[Ventriculo-lumbar gradient of concentration of total cerebrospinal fluid proteins: 1 - mechanisms of origin]

Immunological and molecular diagnosis of cysticercosis

Cysticercosis, the infection with the larval stage of Taenia solium, is a cause of neurological symptoms including seizures, affecting the quality of life of patients and their families. Diagnosis focuses on brain imaging and serological tests are mostly used as confirmatory tools. Most cases, however, occur in poor endemic areas, where both kinds of diagnostic tools are poorly available. Development of point of care diagnostic tests is one of the most important priorities for cysticercosis researches today. The ideal point of care test would require detection of viable cysticercosis and hopefully identify cases with severe or progressive forms of neurocysticercosis, leading to referral of the patient for specialized medical attention. This manuscript describes the evolution of the serological diagnosis of cysticercosis over time, and the characteristics of the most common currently available tools, their advantages and disadvantages, and their potential use in future diagnostic tests.

Detection of Taenia solium antigens and anti-T. solium antibodies in paired serum and cerebrospinal fluid samples from patients with intraparenchymal or extraparenchymal neurocysticercosis

BACKGROUND

Neurocysticercosis (NCC) is a frequent cause of epilepsy worldwide. Compared with the more common parenchymal brain cysts, extraparenchymal infections are difficult to manage and have a poor prognosis. Serological assays are used to detect circulating Taenia solium antigens or anti-T. solium antibodies in serum or cerebrospinal fluid (CSF) samples. There are no guidelines on whether to use serum or CSF specimens for a particular assay.

METHODS

We obtained paired serum and CSF samples from 91 patients with NCC (48 had intraparenchymal NCC, and 43 had extraparenchymal NCC) for detection of antibodies, using an enzyme-linked immunotransfer blot (EITB) assay, and antigens, using a monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA).

RESULTS

For the intraparenchymal NCC group, the EITB assay yielded more true-positive results for serum samples, and the ELISA yielded slightly more true-positive results for CSF samples than for serum samples, but none of these differences were statistically significant. Most patients with calcified NCC were antibody positive but antigen negative. For extraparenchymal disease, all samples were antibody positive, and all but 2 were antigen positive, with most samples containing high antigen levels.

CONCLUSIONS

The sensitivity of antibody-detecting EITB assays is not increased through the use of CSF samples rather than serum samples. The antigen-detecting ELISA performed better for CSF samples than for serum samples, but for both specimen types it was less sensitive than the EITB assay. Active and inactive NCC are better differentiated from each other by the antigen-detecting ELISA, for both serum and CSF samples. High antigen levels suggest the presence of subarachnoid NCC.

[Ventriculo-lumbar gradient of concentration of total cerebrospinal fluid proteins: 2.- Influence of CSF drainage by ventriculoatrial shunt]

On a previous paper, based upon the data obtained from comparative studies of cerebrospinal fluid samples of two groups of patients with neurocysticercosis in activity, one with patency, the other one with blockage of the spinal subarachnoid space, evidence was presented that the concentration gradient of proteins along the neuraxis was the consequence of the escape of water from cerebrospinal fluid. The second paper is a continuance of that one. The material for this survey consisted of the clinical records of 11 patients with neurocysticercosis who during the course of the disease presented severe intracranial hypertension which required ventriculoatrial shunt as an emergency operation in order to allow survival. After surgery, it was observed a marked improvement in the clinical picture. Later, it was noticed a large increase in the protein content of the spinal fluid of the majority of the patients, as compared with the results verified prior to surgery. However, in these spinal fluid samples the increase in protein content was observed without a simultaneous rise in cell count, suggesting an improvement in the inflammatory condition. It seems very likely that this large elevation of the protein content in the subarachnoid fluid is the consequence of a reduction in the spinal fluid flow rate due to the ventricle-venous shunt.(ABSTRACT TRUNCATED AT 250 WORDS)