Serial changes of plasma nitrate in the acute phase of Kawasaki disease

Roles of Oxidative Injury and Nitric Oxide System Derangements in Kawasaki Disease Pathogenesis: A Systematic Review

Kawasaki disease (KD) is an acute febrile vasculitis that occurs mostly in children younger than five years. KD involves multiple intricately connected inflammatory reactions activated by a cytokine cascade. Despite therapeutic advances, coronary artery damage may develop in some patients, who will be at risk of clinical cardiovascular events and even sudden death. The etiology of KD remains unclear; however, it may involve both genetic and environmental factors leading to aberrant inflammatory responses. Given the young age of onset, prenatal or perinatal exposure may be etiologically relevant. Multisystem inflammatory syndrome in children, a post-infectious hyper-inflammatory disorder associated with severe acute respiratory syndrome coronavirus 2, has features that overlap with those of KD. Available evidence indicates that vascular endothelial dysfunction is a critical step in the sequence of events leading to the development of cardiovascular lesions in KD. Oxidative stress and the dysregulation of the nitric oxide (NO) system contribute to the pathogenesis of inflammatory responses related to this disease. This review provides current evidence and concepts highlighting the adverse effects of oxidative injury and NO system derangements on the initiation and progression of KD and potential therapeutic strategies for cardiovascular pathologies in affected children.

Elevated Inducible Nitric Oxide Levels and Decreased Hydrogen Sulfide Levels Can Predict the Risk of Coronary Artery Ectasia in Kawasaki Disease

Kawasaki disease (KD) is a vasculitis disease in children that is associated with coronary artery ectasia (CAE). We investigated whether inducible nitric oxide synthase (i-NOS) and hydrogen sulfide (H2S) could be used to predict CAE secondary to KD. We enrolled 65 children with KD (35 cases with CAE and 30 cases without CAE), 33 healthy children, and 32 children with fever but without vasculitis disease (febrile group). We measured plasma nitric oxide (NO), total nitric oxide synthase (Total-NOS), i-NOS, constructive nitric oxide synthase (c-NOS) levels, and H2S content in all patients. Plasma NO, Total-NOS, i-NOS, and H2S were higher in KD children than in healthy and febrile children (P < 0.05). The i-NOS level was higher in KD children with CAE compared to those without CAE, while the H2S was lower (both P < 0.05). Using a combination of i-NOS (higher than 10 U/mL) and H2S (lower than 3.31 μmol/L) to predict CAE had 80 % sensitivity and 81 % specificity (P < 0.05). Elevated plasma i-NOS and decreased plasma H2S levels in the acute phase of KD have good predictive value for CAE and may be used to guide appropriate clinical treatment and prevent future cardiovascular complications.

Asymmetric and symmetric dimethylarginine are associated with coronary artery lesions in Kawasaki disease

OBJECTIVE

To determine whether 3 biomarkers, L-arginine, asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA), can predict outcomes in patients with Kawasaki disease (KD).

STUDY DESIGN

Plasma levels of L-arginine, ADMA, and SDMA were measured in 39 patients with KD and 27 febrile control patients.

RESULTS

Plasma L-arginine, ADMA, and SDMA levels were lower in patients with KD than in control patients before treatment with intravenous immunoglobulin (IVIG; P=.027, P<.001, and P<.001, respectively). After treatment with IVIG, L-arginine, ADMA, L-arginine/ADMA ratios, and arginine methylation ([ADMA+SDMA]/L-arginine) increased significantly (P<.001, P=.001, P=.014, and P=.001, respectively). Compared with control patients, persistent lower SDMA and higher ADMA/SDMA ratios existed in patients with KD. Furthermore, a lesser magnitude of change in terms of L-arginine and ADMA/SDMA ratios after IVIG treatment was associated with the formation of coronary dilation (P=.025, and .029, respectively).

CONCLUSION

Levels of L-arginine, ADMA, and SDMA appear to be associated with KD. Lower L-arginine levels and ADMA/SDMA after treatment with IVIG was associated with coronary artery abnormalities patients with KD.

