New perspectives in diagnosis of hemostasis disorders

The classical coagulation analyses are performed either by using manual methods or by means of various instruments with a different degree of automation. The introduction of chromogenic peptide substrates which can be split by thrombin has led to the development of photometric assays for PT and aPTT determination independent from the fibrinogen concentration and from its conversion to fibrin. After that, turbidimetric methods for the determination of fibrinogen, thrombin time and batroxobin time have been set up allowing the use of photometry for the determination of the most important hemostaseological parameters. For such purposes a new analytical system (ChromoTimeSystem, Behringwerke AG, Marburg/FRG) based on a special instrument and reagents for chromogenic and turbidimetric methods for coagulation and fibrinolysis has been developed. The ChromoTimeSystem allows to perform by photometry all important tests for coagulation and fibrinolysis. The analytical characteristics of this new system are presented.     

脑猪囊尾蚴病的临床病理诊断

目的：探讨脑猪囊尾蚴病的临床病理特点及诊断方法。方法：复习12例脑猪囊尾蚴病的病理切片、病史及临床资料。结果：男女发病性别比3：1，平均年龄22岁。临床以癫痫发作为主要症状9例，颅内高压2例，痴呆1例。5例见到猪囊尾蚴，7例虫体崩解的陈旧性病变均找到形态不一的石灰小体。结论：脑猪囊尾蚴病以青年男性多见，癫痫发作为主要症状。病理诊断除找到囊尾蚴外，组织中散在的石灰小体是陈旧性病变的重要诊断依据。     

Fine needle aspiration in the diagnosis of subcutaneous cysticercosis

Human cysticercosis commonly manifests as subcutaneous and intramuscular nodules. The current study highlights the role of fine needle aspiration cytology (FNAC) in the diagnosis of subcutaneous cysticercosis. One hundred and twenty two patients with subcutaneous swellings, diagnosed as cysticercus or suspicious of parasitic inflammation on FNAC, were included in the present study. The relevant clinical data, cytomorphological findings, and histopathological findings, wherever available were evaluated. In 57 cases, a definite evidence of cysticercus was obtained in the form of fragments of parasite bladder wall, hooklets, or intact larva. Out of these, biopsy correlation was available in 10 cases, eight of which failed to reveal any parasite. In 65 cases, larval fragments could not be identified on aspirates, and the diagnosis of parasitic inflammation was suggested on the basis of other cytomorphological findings, which are discussed. In 22 of these cases, a biopsy correlation was available, which revealed definite parasitic elements in six cases and the remaining 16 cases were reported as suggestive of parasitic cysts. Thus, to conclude, FNAC is a reliable and cost effective procedure for the diagnosis of subcutaneous parasitic nodules. It obviates the need for a subsequent histopathological examination, as the parasite may not be demonstrated even on biopsy specimens.     

Enzyme-linked immunosorbent assay for the diagnosis of cerebral cysticercosis

Central nervous system cysticercosis is common in countries where Taenia solium occurs in pigs and the level of hygiene and sanitation is low. The clinical presentation may include epileptic seizures, focal neurological deficits, hydrocephalus, or aseptic meningitis. The disease is frequently seen in California residents of Hispanic origin. It sometimes occurs in whites from homes that employ Hispanic cooks. Diagnosis is often difficult. Computerized tomography scan and brain biopsy are the most reliable diagnostic procedures, but each has its limitations. We have found that a radioimmunoassay improves our diagnostic capability, and more recently we have adapted this to an enzyme-linked immunosorbent assay that is equally sensitive and specific and, in addition, obviates the need for radioactive materials. Details of the enzyme-linked immunosorbent assay procedure and its application to the diagnosis of central nervous system cysticercosis form the basis of this report.     

Specificity of isoelectric focusing-purified antigens in the diagnosis of human cysticercosis

Specific antigens were isolated from the cystic fluid of larval Taenia solium by preparative isoelectric focusing (PIEF). A total of 20 fractions were produced by a rotating ampholine column with pI 3–10 ampholytes. The specificity of each fraction (F) was tested by double-antibody enzyme-linked immunosorbent assay (ELISA) using antisera from patients suffering from cysticercosis or one of six other parasitic diseases. F8–F15 cross-reacted strongly with sera from patients with hydatidosis. F9 and F10 also cross-reacted with the antisera against ascariasis and F15, with antisera against angiostrongylosis. However, F16 and F17 were highly specific as they yielded no cross-reaction with any of the heterologous antisera. PIEF is a good method for the production of specific antigens from larval T. solium because it is easy to perform and relatively inexpensive to run. Received: 29 November 1997 / Accepted: 10 February 1998     

