Anticysticercous antibodies in serum and cerebrospinal fluid in patients with cerebral cysticercosis

Analysis of cerebrospinal fluid in racemose form of neurocysticercosis

The present work aimed to evaluate the pattern of CSF alterations in patients diagnosed with neurocysticercosis (NCC) in racemose form.Method This is a retrospective cohort study of patients with diagnosis of NCC in racemose form. CSF samples from 26 patients were analyzed. After patient-chart analysis was performed descriptive analysis of case studies and comparison between sexes in relation to variables were obtained with CSF by Mann-Whitney and Student's t-tests.Results The sexes did not differ statistically when compared to pleocytosis in CSF. Eosinophils were present in 31% in samples while the ELISA test presented 80% sensitivity in this case series. Of the patient total, 24 presented a meningitis pattern with lymphocytic predominance.Conclusion There was no difference in inflammatory pattern between the sexes, with predominance of lymphocytic meningitis and 80% sensitivity by ELISA test of CSF patients with racemose form of NCC.

Free-GABA levels in the cerebrospinal fluid of patients suffering from several neurological diseases Its potential use for the diagnosis of diseases which course with inflammation and tissular necrosis

Free GABA levels were measured in the cerebrospinal fluid (CSF) of 74 neurological patients suffering from cerebral cysticercosis (n = 9), Parkinson's disease (n = 5), multiple sclerosis (n = 6), epilepsy (n = 24), meningeal tuberculosis (n = 6), viral encephalitis (n = 3), cerebrovascular disease (n = 8) and several kinds of dystonia (n = 5). A statistical significant four-fold elevation in free GABA levels was found in patients with cerebral cysticercosis. A non statistical significant two-fold increase in free GABA levels was also encountered in the CSF of patients affected by cerebrovascular disease and viral encephalitis. No changes in CSF free GABA levels were found in patients suffering from any of the other disorders. It is suggested that free GABA levels may be elevated in the CSF of patients suffering from neurological diseases which course with inflammation and tissular necrosis such as cerebral cysticercosis. Much work is needed however to establishd whether CSF free GABA levels can be used as a diagnostic tool in at least some type of these patients.

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.

Immunodiagnosis of neurocysticercosis: ways to focus on the challenge

Neurocysticercosis (NCC) is a disease of the central nervous system that is considered a public health problem in endemic areas. The definitive diagnosis of this disease is made using a combination of tools that include imaging of the brain and immunodiagnostic tests, but the facilities for performing them are usually not available in endemic areas. The immunodiagnosis of NCC is a useful tool that can provide important information on whether a patient is infected or not, but it presents many drawbacks as not all infected patients can be detected. These tests rely on purified or semipurified antigens that are sometimes difficult to prepare. Recent efforts have focused on the production of recombinant or synthetic antigens for the immunodiagnosis of NCC and interesting studies propose the use of new elements as nanobodies for diagnostic purposes. However, an immunodiagnostic test that can be considered as "gold standard" has not been developed so far. The complex nature of cysticercotic disease and the simplicity of common immunological assumptions involved explain the low scores and reproducibility of immunotests in the diagnosis of NCC. Here, the most important efforts for developing an immunodiagnostic test of NCC are listed and discussed. A more punctilious strategy based on the design of panels of confirmed positive and negative samples, the use of blind tests, and a worldwide effort is proposed in order to develop an immunodiagnostic test that can provide comparable results. The identification of a set of specific and representative antigens of T. solium and a thorough compilation of the many forms of antibody response of humans to the many forms of T. solium disease are also stressed as necessary.

