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* Context.--Moderna (mRNA-1272) and Pfizer (BNT162b2) SARS-CoV-2 vaccines demonstrate favorable safety and efficacy profiles, but direct comparison data are lacking. Objective.--To determine the vaccines' side effect profiles and expected antibody responses. These data may help personalize vaccine selection and identify individuals with a suboptimal vaccine response. Design.--One hundred forty-nine healthy, largely seronegative adults were assigned Moderna (n = 79) or Pfizer (n = 70). Following the second dose, participants completed a survey documenting their side effects. Serum was collected 0 to 4 days prior to dose 2, and 14 [+ or -] 4 days, 30 6 4 days, 90 [+ or -] 10 days, and 180 [+ or -] 20 days after dose 2. Convalescent serum specimens were collected 32 to 54 days from donors after a polymerase chain reaction-confirmed SARS-CoV-2 infection (n = 20). Anti-spike antibodies were measured using the Roche Diagnostics Elecys Anti-SARS-CoV-2 S assay on a Roche cobas e801 instrument. Results.--Participants receiving the Moderna vaccine experienced side effects with greater frequency and severity. Both vaccines elicited a robust antibody response, but median signal was higher in Moderna recipients. Symptom severity decreased with age. Antibody response in Pfizer recipients negatively correlated with age. Antibody response decreased after 6 months (84% reduction in Moderna, 79% Pfizer), but values remained greater than for convalescent donors. Antibody response did not correlate with gender or symptom severity. Conclusions.--Moderna may be preferred in individuals in need of greater immune stimulation (eg, older individuals), whereas Pfizer may be preferred in those concerned about vaccine reactions. Anti-spike antibody signal varies by vaccine, so specific reference intervals will be needed to identify individuals with a suboptimal response., Since its identification as the cause of a novel respiratory pneumonia first documented in Wuhan, China, in December 2019, SARS-CoV-2 has spread rapidly throughout the globe, causing 221 million confirmed [...]

Background: Loperamide (Imodium®), a commonly used anti-diarrheal, is a mu opioid receptor agonist that, like all opioids, reduces gastrointestinal tract peristalsis. Loperamide is considered to have low abuse potential as it does not produce an analgesic or euphoric effect due to low bioavailability and first-pass metabolism. However, reports of individuals misusing loperamide through the use of super-therapeutic doses, alone or in combination with P-glycoprotein and/or CYP450 enzyme inhibitors, is increasing. We hypothesized that loperamide could potentially cross-react with laboratory immunoassay drug screens. Methods: Drug-free urine was spiked with loperamide or its principal metabolite, N-desmethyl loperamide (dLop), and assayed on multiple fentanyl and buprenorphine assays. Fentanyl immunoassay screen-positive results at one institution were examined by high-resolution mass spectrometry (MS) for the presence of loperamide and quantified by liquid chromatography– tandem MS when positive. Results: Loperamide produced positive results on the Thermo DRI Fentanyl and Immunalysis Fentanyl assays at concentrations greater than 5.72 mg/L and 23.7 mg/L. dLop generated positive results for the Thermo DRI and Immunalysis fentanyl assays at concentrations exceeding 6.9 mg/L and 35.7 mg/L. dLop also produced positive buprenorphine results on the Thermo CEDIA buprenorphine assay at concentrations exceeding 12.2 mg/L. High-resolution MS analysis of 225 fentanyl immunoassay positives (Thermo DRI) yielded 5 specimens containing loperamide and/or dLop, 4 of which contained measurable quantities of fentanyl in addition to loperamide/dLop. Conclusions: Laboratories using these assays should be aware of the potential for false-positive screening results due to the presence of high concentrations of loperamide and its metabolite dLop. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to redefine the icterus index cutoff for the Roche Jaffé creatinine method using both conjugated and unconjugated bilirubin on 3 Roche cobas modules (c311, c501, and c701/c702) at laboratories across our hospital network. Methods: Interference was evaluated by adding conjugated bilirubin (as bilirubin conjugate, ditaurate) and unconjugated bilirubin to pooled remnant plasma. The effects of conjugated and unconjugated bilirubin were tested separately to assess the contribution of each species. The magnitude of interference was calculated as both absolute and percentage error with total allowable error limits set at 0.1 mg/dL (8 µmol/L or 8%). Results: Analysis of interference data across the 3 Roche modules did not show bias exceeding our total allowable error limits for plasma creatinine up to a conjugated bilirubin icterus index of 16.2 (approximately 16.2 mg/dL or 277 μmol/L) or an unconjugated bilirubin icterus index of 18.5 (approximately 18.5 mg/dL or 316 μmol/L), the highest concentrations tested. Conclusions: Our results demonstrate that the Roche Jaffé method exhibits acceptable performance in the presence of icterus at icterus indexes above the manufacturer's current recommendations of 5 (approximately 5 mg/dL or 86 μmol/L) and 10 (approximately 10 mg/dL or 171 μmol/L) for conjugated and unconjugated bilirubin, respectively. We have updated the icterus index in our hospital system to 16 for conjugated bilirubin and 18 for unconjugated bilirubin. [ABSTRACT FROM AUTHOR]

Background: Autoimmune encephalitis (AE) is a rare collection of disorders that present with a diverse and often nebulous set of clinical symptoms. Indiscriminate use of multi-antibody panels decreases their overall utility and predictive value. Application of a standardized scoring system may help reduce the number of specimens that generate misleading or uninformative results. Methods: The results of autoimmune encephalopathy, epilepsy, or dementia autoantibody panels performed on serum (n = 251) or cerebrospinal fluid (CSF) (n = 235) specimens from October 9th, 2016 to October 11th, 2019 were collected. Retrospective chart review was performed to calculate the Antibody Prevalence in Epilepsy and Encephalopathy (APE2) score for patients with an antibody above the assay-specific reference interval and to classify results as true or false positive. Results: Of the 486 specimens, 60 (12.3%) generated positive results for any AE antibody (6 CSF and 54 serum). After removing 2 duplicate specimens collected from a single patient, 10 of the remaining 58 were determined to be true positives and 8 contained neural-specific antibodies. Application of the APE2 score revealed that 89% of all true positives and 86% of specimens with neural-specific antibodies had a score ≥4. In contrast, 76% of false positives, 74% of clinically nonspecific antibodies, and 85% of the negative specimens had an APE2 score <4. Conclusion: The APE2 score can improve the diagnostic utility of autoimmune encephalopathy evaluation panels. [ABSTRACT FROM AUTHOR]