Rapid diagnosis of tuberculous meningitis by ligase chain reaction amplification.

A total of 87 cerebrospinal fluid (CSF) samples obtained from 85 patients with suspected meningitis were examined for the presence of Mycobacterium tuberculosis by means of ligase chain reaction amplification (LCx; Abbott Laboratories). The results were compared with direct smear and culture results. Of 61 patients with pathological CSF, 9 (14.8%) were scheduled to receive treatment for tuberculous meningitis. The sensitivity of the smear and culture tests was 11.1 and 33.3%, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of the LCx assay were 55.5, 100, 100 and 92.9%, respectively. The results reveal that amplification by ligase chain reaction is valuable for the diagnosis of tuberculous meningitis.

[Assessment of 4 commercial immunoenzymatic assays for the serologic diagnosis of Helicobacter pylori infection]. / Evaluación de cuatro enzimoinmunoanálisis comerciales para el diagnóstico serológico de la infección por Helicobacter pylori.

BACKGROUND: The aim of this study was to evaluate four commercial tests for the serologic diagnosis of infection by Helicobacter pylori based on the detection of IgG class antibodies versus this microorganism. METHODS: Four commercial kits were analyzed based on the ELISA method in serum samples of 48 patients admitted for digestive endoscopy. The data of the serologic tests were compared with those provided by the culture, the histologic observation and the urease test of gastric biopsy specimens. The calculation of seroprevalence of anti-H. pylori antibodies in serum of 60 asymptomatic subjects was carried out. RESULTS: The seroprevalence of infection by H. pylori in an asymptomatic population of between 18 to 78 years of age was 58.33%. A sensitivity of 94.3% and a specificity of 88.9% were observed with the Pyloriset EIA-G test. The positive predictive value (PPV) was 92.2% and the negative predictive value (NPV) 91.5%. With the Chemifarma commercial kit the sensitivity was 78.8% and the specificity 100% with a PPV of 100% and NPV of 76.7%. Plate showed a sensitivity of 85.3% and a specificity of 87.5% with a PPV of 90% and a NPV of 80.76%. Milenia had a sensitivity of 80% and a specificity of 66.7% and a PPV of 77% and a NPV of 70.7%. CONCLUSIONS: The usefulness of the serologic tests for the diagnosis of Helicobacter pylori infection is herein confirmed with the test evaluated showing a high sensitivity and specificity as well as high predictive values.