PIRCHE-II Risk and Acceptable Mismatch Profile Analysis in Solid Organ Transplantation.

To optimize outcomes in solid organ transplantation, the HLA genes are regularly compared and matched between the donor and recipient. However, in many cases a transplant cannot be fully matched, due to widespread variation across populations and the hyperpolymorphism of HLA alleles. Mismatches of the HLA molecules in transplanted tissue can be recognized by immune cells of the recipient, leading to immune response and possibly organ rejection. These adverse outcomes are reduced by analysis using epitope-focused models that consider the immune relevance of the mismatched HLA.PIRCHE, an acronym for Predicted Indirectly ReCognizable HLA Epitopes, aims to categorize and quantify HLA mismatches in a patient-donor pair by predicting HLA-derived T cell epitopes. Specifically, the algorithm predicts and counts the HLA-derived peptides that can be presented by the host HLA, known as indirectly-presented T cell epitopes. Looking at the immune-relevant epitopes within HLA allows a more biologically relevant understanding of immune response, and provides an expanded donor pool for a more refined matching strategy compared with allele-level matching. This PIRCHE algorithm is available for analysis of single transplantations, as well as bulk analysis for population studies and statistical analysis for comparison of probability of organ availability and risk profiles.

Using artificial intelligence and deep learning to optimise the selection of adult congenital heart disease patients in S-ICD screening.

INTRODUCTION: The risk of complications associated with transvenous ICDs make the subcutaneous implantable cardiac defibrillator (S-ICD) a valuable alternative in patients with adult congenital heart disease (ACHD). However, higher S-ICD ineligibility and higher inappropriate shock rates-mostly caused by T wave oversensing (TWO)- are observed in this population. We report a novel application of deep learning methods to screen patients for S-ICD eligibility over a longer period than conventional screening. METHODS: Adult patients with ACHD and a control group of normal subjects were fitted with a 24-h Holters to record their S-ICD vectors. Their T:R ratio was analysed utilising phase space reconstruction matrices and a deep learning-based model to provide an in-depth description of the T: R variation plot for each vector. T: R variation was compared statistically using t-test. RESULTS: 13 patients (age 37.4 ± 7.89 years, 61.5 % male, 6 ACHD and 7 control subjects) were enrolled. A significant difference was observed in the mean and median T: R values between the two groups (p < 0.001). There was also a significant difference in the standard deviation of T: R between both groups (p = 0.04). CONCLUSIONS: T:R ratio, a main determinant for S-ICD eligibility, is significantly higher with more tendency to fluctuate in ACHD patients when compared to a population with normal hearts. We hypothesise that our novel model could be used to select S-ICD eligible patients by better characterisation of T:R ratio, reducing the risk of TWO and inappropriate shocks in the ACHD patient cohort.

The characteristics of the implicit body model of the trunk.

Knowing where the body is in space requires reference to a stored model of the size and shape of body parts, termed the body model. This study sought to investigate the characteristics of the implicit body model of the trunk by assessing the position sense of midline and lateral body landmarks. Sixty-nine healthy participants localised midline and lateral body landmarks on their thorax, waist and hips, with perceived positions of these landmarks compared to actual positions. This study demonstrates evidence of a significant distortion of the implicit body model of the trunk, presenting as a squatter trunk, wider at the waist and hips. A significant difference was found between perceived and actual location in the horizontal (x) and vertical (y) directions for the majority of trunk landmarks. Evidence of a rightward bias was noted in the perception of six of the nine body landmarks in the horizontal (x) direction, including all midline levels. In the vertical (y) direction, a substantial inferior bias was evident at the thorax and waist. The implicit body model of the trunk is shown to be distorted, with the lumbar spine (waist-to-hip region) held to be shorter and wider than reality.

Cyanobacterial α-carboxysome carbonic anhydrase is allosterically regulated by the Rubisco substrate RuBP.

