ABSTRACT
Toxoplasma gondii, the obligate intracellular parasite is life threatening in AIDS patients. Diagnosis of toxoplasmosis is based on serological methods especially increasing of IgM and IgG titers, but finding of parasite or its components [antigenemia] may be beneficial method in order to detection of acute toxoplasmosis in immunocompromised patients. Ninety-four serum samples from HIV positive patients were collected from Sanandaj, Kordistan west of Iran. These patients were lived in Sanandaj of whom 26 were prisoners infected with HIV virus in prison. Toxoplasma gondii antibodies were determined by IgG ELISA. T. gondii antigen was identified by capture- ELISA. PCR was performed on samples with T. gondii antigenemia. CD4+ T cells counts had been determined by flowcytometry and were obtained from records of each patient. Among the examined HIV seropositive individuals, 19.1% [18/94] and 5.3% [5/94] were positive for Toxoplasma-IgG and antigenemia, respectively. Besides, one of the samples was positively detected by PCR method. Mean age of participants was 37.9 +/- 9.5 year. Prevalence of IgG antibody and antgenemia was higher in age group of 40-50 years old. The Mean of CD4+ T cells counts of participants [total of HIV+ patients, IgG positive patients and patients with antigenemia] was 699.2 +/- 345.2, 655.1 +/- 237.9 and 620.2 +/- 215.1 respectively. Capture-ELISA and PCR could confirm the T. gondii acute infection in HIV positive patients. For precise diagnosis of acute toxoplasmosis in HIV positive patient, performance of more studies based on more sensitive types of PCR is suggested
Subject(s)
Humans , Male , Female , Toxoplasmosis/epidemiology , HIV , Enzyme-Linked Immunosorbent Assay , Polymerase Chain Reaction , Immunoglobulin GABSTRACT
Toxoplasma gondii is an obligate intracellular parasite that infects a broad range of warm- blooded animals including human. Tachyzoites of T.gondii invade the host cell, replicate and finally lead to the lysis of the cell. T. gondii is associated with congenital infection and it can cause encephalitis, or systemic infection in immunocompromised patients. It is important to know whether the infection is recently acquired or is chronic. Differentiation between acute and chronic infection has a dramatic impact, especially for the developing fetus. In this study, Toxoplasma gondii was detected in acute phase of infection in serum sample of a person who had been accidentally infected with tachyzoites of RH strain in the laboratory. Anti- T.gondii IgG antibody was prepared by rabbit immunization with soluble antigen of tachyzoites of RH strain. Capture- ELISA, immunoblotting and PCR were performed in the laboratory. Antigenemia and parasitemia was detected in serum sample of infected person by capture_ELISA, immunoblotting and PCR techniques respectively. Acute T.gondii infection could be detectable in a short period of time in the sera of infected person
Subject(s)
Humans , Animals , Acute Disease , Toxoplasma/isolation & purification , Rabbits , Antigens, ProtozoanABSTRACT
Serum samples, 100 in the total number, were collected from different laboratories in Tehran, Iran and tested for anti-Toxoplasma specific IgG and IgM antibodies using indirect immunofluorescent antibody test (IFAT). Using the IgG (chronic) and IgM (acute) positive samples, the IgG avidity test was performed by ELISA in duplicate rows of 96-well microtiter plates. One row was washed with 6 M urea and the other with PBS (pH 7.2), then the avidity index (AI) was calculated. Sixteen out of 18 (88.9%) sera with acute toxoplasmosis showed low avidity levels (AI60). Six sera had borderline ranges of AI. The results showed that the IgG avidity test by ELISA could distinguish the acute and chronic stages of toxoplasmosis in humans.
Subject(s)
Humans , Antibodies, Protozoan/blood , Antibody Affinity , Clinical Laboratory Techniques/methods , Enzyme-Linked Immunosorbent Assay/methods , Fluorescent Antibody Technique, Indirect , Immunoglobulin G/blood , Immunoglobulin M/blood , Iran , Parasitology/methods , Toxoplasmosis/diagnosisABSTRACT
Serum samples, 100 in the total number, were collected from different laboratories in Tehran, Iran and tested for anti-Toxoplasma specific IgG and IgM antibodies using indirect immunofluorescent antibody test (IFAT). Using the IgG (chronic) and IgM (acute) positive samples, the IgG avidity test was performed by ELISA in duplicate rows of 96-well microtiter plates. One row was washed with 6 M urea and the other with PBS (pH 7.2), then the avidity index (AI) was calculated. Sixteen out of 18 (88.9%) sera with acute toxoplasmosis showed low avidity levels (AI60). Six sera had borderline ranges of AI. The results showed that the IgG avidity test by ELISA could distinguish the acute and chronic stages of toxoplasmosis in humans.