Management Of Chronic Infection Research Articles

B-172 Development and Validation of an LC-MS/MS Assay for Quantification of Glecapravir/Pibrentasvir in Human Plasma

Abstract Background The global prevalence of chronic hepatitis C virus (HCV) infection is 58 million. Untreated chronic HCV infections can lead to serious health complications, including liver cirrhosis, damage, and disease. Direct acting antiviral (DAA) therapies for HCV infections are effective in the treatment and management of chronic infections. Glecapravir (GLE) and pibrentasvir (PIB) are DAAs that may be delivered alone or as a fixed-dose oral formulation to treat adolescent and adult patients with chronic HCV infections (genotypes 1–6) with or without cirrhosis. Here, we describe a liquid chromatographic-tandem mass spectrometric (LC-MS/MS) assay for the multiplexed quantification of GLE and PIB in human plasma, with future applications in clinical trials to evaluate the pharmacokinetics of intramuscularly delivered GLE/PIB. Methods Calibrators were prepared in human K2EDTA plasma at final concentrations ranging from 0.25 to 2000 ng/mL GLE and 0.25 to 1000 ng/mL PIB. Samples at the lower limit of quantification (LLOQ), low, mid, high, and dilution quality control (QC) levels were prepared at 0.25, 0.75, 800, 1800, and 20 000 ng/mL for GLE and 0.25, 0.75, 400, 800 ng/mL, and 10 000 ng/mL for PIB, respectively.Plasma samples containing GLE and PIB were combined with isotopically labeled internal standards and subjected to protein precipitation. Samples were evaporated to dryness, reconstituted in 50:50 mobile phase A (MPA, 0.1% formic acid in water): mobile phase B (MPB, 0.1% formic acid in 80:20 acetonitrile:water) and subjected to LC-MS/MS analysis.Chromatographic separation and analyte quantification occurred on an API 6500+ (Sciex, Foster City, CA) interfaced with an LC-30 (Shimadzu, Kyoto, Japan) operated in positive ionization and selective reaction monitoring modes. Chromatographic separation occurred using a Zorbax Eclipse C18 column under a gradient elution from MPA to MPB. Transitions monitored for analytes of interest were as follows: GLE (839.4 à 684.3 m/z), PIB (557.5 à 871.4 m/z), and their internal standards (GLE -IS 843.5 à 684.3 m/z; PIB-IS 561.5 à 629.3 m/z).The LC-MS/MS assay was validated in accordance with Food and Drug Administration Bioanalytical Method Validation Guidance for Industry recommendations. Results Inter-assay precision and accuracy ranged from 4.34% to 15.6% and −4.90% to 10.6% for GLE and 3.20% to 9.80% and −7.48% to −1.46% for PIB, respectively. GLE and PIB in plasma are stable following six freeze thaw cycles at <−70 °C, with a percent difference (%DIF) ≤±10.8% for GLE and ≤±12.4 for PIB. Additionally, GLE and PIB are stable at room temperature for up to 67 h and demonstrated re-injection stability at 4 °C for up to 101 h (GLE: %DIF ≤±4.1%; PIB %DIF: ≤±7.8%). Matrix effects were assessed quantitatively; negligible percent matrix effects were observed for PIB (106%) and PIB-IS (111%) across the measuring range of the assay. Significant ion suppression was observed for GLE (59.9%) and GLE-IS (63.9%); however, relative matrix effects were <5% between drug and internal standard and deemed acceptable. Other assay validation assessments in alternative matrices were also deemed acceptable. Conclusion An LC-MS/MS method for GLE and PIB quantification in plasma has been developed and validated and may be used in downstream applications to characterize DAA pharmacology for HCV treatment.

Incidence of Hepatocellular Carcinoma in Patient with Elevated Alpha Fetoprotein before DAAS

Background: Management of chronic infection with hepatitis C virus (HCV) with direct acting antivirals (DAAs) agents achieves high virological response. Recently, there is a matter of controversy about occurrence of hepatocellular carcinoma (HCC) following those agents. Objective: This study aimed to evaluate the efficacy of alpha fetoprotein (AFP) in development of HCC following DAAs therapy. Patients and methods: two hundred patients with chronic HCV infection who were eligible for DAAs therapy were recruited. Those patients were followed up for one year following therapy to detect development of HCC. Patients were grouped into either with normal AFP (100 patients) or high AFP (100 patients). Results: Majority (84%) of patients were males with overall mean age of 43.87±12.76 years. There were no significant differences between both groups of patients as regard baseline data. With exception of 4% of patients, all of them reached the sustained virological response (SVR). Frequency of HCC detection was higher among those patients with high AFP (9 (9%) vs 1 (1%); P< 0.001). We found that liver cirrhosis; FIB-4, APRI and AFP were predictors for HCC. AFP had the best diagnostic accuracy for prediction of HCC following DAAs Conclusion: Patients who received DAAs for HCV infection should be regularly screened for development of HCC.

