Proportion Of Donor Research Articles

Noninvasive prenatal screening in a pregnant woman with a history of stem cell transplant from a male donor: A case report and literature review.

As a screening method, inaccuracies in noninvasive prenatal screening (NIPS) exist, which are often attributable to biological factors. One such factor is the history of transplantation. However, there are still limited reports on such NIPS cases. We report an NIPS case of a pregnant woman who had received a stem cell transplant from a male donor. To determine the karyotype in the woman's original cell, we performed chromosome microarray analysis (CMA) on her postnatal blood and oral mucosa. To comprehensively estimate the cell-free DNA (cfDNA) composition, we further performed standard NIPS procedures on the postnatal plasma. Moreover, we reviewed all published relevant NIPS case reports about pregnant women with transplantation history. NIPS showed a low-risk result for common trisomies with a fetal fraction of 65.80%. CMA on maternal white blood cells showed a nonmosaic male karyotype, while the oral mucosa showed a nonmosaic female karyotype. The proportion of donor's cfDNA in postnatal plasma was 94.73% based on the Y-chromosome reads ratio. The composition of cfDNA in maternal plasma was estimated as follows: prenatally, 13.60% maternal, 65.80% donor, and 20.60% fetal/placental, whereas postnatally, 5.27% maternal and 94.73% donor. This study expanded our understanding of the influence of stem cell transplantation on NIPS, allowing us to optimize NIPS management for these women.

Infusion of Host-Derived Unlicensed NK Cells Improves Donor Engraftment in Non-Myeloablative Allogeneic Hematopoietic Cell Transplantation.

Allogeneic hematopoietic cell transplantation (allo-HCT) is an efficacious and frequently the only treatment option for some hematological malignances. However, it often faces severe morbidities and/or mortalities due to graft versus host disease, and the severity of the conditioning regiment needed, that result in toxicity-related issues poorly tolerable for some patients. These shortcomings have led to the development of less aggressive alternatives like non-myeloablative (NMAC) or reduced-intensity conditioning regiments (RIC). However, these approaches tend to have an increase of cancer relapse and limited persistence of donor-specific chimerism. Thus, strategies that lead towards an accelerated and more durable donor engraftment are still needed. Here, we took advantage of the ability of host-derived unlicensed NK (UnLicNK) cells to favor donor cell engraftment during myeloablative allo-HCT, and evaluated if the adoptive transfer of this cell type can improve donor chimerism in NAMC settings. Indeed, the infusion of these cells significantly increased mixed chimerism in a sublethal allo-HCT mouse model, resulting in a more sustainable donor cell engraftment when compared to the administration of licensed NK cells or HCT controls. We observed an overall increase in the total number and proportion of donor B, NK and myeloid cells after UnLicNK cell infusion. Additionally, the extension and durability of donor chimerism was similar to the one obtained after the tolerogenic Tregs infusion. These results serve as the needed bases for the implementation of the adoptive transfer of UnLicNK cells to upgrade NMAC protocols and enhance allogeneic engraftment during HCT.

P162 Use of an automated chimerism calculator to increase speed, precision, and statistical analysis of results

Aim Chimerism testing is a valuable tool for determining the proportion of donor vs. recipient DNA in a sample. The commonly used polymerase chain reaction amplifications of short tandem repeats assay (Promega, Madison, WI) produces results for 21 loci, but only 9 loci are used in manual calculations. We sought to improve the tedious and time consuming process of manually calculating a patient’s percent chimerism by developing an automated chimerism calculator for rapid and accurate chimerism calculations based off of all 21 loci. Methods The calculator was developed using Microsoft Excel Macros and is able to report the percent donor chimerism +/− the margin of error. To determine whether precision is improved by using 21 loci, the results of a 21 loci analysis and a 9 loci analysis were compared in 111 patient samples. Additionally, each of the 21 loci was evaluated for its average deviation from the mean. Finally, 298 patient samples were analyzed by the program in order to determine if precision is equal at all chimerism percentages. Results When the same loci are analyzed, the chimerism calculator results are identical to the manual calculations, but completed in 10% of the time. The analysis of patient samples using 21 and 9 loci yielded, on average, chimerism percentages within 2.0% of each other. The average margin of error using 9 loci for analysis is 2.41% compared to 0.8% using all 21 loci. Among the 21 loci, the average deviation from the mean was found to range from 8.9% and 5.9%. Finally, we found that the average margin of error for patients between 90 and 100 percent donor chimerism is 0.19% while patients between 30 and 40 percent donor chimerism have 10.1% margin of error. Conclusions The chimerism calculator allows for routine use of all 21 STR loci with significantly reduced analysis time, 30% less margin of error, and an informative statistical analysis. In various laboratory settings, similar methods of computer assisted chimerism analysis can be easily implemented.

