Clinical characteristics of hemophagocytic lymphohistiocytosis following Kawasaki disease: differentiation from recurrent Kawasaki disease

The landscape of hot topics and research frontiers in Kawasaki disease: Scientometric analysis

Purpose

Kawasaki disease(KD) is a vascular inflammatory disease that was first identified in 1967. Numerous studies have been conducted on KD and have yielded valuable recent insights. This current bibliometric analysis aimed to determine the intellectual landscape of research interest in KD.

Methods

Publications were collected from the Web of Science Core Collection. Bibliometric tools such as CiteSpace and VOSviewer were utilized to analyze the research focus, emerging trends, frontiers, and hot topics in this specific field.

Results

A total of 6122 articles on KD were retrieved. Pediatric Cardiology, Pediatrics International, and Pediatric Infections Disease Journal were the three most productive journals reporting KD development. The University of California San Diego was the most productive institution, with 230 publications. The USA was the most productive country, with 1661 articles in KD. SARS-CoV-2, diagnostic serum biomarkers, and risk factor prediction models for coronary arterial lesions and subtypes of KD are popular topics in KD research. Factors that induce smooth muscle cell transition to myofibroblastic cell, potentially halting the subacute/chronic vasculitis process and endothelial dysfunction in macrophage activation syndrome associated with KD were the frontiers in the study of KD.

Conclusion

KD has attracted widespread attention worldwide that has continued to increase since 1974. The most productive institution and country are the University of California San Diego and the USA, respectively. SARS-CoV-2, serum biomarkers, and prediction models are hot topics in this field.

The History of Macrophage Activation Syndrome in Autoimmune Diseases

In 1979, it became recognized in the literature that what we call hemophagocytic lymphohistiocytosis (HLH) was a nonmalignant disease of histiocytes. Subsequently a familial form and a secondary form of HLH were differentiated. When HLH is secondary to an autoimmune disease, rheumatologists refer to this entity as macrophage activation syndrome (MAS) to differentiate it from HLH itself. Although the first cases of MAS likely appeared in the literature in the 1970s, it was not until 1985 that the term activated macrophages was used to describe patients with systemic juvenile idiopathic arthritis (sJIA) complicated by MAS and the term macrophage activation syndrome first appeared in the title of a paper in 1993.MAS is one of the many types of secondary HLH and should not be confused with primary HLH. Experience has taught that MAS secondary to different autoimmune diseases is not equal. In the 30 years since initial description in patients with sJIA, the clinical spectrum, diseases associated with MAS, therapy, and understanding the pathogenesis have all made significant gains. The diagnostic/classification criteria for MAS secondary to sJIA, SLE, RA, and KD differ based on the different laboratory abnormalities associated with each (Ahn et al., J Rheumatol 44:996-1003, 2017; Han et al., Ann Rheum Dis 75:e44, 2016; Ravelli et al., Ann Rheum Dis 75:481-489, 2016; Borgia et al., Arthritis Rheumatol 70:616-624, 2018). These examples include the thrombocytosis associated with sJIA, a chronic generalized activation of the immune system, leading to elevations of fibrinogen and sIL-2R, low platelet count associated with SLE, and more acute inflammation associated with KD. Therefore, individual diagnostic criteria are required, and they all differ from the diagnostic criteria for HLH, which are based on a previously non-activated immune system (Ahn et al., J Rheumatol 44:996-1003, 2017; Han et al., Ann Rheum Dis 75:e44, 2016; Ravelli et al., Ann Rheum Dis 75:481-489, 2016; Borgia et al., Arthritis Rheumatol 70:616-624, 2018; Henter et al., Pediatr Blood Cancer 48:124-131, 2007). This helps to explain why the HLH diagnostic criteria do not perform well in MAS.The initial treatment remains high-dose steroids and IVIG followed by the use of a calcineurin inhibitor for resistant cases. IVIG can be used if there is a concern about malignancy to wait for appropriate investigations or with steroids. Interluekin-1 inhibition is now the next therapy if there is a failure to respond to steroids and calcineurin inhibitors. Advances in understanding the mechanisms leading to MAS, which has been greatly aided by the use of mouse models of MAS and advances in genome sequencing, offer a bright future for more specific therapies. More recent therapies are directed to specific cytokines involved in the pathogenesis of MAS and can lead to decreases in the morbidity and mortality associated with MAS. These include therapies directed to inhibiting the JAK/STAT pathway and/or specific cytokines, interleukin-18 and gamma interferon, which are currently being studied in MAS. These more specific therapies may obviate the need for nonspecific immunosuppressive therapies including high-dose prolonged steroids, calcineurin inhibitors, and etoposide.

