52 - EFFECT OF ADDITIONAL INTRAVENOUS IMMUNOGLOBULIN FOR INFLIXIMAB-REFRACTORY KAWASAKI DISEASE

Background

Achieving early fever resolution is crucial for KD patients resistant to IVIG, those at a higher risk of developing coronary artery lesions (CALs). Although infliximab (IFX) is a reasonable choice of treatment for IVIG-resistant KD patients, nationwide surveys in Japan demonstrated that additional treatment was still required for 20-30% of patients after IFX infusion. Additional IVIG is often selected as the treatment for KD refractory to IFX. However, there have been no reports on its therapeutic effect. We aimed to describe the therapeutic effect of IVIG after IFX for KD.

Methods

We mainly analyzed the IVIG-after-IFX group, that is, those who were treated with additional IVIG for IFX-refractory KD, between January 2016 and March 2023. We also examined the second-IVIG group, which consists of KD patients refractory to initial IVIG and received the second IVIG during 2016, as a comparison group. We employed descriptive statistics and survival analysis methods to represent their clinical courses including the presence of CALs and the time from initiation of the treatment to resolution of fever.

Results

The analysis included 24 cases of the IVIG-after-IFX group and 38 cases of the second-IVIG group. In the analysis of the IVIG-after-IFX group, IFX was administered as the 3rd line treatment in 20 cases (83%), with 1 case in the 2nd line, 2 cases in the 4th line, and 1 case in the 5th line. The additional IVIG after IFX was initiated on the median 11 days of illness (range 8-29). Among the 24 cases of the IVIG-after-IFX group, corticosteroids were used in 10 cases during the course. CALs were identified in 5 cases before initiating IVIG after IFX, and 2 cases showed new CALs after IVIG after IFX.

The median time until fever resolution was 0.75 days in the IVIG-after-IFX group and 1.0 day in the second-IVIG group (P value 0.388 by log-rank test, hazard ratio 0.87; 95% confidence interval 0.50-1.52 by Cox regression analysis). The fever resolved within 2.0 days after the initiation of the therapy in 83% (20/24 cases) in the IVIG-after-IFX group and 68% (26/38 cases) in the second-IVIG group. In addition to IVIG after IFX, 4 cases received further treatment, including cases where fever did not resolve following IVIG after IFX and cases where fever resolution was achieved but with sustained elevated C-reactive protein levels.

Conclusion


IVIG after IFX for KD demonstrates a therapeutic effect comparable to that of the second IVIG.