Cyanobacterial CO2 concentrating mechanisms (CCMs) sequester a globally consequential proportion of carbon into the biosphere. Proteinaceous microcompartments, called carboxysomes, play a critical role in CCM function, housing two enzymes to enhance CO2 fixation: carbonic anhydrase (CA) and Rubisco. Despite its importance, our current understanding of the carboxysomal CAs found in α-cyanobacteria, CsoSCA, remains limited, particularly regarding the regulation of its activity. Here, we present a structural and biochemical study of CsoSCA from the cyanobacterium Cyanobium sp. PCC7001. Our results show that the Cyanobium CsoSCA is allosterically activated by the Rubisco substrate ribulose-1,5-bisphosphate and forms a hexameric trimer of dimers. Comprehensive phylogenetic and mutational analyses are consistent with this regulation appearing exclusively in cyanobacterial α-carboxysome CAs. These findings clarify the biologically relevant oligomeric state of α-carboxysomal CAs and advance our understanding of the regulation of photosynthesis in this globally dominant lineage.

Engineering the cyanobacterial ATP-driven BCT1 bicarbonate transporter for functional targeting to C3 plant chloroplasts.

The ATP-driven bicarbonate transporter 1 (BCT1), a four-component complex in the cyanobacterial CO2-concentrating mechanism, could enhance photosynthetic CO2 assimilation in plant chloroplasts. However, directing its subunits (CmpA, CmpB, CmpC and CmpD) to three chloroplast sub-compartments is highly complex. Investigating BCT1 integration into Nicotiana benthamiana chloroplasts revealed promising targeting strategies using transit peptides from the intermembrane space protein Tic22 for correct CmpA targeting, while the transit peptide of the chloroplastic ABCD2 transporter effectively targeted CmpB to the inner envelope membrane. CmpC and CmpD were targeted to the stroma by RecA and recruited to the inner envelope membrane by CmpB. Despite successful targeting, expression of this complex in CO2-dependent Escherichia coli failed to demonstrate bicarbonate uptake. We then used rational design and directed evolution to generate new BCT1 forms that were constitutively active. Several mutants were recovered, including a CmpCD fusion. Selected mutants were further characterized and stably expressed in Arabidopsis thaliana, but the transformed plants did not have higher carbon assimilation rates or decreased CO2 compensation points in mature leaves. While further analysis is required, this directed evolution and heterologous testing approach presents potential for iterative modification and assessment of CO2-concentrating mechanism components to improve plant photosynthesis.

It's OK to Move! Effect of a Brief Video on Community Confidence in Activity Despite Back Pain: A Randomized Trial.

OBJECTIVE: To estimate the difference in confidence to become active despite low back pain in people who were exposed to one of 2 video interventions delivered on social media, compared to no intervention. DESIGN: A proof-of-concept, 3-group randomized controlled trial, in a 1:1:1 ratio. METHODS: Participants aged 18 years and over, with and without low back pain, were recruited via the social media channel Facebook, to view either a humorous video, a neutral video, or to no intervention. The videos were delivered online, explained evidence-based management for low back pain, and were designed to "go viral." The primary outcome was confidence in becoming active despite pain, measured using the Pain Self Efficacy Questionnaire (Item 10) (ranges from 0 [not at all confident] to 6 [completely confident]) immediately after watching the video. We aimed to capture the real-time impact and immediate reactions that contributed to the content's reach. RESULTS: Among 1933 randomized participants (mean [standard deviation] age: 58.9 [14.0] years, 1285 [75%] women), 1232 [70%] had low back pain and 88.8% completed the primary outcome. One thousand two hundred sixty-four participants were randomized to receive a video intervention, and 633 participants did not receive a video. On a 6-point scale, individuals exposed to either video (n = 1088) showed a mean confidence level 0.3 points higher (95% confidence interval: 0.1, 0.6) compared with no video (n = 630). CONCLUSION: Participants who viewed a brief video intervention reported a very small difference in confidence to become active despite low back pain, compared with no intervention. The difference may lack clinical relevance. J Orthop Sports Phys Ther 2024;54(6):1-8. Epub 18 April 2024. doi:10.2519/jospt.2024.12412.

The Fremantle Back Awareness Questionnaire: cross-cultural adaptation, reliability, and validity of the Italian version in people with chronic low back pain.

