Experimental neurocysticercosis: absence of IL-4 induces lower encephalitis / Neurocisticercose experimental: ausência de IL-4 induz menos encefalite

ABSTRACT Neurocysticercosis (NCC) is the most severe clinical manifestation of cysticercosis. One of the factors responsible for its symptomatology is the host inflammatory response. Therefore the influence of interleukin 4 (IL-4) on the induction of encephalitis in experimental NCC was evaluated. Methods BALB/c (WT) and BALB/c (IL-4-KO) mice were inoculated intracranially with Taenia crassiceps cysticerci and euthanized at 7, 30, 60 and 90 days later, the encephala removed and histopathologically analyzed. Results The absence of IL-4 induced greater parasitism. In the initial phase of the infection, IL-4-KO showed a lower intensity in the inflammatory infiltration of polimorphonuclear cells in the host-parasite interface and intra-parenquimatous edema. The IL-4-KO animals, in the late phase of the infection, showed lower intensity of ventriculomegaly, encephalitis, and meningitis, and greater survival of the parasites in comparison with the WT animals. Conclusion The absence of IL-4 induced lower inflammatory infiltration, ventriculomegaly and perivasculitis in experimental NCC.

RESUMO A Neurocisticercose (NCC) é a manifestação clínica mais severa da cisticercose, e um dos fatores responsáveis pela sintomatologia é a resposta inflamatória do hospedeiro. Desta forma avaliou-se a influência da interleucina 4 (IL-4) na indução de encefalite na NCC experimental. Métodos Camundongos das linhagens BALB/c (WT) e BALB/c (IL-4-KO) foram inoculados intracranialmente com cisticercos de Taenia crassiceps e eutanasiados aos 7, 30, 60 e 90 dias após a infecção, os encéfalos foram removidos e analisados histopatologicamente. Resultados A ausência da IL-4 induziu um maior parasitismo nos animais. Na fase inicial da infecção os animais IL-4-KO apresentaram menor intensidade tanto de infiltrado inflamatório de polimorfonucleares na interface parasito-hospedeiro quanto de edema intraparenquimatoso. Os animais IL-4-KO, na fase tardia, apresentaram menor intensidade de ventriculomegalia, encefalite, meningite e maior sobrevivência dos cisticercos em relação aos animais WT. Conclusão A ausência da IL-4 induz menos infiltrado inflamatório, ventriculomegalia e perivasculite na NCC experimental.

A serological study of cysticercosis in patients with HIV / Estudo sorológico da cisticercose em pacientes com HIV

Neurocysticercosis (NCC) has attained the importance of one of the most common cause of focal brain lesions in patients infected with HIV (human immunodeficiency virus). Adequate data regarding the rate of this co-infection is lacking. Therefore, the present study was carried out to determine the prevalence of cysticercosis among HIV patients residing in Puducherry or its neighboring districts of Tamil Nadu State, India. A total of one hundred blood samples were collected from HIV seropositive cases visiting JIPMER hospital, Puducherry, between June 2007 and May 2008. Enzyme immunotransfer blot (EITB) and enzyme linked immunosorbent assay (ELISA) were used to demonstrate anti- T. solium larval stage antibodies and Co-agglutination (Co-A) test was used to detect T. solium larval stage antigens in sera. Two HIV seropositive cases were found positive for anti-T. solium larval stage antibody by EITB and four were positive by ELISA. Only one sample was positive by both EITB and ELISA. No serum sample was found positive for T. solium larval stage antigen by Co-A test. The overall seropositivity detected by all the methods was 5 percent in this study group. The accurate clinical diagnosis of NCC in HIV is difficult due to deranged immunological parameters in the HIV infected patients. The results of this study provides important data on the prevalence of cysticercosis in HIV positive patients in Puducherry and neighboring areas which was previously unknown. This study will also increase awareness among physicians and public health agencies about T. solium cysticercosis in the selected group.