Immunologic diagnosis of the cerebrospinal fluid and serum in developing brain cysticercosis

ELISA detection of specific antibodies in the serum (IgG) and cerebrospinal fluid (IgG, IgM and IgA) was evaluated in 28 patients. Diagnosis of cerebral cysticercosis and evaluation of disease activity was based on CT scan findings. Specific IgG antibodies were found in the serum in 83.3% of patients with active disease and 10% of those with inactive disease. Cerebrospinal fluid tests evidenced specific antibodies in all patients with active disease and none of the patients with inactive disease. The specific CSF antibodies were IgG (94.4%), IgM (66.6%) or IgA (66.6%). Antibody titers were significantly higher in patients with an intraventricular vesicle or cyst.     

Evaluation of an antigen-ELISA in the diagnosis of bovine cysticercosis in Kenyan cattle

A monoclonal antibody-based antigen-ELISA (Ag-ELISA) was studied in Kenyan cattle with the objective of evaluating its reliability in diagnosing bovine cysticercosis. A total of 55 cattle divided into artificially (n = 30) and naturally (n = 25) infested animals, were utilized. Total dissection was used as a gold standard of validity at autopsy. In natural infestations, the assay identified 16 cases as true seropositives, 2 cases as false seropositives, 3 cases as true seronegatives and 4 cases as false seronegatives. While in artificial infestations, the assay identified 9 cases as true seropositives, 14 cases as true seronegatives and 7 cases as false seronegatives. There weren’t any false seropositive cases identified with artificial infestations. The assay showed good precision level and kappa level in quantifying the relative quality of the amount of agreement in natural (n = 25; k = 0.482; p > 0.05) and artificial (n = 24; k = 0.374; p > 0.05) infestations. The study showed that, besides other advantages, the Ag-ELISA with its sensitivity of 60.00–80.00%, specificity of 60.00–100%, predictive value of 88.89–100%, apparent prevalence of 37.50–72.00% and accuracy of 75.00–76.00% may be recommended for use in combination with other control measures, viz chemotherapy, post-mortem diagnosis and or vaccination. The Kenya Agricultural Research Institute (KARI) at Helminthology Division, National Veterinary Research Centre (NVRC), Muguga, Kenya, the European Union (EU) and Germany Academic Exchange Service (DAAD) jointly funded this project. We are very grateful to them for their financial support.     

Fine-needle aspiration cytology in the diagnosis of cysticercosis presenting as palpable nodules

The cytologic findings in the fine-needle aspirate of 30 cases of cysticercosis presenting as palpable nodules are described. Essential for a diagnosis are identification of parasitic fragments. These include bluish fibrillary structures sometimes with honeycombing, tegument of parasite thrown into rounded wavy folds, and scolex with hooklets and hyaline membrane surrounding it. The inflammatory reaction consisted of eosinophils, neutrophils, lymphocytes, histiocytes, epithelioid cells, and giant cells in varying proportions.     

Evaluation of enzyme-linked immunoassay for serological diagnosis of cysticercosis.

We evaluated a commercially available enzyme-linked immunoassay (ELISA) from LMD Laboratories, Inc., Carlsbad, Calif., for the detection of antibodies in serum to the cysticercus of Taenia solium. The ELISA was performed on 308 serum samples; 198 from a pool of healthy individuals, 42 from patients who had antibodies against a variety of parasites other than T. solium, and 68 from patients suspected of having cysticercosis. All of these 68 specimens were tested both by the ELISA and by an immunoblot method (enzyme-linked immunoelectrotransfer blot assay [EITB]) developed at the Parasitic Serology Laboratory of the Centers for Disease Control and Prevention. Twenty-seven of the 68 serum samples from patients suspected of having cysticercosis were positive by both EITB and ELISA, while 31 were negative by both assays. ELISA results for three and two samples were considered false positive and false negative, respectively, when compared with the results of EITB. Results for an additional five samples were considered equivocal but were technically positive because their optical density readings were slightly above the cutoff value. Three of the 198 serum samples from the bank of serum samples from healthy individuals were also false positive by ELISA (the EITB result for the samples was negative). Six other serum samples from healthy individuals which had equivocal results and the five serum samples from patients with equivocal results were EITB negative. Serum samples containing antibodies against Echinococcus spp. frequently cross-reacted with the cysticercus ELISA antigen (13 of 16 specimens), but serum samples with antibodies against other parasites did not (2 of 26 specimens); all of these serum samples were EITB negative. The commercially available ELISA that we describe is a simple and rapid test. Considering all 308 specimens, the ELISA had a specificity of 93% (when samples with equivocal results were considered negative) or 89% (when samples with equivocal results were considered positive); the sensitivity was 93%.     