BACKGROUND AND AIM: There is evidence to suggest that assessing back-specific altered self-perception may be useful when seeking to understand and manage low back pain (LBP). The Fremantle Back Awareness Questionnaire (FreBAQ) is a patient-reported measure of back-specific body perception that has never been adapted and psychometrically analysed in Italian. Hence, the objectives of this research were to cross-culturally adapt and validate the Italian version of this outcome measure (namely, the FreBAQ-I), to make it available for use with Italians suffering from chronic LBP. METHODS: The FreBAQ-I was developed by forward and backward translation, review by a committee skilled in patient-reported measures and test of the pre-final version to assess its clarity, acceptability, and relevance. The statistical analyses examined: structural validity based on Rasch analysis; hypotheses testing by investigating correlations of the FreBAQ-I with the Roland Morris Disability Questionnaire (RMDQ), a pain intensity numerical rating scale (PI-NRS), the Pain Catastrophising Scale (PCS), and the Tampa Scale of Kinesiophobia (TSK) (Pearson's correlations); reliability by internal consistency (Cronbach's alpha) and test-retest repeatability (intraclass correlation coefficient, ICC (2,1)); and measurement error by determining the minimum detectable change (MDC). After the development of a consensus-based translation of the FreBAQ-I, the new outcome measure was delivered to 100 people with chronic LBP. RESULTS: Rasch analysis confirmed the substantial unidimensionality and the structural validity of the FreBAQ-I. Hypothesis testing was considered good as at least 75% of the hypotheses were confirmed; correlations: RMDQ (r = 0.35), PI-NRS (r = 0.25), PCS (r = 0.41) and TSK (r = 0.38). Internal consistency was acceptable (alpha = 0.82) and test-retest repeatability was excellent (ICC (2,1) = 0.88, 95% CI: 0.83, 0.92). The MDC95 corresponded to 6.7 scale points. CONCLUSION: The FreBAQ-I was found to be a unidimensional, valid, and reliable outcome measure in Italians with chronic LBP. Its application is advised for clinical and research use within the Italian speaking community.

PIRCHE application major versions 3 and 4 lead to equivalent T cell epitope mismatch scores in solid organ and stem cell transplantation modules.

PIRCHE scores in organ and stem cell transplantation have been shown to correlate with increased risk of donor-specific HLA antibodies and graft-versus-host disease, respectively. With advancements of the PIRCHE application server, it is critical to compare the predicted scores with previous versions. This manuscript compares the newly introduced PIRCHE version 4.2 with its predecessor version 3.3, which was widely used in retrospective studies, using a virtual cohort of 10,000 transplant pairs. In the stem cell transplantation module, both versions yield identical results in 100% of the test population. In the solid organ module, 97% of the test population has identical PIRCHE scores. The deviating cases (3%) were attributed to refinements in the PIRCHE algorithm's specification. Furthermore, the magnitude of the difference is likely to be below the detection limit for clinical effects, confirming the equivalence in PIRCHE scores between versions 3.3 and 4.2.

A carboxysome-based CO2 concentrating mechanism for C3 crop chloroplasts: advances and the road ahead.

The introduction of the carboxysome-based CO2 concentrating mechanism (CCM) into crop plants has been modelled to significantly increase crop yields. This projection serves as motivation for pursuing this strategy to contribute to global food security. The successful implementation of this engineering challenge is reliant upon the transfer of a microcompartment that encapsulates cyanobacterial Rubisco, known as the carboxysome, alongside active bicarbonate transporters. To date, significant progress has been achieved with respect to understanding various aspects of the cyanobacterial CCM, and more recently, different components of the carboxysome have been successfully introduced into plant chloroplasts. In this Perspective piece, we summarise recent findings and offer new research avenues that will accelerate research in this field to ultimately and successfully introduce the carboxysome into crop plants for increased crop yields.

Tactile localization accuracy at the low back.

Localizing tactile stimulation is an important capability for everyday function and may be impaired in people with persistent pain. This study sought to provide a detailed description of lumbar spine tactile localization accuracy in healthy individuals. Sixty-nine healthy participants estimated where they were touched at nine different points, labelled in a 3 × 3 grid over the lumbar spine. Mislocalization between the perceived and actual stimulus was calculated in horizontal (x) and vertical (y) directions, and a derived hypotenuse (c) mislocalization was calculated to represent the direct distance between perceived and actual points. In the horizontal direction, midline sites had the smallest mislocalization. Participants exhibited greater mislocalization for left- and right-sided sites, perceiving sites more laterally than they actually were. For all vertical values, stimulated sites were perceived lower than reality. A greater inaccuracy was observed in the vertical direction. This study measured tactile localization for the low back utilizing a novel testing method. The large inaccuracies point to a possible distortion in the underlying perceptual maps informing the superficial schema; however, further testing comparing this novel method with an established tactile localization task, such as the point-to-point method, is suggested to confirm these findings.

