Immune-monitoring in Kawasaki disease patients treated with infliximab and intravenous immunoglobulin

Intravenous Immunoglobulin in Kawasaki Disease-Evolution and Pathogenic Mechanisms

Kawasaki disease (KD) is an acute vasculitis of childhood that affects the medium vessels with a special predilection to the involvement of coronary arteries. The major morbidity of this disease is due to coronary artery aneurysm, which occurs in about 25-30% of untreated cases. For decades now, intravenous immunoglobulin (IVIg) has consistently been shown to reduce the risk of CAAs to less than 5%. However, the mechanism of immunomodulation remains unclear. Several studies on the role of IVIg in the modulation of toll-like receptor pathways, autophagy, and apoptosis of the mononuclear phagocytic system, neutrophil extracellular trap, and dendritic cell modulation suggest a modulatory effect on the innate immune system. Similarly, certain studies have shown its effect on T-cell differentiation, cytokine release, and regulatory T-cell function. In this review, we discuss the potential mechanisms underlying the immunomodulatory actions of IVIg in patients with Kawasaki disease. Furthermore, we provide a summary of the evidence regarding various infusion protocols and dosages utilized in the treatment of KD patients.

Intravenous Immunoglobulin Therapy Restores the Quantity and Phenotype of Circulating Dendritic Cells and CD4+ T Cells in Children With Acute Kawasaki Disease

Background

Intravenous immunoglobulin (IVIG) showed its therapeutic efficacy on Kawasaki disease (KD). However, the mechanisms by which it reduces systemic inflammation are not completely understood. Dendritic cells (DCs) and T cells play critical roles in the pathogenic processes of immune disorders. Assessing the quantity of DC subsets and T cells and identifying functional molecules present on these cells, which provide information about KD, in the peripheral blood may provide new insights into the mechanisms of immunoglobulin therapy.

Methods

In total, 54 patients with KD and 27 age-matched healthy controls (HCs) were included in this study. The number, percentage, and phenotype of DC subsets and CD4⁺ T cells in peripheral blood were analyzed through flow cytometry.

Results

Patients with KD exhibited fewer peripheral DC subsets and CD4⁺ T cells than HCs. Human leucocyte antigen-DR (HLA-DR) expression was reduced on CD1c⁺ myeloid DCs (CD1c⁺ mDCs), whereas that on plasmacytoid DCs (pDCs) did not change significantly. Both pDCs and CD1c⁺ mDCs displayed significantly reduced expression of co-stimulatory molecules, including CD40, CD86. pDCs and CD1c⁺ mDCs presented an immature or tolerant phenotype in acute stages of KD. Number of circulating pDC and CD1c⁺ mDC significantly inversely correlated with plasma interleukin-6 (IL-6) levels in KD patients pre-IVIG treatment. No significant differences were found concerning the DC subsets and CD4⁺ T cells in patients with KD with and without coronary artery lesions. Importantly, these altered quantity and phenotypes on DC subsets and CD4⁺ T cells were restored to a great extent post-IVIG treatment. T helper (Th) subsets including Th1 and Th2 among CD4⁺ T cells did not show alteration pre- and post-IVIG treatment, although the Th1-related cytokine IFN-γ level in plasma increased dramatically in patients with KD pre-IVIG treatment.

Conclusions

pDCs and CD1c⁺ mDCs presented an immature or tolerant phenotype in acute stages of KD, IVIG treatment restored the quantity and functional molecules of DCs and CD4⁺ T cells to distinct levels in vivo, indicating the involvement of DCs and CD4⁺ T cells in the inflammation in KD. The findings provide insights into the immunomodulatory actions of IVIG in KD.

Anakinra Treatment in Patients with Acute Kawasaki Disease with Coronary Artery Aneurysms: A Phase I/IIa Trial

OBJECTIVES

To determine the safety, pharmacokinetics, and immunomodulatory effects of 2-6 weeks of anakinra therapy in patients with acute Kawasaki disease with a coronary artery aneurysm (CAA).

STUDY DESIGN

We performed a Phase I/IIa dose-escalation study of anakinra (2-11 mg/kg/day) in 22 patients with acute Kawasaki disease with CAA. We measured interleukin (IL)-1RA concentrations after the first dose and trough levels up to study week 6. Markers of inflammation and coronary artery z-scores were assessed pretreatment and at 48 hours, 2 weeks, and 6 weeks after initiation of therapy.

RESULTS

Up to 6 weeks of anakinra (up to 11 mg/kg/day) was safe and well tolerated by the 22 participants (median age, 1.1 years), with no serious adverse events attributable to the study drug. All participants were treated with intravenous immunoglobulin (IVIG), and 20 also received infliximab (10 mg/kg) before initiation of anakinra. Serum levels of IL-6, IL-8, and tumor necrosis factor α decreased similarly in patients with Kawasaki disease treated with IVIG, infliximab, and anakinra compared with age- and sex-matched patients with Kawasaki disease treated only with IVIG and infliximab. Anakinra clearance increased with illness day at diagnosis. Simulations demonstrated that more frequent intravenous (IV) dosing may result in more sustained concentrations without significantly increasing the peak concentration compared with subcutaneous (SC) dosing.

CONCLUSIONS

Both IV and SC anakinra are safe in infants and children with acute Kawasaki disease and CAA. IV dosing every 8-12 hours during the acute hospitalization of patients with Kawasaki disease may result in a sustained concentration while avoiding frequent SC injections. The efficacy of a short course of IV therapy during hospitalization should be studied. TRIAL REGISTRATION CLINICALTRIALS.GOV: NCT02179853.

