Reversibility of platelet P2Y12 inhibition by platelet supplementation: ex vivo and in vitro comparisons of prasugrel, clopidogrel and ticagrelor

Essentials Successful outcome of platelet transfusion depends on specific antiplatelet therapy in use. We assessed if ticagrelor, clopidogrel or prasugrel impacts on donor platelet activity ex vivo. Ticagrelor and/or its active metabolite in plasma or bound to platelets can inhibit donor platelets. This might compromise the effectiveness of platelet transfusion therapy.

SUMMARY

Background Platelet transfusion is the conventional approach to restore platelet function during acute bleeds or surgery, but successful outcome depends on the specific antiplatelet therapy. Notably ticagrelor is associated with inadequate recovery of platelet function after platelet transfusion. We examined whether plasma and/or platelets from ticagrelor-treated patients influence donor platelet function, in comparison with clopidogrel and prasugrel. Methods Platelet transfusion was mimicked ex vivo by mixing naïve donor platelet-rich plasma (PRP) or gel-filtered platelets (GFP) in defined proportions with PRP, plasma or GFP from cardiovascular patients receiving standard care including medication with prasugrel, clopidogrel or ticagrelor (n = 20 each). Blood was taken 4 h after the previous dose. HLA2/HLA28 haplotyping let us distinguish net (all platelet) and individual patient/donor platelet reactivity in mixtures of patient/donor platelets, measured by flow cytometry analysis of ADP-induced fibrinogen binding and CD62P expression. Results ADP responsiveness of donor platelets was dramatically reduced by even low (10%) concentrations of PRP or plasma from ticagrelor-treated patients. Clopidogrel and prasugrel were associated with more modest donor platelet inhibition. GFP from ticagrelor-treated patients but not patients receiving clopidogrel or prasugrel also suppressed donor GFP function upon mixing, suggesting the transfer of ticagrelor from patient platelets to donor platelets. This transfer did not lead to recovery of ADP responsiveness of patient's platelets. Conclusion Collectively, these observations support the concept that ticagrelor and/or its active metabolite in plasma or bound to platelets can inhibit donor platelets, which might compromise the effectiveness of platelet transfusion therapy.

Rhesus CE expression on patient red blood cells is an independent prognostic factor for adenocarcinoma of the lung

OBJECTIVES

The influence of blood group antigens on cancerogenesis is shown for distinct tumor types, yet the impact of Rhesus blood group antigens in lung cancer is not clarified.

MATERIALS AND METHODS

To investigate the impact of Rhesus blood groups a non-small cell lung cancer (NSCLC) collective (n = 1047) was analyzed retrospectively. Using a second cohort of n = 340 primarily operated stage I-III NSCLC patients, we evaluated immunohistochemistry of CD47-antibody stained tissue samples in correlation to histopathologic subtype and Rhesus blood group.

RESULTS AND CONCLUSION

In 516 of 1047 patients blood group data were available. Seven different RhCE phenotypes were grouped as "··ee," "ccE·," and "C·E·." Adenocarcinoma patients with Rh "··ee" revealed improved overall survival (29 (21.2-36.8) m; HR 1.00 [index]) compared with Rh "ccE·" (19 (1.9-36.1) m; HR 1.76 [1.15-2.70]) and Rh "C·E·" (10 (7.4-12.6) m; HR 2.65 [1.70-4.12]) univariately (P < .001) and multivariately (P < .001). Rh "··ee" showed reduced incidence of CNS-metastasis (P = .014) and metastasis count (P = .032) in stage IV adenocarcinoma. Immunohistochemistry associated CD47-positivity with adenocarcinomas (n = 340, P = .048). In n = 51 cases blood group data were available. The prognostic effect of Rh "··ee" compared with Rh "ccE·" and Rh "C·E·" was stated (P = .001), foremost in CD47-positive adenocarcinomas (Rh "··ee" vs. Rh "ccE·" and Rh "C·E·," P = .008). Inversely Rh "ccE·" or Rh "C·E·" was found beneficial in CD47-negative non-adenocarcinomas (P = .046). Phenotypic RhCE expression may be an independent prognostic factor for overall survival in adeno-NSCLC. We hypothesize an erythrocytic-immunologic interaction with tumor tissue, possibly altered by RhCE and CD47, resulting in a metastatic prone condition.