Kawasaki Disease-Associated Cytokine Storm Syndrome

Kawasaki disease (KD) is a hyperinflammatory syndrome manifesting as an acute systemic vasculitis characterized by fever, nonsuppurative conjunctival injection, rash, oral mucositis, extremity changes, and cervical lymphadenopathy. KD predominantly affects young children and shares clinical features and immunobiology with other hyperinflammation syndromes including systemic juvenile idiopathic arthritis (sJIA) and multisystem inflammatory syndrome in children (MIS-C). Cytokine storm syndrome (CSS) is an acute complication in ~2% of KD patients; however, the incidence is likely underestimated as many clinical and laboratory features of both diseases overlap. CSS should be entertained when a child with KD is unresponsive to IVIG therapy with recalcitrant fever. Early recognition and prompt institution of immunomodulatory treatment can substantially reduce the mortality and morbidity of CSS in KD. Given the known pathogenetic role of IL-1β in both syndromes, the early use of IL-1 blockers in refractory KD with CSS deserves consideration.

Genetics of Acquired Cytokine Storm Syndromes : Secondary HLH Genetics

Secondary hemophagocytic lymphohistiocytosis (sHLH) has historically been defined as a cytokine storm syndrome (CSS) occurring in the setting of triggers leading to strong and dysregulated immunological activation, without known genetic predilection. However, recent studies have suggested that existing underlying genetic factors may synergize with particular diseases and/or environmental triggers (including infection, autoimmune/autoinflammatory disorder, certain biologic therapies, or malignant transformation), leading to sHLH. With the recent advances in genetic testing technology, more patients are examined for genetic variations in primary HLH (pHLH)-associated genes, including through whole exome and whole genome sequencing. This expanding genetic and genomic evidence has revealed HLH as a more complex phenomenon, resulting from specific immune challenges in patients with a susceptible genetic background. Rather than a simple, binary definition of pHLH and sHLH, HLH represents a spectrum of diseases, from a severe complication of common infections (EBV, influenza) to early onset familial diseases that can only be cured by transplantation.

Platelet and ferritin as early predictive factors for the development of macrophage activation syndrome in children with Kawasaki disease: A retrospective case-control study

OBJECTIVE

To investigate the early predictive factors for Kawasaki disease complicated with macrophage activation syndrome (KD-MAS).

METHODS

We performed a retrospective case-control study in children with KD from August 2017 to August 2022, involving 28 cases with KD-MAS and 112 cases not developing KD-MAS. Based on the univariate analysis, binary logistic regression was used to identify the early predictive factors for KD-MAS development, and the receiver operating characteristic curve (ROC) analysis was carried out to obtain the optimal cut-off value.

RESULTS

Two predictive factors were associated with the development of KD-MAS, which were PLT (OR = 1.013, 95%CI, 1.001-1.026), and serum ferritin (OR = 0.991, 95%CI, 0.982-0.999). The cut-off value of PLT was 110 × 10⁹/L, and the cut-off value of serum ferritin was 548.4 ng/ml.

CONCLUSION

Children with KD who had a PLT count under 110 × 10⁹/L, and a serum ferritin level over 548.4 ng/ml are more likely to develop KD-MAS.

Macrophage activation syndrome in children with Kawasaki disease: an experience from a tertiary care hospital in northwest India

OBJECTIVES

To carry out a review of clinical characteristics, laboratory profiles, management and outcomes of patients with Kawasaki disease (KD) and macrophage activation syndrome (MAS).

METHODS

Medical records of patients treated for KD and MAS between January 1994 and December 2019 were reviewed. Patient demographics, clinical signs, laboratory values, coronary artery abnormalities, treatments and outcomes of patients with KD and MAS were recorded. We also performed a review published studies on the subject.

RESULTS

Of the 950 cases with KD, 12 (1.3%; 10 boys, 2 girls) were diagnosed with MAS. The median age at diagnosis was 4 years (range 9 months-7.5 years). The median interval between onset of fever and diagnosis of KD was 11 days (range 6-30). Thrombocytopenia was seen in 11 patients. The median pro-brain natriuretic peptide value was 2101 pg/ml (range 164-75 911). Coronary artery abnormalities were seen in 5 (41.7%) patients; 2 had dilatation of the left main coronary artery (LMCA), 1 had dilatation of both the LMCA and right coronary artery (RCA), 1 had dilatation of the RCA and 1 had bright coronary arteries. All patients received IVIG as first-line therapy for KD. MAS was treated with i.v. methylprednisolone pulses followed by tapering doses of oral prednisolone. Additional therapy included i.v. infliximab (n = 4), second-dose IVIG (n = 1) and oral ciclosporin (n = 1).

