Diagnostic characteristics of supplemental laboratory criteria for incomplete Kawasaki disease in children with complete Kawasaki disease

An Update on Reports of Atypical Presentations of Kawasaki Disease and the Recognition of IVIG Non-Responder Children

Kawasaki disease (KD) is an acute vasculitis with an intrinsic risk of severe involvement of coronary arteries. The worldwide spread of KD and the importance of early diagnosis for preventing cardiovascular complications have ascertained the need for updating guidelines for prompt disease recognition and treatment efficacy assessment. All KD patients who comply with the definition of classic or atypical disease should be treated with intravenous immunoglobulin (IVIG) soon after diagnosis. The objective of our narrative review was to analyze the medical literature about case reports with atypical KD in relation to diagnosis and potential identification of predictors of non-responsiveness to IVIG. Our analysis has shown that the seminal challenge in KD management is the timeliness of diagnosis, although both extreme variability and transience of clinical manifestations make this goal difficult. A non-negligible percentage of patients, especially in the first 6 months of life, might have atypical manifestations of KD, whose painstaking differential diagnosis may be tricky. Many attempts to develop universal scoring systems and detect children at higher risk of IVIG resistance have been rather unsuccessful. Additionally, KD may show different evolutions according to unraveled demographic, genetic, or epigenetic factors. Further research is needed to elucidate all open questions about KD and clarify the long-term outcome of its potential complications.

Kawasaki-like disease in children with COVID-19

Children with Coronavirus disease 2019 (COVID-19) are being reported to have manifestations of hyperinflammatory states and/or Kawasaki-like disease. In this study, we investigated children with typical and atypical Kawasaki disease (KD) likely to be associated with COVID-19. We have reported four children with Kawasaki-like disease probably associated with COVID-19. The clinical features were consistent with incomplete KD in three patients. SARS-CoV-2 RT-PCR was positive in one and the serology was positive in one patient with negative RT-PCR. Corticosteroids, anakinra, intravenous immunoglobulin (IVIG), and acetylsalicylic acid were used in the treatment. Three patients recovered after the treatment while one patient died. The literature review revealed 36 articles describing 320 children with Kawasaki-like disease associated with COVID-19. SARS-CoV-2 RT-PCR was negative in 120 (65.5%) of 183 patients while the serology was positive in 130 (83.8%) of 155 patients. The therapeutic options have included IVIG, acetylsalicylic acid, tocilizumab, anakinra, enoxaparin, and methylprednisolone. Pediatric COVID-19 cases may present with atypical/incomplete Kawasaki-like disease. Thus, pediatricians need to be aware of such atypical presentations resembling KD for early diagnosis of COVID-19.

Antibodies and Immunity During Kawasaki Disease

The cause of Kawasaki disease (KD), the leading cause of acquired heart disease in children, is currently unknown. Epidemiology studies support that an infectious disease is involved in at least starting the inflammatory cascade set off during KD. Clues from epidemiology support that humoral immunity can have a protective effect. However, the role of the immune system, particularly of B cells and antibodies, in pathogenesis of KD is still unclear. Intravenous immunoglobulin (IVIG) and other therapies targeted at modulating inflammation can prevent development of coronary aneurysms. A number of autoantibody responses have been reported in children with KD and antibodies have been generated from aneurysmal plasma cell infiltrates. Recent reports show that children with KD have similar plasmablast responses as other children with infectious diseases, further supporting an infectious starting point. As ongoing studies are attempting to identify the etiology of KD through study of antibody responses, we sought to review the role of humoral immunity in KD pathogenesis, treatment, and recovery.

B Cells and Antibodies in Kawasaki Disease

The etiology of Kawasaki disease (KD), the leading cause of acquired heart disease in children, is currently unknown. Epidemiology supports a relationship of KD to an infectious disease. Several pathological mechanisms are being considered, including a superantigen response, direct invasion by an infectious etiology or an autoimmune phenomenon. Treating affected patients with intravenous immunoglobulin is effective at reducing the rates of coronary aneurysms. However, the role of B cells and antibodies in KD pathogenesis remains unclear. Murine models are not clear on the role for B cells and antibodies in pathogenesis. Studies on rare aneurysm specimens reveal plasma cell infiltrates. Antibodies generated from these aneurysmal plasma cell infiltrates showed cross-reaction to intracellular inclusions in the bronchial epithelium of a number of pathologic specimens from children with KD. These antibodies have not defined an etiology. Notably, a number of autoantibody responses have been reported in children with KD. Recent studies show acute B cell responses are similar in children with KD compared to children with infections, lending further support of an infectious disease cause of KD. Here, we will review and discuss the inconsistencies in the literature in relation to B cell responses, specific antibodies, and a potential role for humoral immunity in KD pathogenesis or diagnosis.

Clinical implications in laboratory parameter values in acute Kawasaki disease for early diagnosis and proper treatment

Purpose

This study aimed to analyse laboratory values according to fever duration, and evaluate the relationship across these values during the acute phase of Kawasaki disease (KD) to aid in the early diagnosis for early-presenting KD and incomplete KD patients.

