ABSTRACT
INTRODUCTION: Factor XIII (FXIII) deficiency is a rare hemorrhagic disorder whose early diagnosis is crucial for appropriate treatment and prophylactic supplementation in cases of severe deficiency. International guidelines recommend a quantitative FXIII activity assay as first-line screening test. FXIII antigen measurement may be performed to establish the subtype of FXIII deficiency (FXIIID) when activity is decreased. METHODS: The aim of this multicenter study was to evaluate the analytical and diagnostic levels of performance of a new latex immunoassay, K-Assay® FXIII reagent from Stago, for first-line measurement of FXIII antigen. Results were compared to those obtained with the Berichrom® FXIII chromogenic assay for measurement of FXIII activity. Of the 147 patient plasma samples, 138 were selected for analysis. RESULTS: The accuracy was very good, with intercenter reproducibility close to 7%. Five groups were defined on FXIII activity level (<5% (n = 5), 5%-30% (n = 23), 30%-60% (n = 17), 60%-120% (n = 69), above 120% (n = 24)), without statistical differences between activity and antigen levels (P value >0.05). Correlation of the K-Assay® with the Berichrom® FXIII activity results was excellent (r = 0.919). Good agreement was established by the Bland and Altman method, with a bias of +9.4% on all samples, and of -1.4% for FXIII levels lower than 30%. One patient with afibrinogenemia showed low levels of Berichrom® FXIII activity but normal antigen level and clot solubility as expected. CONCLUSIONS: The measurement of FXIII antigen using the K-Assay® is a reliable first-line tool for detection of FXIII deficiency when an activity assay is not available.
Subject(s)
Factor XIII Deficiency/blood , Factor XIII/analysis , Factor XIII/metabolism , Female , France , Humans , MaleABSTRACT
The endogenous or exogenous origin of Staphylococcus aureus, responsible for orthopaedic surgical-site infections (SSI), remains debated. We conducted a multicentre prospective cohort study to analyse the respective part of exogenous contamination and endogenous self-inoculation by S. aureus during elective orthopaedic surgery. The nose of each consecutive patient was sampled before surgery. Strains of S. aureus isolated from the nose and the wound, in the case of SSI, were compared by antibiotypes or pulsed-field gel electrophoresis (PFGE). A total of 3,908 consecutive patients undergoing orthopaedic surgery were included. Seventy-seven patients developed an SSI (2%), including 22 related to S. aureus (0.6%). S. aureus was isolated from the nose of 790 patients (20.2%) at the time of surgery. In the multivariate analysis, S. aureus nasal carriage was found to be a risk factor for S. aureus SSI in orthopaedic surgery. However, only nine subjects exhibiting S. aureus SSI had been found to be carriers before surgery: when compared, three pairs of strains were considered to be different and six similar. In most cases of S. aureus SSI, either an endogenous origin could not be demonstrated or pre-operative nasal colonisation retrieved a strain that was different from the one recovered from the surgical site.
Subject(s)
Carrier State/epidemiology , Carrier State/microbiology , Staphylococcal Infections/transmission , Staphylococcus aureus/classification , Surgical Wound Infection/epidemiology , Surgical Wound Infection/microbiology , Aged , Bacterial Typing Techniques , DNA Fingerprinting , Electrophoresis, Gel, Pulsed-Field , Female , Genotype , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Molecular Epidemiology , Prospective Studies , Risk Factors , Staphylococcal Infections/microbiology , Staphylococcus aureus/isolation & purificationABSTRACT
Pro bio Qual Association of Lyon have proposed a control which include the control for detecting benzodiazepines (BZD) and tricyclic antidepressants (ADT) since 2000. With this control, we have evaluated the specificity and the sensitivity of techniques used. We have tested the maprotiline reactivity too (tetracyclic antidepressant). We report results achieved with different immunoassay methods and their performances: specificity and sensitivity. The number of laboratories which realize these analyses is constant: these laboratories are hospital laboratories. Two methods are most common used: the fluorescence polarization immunoassay (FPIA) and the enzyme multiplied immunoassay test (EMIT). The evolution of these techniques does square with the evolution of chemistry analysers used in hospital laboratories. For the BZD, the specificity is good. For the ADT, carbamazepine at low concentration (5 mg/L) gives a positive result with FPIA Abbott assay; carbamazepine at high concentration (25 mg/L) gives a negative result with EMIT assay; phenothiazines give a positive response. For the BZD, the analyser Integra gives best results of sensitivity. Results of sensitivity obtained with the kit EMIT DAU are better than results obtained with the kit EMIT Serum. For the ADT, results of sensitivity obtained with FPIA Abbott assay seem better; the adaptation of EMIT assay on Integra analyser gives less good results. The reactivity for the BZD is very different: we can ignore a severe intoxication with alprazolam or lorazepam (response << cut off) but we can give a positive result for a therapeutic concentration of diazepam for example. With ADT, we haven't the same problem. But the reactivity for nortriptyline is less good than the reactivity for amitriptyline. So we should use a "cut off" concentration which corresponds to the best sensitivity and the best specificity.
