Efficiency of riboflavin and ultraviolet light treatment against high levels of biofilm-derived Staphylococcus epidermidis in buffy coat platelet concentrates.

BACKGROUND AND OBJECTIVES: Staphylococcus epidermidis forms surface-attached aggregates (biofilms) in platelet concentrates (PCs), which are linked to missed detection during PC screening. This study was aimed at evaluating the efficacy of riboflavin-UV treatment to inactivate S. epidermidis biofilms in buffy coat (BC) PCs. MATERIALS AND METHODS: Biofilm and non-biofilm cells from S. epidermidis ST-10002 and S. epidermidis AZ-66 were individually inoculated into whole blood (WB) units (~106 colony-forming units (CFU)/ml) (N = 4-5). One spiked and three unspiked WB units were processed to produce a BC-PC pool. Riboflavin was added to the pool which was then split into two bags: one for UV treatment and the second was untreated. Bacterial counts were determined before and after treatment. In vitro PC quality was assessed by flow cytometry and dynamic light scattering. RESULTS: Bacterial counts were reduced during BC-PC production from ~106 CFU/ml in WB to 103 -104 CFU/ml in PCs (P < 0·0001). Riboflavin-UV treatment resulted in significantly higher reduction of S. epidermidis AZ-66 than strain ST-10002 (≥3·5 log reduction and 2·6-2·8 log reduction, respectively, P < 0·0001). Remaining bacteria post-treatment were able to proliferate in PCs. No differences in S. epidermidis inactivation were observed in PCs produced from WB inoculated with biofilm or non-biofilm cells (P > 0·05). Platelet activation was enhanced in PCs produced with WB inoculated with biofilms compared to non-biofilm cells (P < 0·05). CONCLUSION: Riboflavin-UV treatment was similarly efficacious in PCs produced from WB inoculated with S. epidermidis biofilm or non-biofilm cells. Levels of biofilm-derived S. epidermidis ≥103 CFU/ml were not completely inactivated; however, further testing is necessary with lower (real-life) bacterial levels.

Application of the ADVIA cerebrospinal fluid assay to count residual red blood cells in blood components.

BACKGROUND AND OBJECTIVES: There is no automated, accurate assay for the enumeration of residual red blood cells (rRBCs) in non-RBC components for transfusion, despite the potential risk of allo-immunization when mismatched components are transfused. MATERIALS AND METHODS: The automated ADVIA 120 cerebrospinal fluid (CSF) assay, which is approved to count RBCs and WBCs in CSF samples, was optimized and tested to measure rRBC in platelet concentrate (PC) and plasma components. RESULTS: Sample dilution, incubation time and reagent volume were optimized for use with non-RBC blood products. The assay was linear (R(2) = 0·99), even at low rRBCs counts. Intra- and inter-assay variation gave coefficients of variance (CV) between 2·2 and 9·4% and 2·6 and 14·9%, respectively, depending on rRBC levels. Good correlation (r = 0·995) was found between the automated assay and manual counting, which is considered the gold standard. Using the automated assay, the range of rRBCs (count/unit) in buffy-coat platelet concentrate (PCs) was 27-5505 × 10(6) and in apheresis PCs was 1-361 × 10(6). CONCLUSION: The ADVIA CSF assay is a sensitive, precise and accurate means to assess rRBC counts in non-RBC components.

Novel system for storage of buffy-coat-derived platelet concentrates in a glucose-based platelet additive solution: parameters and metabolism during storage and comparison to plasma.

BACKGROUND: In Europe, buffy-coat processing allows for the use of platelet additive solutions (PAS). These solutions, however, have long been questioned for their lack of glucose, a potentially essential nutrient for platelet storage. Using a novel, practical, two-part system for incorporation of glucose into an additive solution (PAS-G), this study compares platelet storage in plasma to storage in PAS-G. STUDY DESIGN AND METHODS: A paired study design of platelet concentrates (PC) were prepared from leucoreduced pools of eight buffy coats (BCP) split into two equal pools, with suspension in autologous plasma, or PAS-G. On days 2, 5, 7 and 9 of storage, samples were tested using standard in vitro platelet parameters. Data were analysed by paired Student's t-tests. RESULTS: During storage, PCs in PAS-G maintain a quality profile that is strikingly similar to PCs stored in plasma in terms of platelet activation (CD62) morphology score, swirl, glucose metabolism and pH. However, PCs in PAS-G perform lower (P < 0.05) in the %ESC and %HSR assays. CONCLUSION: PAS-G's novel presentation allows incorporation of glucose into the additive solution so that it is roughly equivalent to plasma for the maintenance of buffy-coat PCs.

Impact of sample volume and handling time during analysis on the in vitro quality measurements of platelet concentrates held in syringes.

INTRODUCTION: The determination of quality parameters is a necessity for monitoring the efficacy of platelet concentrates. During consolidated quality control studies, there may be a large number of samples to be analyzed at the same time. This common workflow setup triggered the question whether there is an influence of the number of samples to be analyzed on the accuracy of the test results. METHODS: Two different sample volumes of platelet concentrates, 1 ml and 50 ml, were analyzed for a set of standard in vitro parameters including pCO(2), pO(2), pH, glucose, and lactate as well as platelet activation via CD62P expression and responsiveness to adinosine diphosphate in an extent-of-shape-change assay. To assess apoptotic mechanisms triggered by the hold time, changes in the phosphatidylserine exposure were monitored. RESULTS: In total, eleven time points were assessed over a 3-h period as well as an overnight point for assay evaluation. Except for pCO(2) and pO(2), all in vitro parameters analyzed were unaffected by a sample hold time of up to 3-h. CONCLUSION: Sampling for pO(2) determination should be carried out in small volumes and assessed within 30 min of collection to obtain reliable and comparable results.

Physical treatment of Peyronie disease.

OBJECTIVE: Peyronie disease is a localized and progressive fibrosis. It is characterized by a plaque in the tunica albuginea, which leads to penile deformity, making sexual intercourse difficult, if not impossible. DESIGN: During a 4-yr period, we treated 35 patients, aged 30-62 yr, in different stages of this disease. We applied ultrasound therapy (0.5 W/cm; 10 min), infrared radiation, and iontophoresis with 8% potassium iodide (0.2 mA; 30 min). The patients were taught to administer therapy by themselves. The patients' diseases were classified into three stages on the basis of subjective symptoms and clinical findings. At the beginning of treatment, 20 patients' diseases were classified as being in the first stage, 13 patients' diseases in the second stage, and 2 patients' diseases in the third stage. RESULTS: By the end of treatment, 10 patients were cured, 17 patients' diseases were classified as being in the first stage, 8 patients' diseases were in the second stage, and there were no patients in the third stage. CONCLUSIONS: The method is simple, safe, painless, and inexpensive. Patients were taught to administer the therapy by themselves. There were no side effects. Functional improvement and the cessation of pain were noted by all the patients. The level of improvement depended on the disease duration, the length of therapy, and the stage of the disease.