Anti-inflammatory effects of high-dose IgG on TNF-α-activated human coronary artery endothelial cells

Multifaceted Tissue-Protective Functions of Polyvalent Immunoglobulin Preparations in Severe Infections-Interactions with Neutrophils, Complement, and Coagulation Pathways

Severe infections induce immune defense mechanisms and initial tissue damage, which produce an inflammatory neutrophil response. Upon dysregulation of these responses, inflammation, further tissue damage, and systemic spread of the pathogen may occur. Subsequent vascular inflammation and activation of coagulation processes may cause microvascular obstruction at sites distal to the primary site of infection. Low immunoglobulin (Ig) M and IgG levels have been detected in patients with severe infections like sCAP and sepsis, associated with increased severity and mortality. Based on Ig's modes of action, supplementation with polyvalent intravenous Ig preparations (standard IVIg or IgM/IgA-enriched Ig preparations) has long been discussed as a treatment option for severe infections. A prerequisite seems to be the timely administration of Ig preparations before excessive tissue damage has occurred and coagulopathy has developed. This review focuses on nonclinical and clinical studies that evaluated tissue-protective activities resulting from interactions of Igs with neutrophils, complement, and the coagulation system. The data indicate that coagulopathy, organ failure, and even death of patients can possibly be prevented by the timely combined interactions of (natural) IgM, IgA, and IgG with neutrophils and complement.

Intravenous Immunoglobulin: Mechanism of Action in Autoimmune and Inflammatory Conditions

Intravenous immunoglobulin (IVIG) is the mainstay of therapy for humoral immune deficiencies and numerous inflammatory disorders. Although the use of IVIG may be supplanted by several targeted therapies to cytokines, the ability of polyclonal normal IgG to act as an effector molecule as well as a regulatory molecule is a clear example of the polyfunctionality of IVIG. This article will address the mechanism of action of IVIG in a number of important conditions that are otherwise resistant to treatment. In this commentary, we will highlight mechanistic studies that shed light on the action of IVIG. This will be approached by identifying effects that are both common and disease-specific, targeting actions that have been demonstrated on cells and processes that represent both innate and adaptive immune responses.

Efficacy of high-dose intravenous immunoglobulin in severe and critical COVID-19: A retrospective cohort study

Background

Methods

Results

Conclusion

Intravenous immunoglobulin as an important adjunct in the prevention and therapy of coronavirus 2019 disease

The coronavirus disease-19 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) challenged globally with its morbidity and mortality. A small percentage of affected patients (20%) progress into the second stage of the disease clinically presenting with severe or fatal involvement of lung, heart and vascular system, all contributing to multiple-organ failure. The so-called 'cytokines storm' is considered the pathogenic basis of severe disease and it is a target for treatment with corticosteroids, immunotherapies and intravenous immunoglobulin (IVIg). We provide an overview of the role of IVIg in the therapy of adult patients with COVID-19 disease. After discussing the possible underlying mechanisms of IVIg immunomodulation in COVID-19 disease, we review the studies in which IVIg was employed. Considering the latest evidence that show a link between new coronavirus and autoimmunity, we also discuss the use of IVIg in COVID-19 and anti-SARS-CoV-2 vaccination related autoimmune diseases and the post-COVID-19 syndrome. The benefit of high-dose IVIg is evident in almost all studies with a rapid response, a reduction in mortality and improved pulmonary function in critically ill COVID-19 patients. It seems that an early administration of IVIg is crucial for a successful outcome. Studies' limitations are represented by the small number of patients, the lack of control groups in some and the heterogeneity of included patients. IVIg treatment can reduce the stay in ICU and the demand for mechanical ventilation, thus contributing to attenuate the burden of the disease.

Clinical implications of procalcitonin in Kawasaki disease: a useful candidate for differentiating from sepsis and evaluating IVIG responsiveness

OBJECTIVE

Kawasaki disease (KD) is an acute systemic vasculitis and suspected to be triggered by several potential infections in which procalcitonin (PCT) experiences an increase to some extent. However, whether PCT can serve as a useful candidate for differentiating KD from sepsis, and even for predicting incomplete KD, intravenous immunoglobulin (IVIG) nonresponsiveness and coronary artery abnormalities (CAAs) remains unclear.