Human neurocysticercosis: comparison of different diagnostic tests using cerebrospinal fluid

Neurocysticercosis (NC), caused by the larval stage of Taenia solium, is one of the most common parasitic diseases of the central nervous system. The diagnosis of NC is mostly based on costly brain neuroimaging (computed tomography and/or nuclear magnetic resonance), which is rarely accessible in most affected areas. The most sensitive and specific tools for NC diagnosis are imagery techniques. The identification of specific antibodies and antigens is currently used only to support NC diagnosis due to their limited specificity and sensitivity. This study was performed to compare immunodiagnostic assays (antibody detection by enzyme-linked immunosorbent assay [ELISA] and enzyme-linked immunoelectrotransfer blotting [EITB] and HP10 antigen detection by ELISA) with the detection of parasite DNA by PCR amplification of a repetitive element of the parasite genome in the cerebrospinal fluid (CSF) of 121 radiologically and clinically characterized NC patients. Patients were divided into six groups according to the stage of the parasites and their localization. The CSF cellularity of each patient was also recorded. When all patients were considered, PCR exhibited the highest sensitivity (95.9%) and variable specificity (80% or 100%) depending on the controls used. The sensitivities of antibody detection by ELISA and EITB were not significantly different, and ELISA identified HP10 antigen mostly when vesicular cysticerci were located in the subarachnoideal basal cisterns. These results can help in the selection of different individual assays or combinations of assays to be used in NC diagnosis according to different requirements.

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.

Human cysticercosis and Indian scenario: a review

Cysticercosis, caused by Taenia solium larva is a major public health problem,especially in the developing world and neurocysticercosis (NCC) is considered to be the most common parasitic infestation of the central nervous system. NCC is identified as the single most common cause of community acquired active epilepsy; 26.3% to 53.8% active epilepsy cases in the developing world including India and Latin America are due to NCC.It is also becoming more common in the developed world because of increased migration of people with the disease or Taenia solium carriers and frequent travel to the endemic countries. It is estimated that three quarters of the estimated 50 million people with active epilepsy live in the poor countries of the world. Recent Indian studies using neuroimaging techniques suggest that the disease burden in India surpasses many other developing countries. Hence it is important to know the epidemiology,pathogenesis and diagnostic criteria so as to assess the disease burden and adopt interventional strategies for its control.Literature search was done for this review with special emphasis on Indian studies to create awareness about the disease in India,since cysticercosis is preventable and potentially eradicable.

Evaluation of intrathecal synthesis of IgG in neurocysticercosis

Neurocysticercosis is a world public health problem. An increase in immunoglobulin G (IgG) concentration in the cerebrospinal fluid of patients with neurocysticercosis has been described but the reasons for this finding are unknown. Our hypothesis is that the increase in IgG concentration in cerebrospinal fluid is due to exclusive intrathecal synthesis of IgG and this process is associated with the inflammatory phases of the disease. We studied IgG concentration in cerebrospinal fluid in 16 patients with neurocysticercosis comparing with a control group of 19 patients to verify which pattern of increase in IgG concentration in cerebrospinal fluid occurs in neurocysticercosis. In the neurocysticercosis group, intrathecal synthesis of IgG was detected in 12 (75%) and 5 (31.2%) patients by quantitative and qualitative methods, respectively. When compared with the control group the neurocysticercosis patients had the same pattern of intrathecal synthesis of IgG as multiple sclerosis patients. Intrathecal synthesis of IgG was not associated with any variable indicative of an inflammatory process. We conclude that the increase in IgG concentration in neurocysticercosis is due to intrathecal synthesis, as is also the case for multiple sclerosis, and that this process is not related to the inflammatory stage of NCC.

Neurocysticercosis: a review

BACKGROUND

In North America, the largest number of neurosurgical cases stemming from parasitic infections involves the larval form of Taenia solium, the infectious organism causing neurocysticercosis. This infection of the central nervous system (CNS) is most commonly seen in areas with significant immigrant populations and can often present particular challenges to treating physicians.

METHODS

A review of the literature was performed, highlighting the epidemiology, parasitology, and clinical manifestations of neurocysticercosis. Particular attention was paid to 4 locations of neurocysticercosis lesions: parenchymal, subarachnoid/cisternal, intraventricular, and spinal.

RESULTS

Both medical and surgical interventions may be necessary for adequate treatment of neurocysticercosis, depending on various factors, including location of lesion.