Subject(s)
Antidepressive Agents, Tricyclic/blood , Benzodiazepines/blood , Blood Chemical Analysis/methods , Blood Chemical Analysis/standards , Humans , Sensitivity and Specificity , Time FactorsABSTRACT
Serum digoxin measurement is often performed in medical laboratories. A professional association specialized in quality control, based in Lyon, has been organizing punctual controls of medication measurement for the past ten years. The results are analysed in term of intra and inter-technique precision, difference between methods and specificity in regard to endogenous or exogenous interfering substances. Methods have changed with a quasi disappearance of the methods used ten years ago (FPIA, EMIT) and introduction of new technologies on recent immunoanalysis automates. The results observed with the different instruments are similar. Reproductibility has not changed over ten years. Some difficulties remain in the measurement of low concentrations of digoxin. Many substances interfere in digoxin measurement : digoxigenine (inactive metabolite), endogenous digoxin-like immunoreactive factors, spironolacton, antidigoxin antibodies used for treatment of digitalic intoxications. These interferences depend on the method which is used, but it is essential to know them in order to interpret the results correctly.
Subject(s)
Clinical Laboratory Techniques/standards , Digoxin/blood , Humans , Quality Control , Time FactorsABSTRACT
In 1999, in Rhône-Alpes region, in a survey of resistance to antibiotics of Streptococcus pneumoniae, 35 cases of meningitis were observed. A retrospectic questionnary was sent to each participant. MICs to Penicillin, Amoxicillin and Cefotaxime were determined with ATB-PNEUMO gallery or E-test and by disk diffusion for the other antibiotics. The results were interpreted according to the recommendations of the CA-SFM. Mean age was 38.1 years (range : 1 month -78 years) and sex-ratio 2/5. Eight patients had previously received antibiotics, 22 patients had risk factors and 23 were transferred in intensive care unit. The patients received C3G + glycopeptide in 15 of 16 children and in 13/19 adults according to the consensus recommendations. Diagnostic was made on the direct examination of CSF in 83%, and blood cultures was positive in 74.3% of cases. The percentage of PRP was 48.6% with 17.1% of intermediate-amoxicilline and 14.3% intermediate-cefotaxime strains. Resistance to trimethoprim-sulfamethoxazole was 45.7%, to chloramphenicol 30% and to fosfomycin 6.9%. All the strains were susceptible to rifampicin and vancomycin. Among the 17 PRP strains, 7 were belonging to serotype 6 (6 in children). The clinical outcome was fatal in 7 male cases (20%), without risk factors in 3 children and 6 of 7 strains were susceptible to penicillin. Six patients (17%) had auditive and/or neurologic sequellaes. This study shows that nearly 50% of strains isolated in meningitis, in Rhône-Alpes region, were not susceptible to penicillin, and confirms the frequency of sequellaes while the mortality is not related with the resistance of strains to the antibiotics.
