Shared Clavulanate and Tazobactam Antigenic Determinants Activate T-Cells from Hypersensitive Patients.

ß-Lactamase inhibitors such as clavulanic acid and tazobactam were developed to overcome ß-lactam antibiotic resistance. Hypersensitivity reactions to these drugs have not been studied in detail, and the antigenic determinants that activate T-cells have not been defined. The objectives of this study were to (i) characterize clavulanate- and tazobactam-responsive T-cells from hypersensitive patients, (ii) explore clavulanate and tazobactam T-cell crossreactivity, and (iii) define the antigenic determinants that contribute to T-cell reactivity. Antigen specificity, pathways of T-cell activation, and crossreactivity with clavulanate- and tazobactam-specific T-cell clones were assessed by proliferation and cytokine release assays. Antigenic determinants were analyzed by mass spectrometry-based proteomics methods. Clavulanate- and tazobactam-responsive CD4+ T-cell clones were stimulated to proliferate and secrete IFN-γ in an MHC class II-restricted and dose-dependent manner. T-cell activation with clavulanate- and tazobactam was dependent on antigen presenting cells because their fixation prevented the T-cell response. Strong crossreactivity was observed between clavulanate- and tazobactam-T-cells; however, neither drug activated ß-lactam antibiotic-responsive T-cells. Mass spectrometric analysis revealed that both compounds form multiple antigenic determinants with lysine residues on proteins, including an overlapping aldehyde and hydrated aldehyde adduct with mass additions of 70 and 88 Da, respectively. Collectively, these data show that although clavulanate and tazobactam are structurally distinct, the antigenic determinants formed by both drugs overlap, which explains the observed T-cell cross-reactivity.

Musculoskeletal tuberculosis in Bradford : 12 years of outcomes and observations in a high-incidence region of the UK.

AIMS: Tuberculosis (TB) is one of the biggest communicable causes of mortality worldwide. While incidence in the UK has continued to fall since 2011, Bradford retains one of the highest TB rates in the UK. This study aims to examine the local disease burden of musculoskeletal (MSK) TB, by analyzing common presenting factors within the famously diverse population of Bradford. METHODS: An observational study was conducted, using data from the Bradford Teaching Hospitals TB database of patients with a formal diagnosis of MSK TB between January 2005 and July 2017. Patient data included demographic data (including nationality/date of entry to the UK), disease focus, microbiology, and management strategies. Disease incidence was calculated using population data from the Office for National Statistics. Poisson confidence intervals were calculated to demonstrate the extent of statistical error. Disease incidence and nationality were also analyzed, and correlation sought, using the chi-squared test. RESULTS: Between January 2005 and July 2017, 109 cases of MSK TB were diagnosed in Bradford. Mean incidence was 1.65 per 100,000 population, per calendar year (SD 0.75). A total of 38 cases required surgical intervention. Low rates of antimicrobial resistance were encountered. A low rate of loss to follow-up was observed (four patients; 3.7%). Overall, 94.5% of patients (n = 103) were successfully treated. 67% of patients (n = 73) reported their country of origin as either India, Pakistan, or Bangladesh. These ethnicities account for around 25% of the local population. CONCLUSION: Bradford maintains a high prevalence of MSK TB infection relative to national data; the prevalence within the local immigrant population remains grossly disproportionate. Typical associated factors (HIV/hepatitis coinfection, drug resistance), have only modest prevalence in our dataset. However, local socioeconomic factors such as deprivation and poverty appear germane as suggested by global literature. We advocate a high degree of suspicion in treatment of atypical infection in any area with similar population factors to ensure timely diagnosis. Cite this article: Bone Jt Open 2022;3(5):432-440.

Noninvasive Ventilation in Cystic Fibrosis: Clinical Indications and Outcomes in a Large UK Adult Cystic Fibrosis Center.