Atlas of circulating immune cells in Kawasaki disease

Increasing evidence shows that the pathogenesis of Kawasaki disease (KD) is caused by abnormal and unbalanced innate and adaptive immune responses. However, the changes in and functions of adaptive immune cells in the peripheral blood of subjects with KD remain controversial. In this study, three different methods, CIBERSORT, Immune Cell Abundance Identifier (ImmuCellAI), and immune cell markers, were used to evaluate the proportions and abundances of immune cells in eight KD datasets (GSE9863, GSE9864, GSE18606, GSE63881, GSE68004, GSE73461, GSE73463, and GSE64486; a total of 1,251 samples). Compared with those in normal controls and convalescent KD samples, the proportions and abundances of innate immune cells such as neutrophils, monocytes, and macrophages in acute KD peripheral blood samples were significantly increased, while those of adaptive immune cells such as B and T cells were significantly decreased. The change tendencies of these immune cells were similar to those observed in other febrile illnesses but were more significant. However, in the coronary artery tissues of patients with convalescent KD, adaptive immune cells, especially B cells and CD8+ T cell subsets, were significantly increased. This result suggests that adaptive immune cells can be selectively recruited from peripheral blood into the coronary arteries. In addition, we found that elevated neutrophils in peripheral blood could be used as a biomarker to assist in the differential diagnosis of KD, but we did not find immune cells that could accurately predict intravenousimmunoglobulin (IVIG) responses in multiple datasets.

SARS-CoV-2-specific T cell responses and immune regulation in infected pregnant women

We studied the T cell response to SARS-CoV-2 spike and non-spike peptide epitopes in eight convalescent pregnant women together with the immune monitoring that included innate tolerogenic dendritic cell populations important to maintain the immunological mother/fetus interface to address a potential risk for the antiviral cellular response in the outcome of pregnancy. Four subjects had pre-existing chronic inflammatory conditions that could have potentially affected the SARS-CoV-2-specific T cell response. Seven of eight subjects responded to SARS-CoV-2 peptides with differences within CD4+ T helper (Th) and CD8+ cytotoxic T cells (CTL). SARS-CoV-2-specific inducible regulatory T cells (iTreg) were numerous in circulation. CD4+ T cell memory included central memory T cells (T_CM) and effector memory (T_EM). As far as the CD8+ memory repertoire, T_CM and T_EM were very low or absent in eight of eight subjects and only effector cells that revert to CD45RA+, defined as T_EMRA were measurable in circulation. T cells were in the normal range in all subjects regardless of pre-existing inflammatory conditions. The immune phenotype indicated the expansion and activation of tolerogenic myeloid dendritic cells including CD14+ cDC2 and CD4+ ILT-4+ tmDC. In summary, SARS-CoV-2 infection induced a physiological anti-viral T cell response in pregnant women that included SARS-CoV-2-specific iTreg with no negative effects on the tolerogenic innate dendritic cell repertoire relevant to the immune homeostasis of the maternal-fetal interface. All eight subjects studied delivered full-term, healthy infants.

A Retrospective Cohort Study of Intravenous Immunoglobulin Therapy in the Acute Phase of Kawasaki Disease: The Earlier, the Better?

Background

Although intravenous immunoglobulin (IVIG) is expected to prevent coronary artery abnormalities of Kawasaki disease (KD) in the acute phase, the timing and effectiveness of IVIG remain to be determined. The association of timing of IVIG administration in KD patients with coronary artery abnormalities is evaluated in this cohort study.

Methods

We systematically studied KD patients from two participating institutions between 2015 and 2017. To reveal the effectiveness of IVIG treatment, these patients were classified into four groups regarding the time of IVIG treatment. Primary outcome was coronary artery abnormalities by echo at diagnosis and 12 months follow-up; secondary outcomes included inflammatory markers.

Results

A total of 1281 patients were included in this study. The best time of IVIG treatment cut-off values in 12 months follow-up for predicting coronary artery abnormalities was days 7.5 of illness onset. According to the best time of IVIG treatment cut-off values, all patients were classified into 4 groups. Group 1 was defined as earlier IVIG treatment administration on days ≤4 of the illness (n = 77). Group 2 was defined with days 5-7 (n = 817), group 3 with days 8-10 (n = 249), group 4 with days >10 (n = 138). A greater proportion of IVIG-resistant KD patients were group 4 than the other three groups, and there were significant differences (p < 0.05). The incidence of coronary artery lesions (CALs) and coronary artery aneurysms (CAAs) in group 3 and group 4 was higher than that in group 1 (p < 0.05) and group 2 (p < 0.05) during a 12-month follow-up. Additionally, the incidence of CALs in group 1 was higher than that in group 2 but without statistical significance (p > 0.05). The OR was significantly higher for those who started IVIG administration more than 7 days from the onset was positively associated with the occurrence of CALs (OR, 5.3; 95% CI, 2.0-13.9) and CAAs (OR, 13.5; 95% CI, 2.9-14.1) 12 months after initial onset. Multivariate regression revealed that the timing of IVIG treatment and IVIG-resistance was independent risk factors of CALs.

Conclusions

IVIG treatment less than 7 days after illness onset are found to be sufficient for preventing developing coronary artery abnormalities in KD patients. Earlier IVIG treatment administration within 4 days may not increase the higher incidence of coronary artery abnormalities and IVIG resistance (Chinese Clinical Trial Registry:ChiCTR1800015800).