Repeated local ellipsoid protrusion supplements HLA surface characterization.

Allorecognition of donor HLA is a major risk factor for long-term kidney graft survival. Although several molecular matching algorithms have been proposed that compare physiochemical and structural features of the donors' and recipients' HLA proteins in order to predict their compatibility, the exact underlying mechanisms are still not fully understood. We hypothesized that the ElliPro approach of single ellipsoid fitting and protrusion ranking lacks sensitivity for the characteristic shape of HLA molecules and developed a prediction pipeline named Snowball that is fitting smaller ellipsoids iteratively to substructures. Aggregated protrusion ranks of locally fitted ellipsoids were calculated for 712 publicly available HLA structures and 78 predicted structures using AlphaFold 2. Amino-acid sequence and protrusion ranks were used to train deep neural network predictors to infer protrusion ranks for all known HLA sequences. Snowball protrusion ranks appear to be more sensitive than ElliPro scores in fine parts of the HLA such as the helix structures forming the HLA binding groove in particular when the ellipsoids are fitted to substructures considering atoms within a 15 Å radius. A cloud-based web service was implemented based on amino-acid matching considering both protein- and position-specific surface area and protrusion ranks extending the previously presented Snowflake prediction pipeline.

Report from the extended HLA-DPA1 ~ promoter ~ HLA-DPB1 haplotype of the 18th international HLA and immunogenetics workshop.

The primary goal of the HLA-DPA1 ~ promoter ~ HLA-DPB1 haplotype component of the 18th IHIWS was to characterise the extended haplotypes within the HLA-DP region and survey the extent of genetic diversity in this region across human populations. In this report, we analysed single-nucleotide polymorphisms (SNPs) in 255 subjects from 6 different cohorts. The results from the HLA-DP haplotype component have validated findings from the initial pilot study. SNPs in this region were inherited in strong linkage, particularly HLA-DPA1, SNP-linked promoter haplotypes and motifs in exon 2 of HLA-DPB1. We reported 17 SNP-linked haplotypes in the promoter region. Together with HLA-DPA1 and HLA-DPB1 alleles, they formed 74 distinct extended HLA-DP haplotypes in 438 sequences. We also observed the presence of region-specific alleles and promoter haplotypes. Our approach involved phasing extended SNPs including promoter SNPs, HLA-DPA1 and HLA-DPB1 alleles, in a 22 kb region, GRCh38/hg38 (chr6:33,064,111-33,086,679), followed by clustering of these SNPs as one extended haplotype. This hierarchical clustering revealed four major clades, suggesting that haplotypes within each clade may have diverged from a common ancestral haplotype and undergone similar evolutionary processes. The correlation between HLA-DPA1 and the promoter region raises questions about the role of HLA-DPA1 antigen in the heterodimer. This finding requires validation on a larger sample size specifically designed for anthropological analysis. Nevertheless, the results from this study highlight the clinical potential of selecting better-matched donors for patients awaiting haematopoietic stem cell transplants from genetically overlapping groups that share common ancestral haplotypes.

Plant-based carboxysomes: another step toward increased crop yields.

Synthetically reconstructed carboxysomes form the basis of CO2-concentrating mechanisms (CCMs) that could enhance the photosynthetic efficiency of crops and improve yield. Recently, Chen et al. revealed another step toward the reconstruction of bacterial carboxysomes in plants, reporting the formation of almost-complete carboxysomes in the chloroplast of Nicotiana tabacum.

Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews.

