Evaluation of cysticercus-specific IgG (total and subclasses) and IgE antibody responses in cerebrospinal fluid samples from patients with neurocysticercosis showing intrathecal production of specific IgG antibodies / Avaliação das respostas de anticorpos anti-cisticercos IgG (total e subclasses) e IgE em amostras de líquido cefalorraquidiano de pacientes com neurocisticercose apresentando produção intratecal de anticorpos específicos IgG

In the present study, an enzyme-linked immunosorbent assay (ELISA) standardized with vesicular fluid of Taenia solium cysticerci was used to screen for IgG (total and subclasses) and IgE antibodies in cerebrospinal fluid (CSF) samples from patients with neurocysticercosis showing intrathecal production of specific IgG antibodies and patients with other neurological disorders. The following results were obtained: IgG-ELISA: 100% sensitivity (median of the ELISA absorbances (MEA)=1.17) and 100% specificity; IgG1-ELISA: 72.7% sensitivity (MEA=0.49) and 100% specificity; IgG2-ELISA: 81.8% sensitivity (MEA=0.46) and 100% specificity; IgG3-ELISA: 63.6% sensitivity (MEA=0.12) and 100% specificity; IgG4-ELISA: 90.9% sensitivity (MEA=0.85) and 100% specificity; IgE-ELISA 93.8% sensitivity (MEA=0.60) and 100% specificity. There were no significant differences between the sensitivities and specificities in the detection of IgG-ELISA and IgE-ELISA, although in CSF samples from patients with neurocysticercosis the MEA of the IgG-ELISA was significantly higher than that of the IgE-ELISA. The sensitivity and MEA values of the IgG4-ELISA were higher than the corresponding values for the other IgG subclasses. Future studies should address the contribution of IgG4 and IgE antibodies to the physiopathology of neurocysticercosis.

No presente estudo, uma reação imunoenzimática (ELISA) padronizada com o fluido vesicular de cisticercos de Taenia solium foi utilizada para avaliar as respostas de anticorpos anti-cisticercos IgG (total e subclasses) e IgE em amostras de líquido cefalorraquidiano (LCR) de pacientes com neurocisticercose apresentando produção intratecal de anticorpos específicos IgG e pacientes com outras desordens neurológicas. Os seguintes resultados foram obtidos: ELISA-IgG: 100% de sensibilidade (mediana das absorbâncias das reações ELISA (MAE)=1,17) e especificidade 100%; ELISA-IgG1: sensibilidade 72,7% (MAE=0,49) e especificidade 100%; ELISA-IgG2: sensibilidade 81,8% (MAE=0,46) e especificidade 100%; ELISA-IgG3: sensibilidade 63,6% (MAE=0,12) e especificidade 100%; ELISA-IgG4: sensibilidade 90,9% (MAE=0,85) e especificidade 100%; ELISA-IgE: sensibilidade 93,8% (MAE=0,60) e especificidade 100%. Não foram encontradas diferenças significativas entre as sensibilidades e especificidades das reações ELISA-IgG e ELISA-IgE, embora a MAE da reação ELISA-IgG em amostras de LCR de pacientes com neurocisticercose tenha sido significativamente maior que a obtida com ELISA-IgE. Os valores de sensibilidade e MAE da reação ELISA-IgG4 foram maiores que os valores correspondentes para as outras subclasses da IgG. Estudos futuros deverão abordar a contribuição dos anticorpos IgG4 e IgE na fisiopatologia da neurocisticercose.

Total IgE detection in paired cerebrospinal fluid and serum samples from patients with neurocysticercosis

Neurocysticercosis (NC), the presence of Taenia solium metacestodes in tissues, is the most frequent and severe parasitic infection of the central nervous system. We investigated the presence of total IgE by an automated chemiluminescence assay in 53 paired cerebrospinal fluid (CSF) and serum samples from patients with NC (P) and in 40 CSF samples from individuals with other neurological disorders as the control group (C). Total IgE concentration ranged from 1.2 to 6.6 IU/ml (mean = 1.4 IU/ml, standard deviation-sd = 1.1 IU/ml) in 28.3 per cent of CSF samples from the P group, a value significantly higher than for the C group (< or = 1.0 IU/ml). The serum samples from the P group showed concentrations ranging from 1.0 to 2330.0 IU/ml (mean = 224.1 IU/ml, sd = 452.1 IU/ml), which were higher than the normal value cited by the manufacturer (<100.0 IU/ml) in 32.1 per cent of the samples. A significant difference was observed in CSF samples from the P and C groups (p = 0.005) and in serum samples from the P group compared to the normal value (p = 0.005), with sera showing more frequent abnormal results.

Human neurocysticercosis: IgE in cerebrospinal fluid

The detection of IgE is technically difficult because of its reduced concentrations in serum, and even lower concentrations in cerebrospinal fluid (CSF). In the present investigation we studied 86 CSF samples using animmunoenzymatic method with an anti-IgE-alkaline phosphatase conjugate and a fluorigenic substrate. The samples were from three groups: A) 29 patients with neurocysticercosis (NC), B) 36 patients with different neurologic disorders (neurosyphilis, neurotuberculosis, meningitis, tumors, hemorrhage) and C) 21 discharged individuals who had been hospitalized for bacterial meningitis. The results obtained were: A) 0.05 to 3.00 IU/ml (0.76 + 0.79), B) 0.00 to 1.50 IU/ml (0.23 + 0.34) and C) 0.05 to 1.25 IU/ml (0.34 + 0.34). The present results suggest that IgE appears to play a role in the pathogeny of NC and that efforts should be made to standardize a test for the detection of specific IgE antibodies.