CONCLUSIONS

A review of neurocysticercosis, with particular attention paid to location of disease involvement in the CNS, provides important information to the clinical management of this disease.

Current consensus guidelines for treatment of neurocysticercosis

Taenia solium neurocysticercosis is a common cause of epileptic seizures and other neurological morbidity in most developing countries. It is also an increasingly common diagnosis in industrialized countries because of immigration from areas where it is endemic. Its clinical manifestations are highly variable and depend on the number, stage, and size of the lesions and the host's immune response. In part due to this variability, major discrepancies exist in the treatment of neurocysticercosis. A panel of experts in taeniasis/cysticercosis discussed the evidence on treatment of neurocysticercosis for each clinical presentation, and we present the panel's consensus and areas of disagreement. Overall, four general recommendations were made: (i) individualize therapeutic decisions, including whether to use antiparasitic drugs, based on the number, location, and viability of the parasites within the nervous system; (ii) actively manage growing cysticerci either with antiparasitic drugs or surgical excision; (iii) prioritize the management of intracranial hypertension secondary to neurocysticercosis before considering any other form of therapy; and (iv) manage seizures as done for seizures due to other causes of secondary seizures (remote symptomatic seizures) because they are due to an organic focus that has been present for a long time.

Imaging features and surgery-related outcomes in intraventricular neurocysticercosis

Object

Neurocysticercosis (NCC) is the most common parasitic infection of the central nervous system, and its prevalence is continuing to increase in the United States. The diagnosis of intraventricular NCC (IVNCC) may be difficult, and surgery frequently fails to resolve symptoms. A retrospective review of magnetic resonance (MR) imaging characteristics and surgery-related outcomes may improve management strategies of this disease.

Methods

The authors report the presentations, neuroimaging characteristics, surgical management, and outcomes of 30 patients with IVNCC treated over a 10-year period (mean follow-up period 4 years). Cysts were located in the lateral ventricles (five cases), the third ventricle (five cases), and the fourth ventricle (21 cases). One patient had lesions in both the lateral and fourth ventricles. Presenting symptoms were related to hydrocephalus or mass effect from the lesions.

All patients underwent computerized tomography (CT) and MR imaging of the brain. Treatment consisted of shunt implantation or primary excision of an IVNCC lesion. Outcomes after operations and reoperations were evaluated in light of enhancement characteristics on MR imaging.

Computerized tomography scanning demonstrated IVNCC lesions in 10% of cases, and MR revealed lesions in 100% of cases. In patients in whom gadolinium (Gd) enhancement of IVNCC lesions was demonstrated on MR imaging, the surgery-related failure rate was higher and patients required reoperation, and in those in whom gadolinium enhancement was absent the surgery-related failure rate was lower (64 and 19%, respectively; p < 0.0002).

Conclusions

Magnetic resonance imaging is superior to CT scanning for detecting IVNCC lesions. The absence of pericystic Gd enhancement on MR imaging is an indication for excision of the lesions. If pericystic enhancement is present, shunt surgery should be performed, and craniotomy reserved for treatment of those patients with symptomatic lesions secondary to mass effect. A treatment algorithm based on patient symptoms, cyst location, and MR imaging Gd enhancement characteristics is proposed.

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%.

