VMO provides a valuable tool for studying SARS-CoV-2 infection dynamics and evaluating potential therapeutics.

Biparatopic Nanobody-Based Immunosorbent for the Highly Selective Elimination of Tumor Necrosis Factor-α

Removing the overexpressed TNF-α by hemoperfusion positively affects clinical treatments for diseases such as autoimmune disease and sepsis. However, clearance ratios of adsorbents targeting TNF-α were limited by the extremely low concentration of TNF-α (mostly <1000 ng/L in sepsis) and hydrophobic interactions. In this work, biparatopic nanobodies (NbC21) with a high affinity of 19.9 pM, which bind to two distinct sites of TNF-α, were constructed as high-affinity ligands for the immunosorbent. The theoretical maximum adsorption capacity estimated from the Langmuir isotherm was up to 18.22 mg/g gel. The prepared immunosorbent (NbC21-sorbent) had an outstanding TNF-α clearance ratio of approximately 96% during the dynamic adsorption test, with a sorbent-to-serum ratio of 1:1000. Additionally, it demonstrated favorable hemocompatibility and a prolonged storage capability. The results indicated that the biparatopic nanobody immunosorbent exhibited significant potential for clinical applications as it met the stringent criteria for both efficacy and safety.

Retrospective observational study of changes in serum cytokines and adiponectin with continuous plasma exchange with dialysis therapy for severe COVID-19

INTRODUCTION

Coronavirus disease 2019 (COVID-19) is associated with a marked increase in the inflammatory cytokines, IL-6 and IL-18. Blood purification therapy aimed at controlling cytokines is one treatment option; however, evidence of its effectiveness is needed. Plasma exchange with dialysis (PED) is a blood purification method involving selective plasma exchange with dialysate flowing through the outer hollow fiber of the plasma separator. In this retrospective study, we investigated the efficacy of continuous PED (cPED) over 48 h in five patients with severe COVID-19.

METHODS

We assessed changes in IL-6 and IL-18, as well as adiponectin (APN).

RESULTS

There were no significant differences in changes in IL-6 and IL-18, but there was a marked improvement in cases with abnormally high IL-6 and IL-18 levels at baseline. APN, which inhibits inflammatory cytokines, was significantly elevated post-cPED.

CONCLUSION

Our results suggest that cPED therapy is an effective treatment for COVID-19.

Serum levels of type I interferon (IFN-I) is associated with the severity of COVID-19

Introduction. Caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, coronavirus disease 2019 (COVID-19) has threatened global public health. Immune damage mechanisms are essential guidelines for clinical treatment and immune prevention.Hypothesis. The dysregulated type I interferon (IFN-I) responses, lymphocytopenia and hypercytokinemia during SARS-CoV-2 infection have been reported. However, whether there is a correlation between levels of IFN-I and the severity of COVID-19 has not been reported yet.Aim. To investigate the source of IFN-I and detect the exact roles of them in the pathogenesis of COVID-19.Methodology. Here ELISA was used to detect serum IFN-I (IFN-α and IFN-β) for 137 cases with laboratory-confirmed COVID-19 admitted into one hospital in Wuhan from December 2019 to March 2020, and the relationships between IFN-α/β concentrations and patients' clinical parameters were conducted by statistical analysis.Results. Both IFN-α and IFN-β concentrations dramatically increased in COVID-19 patients, especially in old patients (>80 years) and severe cases. Statistical analysis demonstrated that serum IFN-α/β concentrations were negatively correlated with the counts of total CD3+T, CD4⁺ and CD8⁺T cells, especially in critically ill cases. Moreover, serum IFN-α levels were positively correlated to IL-6 and TNF-α. Finally, immunofluorescent double staining showed that IFN-α and IFN-β are major secretions from macrophages and dendritic cells (DCs) in lymph nodes from COVID-19 autopsies.Conclusion. These results demonstrate that macrophages and DCs are the main origination of IFN-I, and serum levels of IFN-I are positively associated with lymphopenia and cytokine storm, suggesting that IFN-α/β deteriorated the severity of COVID-19. Anti-interferon or IFN-I signalling block drugs are needed to treat ICU patients.

Comparisons of lymphocytes profiles and inflammatory cytokines levels in blood of patients with differed severity of infection by human adenovirus type 7

BACKGROUND

Human adenovirus (HAdV) infection outbreak causes community-acquired pneumonia. Cellular immune dysfunction and hypercytokinemia play important roles in the pathogenesis of adenovirus respiratory infection. Some soluble factors in peripheral blood can assist in judging the virus-induced disease severity. The expression levels of inflammatory cytokines differ among patients with different disease severity. However, whether and how HAdV-7 infection influences the composition of blood immune cells and serum cytokine levels in patients at different disease stages, as well as the diagnosis values of these parameters, have rarely been intensively studied. We aimed to investigate lymphocytes profiles and cytokines levels in blood of patients at different disease stages upon human adenovirus type 7 (HAdV-7) infections, and explored the diagnosis values of the investigated parameters.

