Rapid detection of bacterial contamination of platelet-rich plasma-derived platelet concentrates using flow cytometry.

Flow cytometry can be used to detect bacterial contamination of platelet products. In this study, we investigated whether the incubation of a minimal volume of platelet-rich plasma (PRP)-derived platelet concentrates (PCs) with growth medium improved the analytical sensitivity of flow cytometry. Five bacterial strains (Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Klebsiella pneumoniae, and Escherichia coli) were used. Platelets were inoculated with 10, 10(2), and 10(3) CFUs per mL; 0.5 mL, 1.0 mL, and 2.0 mL aliquots of spiked platelets were incubated with growth medium at 37°C for 24 hours. During the incubation period, the numbers of events were analyzed every 4 hours by flow cytometry. We could detect a low concentration (10 CFUs per mL) of bacteria in a small volume (minimum 0.5 mL) of PCs. Irrespective of spiking concentrations and incubation volumes, the detection times of S. aureus and S. epidermidis were 24 hours or less, while those of B. cereus, K. pneumoniae, and E. coli were 16 hours or less. A higher spiking concentration made it possible to shorten the detection time. The numbers of detected bacteria increased during the incubation. However, the graphs corresponding to K. pneumoniae and E. coli showed peak levels and decreasing patterns during the incubation period. The incubation of small volumes of PC with growth medium increased the analytical sensitivity of flow cytometry for bacterial detection. Therefore, flow cytometry can serve as a useful method for sterility testing using PRP-derived PCs with only low levels of consequent platelet loss.

Molecular cytogenetic analysis of Korean patients with Waldenström macroglobulinemia.

To compare the molecular cytogenetic characteristics between Waldenström macroglobulinemia (WM) and multiple myeloma (MM), we performed interphase fluorescent in situ hybridization (FISH) in Korean patients with WM and MM. Forty patients with WM and 132 patients with MM were enrolled onto the study. FISH was performed with seven different probes: 6q21, 6q23, CEP4, CEP9, immunoglobulin (IgH) breakapart, RB1 gene, and 1q25. Out of 22 WM patients, 4 (18%) had abnormal karyotypes, mainly structural changes on conventional karyotyping. After performing FISH for the available 29 cases, deletions of 6q23 and 6q21 were newly detected in 3 cases (10%). There was no other anomaly, including trisomy 4 in WM. No 6q deletion was observed in MM patients, but RB1 deletion was the most common change (45%), followed by IgH translocation (42%) and gain of 1q (38%). In conclusion, Korean WM patients had a low rate of 6q deletion (10%) and no trisomy 4.

Prognostic values of the factor Xa-activated clotting time and endogenous thrombin potential in patients suspected of having disseminated intravascular coagulation.

BACKGROUND: Widespread coagulation activation and intravascular fibrin formation are clinical features of disseminated intravascular coagulation (DIC). The endogenous thrombin potential (ETP) has been shown to be a useful marker for hypo- or hypercoagulability. The factor Xa-activated clotting time (XACT) represents plasma levels of procoagulant phospholipids. We investigated whether the ETP and XACT would be good prognostic markers in patients suspected of having DIC and whether these markers would show a significant correlation with the thrombin-antithrombin complex (TAT), a marker of in vivo coagulation activation. METHODS: One hundred twenty-nine patients suspected of having DIC were enrolled for the study. The TAT was measured by ELISA. The ETP and XACT were measured by calibrated automated thrombinography. The 28-day mortality was used as a predictor of clinical outcomes. RESULTS: In overt DIC, higher XACT (9.67 vs. 7.33 min) and higher TAT (26.15 vs. 11.56 ng/ml) results were obtained from the nonsurvivors than from the survivors. ETP levels were lower in the overt DIC group than in the no overt DIC group. In receiver operating characteristic analysis, which was conducted to predict the 28-day mortality, the areas under the receiver operating characteristic analysis curve were as follows: 0.71 (95% CI: 0.62-0.78) for the XACT, 0.70 (0.61-0.77) for the TAT, and 0.64 (0.55-0.72) for the ETP. For the diagnosis of overt DIC, the area under the curve of XACT, TAT and ETP were 0.77 (0.69-0.84), 0.64 (0.55-0.72) and 0.73 (0.64-0.80), respectively. The odds ratio of the XACT for the relative risk of 28-day mortality was 9.60 (3.53-26.11), and that of the TAT was 5.18 (2.11-12.72) and that of the ETP 7.66 (1.67-35.17). For the diagnosis of overt DIC, the odds ratio of XACT, TAT and ETP were 37.35 (4.86-286.89), 4.89 (1.93-12.43) and 4.89 (1.98-12.09), respectively. There was a negative correlation between the TAT and ETP (r=-0.223, P=0.012) and a positive correlation between the TAT and XACT (r=0.251, P=0.004). CONCLUSION: Our results suggest that the XACT and ETP may be useful diagnostic and prognostic markers for the DIC. Among various markers, the XACT serves as a good prediction of the 28-day mortality in patients suspected of having DIC.

[Clinical usefulness of plasma interleukin-6 and interleukin-10 in disseminated intravascular coagulation].

BACKGROUND: Disseminated intravascular coagulation (DIC) is a syndrome characterized by a systemic activation of coagulation leading to the intravascular deposition of fibrin and the simultaneous consumption of coagulation factors and platelets. Inflammatory cytokines can activate the coagulation system. This study investigated the diagnostic and prognostic usefulness of the plasma level of interleukin-6 (IL-6) and interleukin-10 (IL-10) for predicting DIC. METHODS: The study populations were 15 healthy controls and 81 patients who were clinically suspected of having DIC and were requested to perform DIC battery tests. The presence of overt DIC was defined by the International Society on Thrombosis and Haemostasis Subcommittee cumulative score of 5 or above. The 28 day mortality was used to assess the prognostic outcome. The plasma levels of the cytokines were measured by ELISA. RESULTS: The plasma levels of IL-6 and IL-10 in patients (N=81) were higher than those of control (N=15). IL-6 and IL-10 levels of overt DIC group (N=31) were 3 times and 1.5 times higher than those, respectively, of non-overt DIC group (N=50). In infection group (N=48), IL-6 and IL-10 levels of overt DIC group (N=18) were 5 times and 3 times higher than those, respectively, of non-overt DIC group (N=30). The diagnostic efficiency of IL-6 (optimal cut off >40.4 pg/mL) and IL-10 (>9.7 pg/mL) for the diagnosis of overt DIC were 67% and 69%, respectively, which were similar to that of D-dimer. Plasma levels of IL-6 and IL-10 were also higher in non-survivors than in survivors. The patients with higher levels of IL-6 and IL-10 showed a poorer prognosis. CONCLUSIONS: The proinflammatory cytokine, IL-6 and anti-inflammatory cytokine, IL-10 were useful for the diagnosis of overt DIC and the prediction of its prognosis. These results also showed the evidence of a close interaction between coagulation and inflammation.