METHODS

A total of 254 Chinese KD children were enrolled and divided into 6 subgroups, including complete KD, incomplete KD, IVIG-responsive KD, IVIG-nonresponsive KD, KD with CAAs and KD without CAAs. Blood samples were collected from all subjects within 24-h pre- and 48-h post-IVIG infusion, respectively. PCT, C-reactive protein, erythrocyte sedimentation rate and blood cell counts were detected. In addition, both 261 children with sepsis and 251 healthy children sex- and age-matched with KD children were enrolled in the same period.

RESULTS

(1) PCT experienced the highest increase in sepsis patients before antibiotic therapy, followed by acute KD patients and the healthy controls. (2) The proportion of KD patients with a PCT concentration below 0.25 ng/ml was 11 folds higher than that of sepsis patients. (3) PCT had a sensitivity of 91.7% and a specificity of 30.3% at a cutoff value of > 0.15 ng/ml to predict IVIG nonresponsiveness, and the proportion of IVIG-nonresponders with a PCT concentration of 0.25-0.50 ng/ml was 2 folds higher than that of IVIG-responders.

CONCLUSIONS

The PCT concentrations below 0.25 ng/ml may be useful for discriminating KD from sepsis, and moreover, the PCT concentrations of 0.25-0.50 ng/ml may be helpful in predicting IVIG nonresponsiveness.

Leukocyte proteomics coupled with serum metabolomics identifies novel biomarkers and abnormal amino acid metabolism in Kawasaki disease

Kawasaki disease (KD) is a systemic vasculitis that can lead to severe cardiovascular complications, whereas the development and clinical usage of specific biomarkers might help diagnose KD and avoid certain complications. To this end, the molecular profiles of acute KD patients with coronary artery lesions (CAL) were first investigated through leukocyte proteomics and serum metabolomics assays. A total of 269 differentially abundant proteins and 35 differentially abundant metabolites with the top fold-changed levels were identified in acute KD patients compared to those in the healthy controls. Among them, several highly promising candidate marker proteins and metabolites indicative of KD progression were further analysed, such as the increased proteins ALPL, NAMPT, and S100P, as well as the decreased proteins C1QB and apolipoprotein family members. Moreover, metabolites, including succinic acid, dGMP, hyaluronic acid, L-tryptophan, propionylcarnitine, inosine, and phosphorylcholine, were found to be highly accurate at distinguishing between KD patients and healthy controls. Interestingly, the abnormal expression levels of a distinct set of proteins and metabolites in acute KD patients can be restored to normal levels upon intravenous immunoglobulin (IVIG) treatment. Overall, this work has revealed novel biomarkers and abnormal amino-acid metabolism as a prominent feature involved in KD patients with CAL. SIGNIFICANCE: KD is frequently concomitant with the development of life-threatening coronary vasculitis. Here, the profiles of leukocyte proteomics and serum metabolomics in acute KD patients with CALs were first investigated, and several hub molecules identified here could be used as supplemental biomarkers for KD diagnosis. Moreover, the metabolomic abnormalities especially the amino acids are particularly prominent in KD patients. Interestingly, the abnormal expression levels of a distinct set of proteins and metabolites in acute KD patients can be restored to normal levels upon IVIG treatment. Therefore, these findings might help understand the IVIG activities and also the underlying mechanisms of IVIG-resistant patients, thereby providing a new perspective for the exploration of mechanisms related to KD.

Functional benefits of corticosteroid and IVIG combination therapy in a coronary artery endothelial cell model of Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is the most common pediatric systemic vasculitides of unknown etiology. Recent clinical studies led to reappraisal of the usefulness of initial combination therapy of intravenous immunoglobulin (IVIG) plus a corticosteroid for patients with severe KD. However, the molecular mechanisms underlying the clinical benefits of that combination therapy remain unclear. Here, we used cultured human coronary artery endothelial cells (HCAECs), as a mimic of KD, to study the possible mechanisms responsible for the clinical benefits of adding a corticosteroid to standard IVIG therapy for patients with severe KD.