Effect of doping on amplitude modulation of space-charge wave in semiconductor quantum plasma

To describe the modulational instability of space-charge waves in an n-type compensated semiconductor plasma, a nonlinear Schrodinger equation has been derived by using quantum hydrodynamical model and standard multiple scale perturbation technique. It has been shown that compensation factor (i.e. relative proportion of donor, acceptor and intrinsic carrier concentrations) and quantum diffraction parameter play important role in generating bright and dark envelope solitons within the semiconductor. Instability growth rate is also found to depend sensitively on the compensation factor and quantum diffraction parameter. From the linear dispersion relation it has been found that inclusion of quantum parameter gives rise to two new wave modes of purely quantum origin. Further the effect of compensation factor and quantum diffraction parameter on the linear dispersion characteristics has been analyzed. It has also been found that due to parabolicity of conduction band the group velocity of space-charge wave becomes dependent on compensation factor and quantum diffraction parameter.

Application of Sensitive AlleleSEQR Chimerism PCR from Peripheral Blood in Allografted AML/MDS Patients Treated with Pre-emptive Posttransplant Immunomodulation

PCR technique based on short tandem repeats (STR, microsatellites) is currently most widely used to monitor chimerism after allogeneic hematopoietic stem cell transplantation. Analysis of the proportion of donor and recipient derived cells enables an early detection of graft rejection or secondary graft failure. In malignant diseases increasing recipient chimerism has also been used to predict relapse, particularly in patients who lack disease-specific PCR marker to detect minimal residual disease (MRD). In these patients serial chimerism analyses may guide the use of post-transplant pre-emptive immunomodulation with the goal of avoiding clinical relapse. However, the sensitivity of the recently standardized STR-PCR, ranging between 0.8 and 1.6%, may not be sufficient to allow detection of impending relapse early enough in rapidly proliferating diseases like acute myeloid leukemia (AML) [1]. Therefore, we have tested the Abbott AlleleSEQR chimerism analysis system in AML patients who received pre-emptive post-transplant immunomodulation. The patients were routinely investigated for chimerism with STR-PCR monthly from whole blood and from blood T-cell fraction during post-transplant period and from bone marrow CD34 positive precursor cell fraction at 2-3 month intervals. In high risk patients with AML or myelodysplastic syndrome (MDS), we have applied posttransplant immunomodulation with azacytidine, lenalidomide and/ or donor lymphocyte infusions (DLI) based on findings in MRD and chimerism analyses the target being MRD negativity and full donor chimerism. In this retrospective study the routinely collected samples were additionally analyzed by Abbott AlleleSEQR chimerism assay.

The effect of the mixed external donors on the sequence length distribution of polypropylene

AbstractThe effects of different mixed external donors on the crystallization behavior and sequence length distribution of polypropylene prepared by MgCl2‐supported TiCl4 Ziegler–Natta catalyst were studied through successive self‐nucleation and annealing (SSA) technique. The SSA results show that the crystallization ability and the relative contents of long isotactic sequence length gradually increase with the increase of the relative component of Donor‐1 (cyclohexylmethyldimethoxysilane, dicyclohexyl(dimethoxy)silane, and dipiperidinedimethoxysilane) in the different mixed external donors when the ratio of the mixed external donors/Ti (Si/Ti) is unchanged. The thickness distribution of lamellar also becomes broader, indicating the sequence length distribution of polypropylene gets broader. The crystallization ability and the relative contents of long isotactic sequence length of polypropylene prepared by the mixed cyclohexylmethyldimethoxysilane and n‐propyltriethoxysilane (CN) external donors are lowest. However, the effect of the mixed dicyclohexyl(dimethoxy)silane and n‐propyltriethoxysilane (HN) and the mixed dipiperidinedimethoxysilane and n‐propyltriethoxysilane (PyN) external donors on the crystallization ability and sequence length of polypropylene are more significantly. Especially, the relative content of long isotactic sequence length increases sharply from 0.2 to 27.5% in the polypropylene chain of sample prepared by the mixed PyN external donors when the proportion of Donor 1 is running up to 90%. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Reconstitution of CD52-Negative CD4 T Cells after Alemtuzumab-Based T Cell Depleted Allogeneic Hematopoietic Stem Cell Transplantation

