Emerging immunosuppressive drugs in myelodysplastic syndromes

The inflammatory cytokine profile of myelodysplastic syndromes: A meta-analysis

BACKGROUND

Accumulating evidence has indicated that the dysregulation of immunological environment has an important role in the pathogenesis of myelodysplastic syndromes (MDS). The previous studies about the levels of the inflammatory cytokines in MDS, such as TNF-α, IFN-γ, IL-6, IL-8, and IL-17, have yielded controversial results. Thus, we performed a meta-analysis to assess the levels of these inflammatory cytokines in MDS.

METHODS

A systematic search in PubMed, MEDLINE, Cochrane Library, Web of Science, CNKI, and CBM was conducted to find eligible studies. Meta-analyses were performed using STATA 12.0 for Windows. Heterogeneity between included studies was assessed by I test. We chose SMD as the summary statistic.

RESULTS

A total of 697 individuals from 11 studies were included in this study. Our results suggest the levels of TNF-α, IL-6, IL-8 were significantly higher in MDS patients compared with controls, SMD and 95%CI was 1.48 (0.60, 2.36), 0.71 (0.16, 1.25) and 0.69 (0.28, 1.09), respectively. Moreover, the levels of IL-17 have decreased in the high-risk MDS, the SMD and 95% CI was 2.96 (0.78, 5.15).

CONCLUSION

A close association between immunological microenvironment disorders and the pathogenesis of MDS was revealed in this meta-analysis. More importantly, the profiles of inflammatory cytokines appear to change along the progression of the disease.

Deregulation of innate immune and inflammatory signaling in myelodysplastic syndromes

Myelodysplastic syndromes (MDSs) are a group of heterogeneous clonal hematologic malignancies that are characterized by defective bone marrow (BM) hematopoiesis and by the occurrence of intramedullary apoptosis. During the past decade, the identification of key genetic and epigenetic alterations in patients has improved our understanding of the pathophysiology of this disease. However, the specific molecular mechanisms leading to the pathogenesis of MDS have largely remained obscure. Recently, essential evidence supporting the direct role of innate immune abnormalities in MDS has been obtained, including the identification of multiple key regulators that are overexpressed or constitutively activated in BM hematopoietic stem and progenitor cells. Mounting experimental results indicate that the dysregulation of these molecules leads to abnormal hematopoiesis, unbalanced cell death and proliferation in patients' BM, and has an important role in the pathogenesis of MDS. Furthermore, there is compelling evidence that the deregulation of innate immune and inflammatory signaling also affects other cells from the immune system and the BM microenvironment, which establish aberrant associations with hematopoietic precursors and contribute to the MDS phenotype. Therefore, the deregulation of innate immune and inflammatory signaling should be considered as one of the driving forces in the pathogenesis of MDS. In this article, we review and update the advances in this field, summarizing the results from the most recent studies and discussing their clinical implications.

Treatment of Crohn's disease complicated with myelodysplastic syndrome via allogeneic hematopoietic stem cell transplantation: case report and literature review

Crohn’s disease (CD) is a chronic inflammatory disease of the gastrointestinal tract arising in individuals with genetic predisposing factors and abnormalities of the immune system. Myelodysplastic syndrome (MDS), an acquired clonal hematologic disorder, is characterized by peripheral blood cytopenia, dysplastic changes in several types of hematopoietic cells of the bone marrow and peripheral blood, and a high risk of transformation to acute leukemia. CD rarely occurs in combination with MDS, and MDS treatment with hematopoietic stem cell transplantation (HSCT) has not been frequently reported. We report the case of a 50-year-old Chinese male who presented with abdominal pain, diarrhea, and fatigue. CD was diagnosed by colonoscopy, imaging studies, and pathological examination. He was initially treated with mesalazine and prednisone and thereafter he presented with pancytopenia. MDS (RAEB-I) was diagnosed by bone marrow examination, and karyotyping revealed 47, XY, +8. The patient was treated with thalidomide, andriol, and decitabine. Allogeneic HSCT was performed with a human leukocyte antigen-matched sibling as the donor. The patient is currently well at 14 months after HSCT, without abdominal pain, diarrhea, or fatigue. HSCT may be a promising treatment option for patients with combined CD and MDS.

Acquired myelodysplasia or myelodysplastic syndrome: clearing the fog

Myelodysplastic syndromes (MDS) are clonal myeloid disorders characterized by progressive peripheral blood cytopenias associated with ineffective myelopoiesis. They are typically considered neoplasms because of frequent genetic aberrations and patient-limited survival with progression to acute myeloid leukemia (AML) or death related to the consequences of bone marrow failure including infection, hemorrhage, and iron overload. A progression to AML has always been recognized among the myeloproliferative disorders (MPD) but occurs only rarely among those with essential thrombocythemia (ET). Yet, the World Health Organization (WHO) has chosen to apply the designation myeloproliferative neoplasms (MPN), for all MPD but has not similarly recommended that all MDS become the myelodysplastic neoplasms (MDN). This apparent dichotomy may reflect the extremely diverse nature of MDS. Moreover, the term MDS is occasionally inappropriately applied to hematologic disorders associated with acquired morphologic myelodysplastic features which may rather represent potentially reversible hematological responses to immune-mediated factors, nutritional deficiency states, and disordered myelopoietic responses to various pharmaceutical, herbal, or other potentially myelotoxic compounds. We emphasize the clinical settings, and the histopathologic features, of such AMD that should trigger a search for a reversible underlying condition that may be nonneoplastic and not MDS.