[A Case of Heparin-Induced Thrombocytopenia with Discrepancy in the Results of Anti-Platelet Factor 4/Heparin Antibodies between Latex-Particle-Enhanced Immunoturbidimetric Assay and Enzyme Immunoassay].

A female patient in her seventies with diabetes mellitus, hyper-lipidemia and mitral regurgitation was admitted because of the acute heart failure. She was treated with diuretics and vasodilators, however these were not effective. Therefore the CHDF using heparin was required for the patients. After the introduction of CHDF, the platelet count subsequently decreased to less than 7.0 x 10(4)/µl. After stopping CHDF, the platelet count recovered. In the second CHDF treatment, the platelet count decreased again. HIT was suspected because of both the usage of heparin and five points of 4T's score in the patient. Heparin was discontinued immediately and then her platelet count improved. The HIT antibody by latex-particle-enhanced immunoturbidimetric assay was performed simultaneously, however it was not detected. After re-using heparin by heparin lock, platelet count had been decreasing. Furthermore the thrombus was observed in the infusion tube. We considered that a clinical course did not accord with the result of HIT antibody. We measured HIT antibody by another method, an enzyme immunoassay (EIA), and the positive antibody was observed. We encountered a rare case with discrepancy in the results of HIT antibody between two methods. When HIT is suspected by the results from the clinical course and 4T's score, even though the negative HIT antibody, heparin should be discontinued and the different assay for HIT antibody such as an EIA in this case should be performed.

[The basic research on the high-sensitive troponin I assay, and the application to evaluation of chronic heart failure].

The mortality among patients with heart diseases increases steadily in an aging society like Japan. Among those, the patients with chronic heart failure (CHF) are thought to be increasing rapidly although the official report is missing. It is well-known that BNP or NT-proBNP is useful for a clinical diagnosis of CHF, but a role of the cardiac troponin (cTn) attracts attention as a novel biomarker of their prognosis. However, because the level of cTn in patients with CHF is far lower than that in cases of acute coronary syndrome (ACS), development of the high-sensitive method with precision is desired. In the present study, a new sensitive assay system with an analyzer, ARCHITECT STAT (cTnI hs-ARCH) was basically studied and found more sensitive than other conventional 2 sensitive methods. The performance of cTnI hs-ARCH was evaluated in patients with CHF by comparing it to findings with other 2 methods. When CHF patients are allocated into categories of NYHA classification according to their subjective symptoms, cTnI hs-ARCH was superior to other methods in discriminating subgroups. In addition, multivariable analysis disclosed that cTnI hs-ARCH is influenced by the level of renal function at the minimum among the 3 methods. Therefore, cTnI hs-ARCH may be a useful method for evaluation of prognosis in patients with CHF who often have impaired renal function.

[Performance and clinical utility of a high-sensitivity troponin T assay].

In the present study, we evaluated the performance and clinical utility of a high-sensitivity troponin T (hs-cTnT) assay. The within- and between-assay variations (coefficients of variation: CV) in the low and high concentrations of troponin T in serum samples were 0.84% to 3.34%, respectively. Analysis of interferents showed that only hemoglobin negatively influenced the assay results. Blank assay was < 0.001 ng/mL, and a limit of quantification (10% CV) was found at 0.005 ng/mL. The correlation coefficient (r) between hs-cTnT and the conventional assay was 0.997 (p < 0.000). The high-sensitivity assay system could detect cTnT in 88% of samples in which the conventional assay could not detect any immunoreactivity. The 99th percentile in healthy subjects, determined using 559 samples from medical checkups, was 0.011 ng/mL. There was a gender difference (hs-cTnT levels were higher in men than in women), and hs-cTnT levels increased with age. Because hs-cTnT level exceeded 0.011 ng/mL approximately 2 hours after the onset of chest pain in patients with acute myocardial infarction, hs-cTnT can serve as a biomarker for early detection of myocardial infarction. There was a positive correlation (r = 0.491, p < 0.001) between hs-cTnT and NT-proBNP, and hs-cTnT levels increased with the progression of the disease state, as assessed using New York Heart Association (NYHA) classification. These findings indicate that the hs-cTnT assay is sensitive enough to diagnose early-stage acute myocardial infarction and congestive heart failure.

[Recent trends in the clinical characteristics of infective endocarditis: a survey of 54 consecutive cases from 2006 to 2010].

