Department of Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh-160 012, India.
BMC Infect Dis. 2009 Nov 18;9:179. doi: 10.1186/1471-2334-9-179.
Cryptosporidium parvum, the protozoan parasite, causes a significant enteric disease in immunocompromised hosts such as HIV patients. The present study was aimed to compare serum IgG, IgM and IgA responses to crude soluble antigen of C. parvum in HIV seropositive and seronegative patients co-infected with Cryptosporidium and to correlate the responses with symptomatology.
Cryptosporidium parvum specific serum antibody (IgG, IgM and IgA) responses were assessed by ELISA in 11 HIV seropositive Cryptosporidium positive (Group I), 20 HIV seropositive Cryptosporidium negative (Group II), 10 HIV seronegative Cryptosporidium positive (Group III), 20 HIV seronegative Cryptosporidium negative healthy individuals (Group IV) and 25 patients with other parasitic diseases (Group V).
A positive IgG and IgA antibody response was observed in significantly higher number of Cryptosporidium infected individuals (Gp I and III) compared to Cryptosporidium un-infected individuals (Gp II, IV and V) irrespective of HIV/immune status. Sensitivity of IgG ELISA in our study was found to be higher as compared to IgM and IgA ELISA. The number of patients with positive IgG, IgM and IgA response was not significantly different in HIV seropositive Cryptosporidium positive patients with diarrhoea when compared to patients without diarrhoea and in patients with CD4 counts <200 when compared to patients with CD4 counts >200 cells/microl.
The study showed specific serum IgG and IgA production in patients infected with Cryptosporidium, both HIV seropositive and seronegative as compared to uninfected subjects suggesting induction of Cryptosporidium specific humoral immune response in infected subjects. However, there was no difference in number of patients with positive response in HIV seropositive or seronegative groups indicating that HIV status may not be playing significant role in modulation of Cryptosporidium specific antibody responses. The number of patients with positive IgG, IgM and IgA response was not significantly different in patients with or without history of diarrhoea thereby indicating that Cryptosporidium specific antibody responses may not be necessarily associated with protection from symptomatology.
微小隐孢子虫是一种原生动物寄生虫，会导致免疫功能低下的宿主（如 HIV 患者）发生严重的肠道疾病。本研究旨在比较 HIV 血清阳性和阴性的隐孢子虫合并感染患者对微小隐孢子虫粗可溶性抗原的血清 IgG、IgM 和 IgA 反应，并将这些反应与症状相关联。
采用 ELISA 法检测 11 例 HIV 血清阳性的隐孢子虫阳性（I 组）、20 例 HIV 血清阳性的隐孢子虫阴性（II 组）、10 例 HIV 血清阴性的隐孢子虫阳性（III 组）、20 例 HIV 血清阴性的隐孢子虫阴性健康个体（IV 组）和 25 例其他寄生虫病患者（V 组）的微小隐孢子虫特异性血清抗体（IgG、IgM 和 IgA）反应。
与未感染隐孢子虫的个体（II、IV 和 V 组）相比，感染隐孢子虫的个体（I 组和 III 组）中观察到更高比例的 IgG 和 IgA 抗体阳性反应，而不论 HIV/免疫状态如何。在本研究中，IgG ELISA 的敏感性高于 IgM 和 IgA ELISA。与无腹泻的患者相比，腹泻的 HIV 血清阳性的隐孢子虫阳性患者的 IgG、IgM 和 IgA 阳性反应的患者数量没有显著差异，与 CD4 计数<200 的患者相比，CD4 计数>200 个细胞/微升的患者的 IgG、IgM 和 IgA 阳性反应的患者数量也没有显著差异。
该研究表明，与未感染的个体相比，感染微小隐孢子虫的 HIV 血清阳性和阴性患者均产生特异性血清 IgG 和 IgA，表明感染的个体中诱导了微小隐孢子虫特异性体液免疫反应。然而，在 HIV 血清阳性或阴性组中，阳性反应的患者数量没有差异，表明 HIV 状态可能在调节微小隐孢子虫特异性抗体反应中没有发挥重要作用。有或没有腹泻病史的患者的 IgG、IgM 和 IgA 阳性反应的患者数量没有显著差异，这表明微小隐孢子虫特异性抗体反应不一定与避免症状相关。
