Cerebral sparganosis presenting with atypical postcontrast magnetic resonance imaging findings: a case report and literature review.

BACKGROUND: Sparganosis, a rare and severe parasitic infection caused by the larvae of Spirometra species or simply sparganum, generally involves subcutaneous tissue or muscle. But occasionally, sparganum can also invade the human brain, resulting in cerebral sparganosis. CASE PRESENTATION: A 33-year-old woman presented with a 10-day history of headache. Postcontrast magnetic resonance imaging (MRI) revealed an irregular lesion with enhancement and the tunnel-shaped focus extending to the contralateral hemiphere. Cerebrospinal fluid (CSF) analysis disclosed pleocytosis (166 cells/µL) and an elevated protein concentration (0.742 g/L). Enzyme-linked immunosorbent assay (ELISA) revealed positive sparganum-specific antibody in both blood and CSF. Finally, the diagnosis of cerebral sparganosis was comfirmed. She received praziquantel treatment and got a favorable outcome during six-month follow-up. CONCLUSIONS: Irregular enhancement and the tunnel sign that extends to the contralateral hemisphere on postconstrast MRI are unusual presentations of cerebral sparganosis. ELISA for sparganum-specific antibody can help confirm the diagnosis. Although surgery is the preferred treatment for cerebral sparganosis, praziquantel might also achieve satisfying outcomes.

Molecular cloning and characterization of a Spirometra erinacei casein kinase I.

The Spirometra erinacei casein kinase I (SeCKI) gene was cloned and expressed in Escherichia coli, and its characteristics were investigated in this study. The recombinant SeCP protein (rSeCKI) was purified. The vaccination of mice with rSeCKI induced the Th1/Th2-mixed type of immune response with Th2 predominant (high levels of IgG1). Western blotting analysis showed that rSeCP was recognized by the sera of plerocercoid-infected mice, and anti-rSeCP serum recognized the native SeCP protein of plerocercoid crude antigens. Transcription and expression of SeCP was observed at the plerocercoid and adult stages of S. erinacei. Immunolocalization identified SeCKI in the tegument and parenchymal tissues of plerocercoids and in the teguments of adults. SeCKI appeared to be essential indispensable for the S. erinacei development and survival in host, but its biological functions need to be further investigated.

Serodiagnosis of sparganosis by ELISA using recombinant cysteine protease of Spirometra erinaceieuropaei spargana.

The Spirometra erinaceieuropaei cysteine protease (SeCP) gene encoding a 36 kDa protein was expressed in Escherichia coli, and the potential of recombinant SeCP protein (rSeCP) as an antigen for the serodiagnosis of sparganosis was investigated by ELISA and compared with those of ELISA with sparganum excretory-secretory (ES) antigens. The sensitivity of rSeCP-ELISA and ES-ELISA was 96.67 % (29/30) and 100 % (30/30) respectively, for the detection of anti-sparganum IgG antibodies in sera of the experimentally infected mice (P > 0.05), and the specificities of both ELISA were 100 % (77/77). In heavily, moderately, and lightly infected mice (five, three, and one larvae per mouse), anti-sparganum antibodies were firstly detected by rSeCP-ELISA at 10-12 days post-infection (dpi), respectively, and then continued to increase with a detection rate of 100 % at 14-22 dpi. In three groups of infected mice, the anti-sparganum antibody levels at different times after infection were statistically different (P < 0.05). The results showed that the rSeCP might be a potential candidate antigen for early and specific serodiagnosis of sparganosis. But, it needs to be further evaluated with sera of the patients with sparganosis and other helminthiasis.

Analysis of structures, functions, and epitopes of cysteine protease from Spirometra erinaceieuropaei Spargana.

Spirometra erinaceieuropaei cysteine protease (SeCP) in sparganum ES proteins recognized by early infection sera was identified by MALDI-TOF/TOF-MS. The aim of this study was to predict the structures and functions of SeCP protein by using the full length cDNA sequence of SeCP gene with online sites and software programs. The SeCP gene sequence was of 1 053 bp length with a 1011 bp biggest ORF encoding 336-amino acid protein with a complete cathepsin propeptide inhibitor domain and a peptidase C1A conserved domain. The predicted molecular weight and isoelectric point of SeCP were 37.87 kDa and 6.47, respectively. The SeCP has a signal peptide site and no transmembrane domain, located outside the membrane. The secondary structure of SeCP contained 8 α -helixes, 7 ß -strands, and 20 coils. The SeCP had 15 potential antigenic epitopes and 19 HLA-I restricted epitopes. Based on the phylogenetic analysis of SeCP, S. erinaceieuropaei has the closest evolutionary status with S. mansonoides. SeCP was a kind of proteolytic enzyme with a variety of biological functions and its antigenic epitopes could provide important insights on the diagnostic antigens and target molecular of antisparganum drugs.

