HIV—1感染者的IgA类免疫反应的评价

IgA IMMUNE RESPONSES IN PATIENTS WITH HIV INFECTION

目的深入评价HIV感染者的IgA类免疫反应。方法将IgA类免疫反应产物分解为游离IgA、复合IgA和IgA／C3双特异性免疫复合物（IgA／C3—TCIC）三种组分，分别采用单向扩散法和ELISA技术进行分析。结果对68例无症状HIV感染者、120例AIDS患者和36例健康对照者的研究表明，HIV感染者的游离和复合IgA显著升高，IgA／C3—TCIC则明显下降，三者变化均与病情有一定关系，且其水平均在p24阳性组显著高于p24阴性组。游离IgA与CD4和CD4／CD8比率呈负相关，而与复合IgA和IgA／C3—TCIC呈正相关，但复合IgA和IgA／C3—TCIC间无明显相关性。结论不同IgA类组分的免疫学意义有差异，其中复合IgA和IgA／C3—TCIC是判断HIV感染早期及其进展的良好指标，而游离IgA不失为反映HIV感染后期的一个特征性指标。患者血清IgA显著升高可能与抑制性T细胞的数量下降和功能障碍有关。并提出可考虑通过干扰复合IgA的形成和促进复合IgA的清除等途径来作为治疗疾病的新手段。

Aim To further understand IgA immune responses in patients with HIV infection. Methods IgA immune responses were dissected into their components,namely free IgA,complexed IgA and IgA/C3 two-component-determined circulating immune complexes (IgA/C3 -TCIC ), which were detected by single radio immune diffusion or ELISA. Results Our study group included 36 HIV-seronegative controls, 68 asymptomaticHIV +subjects, 120 HIV + individuals with AIDS- related opportunistic infection. Both levels of free and complexed IgA were significantly increased in patients,but the amount of IgA/C3-TCIC was markedly reduced among them. All of the three markers were dramatically higher in p24+group than p24-one. Free IgA was negatively associated with CD4 and CD4/CDS ratio,and positively with .complexed IgA and IgA/C3 -TCIC. However,there were no relationship between complexed IgA and IgA/C3-TCIC. Conclusion These findings show thatcomplexed IgA and IgA/C3-TCIC may be better markers of early stage progression of HIV infection,and thatfree IgA may be a more valuable indicator in later stage disease. The mechanism of elevated serum IgA may be involved in CD4 numbers and function. Furthermore,a need for novel therapeutic strategies to modulate IgA immune responses in AIDS is suggested.