过敏性紫癜病儿树突细胞分泌白细胞介素-12水平与T_H1/T_H2的变化

Levels of IL-12 produced by dendritic cells and changes of T_H1/T_H2 balance in children with Henoch-Schonlein purpura

目的观察过敏性紫癜(HSP)病儿外周血树突细胞(DC)产生IL12的变化,并探讨其对TH1/TH2平衡的影响及在HSP发病机制中的意义。方法应用酶联免疫吸附试验(ELISA)检测60例HSP病儿(HSP组)及21例健康儿童(对照组)血浆干扰素γ(IFNγ)、白细胞介素4(IL4)、白细胞介素12(IL12)水平。并对其中22例HSP病儿及21例健康儿童外周血单个核细胞(PBMC)进行体外培养以诱生出DC,用ELISA法检测培养上清液中IL12水平,同时应用间接免疫荧光法检测CD1a+细胞表达率。结果①HSP组血浆IFNγ水平低于对照组(30.59±11.27pg/mLvs43.38±19.19pg/mL,P<0.01),IL4水平高于对照组(45.08±9.19pg/mLvs32.95±7.10pg/mL,P<0.01),IFNγ/IL4比值低于对照组(0.70±0.28vs1.33±0.57,P<0.01),IL12水平低于对照组(153.95±91.88pg/mLvs323.06±162.34pg/mL,P<0.01);HSP组和对照组各自血浆中IL12水平与IFNγ水平呈正相关(P<0.01,0.05),与IL4水平无相关性(P>0.05),与IFNγ/IL4比值呈正相关(P<0.01)。②HSP组培养上清液IL12水平低于对照组(357.06±153.56pg/mLvs489.80±213.45pg/mL,P<0.05),且与血浆IL12水平呈正相关(P<0.01)。③HSP组CD1a+细胞表达率低于对照组(27.42±10.75)%vs(35.68±12.18)%,(P<0.05),与培养上清液和血浆IL12水平皆呈正相关(P<0.01)。结论HSP病儿存在TH1/TH2平衡失调,TH1功能的下降与血浆IL12水平低下呈正相关,而后者又与DC数量减少和/或功能低下关系密切,表明HSP病儿外周血DC数量减少和/或功能低下间接导致了TH1/TH2平衡的失调。

Objective To study the changes of IL-12 produced by dendritic cells in peripheral blood in children with Henoch-Schonlein purpura （HSP） , and to explore its influence on TH1/TH2 balance in order to elucidate its significance in the pathogenesis of HSP, Methods The levels of interferon-γ （IFN-γ）, interlenkin-4 （IL-4） and interleukin-12 （IL-12） in plasma were determined by ELISA in 60 HSP children （ HSP group） and 21 healthy children （ Control group）. Peripheral blood mononuclear cells （PBMC） of 22 HSP patients and 21 healthy children were cultured in vitro and then were transformed into dendritic cells, The levels of IL-12 in the supernatant were detected by ELISA and the positive expression rate of CD1 a^＋ was detected by indirect immunofluorescence procedure. Results ①The levels of IFN-γ and the ratio of IFN-γ/IL-4 in plasma of the HSP group were lower than those of the Control group （ IFN-γ 30. 59±11.27 pg/mL vs 43.38 ±19.19 pg/mL; IFN-γ/IL-4 ratio 0. 70 ± 0. 28 vs 1. 33 ± 0.57 ） （ P 〈 0. 01 ）, The levels of IL-12 in the HSP group were also lower than those of the Control group （ 153. 95 ±91.88 pg/mL vs 323. 06 ± 162. 34 pg/mL; P 〈 0. 01 ）, In contrast, the levels of IL-4 were higher than those of the Control group （45. 08 ±9. 19 pg/mL vs 32.95±7. 10 pg/mL; P 〈0, 01 ）, The plasma levels of IL-12 positively correlated with the IFN-γ levels （r = 0, 52, P 〈 0. 01 ） and the ratio of IFN-γ/IL-4 （r =0.43, P 〈0.01 ） in the HSP group. ②The IL-12 levels in the supernatant of the HSP group were lower than those of the Control group （357. 06 ±153.56 pg/mL vs 489. 80 ± 213. 45 pg/mL; P 〈 0, 05 ）, and had a positive correlation with the plasma IL-12 levels （ r =0. 74, P 〈0. 01 ）, ③The positive expression rate of CD1a^＋ of the HSP group was lower than that of the Control group [（27.42 ± 10,75）% vs （35.68 ± 12, 18）%; P〈0.05], and positively correlated with the IL-12 levels in the supernatants （ r = 0. 57, P 〈 0.01 ） and in plasma （ r = 0. 68, P〈0.01 ）,Conclusions There was an imbalance of TH1/TH2 in HSP children. The decrease of TH1 function had a positive correlation with the low levels of IL-12 in plasma, while the latter correlated closely with decreased number and / or function of dendritic cells, suggesting that the decreased number and / or function of dendritic cells in peripheral blood resulted in the imbalance of TH1/TH2 indirectly.