Increased nitric oxide production by neutrophils in early stage of Kawasaki disease

Recent observations suggested that nitric oxide (NO) has a role in triggering the early endothelial dysfunction in Kawasaki disease (KD). We investigated the amount of NO in conjunction with reactive oxygen species (ROS) produced by neutrophils in children with acute KD by a newly developed flow cytometric analysis. Forty children with acute KD (n = 14), non-KD febrile disease (n = 14), and afebrile control (n = 12) were enrolled (age, 3 to 88 months). Neutrophils in KD produced significantly higher amount of NO compared to others (p < 0.05). With regard to ROS, significant increase was not only found in KD but also in non-KD febrile children (p < 0.05 and p < 0.01, respectively). In KD patients, the amount of NO produced by neutrophils decreased after immunoglobulin (IVIG) treatment, while there was no significant change in ROS production. The amount of NO in KD patients also correlated well with the days from the onset. One patient who developed coronary arterial lesion showed the highest value of NO. In conclusion, neutrophils in acute KD generate both NO and ROS considerably, while NO production is exclusive in the early stage of KD before IVIG treatment. Abnormal immune system in KD might be characterized by an overproduction of NO, whereas the role of NO in endothelial damage remains to be elucidated.

Urinary oxidative stress markers in young patients with type 1 diabetes

BACKGROUND

Involvement of oxidative stress in the pathogenesis of diabetic vascular complications has been proposed. However, there are few methods to determine the status of oxidative stress both directly and quantitatively in young patients with type 1 diabetes.

METHODS

A total of 27 young patients with type 1 diabetes (mean age +/- SD, 12.6 +/- 4.2 years) with normal renal function and 38 healthy control subjects (13.0 +/- 4.6 years) were investigated. Early morning voiding urine samples were collected. The concentrations of acrolein-lysine adducts, 8-hydroxy-2'-deoxyguanosine (8-OHdG) were determined using competitive enzyme-linked immunosorbent assay, and nitric oxide metabolites were measured using the colorimetric, non-enzymatic assay.

RESULTS

Urinary concentrations of 8-OHdG, but not acrolein-lysine adducts and nitric oxide metabolites, were significantly increased in the diabetic group. For diabetic patients, microalbuminuria was significantly correlated with higher concentrations of all three markers. Hemoglobin A(1c) values were significantly correlated with 8-OHdG values.

CONCLUSIONS

These findings indicate that increased oxidative stress and the risk of vascular complications may be present at early stages of type 1 diabetes.

Pathogenesis and treatment of Kawasaki's disease

PURPOSE OF REVIEW

Coronary artery damage resulting from Kawasaki's disease is the leading cause of acquired heart disease in children in the developed world. This review highlights advances in our understanding of the etiology of Kawasaki's disease, the immune response leading to vascular damage, potential biomarkers, and insights into mechanisms of disease addressed by an animal model. Clinical dilemmas are discussed in the context of the new American Heart Association recommendations for the diagnosis and treatment of Kawasaki's disease.

RECENT FINDINGS

Improved understanding of the mechanisms of disease will assist in identifying predisposed individuals and in development of more effective therapy. Most investigators agree that an infectious trigger leads to massive activation of the immune system, resulting in a prolonged self-directed immune response at the coronary arteries. The etiology debate has centered on the nature of and mechanisms involved in immune activation. Genetic studies have not provided conclusive answers to these questions. Mechanistic studies done in animal models have pointed to specific biologic factors critical for coronary artery damage and together with studies in children may lead to more rationally conceived biologically based interventions. Increasingly, the questions regarding clinical management address timing of therapy and the management of children presenting with atypical Kawasaki's disease. New guidelines and management algorithms have been proposed by the American Heart Association to address these concerns.

SUMMARY

Biochemical and phenotypic characterization of Kawasaki's disease continues to improve. Answers are closer on etiology, reliable biomarkers, valid predictors of coronary outcome, and improved treatment of this syndrome.