The microchimerism is a status of the microcell or DNA of an individual in another one with genetic differences. Taking an overall view about the discovery and research of the microchimerism, it was found that although the study of the microchimerism emphasizes the formation, origin, distribution, type, relationship to disease and several other aspects, the objects of the study are always the microchimerism that obtained naturally. As it is known to all, the microchimerism can also be produced in some clinical treatment, such as in the transplant and transfusion, but compared with the microchimerism gained naturally, obviously, the study for the iatrogenic microchimerism formed in the treatment is not elaborate enough. The curative effect of micro transplantation, a new technique for leukemia treatment, is obvious, but its mechanism is unclear, whether that is related to microchimerism still needs further research. This review summarizes the study history and perspective of the microchimerism so as to provide some ideas for studying the action mechanism of microchimerism in micro transplantation.
Chimerism ; DNA ; genetics ; Humans ; Transplantation Chimera

: AbstractObjective: To investigate the sample selection, result correction and clinical application value of multi nucleotide polymorphism chimerism detection method based on Next-generation sequencing. METHODS: The chimerism samples from November 2018 to June 2020 were collected, and Pearson correlation coefficient (r) was used to analyze the consistency of bone marrow and peripheral blood results detected by MNPseq; according to the different information integrity before transplantation, the calibration model was constructed to analyze the correction value of the micro chimerism results in each model; the clinical results were retrospectively analyzed to verify the reliability and practicability of chimerism results correction and the clinical value of MNPseq method. RESULTS: The results of bone marrow and peripheral blood chimerism detected by MNPseq method were consistent with each other and showed significant correlation (r=0.985, P<0.01). The three groups of calibration models were constructed according to different pre-transplant information. For the no donor and pre-transplant patients information group, the correction value was 1%; while for the group with pre-transplant patients and without donor information, 0.61% of the chimerism rate and 13 heterotopic points were used as the correction value; 0.26% of the chimerism rate and 21.57% of the heterotopic points were used as the correction value for the group with pre-transplantation patients and donor information. After correction, the number of the patients with incomplete chimerism decreased from 276 (74.19%) to 141 (37.91%) (P<0.01). Among 18 (18/141, 12.77%) patients with incomplete chimerism, the results of MNPseq in the patients were 25-39 days earlier than those in STR and flow MRD, and the result showed statistical significance. CONCLUSION MNPseq method can be used to monitor chimerism with peripheral blood instead of bone marrow samples, and the results can be corrected to detect the changes of graft status in vivo in a more timely manner.
Chimerism ; Hematopoietic Stem Cell Transplantation ; Humans ; Nucleotides ; Reproducibility of Results ; Retrospective Studies ; Transplantation Chimera/genetics* ; Transplantation, Homologous

To evaluate the roles of 8 short tandem repeats (STR) loci as STR panel in quantitative analysis of chimerism following transplantation, the primers were synthesized and marked with different dyes for D3S3045, D4S2366, D4S2639, D5S818, D13S317, D18S1002, D20S481 and D22S689. The blood samples of 15 cases received allogeneic stem cell transplantation were collected before and after transplantation, then DNA was extracted and amplified with these primers, and was further analysed under ABI Genetic Analyser 3100 to select suitable informative STR locus. Donor/recipient dilution series were prepared to get standard curves in selected loci, the DNAs extracted at different days after transplantation were used to quantitatively analyze the chimerism in patients according to the values of peak area or peak height of fluorescent signals. The standard curves can be used to calculate the chimerism by plotting the respective R/D quotient value against the percentage of recipient DNA. The results indicated that the calculated chimerism was in concordance with the donor/recipient dilution. The STR panel succeeded in identifying at least one informative marker and quantitative monitoring the chimerism after HSCT in 15 donor-recipient pairs and a relapsed case was diagnosed. It is concluded that the STR panel and its detection method can accurately and quantitatively monitor the chimerism after allogeneic HSCT, which is more economical and flexible than using commercial kits.
DNA ; genetics ; DNA Primers ; Hematopoietic Stem Cell Transplantation ; Humans ; Microsatellite Repeats ; Transplantation Chimera ; genetics