Suppression of IP-10/CXCL10 gene expression in LPS- and/or IFN-γ-stimulated macrophages by parasite-secreted products.

T helper (Th)2 polarized immune responses are characteristically dominant in helminth infections. The gene expression of interferon (IFN)-γ-inducible protein 10 (IP-10/CXCL10), which promotes Th1 responses, in mouse macrophages stimulated with lipopolysaccharide (LPS) and/or IFN-γ was suppressed by excretory/secretory (ES) products of Spirometra erinaceieuropaei plerocercoids. ES products suppressed LPS- and/or IFN-γ-induced transcriptional activities of a luciferase reporter gene under the control of a 243-bp fragment of the IP-10 gene promoter/enhancer, which contains an IFN-stimulated response element (ISRE) and two κB elements. Consistent with this result, ES products inhibited ISRE-dependent heterologous promoter activities and LPS- or IFN-γ-induced ISRE-binding activity. ES products also suppressed LPS-induced IFN-ß gene expression. Furthermore, ES products suppressed nuclear factor (NF)-κB RelA (p65)-dependent transcriptional activity, whereas ES products had no effect on the κB-binding activity. These results suggest that ES products suppress the IP-10 gene expression by inhibiting the ISRE- and RelA-dependent transcriptional activities in mouse macrophages.

Two-dimensional immunoblot analysis of antigenic proteins of Spirometra plerocercoid recognized by human patient sera.

Sparganosis is caused by invasion of Spirometra plerocercoid into various tissues/organs. Subcutaneous sparganosis can be diagnosed and treated by worm removal, while visceral/cerebral sparganosis is not easy to diagnose. The diagnosis depends largely on the detection of specific antibodies circulating in the patients' sera. Previous studies demonstrated that 31 and 36kDa proteins of the sparganum invoked specific and sensitive antibody responses, but also showed cross reactions with cysticercosis sera. We enriched protein fractions containing 31-36kDa through gel filtration and examined immune recognition pattern against the patient sera by 2-dimensional electrophoresis (2-DE) followed by immunoblotting. Serum samples from sparganosis patients recognized 8-10 protein spots of 31 and 36kDa with different isoelectric point (pI) values with variable combinations, in which four spots of 31kDa with pIs 3.4, 3.9, 4.0 and 4.1, and one 36kDa spot (pI 3.5) appeared to be specifically reactive. One 31kDa protein spot with pI 3.3 and two spots of 36kDa with pIs 3.3 and 3.5 reacted crossly with neurocysticercosis sera. Neither sera from patients with other parasitic infections nor those from healthy controls showed positive reaction. Two-DE/immunoblot analysis might be highly available in differential serodiagnosis of human sparganosis.

Production of polyclonal antibodies against the tegument of sparganum (plerocercoid of Spirometra mansoni) and its immunolocalization.

In a previous study, the author developed a method for separation of the tegument of spargana (plerocercoids of Spirometra mansoni) from the parenchyme using urea. The present study, as a next step, was performed to evaluate which molecules are present in the outer tegument. Two major proteins, 180 and 200 kDa, are present in the tegument and we could make polyclonal antibodies against these molecules. Their immunolocalization was processed and the outermost layer of the spargana showed strong positive staining. Conclusively, we could confirm that the 180 and 200 kDa molecules might be tightly bound membrane proteins in the tegument of spargana.

Enzymatic N-glycan analysis of 31 kDa molecule in plerocercoid of Spirometra mansoni (sparganum) and its antigenicity after chemical oxidation.

A highly specific antigenic protein of 31 kDa from plerocercoid of Spirometra mansoni (sparganum) was obtained by gelatin affinity and Mono Q anion-exchange column chromatography. The purified 31 kDa protein was subjected to N-glycan enzymatic digestion for structural analysis. The relative electrophoretic mobility was analyzed by SDS-PAGE, before and after digestion. On SDS-PAGE after enzymatic digestion, the 31 kDa protein showed a molecular shift of approximately 2 kDa, which indicated the possession of complex N-linked oligosaccharides (N-glycosidase F sensitive) but not of high-mannose oligosaccharides (endo-beta-N-acetylglucosaminidase H, non-sensitive). Chemically periodated 31 kDa protein showed statistically non-significant changes with human sparganosis sera by enzyme linked immunosorbent assay (ELISA). Therefore, the dominant epitopes of the 31 kDa molecule in human sparganosis were found to be mainly polypeptide, while N-glycans of the antigenic molecule in sparganum was minimal in anti-carbohydrate antibody production.

