Sarcopenia and gut microbiota alterations in patients with hematological diseases before and after hematopoietic stem cell transplantation

Objective: The aim of this study was to investigate the prevalence of sarcopenia(SP) and its relationship with gut microbiota alterations in patients with hematological diseases before and after hematopoietic stem cell transplantation(HSCT).Methods: A total of 108 patients with various hematological disorders were selected from Peking University People’s Hospital. SP was screened and diagnosed based on the 2019 Asian Sarcopenia Diagnosis Strategy. Physical measurements and fecal samples were collected, and 16S rRNA gene sequencing was conducted. Alpha and beta diversity analyses were performed to evaluate gut microbiota composition and diversity.Results: After HSCT, significant decreases in calf circumference and body mass index(BMI) were observed,accompanied by a decline in physical function. Gut microbiota analyses revealed significant differences in the relative abundance of Enterococcus, Bacteroides, Blautia and Dorea species before and after HSCT(P<0.05). Before HSCT, sarcopenic patients had lower Dorea levels and higher Phascolarctobacterium levels than non-sarcopenia patients(P<0.01). After HSCT, no significant differences in species abundance were observed. Alpha diversity analysis showed significant differences in species diversity among the groups, with the highest diversity in the postHSCT 90-day group and the lowest in the post-HSCT 30-day group. Beta diversity analysis revealed significant differences in species composition between pre-and post-HSCT time points but not between SP groups. Linear discriminant analysis effect size(LEfSe) identified Alistipes, Rikenellaceae, Alistipes putredinis, Prevotellaceae defectiva and Blautia coccoides as biomarkers for the pre-HSCT sarcopenia group. Functional predictions showed significant differences in anaerobic, biofilm-forming and oxidative stress-tolerant functions among the groups(P<0.05).Conclusions: This study demonstrated a significant decline in physical function after HSCT and identified potential gut microbiota biomarkers and functional alterations associated with SP in patients with hematological disorders. Further research is needed to explore the underlying mechanisms and potential therapeutic targets.

Nutritional assessment with different tools in leukemia patients after hematopoietic stem cell transplantation

Objective： Correct nutritional assessment is essential for leukemia patients after hematopoietic stem cell transplantation （HSCT）. This study aimed to investigate the best nutritional assessment method for leukemia patients after HSCT, and find the possible nutritional risk of the patients during the transplantation process in order to intervene in the patients with nutritional risks and undernourished patients timely, so that the entire transplantation process could be successfully completed. Methods： A prospective study was performed in 108 leukemia patients after HSCT, and different nutritional assessment methods, including nutritional risk screening 2002 （NRS2002）, mini nutritional assessment （MNA）, subjective globe assessment （SGA） and malnutritional universal screening tools （MUST）, were used. The associations between nutritional status of these patients and nutritional assessment methods were analyzed. Results： A total of 108 patients completed SGA, and 99 patients completed NRS2002, MNA and MUST. During the treatment process, 85.2% of the patients lost weight, wherein, 50% lost weight greater than 5%, and 42.6% had significantly reduced food intake. For nutritional risk assessment, the positive rates of NRS2002, MNA and MUST were 100%, 74.7% and 63.6%, respectively. There was a significant difference （P〈0.05） among the positive rates of NRS2002, MNA and MUST. In undernutrition assessment, the positive rate of SGA （83.3%） was significantly higher than that of MNA （17.2%） （P〈0.05）, and the incidence rate of nutritional risk among leukemia patients _〈30 years old was greater than that of patients 〉30 years old （P〈0.05）. Conclusions： Patients with leukemia were in poor nutritional status during and after HSCT. The leukemia patients 〈30 years old had a greater incidence rate of nutritional risk. As nutritional risk screening tool, the specificity of NRS2002 is not high, but it can be used for evaluating nutritional deficiencies. MNA is a good nutritional risk screening tool, but not an adequate tool for nutritional assessment. If assessment of undernutrition is necessary, the combination of all these screening tools and clinical laboratory indicators should he applied to improve accuracy.

Comprehensive evaluation of nutritional status before and after hematopoietic stem cell transplantation in 170 patients with hematological diseases

Objective： To investigate the nutritional status of patients before and after hematopoietic stem cell transplantation（HSCT）, and explore optimal methods for assessing nutritional status in patients with hematological diseases.Methods： This cohort study enrolled 170 patients who were diagnosed with hematological diseases and underwent allogeneic HSCT in the Department of Hematology, Peking University People＇s Hospital between May2011 and April 2013. We used fixed-point continuous sampling and four nutritional screening tools, Nutritional Risk Screening 2002（NRS-2002）, Mini Nutritional Assessment（MNA）, Subjective Global Assessment（SGA） and Malnutrition Universal Screening Tools（MUST）, in combination with body measurements, to extensively screen and evaluate nutritional risks and status in patients receiving HSCT before entering and after leaving laminar air flow rooms.Results： After HSCT, patients had significant reduction in weight, hip circumference, waist-hip ratio, calf circumference, mid-upper arm circumference, and suprailiac skinfold thickness compared with pre-HSCT measurements. Before HSCT, NRS-2002 identified that 21.2% of patients were at nutritional risks, compared with100% after HSCT. MUST indicated that before HSCT, 11.77% of patients were at high nutritional risk,compared with 59.63% after HSCT. MNA assessed that 0.06% of patients were malnourished before HSCT,compared with 19.27% after HSCT. SGA identified that before HSCT, 1.76% of patients had mild to severe malnutrition, which increased to 83.3% after HSCT. There is a significant increase in the nutritional risk and malnutrition in patients who received HSCT.Conclusions： Before HSCT, some patients already had nutritional risk or nutritional deficiencies, and prompt and close nutritional screening or assessment should be performed. The nutritional status of patients after HSCT was generally deteriorated compared with that before transplantation. Body measurements should be taken more frequently during the subsequent treatment window in the laminar air flow rooms. After HSCT, it is recommended to combine MNA and SGA to fully evaluate the nutritional status, and thus provide timely and reasonable nutritional support.

Inhibition of SIRT6 in prostate cancer reduces cell viability and increases sensitivity to chemotherapeutics

SI RT6 is an important histone modifying protein that regulates DNA repair,telomere maintenance,energy me-tabolism,and target gene expression.Recently SIRT6 has been identifi ed as a tumor suppressor and is down-regulated in certain cancer types,but not in other can-cers.From deposited gene profi ling studies we found that SIRT6 was overexpressed in prostate tumors,compared with normal or paratumor prostate tissues.Tissue micro-array studies confi rmed the higher levels of SIRT6 in both prostate tumor tissues and prostate cancer cells than in their normal counterparts.Knockdown of SIRT6 in human prostate cancer cells led to sub-G1 phase arrest of cell cy-cle,increased apoptosis,elevated DNA damage level and decrease in BCL2 gene expression.Moreover,SIRT6-de-fi ciency reduced cell viability and enhanced chemothera-peutics sensitivity.Taken together,this study provides the fi rst evidence of SIRT6 overexpression in human prostate cancer,and SIRT6 regulation could be exploited for pros-tate cancer therapy.