Neuroimmunological findings of Angiostrongylus cantonensis meningitis in ecuadorian patients / Hallazgos neuroinmunologicos en meningitis por Angiostrongylus cantonesis en pacientes ecuatorianos

Meningitis caused by Angiostrongylus cantonensis has recently been reported in patients resulting from the first outbreaks in subtropical regions of Ecuador. METHOD: Eight young adult patients from the two outbreaks were studied. IgA, IgM, IgG and albumin in cerebrospinal fluid and serum were quantified and plotted in cerebrospinal fluid/serum quotient diagrams (Reibergrams). The anamnesis on the patients included asking about any consumption of raw snails, symptoms and harm caused. RESULTS: Mean eosinophilia of 7.5 percent and 26 percent in serum and cerebrospinal fluid respectively was observed, as well as a moderate increase in total proteins. The most frequent pattern of intrathecal synthesis was observed in three classes of immunoglobulins. Intrathecal synthesis of IgM was observed in all cases two weeks after the first symptoms appeared. CONCLUSION: The intrathecal synthesis patterns of eosinophilic meningitis due to Angiostrongylus cantonensis, facilitated by cerebrospinal fluid analysis, were similar to those of previous cases from abroad.

La meningitis provocada por Angiostrongylus cantonensis ha sido reportada recientemente en pacientes procedentes de los primeros brotes reportados en regiones subtropicales de Ecuador. MÉTODO: Ocho adultos jóvenes procedentes de dos brotes fueron estudiados. Se cuantificó IgA, IgM, IgG y albúmina en suero y líquido cefalorraquídeo y fueron colocados en los gráficos de las razones líquido cefalorraquídeo/suero (reibergramas). La anamnesia incluía ingestión de caracoles crudos, los síntomas y los daños provocados. RESULTADOS: Una eosinofílica promedio de 7,5 y 26 por ciento en suero y líquido cefalorraquídeo fue observada al igual que un moderado incremento en las proteínas totales. El patrón de síntesis intratecal predominante fue de tres clases de inmunoglobulinas. La síntesis intratecal de IgM se observó en todos los casos a las dos semanas después del inicio de los síntomas. CONCLUSIÓN: El patrón de síntesis intratecal de la meningitis eosinofílica por Angiostrongylus cantonensis facilitado por el análisis del líquido cefalorraquídeo fue similar a los casos previos reportados fuera del país.

Detection of the acute phase of abdominal angiostrongyliasis with a parasite-specific IgG enzyme linked immunosorbent assay

Angiostrongylus costaricensis may cause intestinal lesions of varied severity when it accidentally infects man in Central and South America. First-stage larvae have never been detected in stools. Therefore, a parasite-specific IgG ELISA was evaluated for the determination of the acute phase of infection. The specificity and the sensitivity of the immunoassay was shown to be 76.2 percent and 91.1 percent, respectively. Eight serum samples taken from patients with histopathological diagnosis, at different time points (3 to 15 months) after surgical treatment, showed a sharp and early decline in antibody reactivity. The titration of anti-A. costaricensis antibodies has proved to be a useful method for the diagnosis of acute abdominal angiostrongyliasis

Angiostrongyliasis: analysis of antigens of Angiostrongylus costaricensis adult worms versus IgG from infected patients with Angiostrongylus cantonensis.