High Dose Intravenous IgG Therapy Modulates Multiple NK Cell and T Cell Functions in Patients With Immune Dysregulation

Intravenous immunoglobulin (IVIG) is an effective immunomodulatory treatment for immune dysregulation diseases. However, the mechanisms by which it reduces systemic inflammation are not well understood. NK cell cytotoxicity is decreased by IVIG in women with reduced fertility, but IVIG effects on NK cells in immune dysregulation are less clear. We hypothesized that IVIG modulation of lymphocyte function, especially in NK cells, is important for resolution of inflammation. Our aim was to identify IVIG-induced changes in a cohort of patients with Kawasaki disease (KD) and those that occur broadly in pediatric patients with various immune dysregulatory diseases. Peripheral blood mononuclear cells (PBMCs) of patients with KD or autoimmune/inflammatory diseases were phenotyped pre and post high dose IVIG treatment by flow cytometry. In KD patients, after IVIG infusion T_reg cell frequency and the proportion of activated CD25⁺ immunoregulatory CD56^bright NK cells was increased, and multiple lymphocyte subsets showed increased expression of the lymphoid tissue homing receptor CD62L. Importantly, IVIG treatment decreased the frequency of cells expressing the degranulation marker CD107a among cytotoxic CD56^dim NK cells, which was reflected in a significant reduction in target cell killing and in decreased production of multiple pro-inflammatory mediators. Interestingly, the activating receptor CD336 was expressed on a higher proportion of CD56^bright NK cells after IVIG in both KD and autoimmune/inflammatory patients while other NK receptors were increased differentially in each cohort. In autoimmune/inflammatory patients IVIG induced the proliferation marker CD71 on a higher percentage of CD56^dim NK cells, and in contrast to KD patients, CD107a⁺ cells were increased in this subset. Furthermore, when PBMCs were stimulated ex vivo with IL-2 or Candida antigen in autologous plasma, more of the CD4⁺ T cells of KD patients expressed CD25 after IVIG therapy but fewer cytotoxic T cells were degranulated based on CD107a expression. In summary, IVIG treatment in patients with immune dysregulation has multiple effects, especially on NK cell subsets and CD4⁺ T cells, which are compatible with promoting resolution of inflammation. These novel findings provide insight into the immunomodulatory actions of IVIG in autoimmune and inflammatory conditions.

Efficacy of infliximab in the treatment of Kawasaki disease: A systematic review and meta-analysis

The present study aimed to review the relevant studies in order to determine the efficacy of infliximab (IFX) in the treatment of Kawasaki disease (KD). The relevant studies were retrieved using the PubMed, Cochrane and Embase databases. Key sources in the literature were reviewed; all articles published by July 2019 were considered for inclusion. For each study, odds ratios, mean difference and 95% confidence interval (95% CI) were assessed to evaluate study outcomes. A total of 16 studies involving 429 patients were relevant to the questions of interest of the current meta-analysis. Compared with intravenous immunoglobulin (IVIG), IFX or IFX plus IVIG significantly reduced the incidence of adverse events, including the number of patients with fever, changes in lip and oral cavity and/or cervical lymphadenopathy. The white blood cell (WBC), neutrophil and C-reactive protein (CRP) levels were also reduced in the IFX or IFX plus IVIG group compared with those in the IVIG or polyethylene glycol-treated human immunoglobulin (VGIH) groups. The platelet counts, alanine aminotransferase (ALT) levels and Z-scores were increased in the IFX or IFX plus IVIG groups compared with those in the IVIG or VGIH groups. In the single-arm studies, the incidence of coronary artery aneurysm was 0.150 (95% CI: 0.024, 0.277), the non-response rate was 0.097 (95% CI: 0.056, 0.138), and the incidence of adverse events was 0.156 (95% CI: 0.122, 0.190). IFX not only effectively reduced the incidence of fever, conjunctival injection, changes in lip and oral cavity and cervical lymphadenopathy polymorphous exanthema, but also the WBC, neutrophil, ALT and CRP levels. The platelet levels were increased in patients after the IFX therapy compared with patients in the IVIG or VGIH groups. IFX or IFX plus IVIG exhibited improved clinical efficacy in the treatment of KD compared with that of IVIG or VGIH. However, as a limited number of studies was included in the current study, the findings should be verified further.

Characterization of circulating immune cells in acute Kawasaki disease suggests exposure to different antigens

Kawasaki disease (KD) is an acute pediatric vasculitis of unknown etiology that can cause coronary artery aneurysms, and is the leading cause of acquired heart disease in children. We studied aspects of the innate and adaptive immune response in 17 acute KD children prior to treatment with intravenous immunoglobulin. Distinct patterns within the innate immune response correlated with specific clinical features. Proinflammatory myeloid dendritic cells (mDC) were abundant in four of 17 (23·5%) subjects who were older and manifested severe inflammation with clinical myocarditis and elevated hepatobiliary enzyme levels. Of the nine subjects with low levels of anti‐inflammatory, tolerogenic mDC, six had enlarged cervical lymph nodes at diagnosis. In contrast, the adaptive immune repertoire varied greatly with no discernible patterns or associations with clinical features. Two subjects with aneurysms had numerous circulating CD8⁺ T cells. Ten subjects showed low CD4⁺ T cell numbers and seven subjects had CD4⁺ T cells in the normal range. CD4⁺ T cells expressed interleukin‐7 receptor (IL‐7R), suggesting repeated antigenic stimulation. Thymic‐derived regulatory T cells (nT_reg) and peripherally induced regulatory T cells (iT_reg) were also enumerated, with the majority having the nT_reg phenotype. Natural killer (NK) and NK T cell numbers were similar across all subjects. Taken together, the results of the immune monitoring suggest that KD may have multiple triggers that stimulate different arms of the innate and adaptive compartment in KD patients. Thus, it is possible that diverse antigens may participate in the pathogenesis of KD.

