Development and Evaluation of AccuPower COVID-19 Multiplex Real-Time RT-PCR Kit and AccuPower SARS-CoV-2 Multiplex Real-Time RT-PCR Kit for SARS-CoV-2 Detection in Sputum, NPS/OPS, Saliva and Pooled Samples

Rapid and accurate detection of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential for the successful control of the current global COVID-19 pandemic. The real-time reverse transcription polymerase chain reaction (Real-time RT-PCR) is the most widely used detection technique. This research describes the development of two novel multiplex real-time RT-PCR kits, AccuPower® COVID-19 Multiplex Real-Time RT-PCR Kit (NCVM) specifically designed for use with the ExiStation™48 system (comprised of ExiPrep™48 Dx and Exicycler™96 by BIONEER, Korea) for sample RNA extraction and PCR detection, and AccuPower® SARS-CoV-2 Multiplex Real-Time RT-PCR Kit (SCVM) designed to be compatible with manufacturers' on-market PCR instruments. The limit of detection (LoD) of NCVM was 120 copies/mL and the LoD of the SCVM was 2 copies/μL for both the Pan-sarbecovirus gene and the SARS-CoV-2 gene. The AccuPower® kits demonstrated high precision with no cross reactivity to other respiratory-related microorganisms. The clinical performance of AccuPower® kits was evaluated using the following clinical samples: sputum and nasopharyngeal/oropharyngeal swab (NPS/OPS) samples. Overall agreement of the AccuPower® kits with a Food and Drug Administration (FDA) approved emergency use authorized commercial kit (STANDARD™ M nCoV Real-Time Detection kit, SD BIOSENSOR, Korea) was above 95% (Cohen's kappa coefficient ≥ 0.95), with a sensitivity of over 95%. The NPS/OPS specimen pooling experiment was conducted to verify the usability of AccuPower® kits on pooled samples and the results showed greater than 90% agreement with individual NPS/OPS samples. The clinical performance of AccuPower® kits with saliva samples was also compared with NPS/OPS samples and demonstrated over 95% agreement (Cohen's kappa coefficient > 0.95). This study shows the BIONEER NCVM and SCVM assays are comparable with the current standard confirmation assay and are suitable for effective clinical management and control of SARS-CoV-2.

Effect of the early diastolic blood pressure response to the head-up tilt test on the recurrence of benign paroxysmal positional vertigo

BACKGROUND

Otolith organ acts complementarily with the autonomic nervous system to maintain blood pressure. However, the effect of blood pressure variability in the autonomic nervous system on otolith organ has not yet been determined. This study aimed to verify the hypothesis that blood pressure variability in the autonomic nervous system affects the recurrence of benign paroxysmal positional vertigo (BPPV), which is the most common disease of the vestibular organs, by using the head-up tilt test (HUTT).

METHODS

This study included 432 patients diagnosed with idiopathic BPPV. The follow-up period for all patients was 12 months. Age, sex, hypertension, diabetes and recurrence were analyzed. The HUTT parameters were divided into a group of patients whose average diastolic blood pressure increased in the upright position compared to supine position during the HUTT (DBP1) and a group of patients whose average diastolic blood pressure decreased in the upright position compared to supine position during the HUTT (DBP2). Model selection, general loglinear analysis, and logit loglinear analysis were performed using a hierarchically progressing loglinear analysis.

RESULTS

In summary, the group with increased average diastolic blood pressure (DBP1) showed a higher tendency for BPPV recurrence compared to the group with decreased diastolic blood pressure (DBP2) in the upright position during the HUTT, although the difference was not statistically significant (p = 0.080). However, in males, the DBP1 group demonstrated a significantly higher recurrence rate of BPPV than the DBP2 group during the HUTT (95% CI, -20.021 to -16.200; p < 0.001).

CONCLUSIONS

It is presumed that poor autonomic nervous system response through vestibulosympathetic reflex maintains elevated diastolic blood pressure in the upright position during the HUTT. This variability is assumed to affect the recurrence of BPPV.