The aim of this study was to evaluate microchimerism after human liver transplantation (LT). This study included 13 female recipients who received hepatic allograft from male donors at Asan Medical Center. A nested PCR specific for Y-chromosome gene (DYZ3) was used to analyze the small number of male cells in the peripheral blood mononuclear cells of the female recipients. Microchimerism was observed in 6 of 13 recipients and 16 out of 35 samples. Only 3 patients showed microchimerism 3 months after LT. There was no statistical difference between the presence of microchimerism and clinical findings such as type of donor, type of immunosuppression, episode of rejection and age of recipient. This study did not show any clinical relevance of microchimerism and further larger study are needed to confirm the results.
Adolescence ; Adult ; Animal ; Child ; Child, Preschool ; Female ; Human ; Infant ; Liver Transplantation* ; Lymphocytes/immunology* ; Male ; Transplantation Chimera/immunology* ; Transplantation Chimera/genetics ; Y Chromosome

The aim of this study was to evaluate microchimerism after human liver transplantation (LT). This study included 13 female recipients who received hepatic allograft from male donors at Asan Medical Center. A nested PCR specific for Y-chromosome gene (DYZ3) was used to analyze the small number of male cells in the peripheral blood mononuclear cells of the female recipients. Microchimerism was observed in 6 of 13 recipients and 16 out of 35 samples. Only 3 patients showed microchimerism 3 months after LT. There was no statistical difference between the presence of microchimerism and clinical findings such as type of donor, type of immunosuppression, episode of rejection and age of recipient. This study did not show any clinical relevance of microchimerism and further larger study are needed to confirm the results.
Adolescence ; Adult ; Animal ; Child ; Child, Preschool ; Female ; Human ; Infant ; Liver Transplantation* ; Lymphocytes/immunology* ; Male ; Transplantation Chimera/immunology* ; Transplantation Chimera/genetics ; Y Chromosome

This study was aimed to establish a model for detecting the donor chimerism rate following the multi-donor hematopoietic stem cell transplantations, and simplify its calculation method. Patients with hematologic disease receiving allogeneic hematopoietic stem cell transplantation including single-donor and multi-donor were selected in this study and the donor cell chimerism rates were detected, using STR-PCR combined with capillary electrophoresis. The results indicated that the peaks of the sister alleles coming from the same individual were confirmed to have the approximate areas and can be replaced each other in the situation of mixed chimerism. In the calculation model, the value between reference chimerism and approximate chimerism have no significant difference using the hypothetical peak areas, and the result was confirmed to be accepted basing on typical measurement error between sister alleles (5% - 20%). It is concluded that the areas of share peaks can be replaced by non-share peaks and this conclusion can be used to calculate the double-donor CHM (DD-CHM)(%). Compared to the D alleles, R alleles show more strategic importance because it can lead to more accurate result and allowed simplifying the arithmetic calculations for DD-CHM(%).
Alleles ; Electrophoresis, Capillary ; Hematopoietic Stem Cell Transplantation ; Humans ; Polymerase Chain Reaction ; Postoperative Period ; Tissue Donors ; Transplantation Chimera ; genetics ; Transplantation, Homologous

Child ; Graft Survival ; HLA Antigens ; genetics ; immunology ; Hematopoietic Stem Cell Transplantation ; Humans ; Polymerase Chain Reaction ; Tissue Donors ; Transplantation Chimera ; genetics ; Transplantation Conditioning ; methods ; Transplantation, Homologous ; immunology

