摘要目的 观察雌鼠妊娠期卵清蛋白(OVA)暴露对仔鼠OVA再暴露的免疫反应作用.方法 采用前瞻性对照研究,将雌鼠不同孕期OVA暴露的仔鼠分为孕早期组、孕中期组、孕晚期组及平行对照组,各孕期组仔鼠于6~8周龄时多次OVA再暴露,观察记录小鼠症状并评分.酶联免疫吸附试验(ELISA)法检测仔鼠血清OVA特异性IgE及脾脏原代淋巴细胞体外OVA培养上清干扰素γ(IFN-γ)和白细胞介素4(IL-4)表达水平,进行单因素方差分析或秩和检验.结果 各孕期组仔鼠均发生急性腹泻但程度不同,孕晚期组仔鼠最早(2 d)出现腹泻,症状表现及评分亦突出,孕早期组、孕中期组、孕晚期组分别为(7.0±1.0)、(7.1±1.1)、(9.9±2.2)分(P<0.01);各孕期组仔鼠OVA特异性IgE升高,以孕晚期组仔鼠为著,吸光度(A)值:对照组、孕早期组、孕中期组、孕晚期组分别为0.27±0.06、0.51±0.13、0.50±0.09、0.63±0.13(P<0.01);各组仔鼠脾脏淋巴细胞培养上清IFN-γ无明显改变,对照组、孕早期组、孕中期组、孕晚期组分别为(133±7)、(133±4)、(134±6)、(132±4)pg/ml(P均>0.05);各孕期组仔鼠IL-4表达均升高,对照组、孕早期组、孕中期组、孕晚期组分别为(25.3±2.4)、(32.4±4.4)、(35.0±5.4)、(47.1±5.8)pg/ml(P均<0.01),以孕晚期组为著(P均<0.01).结论 雌鼠孕晚期OVA暴露仔鼠生后OVA再暴露的过敏反应更严重,提示孕晚期是仔鼠宫内致敏的高危时机,或为"窗口期".

abstractsObjective To observe the immunoreaction of offspring mice by ovalbumin ( OVA) re-exposure after their mothers exposed to OVA during pregnancy .Method A prospective controlled study was conducted to observe mice after repeated OVA exposures at 6-8 weeks.Their mothers were exposed to OVA during different stages of pregnancy .The symptoms were recorded and scored .The levels of OVA-specific IgE in serum,interferon-γ(IFN-γ) and interleukin-4(IL-4) in supernatant of spleen primary lymphocytes in vitro were measured by ELISA.The results were analyzed by single factor analysis of variance or rank sum test.Result All the mice in each group had acute diarrhea .The diarrhea happened earliest (2 days) and most severe in the late pregnancy group ( early pregnancy group 7.0 ±1.0;middle pregnancy group:7.1 ± 1.1; late pregnancy group:9.9 ±2.2, P<0.01).The levels of absorbance of OVA-specific IgE in the pregnancy groups were higher than those of the control group .The absorbance of OVA-specific IgE in late pregnancy group was the highest ( control:0.27 ±0.06;early pregnancy group:0.51 ±0.13; middle pregnancy group:0.50 ±0.09; late pregnancy group:0.63 ±0.13, P <0.01 ) .There was no significant change in IFN-γexpression in cultured supernatant of spleen lymphocytes in each group (control:(133 ±7) pg/ml;early pregnancy group:(133 ±4) pg/ml;middle pregnancy group:(134 ±6) pg/ml;late pregnancy group:(132 ±4) pg/ml,all P value >0.05).The expression of IL-4 in the experimental groups was higher than that in the control group , especially in late pregnancy group ( control:( 25.3 ±2.4 ) pg/ml; early pregnancy group:( 32.4 ±4.4 ) pg/ml; middle pregnancy group:( 35.0 ±5.4 ) pg/ml; late pregnancy group:(47.1 ±5.8) pg/ml;P value all<0.01).Conclusion The allergic reaction of the OVA re-exposure progeny whose mothers were exposed to OVA in the late pregnancy period was most severe , suggesting that late pregnancy period might be the high risk stage of intrauterine sensitization , or "window period".