DNA differential diagnosis of taeniasis and cysticercosis by multiplex PCR

Multiplex PCR was established for differential diagnosis of taeniasis and cysticercosis, including their causative agents. For identification of the parasites, multiplex PCR with cytochrome c oxidase subunit 1 gene yielded evident differential products unique for Taenia saginata and Taenia asiatica and for American/African and Asian genotypes of Taenia solium with molecular sizes of 827, 269, 720, and 984 bp, respectively. In the PCR-based detection of tapeworm carriers using fecal samples, the diagnostic markers were detected from 7 of 14 and 4 of 9 T. solium carriers from Guatemala and Indonesia, respectively. Test sensitivity may have been reduced by the length of time (up to 12 years) that samples were stored and/or small sample volumes (ca. 30 to 50 mg). However, the diagnostic markers were detected by nested PCR in five worm carriers from Guatemalan cases that were found to be negative by multiplex PCR. It was noteworthy that a 720 bp-diagnostic marker was detected from a T. solium carrier who was egg-free, implying that it is possible to detect worm carriers and treat before mature gravid proglottids are discharged. In contrast to T. solium carriers, 827-bp markers were detected by multiplex PCR in all T. saginata carriers. The application of the multiplex PCR would be useful not only for surveillance of taeniasis and cysticercosis control but also for the molecular epidemiological survey of these cestode infections.     

Present status of laboratory diagnosis of human taeniosis/cysticercosis in Europe

Human cysticercosis (CC) is a parasitic zoonosis caused by the larval stage (cyst) of the Taenia solium. Cysts can establish in the human central nervous system (neurocysticercosis, NCC) and other organs and tissues; they also develop in pigs, the natural intermediate host. Human taeniosis may be caused by T. solium, Taenia saginata and Taenia asiatica tapeworms; these infections are usually asymptomatic, but show a significant relevance as they perpetuate the parasites’ life cycle, and, in the case of T. solium, they are the origin of (N)CC. In European Union (EU) member states and associated countries, the occurrence of autochthonous T. solium cases is debated, and imported cases have significantly increased lately; the status of T. asiatica has been never reported, whereas T. saginata is prevalent and causes an economic impact due to condemned carcasses. Based on their effects on the EU society, the specific diagnosis of these pathologies is relevant for their prevention and control. The aims of this study were to know the diagnostic tests used in European laboratories for human taeniosis/cysticercosis by means of a questionnaire, to determine potential gaps in their detection, and to obtain preliminary data on the number of diagnosed taeniosis/CC cases.     

Clinical, epidemiological and laboratory criteria for the diagnosis of human cysticercosis in Brazilian patients

Cysticercosis (CC) is a polymorphous disease, which makes its diagnosis difficult. This study had the objective of evaluating the clinical, epidemiological and laboratory criteria in human CC. An epidemiological questionnaire was applied, and indirect fluorescence antibody test (IFAT) and ELISA-IgG were utilized together with computerized tomography and/or magnetic resonance imaging on 90 patients with clinical signs suggestive of neurocysticercosis (NCC). Most patients had previously lived under deficient basic sanitary conditions. The imaging techniques showed that 92.2% of the cysticerci were in the cerebral parenchyma, 5.5% had a ventricular location, 1.1% were periventricular and 1% was ocular. The cysticerci were observed to be predominantly in the inactive phase. Seropositivity to the IFAT and/or ELISA was shown by 32.2% (29/90). Of the 29 seropositive patients, 72.4% presented cysticerci in the inactive form, and of the 61 seronegative patients, 78.7% also presented cysticerci in the inactive form. There was no correlation between active CC and seropositivity, since 72.4% of the seropositive patients presented calcified cysticerci. The results demonstrated that imaging techniques contributed significantly to elucidate the laboratorial diagnosis and to evaluate the stage of cysticercus development.