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Background: A disposable set for platelet concentrate (PC) preparation by the buffy coat method allows pooling of buffy coats, centrifugation and cell separation with in‐line leucocyte filtration. This study compares three commercially available pooling sets in combination with INTERCEPT pathogen inactivation (PI). Materials and methods: Sets for pooling of buffy coats were from Fresenius Kabi (FRE), Macopharma (MAC) and Terumo BCT (TER). Platelet yield, recovery and concentration were compared before and after PI (n = 20). Platelet quality was assessed by annexin V binding, P‐selectin expression and PAC1 binding. Results: The TER pooling set had the highest platelet yield (5·39 ± 0·44 × 1011) compared with MAC (4·53 ± 0·77) and FRE (4·56 ± 0·51) prior to PI. This was the result of a significantly higher platelet concentration in the TER storage bag (1·41 ± 0·12 × 106/μL) compared with MAC (1·18 ± 0·19) and FRE (1·28 ± 0·15). However, the TER platelet content decreased by 15·6% after PI, yielding 4·55 ± 0·47 × 1011 platelets compared with smaller reductions at 9·5% for MAC (4·10 ± 0·69) and 4·4% for FRE (4·36 ± 0·52). None of the individual PC contained >106 leucocytes. The pH in TER PC was lower compared with MAC and FRE caused by a higher lactic acid production rate. Consequently, PAC1 binding after TRAP activation was lowest for TER PC on day 6. P‐selectin and annexin V were not different between suppliers. Conclusion: This study demonstrates the added value of evaluating the entire component production process when introducing a new consumable. This study helped to inform a decision on what pooling set is ideally suited for routine implementation taking into account PI. [ABSTRACT FROM AUTHOR]

Background Pathogen inactivation methods for platelet concentrates are increasingly being used in blood banks worldwide. In vitro studies have demonstrated its effects on storage lesion, but little routine quality control data on blood banking outcomes have been reported. Materials and Methods Swirling of distributed products was monitored before and after implementation of Intercept pathogen inactivation. Metabolic parameters pH, glucose and lactic acid were determined in a random cohort of expired pathogen-inactivated products. Storage lesion indicators in apheresis concentrates with premature low swirling were compared to concentrates with normal swirling. Results During validation for implementing Intercept pathogen inactivation, pH and glucose levels decreased faster in apheresis platelet concentrates with high platelet content than with low platelet content or than in pathogen-inactivated pooled buffy coat-derived products. In routine products, glucose exhaustion was more often found in apheresis compared to buffy coat-derived platelet concentrates despite 3-7% more plasma carryover in the former. Annual incidence of premature low swirling increased significantly by 50% following implementation of pathogen inactivation implementation for apheresis but not for pooled buffy coat platelet concentrates. In addition, apheresis concentrates with premature low swirling had a significantly higher median platelet count (5·0 × 1011) than unaffected products (3·5 × 1011). Conclusion The risk of increased storage lesion rates following Intercept pathogen inactivation is higher for apheresis than for buffy coat-derived platelet concentrates, especially when platelet contents are higher than 5·0 × 1011. [ABSTRACT FROM AUTHOR]

Background and Objectives Apheresis platelet concentrates sometimes contain persistent aggregates ( PA). Because apheresis involves extracorporeal circulation, we hypothesized that interactions between GPIbα and von Willebrand factor ( VWF) underlie their origin. Materials and Methods Platelets in donations with PA were compared to aggregate-free ( AF) controls. Flow cytometry was used to determine platelet bound VWF. Degranulation was measured using P-selectin expression in flow cytometry and cytokine release using immunosorbent assays. Platelet adhesion to VWF was assessed in hydrodynamic flow and real-time video microscopy. Results Platelets in PA concentrates had significantly more ( P = 0·009, n ≥ 8) bound VWF compared to AF platelets, but differences in VWF concentration, VWF collagen binding, activated VWF or GPIbα expression were not found. Degranulation was higher ( P = 0·030, n = 7) in PA than AF concentrates on day 1 of storage, but adhesion to immobilized VWF under hydrodynamic flow conditions was normal at that moment. On day 6, however, significantly less VWF adhesion ( P = 0·009, n ≥ 6) was found for PA platelets compared to AF, indicating accelerated storage lesion in PA products. In a model that mimicks PA formation by chemically induced binding of VWF to platelets, we found that degranulation, phosphatidylserine expression and metabolism did not differ with paired controls at any time during subsequent storage. Conclusion Accelerated storage lesion is found in concentrates with PA, but this cannot be explained solely by increased platelet bound VWF following apheresis. Therefore, additional stressors are probably responsible for the increases observed in platelet degranulation and storage lesion in products with PA. [ABSTRACT FROM AUTHOR]