Engineering of Fc Multimers as a Protein Therapy for Autoimmune Disease

The success of Intravenous Immunoglobulin in treating autoimmune and inflammatory processes such as immune thrombocytopenia purpura and Kawasaki disease has led to renewed interest in developing recombinant molecules capable of recapitulating these therapeutic effects. The anti-inflammatory properties of IVIG are, in part, due to the Fc region of the IgG molecule, which interacts with activating or inhibitory Fcγ receptors (FcγRs), the neonatal Fc Receptor, non-canonical FcRs expressed by immune cells and complement proteins. In most cases, Fc interactions with these cognate receptors are dependent upon avidity—avidity which naturally occurs when polyclonal antibodies recognize unique antigens on a given target. The functional consequences of these avid interactions include antibody dependent cell-mediated cytotoxicity, antibody dependent cell phagocytosis, degranulation, direct killing, and/or complement activation—all of which are associated with long-term immunomodulatory effects. Many of these immunologic effects can be recapitulated using recombinant or non-recombinant approaches to induce Fc multimerization, affording the potential to develop a new class of therapeutics. In this review, we discuss the history of tolerance induction by immune complexes that has led to the therapeutic development of artificial Fc bearing immune aggregates and recombinant Fc multimers. The contribution of structure, aggregation and N-glycosylation to human IgG: FcγR interactions and the functional effect(s) of these interactions are reviewed. Understanding the mechanisms by which Fc multimers induce tolerance and attempts to engineer Fc multimers to target specific FcγRs and/or specific effector functions in autoimmune disorders is explored in detail.

Phase I/IIa Trial of Atorvastatin in Patients with Acute Kawasaki Disease with Coronary Artery Aneurysm

OBJECTIVES

To determine the safety, tolerability, pharmacokinetics, and immunomodulatory effects of a 6-week course of atorvastatin in patients with acute Kawasaki disease with coronary artery (CA) aneurysm (CAA).

STUDY DESIGN

This was a Phase I/IIa 2-center dose-escalation study of atorvastatin (0.125-0.75 mg/kg/day) in 34 patients with Kawasaki disease (aged 2-17 years) with echocardiographic evidence of CAA. We measured levels of the brain metabolite 24(S)-hydroxycholesterol (24-OHC), serum lipids, acute-phase reactants, liver enzymes, and creatine phosphokinase; peripheral blood mononuclear cell populations; and CA internal diameter normalized for body surface area before atorvastatin treatment and at 2 and 6 weeks after initiation of atorvastatin treatment.

RESULTS

A 6-week course of up to 0.75 mg/kg/day of atorvastatin was well tolerated by the 34 subjects (median age, 5.3 years; IQR, 2.6-6.4 years), with no serious adverse events attributable to the study drug. The areas under the curve for atorvastatin and its metabolite were larger in the study subjects compared with those reported in adults, suggesting a slower rate of metabolism in children. The 24-OHC levels were similar between the atorvastatin-treated subjects and matched controls.

CONCLUSIONS

Atorvastatin was safe and well tolerated in our cohort of children with acute Kawasaki disease and CAA. A Phase III efficacy trial is warranted in this patient population, which may benefit from the known anti-inflammatory and immunomodulatory effects of this drug.

TNF-α blockers for the treatment of Kawasaki disease in children

BACKGROUND

Kawasaki disease (KD) is an acute inflammatory vasculitis (inflammation of the blood vessels) that mainly affects children between six months and five years of age. The vasculitis primarily impacts medium-sized blood vessels, especially in the coronary arteries. In most children, intravenous immunoglobulin (IVIG) and aspirin therapy rapidly reduce inflammatory markers, fever, and other clinical symptoms. However, approximately 15% to 20% of children receiving the initial IVIG infusion show persistent or recurrent fever and are classified as IVIG-resistant. Tumor necrosis factor-alpha (TNF-α) is an inflammatory cytokine that plays an important role in host defence against infections and in immune responses. Several studies have established that blocking TNF-α is critical for obtaining anti-inflammatory effects in children with KD, thus, there is a need to identify benefits and risks of TNF-α blockers for the treatment of KD.

OBJECTIVES

To evaluate the efficacy and safety of using TNF-α blockers (i.e. infliximab and etanercept) to treat children with Kawasaki disease.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases, the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials register to 19 September 2018. We also undertook reference checking of grey literature.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared TNF-α blockers (i.e. infliximab and etanercept) to placebo or other drugs (including retreatment with IVIG) in children with KD, reported in abstract or full-text.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the study selection criteria, assessed risk of bias and extracted data. When necessary, we contacted study authors for additional information. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included five trials from 14 reports, with a total of 494 participants. All included trials were individual RCTs that examined the effect of TNF-α blockers for KD.Five trials (with 494 participants) reported the incidence of treatment resistance. TNF-α blockers reduced the incidence of treatment resistance (TNF-α blocker intervention group 30/237, control group 58/257; risk ratio (RR) 0.57, 95% confidence interval (CI) 0.38 to 0.86; low-certainty evidence).Four trials reported the incidence of coronary artery abnormalities (CAAs). Three trials (with 270 participants) contributed data to the meta-analysis, since we could not get the data needed for the analysis from the fourth trial. There was no clear difference between groups in the incidence of CAAs (TNF-α blocker intervention group 8/125, control group 9/145; RR 1.18, 95% CI 0.45 to 3.12; low-certainty evidence).Three trials with 250 participants reported the adverse effect 'infusion reactions' after treatment initiation. The TNF-α blocker intervention decreased infusion reactions (TNF-α blocker intervention group 0/126, control group 15/124; RR 0.06, 95% CI 0.01 to 0.45; low-certainty evidence).Two trials with 227 participants reported the adverse effect 'infections' after treatment initiation. There was no clear difference between groups (TNF-α blocker intervention group 7/114, control group 10/113; RR 0.68, 95% CI 0.33 to 1.37; low-certainty evidence).One trial (with 31 participants) reported the adverse effect 'cutaneous reactions' (rash and contact dermatitis). There was no clear difference between the groups for incidence of rash (TNF-α blocker intervention group 2/16, control group 0/15; RR 4.71, 95% CI 0.24 to 90.69; very low-certainty evidence) or for incidence of contact dermatitis (TNF-α blocker intervention group 1/16, control group 3/15; RR 0.31, 95% CI 0.04 to 2.68; very low-certainty evidence).No trials reported other adverse effects such as injection site reactions, neutropenia, infections, demyelinating disease, heart failure, malignancy, and induction of autoimmunity.

