BACKGROUND Thalassemia major can be cured with allogeneic hematopoietic stem cell transplantation. Persistent mixed chimerism develops in around 10% of transplanted thalassemic patients, but the biological mechanisms underlying this phenomenon are poorly understood. DESIGN AND METHODS The presence of interleukin-10-producing T cells in the peripheral blood of eight patients with persistent mi...

The failure of engraftment in human cases of in utero hematopoietic cell transplantation (IUHCT) in which no immunodeficiency exists suggests the presence of an unrecognized fetal immune barrier. A similar barrier in murine IUHCT appears to be dependent on the chimerism level and is poorly explained by a lack of T-cell tolerance induction. Therefore, we studied the effect of the chimerism level...

Introduction. In high-risk acute myeloid leukaemia/myelodysplastic syndrome patients, relapse remains the major cause of treatment failure after allogeneic stem cell transplantation (alloSCT). The investigation of lineage-specific chimerism has become an important tool in the management of patients during the post-transplant period. Aim. Early assessment of lineage specific chimerism in patient...

At present, the most common genetic diagnostic method for chimerism evaluation following hematopoietic stem cell transplantation is microsatellite analysis by capillary electrophoresis. The main objective was to establish, through repeated analysis over time, if a complete chimerism was present, or if the mixed chimerism was stable, increasing or decreasing over time. Considering the recent int...

Long-term stable mixed chimerism is a rare and poorly understood phenomenon post hematopoietic stem cell transplantation. This study aims to shed light on whether the two hematopoietic systems in patients with mixed chimerism remain functional. Additionally, we investigate possible immunologic differences in these individuals compared to patients with only donor derived immune cells. Patients w...

BACKGROUND Chimerism defines the amount of donor versus recipient hematopoiesis following allogeneic stem cell transplant (SCT). PCR-based analyses of short tandem repeats (STRs) are commonly used and are accurate and applicable to allogeneic transplant recipients. These analyses are performed on blood and marrow aspirates, but it is unknown if analyses of both are required. We performed a retr...

Human spontaneous chimerism, with one body built from cells of both twins of a dizygotic (DZ) pair, is supposed to be extremely rare, arising from the exchange of blood cells through placental anastomoses. Mosaicism is supposed to be far more common, arising from single zygotes by embryonic mutation. Because typical diagnosis of mosaicism can neither identify nor exclude chimerism, 'mosaicism' ...

OBJECTIVE To determine the frequency of mixed donor chimerism in patients of non-malignant haematological diseases after allogeneic bone marrow transplant. STUDY DESIGN A cross-sectional, observational study. PLACE AND DURATION OF STUDY Department of Haematology, Armed Forces Institute of Pathology (AFIP), Rawalpindi, from July 2010 to June 2011. METHODOLOGY Donor chimerism was assessed i...

BACKGROUND AND OBJECTIVE Fully quantitative cytological techniques for the analysis of hemopoietic chimerism are very limited and largely restricted to sex-chromosome detection after sex-mismatched bone marrow transplants (BMTs). The aim of the present investigation was to assess the usefulness of autosomal polymorphisms for the size of heterochromatic regions in the identification of donor and...

Chimerism occurs when two genetically distinct conspecific individuals fuse together generating a single entity. Coalescence and chimerism in red seaweeds has been positively related to an increase in body size, and the consequent reduction in susceptibility to mortality factors, thus increasing survival, reproductive potential and tolerance to stress in contrast to genetically homogeneous orga...