デジタルPCR による遊離DNA を用いた肺腺癌患者のEGFR 変異解析の検討

広島大学(Hiroshima University)博士(医学)Doctor of Philosophy in Medical Sciencedoctora

Cell-Free DNA Analysis of Epithelial Growth Factor Receptor Mutations in Lung Adenocarcinoma Patients by Droplet Digital PCR

Cell-free DNA (cfDNA) analysis may provide a non-invasive diagnostic approach for lung adenocarcinoma patients. Recently, droplet digital PCR (ddPCR) has been developed as a highly sensitive detection method for a low mutant allele percentage. The ddPCR detection limit for epithelial growth factor receptor (EGFR) mutations was evaluated using cell lines, NCI-H1975 for EGFR L858R point mutation and PC-9 for EGFR E746-A750del. Subsequently, detection of EGFR mutations by ddPCR was performed in tumor DNA (tDNA) and cfDNA samples of 19 lung adenocarcinoma patients whose tumor biopsies were already evaluated for EGFR mutations by clamp PCR (13 of L858R, 3 of E746-750del, and 3 of EGFR negative). In 12 cases, immunohistochemical analysis was performed to quantify the number of EGFR L858R-positive cells rate. EGFR point mutation or deletion were detected in 16 tumor DNA samples. In the measurable cfDNA samples, the rate of detection by ddPCR in cfDNA was 61.5% (8/13) for L858R and 100% (3/3) for E746-A750del. A relative correlation was found between the allele fraction (AF) of tDNA and the number of EGFR L858R-positive cells rate. No correlation was found between the AF of tDNA and AF of cfDNA. In our study, cfDNA mutation detection was not associated with clinicopathological features, but cases with high AF of cfDNA did have metastatic lesions. Our study shows that ddPCR enables cfDNA analysis for EGFR L858R and E746-A750del, with a high detection rate. Therefore, cfDNA analysis using ddPCR may complement to tumor biopsy and is beneficial for precision medicine in lung adenocarcinoma patients

Next-Generation Sequencing pada Kanker Paru

Kanker merupakan penyakit genetik, oleh sebab itu, tata laksana kanker didasarkan pada kelainan atau mutasi genetik yang terjadi pada masing-masing pasien kanker. Next-generation sequencing (NGS) adalah teknologi sekuensing gen dengan sensitivitas dan spesifisitas tinggi, yang dikembangkan untuk mendeteksi lebih dari satu kelainan genetik secara bersamaan dalam sekali pemeriksaan. Teknologi NGS tidak memerlukan banyak materi genetik untuk menghasilkan data besar. Diagnosis kanker paru ditegakkan berdasarkan temuan histolopatologi pada sediaan biopsi yang umumnya diperoleh melalui prosedur bronkoskopi. Sediaan biopsi dari bronkoskopi relatif sedikit sehingga pemeriksaan mutasi genetik yang dapat dilakukan hanya terbatas pada mutasi yang sering (hotspot). Oleh sebab itu, teknologi NGS dapat menjadi metode yang lebih sesuai untuk mengetahui profil mutasi pasien agar tata laksana kanker paru dengan prinsip precision medicine dapat diterapkan.   Next-Generation Sequencing in Lung Cancer Cancer is a genetic disease, hence, it is understandable that cancer management should be based on genetic alterations of each cancer patients. Next-generation sequencing is a high-sensitivity and specificity technology developed to detect multiple gene alterations in a single test that requires only a little amount of genetic materials and yet may generate big data. Lung cancer diagnosis is still based on histopathological findings on a limited biopsy specimen obtained during bronchoscopy. Consequently, genetic detection in lung cancer is often limited to hotspot mutations. Therefore, NGS can be a suitable method for genetic mutation profiling in order to apply precision medicine principle in lung cancer management. &nbsp

Brief psychotic disorder in COVID-19 patient with no history of mental illness

INTRODUCTION: COVID-19 pandemic affects mental health globally. Reports showed the increase of mental illness as a response to the COVID-19 pandemic. However, the correlation between the COVID-19 and mental illness is not fully understood yet. METHODOLOGY: We reported a brief psychotic disorder in a COVID-19 patient with no history of mental illness who was hospitalized in Persahabatan Hospital, Jakarta, Indonesia. RESULTS: Psychotic symptoms appeared five days after COVID-19 onset and laboratory tests showed elevated levels of d-dimer and fibrinogen. CONCLUSIONS: Elevated levels of d-dimer and fibrinogen suggest an ongoing COVID-19-associated coagulopathy that might cause a microdamage in the central nervous system. It might contribute to the manifestation of psychotic symptoms. The correlation between brief psychotic disorder and COVID-19 requires further investigation