Rotating Hinge Knee Arthroplasty for Revision Prosthetic-Knee Infection: Good Functional Outcomes but a Crucial Need for Superinfection Prevention.

Introduction: Management of chronic infection following total knee arthroplasty (TKA) is challenging. Rotating hinged prostheses are often required in this setting due to severe bone loss, ligamentous insufficiency, or a combination of the two. The nature of the mechanical and septic complications occurring in this setting has not been well-described. The aim of this study was to evaluate patient outcomes using a hinge knee prosthesis for prosthetic knee infections and to investigate risk factors for implant removal.Methods: This was a retrospective cohort study that included all patients treated in our tertiary level referral center between January 2009 and December 2016 for prosthetic knee infection with a hinge knee prosthesis. Only patients with a minimum 2-year of follow-up were included. Functional evaluation was performed using international knee society (IKS) “Knee” and “Function” scores. Survival analysis comparing implant removal risks for mechanical and septic causes was performed using Cox univariate analysis and Kaplan-Meier curves. Risk factors for implant removal and septic failure were assessed.Results: Forty-six knees were eligible for inclusion. The majority of patients had satisfactory functional outcomes as determined by mean IKS scores (mean knee score: 70.53, mean function score: 46.53 points, and mean knee flexion: 88.75°). The 2-year implant survival rate was 89% but dropped to 65% at 7 years follow-up. The risk of failure (i.e., implant removal) was higher for septic etiology compared to mechanical causes. Patients with American society of anesthesiologists (ASA) score>1, immunosuppression, or with peripheral arterial diseases had a higher risk for septic failure. Patients with acute infection according to the Tsukayamaclassification had a higher risk of failure. Of the 46 patients included, 19 (41.3%) had atleast one infectious event on the surgical knee and most of these were superinfections (14/19) with new pathogens isolated. Among pathogens responsible for superinfections (i) cefazolin and gentamicin were both active in six of the cases but failed to prevent the superinfection; (ii) cefazolin and/or gentamicin were not active in eight patients, leading to alternative systemic and/or local antimicrobial prophylaxis consideration.Conclusions: Patients with chronic total knee arthroplasty (TKA) infection, requiring revision using rotating hinge implant, had good functional outcomes but experienced a high rate of septic failure, mostly due to bacterial superinfection. These patients may need optimal antimicrobial systemic prophylaxis and innovative approaches to reduce the rate of superinfection.

Management of Modular Mega-Implant Infection of the Lower Extremity.

Revision arthroplasty involving mega-implants is associated with a high complication rate. In particular, infection is a serious complication of revision arthroplasty of hip and knee joints and has been reported to have an average rate of 18%, and for mega-implants, the range is from 3 to 36%. This study was designed to analyze the strategy of treatment of infection of mega-endoprostheses of the lower extremities in our patient cohort, particularly the management of chronic infection. This was a retrospective study that focused on the results of the treatment of periprosthetic infections of mega-implants of the lower extremities. We identified 26 cases with periprosthetic infections out of 212 patients with 220 modular mega-endoprostheses of the lower extremities who were treated in our department between September 2013 and September 2019. As a reinfection or recurrence, we defined clinical and microbiological recurrences of local periprosthetic joint infections after an antibiotic-free period. In this study, 200 cases out of 220 were investigated. The average follow-up period was approximately 18 months (6 months to 6 years). Endoprosthesis infections after implantation of mega-implants occurred in 26 cases (13%). This group comprised 2 early infections (within the first 4 weeks) and 24 chronic infections (between 10 weeks and 6 years after implantation). Nineteen cases out of the identified 26 cases with infection (73.1%) belong to the group of patients who were operated on due to major bone loss following explantation of endoprosthetic components due to previous periprosthetic joint infection. The remaining seven cases with infection comprised four cases following management of periprosthetic fracture, two cases following treatment of aseptic loosening, and one case following tumor resection. All infections were treated surgically. In all cases, the duration of continuous antibiotic treatment did not exceed 6 weeks. Both cases with early infection were treated by exchanging polyethylene inlays and performing debridement with lavage (two cases). In two (7.7%) cases with chronic infection, one-stage surgery was performed. In all remaining cases with chronic infection (22 cases; 84.6%), explantation of all components and temporary implantation of cement spacers were carried out prior to reimplantation. There is still no gold standard therapeutic regimen for the management of periprosthetic infection of mega-implants, though radical surgical debridement and lavage accompanied by systemic antibiotic therapy are the most important therapeutic tools in all cases of periprosthetic infections, regardless of the time of onset. Further studies are needed to standardize management strategies of such infections. Nevertheless, it is not uncommon for compromises to be made based on the particular condition of the individual.

