Do we still need OCBs in MS diagnosis and how many?

BACKGROUND: CSF-specific oligoclonal bands (CSF-OCBs) can be used for dissemination in time (DIT) in the 2017 multiple sclerosis (MS) diagnostic criteria. A cut-off of ≥2 CSF-OCBs was recommended but studies have suggested ≥3 CSF-OCBs may be superior. OBJECTIVES: To assess utility of ≥2 and ≥3 CSF-OCBs as a cut-off for MS diagnosis. METHODS: Paired serum and CSF-OCBs sent to the Walton Centre, UK between July 2018 and June 2020 were included. CSF-OCBs were assessed using isoelectric focussing and reviewed by two blinded raters. Case records were reviewed. RESULTS: Of 1334 paired serum and CSF-OCB requests, 945 cases had sufficient clinical information. More than 1 CSF-OCB was detected in 268/945(28%) cases. Of these, 252 had ≥2 and 230 had ≥3 CSF-OCBs. The sensitivity and specificity for MS with ≥2 and ≥3 CSF-OCBs were 91.7%, 91.2%, 90.2% and 93.8% respectively. Only 3/22 patients with 2 CSF-OCBs had MS. In 25% of patients, CSF-OCBs reduced time to MS diagnosis (median 437.5 days (28-1332)). CONCLUSION: Although cut-offs of ≥2 or ≥3 CSF-OCBs performed similarly well, 2 CSF-OCBs were frequently seen with non-inflammatory pathology. Use of ≥3 CSF-OCBs for MS diagnosis should be considered. CSF analysis reduced time to MS diagnosis by approximately 14 months.

Assessment of the accuracy of estimated free phenytoin concentrations in a mixed patient population.

OBJECTIVES: Phenytoin is an anti-epileptic drug that has a narrow therapeutic index, and therefore requires therapeutic drug monitoring. Only the free fraction is pharmacologically active, and in some cases, accurate determination of the free phenytoin concentration may be essential to prevent phenytoin toxicity. Although it is possible to measure free phenytoin concentration, often only the total concentration is measured, with equations used to estimate the free fraction. Several equations are quoted in the literature with no overall consensus with regard to accuracy. This study aimed to assess the correlation between total and free phenytoin in a mixed patient population, and to compare the accuracy of several different equations used to estimate the free phenytoin concentration. METHODS: Fifty-one serum samples were analysed for total phenytoin, free phenytoin and albumin. The measured free phenytoin concentrations were compared against those estimated using five selected equations, identified through a literature search. RESULTS: This study showed poor correlation between the total and measured free phenytoin concentrations, and between the estimated and measured free concentrations. The overall correlation was concentration-dependent, but a correction factor could not be applied to improve the accuracy consistently. The equations assessed showed wide variability between the estimated and measured free phenytoin concentrations, with several showing a clinically significant negative bias when compared with the measured free fraction. DISCUSSION: This study highlights the disparity of the free phenytoin concentrations generated by the equations. Underestimation of free phenytoin concentrations using these equations may result in phenytoin toxicity, bringing into question the safety of using calculated values for patient management in place of physical measurement of free phenytoin concentration by ultra-performance liquid chromatography tandem mass spectrometry.

Clinicians' Perspectives of Treatment for Lateralization Errors: A Quantitative and Qualitative Study.