METHODS

HCAECs were stimulated with TNF-α, IL-1α or IL-1β in the presence and absence of high-dose IgG and/or dexamethasone (DEX). The mRNA and protein concentrations for high-mobility group box-1 (HMGB1), IL-1α, IL-6 and granulocyte-colony stimulating factor (G-CSF) in the culture supernatants were measured by quantitative PCR (qPCR) and ELISA, respectively. Apoptosis was evaluated by the caspase 3/7 activities.

RESULTS

DEX, but not IgG, significantly inhibited apoptosis caused by inflammatory stimuli, resulting in effective reduction of HMGB1 and IL-1α protein release by HCAECs. As previously reported, DEX or IgG alone significantly suppressed TNF-α-induced production of IL-6 and G-CSF and mRNA expression, but induction of those cytokines by IL-1 s (IL-1α and IL-1β) was resistant to high-dose IgG.

CONCLUSIONS

A corticosteroid can effectively inhibit the release of HMGB1 and IL-1α, which may be involved in IVIG resistance in KD. Since high-dose IgG does not have such beneficial anti-cytotoxic effects, adding a corticosteroid to standard IVIG therapy may help prevent the progression of IVIG resistance in KD.

High-Dose Intravenous Immunoglobulins in the Treatment of Severe Acute Viral Pneumonia: The Known Mechanisms and Clinical Effects

The current outbreak of viral pneumonia, caused by novel coronavirus SARS-CoV-2, is the focus of worldwide attention. The WHO declared the COVID-19 outbreak a pandemic event on Mar 12, 2020, and the number of confirmed cases is still on the rise worldwide. While most infected individuals only experience mild symptoms or may even be asymptomatic, some patients rapidly progress to severe acute respiratory failure with substantial mortality, making it imperative to develop an efficient treatment for severe SARS-CoV-2 pneumonia alongside supportive care. So far, the optimal treatment strategy for severe COVID-19 remains unknown. Intravenous immunoglobulin (IVIg) is a blood product pooled from healthy donors with high concentrations of immunoglobulin G (IgG) and has been used in patients with autoimmune and inflammatory diseases for more than 30 years. In this review, we aim to highlight the known mechanisms of immunomodulatory effects of high-dose IVIg therapy, the immunopathological hypothesis of viral pneumonia, and the clinical evidence of IVIg therapy in viral pneumonia. We then make cautious therapeutic inferences about high-dose IVIg therapy in treating severe COVID-19. These inferences may provide relevant and useful insights in order to aid treatment for COVID-19.

Currently available intravenous immunoglobulin contains antibodies reacting against severe acute respiratory syndrome coronavirus 2 antigens

Aim: There is a critical need for effective therapies that are immediately available to control the spread of COVID-19 disease. Material & methods: Gamunex®-C and Flebogamma® DIF (Grifols) intravenous immunoglobulin (IVIG) products were tested using ELISA techniques for antibodies against several antigens of human common betacoronaviruses that may crossreact with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Results: Both IVIGs showed consistent reactivity to components of the tested viruses. Positive crossreactivity was seen in SARS-CoV, middle east respiratory syndrome-CoV and SARS-CoV-2. For SARS-CoV-2, positive reactivity was observed at IVIG concentrations ranging from 100 μg/ml with Gamunex-C to 1 mg/ml with Flebogamma 5% DIF. Conclusion: Gamunex-C and Flebogamma DIF contain antibodies reacting against SARS-CoV-2 antigens. Studies to confirm the utility of IVIG preparations for COVID-19 management may be warranted.

Clinical observation of noncoronary cardiac abnormalities in Chinese children with Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is an acute, self-limited vasculitis. Coronary artery aneurysm (CAA) serves as a major contributor to the long-term prognosis of KD. In addition, acute KD usually also leads to several kinds of noncoronary cardiac abnormalities (NCA) involving the pericardium, myocardium and endocardium.

MATERIALS AND METHODS

A total of 142 Chinese children with KD were recruited from July 2015 to April 2018. Blood samples were collected at 24 hours pre-intravenous immunoglobulin (IVIG) therapy. Several inflammatory mediators and biomarkers for acute myocardial infarction were detected. Echocardiography and electrocardiography (ECG) were performed.