BACKGROUND: Noninvasive ventilation (NIV) is routinely used to treat patients with cystic fibrosis and respiratory failure. However, evidence on its use is limited, with no data on its role in disease progression and outcomes. The aim of this study was to assess the indications of NIV use and to describe the outcomes associated with NIV in adults with cystic fibrosis in a large adult tertiary center. METHODS: A retrospective analysis of data captured prospectively on the unit electronic patient records was performed. All patients with cystic fibrosis who received NIV over a 10-y period were included in the study. A priori, 2 groups were identified based on length of follow-up, with 2 subgroups identified based on duration of NIV treatment. RESULTS: NIV was initiated on 64 occasions. The duration of follow-up was categorized as > 6 months or < 6 months in 31 (48.4%) and 33 (51.6%) occasions, respectively. The most common indications for starting NIV were chronic (48.5%) and acute (32.8%) hypercapnic respiratory failure. Among those with a follow-up > 6 months, subjects who stopped using NIV early showed a steady median (interquartile range) decline in FEV1 (pre-NIV: -0.04 [-0.35 to 0.03] L/y vs post-NIV: -0.07 [-0.35 to 0.01] L/y, P = .51), while among those who continued using it had an improvement in the rate of decline (pre-NIV: -0.25 [-0.52 to -0.02] L/y vs post-NIV: -0.07 [-0.13 to 0.16] L/y, P = .006). No differences in intravenous antibiotic requirement or pulmonary exacerbations were noted with the use of NIV. Pneumothorax and massive hemoptysis occurred independently in 4 cases. CONCLUSIONS: NIV is being used in cystic fibrosis as adjunct therapy for the management of advanced lung disease in a similar fashion to other chronic respiratory conditions. Adherence to NIV treatment can stabilize lung function but does not reduce pulmonary exacerbations or intravenous antibiotic requirement.

Cell Membrane Transporters Facilitate the Accumulation of Hepatocellular Flucloxacillin Protein Adducts: Implication in Flucloxacillin-Induced Liver Injury.

Flucloxacillin is a ß-lactam antibiotic associated with a high incidence of drug-induced liver reactions. Although expression of HLA-B*57:01 increases susceptibility, little is known about the pathological mechanisms involved in the induction of the clinical phenotype. Irreversible protein modification is suspected to drive the reaction through the presentation of flucloxacillin-modified peptides by the risk allele. In this study, the binding of flucloxacillin to proteins of liver-like cells was characterized. Flucloxacillin was shown to bind to proteins localized in bile canaliculi regions, coinciding with the site of clinical disease. The localization of flucloxacillin was mediated primarily by the membrane transporter multidrug resistance-associated protein 2. Modification of multiple proteins by flucloxacillin in bile canaliculi regions may provide a potential local source of neo-antigens for HLA presentation in the liver.

Identification of Flucloxacillin-Haptenated HLA-B*57:01 Ligands: Evidence of Antigen Processing and Presentation.

Flucloxacillin is a ß-lactam antibiotic associated with a high incidence of drug-induced liver reactions. Although expression of human leukocyte antigen (HLA)-B*57:01 increases susceptibility, little is known of the pathological mechanisms involved in the induction of the clinical phenotype. Irreversible protein modification is suspected to drive the reaction through the modification of peptides that are presented by the risk allele. In this study, the binding of flucloxacillin to immune cells was characterized and the nature of the peptides presented by HLA-B*57:01 was analyzed using mass spectrometric-based immunopeptidomics methods. Flucloxacillin modification of multiple proteins was observed, providing a potential source of neoantigens for HLA presentation. Of the peptides eluted from flucloxacillin-treated C1R-B*57:01 cells, 6 putative peptides were annotated as flucloxacillin-modified HLA-B*57:01 peptide ligands (data are available via ProteomeXchange with identifier PXD020137). To conclude, we have characterized naturally processed drug-haptenated HLA ligands presented on the surface of antigen presenting cells that may drive drug-specific CD8+ T-cell responses.

Current and future management of non-tuberculous mycobacterial pulmonary disease (NTM-PD) in the UK.

