Analysis of risk factors and prospective evaluation of cardiovascular complications of Kawasaki disease in children: a single centre study

Bridging a diagnostic Kawasaki disease classifier from a microarray platform to a qRT-PCR assay

BACKGROUND

Kawasaki disease (KD) is a systemic vasculitis that mainly affects children under 5 years of age. Up to 30% of patients develop coronary artery abnormalities, which are reduced with early treatment. Timely diagnosis of KD is challenging but may become more straightforward with the recent discovery of a whole-blood host response classifier that discriminates KD patients from patients with other febrile conditions. Here, we bridged this microarray-based classifier to a clinically applicable quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay: the Kawasaki Disease Gene Expression Profiling (KiDs-GEP) classifier.

METHODS

We designed and optimized a qRT-PCR assay and applied it to a subset of samples previously used for the classifier discovery to reweight the original classifier.

RESULTS

The performance of the KiDs-GEP classifier was comparable to the original classifier with a cross-validated area under the ROC curve of 0.964 [95% CI: 0.924-1.00] vs 0.992 [95% CI: 0.978-1.00], respectively. Both classifiers demonstrated similar trends over various disease conditions, with the clearest distinction between individuals diagnosed with KD vs viral infections.

CONCLUSION

We successfully bridged the microarray-based classifier into the KiDs-GEP classifier, a more rapid and more cost-efficient qRT-PCR assay, bringing a diagnostic test for KD closer to the hospital clinical laboratory.

IMPACT

A diagnostic test is needed for Kawasaki disease and is currently not available. We describe the development of a One-Step multiplex qRT-PCR assay and the subsequent modification (i.e., bridging) of the microarray-based host response classifier previously described by Wright et al. The bridged KiDs-GEP classifier performs well in discriminating Kawasaki disease patients from febrile controls. This host response clinical test for Kawasaki disease can be adapted to the hospital clinical laboratory.

Treatment and Coronary Artery Aneurysm Formation in Kawasaki Disease: A Per-Day Risk Analysis

OBJECTIVE

To assess whether 'treatment day' is a significant predicting factor in Kawasaki disease and imposes a risk for coronary artery aneurysms (CAAs) in a per-day analysis. CAA formation can be reduced from 25% to 10% when treated with intravenous immunoglobulin (IVIG).

STUDY DESIGN

Patient data from (n = 1016) a single center were collected for an observational cohort study. After exclusions, we retrospectively analyzed 776 patients in total. A multivariate analysis was performed with treatment day as a continuous variable (n = 691). Patients were categorized as no enlargement, small CAA, medium CAA, and giant CAA.

RESULTS

Late treatment per-day was a significant predicting factor for the development of larger CAAs. ORs for medium and giant CAAs per delayed day were 1.1 (95% CI 1.1-1.2) P < .05 and 1.2 (95% CI 1.1-1.2) P < .05, respectively.

CONCLUSION

We showed that every day of delay in treatment of patients with Kawasaki disease inherently carries a risk of medium and giant aneurysm formation. There was no cut-off point for treatment day that could mark a safe zone.

Tenascin-C predicts IVIG non-responsiveness and coronary artery lesions in kawasaki disease in a Chinese cohort

OBJECTIVES

To assess the predictive value of tenascin-C (TN-C) for intravenous immunoglobulin (IVIG) non-responsiveness and coronary artery lesions (CALs) development at the acute stage of Kawasaki disease, and to build novel scoring systems for identifying IVIG non-responsiveness and CALs.

METHODS

A total of 261 patients in acute-stage Kawasaki disease were included. Serum samples before IVIG initiation were collected and TN-C expression levels were measured using an enzyme-linked immunosorbent assay. In addition to TN-C, another fifteen clinical and laboratory parameters collected before treatment were compared between IVIG responsive and non-responsive groups, and between groups with and without CALs. Multiple logistic regression analyses were performed to construct new scoring systems for the prediction of IVIG non-responsiveness and CALs development.

RESULTS

IVIG non-responsive group (n = 51) had significantly higher TN-C level compared to IVIG responsive group (n = 210) (15.44 vs. 12.38 IU/L, P < 0.001). A novel scoring system composed of TN-C, total bilirubin, serum sodium and albumin was established to predict IVIG non-responsiveness. Patients with a total score ≥ 2 points were classified as high-risk cases. With the sensitivity of 78.4% and specificity of 73.8%, the efficiency of our scoring system for predicting IVIG non-responsiveness was comparable to the Kobayashi system. Consistently, the group developing CALs at the acute stage (n = 42) had significantly higher TN-C level compared to the group without CALs (n = 219) (19.76 vs. 12.10 IU/L, P < 0.001). A new scoring system showed that patients with elevated TN-C, platelet count ≥ 450 × 10⁹/L, and delayed initial infusion of IVIG had a higher risk of developing CALs. Individuals with a total score ≥ 3 points were classified as high-risk cases. The sensitivity and specificity of the novel simple system for predicting CALs development were 83.3% and 74.0%, respectively, yielding a better efficiency than the Harada score.

CONCLUSION

Elevated TN-C appeared to be an independent risk factor for both IVIG non-responsiveness and CALs in Chinese children with KD. Our scoring systems containing TN-C is simple and efficient in the early identification of high-risk KD cases that could benefit from more individualized medications.

Influenza infection and Kawasaki disease

INTRODUCTION

The objective of this study was to investigate the possible link between influenza (Flu) infection and Kawasaki disease (KD).

METHODS

We examined the medical records of 1,053 KD cases and 4,669 influenza infection cases hospitalized at our institute from January 1, 2011 to December 31, 2013. Cases of KD with concomitant influenza infection formed the KD + Flu group. Each KD + Flu case was matched with 2 KD cases and 2 influenza infection cases, and these cases were assigned to the KD group and Flu group, respectively. The differences in the principal clinical manifestations, course of disease, incomplete KD rate, intravenous immunoglobulin (IVIG) resistance rate, and echocardiographic detection results between the KD + Flu group and KD group were compared. The fever durations and laboratory test results of these three groups were compared.

RESULTS

1) The seasonal variations of the KD + Flu group, KD group and Flu group were similar. 2) The morbidity rate of incomplete KD was higher in the KD + Flu group compared with the KD group. 3) Patients in the KD + Flu group exhibited a longer time to KD diagnosis compared with patients in the KD group. 4) The KD + Flu group exhibited the longest fever duration among the three groups. 5) The CRP and ESR values in the KD + Flu group were higher those in the Flu or KD groups.

CONCLUSIONS

Concomitant influenza infection affects the clinical manifestations of KD and can impact the laboratory test results and the diagnosis and treatment of the disease. However, it remains unclear whether influenza contributes to KD etiology.