METHODS

Patients from two outbreaks of HAdV-7 in military of China were categorized into upper respiratory infection (URI) group, common pneumonia (CP) group and severe pneumonia (SP) group according to disease severity. Peripheral blood samples were subjected to routine laboratory tests, while flow cytometry and ELISA were used to measure the lymphocyte subsets and cytokines in blood, respectively. The receiver operating characteristic (ROC) curves were performed to examine the diagnostic of these blood parameters.

RESULTS

Signs of imbalanced lymphocytes composition and hypercytokinemia were observed in HAdV-7-infected patients. The percentages of CD3⁺ T cells and NK cells were significantly decreased along with the aggravation of the disease, particularly for NK cells and CD4⁺ T cells. The neutrophil to lymphocyte ratio (NLR) increased significantly in patients with more severe disease. In addition, the levels of serum CXCL10, IL-2 and TNF-α were positively correlated with disease severity, while reduced levels of IFN-γ and IL-10 were found in SP patients. Furthermore, analysis of ROC showed that multiple parameters including the percentage of blood CD3⁺ cells and serum CXCL10 level could predict the progression of HAdV-7 infection.

CONCLUSION

Imbalance of immune state with hypercytokinemia occurred during HAdV-7 infection. The percentages of blood immune cells such as CD3⁺ T cells and the levels of serum cytokines such as CXCL10 showed potential diagnosis values in HAdV-7 infection.

Inducible generalized activation of hSTING-N154S expression in mice leads to lethal hypercytokinemia: a model for "cytokine storm"

Excessive levels of circulating proinflammatory mediators, known as "hypercytokinemia," that are generated by overwhelming immune system activation can lead to death due to critical organ failure and thrombotic events. Hypercytokinemia has been frequently associated with a variety of infectious and autoimmune diseases, with severe acute respiratory syndrome coronavirus 2 infection currently being the commonest cause, of what has been termed the cytokine storm. Among its various functions within the host, STING (stimulator of interferon genes) is critical in the defense against certain viruses and other pathogens. STING activation, particularly within cells of the innate immune system, triggers potent type I interferon and proinflammatory cytokine production. We thus hypothesized that generalized expression of a constitutively active STING mutant in mice would lead to hypercytokinemia. To test this, a Cre-loxP-based system was used to cause the inducible expression of a constitutively active hSTING mutant (hSTING-N154S) in any tissue or cell type. Herein, we employed a tamoxifen-inducible ubiquitin C-CreERT2 transgenic to obtain generalized expression of the hSTING-N154S protein, thereby triggering the production of IFN-β and multiple proinflammatory cytokines. This required euthanizing the mice within 3 to 4 d after tamoxifen administration. This preclinical model will allow for the rapid identification of compounds aimed at either preventing or ameliorating the lethal effects of hypercytokinemia.

Fatal Fulminant Cerebral Edema in Six Children With SARS-CoV-2 Omicron BA.2 Infection in Taiwan

Acute fulminant cerebral edema in children following SARS-CoV-2 infection has been rarely reported. Such patients frequently demonstrate rapid progression and are usually fatal. In this retrospective study, we describe the detailed clinical, laboratory, and neuroimaging features of six fatal cases in Taiwan. All patients had shock initially, five showed rapid progression to multiorgan failure and disseminated intravascular coagulation, and three developed acute respiratory distress syndromes. The inflammatory biomarkers in the first 3 days, including interleukin 6, ferritin, lactate dehydrogenase, and D-dimer, showed significant elevation in all cases. The hyperinflammatory response may play a role in the pathophysiology.

RNF213-associated urticarial lesions with hypercytokinemia

BACKGROUND

Urticarial lesions are observed in both cutaneous and systemic disorders. Familial forms of urticarial syndromes are rare and can be encountered in systemic autoinflammatory diseases.

OBJECTIVE

We sought to investigate a large family with dominantly inherited chronic urticarial lesions associated with hypercytokinemia.

METHODS

We performed a genetic linkage analysis in 14 patients from a 5-generation family, as well as whole-exome sequencing, cytokine profiling, and transcriptomic analyses on samples from 2 patients. The identified candidate protein was studied after in vitro expression of the corresponding normal and mutated recombinant proteins. An unsupervised proteomic approach was used to unveil the associated protein network.