IL10 promoter polymorphisms are associated with systemic onset juvenile idiopathic arthritis (SoJIA)

OBJECTIVES

Juvenile idiopathic arthritis (JIA) is a rare, but severe cause of childhood disability. Systemic onset JIA (SoJIA) accounts for approximately 5.8% of all JIA cases and is associated with cytokine dysregulation, including interleukin (IL-)1, IL-6 and tumour necrosis factor (TNF-)α. IL-10 is an immuno-regulatory cytokine, which in part regulates inflammation by controlling inflammatory cytokine expression. Dysregulation in IL-10 expression and certain single nucleotide polymorphisms (SNPs) in the IL-10 promoter were shown to be associated with autoimmune and infectious diseases.

METHODS

Genomic DNA-samples from SoJIA patients from two German Paediatric Rheumatology centres, and healthy controls were analysed for three well defined IL-10 promoter SNPs (-1082G>A, -819C>T, and -592C>A). These SNPs are in tight linkage disequilibrium, and result in three predominant (or 'classical') haplotypes: ATA, ACC, and GCC. ATA and ACC are associated with low and medium, GCC is associated with high IL-10 expression.

RESULTS

Here, we show a strong association of IL-10 promoter polymorphisms with SoJIA. We demonstrate a significantly increased frequency of low IL-10 expressing -1082A/A alleles, the medium IL-10 expressing ACC haplotype (p=0.01), and an enrichment of the rare GTC haplotype (p<0.001) in patients with SoJIA. Heterozygous -1082G/A alleles (p<0.001), and the GCC haplotype (p<0.001) on one allele protect from developing SoJIA.

CONCLUSIONS

This suggests a central role of the immuno-regulatory cytokine IL-10 in the pathogenesis of SoJIA.

Blood chimerism in a girl with Down syndrome and possible freemartin effect leading to aplasia of the Müllerian derivatives

Cytogenetic and molecular genetic analysis in a case of sex-discordant dizygotic twins revealed blood chimerism in the girl (46,XY in blood and 47,XX, + 21 in fibroblasts) caused by feto-fetal transfusion from her healthy brother. The girl presented with Down syndrome, aplasia of the uterus and the Fallopian tubes and normal female external genitalia. We propose that the lack of Müllerian structures is caused by the effect of the Müllerian inhibiting substance transferred from the male to the female twin in early pregnancy. This disorder of sex development is known as freemartin phenomenon in female cattle from sex-discordant twin pairs.

Increased expression of the adult stem cell marker Musashi-1 in endometriosis and endometrial carcinoma

Adult stem cells are thought to be responsible for the high regenerative capacity of the human endometrium, and have been implicated in the pathology of endometriosis and endometrial carcinoma. The RNA-binding protein Musashi-1 is associated with maintenance and asymmetric cell division of neural and epithelial progenitor cells. We investigated expression and localization of Musashi-1 in endometrial, endometriotic and endometrial carcinoma tissue specimens of 46 patients. qPCR revealed significantly increased Musashi-1 mRNA expression in the endometrium compared to the myometrium. Musashi-1 protein expression presented as nuclear or cytoplasmic immunohistochemical staining of single cells in endometrial glands, and of single cells and cell groups in the endometrial stroma. Immunofluorescence microscopy revealed colocalization of Musashi-1 with its molecular target Notch-1 and telomerase. In proliferative endometrium, the proportion of Musashi-1-positive cells in the basalis layer was significantly increased 1.5-fold in the stroma, and three-fold in endometrial glands compared to the functionalis. The number of Musashi-1 expressing cell groups was significantly increased (four-fold) in proliferative compared to secretory endometrium. Musashi-1 expressing stromal cell and cell group numbers were significantly increased (five-fold) in both endometriotic and endometrial carcinoma tissue compared to secretory endometrium. A weak to moderate, diffuse cytoplasmic glandular staining was observed in 50% of the endometriosis cases and in 75% of the endometrioid carcinomas compared to complete absence in normal endometrial samples. Our results emphasize the role of Musashi-1-expressing endometrial progenitor cells in proliferating endometrium, endometriosis and endometrioid uterine carcinoma, and support the concept of a stem cell origin of endometriosis and endometrial carcinoma.

Identification of the novel allele HLA-A*9237 in peripheral blood of a bone marrow donor

The new HLA-A*9237 differs from HLA-A*020601 by one nonsynonymous nucleotide exchange at codon 127 (AAA to AAC).

Evidence for susceptibility determinant(s) to psoriasis vulgaris in or near PTPN22 in German patients

INTRODUCTION

Variant R620W of protein tyrosine phosphatase non-receptor type 22 (PTPN22) has consistently been reported as a susceptibility factor for several autoimmune diseases. We investigated its role in susceptibility to psoriasis, the relevance of possibly other disease-causing variants, and interdependency of the major risk factor for psoriasis at PSORS1.