RESULTS

Plasma white blood cell counts (WBC) were significantly increased in patients with IVIG-nonresponsive KD when compared with their IVIG-responsive counterparts. A total of 106 children (74.65%) suffered from NCA, including 8 patients (5.63%) with pericardial effusion, 23 patients (16.20%) with acute myocarditis, 101 patients (71.13%) with valvular regurgitation and 8 patients (5.63%) with abnormal ECG. No significant differences were observed in the distribution of clinical classification and the response to IVIG therapy regardless of NCA exhibited or not.

CONCLUSIONS

Noncoronary cardiac abnormalities is almost universal in acute KD and mainly manifests as valvular regurgitation. However, it has no influence on clinical classification and the response to IVIG therapy.

White Blood Cell and Neutrophil Counts and Response to Intravenous Immunoglobulin in Kawasaki Disease

We explored parameters to predicting the efficacy of intravenous immunoglobulin (IVIG) therapy for patients with Kawasaki disease (KD). We retrospectively analyzed the laboratory data of 77 children with KD treated with IVIG. Data obtained before and within 24 hours after IVIG therapy were compared between responders and nonresponders. The white blood cell (WBC) and neutrophil counts were significantly lower in responders than nonresponders within 24 hours after IVIG. The areas under the receiver operating characteristics curves of the WBC and neutrophil counts were 0.846 and 0.754, respectively. The WBC and neutrophil counts differed significantly between responders and nonresponders (the latter developed recurrent pyrexia after transient fever resolution). In conclusion, WBC and neutrophil counts within 24 hours after IVIG usefully predict the efficacy of IVIG therapy for those with KD, and identify nonresponders to such therapy.

Neutralizing effects of anti-infliximab antibodies on synergistically-stimulated human coronary artery endothelial cells

BACKGROUND AND AIMS

Patients with rheumatic diseases have an increased risk of atherosclerosis with up-regulated serum amyloid A (SAA), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), which were reported to activate human coronary artery endothelial cells (HCAEC). We aimed to investigate the effects of TNF-α inhibitor infliximab and anti-infliximab antibodies on the TNF-α/IL-1β/SAA activated HCAEC.

METHODS

HCAEC were incubated with TNF-α, IL-1β, SAA, infliximab, anti-infliximab antibodies and their combinations. The protein levels of pro- and anti-atherogenic analytes were measured in supernatants using ELISA and multiplex assays, while mRNA expression was determined by RT-PCR. Anti-infliximab antibodies were purified from sera samples by affinity chromatography.

RESULTS

IL-6, IL-8, GM-CSF and GRO-α were synergistically up-regulated in triple stimulation with TNF-α, IL-1β and SAA, while their levels in solely SAA- or TNF-α-stimulated HCAEC did not increase. IL-1Ra, IL-1α, VCAM-1, MCP-1, IL-10 and IL-17A were increased, but no synergistic responses were observed in triple stimulation. Infliximab was effective in lowering the synergistic effect of IL-6, IL-8, GM-CSF and GRO-α in triple stimulation, while anti-infliximab antibodies restored the levels. The changes were confirmed at the mRNA expression level for IL-6, IL-8 and GM-CSF.

CONCLUSIONS

Triple stimulation with TNF-α, IL-1β and SAA synergistically elevated IL-6, IL-8, GM-CSF and GRO-α release in supernatants of HCAEC, with infliximab substantially inhibiting their levels. An isolated, enriched fraction of polyclonal anti-infliximab antibodies was capable of neutralizing infliximab, in the presence of TNF-α/IL-1β/SAA. The long-term presence of anti-infliximab antibodies in the circulation of patients with chronic rheumatic diseases is potentially important for promoting the atherosclerotic process.

The time option of IVIG treatment is associated with therapeutic responsiveness and coronary artery abnormalities but not with clinical classification in the acute episode of Kawasaki disease

BACKGROUND

In the last decade, incomplete Kawasaki disease (KD), intravenous immunoglobulin (IVIG) non-response and coronary artery abnormalities (CAA) have experienced the increasing trends in China. In addition, the enhancement of pediatricians' awareness may also raise the diagnostic rate of incomplete KD and stimulate more aggressive initial therapy in the acute episode of KD. Given this background, we hypothesize that the time option of IVIG treatment should be in parallel with peak time of systemic inflammation; either earlier or later IVIG treatment may affect the clinical classification, therapeutic responsiveness and CAA occurrence in KD patients. Therefore, the major objective of the present study is to identify whether the time option of IVIG treatment could be associated with the clinical classification, therapeutic responsiveness and CAA occurrence in the acute episode of KD.