RESULTS

The disease phenotype of the most affected family members is characterized by chronic urticarial flares associated with extremely high plasma levels of proinflammatory (IL-1β, IL-6, and TNF-α) and anti-inflammatory (IL-10 and IL-1 receptor antagonist [IL-1RA]) cytokines, with no secondary organ dysfunction, no susceptibility to infections, no fever, and normal C-reactive protein levels. Monocyte transcriptomic analyses identified an immunotolerant profile in the most affected patient. The affected family members carried a loss-of-function mutation in RNF213 that encodes mysterin, a protein with a poorly known physiologic role. We identified the deubiquitinase CYLD, a major regulator of inflammation, as an RNF213 partner and showed that CYLD expression is inhibited by wild-type but not mutant RNF213.

CONCLUSION

We identified a new entity characterized by chronic urticarial lesions associated with a clinically blunted hypercytokinemia. This disease, which is due to loss of function of RNF213, reveals mysterin's key role in the complex molecular network of innate immunity.

Cleavage-Responsive Biofactory T Cells Suppress Infectious Diseases-Associated Hypercytokinemia

Severe infectious diseases, such as coronavirus disease 2019 (COVID-19), can induce hypercytokinemia and multiple organ failure. In spite of the growing demand for peptide therapeutics against infectious diseases, current small molecule-based strategies still require frequent administration due to limited half-life and enzymatic digestion in blood. To overcome this challenge, a strategy to continuously express multi-level therapeutic peptide drugs on the surface of immune cells, is established. Here, chimeric T cells stably expressing therapeutic peptides are presented for treatment of severe infectious diseases. Using lentiviral system, T cells are engineered to express multi-level therapeutic peptides with matrix metallopeptidases- (MMP-) and tumor necrosis factor alpha converting enzyme- (TACE-) responsive cleavage sites on the surface. The enzymatic cleavage releases γ-carboxyglutamic acid of protein C (PC-Gla) domain and thrombin receptor agonist peptide (TRAP), which activate endothelial protein C receptor (EPCR) and protease-activated receptor-1 (PAR-1), respectively. These chimeric T cells prevent vascular damage in tissue-engineered blood vessel and suppress hypercytokinemia and lung tissue damages in vivo, demonstrating promise for use of engineered T cells against sepsis and other infectious-related diseases.

An autopsy case of fulminant myocarditis after severe acute respiratory syndrome coronavirus 2 vaccine inoculation

A 61‐year‐old woman without significant medical history developed fever 3 days after severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) vaccination and went into shock the next day. She was negative for SARS‐CoV‐2 mRNA in real‐time polymerase chain reaction (PCR). Finally, she died 10 days after vaccination. At autopsy, the heart showed moderate dilatation of both ventricles, and the myocardium showed an uneven color change and decreased elasticity. Histologically, severe myocarditis with extensive myocytolysis was observed. The myocarditis showed severe inflammatory cell infiltration with T‐lymphocyte and macrophage predominance, and in addition to the inflammatory cells described above, vast nuclear dust accompanying neutrophilic infiltration was observed. In the bone marrow and lymph nodes, hemophagocytosis was observed. In postmortem examination, nucleic acids of any cardiotropic viruses including SARS‐CoV‐2 were not detected using multivirus real‐time PCR system. We discussed the relationship between the possible immune reaction after vaccination and the myocarditis observed in this case from immunopathological viewpoints. This mRNA vaccine is the first applied nucleic acid vaccine for humans, and its mechanism of efficacy and immune acquisition remain unclear. We hope the accumulation of more detailed analyses of the similar cases to reveal the mechanism of this kind of adverse reaction.

Antiplatelet Activity of Riamilovir under Conditions of Lipopolysaccharide Intoxication

We studied the effect of antiviral agent riamilovir on ADP-induced platelet aggregation in the absence and presence of LPS. Unlike acetylsalicylic acid (reference drug), riamilovir did not exhibit antiplatelet effect in vitro. However, it markedly suppressed platelet reactivity in LPS-treated blood samples and was 2.2-fold superior to acetylsalicylic acid in terms of IC₅₀ value. In in vivo experiments, riamilovir under conditions of hypercytokinemia blocked platelet aggregation in rats by 64%.

Cytokine Hemoadsorption as Rescue Therapy for Critically Ill Patients With SARS-CoV-2 Pneumonia With Severe Respiratory Failure and Hypercytokinemia

Introduction: A dysregulated inflammatory response, known as “cytokine storm”, plays an important role in the pathophysiology of coronavirus 2019 disease (COVID-19). Identifying patients with a dysregulated inflammatory response and at high risk for severe respiratory failure, organ dysfunction, and death is clinically relevant, as they could benefit from the specific therapies, such as cytokine removal by hemoadsorption. This study aimed to evaluate cytokine hemoadsorption as rescue therapy in critically ill patients with SARS-CoV-2 pneumonia, severe respiratory failure refractory to prone positioning, and hypercytokinemia.

