Microscopic Review of Nasopharyngeal Swabs as a Means of Benchside Quality Assurance.

OBJECTIVE: Nasopharyngeal swabs (NPS) are the collection modality of choice for reverse-transcription polymerase chain reaction (RT-PCR) multiplex array for respiratory viruses. NPS gather both extracellular material and human respiratory epithelial cells and, when used with RT-PCR, have reliable sensitivity for detection of viral infection. GOALS: At our institution, we identified a 1.7% re-order rate within 7-days for NPS destined for RT-PCR respiratory pathogen multiplex, which we hypothesize may be due in part to low confidence in adequate collection. We sought an inexpensive and accessible strategy for benchside quality assurance of NPS adequacy by observing microscopic content of viral transport media. PROCEDURE: For eight-hundred one NPS samples collected during routine clinical practice in November 2019, aliquots of viral transport media were air-dried and safranin-stained on glass slides under a fume hood. We then counted morphologically distinct ciliated columnar epithelial cells (CCEs), which are prevalent in the nasopharynx. RESULTS: Twenty percent of samples negative for respiratory pathogens by RT-PCR (BioFire FilmArray RP2, Cepheid GeneXpert) had no CCEs, while just seven percent of positive samples had no CCEs. Pearson's Chi-squared test was used to compare presence of CCEs between samples that were positive and negative for respiratory pathogens by RT-PCR (p=1.6×10-36). CONCLUSION: We posit that samples without identifiable CCEs have a greater likelihood of inadequate collection. The basic, benchside protocol that we describe here demonstrates potential to reduce unnecessary re-testing when deployed to confirm negative tests despite high clinical suspicion: a strategy which may help conserve NPS reagents.

Association Between Exposure of Ipratropium and Salmeterol and Diagnosis of Multiple Sclerosis: A Matched Case-control Study.

PURPOSE: Ipratropium and salmeterol were found to stimulate oligodendrocyte differentiation in a high-throughput drug screening assay; thus, they may play a role in the risk reduction of multiple sclerosis (MS). So far, they have not been examined in any clinical data. This study aims at investigating the association between ipratropium and salmeterol and reduced diagnosis of MS with the use of real-world clinical data. METHODS: We conducted a 1:10 matched case-control study that compared the exposure of ipratropium and salmeterol between patients with MS and control patients over the past 2 years, using the MS Flowsheet Registry of OSF HealthCare Saint Francis Medical Center. Cases were matched to control patients, based on service year/quarter, age, sex, race, and payer type. The relationship was examined with a Poisson regression model and a generalized structural equation model. FINDINGS: The sample in our analysis included 217 patients with MS and 2164 matched control patients. The mean (SD) age for both patients with MS and control patients was 41 (11.8) years with a range of 18 to 75 years. The MS group had consistently less prescriptions of ipratropium and salmeterol than the control group in the past 1, 2, and 3 years before the index date. Our multivariable analysis found that the control group had 3.2 more prescriptions (95% CI, 1.4-7.1; P = 0.006) of either ipratropium or salmeterol in the past 2 years than the MS group, even if controlling for other confounders. In the generalized structural equation model, we found that use of ipratropium and salmeterol was significantly associated with reduced diagnosis of MS (P = 0.036), whereas smokers and people with family history of MS were more likely to have a diagnosis of MS (P < 0.001). IMPLICATIONS: The observed association between ipratropium and salmeterol use and reduced diagnosis of MS indicates that they might potentially serve as agents in the treatment of MS.