A rising number of non-tuberculous mycobacterial (NTM) isolates are being identified in UK clinical practice. There are many uncertainties around the management of non-tuberculous mycobacterial pulmonary disease (NTM-PD), including its epidemiology, diagnosis, treatment and prevention. Regional variations in how patients with NTM-PD are managed reflects the lack of standardised pathways in the UK. Service optimisation and multidisciplinary working can improve the quality of care for patients with NTM-PD, including (1) better identification of patients at risk of NTM-PD and modification of risk factors where applicable; (2) standardisation of reference laboratory testing to offer clinicians access to accurate and prompt information on NTM species and drug sensitivities; (3) development of recognised specialist NTM nursing care; (4) standardisation of NTM-PD imaging strategies for monitoring of treatment and disease progression; (5) establishment of a hub-and-spoke model of care, including clear referral and management pathways, dedicated NTM-PD multidisciplinary teams, and long-term patient follow-up; (6) formation of clinical networks to link experts who manage diseases associated with NTM; (7) enabling patients to access relevant support groups that can provide information and support for their condition; and (8) development of NTM research groups to allow patient participation in clinical trials and to facilitate professional education.

Different CFTR modulator combinations downregulate inflammation differently in cystic fibrosis.

Previously, we showed that serum and monocytes from patients with CF exhibit an enhanced NLRP3-inflammasome signature with increased IL-18, IL-1ß, caspase-1 activity and ASC speck release (Scambler et al. eLife 2019). Here we show that CFTR modulators down regulate this exaggerated proinflammatory response following LPS/ATP stimulation. In vitro application of ivacaftor/lumacaftor or ivacaftor/tezacaftor to CF monocytes showed a significant reduction in IL-18, whereas IL-1ß was only reduced with ivacaftor/tezacaftor. Thirteen adults starting ivacaftor/lumacaftor and eight starting ivacaftor/tezacaftor were assessed over three months. Serum IL-18 and TNF decreased significantly with treatments, but IL-1ß only declined following ivacaftor/tezacaftor. In (LPS/ATP-stimulated) PBMCs, IL-18/TNF/caspase-1 were all significantly decreased and IL-10 was increased with both combinations. Ivacaftor/tezacaftor alone showed a significant reduction in IL-1ß and pro-IL-1ß mRNA. This study demonstrates that these CFTR modulator combinations have potent anti-inflammatory properties, in addition to their ability to stimulate CFTR function, which could contribute to improved clinical outcomes.

Towards a more precise diagnosis of hypersensitivity to beta-lactams - an EAACI position paper.

A recent survey of the European Academy of Allergy and Clinical Immunology (EAACI) Drug Allergy Interest Group (DAIG) on how European allergy specialists deal with beta-lactam (BL) hypersensitivity demonstrated a significant heterogeneity in current practice, suggesting the need to review and update existing EAACI guidelines in order to make the diagnostic procedures as safe and accurate, but also as cost-effective, as possible. For this purpose, a bibliographic search on large studies regarding BL hypersensitivity diagnosis was performed by an EAACI task force, which reviewed and evaluated the literature data using the GRADE system for quality of evidence and strength of recommendation. The updated guidelines provide a risk stratification in BL hypersensitivity according to index reaction(s), as well as an algorithmic approach, based on cross-reactivity studies, in patients with a suspicion of BL hypersensitivity and an immediate need for antibiotic therapy, when referral to an allergist is not feasible. Furthermore, the update addresses availability and concentrations of skin test (ST) reagents, ST and drug provocation test (DPT) protocols, and diagnostic algorithms and administration of alternative BL in allergic subjects. Specifically, distinct diagnostic algorithms are suggested depending on risk stratification of the patient into high and low risk based on the morphology and chronology of the reaction, immediate (ie, occurring within 1-6 hours after the last administered dose) or nonimmediate (ie, occurring more than 1 hour after the initial drug administration), and the reaction severity. Regarding the allergy workup, the main novelty of this document is the fact that in some low-risk nonimmediate reactions ST are not mandatory, especially in children. For DPT, further studies are necessary to provide data supporting the standardization of protocols, especially of those regarding nonimmediate reactions, for which there is currently no consensus.

Definition of Haptens Derived from Sulfamethoxazole: In Vitro and in Vivo.