AUTHORS' CONCLUSIONS

We found a limited number of RCTs examining the effect of TNF-α blockers for KD. In summary, low-certainty evidence indicates that TNF-α blockers have beneficial effects on treatment resistance and the adverse effect 'infusion reaction' after treatment initiation for KD when compared with no treatment or additional treatment with IVIG. Further research will add to the evidence base. Due to the small number of underpowered trials contributing to the analyses, the results presented should be treated with caution. Further large high quality trials with timing and type of TNF-α blockers used are needed to determine the effects of TNF-α blockers for KD.

Kawasaki Disease: The Role of Immune Complexes Revisited

Kawasaki disease (KD) is an inflammatory disease in children associated with vasculitis affecting predominantly the coronary arteries and is now the most common cause of acquired heart disease in children in developed countries. The etiology of KD is unknown but epidemiological studies implicate an infectious agent or toxin, which causes disease in genetically predisposed individuals. The presence of immune complexes (ICs) in the serum of children with KD was established in numerous studies during the 1970s and 80s. More recent genetic studies have identified variation in Fcγ receptors and genes controlling immunoglobulin production associated with KD. In this review we link the genetic findings and IC studies and suggest a key role for their interaction in pathophysiology of the disease.

Tratamiento farmacológico de la enfermedad de Kawasaki

Introducción. La enfermedad de Kawasaki corresponde a una vasculitis sistémica de origen desconocido y su principal complicación es la formación de aneurismas coronarios.Objetivo. Realizar una revisión actualizada de la literatura acerca del tratamiento farmacológico de la enfermedad de Kawasaki.Materiales y métodos. Se realizó una búsqueda estructurada de la literatura en las bases de datos ProQuest, EBSCO, ScienceDirect, PubMed, LILACS, Embase, Trip Database, SciELO y Cochrane Library con los términos “Kawasaki disease AND therapeutics”, “Kawasaki disease AND treatment” y “Mucocutaneous Lymph Node Syndrome AND therapeutics”, en inglés y con sus equivalentes en español.Resultados. Se encontraron 51 artículos con información relevante para el desarrollo de la presente revisión.Conclusiones. El diagnóstico y el tratamiento oportuno de la enfermedad de Kawasaki son fundamentales para la prevención de las complicaciones coronarias. El tratamiento incluye la terapia combinada de ácido acetilsalicílico más inmunoglobulina G, la cual reduce la incidencia de aneurismas coronarios. Por su parte, las terapias con corticosteroides y otros fármacos inmunosupresores son alternativas utilizadas en el tratamiento de la enfermedad de Kawasaki resistente a inmunoglobulina.

How Should We Classify Kawasaki Disease?

The exact classification of Kawasaki disease (KD) has been debated. Infectious disease specialists have claimed it as an infection with a classic immune responses to an as yet unidentified pathogen that localizes to the coronary arteries. Others have favored an autoreactive hypothesis that KD is triggered by an antigen that shares homology with structures in the vascular wall, and molecular mimicry resulting in an immune response directed to that tissue. Rheumatologists have classified it as a systemic vasculitis, while some immunologists have stressed the robust nature of the innate immune response that causes both systemic inflammation as well as damage to the coronary arterial wall and questioned whether KD falls within the spectrum of autoinflammatory diseases. This review will describe the evidences available up to now regarding these hypotheses.

Intravenous Immunoglobulin Gamma (IVIG) versus IVIG Plus Infliximab in Young Children with Kawasaki Disease

Background

Kawasaki disease (KD) is a serious disease characterized by systemic lesions of the skin and mucous membranes, as well as lymphomas and vascular inflammation. KD threatens the health and lives of children, especially young ones. Here, we compared the therapeutic effects of single intravenous immunoglobulin gamma (IVIG) vs. a combination of IVIG and infliximab in young children with Kawasaki disease (KD).

Material/Methods

A total of 154 children with KD, younger than 5 years old, were enrolled in the study from January 2013 to January 2017. The patients were randomly divided into an IVIG group and a combination of IVIG and infliximab treatment group. After systematic treatments, the therapeutic indicators of the 2 groups were compared. During the treatment process, body temperature and other important inflammatory indicators, including C-reactive protein (CRP), white blood cell count (WBC), and tumor necrosis factor alpha (TNF-α), were monitored in the first 4 days.

Results

There were fewer refractory KD patients in the combined treatment group than in the IVIG group (4 vs. 14, p<0.001). KD patients in the combined treatment group had better outcomes with shorter fever durations and hospital stays, as well as less coronary artery dilation. However, there was no obvious differences in the incidence rate of coronary artery aneurysms between the 2 groups (p>0.05). Costs of administration were similar between groups (p>0.05). Body temperature, CRP, WBC, and TNF-α in the combined therapy group all showed an earlier drop than in the IVIG group, indicating a more effective anti-inflammation effect.

Conclusion

The introduction of IVIG combined with infliximab in the treatment of young children with KD has more advantages than single IVIG therapy and can be considered as a preferred treatment for KD. However, it would be necessary to further investigate whether there is a significant difference in aneurysm frequency and long-term outcome between these 2 strategies among a larger number of patients.

Infliximab regulates monocytes and regulatory T cells in Kawasaki disease

BACKGROUND

The effect of infliximab (IFX) on immune cells has not been fully reported in Kawasaki disease (KD). To investigate the mechanism of IFX in KD, we examined changes in the abundance of CD14⁺ CD16⁺ activated monocytes, regulatory T cells (T_reg ) cells, and T-helper type 17 (Th17) cells following treatment with IFX.