MATERIALS AND METHODS

A total of 153 children with KD were recruited between July 2015 and May 2018. All patients received the standard therapy of KD, including a single infusion of IVIG (2 g/kg) and aspirin (30-50 mg/kg/d). Blood samples were collected from all subjects within 24 h pre-IVIG treatment, respectively. Echocardiography was performed during the period from 2 days to 14 days after IVIG treatment.

RESULTS

(1) The clinical classification presented no significant heterogenicity among different treatment time (x2 = 1.59, p > 0.05) (2) Eleven KD patients resisted to IVIG treatment and 7 of them (63.60%) received the initial IVIG dose on day 5 and 6. (3) The distribution of CAA onset was subjected to a significant difference according to timing option of IVIG treatment (x2 = 11.94, p < 0.05).

CONCLUSIONS

The time option of IVIG treatment is associated with therapeutic responsiveness and CAA but not with clinical classification in the acute episode of KD.

The effects of human immunoglobulin G on enhancing tissue protection and neurobehavioral recovery after traumatic cervical spinal cord injury are mediated through the neurovascular unit

Background

Spinal cord injury (SCI) is a condition with few effective treatment options. The blood-spinal cord barrier consists of pericytes, astrocytes, and endothelial cells, which are collectively termed the neurovascular unit. These cells support spinal cord homeostasis by expressing tight junction proteins. Physical trauma to the spinal cord disrupts the barrier, which leads to neuroinflammation by facilitating immune cell migration to the damaged site in a process involving immune cell adhesion. Immunosuppressive strategies, including methylprednisolone (MPSS), have been investigated to treat SCI. However, despite some success, MPSS has the potential to increase a patient’s susceptibility to wound infection and impaired wound healing. Hence, immunomodulation may be a more attractive approach than immunosuppression. Approved for modulating neuroinflammation in certain disorders, including Guillain-Barre syndrome, intravenous administration of human immunoglobulin G (hIgG) has shown promise in the setting of experimental SCI, though the optimal dose and mechanism of action remain undetermined.

Methods

Female adult Wistar rats were subjected to moderate-severe clip compression injury (35 g) at the C7-T1 level and randomized to receive a single intravenous (IV) bolus of hIgG (0.02, 0.2, 0.4, 1, 2 g/kg), MPSS (0.03 g/kg), or control buffer at 15 min post-SCI. At 24 h and 6 weeks post-SCI, molecular, histological, and neurobehavioral effects of hIgG were analyzed.

Results

At 24 h post-injury, human immunoglobulin G co-localized with spinal cord pericytes, astrocytes, and vessels. hIgG (2 g/kg) protected the spinal cord neurovasculature after SCI by increasing tight junction protein expression and reducing inflammatory enzyme expression. Improvements in vascular integrity were associated with changes in spinal cord inflammation. Interestingly, hIgG (2 g/kg) increased serum expression of inflammatory cytokines and co-localized (without decreasing protein expression) with spinal cord vascular cell adhesion molecule-1, a protein used by immune cells to enter into inflamed tissue. Acute molecular benefits of hIgG (2 g/kg) led to greater tissue preservation, functional blood flow, and neurobehavioral recovery at 6 weeks post-SCI. Importantly, the effects of hIgG (2 g/kg) were superior to control buffer and hIgG (0.4 g/kg), and comparable with MPSS (0.03 g/kg).

Conclusions

hIgG (2 g/kg) is a promising therapeutic approach to mitigate secondary pathology in SCI through antagonizing immune cell infiltration at the level of the neurovascular unit.

Monocyte-Derived Interleukin-1β As the Driver of S100A12-Induced Sterile Inflammatory Activation of Human Coronary Artery Endothelial Cells: Implications for the Pathogenesis of Kawasaki Disease

OBJECTIVE

Kawasaki disease (KD) is an acute vasculitis of childhood, predominantly affecting the coronary arteries. S100A12, a granulocyte-derived agonist of both the receptor for advanced glycation end products (RAGE) and Toll-like receptor 4 (TLR-4), is strongly up-regulated in KD. This study was undertaken to investigate the potential contributions of S100A12 to the pathogenesis of KD.

