Detection of antigen and antibody in childhood tuberculous meningitis

Objective Mycobacterium tuberculosis excretory secretory 31 kDa, a serine protease antigen (M. tb ES-31), prepared fromMycobacterium tuberculosis H₃₇Ra culture medium has been shown to have potential in detecting tuberculosis. Precise diagnosis and management of tuberculous meningitis, in children in particular, is essential to curtail mortality and morbidity. Methods In this study, M. tb ES-31 antigen, was used in Indirect ELISA to detect tuberculous IgG antibody, in sera and CSF samples while affinity purified anti ES-31 goat antibody was used in sandwich ELISA for detection of tuberculous antigen. In sixty-five samples each of CSF and sera from cases with neurotuberculosis and control with non-tuberculous diseases were collected from Kasturba Hospital, Sevagram. Results Among the 20 patients suffering from neurotuberculosis the IgG antibody was detected in 17(85%) of CSF and 16(80%) of sera samples, while antigen was detected in 18 (90%) in CSF and 16 (80%) in sera. Overall specificity of the assay for both IgG antibody and antigen detection in CSF was 96% while in sera it was 94% for IgG antibody and 96% for antigen detection. Conclusion This study showed the usefulness of mycobacterial serine protease antigen and its antibody in detecting neurotuberculosis.     

Bacterial antigen detection test in meningitis

Objective : To evaluate the role of bacterial antigen detection test in cerebrospinal fluid (CSF) for a rapid etiological diagnosis of bacterial meningitis.Methods : The study included 36 cases of bacterial meningitis and 14 controls. Latex particle agglutination test (LPA test) for detection of bacterial antigen was done in the CSF using slidex meningitis kit (Biomeriux, France).Results : Using LPA test, an etiological diagnosis could be made in 83% cases of bacterial meningitis. In contrast, CSF Gram stain and culture showed 36% and 6% positivity, respectively. The sensitivity and specificity of LPA test were 83% and 100%, respectively. The common etiological organisms were S.pneumoniae, H. influenzae type b andN. meningitidis A. S. pneumoniae was encountered in all age groups whileH. influenzae type b was found only below one year of age.Conclusions : LPA test is a rapid and superior diagnostic tool as compared to CSF Gram stain and culture. The study recommends LPA test as an adjunct laboratory test for rapid etioiogical diagnosis of bacterial meningitis for prompt institution of proper antibiotics.     

Detection of tubercule antigen in cerebrospinal fluids by ELISA for diagnosis of tuberculous meningitis

An Enzyme Linked Immunosorbent Assay (ELISA) was standardised to detect the presence of tubercule antigen in cerebrospinal fluids from patients with meningitis. CSF samples from clinically suspected cases of tuberculous meningitis, culture proven pyogenic meningitis and non-bacterial aseptic central nervous system (CNS) disorders were tested by ELISA to demonstrate its potential utility for routine diagnostic purpose. Tubercule antigen was detected in 73% cases of tuberculous meningitis and was absent in pyogenic and other non-bacterial CNS disorder cases. The test appears to be a promising approach for a definitive diagnosis of tuberculous meningitis.