BACKGROUND: Complex regional pain syndrome (CRPS) is a chronic pain condition that usually occurs in a limb following trauma or surgery. It is characterised by persisting pain that is disproportionate in magnitude or duration to the typical course of pain after similar injury. There is currently no consensus regarding the optimal management of CRPS, although a broad range of interventions have been described and are commonly used. This is the first update of the original Cochrane review published in Issue 4, 2013. OBJECTIVES: To summarise the evidence from Cochrane and non-Cochrane systematic reviews of the efficacy, effectiveness, and safety of any intervention used to reduce pain, disability, or both, in adults with CRPS. METHODS: We identified Cochrane reviews and non-Cochrane reviews through a systematic search of Ovid MEDLINE, Ovid Embase, Cochrane Database of Systematic Reviews, CINAHL, PEDro, LILACS and Epistemonikos from inception to October 2022, with no language restrictions. We included systematic reviews of randomised controlled trials that included adults (≥18 years) diagnosed with CRPS, using any diagnostic criteria.  Two overview authors independently assessed eligibility, extracted data, and assessed the quality of the reviews and certainty of the evidence using the AMSTAR 2 and GRADE tools respectively. We extracted data for the primary outcomes pain, disability and adverse events, and the secondary outcomes quality of life, emotional well-being, and participants' ratings of satisfaction or improvement with treatment.  MAIN RESULTS: We included six Cochrane and 13 non-Cochrane systematic reviews in the previous version of this overview and five Cochrane and 12 non-Cochrane reviews in the current version. Using the AMSTAR 2 tool, we judged Cochrane reviews to have higher methodological quality than non-Cochrane reviews. The studies in the included reviews were typically small and mostly at high risk of bias or of low methodological quality. We found no high-certainty evidence for any comparison.  There was low-certainty evidence that bisphosphonates may reduce pain intensity post-intervention (standardised mean difference (SMD) -2.6, 95% confidence interval (CI) -1.8 to -3.4, P = 0.001; I2 = 81%; 4 trials, n = 181) and moderate-certainty evidence that they are probably associated with increased adverse events of any nature (risk ratio (RR) 2.10, 95% CI 1.27 to 3.47; number needed to treat for an additional harmful outcome (NNTH) 4.6, 95% CI 2.4 to 168.0; 4 trials, n = 181).  There was moderate-certainty evidence that lidocaine local anaesthetic sympathetic blockade probably does not reduce pain intensity compared with placebo, and low-certainty evidence that it may not reduce pain intensity compared with ultrasound of the stellate ganglion. No effect size was reported for either comparison. There was low-certainty evidence that topical dimethyl sulfoxide may not reduce pain intensity compared with oral N-acetylcysteine, but no effect size was reported. There was low-certainty evidence that continuous bupivacaine brachial plexus block may reduce pain intensity compared with continuous bupivacaine stellate ganglion block, but no effect size was reported. For a wide range of other commonly used interventions, the certainty in the evidence was very low and provides insufficient evidence to either support or refute their use. Comparisons with low- and very low-certainty evidence should be treated with substantial caution. We did not identify any RCT evidence for routinely used pharmacological interventions for CRPS such as tricyclic antidepressants or opioids. AUTHORS' CONCLUSIONS: Despite a considerable increase in included evidence compared with the previous version of this overview, we identified no high-certainty evidence for the effectiveness of any therapy for CRPS. Until larger, high-quality trials are undertaken, formulating an evidence-based approach to managing CRPS will remain difficult. Current non-Cochrane systematic reviews of interventions for CRPS are of low methodological quality and should not be relied upon to provide an accurate and comprehensive summary of the evidence.

The QuantuMDx Q-POC SARS-CoV-2 RT-PCR assay for rapid detection of COVID-19 at point-of-care: preliminary evaluation of a novel technology.

Accurate and rapid point-of-care (PoC) diagnostics are critical to the control of the COVID-19 pandemic. The current standard for accurate diagnosis of SARS-CoV-2 is laboratory-based reverse transcription polymerase chain reaction (RT-PCR) assays. Here, a preliminary prospective performance evaluation of the QuantuMDx Q-POC SARS-CoV-2 RT-PCR assay is reported. Between November 2020 and March 2021, 49 longitudinal combined nose/throat (NT) swabs from 29 individuals hospitalised with RT-PCR confirmed COVID-19 were obtained at St George's Hospital, London. In addition, 101 mid-nasal (MN) swabs were obtained from healthy volunteers in June 2021. These samples were used to evaluate the Q-POC SARS-CoV-2 RT-PCR assay. The primary analysis was to compare the sensitivity and specificity of the Q-POC test against a reference laboratory-based RT-PCR assay. The overall sensitivity of the Q-POC test compared with the reference test was 96.88% (83.78- 99.92% CI) for a cycle threshold (Ct) cut-off value for the reference test of 35 and 80.00% (64.35-90.95% CI) without altering the reference test's Ct cut-off value of 40. The Q-POC test is a sensitive, specific and rapid PoC test for SARS-CoV-2 at a reference Ct cut-off value of 35. The Q-POC test provides an accurate option for RT-PCR at PoC without the need for sample pre-processing and laboratory handling, enabling rapid diagnosis and clinical triage in acute care and other settings.