Methods: In this single center, observational and retrospective study, critically ill patients with SARS-CoV-2 pneumonia, severe acute respiratory failure, and hypercytokinemia were analyzed. All the patients underwent cytokine hemoadsorption using CytoSorb^® (Cytosorbents Europe, Berlin, Germany). The indication for treatment was acute respiratory failure, inadequate clinical response to the prone position, and hypercytokinemia.

Results: Among a total of 343 patients who were admitted to the intensive care unit (ICU) due to SARS-CoV-2 infection between March 3, 2020 and June 22, 2020, six patients received rescue therapy with cytokine hemoadsorption. All the patients needed invasive mechanical ventilation and prone positioning. A significant difference was found in the pre- and post-treatment D-dimer (17,868 mcg/ml [4,196–45,287] vs. 4,488 mcg/ml [3,166–17,076], p = 0.046), C-reactive protein (12.9 mg/dl [10.6] vs. 3.5 mg/dl [2.8], p = 0.028), ferritin (1,539 mcg/L [764–27,414] vs. 1,197 ng/ml [524–3,857], p = 0.04) and interleukin-6 (17,367 pg/ml [4,539–22,532] vs. 2,403 pg/ml [917–3,724], p = 0.043) levels. No significant differences in the pre- and post-treatment interleukin-10 levels (22.3 pg/ml [19.2–191] vs. 5.6 pg/ml [5.2–36.6], p = 0.068) were observed. Improvements in oxygenation (prehemoadsorption PaO₂/FIO₂ ratio 103 [18.4] vs. posthemoadsorption PaO₂/FIO₂ ratio 222 [20.9], p = 0.029) and in the organ dysfunction (prehemoadsorption SOFA score 9 [4.75] vs. posthemoadsorption SOFA score 7.7 [5.4], p = 0.046) were observed. ICU and in-hospital mortality was 33.7%.

Conclusions: In this case series, critically ill patients with COVID-19 with severe acute respiratory failure refractory to prone positioning and hypercytokinemia who received adjuvant treatment with cytokine hemoadsorption showed a significant reduction in IL-6 plasma levels and other inflammatory biomarkers. Improvements in oxygenation and SOFA score were also observed.

Virus-triggered secondary hemophagocytic lymphohistiocytosis

Primary (familial/hereditary) and secondary (non-familial/hereditary) hemophagocytic lymphohistiocytosis (HLH) are hyperinflammatory and hypercytokinemic syndromes. Secondary HLH includes infection- (eg viral/bacterial/fungal/parasitic) and non-infection- (eg collagen disease or malignancy) related diseases. Viral HLH is the major type among all age groups. Secondary viral HLH and primary HLH must be differentiated carefully because primary HLH can be associated with viral infection(s), and the outcome is dismal without a timely diagnosis and hematopoietic stem cell transplantation (HSCT). Epstein-Barr virus (EBV)-related HLH (EBV-HLH) is the most common type of viral HLH in childhood. For non-EBV-HLH, appropriate treatment of viral infection, followed by immunomodulatory agent(s) such as corticosteroids, intravenous immunoglobulin or cyclosporine A, is usually successful; however, recent SARS-CoV-2-related HLH may become life-threatening. EBV-HLH may occur heterogeneously associated with the primary infection, with chronic active EBV infection or with underlying primary HLH. Although immunomodulatory agent(s) are effective in the majority of EBV-HLH cases, management differs from that of non-EBV-HLH because severe and refractory cases may require etoposide-containing HLH-1994/2004 regimens or other experimental agents. The novel agent, emapalumab (an anti-IFN-γ monoclonal antibody) can be used to treat EBV-HLH cases to avoid the risk of secondary malignancy due to etoposide. Finally, HSCT is required for refractory EBV-HLH cases and can also be curative in some other cases.