METHODS

R620W was tested in a case-control study initially with 375 German patients and then with an enlarged sample of an additional 418 patients. Analyses were extended to linkage disequilibrium (LD) based haplotypes. Potential interaction between risk haplotypes of PTPN22 and the PSORS1 associated risk allele was tested by regression analysis. PTPN22 coding sequence was determined in 20 patients carrying the risk haplotype. Association and regression analysis were also performed in the extended case-control study.

RESULTS

R620W was not associated in either case-control study, while significant association (corrected for multiple testing) with one haplotype (C-4) of the LD block encompassing PTPN22 as well with another haplotype (B-3) within an adjacent telomeric LD block was detected. No evidence for interaction between risk haplotype C-4 and the PSORS1 associated risk allele was found. Sequencing excluded other coding variants within PTPN22 as a basis for association findings. Analysis of the extended study group confirmed association for haplotypes B-3 and C-4 and independence of risk haplotypes C-4 and PSORS1.

DISCUSSION

We exclude a major role of *620W in German psoriasis patients but suggest that other susceptibility determinant(s) within non-coding regions of PTPN22 or its proximity might exist acting independently of the major PSORS1 risk factor.

Lack of genetic association of the three more common polymorphisms of CARD15 with psoriatic arthritis and psoriasis in a German cohort

OBJECTIVE

To determine whether the three common independent sequence variants of the putative pleiotropic non-MHC autoimmune gene CARD15 influence disease susceptibility in large German cohorts of patients with psoriatic arthritis and psoriasis vulgaris, before and after stratification to HLA-C.

METHODS

DNA was obtained from 375 patients with psoriatic arthritis, 281 patients with psoriasis vulgaris without joint involvement, and 376 controls. The three variants of the CARD15 gene (R702W, G908R, leu1007fsinsC), and two single nucleotide polymorphisms of the HCR gene (HCR-325, HCR-2327) for HLA-C stratification were genotyped using allelic discrimination Taqman assays.

RESULTS

No significant differences in genotype frequencies were observed between controls and either the psoriatic arthritis or the psoriasis vulgaris patient population, even after stratification to HLA-C in both patient cohorts, or to the type of joint involvement within the psoriatic arthritis group.

CONCLUSIONS

The lack of genetic association between the most common Crohn's disease alleles of the CARD15 gene and psoriatic joint disease on large cohorts of white patients does not support a recently claimed role for CARD15 as the first non-MHC susceptibility gene in the pathogenesis of psoriatic arthritis, but confirms and extends previous studies in the case of psoriasis vulgaris.

Platelet glycoprotein complex Ia/IIa antibodies cause neonatal alloimmune thrombocytopenia but do not inhibit megakaryopoiesis and platelet recovery after allogeneic cord blood stem cell transplantation

A sibling cord blood (CB) transplantation was performed in a boy with Wiskott-Aldrich syndrome. The CB (31 x 10(6) CD34(+) cells) derived from a newborn sister with neonatal alloimmune thrombocytopenia (NAIT) with 40,000 platelets/microl, caused by a maternal anti-HPA-5b and HLA-A2 antibody. Maternal serum did not inhibit clonogenicity after in vitro testing of megakaryopoiesis. Accordingly, this CB was accepted for sibling transplantation. The transplantation showed a good course with fast and sustained hematopoietic reconstitution (granulocytes >500/microl on day +16, platelets >50,000/microl on day +30). This case demonstrates a successful CB transplantation from a donor suffering from NAIT.

A curriculum for training patients with peripheral visual field loss to use bioptic amorphic lenses

This article describes the experimental protocol used to instruct fifteen patients with peripheral visual field loss due to retinitis pigmentosa, choroideremia, or Usher's syndrome Type II how to effectively use bioptic amorphic lenses. The factors that contributed to the successful use of these lenses, as well as difficulties the patients encountered, are discussed. The results of the study (published in detail in Szlyk et al. Use of bioptic amorphic lenses to expand the visual field in patients with peripheral loss. Optom Vis Sci 1998;75:518-24) indicate that bioptic amorphic lenses, when combined with a comprehensive training program, can expand visual function in the areas of peripheral detection, recognition, scanning, tracking, visual memory, and mobility.

Measuring the effectiveness of bioptic telescopes for persons with central vision loss

PURPOSE

1) To evaluate a vision rehabilitation program aimed at training persons with central vision loss to use a bioptic telescope for improving life skills, including driving and 2) to compare the outcomes of subjects who are given bioptic telescopes and training, with subjects who are prescribed telescopic lenses without training.