Neurocisticercose (NCC) tem alcançado a importância de uma das mais comuns causas de lesões focais no cérebro em pacientes infectados pelo HIV (vírus da imunodeficiência adquirida). Dados adequados relativos à frequencia desta co-infecção estão faltando. Portanto, o presente estudo foi realizado para determinar a prevalência da cisticercose entre pacientes com HIV residindo em Puducherry ou distritos vizinhos do Estado de Tamil Nadu, India. Um total de cem amostras foram coletadas de casos soropositivos do Hospital JIPMER, Puducherry, entre junho de 2007 e maio de 2008. "Enzyme immunotransfer blot" (EITB) e ELISA foram utilizados para demonstrar anticorpos contra a fase larval do T. solium. Testes de co-aglutinação (Co-a) foram usados para demonstrar antígenos da fase larval do T. solium no soro. Dois casos HIV soropositivos foram positivos para anticorpos contra a fase larval do T. solium por EITB e quatro foram positivos por ELISA. Somente uma amostra foi positiva por ambos EITB e ELISA. Nenhuma amostra de soro foi positiva para antígeno da fase larval do T. solium pelo teste Co-a. A soropositividade total detectada por todos os métodos foi 5 por cento neste grupo de estudo. O diagnóstico clínico exato de NCC em HIV é difícil devido aos desordenados parâmetros imunológicos nos pacientes infectados pelo HIV. Os resultados deste estudo fornecem dados importantes sobre a prevalência da cisticercose em pacientes HIV positivos em Puducherry e áreas vizinhas que eram previamente desconhecidos. Este estudo também aumentará a atenção dos médicos e agências de saúde pública sobre a cisticercose por T. solium em grupo selecionado.

A clinico-serological study of neurocysticercosis in patients with ring enhancing lesions in CT scan of brain.

AIMS OF THE STUDY: To study the clinical profile of neurocysticercosis and the utility of serological test using enzyme linked immunosorbent assay (ELISA) in patients with ring enhancing lesions in CT scan of brain. METHODS: A total of 51 patients presenting between April 2003 to March 2004 to the Assam Medical College and Hospital, Dibrugarh, with ring enhancing lesions in CT scan of brain suggestive of neurocysticercosis were included in the study. Serum samples for ELISA test were taken from all patients and controlled sera were taken from 20 patients admitted in the ward, who did not have clinical evidence of cysticercosis and whose CT scan of brain were either normal or revealed lesion other than cerebral cysticercosis. RESULTS: The maximum incidence of neurocysticercosis was found in the age group between 21 and 30 years (43.41%). Seizures were the commonest clinical presentation (100%). Eleven patients (21.56%) had ring enhancing lesions with central scolex. Fourty patients (78.44%) showed only ring enhancing lesions. ELISA test for definitive neurocysticercosis showed a sensitivity of 82.60% and specificity of 100%, while patients with CT scan features of neurocysticercosis had a sensitivity of 78.43% with ELISA. CONCLUSION: ELISA for cysticercosis showed a sensitivity of 82.60% and specificity of 100%. The study also shows that therapeutic effectiveness with albendazole is quite satisfactory. As the study population is small in number which was conducted in a span of one year, an evaluation with a larger number of patients will definitely throw more light on the subject.

Serum and cerebrospinal fluid S100B concentrations in patients with neurocysticercosis

