Serum immunoglobulin G, M and A response to Cryptosporidium parvum in Cryptosporidium-HIV co-infected patients

<p>Abstract</p> <p>Background</p> <p><it>Cryptosporidium parvum</it>, 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 <it>C. parvum </it>in HIV seropositive and seronegative patients co-infected with <it>Cryptosporidium </it>and to correlate the responses with symptomatology.</p> <p>Methods</p> <p><it>Cryptosporidium parvum </it>specific serum antibody (IgG, IgM and IgA) responses were assessed by ELISA in 11 HIV seropositive <it>Cryptosporidium </it>positive (Group I), 20 HIV seropositive <it>Cryptosporidium </it>negative (Group II), 10 HIV seronegative <it>Cryptosporidium </it>positive (Group III), 20 HIV seronegative <it>Cryptosporidium </it>negative healthy individuals (Group IV) and 25 patients with other parasitic diseases (Group V).</p> <p>Results</p> <p>A positive IgG and IgA antibody response was observed in significantly higher number of <it>Cryptosporidium </it>infected individuals (Gp I and III) compared to <it>Cryptosporidium </it>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 <it>Cryptosporidium </it>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/μl.</p> <p>Conclusion</p> <p>The study showed specific serum IgG and IgA production in patients infected with <it>Cryptosporidium</it>, both HIV seropositive and seronegative as compared to uninfected subjects suggesting induction of <it>Cryptosporidium </it>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 <it>Cryptosporidium </it>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 <it>Cryptosporidium </it>specific antibody responses may not be necessarily associated with protection from symptomatology.</p

Efficiency of diagnostic methods for correlation between prevalence of enteric protozoan parasites and HIV/AIDS status––an experience of a tertiary care hospital in East Delhi

Since the beginning of the AIDS pandemic, opportunistic infections have been recognized as common complications of HIV infection. Enteric protozoan parasitic infections are one of the leading causes of morbidity and mortality in HIV infected patients. The present study is, therefore, aimed to determine the prevalence of these parasites and study their association with immune status in HIV patients with emphasis on the correlation between various diagnostic techniques to give an accurate diagnosis to avoid empirical treatment. This prospective study, carried out between November 2009 and May 2010 included all HIV seropositive patients presenting with diarrhea to the ART center. A total of 64 stool samples were analyzed by wet mount examination, three different staining techniques, and antigen detection by ELISA for various enteric protozoan infections. Total prevalence of enteric protozoan parasites was 30%. Among the total cases, Cryptosporidium was seen in 12% cases followed by Giardia, E. histolytica and Isospora belli. The maximum diagnostic yield for coccidian parasites was with safranin–methylene blue staining technique. Parasitic burden contributes towards early morbidity in HIV infection. This study provides important information about prevalence of intestinal protozoan parasites in HIV infection. A combination of procedures should be carried out for the screening of stool specimens of HIV patients for better diagnosis and management

In vitro synthesized immunoglobulin A from nu/+ and reconstituted nu/nu mice against a dominant surface antigen ofGiardia lamblia

Nu/+ mice (ZU.ICR-strain) experimentally infected with Giardia lamblia (clone GS/M-83-H7) cleared the infection by day 45 postinfection (p.i.). Athymic nu/nu mice were reconstituted with immune Peyer's patch lymphocytes obtained from self-healed nu/+ littermates and thus acquired the potential to decrease their intestinal parasite mass. Intestinal B-cells from self-healed nu/+ mice as well as from immune-reconstituted athymic nude mice synthesized in vitro parasite-specific immunoglobulin A (IgA). This IgA was subsequently analyzed by immunoblotting, showing a predominant reaction with the major surface antigen (a 72,000-Da polypeptide) characterizing the Giardia clone in question. The hypothesis on the causative role of intestinal IgA and immune lymphocytes in the control of G. lamblia infection thus deserves further attention