CONCLUSION

MAS is an unusual and underrecognized complication of KD. In our cohort of 950 patients with KD, 1.3% had developed MAS. KD with MAS is associated with an increased propensity towards development of coronary artery abnormalities.

Kawasaki Disease: A Systematic Review and Meta-Analysis of Benefits and Harms of Common Treatments

Objective

Kawasaki disease (KD) is a self‐limited vasculitis affecting medium‐sized vessels with a predilection for the coronary arteries. Although treatment reduces the likelihood of developing of coronary artery aneurysms, 5% of patients still develop aneurysms despite treatment, making KD the leading cause of acquired heart disease in children in the United States. Consequently, there is a great deal of interest in optimizing treatment regimens, particularly for higher‐risk patients, to decrease morbidity. The aim of this systematic review is to support the development of the American College of Rheumatology/Vasculitis Foundation for the diagnosis and management of KD, focusing on the more complex scenarios in which rheumatologists may become involved, such as high‐risk and refractory disease.

Methods

Eighty‐nine articles were considered for full review in this systematic literature review to address 16 Population, Intervention, Comparison, and Outcome questions related to KD. Data were abstracted in hierarchical fashion. Randomized control trials (RCTs) were considered first; if none were identified or if they contained insufficient information, comparative observational studies were then viewed, followed by single‐arm observational studies/single arms from comparative studies. Only observational studies with more than 10 subjects with vasculitis were included.

Results

Eight RCTs and 28 observational studies that addressed the questions were identified. Two questions were addressed by RCTs, seven questions had at least some comparative observational studies, three questions were only addressed by single‐arm data, and four questions had no relevant studies.

Conclusion

This systematic review evaluates the benefits and harms of treatments for KD beyond first‐line therapy.

Importance of Serum Ferritin Level for Early Diagnosis and Differentiation in Patients with Kawasaki Disease with Macrophage Activation Syndrome

We aimed to evaluate the utility of the serum ferritin level as an early screening test of Kawasaki disease with macrophage activation syndrome (KD-MAS). We analyzed the serum ferritin levels on the first day of admission and the clinical progress of patients diagnosed with complete or incomplete KD. Of the 158 patients, 5 were diagnosed with KD-MAS. Conjunctival injection was significantly more frequent in KD group (p = 0.035), although there were no significant differences in other clinical features. On the first day of admission, the serum ferritin level in the KD-MAS group was >500 ng/mL, which was higher than that in the KD group (p = 0.001). In the KD-MAS group, total bilirubin, triglyceride, and lactate dehydrogenase (LDH) were significantly higher, and erythrocyte sedimentation rate (ESR), total protein, albumin, and fibrinogen were significantly lower than the KD group (p < 0.05). Four patients were diagnosed with MAS within 7 days after admission, and 4 (80%) patients with KD-MAS survived. In conclusion, carrying out an early ferritin screening test is important in patients with principal clinical features that may suspect KD. We propose to include ferritin level in the primary laboratory test to differentiate between KD with and without MAS early.

Severe Recurrent Fever Episodes With Clinical Diagnosis of Hemophagocytic Lymphohistiocytosis, Incomplete Kawasaki Disease and Systemic-Onset Juvenile Idiopathic Arthritis: A Case Report and Literature Review

The pathogeneses of recurrent fever are quite complicated when excluding repeated infections. Recurrent fever is a common symptom for autoinflammatory diseases, relapse of Systemic-onset juvenile idiopathic arthritis (SoJIA) and recurrent Kawasaki disease (KD). There are no specific diagnostic laboratory tests for the diseases. Some studies showed that KD was the precursor of hemophagocytic lymphohistiocytosis (HLH). Macrophage activation syndrome (MAS) is another form of HLH in SoJIA. Cytokine disturbances are considered to be involved in the pathogenesis of the diseases. We describe a Chinese female toddler that developed three separate fever episodes with eventual diagnose of SoJIA within about 10 months. The first episode was diagnosed as IKD, immunoglobulin nonresponsive KD, and HLH. The second and third episodes were diagnosed as IKD and SoJIA, respectively. The fever was hard to be relieved by antipyretics, and the peak axillary temperature was above 40°C. For every fever episode, infections were excluded. For the first episode, trends over time of hemoglobin, platelets, fibrinogen, and triglycerides indicated HLH, which was finally diagnosed and treated according to the HLH-2004 protocol. For the second episode 6 months later, after excluding an HLH relapse and infections, IKD was finally diagnosed. Oral aspirin was administered, and the HLH treatment was ceased. The third episode occurred 3 months later, and SoJIA was finally diagnosed. For each episode, except for relative tests, we only tested for cytokines interleukin-1β, interleukin-6, and interferon-γ, due to limited laboratory test availability. These cytokines were elevated during remission and rose much higher in the fever phases. The case showed the difficulty to differentiating the recurrent fever in clinical practice. Surveillance of routine laboratory parameters over time might reveal a trend that indicates possible disease, even when parameter values do not meet diagnostic criteria. Changes in cytokine profiles are promising markers for differentiating recurrent fever diseases in future. An unknown immunological defect for the case may contribute to the recurrent immunological insults, and we are following up the recurrence of fever episode.