The human CD52 molecule is the target of the monoclonal antibody Alemtuzumab, which is used for treating patients with chemo-refractory chronic lymphocytic leukemia as well as for T cell depletion (TCD) in the context of allogeneic hematopoietic stem cell transplantation (HSCT). The molecule is expressed on the surface of lymphocytes, dendritic cells and to a lesser extent on blood-derived monocytes. Previously, investigators have demonstrated that the surface expression of CD52 on T cells is down-regulated after in vitro incubation with Alemtuzumab. By treating purified human CD4 T cells over 4 hours with 10 μg/mL Alemtuzumab in medium supplemented with 10% human AB serum in vitro, we observed a strong decrease of CD52 expression by flow cytometry with a maximum 3–7 days after incubation. The CD52 down-regulation was also found at weaker intensity on CD8 T cells. From previous studies in chronic lymphocytic leukemia patients, it is known that Alemtuzumab treatment also leads to a down-regulation of CD52 on T cells in vivo. However, similar experiments have not been performed in allogeneic HSCT patients receiving Alemtuzumab in vivo for T cell depletion. We therefore analyzed the expression of CD52 on human peripheral blood mononuclear cells isolated at repeated time points from 22 allogeneic HSCT patients after reduced-intensity conditioning with fludarabine and melphalan and in vivo T cell depletion with Alemtuzumab (100 mg). Half of the patients received prophylactic CD8-depleted donor lymphocyte infusions (DLI) to promote immune reconstitution. By flow cytometry, we observed that the CD52 expression on monocytes, B cells, and natural killer cells remained unaltered after transplantation and was not influenced by the application of DLI. In contrast, the majority of CD4 T cells were CD52-negative (median, 72%) after transplantation and they remained CD52-negative in patients who did not receive DLI throughout the first year after HSCT. The permanent lack of CD52 expression could not be explained by a continuous effect of Alemtuzumab, because earlier studies have shown that the antibody is not present in active plasma concentrations beyond day +60 after HSCT. In contrast, patients receiving CD8-depleted DLI demonstrated a significant increase in the proportion of CD52-positive CD4 T cells. In three of our patients (DLI: n=2, non-DLI: n=1) we analyzed the donor chimerism of CD52-positive and CD52-negative CD4 T cells sorted with high purity by flow cytometry. Three months after HSCT (before DLI), the proportion of donor T cells was clearly higher among the CD52-negative compared to the small proportion of CD52-positive cells in all patients (44% vs. 10%, 83% vs. 0%, and 100% vs. 40%). In the patient who did not receive DLI, the donor T cell chimerism remained mixed in the CD52-negative and CD52-positive fractions on days 200 (CD52-negative: 95%; CD52-positive: 15%) and 350 (CD52-negative: 92%; CD52-positive: 65%). In contrast, the two patients receiving CD8-depleted DLI showed a strong increase in the proportion of CD52-positive CD4 T cells that were of complete donor origin. Altogether, CD52 is permanently down-regulated in reconstituting CD4 T cells following HSCT with an Alemtuzumab-based TCD regimen unless DLI are applied. Our data support the idea of an active mechanism for CD52 down-regulation in CD4 T cells that is not related to B cells and natural killer cells and that appears to differently affect donor and host T cells, respectively.

Open-identity donor insemination in the United States: is it on the rise?

Information about US donor insemination programs was reviewed to determine whether an increasing number are offering open-identity donation. Results indicate that indeed, numbers are rising and that the ratio of open-identity to anonymous sperm donors in a program increases the longer that the program has offered an open-identity option.