METHODS

We collected peripheral blood from patients with i.v. immunoglobulin (IVIG)-resistant KD and analyzed absolute CD14⁺ CD16⁺ monocyte, T_reg (CD4⁺ CD25⁺ FOXP3⁺ ) and Th17 cell (CD4⁺ IL-17A⁺ ) counts on flow cytometry. We also measured changes in serum soluble interleukin (IL)-2 receptor (IL-2R), IL-6, and tumor necrosis factor (TNF)-α on enzyme-linked immunosorbent assay.

RESULTS

T_reg cells and Th17 cells significantly increased after IFX treatment compared with baseline (126 ± 85 cells/μL vs 62 ± 53 cells/μL, P < 0.01; 100 ± 111 cells/μL vs 28 ± 27 cells/μL, P < 0.05, respectively). In contrast, in a subgroup of patients with CD14⁺ CD16⁺ monocytes above the normal range before IFX, the CD14⁺ CD16⁺ monocytes significantly decreased following IFX treatment (72 ± 51 cells/μL vs 242 ± 156 cells/μL, P < 0.05).. Serum TNF-α did not change, but soluble IL-2R and IL-6 decreased after IFX treatment.

CONCLUSION

IFX could downregulate activated monocytes and upregulate T_reg cells towards the normal range. IFX treatment thus contributes to the process of attenuating inflammation in KD.

Effect and Safety of TNF Inhibitors in Immunoglobulin-Resistant Kawasaki Disease: a Meta-analysis

Previous studies showed that tumor necrosis factor (TNF) inhibitors might decrease the rate of coronary artery abnormalities in pediatrics with intravenous immunoglobulin (IVIG)-resistant Kawasaki disease (KD). Therefore, we aimed to evaluate the effect and safety of TNF inhibitors in IVIG-resistant KD. We undertook a meta-analysis of clinical trials identified in systematic searches of PubMed, EMBASE, Cochrane Database, and Google scholar through May 2016. Five studies were included. Overall, rate of coronary artery aneurysm was comparable between groups (relative risk (RR), 1.05; 95 % confidence interval (95 % CI), 0.60 to 1.81; P = 0.87). No significant differences were recorded between groups in coronary artery Z scores (standardized mean difference (SMD), 0.27; 95 % CI, -0.30 to 0.85; P = 0.35). Meanwhile, TNF inhibitors were not associated with a significant decreased risk of treatment resistance compared with IVIG treatment (RR, 0.65; 95 % CI, 0.37 to 0.15; P = 0.14). However, days of fever was significantly reduced in the TNF inhibitor group (SMD, -0.66; 95 % CI, -0.90 to -0.41; P < 0.001). Additionally, risk of serious adverse events was similar between groups. Therefore, TNF inhibitors could shorten the duration of fever in IVIG-resistant KD. However, TNF inhibitors appear to have no cardioprotective effect in patients with IVIG-resistant KD.

Pediatric tolerogenic DCs expressing CD4 and immunoglobulin-like transcript receptor (ILT)-4 secrete IL-10 in response to Fc and adenosine

We characterized a novel population of tolerogenic myeloid dendritic cells (tmDCs) defined as CD11c⁺ CD11b⁺ CD14⁺ CD4⁺ and immunoglobulin-like transcript receptor (ILT)-4⁺ that are significantly more abundant in the circulation of infants and young children than in adults. TmDCs secrete the immunosuppressive lymphokine interleukin (IL)-10 when stimulated with the heavy constant region of immunoglobulins (Fc) and express high levels of the adenosine A_2A receptor (A_2A R), which, when activated by adenosine, inhibits the release of pro-inflammatory cytokines from most immune cells. Here we show that stimulation of the A_2A R on tmDCs by regadenoson or N-ethylcarboxamidoadenosine (NECA) rapidly increases cyclic AMP accumulation and enhances IL-10 production under Fc stimulatory conditions. In co-culture experiments, tmDCs inhibit the differentiation of naïve T cells to a pro-inflammatory phenotype. In conclusion, although DCs are classically viewed as antigen presenting cells that activate T cells, we show an independent role of tmDCs in pediatric immune regulation that may be important for suppressing T cell responses to neoantigens in infants and young children.

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.

The serum concentration of soluble interleukin-2 receptor in patients with Kawasaki disease

Kawasaki disease is a febrile disease of childhood that is associated with increased inflammatory cytokines and immunoregulatory abnormalities. While the serum concentrations of soluble IL-2 receptor can change under such pathologies, the relevance of the soluble IL-2 receptor concentration in patients with Kawasaki disease has not been specified. We aimed to summarize the existing studies that reported the soluble IL-2 receptor concentrations in patients with Kawasaki disease. Original articles that were published up to July 2016 were collected using a PubMed/Medline-based search engine. A total of nine articles that reported the serum soluble IL-2 receptor concentrations in acute-phase Kawasaki disease were eligible. All of the articles described a high soluble IL-2 receptor concentration in patients with Kawasaki disease relative to the level of controls or the reference range. Two of five articles on patients with coronary artery aneurysms described a significantly higher soluble IL-2 receptor concentration in patients with coronary artery aneurysms than patients without. Two articles on patients with intravenous immunoglobulin therapy described a significant decrease of the soluble IL-2 receptor concentration after the therapy. Accordingly, the serum soluble IL-2 receptor can be a potent marker of disease activity and therapeutic effects in patients with Kawasaki disease; further studies are thus warranted for its use in the clinical setting.

