Impact of ketogenic diet on follicular helper T cells in children with intractable epilepsy / 中华实用儿科临床杂志

ABSTRACT

Objective To explore the impact of ketogenic diet (KD) on follicular helper T cells(TFH) in children with intractable epilepsy.Methods Thirty-three cases with intractable epilepsy were selected between Jul.2013 and Jan.2014 in Shenzhen Children's Hospital,19 boys and 14 girls; average age was 39.6 months,and seventeen age-matched healthy children who took a physical examination in the same hospital were assigned as the healthy control group.Blood samples were collected from the children with refractory epilepsy before and after 1 week of KD treatment.The proportions of the various stages of B cells and TFH cells were detected by flow cytometry.The plasma concentration of interleukin-21 (IL-21) was determined by enzyme-linked immunosorbent assay(ELISA),and realtime quantitative PCR(RT-PCR) was performed to detect the levels of peroxisome proliferator-activated receptor gamma (PPAR-γ),B-lymphocyte-induced maturation protein-1 (Blimp-1),B-cell lymphoma 6 (Bcl6) and IL-21 mRNA expression in CD4 + T cells.Results (1) The number of TFH cells in children with intractable epilepsy [(3.57 ± 0.58) ％] was remarkably decreased after KD treatment(P ＜ 0.01),while there were no difference between after KD treatment and healthy control group[(4.93 ±0.70)％ vs (5.03 ±0.63)％,P ＞0.05].(2) The levels of transcription factor Bcl6 expression after treatment were significantly decreased,while inhibitory factor Blimp-1 expression increased (P ＜ 0.05).(3)The plasma concentration of IL-21 had a trend to decrease (P ＞ 0.05),while there were no difference before and after KD treatment,and levels of IL-21 mRNA expressions in CD4 +T cells were significantly decreased after the treatment (8.28 × 10-3 ± 1.19 × 10-3 vs 1.72 × 10-2 ± 0.81 × 10-2,t =3.08,P ＜ 0.05).(4) There was no significant difference in CD27-IgD + B cells before and after KD treatment (P ＞ 0.05),CD27 + IgD + B cell and CD27-IgD-B cells had a trend to decrease after KD treatment(P ＞0.05),and CD27 + IgD-B cells and CD27 + IgD-CD38 high plasma cells were significantly decreased after KD treatment (P ＜ 0.05).(5) The number of TFH cells were correlated positively with the number of CD27 + IgD-B cells and CD27 + IgD-CD3g high plasma cells (r =0.785,0.745,P ＜ 0.05).(6) The levels of PPAR-γmRNA in CD4 + T cells expression were significantly up-regulated after KD treatment (3.49 × 10-3 ± 1.10 × 10-3 vs 2.28 ± 10-3 ± 1.30 × 10-3,t =3.41,P ＜0.05),and the number of TFH cells and PPAR-γgene expression was correlated negatively (r =-0.619,P ＜ 0.05).Conclusions KD might down regulate TFH cell number and function through inducing PPAR-γexpression and could inhibit B cell differentiation,which might be one of the factors for hypogammaglobuinemia by KD treatment.