Background Aggregates often appear during apheresis. Sometimes, these persist throughout storage, causing product wastage. This study assessed product quality of apheresis concentrates containing persistent aggregates ( PA) and aimed to identify the factors that contribute to their formation. Methods Donation ( n = 180) and platelet indices ( n ≥ 10) from apheresis concentrates with PA were compared with aggregate-free products. Results The proportion of donors with at least one previous PA donation was twofold higher in the PA group ( P < 0·0001) indicating a donor dependence. Significantly higher donor whole blood platelet counts (286 ± 50 vs. 266 ± 49 × 103/μl, P < 0·0001) and higher apheresis yields (6·0 ± 1·6 vs. 5·4 ± 1·5 × 1011, P < 0·0001) were noted in the PA group. Haematocrit was also slightly higher, but age, gender and body mass were similar. The pH of PA products on day six postdonation was significantly lower ( P < 0·001), in line with higher lactic acid concentrations. Flow cytometry showed no differences in GPIbα levels or phosphatidylserine exposure. However, there was slightly more integrin activation as well as increased degranulation measured by P-selectin expression. Cytokine concentrations were also significantly higher in PA concentrates. Aggregation was normal in response to SFLLRN peptide and collagen stimulation, but agglutination at low-dose ristocetin was significantly higher ( P = 0.01) in PA products. Finally, PA were disintegrated by plasmin-mediated thrombolysis but not by integrin αIIbβ3 inhibition. Conclusion Products with PA have acceptable quality parameters, but additional functional studies are warranted. Furthermore, PA are more likely to recur in certain donors who have higher platelet counts. [ABSTRACT FROM AUTHOR]

Background Photochemical treatment ( PCT) of platelet concentrates using photosensitizers and ultraviolet light illumination reduces the proliferation potential of pathogens by damaging biomolecules. Materials and Methods The impact of riboflavin ( RF- PRT)- and amotosalen ( AS- PCT)-based pathogen inactivation on platelets was studied using microfluidic flow chambers on immobilized collagen using standard platelet concentrates prepared from buffy coats in additive solution. Flow cytometry, metabolic parameters and light transmission aggregometry with thrombin-related peptide, collagen and ristocetin were determined concurrently. Results Both PCTs significantly decreased the platelet surface coverage kinetics in flow chambers over the course of the 7-day study. Platelet aggregation was affected following RF- PRT in response to all agonists, while AS- PCT mainly impacted low-dose ristocetin agglutination. RF- PRT induces premature platelet activation because integrin α IIbβ3 was spontaneously activated, and α-degranulation, phosphatidylserine/-ethanolamine exposure and anaerobic metabolism significantly increased following treatment, which was not the case for AS- PCT. On the other hand, AS- PCT significantly diminished thrombus growth onto von Willebrand factor under shear flow. This defect was caused by fewer integrin α IIbβ3 interactions, not by defective GPIbα- VWF binding as shown by adhesion experiments in the presence of tirofiban. Moreover, integrin α IIbβ3 activation was also affected following the activation of platelets via GPVI-Fcγ RIIa or PAR1. Finally, amotosalen illumination as such is sufficient to induce platelet damage, with no additional measurable effect of the chemical adsorption step. Gamma irradiation caused no significant difference compared to controls on any time-point or for any parameter. Conclusion Both PCTs significantly reduce thrombus formation rate but by different biochemical mechanisms. [ABSTRACT FROM AUTHOR]

The article discusses responses to an international forum aimed to gather information on the experiences of blood collection establishments with aggregates in platelet concentrates. Topics include standard procedure to solve the problem of platelet aggregates, the resting period of apheresis, and control of environmental conditions during product handling. Also mentioned are use of plasma or platelet additive solutions (PAS) for storage of platelets and the occurrence of platelet aggregates.

