Evaluation of GeneXpert MTB/RIF assay for direct diagnosis of pulmonary tuberculosis.

OBJECTIVES: To evaluate the performance of GeneXpert MTB/RIF assay for direct diagnosis of pulmonary tuberculosis (PTB).   METHODS: This is a cross-sectional study conducted between October 2013 and February 2016 at Abbassaia Chest Hospital and Ain Shams University Hospital, Cairo, Egypt. Inclusion criteria were adults between 18 and 60 years with suspected PTB and classified into 5 clinical categories based on their clinical, radiological, and laboratory findings:  confirmed TB, probable TB, possible TB, unlikely TB, and not TB. Two sputum samples from each participant were analyzed by GX and the results were compared by conventional culture. RESULTS: In total, 218 participants were enrolled: 71 had confirmed TB; 112, highly probable TB; 20, probable TB; 10, unlikely TB; and 5, no TB. The sensitivity and specificity of the GX assay were 93% and 98.3% respectively. GeneXpert was positive in 93% of confirmed TB and 2.2% of probable TB cases.  CONCLUSIONS: GeneXpert is a rapid and promising technique with good sensitivity (93%) and specificity (98.3%), but it cannot be used as a standalone PTB diagnostic tool. There is a need for more GX evaluation studies in countries with low TB incidence.

The role of microRNA-31 and microRNA-21 as regulatory biomarkers in the activation of T lymphocytes of Egyptian lupus patients.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by familial aggregation and genetic predisposition. MicroRNAs (MiRNAs) serve as critical biomarkers in lupus patients because of their aberrant expression in different SLE stages. The study aimed to investigate the correlation of miR-31 and miR-21 with IL-2 in SLE patients as regulatory biomarkers in the activation of T lymphocytes of Egyptian lupus patients. Quantitative RT-PCR is carried out to estimate the expressions of miR-31 and miR-21, and IL-2 levels were determined using ELISA in plasma of 40 patients with SLE, 20 of their first-degree relatives and 20 healthy controls. The study also determined the systemic lupus erythematosus disease activity index (SLEDAI) score and proteinuria in SLE patients. The results revealed that miR-31 was lower expressed, while miR-21 was high expressed in SLE patients compared to their first-degree relatives and controls. MiR-31 was negatively correlated with SLEDAI and proteinuria in lupus patients, while miR-21 showed positive correlation with them. Also we found that there is a significant positive correlation between miR-31 and IL-2 in SLE patients, while miR-21 was negatively correlated with IL-2 level in patients. In conclusion, the study disclosed a significant association between miR-31 and miR-21 expression with IL-2 level in SLE patients. The regulatory biomarkers of miR-31 and miR-21 might have an impact on regulating IL-2 pathway expression and in turn on the activation of T lymphocytes in SLE.