The purpose of this research was to monitor quantitatively and study the dynamic changes and development rules of engraftment, chimera types, as well as relative amount of donor cells after allogeneic transplantation of mixed umbilical-cord blood from two units. An adult patient with acute myeloid leukemia received two units HLA one locus mismatched unrelated umbilical cord blood transplantation (2.5 x 10(7)/kg karyocytes in umbilical cord blood unit 1, and 1.53 x 10(7)/kg karyocytes in umbilical cord blood unit 2). Nine STR loci of the blood sample before and after transplantation were determined by quantitative detecting technique with fluorescence labeling polymerase chain reaction, while the engraftment and chimera types were qualitatively evaluated by comparing differential loci between the recipient and the donors. Then the relative proportion of chimera from two units of umbilical-cord blood in the patient after transplantation was calculated according to the differential gene peak areas of two donors on 377XL DNA sequencer after fluorescence scanning, and the engraftment level and the development rules of donor cells were analyzed. In addition, the results were also compared with that of HLA loci distinct analysis for engraftment. The results showed that two umbilical cord blood units at 15 days after transplantation were engrafted simultaneously and revealed a complete chimerism of the two. The relative amounts of chimera from unit 1 vs that of unit 2 were 51.3% vs 48.7%; subsequently relative amounts of chimera from unit 1 went up to 70.0% at 30 days, and that from unit 2 declined to 30.0%. However, at 52 days, only the genotype of umbilical cord blood unit 1 was detected, so that the engraftment turned to a complete chimerism of a single donor type. The one with fewer karyocytes was rejected and the one with more karyocytes finally engrafted in long-term. It is concluded that quantitatively detecting STR chimera with fluorescence labeling polymerase chain reaction can depict precisely the engraftment level and the change course of two umbilical cord blood units. It provides an accurate and reliable experimental basis for clinical umbilical cord blood application and donor selection, and is proved to be feasible for adult transplantation by using dual unit of umbilical-cord blood with HLA one locus mismatched at the same time.
Adult ; Cord Blood Stem Cell Transplantation ; HLA-B Antigens ; genetics ; Humans ; Male ; Polymerase Chain Reaction ; Tandem Repeat Sequences ; Transplantation Chimera

The purpose of this study was to analyze the STR loci expression after allergenic cord hematopoietic stem cell transplantation in patient with Ducennes muscular dystropy (DMD) patient. PCR-SSO was used to identify the HLA antigens and alleles, STR-PCR was used to detect the chimera status. Quantity analysis of donor chimeras was performed by multiplex PCR amplification of STR marker and capillary electrophoresis with fluorescence detection. The results showed that patient appear to be HLA identical to the donor cord blood at the tested level. Persistent full donor chimerism was found in breast bone marrow. The patient with stable MC (DC < 5%) had a probability of long term survival with molecular remission MC status appeared in forearm muscle, tongue, liver, spleen, stomach, right temporal lobe, diaphragmatic muscle, bronchus, left ventricle and right kidney. In conclusion, the donor gene can express in parenchymatoas organs, the donor chimerism was detected in breast bone marrow and some other organs.
Child ; Cord Blood Stem Cell Transplantation ; Genetic Loci ; genetics ; Humans ; Male ; Microsatellite Repeats ; genetics ; Muscular Dystrophies ; genetics ; therapy ; Transplantation Chimera ; Transplantation, Homologous

Monitoring engraftment of donor cells after allogeneic transplantation is the key of assessing successful establishment of animal transplantation model. The purpose of this study was to establish a method for analysis of chimerism in rhesus transplantation model. Y-specific sequence in rhesus was amplified by the polymerase chain reaction (PCR), method for analysis of chimerism in rhesus after sex-mismatched transplantation was established; the feasibility and sensitivity of the approach were tested by using serial DNA mixtures of sex-mismatched individuals; the accuracy of results was confirmed by chromosome karyotype analysis simultaneously; Chimerisms of one rhesus received allogeneic stem cell transplantation and the other received mesenchymal stem cells (MSC) transfusion were detected by this method. The results showed that a 176 bp long sequence of PCR product was gained in male rhesus, while no product was gained in female rhesus. The sensitivity of this method was up to 0.05% (male/female DNA ratio). Male donor chimerism were found on day 7 and 14 after allogeneic stem cell transplantation by Y-specific sequence and chromosome karyotype analysis. Otherwise, male donor chimerism was found in peripheral blood at 1 hour and in bone marrow on day 30 after MSC transfusion by this method, but no male donor chimerism was found after MSC transfusion using chromosome karyotype analysis. In conclusion, this rapid, sensitive approach can used to assess chimerism in experiments of rhesus alloorgan transplantation and cell transfusion.
Animals ; Base Sequence ; Female ; Macaca mulatta ; Male ; Mesenchymal Stem Cell Transplantation ; methods ; Models, Animal ; Molecular Sequence Data ; Transplantation Chimera ; blood ; genetics ; Transplantation, Homologous ; Y Chromosome ; genetics