METHODS

Serum samples from patients with KD (n = 30) at different stages pre- and post-intravenous immunoglobulin (IVIG) treatment were analyzed for the expression of S100A12, cytokines, chemokines, and soluble markers of endothelial cell activation. Primary human coronary artery endothelial cells (HCAECs) were analyzed for responsiveness to direct stimulation with S100A12 or lipopolysaccharide (LPS), as assessed by real-time quantitative reverse transcription-polymerase chain reaction analysis of cytokine and endothelial cell adhesion molecule messenger RNA expression. Alternatively, HCAECs were cultured in conditioned medium obtained from primary human monocytes that were stimulated with LPS or S100A12 in the absence or presence of IVIG or cytokine antagonists.

RESULTS

In the serum of patients with KD, pretreatment S100A12 levels were associated with soluble vascular cell adhesion molecule 1 titers in the course of IVIG therapy (r_s = -0.6, P = 0.0003). Yet, HCAECs were not responsive to direct S100A12 stimulation, despite the presence of appropriate receptors (RAGE, TLR-4). HCAECs did, however, respond to supernatants obtained from S100A12-stimulated primary human monocytes, as evidenced by the gene expression of inflammatory cytokines and adhesion molecules. This response was strictly dependent on interleukin-1β (IL-1β) signaling (P < 0.001).

CONCLUSION

In its role as a highly expressed mediator of sterile inflammation in KD, S100A12 appears to activate HCAECs in an IL-1β-dependent manner. These data provide new mechanistic insights into the contributions of S100A12 and IL-1β to disease pathogenesis, and may therefore support current IL-1-targeting studies in the treatment of patients with KD.

TNF-α is superior to conventional inflammatory mediators in forecasting IVIG nonresponse and coronary arteritis in Chinese children with Kawasaki disease

BACKGROUND

Tumor necrosis factor (TNF) -α is of inflammatory cytokines produced chiefly by activated monocyte/macrophages, and has been implicated in the pathogenesis of Kawasaki disease (KD). We elucidated the relationship of plasma TNF-α with conventional inflammatory mediators, clinical classification, intravenous immunoglobulin (IVIG) response and coronary arteritis in the course of KD.

METHODS

Seventy Chinese children with KD were enrolled and divided into 6 subgroups, including complete KD, incomplete KD, IVIG-responsive KD, IVIG-nonresponsive KD, coronary artery (CA) -noninvolvement KD and CA-involvement KD. Blood samples were collected from all subjects at 24h pre- and 48h post-IVIG therapy, respectively. TNF-α, white blood cells counts (WBC), absolute neutrophil counts (ANC), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and procalcitonin (PCT) were detected.

RESULTS

Plasma TNF-α markedly increased in the acute phase of KD and was positively correlated with CRP and PCT, whereas remained high after IVIG therapy. TNF-α as well as conventional inflammatory mediators could not be used to differentiate the clinical classification of KD, but they may prove beneficial to heighten or reduce the suspicion of incomplete KD. Plasma TNF-α was significantly higher in both IVIG-nonresponsive patients and coronary arteritis patients, but no significant differences were observed in all the other inflammatory mediators. Moreover, plasma TNF-α was positively correlated with the internal diameter of CA.

CONCLUSIONS

TNF-α is superior to conventional inflammatory mediators in forecasting IVIG nonresponse and coronary arteritis in Chinese children with KD.

Transient Deformation of Neutrophils in Kawasaki Disease

In the treatment of Kawasaki disease, resistance to high-dose immunoglobulin intravenous (IGIV) can occur. The neutrophil morphology analyses in 17 patients revealed that transient pseudo-Pelger-Huët anomaly was more frequently detected in the IGIV-resistant group. This finding may aid the prediction of IGIV resistance.

Utility of ferritin as a predictor of the patients with Kawasaki disease refractory to intravenous immunoglobulin therapy

OBJECTIVES

The aim of this study is to investigate whether ferritin can be a useful marker for the prediction of the patients with Kawasaki disease (KD) refractory to initial intravenous immunoglobulin (IVIG) therapy.

METHODS

This retrospective study enrolled 85 patients with KD hospitalized at Kitakyushu General Hospital during 2010-2014. These patients were divided into IVIG responders (n = 57) and non-responders (n = 28). Serum ferritin levels and the scoring systems for the prediction of non-responsiveness to initial IVIG therapy were compared between these two groups.

