Background
Kawasaki disease (KD) is an acute inflammation of the blood vessels that mainly affects children between six months and five years of age. Standard medical management of KD includes intravenous immunoglobulin (IVIG) with aspirin. This standard treatment is usually effective, but doesn't work for approximately 15% to 20% of children. When treatment is not effective, children may suffer from serious heart disease. Recently, researchers found that tumor necrosis factor-alpha (TNF-α) blockers may be effective for children with Kawasaki disease that has not been cured by standard treatment. However, we are still unclear about the benefits and risks of TNF-α blockers for the treatment of KD, and the potential for improved efficacy and safety is ambiguous. This review therefore assessed the benefits and harms of TNF-α blockers for the treatment of KD.
Study characteristics
We included trials that used TNF-α blockers as a treatment for children with KD and measured treatment resistance, cardiovascular events and side effects, such as infusion reactions and infections, or other symptoms. We found five completed studies with a total of 494 participants (most recent search for studies September 2018). Four studies used TNF-α blockers as the additional treatment after IVIG treatment and one used TNF-α blockers as the first treatment for children with KD.
Key results
The analyses showed that TNF-α blockers might reduce treatment resistance by 14% to 62% (low-certainty evidence) and infusion reactions by 55% to 99% (low-certainty evidence). It was not clear whether or not TNF-α blockers were effective in reducing serious heart diseases such as coronary artery abnormalities. There was also no clear difference in the incidence of infections between children who did or didn't receive TNF-α blockers.
Certainty of evidence
It is important to note that the certainty of evidence is low because the studies only included a small number of participants. Therefore, a large scale clinical trial is needed.
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 (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.
To evaluate the efficacy and safety of using TNF-α blockers (i.e. infliximab and etanercept) to treat children with Kawasaki disease.
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.
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.
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.
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.