Potential Immunomodulatory Properties of Biologically Active Components of Spices Against SARS-CoV-2 and Pan β-Coronaviruses

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced COVID-19 has emerged as a defining global health crisis in current times. Data from the World Health Organization shows demographic variations in COVID-19 severity and lethality. Diet may play a significant role in providing beneficial host cell factors contributing to immunity against deadly SARS-CoV-2 pathogenesis. Spices are essential components of the diet that possess anti-inflammatory, antioxidant, and antiviral properties. Hyperinflammation, an aberrant systemic inflammation associated with pneumonia, acute respiratory failure, and multiorgan dysfunction, is a major clinical outcome in COVID-19. Knowing the beneficial properties of spices, we hypothesize that spice-derived bioactive components can modulate host immune responses to provide protective immunity in COVID-19. This study emphasizes that biologically active components of spices might alleviate the sustained pro-inflammatory condition by inhibiting the activity of tumor necrosis factor-alpha (TNF-α), interleukins (IL6, IL8), and chemokine (CCL2) known to be elevated in COVID-19. Spices may potentially prevent the tissue damage induced by oxidative stress and pro-inflammatory mediators during SARS-CoV-2 infection. The current study also highlights the effects of spices on the antioxidant pathways mediated by Nrf2 (nuclear factor erythroid 2-related factor 2) and Hmox1 (heme oxygenase 1) to restore oxidative homeostasis and protect from aberrant tissue damage. Taken together, the anti-inflammatory and antioxidant activities of bioactive components of spices may hold a promise to target the cellular pathways for developing antivirals against SARS-CoV-2 and pan β-coronaviruses.

The role of influenza A virus-induced hypercytokinemia

Influenza viruses are one of the leading causes of respiratory tract infections in humans and their newly emerging and re-emerging virus strains are responsible for seasonal epidemics and occasional pandemics, leading to a serious threat to global public health systems. The poor clinical outcome and pathogenesis during influenza virus infection in humans and animal models are often associated with elevated proinflammatory cytokines and chemokines production, which is also known as hypercytokinemia or "cytokine storm", that precedes acute respiratory distress syndrome (ARDS) and often leads to death. Although we still do not fully understand the complex nature of cytokine storms, the use of immunomodulatory drugs is a promising approach for treating hypercytokinemia induced by an acute viral infection, including highly pathogenic avian influenza virus infection and Coronavirus Disease 2019 (COVID-19). This review aims to discuss the immune responses and cytokine storm pathology induced by influenza virus infection and also summarize alternative experimental strategies for treating hypercytokinemia caused by influenza virus.

PMX-DHP Therapy for Dyspnea and Deoxygenation in Severe COVID-19 Pneumonia: A Case Series

Hypercytokinemia induced by coronavirus disease-19 (COVID-19) is associated with severe pulmonary involvement, which may lead to respiratory failure. These conditions play an important role in the worsening of clinical symptoms in patients with severe COVID-19. There is no established treatment for hypercytokinemia. We report on two patients whose clinical symptoms improved after direct hemoperfusion using polymyxin B-immobilized fiber column (PMX-DHP), following the administration of the anti-inflammatory agent tocilizumab. Case A was a 70-year-old man diagnosed with COVID-19 pneumonia. Despite treatment with ciclesonide and favipiravir, supplemental oxygen was administered due to the worsening of dyspnea with tachypnea. Although tocilizumab was started on day 6, the patient deteriorated into deoxygenation, presenting with the PaO₂/F_IO₂ (P/F) ratio of 92. On days 8 and 10, the patient received PMX-DHP therapy. On day 11, his dyspnea improved. On day 13, his P/F ratio began to improve, and oxygen therapy was discontinued on day 18. The patient recovered without requiring mechanical ventilation. Case B was a 70-year-old man diagnosed with COVID-19 pneumonia and treated with favipiravir, starting on day 0. Despite starting ciclesonide inhalation and tocilizumab on day 2, his P/F ratio was 53. On day 5, he received PMX-DHP therapy. On day 6, his dyspnea improved, as did his P/F ratio, reaching 81 on day 8. Finally, his clinical symptoms resolved, and he was discharged from the intensive care unit without requiring mechanical ventilation. These cases indicate that PMX-DHP therapy might be a suitable treatment option for dyspnea and deoxygenation in COVID-19 pneumonia, especially in cases where an anti-inflammatory agent, such as tocilizumab, has failed to achieve the desired effect.

A woman with adult-onset Still's disease and acute intestinal pseudo-obstruction

Adult-onset Still's disease may cause intestinal pseudo-obstruction via a cytokine storm. Early diagnosis and treatment are the key for patient survival before the development of serious complications such as macrophage activation syndrome.

The Artificial-Liver Blood-Purification System Can Effectively Improve Hypercytokinemia for COVID-19

Since the December 2019 outbreak of coronavirus disease 2019 (COVID-19) in Wuhan, the infection has spread locally and globally resulting in a pandemic. As the numbers of confirmed diagnoses and deaths continue to rise, COVID-19 has become the focus of international public health. COVID-19 is highly contagious, and there is no effective treatment yet. New treatment strategies are urgently needed to improve the treatment success rate of severe and critically ill patients. Increasing evidence has shown that a cytokine storm plays an important role in the progression of COVID-19. The artificial-liver blood-purification system (ALS) is expected to improve the outcome of the cytokine storm. In the present study, the levels of cytokines were detected in 12 COVID-19 patients pre- and post-ALS with promising results. The present study shows promising evidence that ALS can block the cytokine storm, rapidly remove the inflammatory mediators, and hopefully, suppress the progression of the disease, thereby providing a new strategy for the clinical treatment of COVID-19.