The clinical manifestations of neurocysticercosis (NC) are varied and depend on the number and location of cysts, as well as on the host immune response. Symptoms usually occur in NC when cysticerci enter a degenerative course associated with an inflammatory response. The expression of brain damage markers may be expected to increase during this phase. S100B is a calcium-binding protein produced and released predominantly by astrocytes that has been used as a marker of reactive gliosis and astrocytic death in many pathological conditions. The aim of the present study was to investigate the levels of S100B in patients in different phases of NC evolution. Cerebrospinal fluid and serum S100B concentrations were measured in 25 patients with NC: 14 patients with degenerative cysts (D), 8 patients with viable cysts (V) and 3 patients with inactive cysts. All NC patients, except 1, had five or less cysts. In most of them, symptoms had been present for at least 1 month before sample collection. Samples from 8 normal controls (C) were also assayed. The albumin quotient was used to estimate the blood-brain barrier permeability. There were no significant differences in serum (P = 0.5) or cerebrospinal fluid (P = 0.91) S100B levels among the V, D, and C groups. These findings suggest that parenchymal changes associated with a relatively small number of degenerating cysts probably have a negligible impact on glial tissue.

Diagnosis of neurocysticercosis by enzyme-linked immunosorbent assay.

Neurocysticercosis, a disease caused by larvae of T solium produces variable and non-specific symptoms. Computerised tomography, magnetic resonance imaging, immunological tests in the serum and cerebrospinal fluid are available options to diagnose the condition. Two hundred serum samples collected and stored frozen at -20 degrees C and were tested for cysticercosis by commercial Melotest cysticercosis kit. Diagnosis was confirmed by other investigations. After the confirmative diagnosis results of ELISA for cysticercosis were compared and the values of sensitivity, specificity, prevalence and precision were obtained along with positive and negative predictive values. Overall prevalence was found to be 10% in this study. Only 26.5% serologically positive cases had neurocysticercosis positively. The positive predictive value of the serological test was only 26.4% suggesting that the diagnosis of neurocysticercosis by ELISA is not reliable in an endemic area.

A serological study of human cysticercosis in Pondicherry, South India.

The present study was carried out to determine the extent of the problem of cysticercosis in Pondicherry by assessing the antibody response to porcine cysticercus antigen by the indirect haemagglutination (IHA) in people residing in and around Pondicherry and in patients clinically suspected to have cysticercosis. Serum samples were collected from 1442 persons apparently normal in respect to cysticercosis, 91 cases of clinically suspected cases of cysticercosis, and 100 normal healthy students and blood donors. These sera were tested for cysticercus antibodies by IHA test using whole porcine cysticercus antigen sensitised RBCs. An antibody titre of 1:64 and above by the IHA was considered to be diagnostic of cysticercosis. At this diagnostic titre, 88 (6.10 %) of 1442 apparently normal population sera were seropositive. Of these 88 seropositive subjects, 16 (18.18 %), 33 (37.5 %) and 32 (36.36 %) were in the age groups of 1-13 yrs, 14-40 years and above 40 years respectively. 52 (59.1%) were males and 36 (40.9 %) were females. Twenty (21.97%) out of 91 clinically suspected cases were found to be seropositive out of which 14 (70 %) were males and 6 (30 %) females. 4 cases were in the age group of 6-13 years, 14 cases in 14-40 years and 2 cases were in the age group of 40 years and more. Cysticercus antibodies were not detected in any of the sera from healthy peoples including students. A positive antibody response in 6.1 % of population residing in and around Pondicherry and in 21.97 % of patients clinically suspected cases of cysticercosis show that cysticercosis may be more common in Pondicherry than believed.

Differential serodiagnosis of cystic and alveolar echinococcosis using native and recombinant antigens in Japan.

Our group at Asahikawa Medical College has established differential serodiagnosis for zoonotic larval cestodiases such as alveolar echinococcosis (AE), cystic echinococcosis (CE) and neurocysticercosis (NCC) using purified specific antigens. In this brief review, we introduce (a) four imported CE cases in Japan, easily identified serologically, (b) most recent advances in serology for differentiation of AE and monitoring of prognosis of AE in Japan. It includes application of affinity purified Em18 and prototype of a recombinant Em18 antigen. Serology using affinity purified Em18 antigens is showing much higher sensitivity for detection of AE cases which are usually undetectable by the ongoing serology for AE authorized in Hokkaido, Japan. As serology for AE, CE or NCC is still not popular in the majority of Asian countries, we expect that this review paper stimulates researchers who are interested in serology or serodiagnosis for these larval cestodiases including AE, CE and NCC.