Subject(s)
Meningitis, Pneumococcal/epidemiology , Adolescent , Adult , Aged , Amoxicillin/administration & dosage , Cefotaxime/administration & dosage , Child , Child, Preschool , Chloramphenicol , Drug Resistance, Microbial , Female , Fosfomycin , France/epidemiology , Humans , Infant , Male , Meningitis, Pneumococcal/diagnosis , Meningitis, Pneumococcal/drug therapy , Microbial Sensitivity Tests , Middle Aged , Penicillins/administration & dosage , Retrospective Studies , Rifampin/administration & dosage , Surveys and Questionnaires , Trimethoprim, Sulfamethoxazole Drug Combination , Vancomycin/administration & dosageABSTRACT
Screening by ofloxacin disk was carried out on 1158 strains of Streptococcus pneumoniae in order to investigate the in vitro bacteriostatic activity of penicillin G, levofloxacin, moxifloxacin, telithromycin, linezolid, pristinamycin and quinupristin-dalfopristin against ofloxacin-intermediate and -resistant S. pneumoniae strains. It was concluded that these new antimicrobial agents could be useful for the treatment of pneumococcal infections caused by penicillin-sensitive and -resistant S. pneumoniae, and would represent a valid therapeutic option for patients allergic to beta-lactams, should they prove to be potent in vivo.
Subject(s)
Anti-Bacterial Agents/pharmacology , Aza Compounds , Fluoroquinolones , Ketolides , Levofloxacin , Macrolides , Ofloxacin/pharmacology , Quinolines , Streptococcus pneumoniae/drug effects , Virginiamycin/analogs & derivatives , Acetamides/pharmacology , Anti-Infective Agents/pharmacology , Drug Resistance, Bacterial , Lactams/immunology , Linezolid , Microbial Sensitivity Tests , Moxifloxacin , Ofloxacin/immunology , Oxazolidinones/pharmacology , Penicillin G/pharmacology , Pristinamycin/pharmacology , Streptococcus pneumoniae/pathogenicity , Virginiamycin/pharmacologyABSTRACT
In 1999, during the survey of resistance of Streptococcus pneumoniae to antibiotics by 31 clinical laboratories of Rhône-Alpes area, MIC to penicillin (P), amoxicillin (AMX) and cefotaxime (CTX) of 877 PRP strains or with a diameter of inhibition to oxacillin inferior to 26 mm, were determined by each institution by E-test (n = 220 strains) or ATB-PNEUMO (n = 657 strains). MICs of these three antibiotics were determined by dilution in agar medium by the coordinating center. The essential agreement was respectively for ATB-PNEUMO and E-test 89% versus 84% for P (p > 0.05), of 86% vs 79% for AMX (p < 0.01), and of 91% vs 86% for CTX (p = 0.03). When the strains were classified in clinical category, the differences were significant (p < 0.001) for AMX (85% vs 71%) and for CTX (82% vs 75%) but not for P (73% vs 78%). ATB-PNEUMO method was more sensitive than E-test for the detection of strains susceptible to P (90 vs 73%), to AMX (83 vs 78%) and to CTX (80 vs 72%) and for the strains intermediate to AMX (90 vs 78%). On the contrary, E-test is more specific than ATB-PNEUMO for the detection of P-resistant strains (94 vs 86%). Finally, the specificity of both methods is the same for detection of P-S, AMX-R and CTX-I strains.
Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance , Microbial Sensitivity Tests/methods , Reagent Kits, Diagnostic , Streptococcus pneumoniae/drug effects , Amoxicillin/pharmacology , Cefotaxime/pharmacology , Chi-Square Distribution , Humans , Oxacillin/pharmacology , Penicillin Resistance , Pneumococcal Infections/microbiology , Reference Standards , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
Throughout 1996, 22 hospital-based laboratories in the Rhône-Alpes region of France collected pneumococcal strains and used a standardized protocol to record the following data; patient age and sex; type of specimen; and determination of susceptibility to at least the following antibiotics: oxacillin 1 microgram and 5 micrograms, erythromycin (Ery), tetracycline (Tet), chloramphenicol (Chl), rifampin (Rmp), and loracarbef. For penicillin-nonsusceptible strains (PNSSs), which were identified based on results with oxacillin, MICs for penicillin G, amoxicillin (Amx), and cefotaxime (Ctx) were determined using the E Test, at the study site and agar dilution at the coordinating center. Of the 1153 strains, 65.5% were from adults and 31.8% from children; patient age was unknown in 2.7% of cases. PNSPs (MIC > 0.06 mg/l) contributed 32.9% of strains (I: 23.3%; R: 9.6%) and were more common in children (41.1%) than in adults (28.1%). The frequency of PNSSs varied across specimen types: 27.9% in blood cultures (305 strains), 15.6% in cerebrospinal fluid (32), 38.7% in protected bronchopulmonary specimens (31), 31.5% in unprotected bronchopulmonary specimens (434), 50.8% in acute otitis media (118), and 34.4% in other specimens (221). Among PNSSs, nonsusceptibility (I + R) to other antibiotics was variable: Ery, 62.1%; Tet, 41.5%; Chl, 40.4%; Rmp, 1.1%. Corresponding figures for the overall strain population were Ery, 33.3%; Tet, 22.7%; Chl, 22.8%; Rmp, 0.9%. In addition, 56.5% of PNSSs exhibited multiple drug resistance. Resistance to amoxicillin (MIC > 2 mg/l) was demonstrated for only 5 strains. No strains were resistant to loracarbef or cefotaxime. Serotypes of the 379 PNSSs were as follows: 23F, 26.6%; 14 (25.6%); 9V (18.2%), 6 (8.7%), 15 (5%), 19 (4.5%).