The possibility of cross-reactivity was previously investigated by indirect ELISA with sera from Angiostrongylus cantonensis infections, normal controls and A. costaricensis antigen. 5 microg/ml of crude antigen from both sexes of each species reacted with diluted serum samples (1:800) of each of 20 cases of angiostrongyliasis and normal controls, and further with anti-human IgG conjugate at 1:1,000. The mean absorbance values were evaluated as follows; normal controls showed a value of 0.033 using A. costaricensis antigen lower than (0.085) A. costaricensis antigen. Both mean values of angiostrongyliasis cases were rather close (0.491) using A. costaricensis antigen and the other antigen (0.518). The present study continued with a crude antigen of 13 A. costaricensis females and males. Serum samples were analyzed; 27 sera of angiostrongyliasis, 30 negative controls and 193 cases of other parasitic infections (91 cases of nematodiasis; 45 cases of cestodiasis; 47 cases of trematodiasis and 10 cases of HIV) and 7 cases of other brain infections. This antigen was evaluated for ELISA with a concentration of 5 microg/ml, serum dilution 1:400 and anti-human IgG conjugate at 1:2,000. The test gave sensitivity and specificity at cut-off value 0.261; 92.59% and 73% respectively. The antigen was cross-reactive with 30 cases from 9 out of 10 different kinds of nematodiasis (gnathostomiasis, strongyloidiasis, ascariasis, hookworm infections, trichinosis, toxocariasis, trichuriasis, onchocercosis and Wuchereria bancrofti infections. Five cases from 3 of 6 kinds of cestodiasis (neurocysticercosis, echinococcosis and Hymenolepis nana infections) and 18 cases of 4 out of 5 kinds of trematodiasis (Paragonimus heterotremus infections, opisthorchiasis, schistosomiasis and fascioliasis). One case of other brain infections was observed. The crude antigen of A. costaricensis showed a high percentage sensitivity with serum antibodies of angiostrongyliasis cases. Low specificity of the test was observed by reactions of those serum antibodies with various kinds of antigenic molecules. This study provides baseline data for further immunodiagnosis of human angiostrongyliasis.

The evaluation of the 29 and 31 kDa antigens in female Angiostrongylus cantonensis for serodiagnosis of human angiostrongyliasis.

The objective of this study was to evaluate the crude somatic extract of female Angiostrongylus cantonensis by ELISA and to evaluate the 29 kDa and the 31 kDa components of female worm by EITB for serodiagnosis of human angiostrongyliasis. Using ELISA, cross reaction occurred among all sera tested except capillariasis. The sensitivity, specificity, positive and negative predictive values of ELISA were found to be 100%, 66.8%, 27.1% and 100% respectively. Using EITB, The 29 kDa component cross-reacted with most of the heterologous sera while the 31 kDa component was recognized by 69.2% (18/26) sera from angiostrongyliasis patients, cross-reacted only with trichinellosis, trichuriasis and opisthorchiasis sera. This component may possibly used as reliable agents for angiostrongyliasis out of other tissue infected helminthiasis. The sensitivity, specificity, positive and negative predictive values of EITB for the 31.0 kDa component were 69.2%, 82.4%, 46.2% and 92.5% respectively.

Detection of circulating antigens of Parastrongylus cantonensis in human sera by sandwich ELISA with specific monoclonal antibody.

A specific monoclonal antibody (AW-3C2) as revealed by ELISA was produced against the adult worm antigens of Parastrongylus cantonensis and used in a sandwich ELISA for the detection of circulating antigens in the sera of parastrongyliasis patients and those with other parasitic diseases. A total of 60 sera was used in this study. Of these, 10 each were from patients with parastrongyliasis, cysticercosis, filariasis, gnathostomiasis, malaria and toxocariasis. The control group consisted of 53 serum samples from normal healthy Thais and Malaysians. The mean +/- optical density (OD) values for the normal Thai and Malaysian groups were 0.126 +/- 0.028 and 0.124 +/- 0.029, respectively. The mean OD values of the parastrongyliasis patient group differed significantly from that of the normal groups as well as those of other parasitic infections. Using a cut-off point of OD +/- 3SD of the control groups as indicating a positive reading, the specificity of the assay with this monoclonal antibody was 100% while the sensitivity was 50%.

Modulatory effects of metanil yellow on immunity in rodents.

Pathomorphological and immunological studies were carried out on rodents following oral administration of 0, 0.1, 0.25 and 0.5% (w/w) metanil yellow, mixed in diet, for 30 days. No significant change in hematologic parameters and histologic architecture of liver, kidney, mesenteric lymph node, thymus and urinary bladder was observed except for mild desquamation of intestinal villi and moderate changes in Peyer's patches of small intestine with higher doses. Among immunological parameters, significant enhancement in the primary humoral immune response (anti-SRBC IgM plaque forming cells of spleen) was observed with the lowest dose of metanil yellow while higher doses produced opposing effects. An elevated cutaneous delayed type hypersensitivity (DTH) reaction to SRBC was seen in 0.1% metanil yellow treated animals but higher doses did not influence the reaction. The treatment also caused changes in functional capabilities of macrophages. Although these immune alterations could hardly influence the local immunity of gut, as measured by the capacity of animals to cause rejection of Nippostrongylus brasiliensis parasite, the potential to modulate the immunity in general by metanil yellow however assumes considerable biological significance.