The evolutionary ecology of molecular replicators.

By reasonable criteria, life on the Earth consists mainly of molecular replicators. These include viruses, transposons, transpovirons, coviruses and many more, with continuous new discoveries like Sputnik Virophage. Their study is inherently multidisciplinary, spanning microbiology, genetics, immunology and evolutionary theory, and the current view is that taking a unified approach has great power and promise. We support this with a new, unified, model of their evolutionary ecology, using contemporary evolutionary theory coupling the Price equation with game theory, studying the consequences of the molecular replicators' promiscuous use of each others' gene products for their natural history and evolutionary ecology. Even at this simple expository level, we can make a firm prediction of a new class of replicators exploiting viruses such as lentiviruses like SIVs, a family which includes HIV: these have been explicitly stated in the primary literature to be non-existent. Closely connected to this departure is the view that multicellular organism immunology is more about the management of chronic infections rather than the elimination of acute ones and new understandings emerging are changing our view of the kind of theatre we ourselves provide for the evolutionary play of molecular replicators. This study adds molecular replicators to bacteria in the emerging field of sociomicrobiology.

Managing Pseudomonas aeruginosa respiratory infections in cystic fibrosis.

The current guidelines and recent clinical research in the management of Pseudomonas aeruginosa respiratory infections in cystic fibrosis (CF) are reviewed. Areas where further research is required will also be highlighted. P. aeruginosa is a key respiratory pathogen in CF. Inhaled tobramycin or colistin is recommended for early eradication to prevent establishment of chronic infection. Other antibiotic options are currently being investigated. The long-term success of eradication strategies is also now being assessed. The use of inhaled antibiotics in the management of chronic P. aeruginosa infection is an area of active investigation. Acute pulmonary exacerbations are still a major cause of morbidity and mortality. Guidelines continue to recommend combination intravenous therapy but further research is required to clarify the advantage of this approach. Multidrug resistance is common and potentially more effective antipseudomonal antibiotics may soon become available. The management of P. aeruginosa respiratory infection in CF remains a challenging area, especially in the setting of multidrug resistance. The role of inhaled antibiotics continues to be expanded. Further research is required in the key areas of eradication and management of chronic infection and acute pulmonary exacerbations to identify those treatments that optimize long-term, clinical benefits.

Diagnosis and Management of Chronic Infection

High-energy penetrating extremity injuries are often associated with severe open fractures that have varying degrees of soft-tissue contamination and tenuous soft-tissue coverage. The result is a relatively high prevalence of chronic osteomyelitis compared with that in civilian trauma patients. Diagnosing chronic osteomyelitis requires a careful history and thorough physical and radiographic examinations. Cross-sectional imaging can help delineate the extent of bony involvement, and scintigraphy can be used as a diagnostic tool and to gauge response to treatment. Clinical staging also directs surgical management. Adequacy of débridement remains the most important clinical predictor of success; thus, adopting an oncologic approach to complete (ie, wide) excision is important. Reconstruction can be safely performed by a variety of methods; however, proper staging and patient selection remain critical to a successful outcome. Although systemic and depot delivery of antibiotics plays a supporting role in the treatment of chronic osteomyelitis, the ideal dosing regimens, and the duration of treatment, remain controversial.

Acute Hematogenous Infection following Total Hip and Knee Arthroplasty

While the management of chronic infection after total hip arthroplasty (THA) and total knee arthroplasty (TKA) has been well described, there is a paucity of information presently available on the management and outcomes of patients treated for an acute hematogenous infection. The purpose of this study is to review our experience with treating acute hematogenous infections.