Cytokine Storm May Not Be the Chief Culprit for the Deterioration of COVID-19

COVID-19 is spreading and ravaging all over the world, and the number of deaths is increasing day by day without downward trend. However, there is limited knowledge of pathogenesis on the deterioration of COVID-19 at present. In this study we aim to determine whether cytokine storm is really the chief culprit for the deterioration of COVID-19. The confirmed COVID-19 patients were divided into moderate group (n = 89), severe group (n = 37), and critical group (n = 41). Demographic data were collected and recorded on admission to ICU. Clinical data were obtained when moderate, severe, or critical COVID-19 was diagnosed, and then compared between groups. The proportion of enrolled COVID-19 patients was slightly higher among males (52.5%) than females (47.5%), with an average age of 64.87 years. The number of patients without comorbidities exceed one third (36.1%), and patients with 1, 2, 3, 4 kinds of comorbidities accounted for 23.0%, 23.0%, 13.1%, and 4.9%, respectively. IL-6, IL-10, TNF, and IFN-γ, including oxygenation index, sequential organ failure assessment score, white blood cell count, lymphocyte count, lymphocyte percentage, platelet, C-reaction protein, lactate dehydrogenase, creatine kinase isoenzyme, albumin, D-Dimer, and fibrinogen showed significant difference between groups. Some, but not all, cytokines and chemokines were involved in the deterioration of COVID-19, and thus cytokine storm maybe just the tip of the iceberg and should be used with caution to explain pathogenesis on the deterioration of COVID-19, which might be complex and related to inflammation, immunity, blood coagulation, and multiple organ functions. Future studies should focus on identification of specific signaling pathways and mechanisms after severe acute respiratory syndrome coronavirus 2 infections (IRB number: IRB-AF/SC-04/01.0).

Rapidly Exacerbating Autoimmune Hemolytic Anemia Together With Marked Cytokine Storm Triggered by Pneumonia Infection: A Case Report

Background: Autoimmune hemolytic anemia (AIHA) is caused by hemolysis induced by the reaction of autoantibodies with red blood cells. AIHA is usually classified as either warm antibody or cold antibody-mediated AIHA. In addition, AIHA caused by infection is classified as secondary AIHA. It is well-known that alteration of various cytokine levels is closely associated with a variety of disorders such as infectious diseases. In addition, it is known that IL-10/ IL-12 imbalance is an indicator of Th2-dominat conditions and a progressive marker of AIHA. Case presentation: A 82-year-old Japanese man was brought to the emergency room with pneumonia and heart failure. After admission, we started antibiotics therapy. Next day, he had symptoms of jaundice and his total bilirubin level was elevated. Five days after admission, his inflammation markers were further elevated and he had hemolytic anemia. We finally diagnosed him as severe warm-type AIHA associated with pneumoniae infection. Seven days after admission, his severe leucocytosis was further aggravated, and then he suddenly had cardiac arrest and respiratory failure, and finally died of multiple organ failure. Unfortunately, we failed to rescue him from severe AIHA induced by pneumonia infection. Conclusions: Herein, we report a subject with pneumonia-triggered warm-type AIHA together with marked cytokine storm. IL-18 levels were markedly elevated without elevation of IL-12 levels. In addition, IL-10/IL-12 imbalance was observed. These data suggest that once marked cytokine storm is induced, infection-induced AIHA is exacerbated very rapidly.

Hypercytokinemia and Pathogen-Host Interaction in COVID-19

Severe acute respiratory syndrome (SARS) coronavirus (CoV)-2 (SARS-CoV-2) is a novel coronavirus identified as the cause of coronavirus disease-2019 (COVID-19) that began in Wuhan, China in late 2019 and spread now in 210 countries and territories around the world. Many people are asymptomatic or with mild symptoms. However, in some cases (usually the elderly and those with comorbidities) the disease may progress to pneumonia, acute respiratory distress syndrome and multi-organ dysfunction that can lead to death. Such wide interindividual differences in response to SARS-CoV-2 infection may relate to several pathogen- and host-related factors. These include the different levels of the ubiquitously present human angiotensin I converting enzyme 2 (ACE2) receptors gene expression and its variant alleles, the different binding affinities of ACE2 to the virus spike (S) protein given its L- and S-subtypes and the subsequent extent of innate immunity-related hypercytokinemia. The extensive synthesis of cytokines and chemokines in coronavirus diseases was suggested as a major factor in exacerbating lung damage and other fatal complications. The polymorphisms in genes coding for pro-inflammatory cytokines and chemokines have been associated with mediating the response and susceptibility to a wide range of infections and their severe outcomes. Understanding the nature of pathogen-host interaction in COVID-19 symptomatology together with the role of hypercytokinemia in disease severity may permit developing new avenues of approach for prevention and treatment and can delineate public health measures to control the spread of the disease.