Kawasaki Disease

Kawasaki disease is an acute, self-limited vasculitis of unknown etiology that occurs predominantly in infants and children. If not treated early with high-dose intravenous immunoglobulin, 1 in 5 children develop coronary artery aneurysms; this risk is reduced 5-fold if intravenous immunoglobulin is administered within 10 days of fever onset. Coronary artery aneurysms evolve dynamically over time, usually reaching a peak dimension by 6 weeks after illness onset. Almost all the morbidity and mortality occur in patients with giant aneurysms. Risk of myocardial infarction from coronary artery thrombosis is greatest in the first 2 years after illness onset. However, stenosis and occlusion progress over years. Indeed, Kawasaki disease is no longer a rare cause of acute coronary syndrome presenting in young adults. Both coronary artery bypass surgery and percutaneous intervention have been used to treat Kawasaki disease patients who develop myocardial ischemia as a consequence of coronary artery aneurysms and stenosis.

Adjunctive therapies for Kawasaki disease

Kawasaki disease (KD) is the most common cause of acquired heart disease in children in developed countries.(1,2) The primary goal of treatment is to prevent coronary artery aneurysms (CAA). Between 10 and 20% of KD patients are resistant to treatment with intravenous immunoglobulin (IVIG) and have an almost nine-fold increased risk of developing CAA.(3) In addition, approximately 80-90% of patients who go on to develop CAA have abnormal coronary artery dimensions on their first echocardiogram and can therefore be identified as high-risk patients. These two subsets of KD patients are candidates for adjunctive therapy, in addition to IVIG. Understanding the mechanism of action of IVIG may provide insight into IVIG resistance and guidance for choosing adjunctive therapies in KD. Therapeutic options in the treatment of refractory KD and patients with early CAA include additional IVIG, glucocorticoids, tumor necrosis factor inhibitors, calcineurin inhibitors and interleukin-1 (IL-1) blockers.(3-10) Animal studies suggest that the anti-inflammatory properties of statins may also be beneficial in blocking CAA progression.(6) It is unlikely that these therapies will be studied in large, randomized controlled trials in the future due to required sample size and funding constraints. Thus, data from the research laboratory may be helpful in guiding selection of the most promising adjunctive therapies.

The immunomodulatory effects of intravenous immunoglobulin therapy in Kawasaki disease

The introduction of intravenous immunoglobulin (IVIG) for modulation of inflammation in acute Kawasaki disease was a great therapeutic triumph. However, three decades later, the mechanisms underlying immune regulation by IVIG are only beginning to be revealed. Stimulation of an immature myeloid population of dendritic cells that secretes IL-10 and the elucidation of Fc-specific natural regulatory T cells provide insights into the mechanisms of IVIG. Other potential mechanisms include provision of agent-specific neutralizing antibody, anti-idiotype and anti-cytokine antibodies, blockade of activating Fcγ receptors and stimulation of the inhibitory FcγRIIb receptor. New initiatives must seek to understand the mechanisms of IVIG in order to replace it one day with more affordable and more targeted therapies.

Induction of Regulatory T Cells by Intravenous Immunoglobulin: A Bridge between Adaptive and Innate Immunity

Intravenous immunoglobulin (IVIg) is a polyclonal immunoglobulin G preparation with potent immunomodulatory properties. The mode of action of IVIg has been investigated in multiple disease states, with various mechanisms described to account for its benefits. Recent data indicate that IVIg increases both the number and the suppressive capacity of regulatory T cells, a subpopulation of T cells that are essential for immune homeostasis. IVIg alters dendritic cell function, cytokine and chemokine networks, and T lymphocytes, leading to development of regulatory T cells. The ability of IVIg to influence Treg induction has been shown both in animal models and in human diseases. In this review, we discuss data on the potential mechanisms contributing to the interaction between IVIg and the regulatory T-cell compartment.

Fine specificities of natural regulatory T cells after IVIG therapy in patients with Kawasaki disease

The activation of natural regulatory T cells (nTreg) recognizing the heavy constant region (Fc) of IgG is an important mechanism of action of intravenous immunoglobulin (IVIG) therapy in Kawasaki disease (KD). Lack of circulating Fc-specific nTreg in the sub-acute phase of KD is correlated with the development of coronary artery abnormalities (CAA). Here, we characterize the fine specificity of nTreg in sub-acute (2- to 8-week post-IVIG) and convalescent (1- to 10-year post-IVIG) KD subjects by testing the immunogenicity of 64 peptides, 15 amino acids in length with a 10 amino acid-overlap spanning the entire Fc protein. About 12 Fc peptides (6 pools of 2 consecutive peptides) were recognized by nTreg in the cohorts studied, including two patients with CAA. To test whether IVIG expands the same nTreg populations that maintain vascular homeostasis in healthy subjects, we compared these results with results obtained in healthy adult controls. Similar nTreg fine specificities were observed in KD patients after IVIG and in healthy donors. These results suggest that T cell fitness rather than T cell clonal deletion or anergy is responsible for the lack of Fc-specific nTreg in KD patients who develop CAA. Furthermore, we found that adolescents and adults who had KD during childhood without developing CAA did not respond to the Fc protein in vitro, suggesting that the nTreg response induced by IVIG in KD patients is short-lived. Our results support the concept that peptide epitopes may be a viable therapeutic approach to expand Fc-specific nTreg and more effectively prevent CAA in KD patients.

Intravascular immunity as a key to systemic vasculitis: a work in progress, gaining momentum

Vascular inflammation contributes to the defence against invading microbes and to the repair of injured tissues. In most cases it resolves before becoming apparent. Vasculitis comprises heterogeneous clinical entities that are characterized by the persistence of vascular inflammation after it has served its homeostatic function. Most underlying mechanisms have so far remained elusive. Intravascular immunity refers to the surveillance of the vasculature by leucocytes that sense microbial or sterile threats to vessel integrity and initiate protective responses that entail most events that determine the clinical manifestations of vasculitis, such as end-organ ischaemia, neutrophil extracellular traps generation and thrombosis, leucocyte extravasation and degranulation. Understanding how the resolution of vascular inflammation goes awry in patients with systemic vasculitis will facilitate the identification of novel pharmacological targets and bring us a step closer in each patient to the selection of more effective and less toxic treatments.