Effect of oxygen limitation on the in vitro activity of levofloxacin and other antibiotics administered by the aerosol route against Pseudomonas aeruginosa from cystic fibrosis patients

Studies have demonstrated that thickened mucous layers in the lungs of cystic fibrosis (CF) patients contain areas of low oxygen tension. These microaerophilic environments may reduce the activity of aerosol antibiotics used in the management of chronic infection in CF. The aim of this study was to compare the MICs of levofloxacin, tobramycin, amikacin, and aztreonam against Pseudomonas aeruginosa under reference and anaerobic conditions and evaluate the in vitro pharmacodynamics of levofloxacin under aerobic and hypoxic testing conditions. The MICs for 114 isolates of P. aeruginosa from CF patients were determined in cation-adjusted Mueller Hinton broth alone or supplemented with 1% potassium nitrate for anaerobic testing. Levofloxacin time–kill curves were performed under aerobic and hypoxic conditions using strains of P. aeruginosa with elevated efflux pump overexpression and/or target mutations. The MICs of nonmucoid or mucoid P. aeruginosa isolates to levofloxacin incubated under aerobic and anaerobic conditions were similar. In contrast, anaerobic incubation resulted in higher MICs for tobramycin, amikacin, and aztreonam among nonmucoid or mucoid isolates, with ≥4-fold increase in MICs for over 40% of the isolates. Time–kill curves performed in aerobic and hypoxic environments with levofloxacin concentrations attained in CF sputum demonstrated similar activity, approaching a maximum bactericidal effect within 10 min of exposure. Together, these results indicate that the activity of some antibiotics against P. aeruginosa is significantly reduced under conditions relevant to the CF lung environment. In contrast, levofloxacin maintains activity against P. aeruginosa under anaerobic or hypoxic conditions similar to those found in CF microaerophilic environments.

Nebulized colistin causes chest tightness in adults with cystic fibrosis

Nebulized antipseudomonal antibiotics may be useful therapeutic agents in patients with cystic fibrosis (CF) (l-3). Short term studies of nebulized colistin have demonstrated its efficacy in eradicating recently acquired Pseudomonas aeruginosa in children (4) and in the management of chronic infection in adults (5). There is no uniform policy regarding the use of nebulized colistin in different CF centres. In our unit patients infected with P. aeruginosa are candidates for regular therapy with the drug if their requirements for oral or i.v. antibiotics are increasing and their pulmonary function is deteriorating. Each potential candidate is challenged to a standard dose of nebulized colistin and, if immediate side effects are not prohibitive, commences regular therapy with the drug. In stable state we recommend that patients inhale nebulized colistin twicedaily, butduringexacerbationsrequiringi.v. antibiotics that the drug be omitted. We do not use the drug as first line therapy during infective exacerbations. Nebulized colistin causes chest tightness in some patients and may lead to discontinuation of regular therapy (4). In this study we have focused specifically on chest tightness as a reason for discontinuing therapy. Patients able to maintain regular therapy (tolerant) have been compared to those who discontinued or could not begin regular therapy because of chest tightness (intolerant) using three measurements; the degree of bronchoconstriction at colistin challenge, severity of airways disease (% predicted FEV,) and reversibility to bronchodilators in stable state.

Long-term follow-up of a series of infected fractures of the tibia

The management of chronic infection in fractures by a method I described in 1965 which was shown to give a better than 9 out of 10 chance of wound healing, is now shown to offer at least a 6 out of 10 chance of wounds remaining healed for 10 years. Amputation is almost never necessary.

Antibacterial organic acids in chronic urinary tract infection. Use in long-term management.

The management of chronic infections of the urinary tract continues to be one of the vexing problems of contemporary infectious disease. The several reasons for the failure to achieve more satisfactory results in spite of the use of the available antibacterial agents have been summarized elsewhere. 1-3 Among the reasons for failure of treatment have been listed such factors as ( a ) the ineffectiveness of the drug used, ( b ) the action of substances that interfere with the antibacterial activities of the drug used, ( c ) the failure of the drug to achieve eradication of the organism even though the organisms are sensitive to the drug by the usual testing circumstances, either because the organisms are not multiplying or because they are sequestered in the lesions and unavailable to the action of the drug, ( d ) the presence of mixed infections leading to the emergence after treatment of a previously suppressed strain of organism,

Antibiotic therapy in infections of the respiratory tract.

THE INTENTION of this paper is to appraise the value of antibiotic treatment in chronic bronchial infections. Patients with bronchial asthma and pulmonary emphysema frequently suffer from associated chronic bronchitis. In other cases of chronic bronchitis bronchospasm of slight to moderate extent is often present. Similarly, patients with bronchiectasis at times manifest bronchospasm and variable degrees of pulmonary emphysema. The results of treatment of these clinical entities with penicillin, especially by inhalation, and with aureomycin, terramycin, and chloramphenicol (chloromycetin®) will be presented, as well as a preliminary statement of the use of the diethylaminoethyl ester of penicillin. The use of antibiotic drugs in bronchiectasis has been restricted in some clinics to the treatment of febrile episodes and the preparation of these patients for surgery.1Although the management of chronic infection in bronchopulmonary disease poses complex problems, the use of the antibiotic agents and procedures which are now available results in