Serodiagnosis of cysticercosis by ELISA-inhibition test using monoclonal antibodies

Serological and molecular detection of neurocysticercosis among epileptic patients in Nagpur, Maharashtra state (India)

Neurocysticercosis (NCC), one of the most important neuroparasitic diseases in humans, is caused by Cysticercus cellulosae, the metacestode stage of digenetic zoonotic cestode Taenia solium. The present study aims at the detection of anti-cysticercus antibodies in the sera of epileptic patients (n=26) visiting a tertiary care hospital in Nagpur, Maharashtra state, India, by an in-house developed indirect IgG-ELISA and enzyme-linked immunoelectro transfer blot (EITB) assay using different antigens (namely, Whole Cyst Antigen (WCA), Cystic Fluid Antigen (CFA), Scolex Antigen (SA), Excretory-Secretory Antigen (ESA) and Membrane-Body Antigen (MBA)) prepared from T. solium metacestodes to find out the status of NCC. An attempt has also been made for molecular detection of NCC from blood samples of those patients by Polymerase Chain Reaction (PCR) assay targeted at large subunit rRNA gene of T. solium. The IgG ELISA level of anti-cysticercus antibodies against WCA, CFA, SA, ESA and MBA antigens were as follows: 19.23 %, 23.07 %, 38.46 %, 30.76 % and 15.38 %. The seroreactivity to CFA, SA and ESA was found in equal proportions in patients with ring-enhancing lesions. In the EITB assay, the lower and medium molecular weight protein bands of SA and ESA were immunodominant compared to the higher WCA and CFA peptides. PCR positivity could be observed in 34.6 % (9/26) of the patients under study. It is the first report of detecting NCC among epileptic patients of the Nagpur region of Maharashtra state in India using serological and molecular tools.

Cysticercus cellulosae antigens in the serodiagnosis of neurocysticercosis

Neurocysticercosis (NCC) is difficult to diagnose clinically because of its varied clinical presentation. However, an accurate diagnosis is possible only after suspicion on epidemiological grounds, proper interpretation of the clinical data, analysis of the findings on imaging studies, and specific immunological tests on the serum and cerebrospinal fluid (CSF). The diagnosis of NCC by any single parameter thus continues to remain difficult. In the past, detection of NCC was based on autopsy studies and histological confirmation. In recent times, the advent of imaging methods such as computed tomography and magnetic resonance imaging have provided excellent non-invasive tools for easy detection of NCC. Nevertheless, an imaging technique of the brain, although useful, is not considered as a gold standard for the diagnosis of NCC. Serological tests are being increasingly used in adjunct with imaging techniques, to aid the diagnosis of NCC. Immunodiagnostic techniques include detection methods for specific antibodies and for circulating parasite antigens in the serum and CSF. Currently, many of the immunodiagnostic tests, including the enzyme-linked immunosorbent assay and enzyme immunotransfer blot, use purified native antigens for the immunodiagnosis of NCC. Nevertheless, the main problem with the use of native cysticercal antigens is that the native proteins often show cross reactions with sera from humans infected with other parasites. The preparation of native antigens also demand a constant supply of parasitic material from the intermediate host pig. In order to overcome the problems in using native antigens, the recombinant antigens or synthetic peptides, which can be produced under stable conditions, are being evaluated for the serodiagnosis of NCC.

A case of extensive spinal cysticercosis involving the whole spinal canal in a patient with a history of cerebral cysticercosis

Although cysticercosis is the most common parasitic disease affecting the central nervous system, spinal cysticercosis is rare. A rare form of spinal cysticercosis involving the whole spinal canal is presented. A 45-year-old Korean male had a history of intracranial cysticercosis and showed progressive paraparesis. Spinal magnetic resonance scan showed multiple cysts compressing the spinal cord from C1 to L1. Three different levels (C1-2, T1-3, and T11-L1) required operation. Histopathological examination confirmed cysticercosis. The patient improved markedly after surgery.