Posttransplant Hemophagocytic Lymphohistiocytosis Driven by Myeloid Cytokines and Vicious Cycles of T-Cell and Macrophage Activation in Humanized Mice

Hemophagocytic lymphohistiocytosis (HLH) has recently been increasingly reported as an important complication after stem cell transplantation, in line with the increase in the number of HLA-mismatched transplantation. Although previous clinical studies have shown an elevation of inflammatory cytokines in patients with HLH after hematopoietic stem cell transplantation, as well as those after viral infection or autoimmune disease, the disease pathogenesis remains poorly understood. Here we explored this issue in humanized mice with functional human lymphohematopoietic systems, which were constructed by transplantation of human CD34⁺ cells alone, or along with human fetal thymus into NOD/SCID/γc^−/− (NSG) or NSG mice carrying human SCF/GM-CSF/IL-3 transgenes (SGM3). In comparison with humanized NSG (huNSG) mice, huSGM3 mice had higher human myeloid reconstitution and aggressive expansion of human CD4⁺ memory T cells, particularly in the absence of human thymus. Although all huNSG mice appeared healthy throughout the observation period of over 20 weeks, huSGM3 mice developed fatal disease characterized by severe human T cell and macrophage infiltrations to systemic organs. HuSGM3 mice also showed severe anemia and thrombocytopenia with hypoplastic bone marrow, but increased reticulocyte counts in blood. In addition, huSGM3 mice showed a significant elevation in human inflammatory cytokines including IL-6, IL-18, IFN-α, and TNF-γ, faithfully reproducing HLH in clinical situations. Our study suggests that posttransplant HLH is triggered by alloresponses (or xenoresponses in our model), driven by myeloid cytokines, and exacerbated by vicious cycles of T-cell and macrophage activation.

Dual Threat of Epstein-Barr Virus: an Autopsy Case Report of HIV-Positive Plasmablastic Lymphoma Complicating EBV-Associated Hemophagocytic Lymphohistiocytosis

Epstein-Barr virus (EBV) reactivation causes serious diseases in immunocompromised hosts, such as acquired immunodeficiency syndrome (AIDS). We report on a case of plasmablastic lymphoma (PBL) with hemophagocytic lymphohistiocytosis (HLH).A-53-year-old Japanese man was diagnosed with PBL and AIDS. In addition to combined antiretroviral therapy, HyperCVAD (cyclophosphamide, doxorubicin, vincristine, prednisone)/high-dose methotrexate + cytarabine was initiated immediately. Partial remission was attained with chemotherapy. However, the patient developed HLH and died despite intensive therapy. Autopsy findings suggested that PBL was controlled, and immunosuppression appeared to cause fatal infection. The patient showed high titers of EBV viral-capsid antigen (VCA)-IgG (1:2560) on PBL diagnosis and high EBV-DNA levels throughout the clinical course. Moreover, EBV-DNA was detected in the fraction of CD8-positive cells, which strongly supports the pathogenesis of EBV-associated HLH.Our report highlights the importance of EBV control in patients with EBV-positive AIDS lymphoma. EBV not only behaves as the etiologic pathogen of PBL but also can be a trigger of HLH, the fatal complication. Careful follow-up of the EBV status should be performed, and if needed, preemptive anti-EBV therapy should also be considered to prevent EBV-associated complications such as HLH.

Current and future developments in the treatment of virus-induced hypercytokinemia

Emerging pathogenic viruses such as Ebola and Middle Eastern Respiratory Syndrome coronavirus (MERS-CoV) can cause acute infections through the evasion of the host's antiviral immune responses and by inducing the upregulation of inflammatory cytokines. This immune dysregulation, termed a cytokine storm or hypercytokinemia, is potentially fatal and is a significant underlying factor in increased mortality of infected patients. The prevalence of global outbreaks in recent years has offered opportunities to study the progression of various viral infections and have provided an improved understanding of hypercytokinemia associated with these diseases. However, despite this increased knowledge and the study of the infections caused by a range of emerging viruses, the therapeutic options still remain limited. This review aims to explore alternative experimental strategies for treating hypercytokinemia induced by the Ebola, avian influenza and Dengue viruses; outlining their modes of action, summarizing their preclinical assessments and potential clinical applications.