PURPOSE: This mixed-methods study aimed to obtain information regarding speech-language pathologists' (SLPs) perspectives about treatment of lateralization errors (LEs), challenges to implementing evidence-based LE treatment practice, and the sources SLPs' use to find evidence to treat LEs. This information can assist our understanding of ways to facilitate the uptake of evidence-based practice into the everyday treatment of clients with this disorder. METHOD: A convergent parallel mixed-methods design was used to collect data from SLPs (N = 214) using 24 questions from an online survey distributed through electronic mailing lists and Speech and Hearing State Associations. Quantitative data were analyzed using frequencies and averages; themes and subthemes of qualitative data were analyzed using a content analysis approach with no a priori codes. Quantitative and qualitative results were compared and integrated. RESULTS: Participants believed that LEs required individualized treatment before the age of 5 years, were largely caused by structural and neuromuscular factors, and required an understanding of orofacial and dental structure and function. Challenges to implementing LE treatment included a lack of skills and knowledge specific to LEs, competing demands on clinicians' time and resources, and a research-practice gap. Sources of evidence frequently used to obtain information about LE treatment were colleagues, trainings, workshops, and American Speech-Language-Hearing Association journals. CONCLUSIONS: Clinicians believe that LE treatment is challenging and requires skill training. Future research in LEs will need to consider the real-world decisions clinicians must make when treating this disorder as well as clinicians' everyday constraints and challenges.

Cerebrospinal fluid total protein cannot reliably distinguish true subarachnoid haemorrhage from other causes of raised cerebrospinal fluid net bilirubin and net oxyhaemoglobin absorbances.

BACKGROUND: In cerebrospinal fluid (CSF) spectrophotometry, if the net bilirubin absorbance (NBA) and net oxyhaemoglobin absorbance (NOA) are both raised with a visible oxyhaemoglobin peak, the revised national guidelines for analysis of CSF bilirubin advise interpreting the results as 'Consistent with subarachnoid haemorrhage (SAH)' regardless of the CSF total protein concentration of the specimen. We wanted to study the range of CSF total protein concentrations found in confirmed SAH to establish if the CSF total protein value can give further guidance on the likelihood of SAH. METHODS: Consecutive cases from five different hospital sites were included if the CSF NBA was greater than 0.007 AU and the NOA was greater than 0.02 AU with a visible oxyhaemoglobin peak. For the cases identified, the laboratory information management system and patient records were interrogated to identify the total protein concentration of the CSF specimen and whether SAH had ultimately been confirmed or excluded by other methods and supporting evidence. RESULTS: Results from 132 patients were included. The CSF total protein range in confirmed SAH was 0.23-3.08 g/L with a median concentration of 0.7 g/L (n = 51). In the SAH excluded group, the CSF total protein range was 0.43-29 g/L with a median concentration of 1.9 g/L (n = 81). CONCLUSIONS: Although confirmed SAH was not associated with the very highest concentrations of CSF total protein, a definite CSF protein cut-off concentration above which SAH could reliably be excluded cannot be recommended.

Potential control of human immunodeficiency virus type 1 asp expression by alternative splicing in the upstream untranslated region.

The negative-sense asp open reading frame (ORF) positioned opposite to the human immunodeficiency virus type 1 (HIV-1) env gene encodes the 189 amino acid, membrane-associated ASP protein. Negative-sense transcription, regulated by long terminal repeat sequences, has been observed early in HIV-1 infection in vitro. All subtypes of HIV-1 were scanned to detect the negative-sense asp ORF and to identify potential regulatory sequences. A series of highly conserved upstream short open reading frames (sORFs) was identified. This potential control region from HIV-1(NL4-3), containing six sORFs, was cloned upstream of the reporter gene EGFP. Expression by transfection of HEK293 cells indicated that the introduction of this sORF region inhibits EGFP reporter expression; analysis of transcripts revealed no significant changes in levels of EGFP mRNA. Reverse transcriptase-polymerase chain reaction analysis (RT-PCR) further demonstrated that the upstream sORF region undergoes alternative splicing in vitro. The most abundant product is spliced to remove sORFs I to V, leaving only the in-frame sORF VI upstream of asp. Sequence analysis revealed the presence of typical splice donor- and acceptor-site motifs. Mutation of the highly conserved splice donor and acceptor sites modulates, but does not fully relieve, inhibition of EGFP production. The strong conservation of asp and its sORFs across all HIV-1 subtypes suggests that the asp gene product may have a role in the pathogenesis of HIV-1. Alternative splicing of the upstream sORF region provides a potential mechanism for controlling expression of the asp gene.