METHODS

Twenty-five subjects ranging in age from 16 to 78 years were included in the study. Each subject was randomized to one of three groups: Group 1 received bioptic telescopes and training during the first approximately 3-month-long period of the approximately 6-month-long study; Group 2 received lenses and training during the second approximately 3-month-long period of the study; and Group 3 received the lenses for approximately 3 months without any training. An assessment battery consisting of clinical vision tests, functional tasks evaluated by an orientation and mobility specialist, driving skills evaluated by a kinesiotherapist specializing in driver's education, and psychophysical measures was administered to Groups 1 and 2 at baseline, and at approximately 3 and 6 months, and to Group 3 at baseline and at approximately 3 months. The tasks were categorized into 6 major functional categories: Recognition, Mobility, Peripheral Identification, Scanning, Tracking, and Visual Memory. Training consisted of 5 weeks of laboratory-based training focusing on skills within these 6 categories, and 8 weeks of on-road driving training.

RESULTS

There was significant improvement in all task categories with use of the telescopes. There was improvement in all task groups with training, though a significant difference between the trained and untrained groups existed only in the Recognition, Peripheral Identification, and Scanning Categories, but not in Mobility, Tracking, or Visual Memory. When the tasks involving driving-related skills were analyzed separately, training also had a significant effect.

CONCLUSION

There was significant improvement in visual skills with the use of a bioptic telescope. This improvement was greater with training in the use of the lenses in a number of visual skills categories including driving-related skills.

Use of bioptic amorphic lenses to expand the visual field in patients with peripheral loss

PURPOSE

To test the effectiveness of a bioptic form of a peripheral vision-enhancement lens in patients with retinitis pigmentosa (RP), choroideremia, and Usher's syndrome Type II.

METHODS

Fifteen patients with peripheral visual field loss were trained in the use of the amorphic lenses for driving and other everyday activities for a 3-month period. A cross-over study design was used, where one group of eight patients received training during the first 3 months of the 6-month study, and another group of seven patients received training during the second 3 months. All patients were administered a battery of clinical, psychophysical, functional, mobility, and driving assessment tests at the beginning of the study, at 3 months, and at 6 months. The assessment tests were coded according to the primary visual skill involved in the task. These visual skills included: recognition, peripheral detection, scanning, tracking, visual memory, and mobility.

RESULTS

After training, the patients showed improvement in all visual skills categories on the assessment tests, with overall improvement of 37%. There was no significant difference in the levels of improvement between the two groups. Those with smaller visual field extents showed significantly greater improvement on peripheral detection and scanning tasks. Those patients trained during the first 3 months of the study maintained their skills when tested at the 6-month point.

CONCLUSION

Patients with peripheral vision loss may benefit from a rehabilitation program which combines low vision training with amorphic lenses in a bioptic configuration.

The influence of different erythrocyte lysing procedures on flow cytometric determination of CD34+ cells in umbilical cord blood transplants

Since the correct determination of CD34+ cells is of great clinical importance for successful transplantation with haematopoietic progenitor cells (HPCs) from cord blood, we investigated the influence of different erythrocyte lysing techniques on the quantification of CD34+ cells in umbilical cord blood. Flow cytometric determinations of CD34+ cells were performed from 20 cord blood samples, using three different erythrocyte lysing procedures and two monoclonal CD34 antibodies (n = 360). Flow cytometric analysis showed characteristic patterns of the forward (FSC) and side (SSC) scatter light properties for the leucocyte subsets for each of the investigated erythrocyte lysing procedures, indicating that these reagents cause different morphological changes on leucocytes. Furthermore, significant differences of CD34+ cell counts were obtained for identical samples using different lysing techniques (P = 0.001 and P = 0.002). In some cases, a more than 100% difference was found comparing different erythrocyte lysing procedures. In contrast, the determination of CD34+ cells by two CD34 antibodies showed a good reproducibility without significant differences between both antibodies for each of the erythrocyte lysing techniques. We conclude that the erythrocyte lysing procedure represents a very critical and important step for accurate determination of CD34+ cells in whole blood samples. Especially for the quantification of HPCs in cord blood transplants, this influence may be of high clinical relevance.

