The current and future role of stem cells in myelodysplastic syndrome therapies

Insights into gut microbiomes in stem cell transplantation by comprehensive shotgun long-read sequencing

The gut microbiome is a diverse ecosystem, dominated by bacteria; however, fungi, phages/viruses, archaea, and protozoa are also important members of the gut microbiota. Exploration of taxonomic compositions beyond bacteria as well as an understanding of the interaction between the bacteriome with the other members is limited using 16S rDNA sequencing. Here, we developed a pipeline enabling the simultaneous interrogation of the gut microbiome (bacteriome, mycobiome, archaeome, eukaryome, DNA virome) and of antibiotic resistance genes based on optimized long-read shotgun metagenomics protocols and custom bioinformatics. Using our pipeline we investigated the longitudinal composition of the gut microbiome in an exploratory clinical study in patients undergoing allogeneic hematopoietic stem cell transplantation (alloHSCT; n = 31). Pre-transplantation microbiomes exhibited a 3-cluster structure, characterized by Bacteroides spp. /Phocaeicola spp., mixed composition and Enterococcus abundances. We revealed substantial inter-individual and temporal variabilities of microbial domain compositions, human DNA, and antibiotic resistance genes during the course of alloHSCT. Interestingly, viruses and fungi accounted for substantial proportions of microbiome content in individual samples. In the course of HSCT, bacterial strains were stable or newly acquired. Our results demonstrate the disruptive potential of alloHSCTon the gut microbiome and pave the way for future comprehensive microbiome studies based on long-read metagenomics.

The role, targets and mechanisms of traditional Chinese medicine in regulating the balance of T helper type 17/regulatory Tcells in rheumatoid arthritis

Rheumatoid arthritis (RA) is a persistent systemic autoimmune disease, having all the hallmarks of joint swelling, joint tenderness, and progressive joint destruction, with synovitis and pannus formation as the basic pathological changes. T-lymphocyte infiltration is the key to its pathogenesis. During the growth of RA, the share of regulatory T (Treg) cells decreases, while the percentage of T helper type 17 (Th17) cells increases, giving rise to an imbalance of Th17/Treg cells. Modern medicine has made great advances in the treatment of RA and the selection of available drugs, but there are also the disadvantages of gastrointestinal reaction, high price, and low patient compliance. Therapy of RA remains a problem. Traditional Chinese medicine (TCM) has RA therapy developments, both in experimental research and clinical research, and its advantages of lasting effects and less detrimental reactions and fewer adverse effects are accepted by most patients. Numerous clinical and experimental studies have been performed in TCM on regulating Th17/Treg balance. However, the detailed mechanism of TCM intervention in Th17/Treg equilibrium in preventing and treating RA has not been discovered. In this article, the theory of regulating Th17/Treg cell equilibrium in RA is described from the perspectives of single Chinese medicine, active components of Chinese medicine, Chinese medicine compounds, and other therapies of TCM. It was found that TCM can regulate Th17/Treg cell balance and inhibit immunoreaction by intervening in cytokines, transcription factors, and signal pathways. It enables us to comprehensively and deeply understand the mechanism of TCM intervening in Th17/Treg balance in RA; provides direction for clinical therapy of RA; and offers new thoughts for understanding the pathogenesis of RA.

Persistence to hypomethylating agents and clinical and economic outcomes among patients with myelodysplastic syndromes

OBJECTIVES

To evaluate hypomethylating agent (HMA) persistence in patients with myelodysplastic syndromes (MDS), and examine its association with healthcare resource utilization (HRU) and progression to acute myeloid leukemia (AML).

METHODS

A total of 2,400 adults diagnosed with MDS initiating HMAs were included from IBM MarketScan databases during 1/1/2011-3/31/2018. The index date was HMA initiation following MDS diagnosis. Patients were classified according to their persistence status by the end of a fixed 'landmark period' of 4 months post-index.

RESULTS

Median persistence to HMAs was 5.6 months (95% CI: 5.2, 6.1); HMA non-persistence increased with time. Non-persistent patients had a significantly higher non-HMA-related HRU burden than persistent patients [adjusted incidence rate ratios, outpatient visits: 1.12 (95% CI: 1.10, 1.14); inpatient visits: 1.48 (95% CI: 1.30, 1.69); emergency department visits 1.30 (95% CI: 1.12, 1.50); all p-values < 0.001]. All-cause and HMA-related outpatient visits were lower among non-persistent patients, likely because of fewer HMA administration-related visits. The incidence rate of AML was numerically, although not significantly, higher in non-persistent patients, when starting follow-up at the end of the landmark period. When follow-up began at the index date, non-persistent patients had a significantly higher rate of AML [adjusted hazard ratio, 1.88 (95% CI: 1.53, 2.32); p-value < 0.001].

CONCLUSIONS

HMA non-persistence, which increased over time, was associated with significantly higher non-HMA-related HRU, and numerically higher AML progression in MDS patients initiating HMAs. Future studies should evaluate predictors of HMA non-persistence in this patient population.

Novel therapies in low- and high-risk myelodysplastic syndrome

Introduction: Myelodysplastic syndromes (MDS) comprise a heterogeneous group of myeloid neoplasms with diverse clinical courses. The revised version of the international prognostic scoring system (IPSS-R) provides risk stratification into 5 different groups. Areas covered: For lower-risk patients, red blood cell transfusions and iron chelation are the backbone of supportive care. In addition, erythropoiesis-stimulating agents (ESA) are used to ameliorate anemia. Lenalidomide is approved for the treatment of lower-risk patients with del(5q) who are transfusion-dependent. Patients with higher-risk disease should be offered allogeneic stem cell transplantation whenever possible. If they are unfit for transplantation or an appropriate donor cannot be found, hypomethylating agents may be used. Expert opinion: New therapeutic options for lower-risk patients include thrombopoietin analogues, the TGF-beta family ligand trapping drug Luspatercept, and the telomerase inhibitor Imetelstat. Combinations of hypomethylating agents (HMA) with other compounds, and inhibitors of bcl2, such as venetoclax are being developed for higher-risk patients. Finally, hypomethylating agents in combination with donor lymphocytes may lead to long-term remission following molecular or hematological relapse after allogeneic SCT.