Hypersensitivity reactions occur frequently in patients upon treatment with sulfamethoxazole (SMX). These adverse effects have been attributed to nitroso sulfamethoxazole (SMX-NO), the reactive product formed from auto-oxidation of the metabolite SMX hydroxylamine. The ability of SMX-NO to prime naïve T-cells in vitro and also activate T-cells derived from hypersensitive patients has illustrated that T-cell activation may occur through the binding of SMX-NO to proteins or through the direct modification of MHC-bound peptides. SMX-NO has been shown to modify cysteine residues in glutathione, designer peptides, and proteins in vitro; however, the presence of these adducts have not yet been characterized in vivo. In this study a parallel in vitro and in vivo analysis of SMX-NO adducts was conducted using mass spectrometry. In addition to the known cysteine adducts, multiple SMX-NO-derived haptenic structures were found on lysine and tyrosine residues of human serum albumin (HSA) in vitro. On lysine residues two haptenic structures were identified including an arylazoalkane adduct and a Schiff base adduct. Interestingly, these adducts are labile to heat and susceptible to hydrolysis as shown by the presence of allysine. Furthermore, SMX-modified HSA adducts were detected in patients on long-term SMX therapy illustrated by the presence of an arylazoalkane adduct derived from a proposed carboxylic acid metabolite of SMX-NO. The presence of these adducts could provide an explanation for the immunogenicity of SMX and the strong responses to SMX-NO observed in T-cell culture assays. Also, the degradation of these adducts to allysine could lead to a stress-related innate immune response required for T-cell activation.

A EAACI drug allergy interest group survey on how European allergy specialists deal with ß-lactam allergy.

An accurate diagnosis of ß-lactam (BL) allergy can reduce patient morbidity and mortality. Our aim was to investigate the availability of BL reagents, their use and test procedures in different parts of Europe, as well as any differences in the diagnostic workups for evaluating subjects with BL hypersensitivity. A survey was emailed to all members of the EAACI Drug Allergy Interest Group (DAIG) between February and April 2016, and the questionnaire was meant to study the management of suspected BL hypersensitivity. The questionnaire was emailed to 82 DAIG centres and answered by 57. Amoxicillin alone or combined to clavulanic acid were the most commonly involved BL except in the Danish centre, where penicillin V was the most frequently suspected BL. All centres performed an allergy workup in subjects with histories of hypersensitivity to BL: 53 centres (93%) followed DAIG guidelines, two national guidelines and two local guidelines. However, there were deviations from DAIG recommendations concerning allergy tests, especially drug provocation tests. A significant heterogeneity exists in current practice not only among countries, but also among centres within the same country. This suggests the need to re-evaluate, update and standardize protocols on the management of patients with suspected BL allergy.

Level of accuracy of diagnoses recorded in discharge summaries: A cohort study in three respiratory wards.

RATIONALE: One of the key functions of the discharge summary is to convey accurate diagnostic description of patients. Inaccurate or missing diagnoses may result in a false clinical picture, inappropriate management, poor quality of care, and a higher risk of re-admission. While several studies have investigated the presence or absence of diagnoses within discharge summaries, there are very few published studies assessing the accuracy of these diagnoses. The aim of this study was to measure the accuracy of diagnoses recorded in sample summaries, and to determine if it was correlated with the type of diagnoses (eg, "respiratory" diagnoses), the number of diagnoses, or the length of patient stay. METHODS: A prospective cohort study was conducted in three respiratory wards in a large UK NHS Teaching Hospital. We determined the reference list of diagnoses (the closest to the true state of the patient based on consultant knowledge, patient records, and laboratory investigations) for comparison with the diagnoses recorded in a discharge summary. To enable objective comparison, all patient diagnoses were encoded using a standardized terminology (ICD-10). Inaccuracy of the primary diagnosis alone and all diagnoses in discharge summaries was measured and then correlated with type of diseases, number of diagnoses, and length of patient stay. RESULTS: A total of 107 of 110 consecutive discharge summaries were analysed. The mean inaccuracy rate per discharge summary was 55% [95% CI 52 to 58%]. Primary diagnoses were wrong, inaccurate, missing, or mis-recorded as a secondary diagnosis in half the summaries. The inaccuracy rate was correlated with the type of disease but not with number of diagnoses nor length of patient stay. CONCLUSION: Our study showed that diagnoses were not accurately recorded in discharge summaries, highlighting the need to measure and improve discharge summary quality.

Management of adverse reactions to first-line tuberculosis antibiotics.