Methods

Clinical and laboratory data of patients with KD (n=615) were evaluated according to duration of fever at presentation, and were compared between patients with and without coronary artery lesions (CALs). For evaluation of the relationships across laboratory indices, patients with a fever duration of 5 days or 6 days were used (n=204).

Results

The mean fever duration was 6.6±2.3 days, and the proportions of patients with CALs was 19.3% (n=114). C-reactive proteins (CRPs) and neutrophil differential values were highest and hemoglobin, albumin, and lymphocyte differential values were lowest in the 6-day group. Patients with CALs had longer total fever duration, higher CRP and neutrophil differential values and lower hemoglobin and albumin values compared to patients without CALs. CRP, albumin, neutrophil differential, and hemoglobin values at the peak inflammation stage of KD showed positive or negative correlations each other.

Conclusion

The severity of systemic inflammation in KD was reflected in the laboratory values including CRP, neutrophil differential, albumin, and hemoglobin. Observing changes in these laboratory parameters by repeated examinations prior to the peak of inflammation in acute KD may aid in diagnosis of early-presenting KD patients.

Suppressed plasmablast responses in febrile infants, including children with Kawasaki disease

Background

Kawasaki disease (KD), the leading cause of acquired heart disease in children, primarily affects infants and toddlers. Investigations on immune responses during KD are hampered by a limited understanding of normal immune responses in these ages. It’s well known that Infants have poorer vaccine responses and difficulty with maintaining prolonged serum immunity, but there are few studies on human infants detailing immune deficiencies. Limited studies propose an inability to maintain life-long bone marrow plasma cells. Plasmablasts are a transitional cell form of B cells that lead to long-term Plasma cells. Plasmablasts levels rise in the peripheral blood after exposure to a foreign antigen. In adult studies, these responses are both temporally and functionally well characterized. To date, there have been few studies on plasmablasts in the predominant age range of KD.

Methods

Children presenting to an urban pediatric emergency room undergoing laboratory evaluation, who had concern of KD or had fever and symptoms overlapping those of KD, were recruited. Peripheral blood mononuclear cells were isolated and evaluated utilizing flow cytometry with specific B cell markers from 18 KD subjects and 69 febrile controls.

Results

Plasmablast numbers and temporal formation are similar between infectious disease controls and KD subjects. In both groups, infants have diminished plasmablast responses compared to older children.

Conclusion

In this single-time point survey, infants have a blunted peripheral plasmablast response. Overall, similar plasmablast responses in KD and controls support an infectious disease relationship to KD. Future time-course studies of plasmablasts in infants are warranted as this phenomenon may contribute to observed immune responses in this age group.

Changes in clinical and laboratory features of Kawasaki disease noted over time in Daejeon, Korea

BACKGROUND

Kawasaki disease (KD) becomes one of the common diseases in Korea. Changes in clinical features and laboratory findings of KD were evaluated over a period of 10 years.

METHODS

We reviewed the medical records of KD patients and compared the clinical and laboratory features of two KD patient groups: those admitted from 2000 to 2004 (group A, 284 cases) and those admitted from 2010 to 2014 (group B, 331 cases).

RESULTS

There were a total of 615 KD patients (mean age: 29.7 months; male-to-female ratio = 1.6:1), including 228 incomplete KD patients. Incomplete KD patients had milder values in some laboratory indices. The preadmission and total fever durations were longer in group A than in group B. The proportion of incomplete KD was higher in group B, but incidence of coronary artery lesions (CALs) was lower. For laboratory indices, the C-reactive protein and follow-up platelet values were lower, and the hemoglobin and albumin values were higher in group B. The same clinical and laboratory findings were confirmed in the KD subgroups; those with the same fever duration of 5 or 6 days and same ages, those with complete KD, and those with incomplete KD in the two different time periods.

CONCLUSIONS

Our findings suggest that clinical features of KD tend to be milder over time and manifest in a higher incidence of incomplete KD, lower incidence of CALs, and less severe laboratory findings in recent KD patients in Korea compared with their historic counterparts.

Bacillus Calmette-Guérin reactivation as a sign of incomplete Kawasaki disease

Kawasaki disease (KD) is an acute, self-limited, systemic vasculitis of unknown aetiology, extremely rare in infants younger than 6 months old. Younger infants are more likely to present with incomplete KD (IKD) and are at higher risk of developing coronary abnormalities. An early and specific clinical sign, not included in the classical diagnosis criteria, but that can be very useful in the diagnosis of KD, is the reaction at the Bacillus Calmette-Guérin (BCG) inoculation site. We describe a case of a 4-month-old boy, fully immunised, whose BCG scar reactivation led to the diagnosis of IKD. This case-report emphasises the importance of BCG site reactivation in establishing a diagnosis of IKD that clinicians should be aware of, especially in countries where BCG vaccination is still part of the immunisation schedule.