Evaluation of enzyme-linked immunosorbent assay in serological diagnosis of human neurocysticercosis using paired samples of serum and cerebrospinal fluid

Abstract

The applicability of micro-ELISA was evaluatd in human neuro-cysticercosis using paired samples of serum and CSF. A total of 355 cases who were mostly neurologic patients was subjected. Cystic fluid of C. cellulosae was used as antigen in protein concentration of 2.5 micro-g/ml. Serum was diluted to 1:100 and CSF was undiluted in the assay for the specific IgG antibody level. The differential criterion of the positive reaction was the abs. of 0.18 in both samples. The results were summarized as follows: The overall sensitivity of the micro-ELISA in 71 confirmed neurocysticercosis was 90.1%; the sensitivity by serum was 77.5% and that by CSF was 83.1%. CSF was a more sensitive and valuable material. Most of the false negative cases of neuro-cysticercosis showed far lower level of abs. rather than marginal. The overall specificity of the micro-ELISA in 52 confirmed other neurologic diseases was 88.5%; the specificities by serum and by CSF were 94.2% respectively. Cases of other neurologic diseases did not show false positive reactions in both samples. When serum was assayed, taeniasis(2/18), sparganosis(2/20), paragonimiasis(1/56), clonorchiasis(1/15) and fascioliasis(1/1) cases showed cross reactions. When CSF was assayed, 2 of 10 neuro-sparganosis showed cross reactions while none of 9 neuro-paragonimiasis showed it. Out of 71 confirmed neuro-cysticercosis cases, 6 and 11 showed cross reactions by serum and CSF to crude extract antigen of sparganum; but no case did show it to crude extract antigen of Paragonimus westermani. Ventricular CSF showed low or negative levels of IgG antibody than lumbar CSF unless the lesion was at the lateral ventricle itself. Out of 4 racemose cysticercosis cases, 3 showed positive reaction in serum while all of 3 examined CSF were positive. The above results indicated that the serological test for detecting the specific IgG antibody by micro-ELISA using paired samples of serum and CSF was very helpful for clinical differentiation of neuro-cysticercosis from neurologic diseases of other causes.

Detection ofTaenia soliumAntigens and Anti–T. soliumAntibodies in Paired Serum and Cerebrospinal Fluid Samples from Patients with Intraparenchymal or Extraparenchymal Neurocysticercosis

“…“De novo” immunoglobulin synthesis inside the central nervous system has been shown to occur in NCC [17]. In general, however, antibody levels are lower in CSF, because they mostly come from passive diffusion from the blood system [29, 30], although there is a gradient of increased protein concentration as the CSF descends along the neuroaxis [30, 31]. Consequently, the use of CSF yields weaker reactions and thus lower sensitivity but also a significant reduction in nonspecific reactions.…”

“…Consequently, the use of CSF yields weaker reactions and thus lower sensitivity but also a significant reduction in nonspecific reactions. Thus, for assay formats of lower specificity, such as indirect hemagglutination, complement fixation, or ELISA using nonpurified antigens, test performance is improved by using CSF instead of serum [31–35]. Highly specific assays can take advantage of the stronger reactivity of serum without the risk of disturbing increases in false-positive results [9, 15, 36–39].…”

Can Pleuropulmonary Paragonimiasis be Cured by Only the 1st Set of Chemotherapy? Treatment Outcome and Clinical Features of Recently Developed Pleuropulmonary Paragonimiasis

“…A systemic review of the chest radiographs or CT scans was also performed for all patients. A serologic test for Paragonimus westermani parasite-specific IgG by using micro-enzyme linked immunosorbent assay (ELISA for PW) (14,15) was used for the routine primary screening of parasitic disease.…”

Immunological and molecular diagnosis of cysticercosis

“…A proportion of these cases could also correspond to early lesions, caused by cysticerci, that resolved soon after infection, before full establishment and thus not provoking a strong immune response. 172 Most seronegative NCC cases in ELISA 111 or in the LLGP-EITB 48,50,51 correspond to cases with a single lesion, although the estimates of sensitivity of the assays in this type of NCC vary greatly. Prabhakaran et al reported an increase in sensitivity following the use of urea to expose the tertiary structure of the antigenic glycoproteins, detecting 46% of previously negative cases in EITB.…”