Suppression of panel-reactive antibodies by treatment with mycophenolate mofetil

"Panel Reactive Antibody" (PRA) testing is commonly used to assess the pretransplant antibody status in order to estimate the risk of an adverse humoral response following transplantation. We report on a female patient with end-stage cardiac failure suffering from acute myocarditis who underwent implantation of a left-ventricular assist device (Novacor, Baxter Healthcare Corp. Oakland, CA). During evaluation for heart transplantation, a PRA level of 50-70% was detected. After treatment with mycophenolate mofetil at a dosage of 2 g daily, PRA levels declined within one week to 0-5%, and remained low after discontinuation of the immunosuppressive drug. We feel that pretreatment of patients with elevated PRA levels with mycophenolate mofetil is well justified.

Efficacy and kinetics of bone marrow processing and enrichment of haematopoietic progenitor cells (HPC) by a large-volume apheresis procedure

We investigated the efficacy of bone marrow (BM) processing by an automated large-volume apheresis procedure (6 x original BM volume) in 10 paediatric and adult patients undergoing BM harvesting before myeloablative therapy. Volume-dependent kinetics during apheresis were analyzed by sequential collection of processed cells into a six-fold collection bag system with consecutive analysis of the single bags. BM processing resulted in an 83.3% (+/- 21) recovery of mononuclear cells (MNC), a 97.9% (+/- 1.1) reduction of erythrocytes (RBC) and a 87.7% (+/- 2.9) volume reduction. To determine volume-dependent kinetics of haematopoietic progenitor cell (HPC) enrichment during apheresis, leukocytes (WBC), mononuclear cells (MNC), CD34 cells and colony-forming cells (CFU-GM) were serially quantitated in subsequent collection bags. Large-volume BM processing significantly enhanced absolute yields of CD34+ cells (mean: 4.01 (+/- 2.81) x 10(6)/kg bw) and CFU-GM (mean: 1.92 (+/- 1.47) x 10(4)/kg bw) compared with the standard procedure (3 x BM volume) by 26.9% (+/- 10.9) and 27.2% (+/- 11.6), respectively. We concluded that large-volume apheresis for BM processing is an efficient technique significantly improving the yields of haematopoietic progenitor cells (HPC) without any relevant changes in the purity of the final product. Moreover, sequential collection and analysis of HPC represents a good model to investigate the volume-dependent kinetics and efficacy of BM processing.

A comparison of driving in older subjects with and without age-related macular degeneration

OBJECTIVE

To determine the effects of age and central vision loss on driving skills.

METHODS

Ten subjects with age-related macular degeneration and average binocular visual acuity of 20/70, and 11 age-similar subjects with normal vision, were examined with a battery of cognitive and visual tests, an interactive driving simulator, and an on-road driving test. Data were collected on the frequency of real-world accidents and convictions for traffic violations.

RESULTS

There were no significant differences between the two groups on any of the cognitive tests. The age-related macular degeneration group demonstrated poorer performance on the driving simulator, including delayed braking response times to stop signs, slower speeds, and more of both lane boundary crossings and simulator accidents. The age-related macular degeneration group also demonstrated poorer overall on-road test performance, including having significantly more points deducted for driving too slowly and for not maintaining proper lane position. However, these effects on the simulator and the on-road test did not translate into an increased risk of real-world accidents for the age-related macular degeneration group. Significantly more control subjects than patients with age-related macular degeneration were involved in self-reported accidents, and significantly more control subjects had state convictions for traffic violations. There was evidence of compensation in the age-related macular degeneration group in four major areas: (1) not driving in unfamiliar areas; (2) traveling at slow speeds; (3) self-restricting their nighttime driving, and (4) taking fewer risks while driving (eg, not changing lanes). There was also evidence of compensation in the older control group.

CONCLUSIONS

Vision, simulator, and on-road test variables combined with subjective risk taking predicted self-reported real-world accidents in a logistic regression analysis. However, risk taking, rather than simulator or road-test performance, was the most significant predictor for both patients with age-related macular degeneration and the control group.

Apparently changing patterns of inheritance in Alport's hereditary nephritis: genetic heterogeneity versus altered diagnostic criteria

With the use of more stringent diagnostic criteria, it has recently been shown that some large pedigrees of Alport's and non-Alport's hereditary nephritis fit sex-linked dominant inheritance (O'Neill et al. 1978). We have used similar diagnostic criteria and have studied a number of Michigan pedigrees in order to see if this hypothesis would be confirmed. We found one small pedigree which definitely shows male-to-male transmission, while one large pedigree is tentatively compatible with sex-linked dominant inheritance. Many of the other pedigrees suggested male-to-male transmission. This Michigan experience is compared to other published reports and found to be consistent, although a trend of fewer reports of male-to-male transmission is seen. We conclude that genetic heterogeneity of Alport's hereditary nephritis is likely.