Direct hemoperfusion using a polymyxin B-immobilized polystyrene column for COVID-19.

OBJECTIVE: To evaluate the efficacy and safety of direct hemoperfusion using a polymyxin B-immobilized polystyrene column (PMX-DHP) in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive pneumonia patients. METHODS: This study was a case series conducted at a designated infectious diseases hospital. Twelve SARS-CoV-2-positive patients with partial pressure of arterial oxygen/percentage of inspired oxygen (P/F) ratio < 300 were treated with PMX-DHP on two consecutive days each during hospitalization. We defined day 1 as the first day when PMX-DHP was performed. PMX-DHP efficacy was assessed on days 7 and 14 after the first treatment based on eight categories. Subsequently, improvement in P/F ratio and urinary biomarkers on days 4 and 8, malfunctions, and ventilator and extracorporeal membrane oxygenation avoidance rates were also evaluated. RESULTS: On day 14 after the first treatment, disease severity decreased in 58.3% of the patients. P/F ratio increased while urine ß2-microglobulin decreased on days 4 and 8. Cytokine measurement pre- and post-PMX-DHP revealed decreased levels of interleukin-6 and the factors involved in vascular endothelial injury, including vascular endothelial growth factor. Twenty-two PMX-DHPs were performed, of which seven and five PMX-DHPs led to increased inlet pressure and membrane coagulation, respectively. When the membranes coagulated, the circuitry needed to be reconfigured. Circuit problems were usually observed when D-dimer and fibrin degradation product levels were high before PMX-DHP. CONCLUSIONS: Future studies are expected to determine the therapeutic effect of PMX-DHP on COVID-19. Because of the relatively high risk of circuit coagulation, coagulation capacity should be assessed beforehand.

Diagnostic accuracy of direct reverse transcription-polymerase chain reaction using guanidine-based and guanidine-free inactivators for SARS-CoV-2 detection in saliva samples.

This study aimed to evaluate diagnostic accuracy of SARS-CoV-2 RNA detection in saliva samples treated with a guanidine-based or guanidine-free inactivator, using nasopharyngeal swab samples (NPS) as referents. Based on the NPS reverse transcription-polymerase chain reaction (RT-PCR) results, participants were classified as with or without COVID-19. Fifty sets of samples comprising NPS, self-collected raw saliva, and saliva with a guanidine-based, and guanidine-free inactivator were collected from each group. In patients with COVID-19, the sensitivity of direct RT-PCR using raw saliva and saliva treated with a guanidine-based and guanidine-free inactivator was 100.0%, 65.9%, and 82.9%, respectively, with corresponding concordance rates of 94.3% (κ=88.5), 82.8% (κ=64.8), and 92.0% (κ=83.7). Among patients with a PCR Ct value of <30 in the NPS sample, the positive predictive value for the three samples was 100.0%, 80.0%, and 96.0%, respectively. The sensitivity of SARS-CoV-2 RNA detection was lower in inactivated saliva than in raw saliva and lower in samples treated with a guanidine-based than with a guanidine-free inactivator. However, in individuals contributing to infection spread, inactivated saliva showed adequate accuracy regardless of the inactivator used. Inactivators can be added to saliva samples collected for RT-PCR to reduce viral transmission risk while maintaining adequate diagnostic accuracy.

Diagnostic accuracy of nasopharyngeal swab, nasal swab and saliva swab samples for the detection of SARS-CoV-2 using RT-PCR.

BACKGROUND: The current gold standard in coronavirus disease (COVID-19) diagnostics is the real-time reverse transcription-polymerase chain reaction (RT-PCR) assay for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in nasopharyngeal swab (NPS) samples. Alternatively, nasal swab (NS) or saliva swab (SS) specimens are used, although available data on test accuracy are limited. We examined the diagnostic accuracy of NPS/NS/SS samples for this purpose. METHODS: Ten patients were included after being tested positive for SARS-CoV-2 RT-PCR in NPS samples according to the National Institute of Infectious Disease guidelines. In comparison with this conventional diagnostic method, NPS/NS/SS samples were tested using the cobas 6800 systems RT-PCR device. To investigate the usefulness of the cobas method and the difference among sample types, the agreement and sensitivity were calculated. Five to six samples were collected over a total period of 5-6 d from each patient. RESULTS: Fifty-seven sets of NPS/NS/SS samples were collected, of which 40 tested positive for COVID-19 by the conventional method. Overall, the concordance rates using the conventional method were 86.0%/70.2%/54.4% for NPS/NS/SS samples (cobas); however, for samples collected up to and including on Day 9 after disease onset (22 negative and one positive specimens), the corresponding rates were 95.7%/87.0%/65.2%. The overall sensitivity estimates were 100.0%/67.5%/37.5% for NPS/NS/SS samples (cobas). For samples up to 9 d after onset, the corresponding values were 100.0%/86.4%/63.6%. CONCLUSIONS: NS samples are more reliable than SS samples and can be an alternative to NPS samples. They can be a useful diagnostic method in the future.