Cytokine profile in two siblings with neonatal lupus erythematosus

We studied the cytokine profile of two siblings with neonatal lupus erythematosus (NLE) born to a mother positive for serum anti-Ro and -La antibodies, who did not receive any medication during the two pregnancies. The first sibling was found to have complete atrioventricular block in utero and became severely ill after birth. He fulfilled the diagnostic criteria for hemophagocytic lymphohistiocytosis on day 2. The second sibling did not have any fetal symptoms. He was generally stable after birth, but with typical skin rash. Laboratory data suggested that they both had hypercytokinemia during the neonatal period, requiring corticosteroid treatment. Interleukin (IL)-6, interferon-γ, IL-8 and monocyte chemotactic protein-1 were elevated in both cases, while IL-12, IL-13 and IL-17 were elevated only in the second sibling. Comparison of the cytokine profiles suggests the potential roles of different cytokines in the onset and clinical manifestations of NLE.

Lung abscess caused by Mycoplasma pneumoniae

A 10-year-old boy with West syndrome was referred to hospital because of high fever and cough. Chest X-ray and computed tomography showed consolidation with an abscess in the right upper lobe. Laboratory data indicated cytokine storm. Various antibacterial agents and additional corticosteroid were unable to control the hypercytokinemia, which was suppressed after cyclosporine A was started. The lung abscess remained, however, and right upper lobectomy was performed. Culture from the abscess showed no growth, while polymerase chain reaction assay indicated Mycoplasma pneumoniae DNA. Serum passive agglutinin titer for M. pneumoniae was significantly elevated in the convalescent phase. These findings are strong evidence that the lung abscess was caused by M. pneumoniae infection.

Management of the critically ill child with the sepsis/hemophagocytic lymphohistiocytosis/macrophage activation syndrome overlap syndrome

Hemophagocytic lymphohistiocytosis (HLH) or macrophage activation syndrome (MAS) is a frequently fatal disease, which can result in end-organ damage and death. This condition shares features with sepsis and systemic inflammatory response syndrome. Making a diagnosis of HLH can be challenging since most of the clinical and laboratory features of HLH are quite nonspecific. Timely diagnosis is critical to start therapy before damage by hypercytokinemia becomes irreversible. The treatment for patients with suspected acquired HLH/sepsis/systemic inflammatory response syndrome/multi organ dysfunction syndrome/ MAS overlap syndrome should be guided primarily by the severity of signs and symptoms, age of the patient, and underlying conditions. It is critical that the risks of treatment or non-treatment be weighed according to the clinical presentation of each patient. In this article, the authors discuss the diagnostic similarities between sepsis/HLH/MAS and management of the critically ill child with sepsis/HLH/MAS overlap syndrome.

Influenza virus infection mimicking an acute abdomen in a female adolescent

We report an adolescent with respiratory symptoms admitted for clinical signs of an acute abdomen. The only diagnostic finding was influenza A viral RNA detected in an upper respiratory tract specimen. Influenza should be considered in the differential diagnosis of children with respiratory illness and abdominal pain during influenza season.

Postnatal changes of cytokines in premature infants with or without funisitis

OBJECTIVE

Fetal inflammatory response syndrome (FIRS), which induces hypercytokinemia, is important for the outcomes of premature infants. It is necessary to focus on the fetal inflammatory environments.

METHODS

A total of 37 premature infants (gestational age ≤32 weeks) were divided into three groups: (1) 15 without chorioamnionitis (CAM) and funisitis; C(-)F(-) group, (2) 15 with CAM but without funisitis; C(+)F(-) group and (3) 7 with CAM and funisitis; C(+)F(+) group. Blood interleukin (IL)-1β, IL-6 and IL-8 levels were measured on day 0 (= in umbilical cord blood), 3, 7, 14, 21 and 28.

RESULTS

(1) day 0: Cord blood concentrations of IL-1β, IL-6 and IL-8 were significantly higher in the C(+)F(+) group than in the C(+)F(-) group and C(-)F(-) group. On the other hand, they were comparable between the C(+)F(-) group and C(-)F(-) group. (2) Days 3-28: elevated cytokines levels in the C(+)F(+) group with funisitis decreased on day 3 and later.

CONCLUSIONS

We suggested that hypercytokinemia in the cord blood in premature infants were greatly related with funisitis. Diagnosis of funisitis would be important to find the premature infants who need to be managed their risk of FIRS. In addition, hypercytokinemia disappeared in a few days after birth; therefore, cord blood data analysis of cytokines and/or inflammation-related proteins concentrations is necessary to evaluate the fetal inflammatory environments in premature infants after birth.