Evaluation of ELISA and dot blots for the serodiagnosis of neurocysticercosis, in children found to have single or multiple enhancing lesions in computerized tomographic scans of the brain

Abstract

Although human neurocysticercosis (NCC) is being increasingly recognized in children, diagnosis of the disease can be difficult, and the 'gold standard' criteria that indicate an unambiguous case have still to be established. In the present study, the performances of an ELISA and dot-blot assay, for the detection of antibodies against antigens from larval Taenia solium, were investigated and compared, using sera, from children aged 5-12 years, that were diluted to at least 1:400. Eighty of the subjects (20 aged 5-<8 years and 60 older children) each had the signs and symptoms of NCC, including one brain lesion (N=69) or multiple brain lesions (N=11) that were visible by computed tomography. Another 100 sera, from children who had tubercular meningitis (N=20) or a parasitic disease other than taeniasis/cysticercosis (N=20) or, apart from a minor respiratory-tract infection, appeared healthy (N=60), were also investigated. Most (86%) of the cases of NCC had presented with focal seizures. Analysis of antibody response indicated that the optimum threshold titres for seropositivity were 1:800 for the ELISA and 1:6400 for the dot-blot assays. When used with these thresholds, the ELISA gave a sensitivity, specificity, positive and negative predictive values and diagnostic efficacy of 89%, 81%, 79%, 90%, 85%, respectively. The corresponding values for the dot-blot assay were similar, at 89%, 73%, 72.5%, 89%, 82%, respectively. Both assays were more sensitive, in the detection of the specific antibody response, when used among the paediatric cases of NCC who had multiple brain lesions (100%) than when used among the single-lesion cases (87%). As the ELISA gave higher specificity and diagnostic efficacy than the dot-blot assay, it should be considered the better method for the serological confirmation of NCC in children.

Utility of cysticercus fasciolaris antigen in Dot ELISA for the diagnosis of neurocysticercosis

“…Both tests gave similar sensitivity, viz., 89%; while ELISA had better specifi city, viz., 81%, than Dot Blot (73%). [17] In another study by Biswas et al, Dot-ELISA was found to be 56.25% sensitive and 92% specifi c, as compared to plate ELISA, which was 43.75% sensitive and 98% specifi c. [12] Jiang et al have observed confi rmed cases of neurocysticercosis showing 81.6% to 96.1% positive reactions in Dot-ELISA. [11] It is reported that sensitivity and specifi city of Dot ELISA generally vary from 56.25% to 97.61% and from 90.6% to 92% respectively.…”

Evaluation of lower molecular mass (20–24 kDa) Taenia solium cysticercus antigen fraction by ELISA and dot blot for the serodiagnosis of neurocysticercosis in children

“…solium cysticerci crude soluble extract (CSE) antigen was prepared (Kaur et al 1996;Mandal et al 2006) and subjected to SDS-PAGE (Lamelli 1970). Antigenic fraction corresponding to standard molecular mass marker fraction of 20-24 kDa was eluted out (Plancarte et al 1994) from the gel by an electro eluter (BIORAD Inc., USA).…”

“…Nearly two-thirds of the Indian patients have single lesion disease, therefore, there is need to identify the serodiagnostic tests with high sensitivity and specificity which can detect single lesion disease as well as multilesion disease with equal efficacy and high specificity (Rajshekhar and Chandy 1997;Prabhakar et al 2004). The present study was aimed to evaluate the efficacy of Tso cysticercus LMM antigen fraction (20-24 kDa) by ELISA and dot blot for the diagnosis of NCC in children and to compare the results of the present study with our previous study conducted in the same samples with the use of crude soluble extract (CSE) antigen (Mandal et al 2006). An attempt was also made to correlate the results of antibody response with radiological findings (single vs. multiple lesions).…”

“…A battery of highly sensitive immunodiagnostic techniques have been applied to detect specific antibody response in NCC patients. Taenia solium (Tso) cysticerci crude antigen and antigen B have frequently led to low specificity due to cross reactions (Espinoza et al 1986;Estrada et al 1989;Katti and Chandramukhi 1991;Malla et al 1992;Das et al 2002;Mandal et al 2006) and use of lower molecular mass (LMM) antigen fractions are reported to have high specificity (Grogl et al 1985;Gottstein et al 1986;Tsang et al 1989;Kaur et al 1995;Kaur et al 1996;Lissiane et al 1999)). In our earlier study, in adults, detection of antibody response to LMM antigen fraction (20-24 kDa) of Tso cysticerci, by ELISA had shown a sensitivity and specificity of 95.23% and 100%, respectively (Kaur et al 1996).…”

Extraparenchymal Neurocysticercosis

“…The sensitivity was less for single lesions (52)and for calcified lesions (2;2;53-56). A comparative study of enzyme-linked immunosorbent assay (ELISA) and dotblot assay in children found that both were more sensitive in cases with multiple brain lesions (100%) than in those with a single lesion (87%) (5). The sensitivity of antibody detecting EITB assays is not better with the use of CSF samples as compared with serum samples (55).…”