Application of synthetic 8-kD and recombinant GP50 antigens in the diagnosis of neurocysticercosis by enzyme-linked immunosorbent assay.

The gold standard serodiagnostic assay for cysticercosis and neurocysticercosis, diseases caused by the metacestode of Taenia solium, uses lentil lectin-purified glycoprotein (LLGP) in a Western blot assay. We tested two antigens derived from LLGP, synthetic TS18var1 (sTS18var1) and recombinant GP50 antigen (rGP50), in an enzyme-linked immunosorbent assay (ELISA) using serum and cerebrospinal fluid (CSF) samples. The sensitivity for serum and CSF was 94.7% and 100% for rGP50 and 90.4% and 90.2% for sTS18var1, respectively. The specificity for serum and CSF samples was 93.8% and 100% for rGP50 and 90.3% and 98.0% for sTS18var1, respectively. The use of these antigens individually or combined as a diagnostic antigen cocktail eliminates the need for purification of antigens from parasite material and offers the advantage of using a simple and quantitative ELISA format.

Frequency of serum anti-cysticercus antibodies in the population of a rural Brazilian community (Cássia dos coqueiros, SP) determined by Elisa and immunoblotting using Taenia crassiceps antigens.

Considering the impact of cysticercosis on public health, especially the neurologic form of the disease, neurocysticercosis (NC), we studied the frequency of positivity of anti-Taenia solium cysticercus antibodies in serum samples from 1,863 inhabitants of Cássia dos Coqueiros, SP, a municipal district located 80 km from Ribeirão Preto, an area considered endemic for cysticercosis. The 1,863 samples were tested by enzyme linked immunosorbent assay (ELISA) using an antigenic extract from Taenia crassiceps vesicular fluid (Tcra). The reactive and inconclusive ELISA samples were tested by immunoblotting. Of the 459 samples submitted to immunoblotting, 40 were strongly immunoreactive to the immunodominant 18 and 14 kD peptides. Considering the use of immunoblotting as confirmatory due to its high specificity, the anti-cysticercus serum prevalence in this population was 2.1%.

IgG intrathecal synthesis and specific antibody index in patients with neurocysticercosis.

UNLABELLED: We analyzed cerebrospinal fluid (CSF) and blood serum from 55 patients with neurocysticercosis (NC) at different clinical stages. According to inflammatory activity in the CSF, three stages were identified: (1) reactive, when there was at least an increase in the number of cells; (2) weakly reactive, when significant alterations were found in the CSF, including an increase in gamma globulins, albeit without hypercytosis; (3) non-reactive, when there was neither hypercytosis nor increase in gamma globulins. Nineteen patients had the reactive form; 18 had the weakly reactive form; 18 displayed the non-reactive form. Local immunoproduction was intense in the reactive group, moderate in the weakly reactive group, and absent in the non-reactive group. The specific antibody index was raised in approximately 2/3 of patients with the reactive form, 2/3 in those with the weakly reactive form, and 1/3 in those with the non-reactive form. IN CONCLUSION: (1) the classical CSF syndrome in NC can present both in complete and partial modes; (2) local immunoproduction can occur in weakly reactive forms; (3) a raised specific antibody index can occur in the absence of an inflammatory reaction in the CSF.

Development of a normal human immunoglobulin G standard curve for enzyme-linked immunosorbent assay: use for comparison of antigen efficacy.

Internal standard reference curves are used in enzyme-linked immunosorbent assay (ELISA) plates to control for inter- and intra-assay variance. To compare the diagnostic potential of multiple T. solium antigens on an unbiased, universal scale, we have created a standard curve using normal, human immunoglobulin G (hIgG). The hIgG curve is inexpensive and simple to prepare, and remains stable at 5 degrees C for at least one year, with a coefficient of variance of less than 10%. The hIgG standard curve has proven a critical tool for the comparison of several diagnostic antigens slated for assay development.

Frequency of serum anti-cysticercus antibodies in the population of a rural Brazilian community (Cassia dos Coqueiros, SP) determined by ELISA and immunoblotting using Taenia crassiceps antigens

Considering the impact of cysticercosis on public health, especially the neurologic form of the disease, neurocysticercosis (NC), we studied the frequency of positivity of anti-Taenia solium cysticercus antibodies in serum samples from 1,863 inhabitants of Cássia dos Coqueiros, SP, a municipal district located 80 km from Ribeiräo Preto, an area considered endemic for cysticercosis. The 1,863 samples were tested by enzyme linked immunosorbent assay (ELISA) using an antigenic extract from Taenia crassiceps vesicular fluid (Tcra). The reactive and inconclusive ELISA samples were tested by immunoblotting. Of the 459 samples submitted to immunoblotting, 40 were strongly immunoreactive to the immunodominant 18 and 14 kD peptides. Considering the use of immunoblotting as confirmatory due to its high specificity, the anti-cysticercus serum prevalence in this population was 2.1 percent

IgG intrathecal synthesis and specific antibody index in patients with neurocysticercosis

We analyzed cerebrospinal fluid (CSF) and blood serum from 55 patients with neurocysticercosis (NC) at different clinical stages. According to inflammatory activity in the CSF, three stages were identified: (1) reactive, when there was at least an increase in the number of cells; (2) weakly reactive, when significant alterations were found in the CSF, including an increase in gamma globulins, albeit without hypercytosis; (3) non-reactive, when there was neither hypercytosis nor increase in gamma globulins. Nineteen patients had the reactive form; 18 had the weakly reactive form; 18 displayed the non-reactive form. Local immunoproduction was intense in the reactive group, moderate in the weakly reactive group, and absent in the non-reactive group. The specific antibody index was raised in approximately 2/3 of patients with the reactive form, 2/3 in those with the weakly reactive form, and 1/3 in those with the non-reactive form. In conclusion: (1) the classical CSF syndrome in NC can present both in complete and partial modes; (2) local immunoproduction can occur in weakly reactive forms; (3) a raised specific antibody index can occur in the absence of an inflammatory reaction in the CSF