Fragments of truth: T-cell targets of polyclonal immunoglobulins in autoimmune diseases

The expanding therapeutic use of high-dose intravenous immunoglobulin (IVIg) in autoimmune diseases has raised important practical and conceptual issues over the last few years. These have prompted a number of research efforts aimed at characterizing aspects of the mechanism of action of current IVIg preparations, which might lead to the development of standardized, more cost-effective agents. Although polyclonal IgG in these preparations are mostly thought to act via direct interference with disease-specific, pathogenic autoantibodies, evidence from clinical and experimental work points to the involvement of crucial checkpoints upstream of self-reactive B-cell activation and autoantibody production. Reviewed herein are the results of the most recent studies documenting the crucial role of regulatory T cells (Treg) in the immunomodulatory activity of IVIg, and the molecular mechanisms mediating the effect of specific IgG fragments and glycoforms on Treg activity and the ensuing downregulation of T-cell effector responses of different sign and magnitude. Further progress in this area of translational research may lead to the development of innovative strategies aimed at restoring tolerance in autoimmune diseases.

Infliximab for intensification of primary therapy for Kawasaki disease: a phase 3 randomised, double-blind, placebo-controlled trial

BACKGROUND

Kawasaki disease, the most common cause of acquired heart disease in developed countries, is a self-limited vasculitis that is treated with high doses of intravenous immunoglobulin. Resistance to intravenous immunoglobulin in Kawasaki disease increases the risk of coronary artery aneurysms. We assessed whether the addition of infliximab to standard therapy (intravenous immunoglobulin and aspirin) in acute Kawasaki disease reduces the rate of treatment resistance.

METHODS

We undertook a phase 3, randomised, double-blind, placebo-controlled trial in two children's hospitals in the USA to assess the addition of infliximab (5 mg per kg) to standard therapy. Eligible participants were children aged 4 weeks-17 years who had a fever (temperature ≥38·0°C) for 3-10 days and met American Heart Association criteria for Kawasaki disease. Participants were randomly allocated in 1:1 ratio to two treatment groups: infliximab 5 mg/kg at 1 mg/mL intravenously over 2 h or placebo (normal saline 5 mL/kg, administered intravenously). Randomisation was based on a randomly permuted block design (block sizes 2 and 4), stratified by age, sex, and centre. Patients, treating physicians and staff, study team members, and echocardiographers were all masked to treament assignment. The primary outcome was the difference between the groups in treatment resistance defined as a temperature of 38·0°C or higher at 36 h to 7 days after completion of the infusion of intravenous immunoglobulin. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, NCT00760435.

FINDINGS

196 patients were enrolled and randomised: 98 to the infliximab group and 98 to placebo. One patient in the placebo group was withdrawn from the study because of hypotension before receiving treatment. Treatment resistance rate did not differ significantly (11 [11·2%] for infliximab and 11 [11·3%] for placebo; p=0·81). Compared with the placebo group, participants given infliximab had fewer days of fever (median 1 day for infliximab vs 2 days for placebo; p<0·0001). At week 2, infliximab-treated patients had greater mean reductions in erythrocyte sedimentation rate (p=0·009) and a two-fold greater decrease in Z score of the left anterior descending artery (p=0·045) than did those in the placebo group, but this difference was not significant at week 5. Participants in the infliximab group had a greater mean reduction in C-reactive protein concentration (p=0·0003) and in absolute neutrophil count (p=0·024) at 24 h after treatment than did those given placebo, but by week 2 this difference was not significant. At week 5, none of the laboratory values differed significantly compared with baseline. No significant differences were recorded between the two groups at any timepoint in proximal right coronary artery Z scores, age-adjusted haemoglobin values, duration of hospital stay, or any other laboratory markers of inflammation measured. No reactions to intravenous immunoglobulin infusion occurred in patients treated with infliximab compared with 13 (13·4%) patients given placebo (p<0·0001). No serious adverse events were directly attributable to infliximab infusion.

INTERPRETATION

The addition of infliximab to primary treatment in acute Kawasaki disease did not reduce treatment resistance. However, it was safe and well tolerated and reduced fever duration, some markers of inflammation, left anterior descending coronary artery Z score, and intravenous immunoglobulin reaction rates.

FUNDING

US Food and Drug Administration, Robert Wood Johnson Foundation, and Janssen Biotech.

Specificity of regulatory T cells that modulate vascular inflammation

Intravenous immunoglobulin therapy (IVIG) is the treatment of choice for many immune-mediated diseases, yet its mechanisms of action are incompletely elucidated. We investigated the possibility that IVIG played a direct role in the expansion of regulatory T cells (Treg) that recognize the heavy chain constant region of immunoglobulin G (Fc) as a mechanism for the recovery of Kawasaki disease (KD), a T cell mediated pediatric vasculitis of the coronary arteries. We successfully generated Fc-specific Treg clones from sub-acute KD subjects that did not develop arterial complications after IVIG and defined an unusual functional phenotype: Fc-specific Treg secrete IL-10 and small amounts of IL-4 but not TGF-β. Antigen presentation studies demonstrated that these Treg clones can be activated by autologous B cells that express IgG on their cell surface in the absence of exogenous Fc. The IgG molecule has to be canonically processed and presented by autologous MHC molecules to be recognized by Treg. In support of the importance of this novel Treg population in downsizing vascular inflammation, KD patients with dilated coronary arteries or aneurysms despite IVIG treatment failed to expand Fc-specific Treg. Our results point to a specificity of a previously un-described Treg population for the clinical benefit provided by IVIG therapy in children.