Blood Pressure Response to the Head-Up Tilt Test in Benign Paroxysmal Positional Vertigo

The vestibular organ is involved in controlling blood pressure through vestibulosympathetic reflexes of the autonomic nervous system. This study aimed to investigate the effect of benign paroxysmal positional vertigo (BPPV) on blood pressure control by the autonomic nervous system by observing changes in blood pressure before and after BPPV treatment using the head-up tilt test (HUTT). A total of 278 patients who underwent the HUTT before and after treatment were included. The HUTT measured blood pressure repeatedly on the day of diagnosis and the day of complete recovery, and the results were analyzed using repeated measures analysis of variance. Regarding the difference in the systolic blood pressure of patients with BPPV, the blood pressure at 1, 2, and 3 min in the upright position after complete recovery was significantly lower than before treatment (p = 0.001, p = 0.001, and p = 0.012, respectively). Blood pressure at 1 and 2 min in the diastolic blood pressure of patients with BPPV in the upright position after complete recovery was significantly lower than before treatment (p = 0.001 and p = 0.034, respectively). This study shows that BPPV increases blood pressure during the initial response to standing in the HUTT.

Vitamin D Supplementation and Recurrence of Benign Paroxysmal Positional Vertigo

Positional vertigo manifests as a spinning sensation triggered by changes in head position relative to gravity. Benign paroxysmal positional vertigo (BPPV) is an inner ear disorder characterized by recurrent episodes of positional vertigo. The connection between vitamin D insufficiency/deficiency and the onset and recurrence of BPPV is established. This study aims to assess vitamin D as a recurring factor in BPPV and the efficacy of vitamin D supplementation in preventing its recurrence. A comprehensive literature review on the relationship between vitamin D and BPPV recurrence was conducted, searching PubMed, Embase, Web of Science, and article reference lists for studies published from 2020 to 2023. A total of 79 articles were initially identified through the search, with 12 of them being utilized in the study. Recurrence rates for BPPV varied from 13.7% to 23% for studies with follow-up less than 1 year and 13.3% to 65% for studies with follow-up equal to or exceeding 2 years. Risk factors for BPPV recurrence include advanced age, female sex, hypertension, diabetes mellitus, hyperlipidemia, osteoporosis, and vitamin D deficiency. While earlier studies did not establish a link between low vitamin D levels and initial BPPV occurrence, they did associate recurrent episodes with low vitamin D levels. Recent research indicates that vitamin D supplementation in BPPV patients with deficiency or insufficiency decreases both the numbers of relapsing patients and relapses per patient. To validate these findings across diverse populations, further randomized controlled studies with larger cohorts and extended follow-up durations are essential.

The impact of vestibular-autonomic blood pressure responses derived from the head-up Tilt test on benign paroxysmal positional vertigo recurrence

The autonomic nervous system maintains homeostasis, with the vestibulosympathetic reflex playing a key role in regulating blood pressure during postural changes. Benign paroxysmal positional vertigo (BPPV), a common vestibular disorder, has been linked to autonomic dysfunction, but the impact of vestibular-autonomic interactions on BPPV recurrence remains unclear. This prospective study investigated whether changes in diastolic blood pressure (DBP) responses during head-up tilt tests before and after treatment are associated with BPPV recurrence in 370 patients with idiopathic BPPV. DBP responses were recorded at 1 and 2 min after tilting, and patients were categorized into three groups based on DBP changes. At 6 months, the high-response group in the 1-minute DBP category had a 1.98-fold higher recurrence rate than the low-response group (p = 0.029). At 12 months, this group showed a 9.8-fold higher multiple recurrence rate (p = 0.033), while the high-response group in the 2-minute category had a 14.3-fold higher rate (p = 0.012). These results suggest that elevated DBP responses during vestibulosympathetic reflex activation are significantly associated with BPPV recurrence. Monitoring DBP through head-up tilt tests could provide valuable insights into recurrence risk, highlighting the role of vestibular-autonomic interactions in BPPV.