False Prolongation of Prothrombin Time in the Presence of a High Blood Concentration of Daptomycin.

Prothrombin time (PT) can reportedly be falsely prolonged by the antimicrobial drug daptomycin (DAP), and concomitant use of phosphatidylglycerol (PG). Although high doses of DAP (>6 mg/kg/day) are recommended for severe infection and result in a high blood concentration, the extent to which high blood concentrations of DAP interfere with PT, in the presence or absence of PG, has yet to be determined when using the HemosIL RecombiPlasTin 2G (Werfen Japan, Tokyo, Japan). We examined the effects of high doses of DAP on PT using this reagent. DAP (0-500 mg/L) was added to normal plasma and plasma with an already prolonged PT in the presence or absence of liposomal amphotericin B (L-AMB, 5-50 mg/L) or COATSOME EL-01 empty cationic liposomes (CS, 25-250 mg/L). Furthermore, we undertook a Monte Carlo simulation to calculate the probability of achieving DAP concentrations >100, >200 and >500 mg/L 0-48 hr after administering 6-12 mg/kg of DAP. Apparent PT increased with increasing DAP concentration, but neither L-AMB nor CS appeared to further elevate PT when co-administered with DAP. The probability of achieving DAP concentrations >100 and >200 mg/L increased with DAP dose. Higher doses of DAP than the approved dose caused false prolongation of PT. PT should be monitored carefully in patients taking high doses of DAP; ideally, PT should be measured at the trough blood concentration of DAP. Concomitant use of L-AMB and CS did not generally further elevate PT when co-administered with DAP.

An approach for diagnosing plasma cell myeloma by three-color flow cytometry based on kappa/lambda ratios of CD38-gated CD138(+) cells.

BACKGROUND: World Health Organization (WHO) criteria are commonly used to diagnose plasma cell myeloma (PCM); however, these criteria are complex and require several laboratory parameters. For differentiating reactive plasmacytosis from clonal plasma cell (PC) neoplasms such as PCM, it is important to accurately determine the expression of cytoplasmic immunoglobulin light chains. METHODS: We retrospectively analyzed the records of 27 selected patients with PCM who underwent bone biopsies for confirmative diagnosis according to WHO criteria. Twenty-three controls were also investigated. In the present study, all the samples were analyzed using flow cytometry (FC) in the side scatter vs. CD38 histogram mode, and the CD38-gated PC population was identified. Bivariate histograms of CD138/kappa and CD138/lambda were assessed, and the ratios of dual-positive cells to the CD138(+) PC population were calculated. The kappa/lambda ratio was defined as the ratio of CD138/kappa to CD138/lambda. RESULTS: PCM cells were distinguished from normal PCs using cutoff levels between 0.76 and 1.5, at a sensitivity of 96.3% and specificity of 95.7%. CONCLUSIONS: Three-color FC analysis is simple to perform and inexpensive, with clinically relevant data obtained soon after the completion of FC measurements. The detection of the cytoplasmic kappa/lambda ratio of CD38-gated CD138(+) PCs may be a useful tool in the diagnosis of PCM. To the best of our knowledge, this report represents the first diagnostic assessment of the cytoplasmic kappa/lambda ratio in CD38-gated CD138+ PCs using FC analysis. This method may help in more simple, efficient, rapid, and accurate diagnosis of PCM. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1568085959771735.

[Acquisition of accreditation ISO 15189 and view of the future--case of a private college].

We received ISO 15189 accreditation (International Organization for Standardization 15189) in 2009. Several effects from the subjective points are shown below, 1. The reliability of the test results has improved. 2. Skill or knowledge level of staff has improved. 3. Internal recognition has improved. 4. Procedures to prevent accidents have been enforced. 5. Management system has improved. 6. Effective management tool for the manager. In addition to high costs for qualification and maintenance, extensive human resources are required to prepare documents. We need to make further efforts to aim at better cost-effectiveness.

Flow cytometric immunophenotyping of peripheral T cell neoplasms using CD3 gating.

Peripheral T cell neoplasms (PTCNs) such as peripheral T cell lymphoma, adult T cell leukemia/lymphoma, and mycosis fungoides are associated with poorer prognoses compared to B cell neoplasms. Hence, an accurate and early diagnosis is necessary for the successful treatment of PTCNs; however, this can be difficult to achieve. In this study, flow cytometric immunophenotyping using CD3 gating was performed retrospectively on 56 samples from 52 patients diagnosed with PTCNs, and the analytical data were compared with the immunohistochemical findings. Abnormal CD3 T cell populations were distinguishable from the normal T cell population, using this CD3 gating strategy.

[Acquired inhibitor against coagulation factor V with severe hematuria].

A 42-year-old man was admitted with hematuria after a common cold. No purpura could be observed but there was oozing on the site of the forearm where blood had been taken in a previous hospital. Platelet count was 292 x 10(3)/microliter, examination of coagulation system showed abnormalities; prolonged prothrombin time: PT (99.7 sec) and activated partial thromboplastin time: APTT (more than 200 sec), which suggested deficiency of coagulation factor II (FII), factor V (FV) or factor X (FX). In fact, the FV activity was only 2% of the pooled normal plasma. Mixing test of patient's plasma with normal pooled plasma revealed the existence of an FV inhibitor (FVI), which was IgA with an activity levels of 3 Bethesda unit/ml. Although hematuria stopped soon after beginning treatment with steroids (PSL), the abnormalities in PT and APTT improved very slowly and incompletely. At the time of writing, FVI is still observed ten months after onset. The patient had no underlying disease, and in this case FVI appeared following a common cold. Previous reports have said that FVI can cause mild bleeding, and it disappear in a short time. This case showed the possibility of the hidden presence of FVI in patients with hematuria.