Immune-monitoring in Kawasaki disease patients treated with infliximab and intravenous immunoglobulin

Abstract

The expansion of regulatory T cells (Treg ) controls inflammation in children with acute Kawasaki disease (KD). Blockade of tumour necrosis factor (TNF)-α is an emerging therapy for KD patients with refractory inflammation, but there is concern that this therapy could impede the host immune regulation. To define the effect of TNF-α blockade, we conducted ex-vivo immune-monitoring in KD subjects who participated in a randomized, double-blind, placebo-controlled clinical trial of the addition of infliximab to standard intravenous immunoglobulin (IVIG) therapy. We enumerated circulating myeloid and plasmocytoid dendritic cells (DC), regulatory T cells (Treg ) and memory T cells (Tmem ) in 14 consecutive, unselected KD patients (seven treated with IVIG, seven with IVIG + infliximab) at three time-points: (i) acute phase prior to treatment, (ii) subacute phase and (iii) convalescent phase. Myeloid DC (mDC), but not plasmacytoid DC (pDC), were numerous in the peripheral blood in acute KD subjects and decreased in the subacute phase in both IVIG(-) and IVIG (+) infliximab-treated groups. The co-stimulatory molecule for antigen presentation to T cells and CD86 decreased in mDC from acute to subacute time-points in both treatment groups, but not in the single patient who developed coronary artery aneurysms. We also defined tolerogenic mDC that expand in the subacute phase of KD not impaired by infliximab treatment. Treg and Tmem expanded after treatment with no significant differences between the two groups. Treatment of KD patients with infliximab does not adversely affect generation of tolerogenic mDC or the development of T cell regulation and memory.

Trial registration: ClinicalTrials.gov NCT00760435.

Keywords: Kawasaki disease; T cells; dendritic cells; infliximab; vascular inflammation.

Fig. 1

Quantification of myeloid dendritic cells (mDC) defined as CD11c⁺CD11b⁺ from subjects with acute Kawasaki disease (KD) prior to treatment and from febrile control children. Double-positive CD11c⁺CD11b⁺ mDC in 14 acute KD and four viral controls are shown.

Fig. 2

Myeloid dendritic cells (mDC) in 14 acute and 12 subacute Kawasaki disease (KD) subjects. mDC as a percentage of total peripheral blood mononuclear cells (PBMC) decreased from the acute to subacute period in both treatment groups (a, median ± 1 standard error, and c). However, the median percentage activated (CD86⁺) mDC decreased only in the infliximab-treated group (b,d). Blue line: placebo + intravenous immunoglobulin (IVIG); red line: infliximab + IVIG; dotted line: patients with dilated coronary arteries; dashed line: patient with coronary artery aneurysm. Two acute circled patients (one each in the placebo and infliximab groups) were not sampled at the subacute time-point. The change in Z-score for the left anterior descending artery from baseline to 2 weeks was plotted against delta mDC% (e, CD11c⁺CD11b⁺) or delta activated mDC% (f, CD11c⁺CD11b⁺CD86⁺). A strong correlation was seen for the infliximab-treated patients.

Fig. 3

CD14⁺ myeloid dendritic cells (mDC) in 14 acute and 12 subacute Kawasaki disease (KD) patients. CD14⁺ mDC as a percentage of total peripheral blood mononuclear cells (PBMC) increased from the acute to subacute period in both treatment groups [a, median ± 1 standard error (s.e.)]. Also the median percentage activated (CD86⁺) CD14⁺ mDC increased in placebo + intravenous immunoglobulin- (IVIG) and infliximab + IVIG-treated group (a, median ± 1 s.e.). CD14⁺ mDC derived from an acute KD subject are DR⁺ and co-express blood dendritic cell antigen 1 (BDCA-1), immunoglobulin-like transcript (ILT)-4 and human leucocyte antigen (HLA)-G (b). Fluorescence activated cell sorted (FACS) CD14⁺ mDC cultured with purified Fc fragments secrete IL-10 (c).

Fig. 4

CD4⁺CD25^high regulatory T cells (T_reg) in acute Kawasaki disease (KD) and 2–4 weeks after treatment. The expansion of T_reg in seven placebo + intravenous immunoglobulin (IVIG)- and seven infliximab + IVIG-treated KD patients was measured prior to treatment (empty symbols) and 2–4 weeks after treatment (full symbols).

Fig. 5

Effector and central memory T cells CD4⁺ and CD8⁺ memory T cells were enumerated in acute, subacute and convalescent Kawasaki disease (KD) subjects. CCR7⁻ effector and CCR7⁺ central CD4⁺ memory T cells (upper panels) and CD8⁺ memory T cells (lower panels) have been measured in acute, subacute and convalescent KD patients in placebo + intravenous immunoglobulin (IVIG) (empty symbols) and infliximab + IVIG groups (median ± 1 standard deviation).