Kawasaki disease: guidelines of the Italian Society of Pediatrics, part I - definition, epidemiology, etiopathogenesis, clinical expression and management of the acute phase

The primary purpose of these practical guidelines related to Kawasaki disease (KD) is to contribute to prompt diagnosis and appropriate treatment on the basis of different specialists’ contributions in the field. A set of 40 recommendations is provided, divided in two parts: the first describes the definition of KD, its epidemiology, etiopathogenetic hints, presentation, clinical course and general management, including treatment of the acute phase, through specific 23 recommendations.

Their application is aimed at improving the rate of treatment with intravenous immunoglobulin and the overall potential development of coronary artery abnormalities in KD. Guidelines, however, should not be considered a norm that limits treatment options of pediatricians and practitioners, as treatment modalities other than those recommended may be required as a result of peculiar medical circumstances, patient’s condition, and disease severity or complications.

Kawasaki disease: guidelines of Italian Society of Pediatrics, part II - treatment of resistant forms and cardiovascular complications, follow-up, lifestyle and prevention of cardiovascular risks

This second part of practical Guidelines related to Kawasaki disease (KD) has the goal of contributing to prompt diagnosis and most appropriate treatment of KD resistant forms and cardiovascular complications, including non-pharmacologic treatments, follow-up, lifestyle and prevention of cardiovascular risks in the long-term through a set of 17 recommendations.Guidelines, however, should not be considered a norm that limits the treatment options of pediatricians and practitioners, as treatment modalities other than those recommended may be required as a result of peculiar medical circumstances, patient's condition, and disease severity or individual complications.

Differentiation between incomplete Kawasaki disease and secondary hemophagocytic lymphohistiocytosis following Kawasaki disease using N-terminal pro-brain natriuretic peptide

Purpose

Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome with many causes, including Kawasaki disease (KD). The purpose of this study was to identify the laboratory tests needed to easily differentiate KD with HLH from incomplete KD alone.

Methods

We performed a retrospective study on patients diagnosed with incomplete KD and incomplete KD with HLH (HLH-KD) between January 2012 and March 2015. We compared 8 secondary HLH patients who were first diagnosed with incomplete KD with all 247 incomplete KD diagnosed patients during the study period. The complete blood count, erythrocyte sedimentation rate, platelet count, and serum total protein, albumin, triglyceride, C-reactive protein, N-terminal pro-brain natriuretic peptide (NT-proBNP), and ferritin levels were compared. Clinical characteristics and echocardiography findings were also compared between the 2 groups.

Results

The total duration of fever was longer in the HLH-KD group than in the KD group. White blood cell and platelet counts were higher in the KD group. Alanine aminotransferase, ferritin, and coronary artery diameter were increased in the HLH-KD group compared with those in the KD group. The median of NT-proBNP was significantly higher in the HLH-KD group than in the KD group at 889.0 (interquartile range [IQR], 384.5-1792.0) pg/mL vs. 233.0 (IQR, 107.0-544.0) pg/mL.

Conclusion

The NT-proBNP level may be helpful in distinguishing incomplete KD from KD with HLH. The NT-proBNP level should be determined in KD patients with prolonged fever, in addition to the white blood cell count, platelet count, and ferritin level, to evaluate secondary HLH.

A Case of Hemophagocytic Lymphohistiocytosis and Kawasaki Disease: Concurrent or Overlapping Diagnoses?

Hemophagocytic lymphohistiocytosis (HLH) is not always suspected at the time of presentation. It is often mistaken for other diagnoses; complicated by the fact that it is often associated with an inciting event that has significant overlap. Kawasaki disease, along with other disorders, such as Ebstein Barr Virus infection, are conditions that may lead HLH. Our patient had a presentation that was consistent with Kawasaki disease on initial presentation, however subsequently met the diagnostic criteria of HLH. It provided an interesting discussion about diagnoses with clinical criteria and how the overlap can sometimes delay or complicate initial diagnosis.