PURPOSE OF REVIEW: Tuberculosis (TB) is the commonest infectious cause of death globally. Adverse reactions to first-line tuberculosis antibiotics are common and have a major impact on the outcomes of patients as second-line antibiotics are less effective and more toxic. The present review addresses the most recent literature regarding epidemiology, investigating reactions, and reintroducing treatment in patients who have had their treatment interrupted. RECENT FINDINGS: Studies have demonstrated that up to 60% of patients experience adverse reactions to TB treatment; around a third of these are idiosyncratic and may relate to immune sensitization. There is an increased risk in patients with HIV. For patients with severe cutaneous reactions patch testing has an important role; however, systemic reactions to patch testing are common in patients with HIV. In-vitro testing remains limited to specialist centers but studies have identified drug-specific lymphocyte responses in patients with cutaneous and liver reactions. Desensitization of patients with severe cutaneous reactions have been demonstrated to be possible, albeit at high risk. SUMMARY: Management of these patients remains suboptimal. Better identification of predisposing factors, such as HLA alleles, are needed to identify patients at risk. Improved in-vitro diagnostics will reduce the need to re-expose the patient to the drug and optimized desensitization regimens will improve patient safety when drugs have to be re-introduced.

The impact of three discharge coding methods on the accuracy of diagnostic coding and hospital reimbursement for inpatient medical care.

BACKGROUND: Coding of diagnoses is important for patient care, hospital management and research. However coding accuracy is often poor and may reflect methods of coding. This study investigates the impact of three alternative coding methods on the inaccuracy of diagnosis codes and hospital reimbursement. METHODS: Comparisons of coding inaccuracy were made between a list of coded diagnoses obtained by a coder using (i)the discharge summary alone, (ii)case notes and discharge summary, and (iii)discharge summary with the addition of medical input. For each method, inaccuracy was determined for the primary, secondary diagnoses, Healthcare Resource Group (HRG) and estimated hospital reimbursement. These data were then compared with a gold standard derived by a consultant and coder. RESULTS: 107 consecutive patient discharges were analysed. Inaccuracy of diagnosis codes was highest when a coder used the discharge summary alone, and decreased significantly when the coder used the case notes (70% vs 58% respectively, p < 0.0001) or coded from the discharge summary with medical support (70% vs 60% respectively, p < 0.0001). When compared with the gold standard, the percentage of incorrect HRGs was 42% for discharge summary alone, 31% for coding with case notes, and 35% for coding with medical support. The three coding methods resulted in an annual estimated loss of hospital remuneration of between £1.8 M and £16.5 M. CONCLUSION: The accuracy of diagnosis codes and percentage of correct HRGs improved when coders used either case notes or medical support in addition to the discharge summary. Further emphasis needs to be placed on improving the standard of information recorded in discharge summaries.

Up-Regulation of T-Cell Activation MicroRNAs in Drug-Specific CD4+ T-Cells from Hypersensitive Patients.

Dysregulation in the expression of microRNAs (miRNAs), single-stranded RNAs which regulate gene expression, has been associated with diseases such as Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN), although their cellular origin has not been explored. Thus, the focus of this work was to study expression patterns of reported miRNAs involved in T-cell activation following drug-specific stimulation in peripheral blood mononuclear cells (PBMCs) and drug-specific CD4+ T-cell clones (TCC) from patients with different cutaneous manifestations of delayed-type drug hypersensitivity reactions. CD4+ T-cells from hypersensitive patients were stimulated to proliferate, secreted cytokines (IFN-γ and IL-22), cytolytic molecules (Granzyme B) and up-regulate miRNAs 24 to 48 h after drug exposure. Carbamazepine-specific CD4+ T-cells that proliferated to the greatest extent and secreted the highest levels of IFN-γ showed an up-regulation of miR-18a and miR-155. In contrast, piperacillin-specific CD4+ T-cells displaying high expression of miR-9 and miR-21 showed an association with the extent of proliferation, but not IFN-γ secretion. MiR-155 up-regulation was detected in PBMCs from all hypersensitive patients 24 h after drug treatment, while miR-18a and miR-21 expression was up-regulated after 48 h. These findings demonstrate that miRNAs are expressed during drug-specific CD4+ T-cell activation and shows a new regulation path for drug hypersensitivity reactions.