Correlation of epidermal growth factor receptor mutation status in plasma and tissue samples of patients with non-small cell lung cancer.

BACKGROUND: Somatic mutations of the gene encoding epidermal growth factor receptor (EGFR) are detected in approximately 30%-50% of patients with non-small cell lung cancers (NSCLC), so detection of EGFR mutation is the pivotal step of treatment in patients with advanced NSCLC. However, difficulty in obtaining sufficient tissue and bias from the heterogeneity of the tumor samples are the major obstacles. Although analyzing EGFR with circulating tumor DNA (ctDNA) in plasma is a breakthrough, accuracy is the problem in variable methods. Peptide nucleic acid (PNA) clamping-assisted fluorescence melting curve analysis (PANAMutyper®) is a novel and highly sensitive method of detecting EGFR mutation in tumor tissues. AIMS AND OBJECTIVES: This study was designed to evaluate PANAMutyper® for detecting EGFR mutation with ctDNA of patients with lung cancer. MATERIALS AND METHODS: EGFR mutation status detected by PNA clamp with tissue samples and by PANAMutyper® with ctDNA was compared. Tissue biopsy was done in 158 patients with lung tumor, in which 23 cases were excluded and 135 cases were enrolled. EGFR mutation rate was 23.0% (31/135) in overall patients. All the plasma samples of the cases with mutant EGFR in tissue samples were verified by an already known highly sensitive method of droplet digital polymerase chain reaction (ddPCR). RESULTS: The concordance rate of tissue and plasma samples was 91.9% (124/135). The sensitivity, specificity, negative predictive value, and positive predictive value were 64.5%, 100%, 90.4%, and 100%, respectively, according to the tissue samples as a standard. PANAMutyper® method was not inferior to ddPCR for the detection of EGFR mutation including T790M with ctDNA. These results suggest that the detection of EGFR mutation status using ctDNA in plasma by PANAMutyper® is a feasible test prior to tissue biopsy.

Role of the neutrophil-lymphocyte count ratio in the differential diagnosis between pulmonary tuberculosis and bacterial community-acquired pneumonia.

BACKGROUND: Differential diagnosis between pulmonary tuberculosis (TB) and bacterial community-acquired pneumonia (CAP) is often challenging. The neutrophil-lymphocyte count ratio (NLR), a convenient marker of inflammation, has been demonstrated to be a useful biomarker for predicting bacteremia. We investigated the usefulness of the NLR for discriminating pulmonary TB from bacterial CAP in an intermediate TB-burden country. METHODS: We retrospectively analyzed the clinical and laboratory characteristics of 206 patients suspected of having pulmonary TB or bacterial CAP from January 2009 to February 2011. The diagnostic ability of the NLR for differential diagnosis was evaluated and compared with that of C-reactive protein. RESULTS: Serum NLR levels were significantly lower in patients with pulmonary TB than in patients with bacterial CAP (3.67±2.12 vs. 14.64±9.72, P<0.001). A NLR <7 was an optimal cut-off value to discriminate patients with pulmonary TB from patients with bacterial CAP (sensitivity 91.1%, specificity 81.9%, positive predictive value 85.7%, negative predictive value 88.5%). The area under the curve for the NLR (0.95, 95% confidence interval [CI], 0.91-0.98) was significantly greater than that of C-reactive protein (0.83, 95% CI, 0.76-0.88; P=0.0015). CONCLUSIONS: The NLR obtained at the initial diagnostic stage is a useful laboratory marker to discriminate patients with pulmonary TB from patients with bacterial CAP in an intermediate TB-burden country.

Liver cirrhosis as a delayed complication of Stevens-Johnson syndrome.

A 26-year-old woman was referred to our department due to fever and skin rash after having taken medication for a common cold. Physical examination revealed erythematous skin changes on her body associated with mucosal involvement in her eyes and oral cavity. Peripheral blood examination revealed leukopenia and thrombocytopenia. Liver function test showed hyperbilirubinemia. She was managed with high dose intravenous immunoglobulin (IVIG) at 1.0 gm/kg of body weight infused for 5 consecutive days. Although the patient's skin lesion improved dramatically with IVIG therapy, her hyperbilirubinemia aggravated progressively. Eighteen months after her presentation, liver cirrhosis was diagnosed by ultrasonography, laboratory and liver biopsy findings.