【摘要】 【目的】探讨学龄前反复呼吸道感染(recurrent respiratory tralt in fection,RRI)儿童维生素A(VA)水平与免疫功能变化。【方法】采用微量荧光分光光度法、流式细胞术、淋巴细胞体外增殖试验、酶联免疫吸附法及速率散射比浊法测定学龄前RRI组和对照组儿童血清VA水平及免疫功能。【结果】RRI组儿童血清VA均值(0.92±0.38)μmol/L低于对照组(1.24±0.35)μmol/L水平,儿童亚临床维生素A缺乏(sub-clinical syndrome vitamin Adeficiency SVAD)发生率10.4%和可疑SVAD发生率28.3%高于对照组6.8%和17.2%,差异均有统计学意义(P<0.05,P<0.01)。淋巴细胞亚群结果表明:RRI组儿童CD3+绝对数,CD4+百分数和绝对数,CD3/HLA-DR百分数及CD4+/CD8+比值明显低于对照组,差异均有统计学意义(P<0.05,P<0.01)。CD8+百分数和绝对数高于对照组,差异有统计学意义(P<0.05)。RRI组儿童外周血γ-INF(94.80±63.29)和IL-2(131.52±35.47)ng/L低于对照组(172.95±70.41)和(192.39±31.38)ng/L水平,差异均有统计学意义(P<0.05)。IL-4(63.84±11.40)ng/L和IL-10(411.95±76.39)ng/L明显高于对照组(14.93±9.29)和(172.64±82.07)ng/L水平(P<0.01)。RRI组儿童血清IgG(5.27±3.51)g/L低于对照组(7.35±3.23)g/L水平,差异具有统计学意义(P<0.05)。【结论】学龄前RRI儿童血清VA低于健康儿童水平,即存在较高SVAD和可疑SVAD状况。同时伴有免疫功能紊乱,表现为淋巴细胞亚群和细胞因子水平失衡,T淋巴细胞增殖功能发生障碍和体液免疫受到损害。更多还原

【Abstract】 [Objective] To investigate the changes of vitamin A level and immune function in preschool children with recurrent respiratory tract infection (RRI). [Methods] The vitamin A level was determined with fluorometry. The percentage and Absolute count of lymphocytes subsets were measured with flow cytometry. T lymphocytes proliferation capacities and CD3/HLA-DR percentage were assayed by MTS/PMS proliferation assay and flow cytometry. The levels of cytokines and immunoglobulin were examined by ELISA and rate nephelometry. [Results] The serum VA level of RRI(0.92±0.38)μmol/L was statistically lower than that of healthy children [(1.24±0.35)μmol/L,P<0.05]. The prevalence of sub-clinical syndrome vitamin A deficiency (SVAD) and suspected SVAD in RRI children was statistically higher than controls (10.4 % vs 6.8 %,P<0.05 &28.3 % vs 17.2 %,P< 0.01 ).In RRI children the Absolute count of CD3+.lymphocytes,percentage and Absolute count of CD4+ lymphocytes,the percentage of CD3/HLA-DR and the ratio of CD4+/CD8+ were obviously lower than controls (P<0.05,P<0.01).The percentage and Absolute count of CD8+ lymphocytes were obviously higher than controls (P<0.05). Compared Th1/Th2 cytokines in RRI children with controls,it was showed that the level of γ-INF and IL-2 were significantly decreased[(94.80±63.29) vs (172.95±70.41)ng/L,P<0.05&(131.52±35.47) vs (192.39±31.38)ng/L,P<0.05]. Meanwhile,the level of IL-4 and IL-10 were significantly increased[(63.84±11.40 )vs (14.93±9.29)ng/L,P<0.01&(411.95±76.39 )vs(172.64±82.07 )ng/L ,P<0.01]. Immunoglobulin G was significantly lower than controls [(5.27±3.51 )vs(7.35±3.23 )g/L,P<0.05]. [Conclusions] The results suggested that vitamin A level decreased in preschool children with RRI accompanying with the imbalance of cellular immunity and the damage of humoral immunity.更多还原