Kawasaki Disease Complicated With Macrophage Activation Syndrome: A Systematic Review

Macrophage activation syndrome (MAS), also known as secondary hemophagocytic lymphohistiocytosis, is a rare and potentially fatal complication of Kawasaki disease (KD). We report 2 cases, performed a literature search, and analyze the characteristics of MAS associated with KD. A total of 69 patients were evaluated, 34 reported the date of the diagnosis of MAS and KD, 6% had a diagnosis of MAS before KD, 21% had a simultaneous presentation, and 73% had the diagnosis of MAS after KD. Different treatment approaches were observed with corticosteroids administered in 87%, cyclosporine in 49%, etoposide (VP-16) in 39%, and monoclonal anti-TNF in 6% of cases. Coronary abnormalities were especially high in this group of patients (46%) and 9 patients died (13%). The persistence of fever with splenomegaly, hyperferritinemia, thrombocytopenia, and elevated aspartate aminotransferase (AST) should prompt the consideration of MAS complicating KD.

Characteristics of children with Kawasaki disease requiring intensive care: 10 years' experience at a tertiary pediatric hospital

BACKGROUND/PURPOSE

Kawasaki disease (KD) is a febrile systemic vasculitis, and some patients may develop serious complications requiring intensive care. We aim to ascertain the clinical presentations and outcomes of these patients.

METHODS

From October 2004 to October 2014, children with KD who had stayed in the pediatric intensive care unit (ICU) for acute stage treatment were defined as case patients; for each case, three age/sex-matched patients with KD but without ICU stay, if identified, were selected as control patients. Clinical data were retrospectively collected and analyzed.

RESULTS

Among the total of 1065 KD patients, we identified 26 case patients and 71 controls for statistical analysis. ICU patients had a longer fever duration, and tended to have hemoglobin level < 10 g/dL, platelet count < 150 × 10⁹/L, band cell percentage > 10%, peak serum C-reactive protein level > 200 mg/L, serum albumin value < 3 g/dL, and often presented with multiorgan system involvement. Time from symptom onset to the diagnosis of KD was similar between the two groups, but ICU patients were less likely to have KD as a leading admission diagnosis. Shock (73.1%, n = 19) was the most common reason for ICU admission. ICU patients were more likely to receive antibiotics, albumin infusion, and require a second dose of intravenous immunoglobulin or steroid therapy. No in-hospital mortality was observed.

CONCLUSION

Patients with KD requiring ICU admission are significantly associated with multiorgan involvement, abnormal hematological and biochemistry biomarkers, KD recognition difficulty at the time of admission, and intravenous immunoglobulin-refractory KD.

Forme Fruste of HLH (haemophagocytic lymphohistiocytosis): diagnostic and therapeutic challenges

Infants and young children often present with a persistent febrile episode, sick appearance and negative infectious disease work-up. These patients present serious diagnostic and therapeutic problems to those who provide medical care, particularly since these children are clinically sick. We present a 13 month old child who presented with this clinical challenge. She was ultimately thought to have an incomplete form of HLH with underlying pathophysiology of hypercytokinemia, but also could have been a case of incomplete form of Kawasaki disease. She responded to IVIG, but this does not differentiate one diagnosis from another. Unfortunately we failed to obtain tests to exclude genetic etiologies of HLH, which would be important for predicting severity and risks of future recurrence. We wish to present this case so that one should do a thorough work up to establish a firm diagnosis of HLH and to search for genetic causes of this disorder.

High dose Anakinra for treatment of severe neonatal Kawasaki disease: a case report

We report an 11-week-old female who presented with Kawasaki disease (KD) complicated by macrophage activation syndrome (MAS). The infant presented to the hospital with persistent fever, cough, diarrhea, and emesis, among other symptoms. Her condition quickly began to decompensate, and she developed classic features (conjunctivitis, rash, cracked lips, distal extremity edema) prompting a diagnosis of acute KD. The patient was treated with standard therapy for KD including three doses of intravenous immunoglobulin (IVIG), aspirin, and high dose glucocorticoids with no change in her condition. Due to a high suspicion for MAS, high dose anakinra therapy was initiated resulting in dramatic clinical improvements. She also received one dose of infliximab for concern for coronary artery changes, and over the course of several months, anakinra and high dose glucocorticoids were tapered. Nearly complete reversal of echocardiogram changes were observed after 8 months, and the infant is now off all immunosuppressive therapy. In this case report, we briefly review the importance of early recognition of MAS in pediatric patient populations with rheumatic diseases, and we suggest early initiation of anakinra therapy as a rapid and effective treatment option.