Luís dos Ramos Machado

Taenia solium DNA is present in the cerebrospinal fluid of neurocysticercosis patients and can be used for diagnosis

Neurocysticercosis is the most frequent parasitic infection of the CNS and the main cause of acquired epilepsy worldwide. Seizures are the most common symptoms of the disease, together with headache, involuntary movements, psychosis and a global mental deterioration. Absolute diagnostic criteria include the identification of cysticerci, with scolex, in the brain by MRI imaging. We demonstrate here, for the first time, that T. solium DNA is present in the cerebrospinal fluid of patients. The PCR amplification of the parasite DNA in the CSF enabled the correct identification of 29/30 cases (96.7 %). The PCR diagnosis of parasite DNA in the CSF may be a strong support for the diagnosis of neurocysticercosis.

The Role of Conventional MR Imaging Sequences in the Evaluation of Neurocysticercosis: Impact on Characterization of the Scolex and Lesion Burden

BACKGROUND AND PURPOSE: There are few studies comparing the capacity of lesion detection of conventional MR imaging in neurocysticercosis (NCC). This study was designed to clarify its role in the evaluation of this disease, focusing on the total number of lesions identified and the characterization of the scolex. MATERIALS AND METHODS: MR images from 115 patients were prospectively collected during a 3-year interval, including axial spin-echo (SE) T1-weighted; axial fast SE T2-weighted; axial fluid-attenuated inversion recovery (FLAIR); and gadolinium-enhanced axial, coronal, and sagittal SE T1-weighted sequences. They were compared regarding the potential for detection of NCC lesions and specifically of the scolex. RESULTS: Comparing all sequences, we found that FLAIR images were more sensitive to the detection of the scolex (P < .003), whereas the last gadolinium-enhanced T1-weighted series (coronal or sagittal) identified the highest number of lesions (P < .001). CONCLUSION: When dealing with NCC, optimal MR imaging protocols should include FLAIR images to obtain maximal rates of scolex detection. Special attention should be paid to the last gadolinium-enhanced sequence, which maximizes the quantification of lesion load.

Neurocysticercosis: detection of IgG, IgA and IgE antibodies in cerebrospinal fluid, serum and saliva samples by ELISA with Taenia solium and Taenia crassiceps antigens

We assayed samples of cerebrospinal fluid (CSF), serum and saliva from patients with neurocysticercoses, control group and individuals with other parasitoses, by ELISA with Taenia crassiceps vesicular fluid antigen (Tcra) and Taenia solium total antigen (Tso) for the detection of antibodies. The sensitivity for IgG-Tcra was 100% for CSF and serum, and 32.0% for saliva; and for IgG-Tso 100% for CSF, 80.0% for serum and 24.% for saliva. Specificity was 100% for CSF and 80.0% for serum with both antigens, and 100% for saliva with Tcra and 87.5% with Tso. The sensitivity and specificity for IgA-Tcra was, respectively, 40.0% and 100% for CSF, 36.0% and 97.1% for serum, and 4.0% and 90.0% for saliva. IgE detection showed 24.0% sensitivity and 97.1% specificity for serum, with no detection in CSF samples. The search for antibodies revealed the presence of IgG > IgA > IgE in CSF, serum and saliva samples, with IgG being present in all phases of the disease, while IgA/IgE were more frequent in the inactive form.

Cysticercosis of the central nervous system and cerebrospinal fluid immunodiagnosis of 1573 patients in 63 years (1929-1992)

Attention given to prophylaxis of neurocysticercosis (NC) is far beyond minimal needs among several regions of the in-development world, and for this reason incidence of the disease persists high among them. This investigation was carried out to show the extent of the problem by analysing the incidence of NC in a region of Brazil (São Paulo). CSF immunodiagnosis of NC by detecting antibodies to Cysticercus cellulosae in a neurodiagnostics laboratory is evaluated for this purpose. Cases studied in a 63-year period (1929-1992) are reviewed. Total cases in this period is 139,000, and for 1,573 (1.13%) diagnosis is NC. Special characteristics were not detected for colour and sex prevalence. Age bracket prevalence is from 21 to 40 years old (55.3%) high rates occurring for women between 21 to 30 years old, and for men between 31 to 40. Cases distribution in five consecutive decades (1942-1991) shows no decreasing tendency: average incidence is 1% for the 50 years, and it is over this average for the last three decades. Data confirm that incidence continues expressively high throughout the 50 years covered by this study.

Computed tomography in neurocysticercosis a 10-year long evolution analysis of 100 patients with an appraisal of a new classification

Three hundred and fifty seven computed tomography (CT) from 100 different patients with neurocysticercosis (NC) were studied between 1979 and 1988. All patients were treated with praziquantel (PZQ). A new classification attempting to recognize the CT evolution profile in NC as well as assigning a possible link between CT findings and biological conditions of cysts is evaluated. It was possible to conclude that: intact cysts remain unchanged in consecutive CTs by 11 months and exhibit signs of degeneration in about 18 months after PZQ drug therapy; degenerating cysts can be detected by 10.5 months, disappear in 11 months and become nodular calcifications in about 25 months. Therefore, a time period of at least 36 months can be estimated for the complete evolution profile of cysts in the brain parenchyma.

Use of Taenia crassiceps Cysticercus Antigen Preparations for Detection of Antibodies in Cerebrospinal Fluid Samples from Patients with Neurocysticercosis (Taenia solium)

ABSTRACT Antigen extracts obtained from the vesicular fluid of Taenia crassiceps cysticerci and from fractions purified by affinity chromatography with the lectin concanavalin A and the glycoprotein antigen separated by electrophoresis were used for the detection of Taenia solium anticysticercus antibodies. The sensitivity and specificity obtained for all antigens were 100% in enzyme-linked immunosorbent assay with good reproducibility. Using immunoblotting of the three antigens, low-molecular-mass peptides (18 and 14 kDa) were characterized only in cerebrospinal fluid samples from patients with neurocysticercosis. The results confirm that antigen fractions purified from T. crassiceps cisticerci are important sources of specific peptides and proved to be efficient in detecting anti-T. solium antibodies.