Background and Objective Photochemical pathogen inactivation technologies ( PCT) for individual transfusion products act by inhibition of replication through irreversibly damaging nucleic acids. Concern on the collateral impact of PCT on the blood component's integrity has caused reluctance to introduce this technology in routine practice. This work aims to uncover the mechanism of damage to plasma constituents by riboflavin pathogen reduction technology ( RF- PRT). Methods Activity and antigen of plasma components were determined following RF- PRT in the presence or absence of dissolved molecular oxygen. Results Employing ADAMTS13 as a sentinel molecule in plasma, our data show that its activity and antigen are reduced by 23 ± 8% and 29 ± 9% ( n = 24), respectively, which corroborates with a mean decrease of 25% observed for other coagulation factors. Western blotting of ADAMTS13 shows decreased molecular integrity, with no obvious indication of additional proteolysis nor is riboflavin able to directly inhibit the enzyme. However, physical removal of dissolved oxygen prior to RF- PRT protects ADAMTS13 as well as FVIII and fibrinogen from damage, indicating a direct role for reactive oxygen species. Redox dye measurements indicate that superoxide anions are specifically generated during RF- PRT. Protein carbonyl content as a marker of disseminated irreversible biomolecular damage was significantly increased (3·1 ± 0·8 vs. 1·6 ± 0·5 nmol/mg protein) following RF- PRT, but not in the absence of dissolved molecular oxygen (1·8 ± 0·4 nmol/mg). Conclusions RF- PRT of single plasma units generates reactive oxygen species that adversely affect biomolecular integrity of relevant plasma constituents, a side-effect, which can be bypassed by applying hypoxic conditions during the pathogen inactivation process. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to examine the reliability and validity of the Dyskinesia Impairment Scale (DIS). The DIS consists of two subscales: dystonia and choreoathetosis. It measures both phenomena in dyskinetic cerebral palsy (CP).Method: Twenty-five participants with dyskinetic CP (17 males; eight females; age range 5–22y; mean age 13y 6mo; SD 5y 4mo), recruited from special schools for children with motor disorders, were included. Exclusion criteria were changes in muscle relaxant medication within the previous 3 months, orthopaedic or neurosurgical interventions within the previous year, and spinal fusion. Interrater reliability was verified by two independent raters. For interrater reliability, intraclass correlation coefficients were assessed. Standard error of measurement, the minimal detectable difference, and Cronbach’s alpha for internal consistency were determined. For concurrent validity of the DIS dystonia subscale, the Barry–Albright Dystonia Scale was administered.Results: The intraclass correlation coefficient for the total DIS score and the two subscales ranged between 0.91 and 0.98 for interrater reliability. The reliability of the choreoathetosis subscale was found to be higher than that of the dystonia subscale. The standard error of the measurement and minimal detectable difference values were adequate. Cronbach’s alpha values ranged from 0.89 to 0.93. Pearson’s correlation between the dystonia subscale and Barry–Albright Dystonia Scale was 0.84 (p<0.001).Interpretation: Good to excellent reliability and validity were found for the DIS. The DIS may be promising for increasing insights into the natural history of dyskinetic CP and evaluating interventions. Future research on the responsiveness of the DIS is warranted. [ABSTRACT FROM AUTHOR]

Aim This study investigated the reliability and validity of the Barry–Albright Dystonia Scale (BADS), the Burke–Fahn–Marsden Movement Scale (BFMMS), and the Unified Dystonia Rating Scale (UDRS) in patients with bilateral dystonic cerebral palsy (CP). Method Three raters independently scored videotapes of 10 patients (five males, five females; mean age 13y 3mo, SD 5y 2mo, range 5–22y). One patient each was classified at levels I–IV in the Gross Motor Function Classification System and six patients were classified at level V. Reliability was measured by (1) intraclass correlation coefficient (ICC) for interrater reliability, (2) standard error of measurement (SEM) and smallest detectable difference (SDD), and (3) Cronbach’s alpha for internal consistency. Validity was assessed by Pearson’s correlations among the three scales used and by content analysis. Results Moderate to good interrater reliability was found for total scores of the three scales (ICC: BADS=0.87; BFMMS=0.86; UDRS=0.79). However, many subitems showed low reliability, in particular for the UDRS. SEM and SDD were respectively 6.36% and 17.72% for the BADS, 9.88% and 27.39% for the BFMMS, and 8.89% and 24.63% for the UDRS. High internal consistency was found. Pearson’s correlations were high. Content validity showed insufficient accordance with the new CP definition and classification. Interpretation Our results support the internal consistency and concurrent validity of the scales; however, taking into consideration the limitations in reliability, including the large SDD values and the content validity, further research on methods of assessment of dystonia is warranted. [ABSTRACT FROM AUTHOR]