Recent advances in serodiagnosis for cysticercosis.

Neurocysticercosis (NCC) caused by infection with the larval stage of Taenia solium is an important cause of neurological disease worldwide. Up to the present, many studies on characterizing species-specific antigens of T. solium have been done and several high quality antigens for serodiagnosis are available. Hence the research on serodiagnosis has been shifted to the next phase, stable production of diagnostic antigens using molecular techniques. In order to establish an enzyme-linked immunosorbent assay (ELISA) using recombinant proteins, we carried out molecular cloning and identified four diagnostic antigen candidates (Ag1, Ag1V1, Ag2, and Ag2V1). Recombinant proteins, except Ag2V1, were successfully expressed using an Escherichia coli expression system. Immunoblot analysis using NCC patient sera detected recombinant proteins. But as reactivity to rAg1 was too weak, Ag1 was not suitable for the immunodiagnosis antigen. Therefore Ag1V1 and Ag2 were chosen for ELISA antigens and Ag1V1/Ag2 chimeric protein was expressed. Of 49 serum samples from NCC patients confirmed to be seropositive by immunoblot analysis, 44 (89.7%) were positive by ELISA. Serum samples from patients with other parasitic infections did not recognized Ag1V1/Ag2 chimeric protein. Ag1V1/Ag2 chimeric protein obtained in this study is of value for differential immunodiagnosis.

Cysticercus immunoblot assay in patients with single, small enhancing lesions and multilesional neurocysticercosis.

A single, small (< 20 mm), ring or disc shaped contrast enhancing lesion located at the cortical-subcortical junction with minimal or no surrounding edema on computed tomography is the commonest mode of presentation of neurocysticercosis in the Indian subcontinent. Serum samples of 37 patients with these single, small enhancing lesions (SSEL's) and five patients with typical multilesional parenchymal neurocysticercosis were tested by the electro-immunoblot transfer (EITB) assay and the enzyme linked immunosorbent assay (ELISA). EITB was positive in 18 patients (48.64%) and ELISA was positive in 21 patients (56.76%) with SSEL's. On the other hand EITB was positive in all five patients (100%) and ELISA was positive in four patients (80%) with multilesional neurocysticercosis. The low sensitivity of the EITB in the SSEL's is probably linked to an insufficient immune stimulation provided by a single cysticercus cyst.

Use of delipidized antigens of Taenia solium metacestodes in IgG-ELISA for detection of neurocysticercosis.

The development of IgG-ELISA for detecting neurocysticercosis is aimed at the routine laboratory, and requires a particular antigen preparation, an acceptable number of serum samples to be tested (both homologous and heterologous) and patients with a diversity of helminthic infections to rule out cross-reactions. This study characterizes IgG-antibodies from cases of neurocysticercosis by assaying the sera against ether-delipidized antigens (5 microg/ml) prepared from metacestodes of Taenia solium. The test had a sensitivity of 90% and a specificity of 83%. IgG-antibodies from heterologous serum samples elicited a number of false positives (25/147) from six different helminthic infections, ie paragonimiasis, echinococcosis, opisthorchiasis, ascariasis, taeniasis and fascioliasis. In additional tests to detect antibody levels to these stage-related antigens, one of three serum samples from T. solium-infected cases gave negative at OD value of 0.187 while the others yielded 0.472 and 0.576. Conversely, assays of all serum samples from neurocysticercosis cases reacted against antigens from Echinococcus granulosus cystic fluid, Paragonimus heterotremus and Opisthorchis viverrini adult worms. In comparison, the antigens from these three species yielded higher mean OD values when assayed against the corresponding infected serum samples. Furthermore, neurocysticercosis cases yielded OD values that are separate and distinct from those of paragonimiasis cases.