Proposed diagnostic criteria for neurocysticercosis

Neurocysticercosis is the most common helminthic infection of the CNS but its diagnosis remains difficult. Clinical manifestations are nonspecific, most neuroimaging findings are not pathognomonic, and some serologic tests have low sensitivity and specificity. The authors provide diagnostic criteria for neurocysticercosis based on objective clinical, imaging, immunologic, and epidemiologic data. These include four categories of criteria stratified on the basis of their diagnostic strength, including the following: 1) absolute--histologic demonstration of the parasite from biopsy of a brain or spinal cord lesion, cystic lesions showing the scolex on CT or MRI, and direct visualization of subretinal parasites by funduscopic examination; 2) major--lesions highly suggestive of neurocysticercosis on neuroimaging studies, positive serum enzyme-linked immunoelectrotransfer blot for the detection of anticysticercal antibodies, resolution of intracranial cystic lesions after therapy with albendazole or praziquantel, and spontaneous resolution of small single enhancing lesions; 3) minor--lesions compatible with neurocysticercosis on neuroimaging studies, clinical manifestations suggestive of neurocysticercosis, positive CSF enzyme-linked immunosorbent assay for detection of anticysticercal antibodies or cysticercal antigens, and cysticercosis outside the CNS; and 4) epidemiologic--evidence of a household contact with Taenia solium infection, individuals coming from or living in an area where cysticercosis is endemic, and history of frequent travel to disease-endemic areas. Interpretation of these criteria permits two degrees of diagnostic certainty: 1) definitive diagnosis, in patients who have one absolute criterion or in those who have two major plus one minor and one epidemiologic criterion; and 2) probable diagnosis, in patients who have one major plus two minor criteria, in those who have one major plus one minor and one epidemiologic criterion, and in those who have three minor plus one epidemiologic criterion.

Lack of association between parenchymal neurocysticercosis and HLA Class I and Class II antigens

Neurocysticercosis, caused by encysted larvae of the tapeworm Taenia solium, is the most common infection of the central nervous system and a major public health problem in many countries. Prevalence in the region of Curitiba, located in the southern Brazilian State of Paraná, is one of the highest in the world. The genetics of host susceptibility to neurocysticercosis (NCC) is still obscure. To investigate if major histocompatibility complex (MHC) genes influence individual susceptibility to NCC, we performed a case-control association analysis. Fifty-two Caucasoid patients and 149 matched controls were typed for antigens of the HLA-A, B, C, DR and DQ loci. All patients had computerized tomography and clinical features compatible with parenchymal NCC. Indirect immunofluorescence of cerebrospinal fluid showed that 19 (37%) of the patients presented anti-cysticercus antibodies at titers <FONT FACE="Symbol">³</font> 1:10. Frequencies of HLA specificities in the whole group of patients and in the subgroup with antibodies in cerebrospinal fluid were compared to those of the control group. No significant difference was found. These results do not support the hypothesis of HLA gene participation in susceptibility to parenchymal neurocysticercosis.

Measurement of magnetization transfer in different stages of neurocysticercosis

The purpose of this study was to establish magnetization transfer ratio (MTR) in different stages of neurocysticercosis. A total 2,532 cysticerci were studied prospectively in 15 cases. MTR from different regions of the lesions (ie, the cyst, the protoscolex or mural nodule, the granuloma wall) were calculated in different stages of evolution/degeneration in all cases. Of a total 2,532 lesions studied, 2,261 (89.29%) were seen on routine spin-echo (SE) imaging. The rest of the lesions were only seen on magnetization transfer (MT) SE imaging. Maximum MTR was calculated from healing lesions (mean + SD = 31.0+/-2.8) and from the core of SE invisible lesions (30.0+/-5.1). Innocuous cystic lesions, which were hyperintense on T2-weighted images, did not show any MT (MTR = 5.10+/-1.2), whereas degenerating T2 hyperintense lesions showed MTR of 26.40+/-2.7. Nondegenerating and degenerating scolices showed an intermediate MTR of 21.7+/-3.3 and 15.0+/-4.5, respectively. MT varies between different parts of the lesion and also from the same part in different stages of evolution/degeneration of the lesion. The visibility of a lesion on MT-SE sequence was dependent on its MTR and its location at a particular site (cortical gray matter, white matter, or deep gray matter). The difference in MTR of the lesion and the surrounding brain parenchyma decides the resulting contrast and visibility of the lesion.