BACKGROUND: It has been reported that the clinical characteristics of infective endocarditis are changing during the course of the decades. However, most of the available data are obtained in the early 2000s or earlier. We therefore evaluated the more recent clinical spectrum of infective endocarditis. METHODS: Fifty-four consecutive patients diagnosed as infective endocarditis based on the Duke criteria at our hospital from January 2006 to December 2010 were evaluated. RESULTS: Of 54 cases, 31 (57%) were male and 23 (43%) were female, with mean age of 57 +/- 17 years. Twenty-three (43%) patients were older than 65 years. The number of patients with diabetes mellitus or undergoing chronic hemodialysis, or cancer were 9 (17%), 5 (9%), and 5 (9%), respectively. In 25 patients (46%), endocarditis occurred without any underlying cardiac disease. The frequencies of streptococcal endocarditis and staphylococcal endocarditis were almost identical [18 (33%) vs. 17 (32%)]. Methicillin resistant staphylococcus aureus was found in 6 patients (11%). CONCLUSIONS: A survey of patients with infective endocarditis from 2006 to 2010 revealed a trend towards increased staphylococcal endocarditis in compromised patients without prior cardiac disorders.

[Antibacterial activity of quinolones against various clinically isolated strains and evaluation of efficacy based on the pharmacokinetics/pharmacodynamics theory].

We compared the antimicrobial activities of oral quinolones, ciprofloxacin (CPFX), gatifloxacin (GFLX), garenoxacin (GRNX), levofloxacin (LVFX), moxifloxacin (MFLX), norfloxacin (NFLX), prulifloxacin (PUFX), and tosufloxacin (TFLX) using Streptococcus pneumoniae, Haemophilus influenzae, Streptococcus agalactiae, Streptococcus pyogenes, extended spectrum beta-lactamase(ESBL) producing Klebsiella pneumoniae, and methicillin-susceptible Staphylococcus aureus (MSSA) isolated from clinical materials. Based on the pharmacokinetics-pharmacodynamics theory, the target attainment rate at the area under the curve (AUC)/MIC of 120 or more for Gram-negative and 30 or more for Gram-positive bacteria was calculated using Monte Carlo simulation (MCS), and was assessed as the efficacy. GRNX showed the lowest MIC50 and MIC90 values (0.03 and 0.06 microg/ml, respectively) against S. pneumoniae, suggesting its potent antimicrobial activity. GRNX also exhibited the most potent antimicrobial activity against Gram-positive bacteria (S. agalactiae, S. pyogenes, MSSA) other than S. pneumoniae. The antimicrobial activity of CPFX against H. influenzae was most potent. The MIC50 and MIC90 values were 0.016 microg/ml each. However, the MIC50 and MIC90 values of the other agents were also favorable. PUFX showed the most potent antimicrobial activity against ESBL-producing K. pneumoniae. Both of MIC50 and MIC90 values were 0.06 and 1 microg/ml, respectively. On efficacy assessment using MCS, GRNX, GFLX, and MFLX showed a probability of 90% or more against S. pneumoniae and S. pyogenes. Against S. agalactiae, GRNX, MFLX, and GFLX showed a probability of approximately 60%. All agents showed a low probability against ESBL-producing K. pneumoniae; PUFX showed a maximum (43.63%). GRNX, MFLX, GFLX, and LVFX showed a probability of 90% or more against MSSA. Furthermore, we investigated the probability that the target value of resistance inhibition, an AUC/MIC of more than 200 against S. pneumoniae, is achieved. GRNX showed the highest probability (95.05%). It also exhibited a similar probability even when the target value was established as 250. Recently, the widespread use of quinolones has increased the number of quinolone-resistant bacteria. In the future, antimicrobial agents should be selected with respect to more potent therapeutic effects and resistance inhibition, and an appropriate dose and administration method must be employed.

Monte Carlo simulation for evaluation of the efficacy of carbapenems and new quinolones against ESBL-producing Escherichia coli.

Extended-spectrum beta-lactamase (ESBL)-producing bacteria are known to be resistant to penicillins, cephalosporins, and monobactams because of their substrate specificity, and these bacteria are sensitive only to a narrow range of antimicrobial agents. The present study was undertaken to evaluate the efficacy of carbapenems and the new quinolones against ESBL-producing Escherichia coli, using a Monte Carlo simulation based on the pharmacokinetic/pharmacodynamic (PK/PD) theory. The time above MIC (TAM, %) served as the PK/PD parameter for carbapenems, with the target level set at 40%. The AUC/MIC served as the PK/PD parameter for the new quinolones, with the target level set at more than 125. In the analysis of drug sensitivity, the MIC50 of all carbapenems other than imipenem was low (0.03 microg/ml), while the MIC50 of the new quinolones was higher (1-2 microg/ml). The probability of achieving the PK/PD target with carba penems after two doses at the usual dose level, as determined by the Monte Carlo simulation, was high for each of the carbapenems tested (99.0% for biapenem, 99.60% for meropenem, and 95.03% for doripenem), except for imipenem. Among the new quinolones, the highest probability of achieving the PK/PD target was obtained with pazufloxacin (42.90%). Thus, the results of the present study have revealed that carbapenems are effective at the regular dose and can be used as the first-choice antibiotics for ESBL-producing E. coli because the resistance ratios for carbapenems are low compared to those of the new quinolones.