Platelet apheresis sometimes causes persistent aggregates ( PA). This study ( n = 211) shows that changing the apheresis settings to reach fixed product volumes instead of yields does not influence PA incidence, even though PA products on average contain more platelets than controls. Furthermore, logistic regression was used to model if PA can be predicted on the basis of certain predonation parameters. PA donation history was the only parameter retained, proving a strong determinant of predictability [ AUC = 0.735 ( SE = 0.022)]. Consequently, donations from a donor with previous PA history are 7.8 times more likely to contain PA than from a donor without preceding history. [ABSTRACT FROM AUTHOR]

This study investigated interrater reliability and measurement error of the Melbourne Assessment of Unilateral Upper Limb Function (Melbourne Assessment) and the Quality of Upper Extremity Skills Test (QUEST), and assessed the relationship between both scales in 21 children (15 females, six males; mean age 6y 4mo [SD 1y 3mo], range 5–8y) with hemiplegic CP. Two raters scored the videotapes of the assessments independently in a randomized order. According to the House Classification, three participants were classified as level 1, one participant as level 3, eight as level 4, three as level 5, one participant as level 6, and five as level 7. The Melbourne Assessment and the QUEST showed high interrater reliability (intraclass correlation 0.97 for Melbourne Assessment; 0.96 for QUEST total score; 0.96 for QUEST hemiplegic side). The standard error of measurement and the smallest detectable difference was 3.2% and 8.9% for the Melbourne Assessment and 5.0% and 13.8% for the QUEST score on the hemiplegic side. Correlation analysis indicated that different dimensions of upper limb function are addressed in both scales. [ABSTRACT FROM AUTHOR]

Objective To investigate the initial efficacy and predictive factors of full-spectrum therapy in the treatment of children and young adolescents with nocturnal enuresis (NE). Patients and methods Combined therapy for NE comprises an enuresis alarm, bladder training, motivational therapy and pelvic floor muscle training, and is more effective than each of the components alone or than medical intervention. A total of 60 children and adolescents (aged 4–20 years) with NE were treated once a week with full-spectrum therapy for a maximum of 6 months. Results Overall the therapy was successful (14 consecutive dry nights) in 52 of 60 patients. At 30 days the cure rate was 33%, after 60 days 72% and after 98 days, 87%. The remaining 13% did not achieve 14 consecutive dry nights; seven patients improved, having fewer dry nights/week. One patient discontinued the treatment because of lack of motivation. In children with an initial maximum bladder capacity less than normal for age, the capacity increased from 53% of the normal maximum bladder capacity in week 1 to 88% at the end of treatment. Neither age, gender, sleep arousal, bladder capacity, family history and pathophysiological profile had any association with the success rate. Conclusion The short-term success rate of full-spectrum therapy for NE is high. Age, gender, sleep arousal, bladder capacity, family history and pathophysiological profile of enuresis are unrelated to the success of the intervention. [ABSTRACT FROM AUTHOR]

Objectives: The aims of this study were to assess whether the site of lesion is predictive of upper limb recovery after stroke and to determine whether this information adds to the predictive ability of the clinical examination., Material and Methods: Forty-five patients were examined at entry to the study and at 2 and 12 months after stroke. The Brunnström-Fugl-Meyer test was used as outcome measurement. Predictor variables included clinical parameters and classifications of lesion site (obtained by CT/MRI)., Results: Correlation analysis revealed small to moderate relationships between lesions of subcortical structures and arm outcome at 2 months. In multiple regression analysis, the best model for predicting recovery at 2 months was found to be a combination of the clinical parameters with a purely subcortical lesion. Motor recovery at 12 months was best predicted by the clinical tests alone. The results further indicated that patients with subcortical damage tended to take longer to recover., Conclusions: Clinical assessment is most useful for determination of the prognosis of upper limb recovery after stroke. Neuroanatomical parameters measured by CT or MRI can only act as an adjunct.