Neurocysticercosis

Cysticercosis is an infection caused by Taenia solium larvae (cysticerci). When the cysticercus is lodged in the central nervous system (CNS), the disease is known as neurocysticercosis (NCC). NCC is the most frequent and most widely disseminated human neuroparasitosis. It is endemic in many parts of the world, particularly Latin America, Africa, and Asia, and still relatively frequent in Portugal, Spain and Eastern European countries It is also endemic in developed countries with high rates of immigration from endemic areas. Man may act as an intermediate host after ingestion of mature, viable T. solium eggs via the fecal-oral route. The development of lesions in the brain and leptomeninges, and the consequent of onset of symptoms associated with NCC are mainly due to the host immune-inflammatory response. As long as the cysticercus remains viable, there is relative host immune tolerance. It is only when the parasite dies that massive antigen exposure occurs, with intensification of the immune response/inflammatory reaction and the appearance or worsening of symptoms. NCC can be asymptomatic or cause widely varied clinical manifestations, such as seizures, increased intracranial pressure, ischemic cerebrovascular disease, dementia, and signs of compression of the spinal roots/cord. The combination of two or more symptoms is common. Such clinical polymorphism is determined by 1) the number of lesions (single or multiple cysticerci); 2) the location of CNS lesions (subarachnoid, intracerebral, intraventricular, intramedullary); 3) the type of cysticercus (Cysticercus cellulosae, Cysticercus racemosus); 4) the stage of development and involution of the parasite (vesicular or viable, necrotic, fibrocalcified nodule); and 5) the intensity of the host immune-inflammatory response (no inflammatory reaction, leptomeningitis, encephalitis, granular ependymitis, arteritis).

Effects of prednisone on ventriculoperitoneal shunt function in hydrocephalus secondary to cysticercosis: a preliminary study

In a prospective open study, 15 patients with hydrocephalus secondary to cysticercosis who required insertion of a ventriculoperitoneal (VP) shunt were treated with 50 mg of prednisone given orally three times a week. Treatment began in the 1st postoperative week, with isoniazid and pyridoxine administered daily as antituberculous chemoprophylaxis. The drug regimen was continued with close follow up for 24 months. Clinical status, Karnofsky performance status (KPS) scores, and postoperative course in the prednisone-treated group were compared with 30 control patients with hydrocephalus due to cysticercosis. The control patients were matched by age and sex, underwent surgical shunting in the same period, and were followed routinely by the neurosurgery staff. Lumbar cerebrospinal fluid (CSF) was studied in 2, 16, and 32 weeks postoperatively in the prednisone group. At 24-month follow up two (13%) of 15 patients in the prednisone group and 19 (60%) of 30 patients in the control group required surgical shunt revisions for symptomatic shunt obstruction (p=0.002). Follow-up studies of CSF performed at 32 weeks in the prednisone group revealed improvement of abnormal values with statistically significant differences for glucose (p<0.02). Serial imaging studies in the prednisone group revealed persistence of cysticercal cysts with no change in size. Mean initial KPS scores were similar in both groups. At the end of the follow-up period, the mean KPS score was significantly higher in the prednisone group (p=0.003). Prednisone and chemoprophylactic drugs were well tolerated. These results suggest that in selected patients with hydrocephalus secondary to cysticercosis, intermittent long-term prednisone therapy after VP shunting may reduce shunt malfunction and improve the functional status of the patients.

Medical and surgical treatment in neurocysticercosis a magnetic resonance study of 161 cases