Cysticercosis Immunodiagnosis Using 18- and 14-Kilodalton Proteins from Taenia crassiceps Cysticercus Antigens Obtained by Immunoaffinity Chromatography

ABSTRACT Monoclonal antibodies (MAb) against Taenia crassiceps and Taenia solium cysticerci were produced and showed cross-reactivity with a 14-kDa protein from T. solium and with 18- and 14-kDa proteins from T. crassiceps. These MAbs and antibodies from cerebrospinal fluid (CSF) as well as serum samples from patients with neurocysticercosis (NC) reacted with 18- and 14-kDa T. crassiceps proteins purified by immunoaffinity chromatography using a Sepharose column coupled with MAbs (anti-excretory/secretory or anti-vesicular fluid antigens). Immunoaffinity-purified 18- and 14-kDa proteins were used in the design of a diagnostic enzyme-linked immunosorbent assay (ELISA) to detect antibodies in 23 CSF and 20 serum samples from patients with NC, showing 100% sensitivity. The test specificity was determined using 42 noninflammatory CSF samples and 70 inflammatory CSF samples from patients with other neurological disorders (OND), showing 100% and 99.1% (confidence interval, 97.3% to 100%) specificity, respectively. A false-positive CSF sample result in the OND group was from a human immunodeficiency virus-positive patient with meningoencephalitis. By using serum samples from 194 healthy individuals, the specificity was 100%. Analysis of an additional 16 serum samples from individuals with other parasitic diseases (13 with intestinal parasitosis and 3 with schistosomiasis) showed negative results. Three (10%) serum samples from patients with hydatidosis were positive in our ELISA and in ELISA with T. solium cysticerci antigens. Two of them were also positive by immunoblotting. The use of 18- and 14-kDa T. crassiceps immunoaffinity-purified proteins for detection of anti-cysticercus antibodies in CSF and/or serum samples using an ELISA system showed a good performance and high specificity for serum samples, dispensing with the use of confirmatory tests, such as immunoblotting, for checking specificity.

Cysticercus Antigens in Cerebrospinal Fluid Samples from Patients with Neurocysticercosis

ABSTRACT Antigens were detected in cerebrospinal fluid (CSF) samples from patients with neurocysticercosis (NC) by enzyme-linked immunosorbent assay (ELISA) using polyclonal sera of rabbit anti-Taenia solium cysticerci (anti-Tso) and anti- Taenia crassiceps cysticerci vesicular fluid (anti-Tcra or anti-Tcra <30 kDa). A group of NC patients (n = 174) were studied (NC), including 40 patients in different phases of the disease. ELISAs carried out with the anti-Tso, anti-Tcra, and anti-Tcra <30 kDa showed sensitivities of 81.2, 90, and 95.8% and specificities of 82, 98, and 100%, respectively. The 14- and 18-kDa low-molecular-weight peptides were only detected in CSF samples from patients with NC by immunoblotting with anti-Tso and anti-Tcra sera. Because of the importance of the diagnosis and prognosis of cysticercosis, the detection of antigens may contribute as an additional marker to the study and clarification of the parasite-host relationship.

Anormalidades do líquido cefalorraqueano em 170 casos de AIDS

Cerebrospinal fluid (CSF) was analysed in 170 AIDS patients. All of them showed HIV positive serological tests. All of them showed neurologic syndromes related to AIDS. The time period of the investigation was July 1984-April 1989. In 8 cases (4.7%) CSF composition was normal. Lymphoma cells were observed in three cases. Aseptic meningities occurred in 34 cases (20.1%). Aetiological diagnosis of associated infection was established in 88 cases: cryptococcosis in 28 (35.9%); toxoplasmosis in 20 (25.6%); syphilis in 10; candidiasis in 3; Chagas disease in 2; tuberculosis in 1; nocardiosis in 1; schistosomiasis in 1. Antibodies for other virus were detected in 7. Bacteria were isolated in 5 cases. Anti-HIV antibodies were tested in CSF samples of 55 cases: they were found in 48 (87.3%). Two or more associated infections were observed in 15 cases. Changes of CSF composition in AIDS are discussed taking into account changes reported.

HTLV-1 antibodies in serum and cerebrospinal fluid in tropical spastic paraparesis in Brazil

HTLV-1 antibodies were investigated in serum and in CSF of 150 patients with neurologic disorders mainly myelopathies. The patients were considered into three groups according to the possible relationship of their disease to the presence of HTLV-1 antibodies: no relationship risk (control group), occasional risk group, and possible risk group. In this latter are 56 patients with crural spastic paraparesis or paraplegia of unknown etiology (SP). HTLV-1 antibodies were tested by the passive particle-agglutination method for anti-ATLA antibody detection. The search was negative in all patients of the control group, and positive (serum and/or CSF) in 16.5% of the patients from the second group and in 55.4% of the SP patients group. Clinical patterns in SP cases with HTLV-1 antibodies were those of tropical spastic paraparesis (TSP). CSF patterns considered (cytology, protein content and gamma-globulins rate) were different between TSP group with HTLV-1 antibodies in CSF and SP group with no HTLV-1 antibodies detection either in serum or in CSF. The difference was significant. Results of this investigation confirm the high incidence of TSP in Brazil, and bring additional indication for searching HTLV-1 antibodies in the CSF.