Modification of carbohydrate compositions of 31/36 kDa proteins of plerocercoids (sparganum) of Spirometra mansoni grown in different intermediate hosts.

We purified specific 31/36 kDa antigenic molecules from sparganum in different intermediate hosts (snakes and mice) and analyzed their monosaccharide compositions. Compositional analysis showed that glucose and mannose concentrations were 2-3 fold higher in the 31/36 kDa molecule purified from snakes than those from mice. This result implies that antigenic glycoproteins of sparganum from snakes might be modified in mammalian sparganosis with respect to their carbohydrate composition.

A seroepidemiologic survey for human sparganosis in Gangweon-do.

Gangweon-do is known to be highly endemic area of sparganosis more than other provinces in Korea. A seroepidmiologic examination for the detection of anti-Spirometra erinacei plerocercoid IgG in serum was carried out in normal inhabitants in Hongcheon-gun, Gangweon-do. Sere were tested by enzyme-linked immunosrobent assay (ELISA) for the anti-sparganum antibodies. Positive rate for anti-sparganum antibody in 719 adults was 3.3%. Data of the questionnaire for 24 ELISA positive inhabitants revealed that 20 had a history of eating raw meat of snakes, 24 had a history of eating frogs, and 24 had a history of drinking stream water. Two positive cases had a past history of sparganosis. Two positive cases showed current symptoms of sparganosis. The data revealed that ELISA would be useful to find infected cases among normal inhabitants at sparganosis-endemic areas.

A rare case of eosinophilic pleuritis due to sparganosis.

A rare form of sparganosis with eosinophilic pleural effusion is reported. A 62-year-old man was admitted to our hospital with left pleural effusion, and diagnosed immunologically as having sparganosis. Eosinophilia was seen in both peripheral blood and pleural effusion. The level of interleukin (IL)-5 was elevated in the pleural effusion, but not in peripheral blood. The patient was treated successfully with three consecutive doses of praziquantel (75 mg/ kg/day). After the treatment, the antibody titer in serum decreased and the eosinophil number in the peripheral blood returned to the normal level. Thus, sparganosis should be included in the differential diagnosis for eosinophilic pleuritis. The immunoserological screening test using multiple-dot ELISA is helpful to identify the causative pathogen.

[Detection of anti-Spirometra erinaceieuropaei antibody using ELISA].

OBJECTIVE: To study specific diagnosis of Spirometra erinaceieuropaei. METHODS: An enzyme-linked immunosorbent assay (ELISA) was studied using highly pure gene engineering antigen expressed by the recombination of the cloned cysteine proteinase gene of Spirametra erinaceieuropaei with expression vector pMAL-c2. Six sera from patient infected with Spirometra erinaceieuropaei were detected using this method. RESULTS AND CONCLUSION: The results showed that the gene engineering antigen reacted strongly with the sera from Spirometra erinaceieuropaei-infected patients, but did not with the sera from Cysticercus cellulosae-infected patients.

[Molecular cloning of a cDNA encoding an antigenic polypeptide containing repeat units of Spirometra erinaceieuropaei plerocercoid].

AIM: To study the gene structure encoding some antigenic polypeptides of plerocercoid of Spirometra erinaceieuropaei (SEP). METHODS: A cDNA library constructed from SEP was immunoscreened using mouse anti-SEP polyclonal antibody. The gene structure was analyzed by computer after the insert of positive clone was subcloned and the nucleotide sequences of the insert were determined. The length of mRNA hybridized with cDNA was detected by Northern blotting. RESULTS: A cDNA clone of 1,084 bp encoding an antigenic polypeptide was isolated. The clone contained one open reading frame composed of 828 bp encoding 276 amino acids. The open reading frame contained tandem repeating unit of 123 bp which appeared 5 times in this clone. The 41 amino acids deduced from 123 bp repeating unit consisted of 53.7% of hydrophobic amino acid residues. In Northern blot assay of poly (A)+RNA, a strong band of about 1.1 kb and a weak band of about 1.7 kb were found in the plerocercoids but no band was found in the adult worms. CONCLUSION: The repeating element derived from the plerocercoids may be associated with the migration of the plerocercoids in the host tissue. The polypeptides with repeating element may act as evasive antigens of the parasite to escape from the destruction of host immune reactions.