In a prospective non-controlled study we have treated 161 consecutive cases of Active Neurocysticercosis (NCC) diagnosed by Magnetic Resonance (MR). Active NCC was classified in: (1) brain parenchymal cysts (85 cases); (2) ventricular cysts (24 cases); (3) subarachnoid cysts (46 cases); and (4) cysticercus racemose (6 cases). All patients had MR follow up 1 month after treatment. Twenty five patients had MR with gadopentetate dimeglumine (Gd) contrast enhancement. Cine MR was performed in one patient. Medical treatment with albendazole (ABZ) or Praziquantel (PZQ) was applied in 136 cases. Drug efficacy, assessed by disappearance of the lesion on MR, was 92.5% with ABZ and 60% with PZQ. Thirty patients were treated by surgery. Five patients of group I were treated surgically due either to refractory seizures or persistent abnormalities on MR. Ventricular cysts were removed in 20 cases; 4 cases with cysticercus racemose and one with subarachnoid spinal cyst were also treated by surgery. Two patients with 4th ventricle cysts received ABZ and ventricular shunt only. Two cases with intraventricular cysts (lateral ventricles) and two with racemose cysts were successfully treated with ABZ. The Gd infusion showed enhancement in cysts with adjacent inflammatory reaction or edema and in cases with meningeal inflammation. Cine MR was useful in the differential diagnosis with congenital arachnoid cyst. We conclude that (1) MR is sensitive in the diagnosis of active NCC and may be useful in evaluating degenerative changes in the parasite; (2) ABZ is highly effective in the treatment of parenchymal and subarachnoidal NCC; (3) Parenchymal lesions which remain with abnormal appearance on MR (Degenerative cysticerci or gliosis) and refractory seizures should be treated by surgery; (4) Cysticercus racemose without intracranial hypertension may be treated with ABZ; (5) Ventricular cysts are treated by surgical removal, however, ABZ and ventricular peritoneal shunt may also be an alternative approach.

Human cysticercosis: parasitology, pathology, clinical manifestations and available treatment

Human cysticercosis is a global health problem and neurocysticercosis a serious clinical syndrome. The diagnosis of neurocysticercosis can now be made with a high degree of accuracy by scrutiny of clinical signs and symptoms in combination with X-ray, computed tomography or magnetic resonance imaging, serological tests and laboratory examinations. Differential clinical diagnosis with tumor, and vascular and inflammatory conditions, may however, prove difficult in nonendemic areas. The management of cysticercosis has been radically changed by the advent of effective chemotherapy. Both the heterocyclic pyrazinoisoquinoline compound, praziquantel and the benzimidazole carbamate, albendazole, have now been extensively tested and successfully used for treatments of neurocysticercosis, usually in combination with corticosteroids. The definition of appropriate criteria and guidelines for the use of chemotherapy, may however, require further research. Surgical interventions continue to play an important role in certain clinical presentations. Recent advances in immunological research hold realistic promise for the development of a vaccine against Taenia solium.

Reactivity in ELISA and dot blot of purified GP24, an immunodominant antigen of Taenia solium, for the diagnosis of human neurocysticercosis

In this paper we report the purification of GP24, one of the seven specific and highly antigenic Taenia solium glycoproteins previously identified by Western blot (WB) with serum, cerebrospinal fluid (CSF) and saliva samples from patients with neurocysticercosis (NC). GP24 was purified and evaluated in ELISA and dot blot for diagnosis. A lentil-lectin-bound glycoprotein fraction (LL-GP) from T. solium cysticerci was submitted to polyacrylamide gel electrophoresis, and the band that corresponded to GP24 was sliced, minced and electroeluted; an aliquot was used to immunize a rabbit, and the antiserum obtained was analysed by WB against LL-GP fraction; only GP24 was detected. ELISA and dot blot were performed with purified GP24 and serum and CSF samples from patients with NC that were previously positive for GP24 in WB and control samples; the latter were negative, while all NC samples were positive. To test for specificity, purified GP24 was incubated in dot blot against 44 sera from patients with other parasitic diseases; no positive reactions were found. Results indicate that GP24 was adequately purified and retained its reactivity; thus in combination with ELISA or dot blot may facilitate immunodiagnosis of NC.

Cerebral cysticercosis in Norway

Neurocysticercosis has been rare in Scandinavia. Due to immigration from and travels to endemic areas, we expect the number of such patients to increase. We here report the first four patients from Norway with diagnosed neurocysticercosis. Three are immigrants; one is of Norwegian heritage and was probably infested during short trips to other European countries.

