Diagnostic tools in the indications for allogeneic stem cell transplantation in myelodysplastic syndromes

Non-Specific Binding, a Limitation of the Immunofluorescence Method to Study Macrophages In Situ

Advances in understanding tissue regenerative mechanisms require the characterization of in vivo macrophages as those play a fundamental role in this process. This characterization can be approached using the immuno-fluorescence method with widely studied and used pan-markers such as CD206 protein. This work investigated CD206 expression in an irradiated-muscle pig model using three different antibodies. Surprisingly, the expression pattern during immunodetection differed depending on the antibody origin and could give some false results. False results are rarely described in the literature, but this information is essential for scientists who need to characterize macrophages. In this context, we showed that in situ hybridization coupled with hybridization-chain-reaction detection (HCR) is an excellent alternative method to detect macrophages in situ.

Cytogenetic as an important tool for diagnosis and prognosis for patients with hypocellular primary myelodysplastic syndrome

We analyzed cytogenetically 105 patients with hypocellular primary MDS and their clinical implications. The main chromosomal abnormalities found were del(5q)/−5, del(6q)/+6, del(7q)/−7, del(11q), and del(17p). Pediatric patients had a higher frequency of abnormal karyotypes compared with adult patients (P < 0,05). From our patients, 18% showed evolution of the disease. The chromosomal abnormalities presented in the diagnosis of patients who evolved to AML included numerical (−7, +8) and structural del(6q), del(7q), i(7q), t(7;9), i(9q), and del(11q) abnormalities and complex karyotypes. Although the frequency of evolution from hypocellular MDS to AML is low, our results suggest that some chromosomal alterations may play a critical role during this process. We applied the IPSS in our patients because this score system has been proved to be useful for predicting evolution of disease. When we considered the patients according to group 1 (intermediate-1) and group 2 (intermediate-2 and high risk), we showed that group 2 had a high association with respect to the frequency of abnormal karyotypes (P < 0,0001), evolution of disease (P < 0,0001), and mortality (P < 0,001). In fact, the cytogenetic analysis for patients with hypocellular primary MDS is an important tool for diagnosis, prognosis, in clinical decision-making and in follow-up.

Myelodysplastic syndromes: who and when in the course of disease to transplant

The myelodysplastic syndromes are clonal hematopoietic disorders for which hematopoietic stem cell transplantation remains the only curative therapy. The timing of transplantation, methods of disease risk stratification, patient selection, pretransplantation therapies, and preparative regimens have evolved over the years, resulting in increasing disease-free survival. In recent years, alternative donor sources have been demonstrated to be a viable alternative to traditional sibling and matched unrelated donor stem cell sources. Efforts at transplantation regimen development continue with the aim of maximizing the chances of cure with minimal toxicity and improved quality of life. Integrating new knowledge regarding disease biology will be critical to continue to improve the success of hematopoietic stem cell transplantation. Exciting areas of ongoing research that may lead to reductions in posttransplantation relapse rate include posttransplantation therapies such as DNA methyltransferase inhibitors, vaccine strategies, and donor lymphocyte infusions to enhance the GVL effect.