Excretory/secretory products from plerocercoids of Spirometra erinacei reduce iNOS and chemokine mRNA levels in peritoneal macrophages stimulated with cytokines and/or LPS.

During infection with plerocercoids of Spirometra erinacei, organisms in the peritoneal cavity of infected animals have many bound inflammatory leukocytes yet survive apparently unharmed. Coculture of IFN gamma and LPS stimulated mouse peritoneal macrophages with live plerocercoids suppressed the mRNA expression of the inducible isoform of nitric oxide synthase (iNOS) and JE, the murine homologue of monocyte chemotactic protein-1 (MCP-1). Excretory/secretory (ES) products from plerocercoids also suppressed the induced iNOS and JE mRNA and reduced nitrite production of macrophages in a dose dependent manner. The suppression of inducible mRNA levels in macrophages cultured for 24 h with ES products varied with the nature of the stimuli; IFN gamma/ LPS-induced iNOS mRNA levels were effected less than were iNOS mRNA levels induced by IFN gamma/IL-2 or IFN gamma/ TNF alpha. Similar findings were obtained when nitrite production was measured. Thus modulation of LPS and cytokine inducible mRNA levels appear to be the primary target of ES products. We speculate that a major physiological role for this inhibitory activity in ES products might be the down regulation of pro-inflammatory gene expression.

The metabolism of arachidonic acid to prostaglandin E2 in plerocercoids of Spirometra erinacei.

With a simplified method of extracting and purifying prostaglandins, trace prostaglandins (nanogram order) were detected by gas chromatography-mass spectrometry. Arachidonic acid was metabolized to prostaglandin E2 (PGE2) by plerocercoids of Spirometra erinacei, the PGE2 was detected in the medium after incubation with arachidonic acid, and the role of albumin in the absorption of free arachidonic acid by plerocercoids and in the release of its metabolite was investigated. Plerocercoids absorbed arachidonic acid-binding albumin and released PGE2 efficiently. PGE2 is known to suppress the functions of mononuclear cells of the host. The selective release of PGE2 may be related to the escape mechanism of plerocercoids of S. erinacei from the host immune system to become established larva migrans, i.e., sparganosis.

Purification of antigenic protein of sparganum by immunoaffinity chromatography using a monoclonal antibody.

The quality improvement of antigen (crude saline extract) of Spirometra mansoni pleroceroid (sparganum) was investigated by protein purification. The crude extract was fractionated by gel filtration through Sephacryl S-300 Superfine. Its third fraction was purified by affinity chromatography using a monoclonal antibody as ligand. When observed by SDS-PAGE, the purified protein was composed of 2 bands of 36 kDa and 29 kDa which were found already as the most sensitive components in the crude extract by immunoblots with patients sera. The quality of the purified antigen was evaluated in comparison with the crude extract by enzyme-linked immunosorbent assay (ELISA) for the specific (IgG) antibody in sera of human sparganosis, other parasitic and neurologic diseases, and normal control. When the purified antigen was used, the sensitivity was not altered but remained high (96.4%) while the specificity was increased from 86.8% to 96.9%.

Leukocyte accumulation in sparganosis: demonstration of eosinophil and neutrophil chemotactic factors from the plerocercoid of Spirometra erinacei in vivo and in vitro.

In order to determine whether the plerocercoid of Spirometra erinacei itself has eosinophil and neutrophil chemotactic factors, in vivo and in vitro examinations were carried out. We could observe large numbers of eosinophils and neutrophils which accumulated at the injection site of normal guinea pig skin following intradermal injection of soluble extract of plerocercoids of S. erinacei. At 1 hour after the injection, neutrophils appeared at the site, and the cell number reached its peak at 4 hours. Eosinophils appeared rather later than neutrophils (at 2-4 hours), and the number of cells reached its peak at 8 hours after the injection. Eosinophil and neutrophil chemotactic activities were also confirmed in an in vitro system by using a blind-well chemotaxis chamber with a Millipore filter in dose dependent fashion. An eosinophil chemotactic factor (ECF) with molecular weight of approximately 15,000, and two different neutrophil chemotactic factors, one of about same molecular weight as the ECF and the other of low molecular weight, were demonstrated by gel filtration on Sephadex G-200. Furthermore, it was confirmed that those factors were released from parasite by the detection of intensive eosinophil and neutrophil chemotactic activities in the culture supernatants containing plerocercoids.