Neurocysticercosis--a review of 231 cases

Two hundred thirty-one cases of neurocysticercosis are reviewed. Diagnosis was established by cerebral computed tomography during a seven-year period (1983-1989). One hundred and fourty-four (62%) presented with symptom-related disease (symptomatic neurocysticercosis and in 87 the diagnosis was incidental (asymptomatic neurocysticercosis). In symptomatic neurocysticercosis the parasitosis was considered inactive in 115 cases and active in 29. Seizures occurred in 135 patients (96% of the symptomatic neurocysticercosis). In the active form we also found: meningitis (n = 15), intracranial hypertension (n = 12), hydrocephalus (n = 10) and arteritis (n = 2). Treatment included praziquantel (n = 21), albendazole (n = 4), dexamethasone (n = 18) and surgery (n = 10).

Neurocysticercosis: a short review and presentation of a Scandinavian case

Cysticercosis is a disease entity caused by the larval form (Cysticercus cellulosae) of the pork tapeworm (Taenia solium). When man becomes the intermediate host, cysticercal cysts can develop in various organs. Neurocysticercosis, i.e. cysticercosis of the central nervous system, can lead to a broad range of neurological disturbances. The disease is usually confined to geographical regions where sanitation is poor but can occur among immigrants or travellers from such regions. Due to increased travel and immigration the disease may appear in non-endemic areas. We describe a recent case of neurocysticercosis in a 28-year-old Danish woman, who had been travelling in the Far East. She was successfully treated with praziquantel. A short review of the literature is given as the knowledge of the diagnosis and treatment of the disease has increased greatly in the last decade.

The relationship of antibody levels to the clinical spectrum of human neurocysticercosis

One hundred proven cases of cerebral cysticercosis were studied with an enzyme linked immunoassay (ELISA) employing cyst fluid as antigen, with a view to detecting specific antibodies in serum and cerebrospinal fluid (CSF). Antibody levels were correlated with the clinical presentation of the patients, the type and number of cysts detected on their brain scans, the anatomical position of these cysts and the presence of lymphocytes in the CSF. Patients could be divided into two distinct categories, one with low levels of antibody in the serum and absent antibody in the CSF, and the other with high levels in both the serum and the CSF. This differentiation matched the clinical presentation of a benign and a malignant group. Antibody levels could not be related to the type of cysts as observed on the brain scan, but depended on the anatomical position of the cyst, being lower if the cysts were confined to the cerebral cortex. A correlation of antibody levels with the number of cysts was only found in the benign group.

Immunoglobulin E and G4 antibodies in cysticercosis

The importance of immunoglobulin G (IgG) subclass responses in different infections has been elucidated for a number of organisms, but few parasitic organisms have been examined in this regard. In the current study, quantitative radioimmunoassays were used to examine the IgE and IgG4 subclass responses to larval Taenia solium. Patients were divided into clinically infected (CI) and probably uninfected (PU) groups. Unexposed normal subjects were used as controls. The CI group had elevated geometric mean levels of total IgE in serum (28.6 IU/ml) and specific IgG4 antibodies (438.8 arbitrary units [AU]/ml) compared with controls (8.3 IU/ml and 50.1 AU/ml, respectively). The CI group also had significantly elevated levels in cerebrospinal fluid of total IgG4 (18.6 micrograms/ml) and specific IgG4 antibodies (86.0 AU/ml) compared with the PU group (2.5 micrograms/ml and 1.6 AU/ml, respectively). There was no specific IgE antibody response detected in either the CI or PU patient group. The marked IgG4 response of CI patients to T. solium merits further investigation.

Taenia crassiceps metacestode vesicular fluid antigens shared with the Taenia solium larval stage and reactive with serum antibodies from patients with neurocysticercosis