Subject(s)
Anti-Bacterial Agents/pharmacology , Microbial Sensitivity Tests/standards , Pneumococcal Infections/drug therapy , Pneumococcal Infections/microbiology , Streptococcus pneumoniae/classification , Adult , Child , Drug Resistance, Microbial , Drug Resistance, Multiple , Female , France , Humans , Laboratories/standards , Male , Quality Assurance, Health Care , Specimen Handling/methods , Streptococcus pneumoniae/drug effects , Streptococcus pneumoniae/isolation & purificationABSTRACT
In 1996-1997 a multicentre study was carried out on 450 Streptococcus pneumoniae strains to compare the MICs and susceptibility categories obtained with the Etest (AB Biodisk) used under routine conditions in 22 hospital laboratories in the Rhône-Alpes region, France, with those obtained by the reference technique of agar dilution performed in a single coordinating centre. Each laboratory detected penicillin resistant pneumococci (PRP) by the oxacillin disk method (1 microgram and 5 micrograms) and determined the MICs of penicillin G (PG), amoxycillin (AMX) and cefotaxime (CTX) by the Etest. All the PRP strains were collected in the coordinating centre where MICs were carried out. The strains were classified as susceptible (S), intermediate (I) and resistant (R) according to the CASFM criteria (Comité de l'Antibiogramme de la Société Française de Microbiologie). The concordance results based on susceptibility categories are as follows: PG = 67.6%, AMX = 63.6%, CTX = 71.5%. Minor errors are as follows: PG = 31.2%, AMX = 36%, CTX = 28.5%. Major and very major errors are rare (0% to 0.6%). Agreement within 1 log2 dilution was obtained for about 80% of the strains. The minor errors results from strains clustering near the breakpoints 1 mg/l (PG) and 0.5 mg/l (AMX, CTX), and from practical difficulties in routine use of the Etest. These discrepancies may result in severe therapeutic problems. This study confirms the limits of the Etest. The authors insist on standardization and rigorous use of the Etest under routine conditions.
Subject(s)
Amoxicillin/pharmacology , Cefotaxime/pharmacology , Cephalosporin Resistance , Microbial Sensitivity Tests/methods , Penicillin G/pharmacology , Penicillin Resistance , Streptococcus pneumoniae/drug effects , Culture Media , Diffusion , Evaluation Studies as Topic , False Negative Reactions , False Positive Reactions , Microbial Sensitivity Tests/standards , Quality Control , Reproducibility of ResultsABSTRACT
Quadriceps femoris muscle needle biopsies were performed in 21 patients with chronic obstructive lung disease (COLD) and acute respiratory failure (ARF) and in 21 age-matched healthy control subjects. Muscle samples were analysed to obtain intracellular bicarbonate and pH values from total acid-labile carbon dioxide content. Muscle potassium, magnesium and sodium content were also determined, as well as water compartments. Skeletal muscle of COLD patients with ARF showed intracellular acidosis and reduced potassium and magnesium content. Total muscle water increase was linked to extracellular water increment. It was concluded that in COLD patients with ARF an overall derangement of skeletal muscle metabolism is present.