RESULTS

Serum ferritin level was significantly elevated in non-responders (p = 0.010). The area under the receiver-operating characteristics curve was 0.674, and the sensitivity and specificity in more than 165 ng/ml of serum ferritin level were 70.4% and 63.2%, respectively. In two of the three prediction scoring systems, non-responders also showed significantly higher scores than responders, but many non-responders had low scores of these scoring systems. More than half of the patients with a low score of these scoring systems had high serum ferritin level (≥ 165 ng/ml).

CONCLUSIONS

Serum ferritin level might be a useful marker for the prediction of non-responsiveness to initial IVIG therapy and could be an important complementary marker to the prediction scoring systems.

Silica and double-stranded RNA synergistically induce bronchial epithelial apoptosis and airway inflammation

Silica crystals (silica), which are the main mineral component of volcanic ash and desert dust, can activate the caspase-1-activating inflammasome in phagocytic cells to secrete IL-1β. Although inhalation of silica-containing dust is known to exacerbate chronic respiratory diseases, probably through inflammasome activation, its direct effects on bronchial epithelial cells remain unclear. Here, we show that silica and double-stranded RNA (dsRNA) synergistically induces caspase-9-dependent apoptosis, but not inflammasome activation, of bronchial epithelial cells. Intranasal administration of silica and dsRNA to mice synergistically enhanced neutrophil infiltration in the airway without IL-1β release in the bronchoalveolar lavage fluid. Histopathological analysis revealed that silica or dsRNA alone induced slight airway inflammation, whereas combined administration significantly enhanced airway inflammation and epithelial damage. These novel findings suggest that inhalation of silica-containing dust may cause inflammasome-independent airway inflammation, possibly by damaging the epithelial barrier, especially at the time of viral infection. These responses may also be involved in acute lung injury caused by inhaled silica-containing dust.

Transplantation of Achilles tendon treated with bone morphogenetic protein 7 promotes meniscus regeneration in a rat model of massive meniscal defect

Objective

This study was undertaken to examine whether bone morphogenetic protein 7 (BMP-7) induces ectopic cartilage formation in the rat tendon, and whether transplantation of tendon treated with BMP-7 promotes meniscal regeneration. Additionally, we analyzed the relative contributions of host and donor cells on the healing process after tendon transplantation in a rat model.

Methods

BMP-7 was injected in situ into the Achilles tendon of rats, and the histologic findings and gene profile were evaluated. Achilles tendon injected with 1 μg of BMP-7 was transplanted into a meniscal defect in rats. The regenerated meniscus and articular cartilage were evaluated at 4, 8, and 12 weeks. Achilles tendon from LacZ-transgenic rats was transplanted into the meniscal defect in wild-type rats, and vice versa.

Results

Injection of BMP-7 into the rat Achilles tendon induced the fibrochondrocyte differentiation of tendon cells and changed the collagen gene profile of tendon tissue to more closely approximate meniscal tissue. Transplantation of the rat Achilles tendon into a meniscal defect increased meniscal size. The rats that received the tendon treated with BMP-7 had a meniscus matrix that exhibited increased Safranin O and type II collagen staining, and showed a delay in articular cartilage degradation. Using LacZ-transgenic rats, we determined that the regeneration of the meniscus resulted from contribution from both donor and host cells.

Conclusion

Our findings indicate that BMP-7 induces ectopic cartilage formation in rat tendons. Transplantation of Achilles tendon treated with BMP-7 promotes meniscus regeneration and prevents cartilage degeneration in a rat model of massive meniscal defect. Native cells in the rat Achilles tendon contribute to meniscal regeneration.

Kawasaki disease: part I. Diagnosis, clinical features, and pathogenesis

Kawasaki disease, or mucocutaneous lymph node syndrome, most commonly affects children between 6 months and 5 years of age. Approximately 90% of patients have mucocutaneous manifestations. This article will focus on the epidemiology of Kawasaki disease in the United States as it relates to other countries, the diagnosis of Kawasaki disease, its clinical course, and the currently accepted theories of pathogenesis. A particular focus is given to the various dermatologic manifestations that may occur.