Accessory cell neoplasia as a result of the breakdown of immunological regulation?

We have previously shown that the injection of spleen cells from old individual donors into young syngeneic recipients has two unexpected consequences (1). Firstly, in most recipients there is a gradual increase in the proportion of donor T cells and, secondly, the majority of the recipients develop tumours. These also derive from the donor inoculum. According to the classification of Dunn (2) they are type B reticulum cell neoplasms (RCN-B). The tumour cells have neither T nor B cell characteristics, most constitutively express class-II antigens, and those that have so far been tested function as accessory cells in in vitro assays (3–5). We have therefore suggested that they are the neoplastic counterpart of normal lymphoid dendritic cells (6). In the present paper the relationship between the two consequences of the injection of old cells is explored, and a hypothesis proposed to account for the finding that similar tumours, also of donor origin, can be induced in recipients of young syngeneic lymphocytes if they are subjected to repeated extrinsic antigenic stimulation.

Interference of ouabain in cell-to-cell coupling

When mouse cells are co-cultured with human cells in medium containing 1 μM ouabain, the steady-state culture content of 86Rb + (a tracer for K +) is increased over that expected from the contents of the two types cultured separately. This increase is due to K + transfer, presumably through gap junctions. Rescue of the human cells, which are sensitive to 1 μM ouabain, by K + transfer from the mouse cells, which are not, may be expressed quantitatively by a function, index of cooperation, whose value for this combination of cells is usually 0.4–0.6. (In the absence of coupling, index of cooperation equals 0; theoretical maximum equals 1.0.) We now report that when the ouabain concentration was raised above 1 μM, the index of cooperation was correspondingly reduced. Similar observations were made on four different combinations of cells differing in sensitivity to ouabain but all capable of junctional communication under other conditions. The concentration of ouabain needed to block cooperation completely caused no detectable change in the steady-state K + content of the donor cell, and was unaffected by substitution of a more ouabain-resistant donor or by a two-fold change in the proportion of donor and recipient cells in the co-culture. In confirmation, we observed that transfer of tritium-labeled nucleotides between cells was also blocked by treatment with ouabain. We interpret these results as indicating that ouabain interferes with functional communication, perhaps because of a local concentration of sensitive pump sites in junctional regions of the membrane, or because of inhibitory factors such as increased intracellular free Ca 2+, that might result directly or indirectly from ouabain binding to the Na +,K +-ATPase.

Functional half-life of virgin and primed B lymphocytes.

The functional half-life, a measure of the persistence of lymphocytes in an antigen-free environment, has been estimated and found to be about 7 days for virgin 2,4,6-trinitrophenyl (TNP)-reactive mouse B cells, and 2--3 times longer for TNP-primed B cells. Using allotype-congenic mice, lymph node cells were transferred from virgin or primed CBA/Igb donors to normal CBA/Iga recipients, and the proportion of donor B cells estimated at intervals...

Early cellular events in a systemic graft-vs.-host reaction. II. Autoradiographic estimates of the frequency of donor lymphocytes which respond to each Ag-B-determined antigenic complex.

A graft-vs.-host (GVH) reaction was initiated by the intravenous injection of parental strain (AO) lymphocytes into irradiated (AO times HO)F1 or (AO times DA)F1 hybrids. The proportion of donor T cells which had responded to the F1 hybrid antigens within 24 h was estimated by two methods. (a) Donor lymphocytes were labeled with [3H]uridine in vitro before injection. The proportion of labeled cells which had morphologically transformed in the recipient's spleen was 17-19%. In both series of experiments syngeneic transfers were performed in which case the proportion of transformed cells was 1-2.4%. A similar low proportion was found after parental to F1 transfer in a non-Ag-B strain combination. These figures were used to calculate the frequency of responding cells in the injected population given three additional pieces of information: (a) the extent of selection in the spleen which transformed the estimate to 4.5%-6.0% responders; (b) division of donor cells was shown to be negligible under the conditions of the experiment; and (c) the nonspecific recruitment of lymphocytes was shown to be negligible. A speculative model of antigen recognition by T cells which accounts for the high proportion of responders is outlined.