Mechanisms of education and graded sensorimotor retraining in people with chronic low back pain: a mediation analysis.

ABSTRACT: An improved understanding of the biopsychosocial influences that contribute to and maintain pain has promoted the development of new efficacious treatments for chronic low back pain (CLBP). This study aimed to investigate the mechanisms of a new treatment-education and graded sensorimotor retraining-on pain and disability. We conducted a preplanned causal mediation analysis of a randomized clinical trial which allocated 276 participants with CLBP to 12 weekly clinical sessions of education and graded sensorimotor retraining (n = 138) or a sham and attention control (n = 138). Outcomes were pain intensity and disability, both assessed at 18 weeks. Hypothesized mediators included tactile acuity, motor coordination, back self-perception, beliefs about the consequences of back pain, kinesiophobia, pain self-efficacy, and pain catastrophizing, all assessed at the end of treatment (12 weeks). Four of 7 mechanisms (57%) mediated the intervention effect on pain; the largest mediated effects were for beliefs about back pain consequences (-0.96 [-1.47 to -0.64]), pain catastrophizing (-0.49 [-0.61 to -0.24]), and pain self-efficacy (-0.37 [-0.66 to -0.22]). Five of 7 mechanisms (71%) mediated the intervention effect on disability; the largest mediated effects were for beliefs about back pain consequences (-1.66 [-2.62 to -0.87]), pain catastrophizing (-1.06 [-1.79 to -0.53]), and pain self-efficacy (-0.84 [-1.89 to -0.45]). When all 7 mechanisms were considered simultaneously, the joint mediation effect explained most of the intervention effect for both pain and disability. Optimizing interventions to target beliefs about the consequences of back pain, pain catastrophizing, and pain self-efficacy is likely to lead to improved outcomes for people with CLBP.

Pharmacological treatments for low back pain in adults: an overview of Cochrane Reviews.