After removal of host (mouse) serum proteins (albumin, transferrin, IgG and another five unidentified proteins) by immunoaffinity chromatography, the vesicular fluid of T. crassiceps metacestodes (TcVF) was immunoelectrophoretically examined for antigens recognized by rabbit antiserum to aqueous crude extract of T. solium cysticerci. Based on a precipitate pattern developed in electroimmunodiffusion, nine cross-reactive antigens could be demonstrated. In the ELISA, TcVF was shown to be a potent antigen for the demonstration of IgG antibodies in the sera of Mexican patients (n = 14) with confirmed neurocysticercosis (mean E490 values +/- SD: 0.39 +/- 0.38) although it was less sensitive when compared to T. solium VF (0.95 +/- 0.54). Sensitivity was much higher using cross-reactive TcVF antigens selected by immunoaffinity chromatography with rabbit IgG antibodies to larval T. solium crude extract (0.87 +/- 0.57). SDS-PAGE fluorograph of cross-reactive, radioiodinated TcVF protein antigens and selected by antibodies of individual neurocysticercosis sera (n = 13), exhibited six to nine bands depending on the serum tested. Altogether ten 125I-labelled proteins (Mr range from about 20,000 to 200,000) were recognized by neurocysticerosis antibodies. Four proteins (Mr about 22,000, 25,000, 32,000 and 45,000) were detected by all sera.

Humoral immune response in patients with cerebral parenchymal cysticercosis treated with praziquantel

The humoral immune response to treatment with praziquantel (PZQ) was studied in eight patients with parenchymal cerebral cysticercosis (CC). In the serum and in the cerebrospinal fluid (CSF) before, during and after the administration of the drug, the following were quantitated (a) levels of specific anticysticercous antibodies measured in optical densities by the ELISA method; (b) levels of IgG, IgM, IgA and IgE; (c) levels of complement fraction C3, C4; (d) presence of immune complexes; (e) total number of white blood cells in the CSF. It was found that after treatment with PZQ, the level of specific anticysticercous antibodies and the level of IgG rose significantly in the CSF but not in the blood. The levels of the fractions of the complement and the immunoglobulins IgM, IgA and IgE did not change significantly either in the serum or in the CSF. The blood-brain barrier was found ruptured in three patients before therapy and in five patients after the therapy as measured by the albumin index. Nevertheless, the IgG index showed that there was local production of IgG in five patients before treatment and in seven after the end of it. The relative specific antibody index was greater than 1.0 in five patients before therapy and in seven after therapy. This data strongly supports the idea that the specific antibodies are produced intrathecally and are not derived from the serum pool through a ruptured blood-brain barrier. It was concluded that patients with parenchymal CC have an elevation of specific anticysticercous probably due to a combination of a ruptured blood-brain barrier and intrathecal synthesis. The relatively small rupture of the blood-brain barrier and the high IgG and relative specific antibody index suggest that intrathecal synthesis is the most important mechanism. The humoral immune response may be of importance not only in the elimination of the parasite but also in the genesis of the illness.

Sudden death from cerebral cysticercosis

A case of sudden death from cysticercosis cerebri is described. A 38-year-old Ecuadorian woman suffered from headache for a few weeks which was interpreted as migraine. Later she developed extremely severe headache with seizures and died. A forensic autopsy showed normal organs. Neuropathologic examination revealed cysticercosis racemosus with reactive chronic ependymitis and meningitis and secondary hydrocephalus.

Improvements in the serodiagnosis of helminthic zoonoses

Remarkable progress has been achieved in developing improved serodiagnostic assays for a group of diseases for which other diagnostic methods are often lacking. Toxocariasis, trichinellosis, dirofilariasis, Taenia solium cysticercosis and the cystic and alveolar forms of hydatid disease are occult infections in humans and sometimes in lower animal hosts. Although Strongyloides stercoralis achieves patency in humans, parasitologic diagnosis is often very difficult. Efforts to develop reliable immunodiagnostic methods have spanned several decades but progress had been slow until recently. The complexity and nonspecificity of helminth antigens were major problems which prevented the full realization of the benefits of the highly sensitive assay systems now available. Modern immunologic methods including hybridoma technology, immunoaffinity chromatography and immunoblotting, however, have yielded improved reagents and the means to characterize their nature and function. The outcome of this research has been more sensitive and specific serologic tests based on measurement of both circulating antigens and antibodies as well as improved understanding of the nature of host-parasite interactions. Although much remains to be done, many improved immunodiagnostic procedures are already being applied in clinical diagnosis, epidemiologic studies and control programs directed against the helminthic zoonoses.