Evaluation of Using Direct Viral Transport Medium Samples without Nucleic Acid Isolation for SARS-CoV-2 Diagnosis by RT-PCR.

BACKGROUND: Diagnosis with reverse transcriptase polymerase chain reaction (RT-PCR) test is a very important step for the control of the COVID-19 pandemic. The aim of this study is to compare the RT-PCR results of the samples taken directly from the viral transport medium (VTM) without extraction with the RT-PCR results of two different extraction methods, one automated and the other manual, in the diagnosis of COVID-19. METHODS: Among the respiratory tract samples sent to Sakarya Training and Research Hospital Microbiology Laboratory for COVID-PCR study, 20 negative and 43 positive samples with different cycle threshold (CT) values were included in the study. Both manual nucleic acid isolation with the vNAT isolation kit (Bioeksen, Turkey) and automatic nucleic acid isolation with the EZ1 Virus Mini Kit v2.0 in the isolation device were performed simulta-neously from the patient samples included in the study and the results were compared. RESULTS: The mean Ct values of the samples were found to be 21.58 using manual vNAT as the extraction method, 17.63 using the automated magnetic bead method, and 21.45 in PCR from direct VTM without extraction. When the automatic magnetic beads extraction method was taken as the reference method, the sensitivity of direct PCR was 97.3%, the specificity was 95%, the positive predictive value was 97.3%, and the negative predictive value was 95%. Phi coefficients were found to be 0.927 between vNAT and direct PCR, 1 between vNAT and EZ1, and 0.922 between direct PCR and EZ1. CONCLUSIONS: Direct PCR has advantages such as eliminating RNA extraction and purification steps, providing a shorter detection time, and using less labor and less consumables without reducing the diagnostic accuracy. It is thought that this method can help as a useful process management for the control of the epidemic in countries with limited resources.

Evaluation of spinal involvement in children with mucopolysaccharidosis VI: the role of MRI.

OBJECTIVE: To evaluate spinal MRI features of mucopolysaccharidosis (MPS) VI and to assess the correlation with clinical findings. METHODS: We retrospectively evaluated spinal MRI scans and clinical findings at the time of imaging in 14 patients (8 male, 6 female) with MPS VI. Craniometric measurements were performed and the images were assessed for bony anomalies, spinal stenosis and spinal cord compression. The degree of cervical cord compression was scored and correlated with neurological examination findings at the time of imaging. Vertebral alignment, structural changes in spinal ligaments and intervertebral discs were also assessed. RESULTS: All patients had cervical stenosis due to bony stenosis and thickened retrodental tissue (median: 6.05 mm, range 3.3-8 mm). Retrodental tissue thickness was found to increase with age (p = 0.042). Compressive myelopathy was detected at upper cervical level in 11 (79%) and lower thoracic level in 2 patients (14%). Significant inverse correlation was found between cervical myelopathy scores and neurological strength scores. The most common bony changes were hypo/dysplastic odontoid; cervical platyspondyly with anterior inferior beaking; thoracic posterior end plate depressions and lumbar posterior scalloping. Kyphosis due to retrolisthesis of the beaked lumbar vertebrae and acute sacrococcygeal angulations were other remarkable findings. CONCLUSION: MRI is an essential component in evaluation of spinal involvement in MPS VI, and scanning of the entire spine is recommended to rule out thoracic cord compression. Advances in knowledge: This study provides a detailed description of spinal MRI findings in MPS VI and underlines the role of MRI in management of cord compression.