BACKGROUND: Pharmacological interventions are the most used treatment for low back pain (LBP). Use of evidence from systematic reviews of the effects of pharmacological interventions for LBP published in the Cochrane Library, is limited by lack of a comprehensive overview. OBJECTIVES: To summarise the evidence from Cochrane Reviews of the efficacy, effectiveness, and safety of systemic pharmacological interventions for adults with non-specific LBP. METHODS: The Cochrane Database of Systematic Reviews was searched from inception to 3 June 2021, to identify reviews of randomised controlled trials (RCTs) that investigated systemic pharmacological interventions for adults with non-specific LBP. Two authors independently assessed eligibility, extracted data, and assessed the quality of the reviews and certainty of the evidence using the AMSTAR 2 and GRADE tools. The review focused on placebo comparisons and the main outcomes were pain intensity, function, and safety. MAIN RESULTS: Seven Cochrane Reviews that included 103 studies (22,238 participants) were included. There is high confidence in the findings of five reviews, moderate confidence in one, and low confidence in the findings of another. The reviews reported data on six medicines or medicine classes: paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), muscle relaxants, benzodiazepines, opioids, and antidepressants. Three reviews included participants with acute or sub-acute LBP and five reviews included participants with chronic LBP. Acute LBP Paracetamol There was high-certainty evidence for no evidence of difference between paracetamol and placebo for reducing pain intensity (MD 0.49 on a 0 to 100 scale (higher scores indicate worse pain), 95% CI -1.99 to 2.97), reducing disability (MD 0.05 on a 0 to 24 scale (higher scores indicate worse disability), 95% CI -0.50 to 0.60), and increasing the risk of adverse events (RR 1.07, 95% CI 0.86 to 1.33). NSAIDs There was moderate-certainty evidence for a small between-group difference favouring NSAIDs compared to placebo at reducing pain intensity (MD -7.29 on a 0 to 100 scale (higher scores indicate worse pain), 95% CI -10.98 to -3.61), high-certainty evidence for a small between-group difference for reducing disability (MD -2.02 on a 0-24 scale (higher scores indicate worse disability), 95% CI -2.89 to -1.15), and very low-certainty evidence for no evidence of an increased risk of adverse events (RR 0.86, 95% CI 0. 63 to 1.18). Muscle relaxants and benzodiazepines There was moderate-certainty evidence for a small between-group difference favouring muscle relaxants compared to placebo for a higher chance of pain relief (RR 0.58, 95% CI 0.45 to 0.76), and higher chance of improving physical function (RR 0.55, 95% CI 0.40 to 0.77), and increased risk of adverse events (RR 1.50, 95% CI 1. 14 to 1.98). Opioids None of the included Cochrane Reviews aimed to identify evidence for acute LBP. Antidepressants No evidence was identified by the included reviews for acute LBP. Chronic LBP Paracetamol No evidence was identified by the included reviews for chronic LBP. NSAIDs There was low-certainty evidence for a small between-group difference favouring NSAIDs compared to placebo for reducing pain intensity (MD -6.97 on a 0 to 100 scale (higher scores indicate worse pain), 95% CI -10.74 to -3.19), reducing disability (MD -0.85 on a 0-24 scale (higher scores indicate worse disability), 95% CI -1.30 to -0.40), and no evidence of an increased risk of adverse events (RR 1.04, 95% CI -0.92 to 1.17), all at intermediate-term follow-up (> 3 months and ≤ 12 months postintervention). Muscle relaxants and benzodiazepines There was low-certainty evidence for a small between-group difference favouring benzodiazepines compared to placebo for a higher chance of pain relief (RR 0.71, 95% CI 0.54 to 0.93), and low-certainty evidence for no evidence of difference between muscle relaxants and placebo in the risk of adverse events (RR 1.02, 95% CI 0.67 to 1.57). Opioids There was high-certainty evidence for a small between-group difference favouring tapentadol compared to placebo at reducing pain intensity (MD -8.00 on a 0 to 100 scale (higher scores indicate worse pain), 95% CI -1.22 to -0.38), moderate-certainty evidence for a small between-group difference favouring strong opioids for reducing pain intensity (SMD -0.43, 95% CI -0.52 to -0.33), low-certainty evidence for a medium between-group difference favouring tramadol for reducing pain intensity (SMD -0.55, 95% CI -0.66 to -0.44) and very low-certainty evidence for a small between-group difference favouring buprenorphine for reducing pain intensity (SMD -0.41, 95% CI -0.57 to -0.26). There was moderate-certainty evidence for a small between-group difference favouring strong opioids compared to placebo for reducing disability (SMD -0.26, 95% CI -0.37 to -0.15), moderate-certainty evidence for a small between-group difference favouring tramadol for reducing disability (SMD -0.18, 95% CI -0.29 to -0.07), and low-certainty evidence for a small between-group difference favouring buprenorphine for reducing disability (SMD -0.14, 95% CI -0.53 to -0.25). There was low-certainty evidence for a small between-group difference for an increased risk of adverse events for opioids (all types) compared to placebo; nausea (RD 0.10, 95% CI 0.07 to 0.14), headaches (RD 0.03, 95% CI 0.01 to 0.05), constipation (RD 0.07, 95% CI 0.04 to 0.11), and dizziness (RD 0.08, 95% CI 0.05 to 0.11). Antidepressants There was low-certainty evidence for no evidence of difference for antidepressants (all types) compared to placebo for reducing pain intensity (SMD -0.04, 95% CI -0.25 to 0.17) and reducing disability (SMD -0.06, 95% CI -0.40 to 0.29). AUTHORS' CONCLUSIONS: We found no high- or moderate-certainty evidence that any investigated pharmacological intervention provided a large or medium effect on pain intensity for acute or chronic LBP compared to placebo. For acute LBP, we found moderate-certainty evidence that NSAIDs and muscle relaxants may provide a small effect on pain, and high-certainty evidence for no evidence of difference between paracetamol and placebo. For safety, we found very low- and high-certainty evidence for no evidence of difference with NSAIDs and paracetamol compared to placebo for the risk of adverse events, and moderate-certainty evidence that muscle relaxants may increase the risk of adverse events. For chronic LBP, we found low-certainty evidence that NSAIDs and very low- to high-certainty evidence that opioids may provide a small effect on pain. For safety, we found low-certainty evidence for no evidence of difference between NSAIDs and placebo for the risk of adverse events, and low-certainty evidence that opioids may increase the risk of adverse events.