[Azacitidine therapy for low-risk myelodysplastic syndrome developing after solid organ transplantation]

Immunosuppressive therapy after solid organ transplantation is known to be a risk factor for the development of myelodysplastic syndromes (MDS). Herein, we report 2 patients, both of whom developed low-risk MDS after solid organ transplantation and were successfully treated with azacitidine (AZA). The 1st case was a 74-year-old man who had received liver transplantation. The initial immunosuppressive therapy consisted of cyclosporine and prednisolone. Nine years after transplantation, he was diagnosed as having MDS (RCMD). The 2nd case was a 47-year-old woman who had received cadaveric renal transplantation. The initial immunosuppressive therapy was comprised of cyclosporine, azathioprine, and prednisolone. Twenty-seven years after transplantation, she developed MDS (RA). Both patients received 75 mg/m² AZA once daily for five consecutive days on a 28-day cycle. After 2 courses of therapy, both patients achieved hematological improvement (IWG 2006 criteria) without severe (grade 3/4) non-hematological adverse events. Moreover, AZA did not affect the status of organ transplantation in terms of engraftment and function of the graft. In conclusion, AZA would be a safe and effective agent for patients with MDS after solid organ transplantation. However, long-term follow-up is needed to confirm the safety and efficacy of AZA for patients undergoing solid organ transplantations.

Dietary Variety and Decline in Lean Mass and Physical Performance in Community-Dwelling Older Japanese: A 4-year Follow-Up Study

OBJECTIVES

To examine associations of dietary variety with changes in lean mass and physical performance during a 4-year period in an elderly Japanese population.

DESIGN

Four-year prospective study.

SETTING

The Hatoyama Cohort Study and Kusatsu Longitudinal Study, Japan.

PARTICIPANTS

935 community-dwelling Japanese aged 65 years or older.

MEASUREMENTS

Dietary variety was assessed using a 10-item food frequency questionnaire. Body composition was determined by multifrequency bioelectrical impedance analysis, and physical performance (grip strength and usual gait speed) was measured in surveys at baseline and 4 years later. Longitudinal analysis included only participants who were originally in the upper three quartiles of lean body mass, appendicular lean mass, grip strength, and usual gait speed. The outcome measures were decline in lean body mass, appendicular lean mass, grip strength, and usual gait speed, defined as a decrease to the lowest baseline quartile level at the 4-year follow-up survey. Associations of dietary variety with the outcome measures were examined by logistic regression analysis adjusted for potential confounders.

RESULTS

In the fully adjusted model, the odds ratios for decline in grip strength and usual gait speed were 0.43 (95% confidence interval, 0.19-0.99) and 0.43 (confidence interval, 0.19-0.99), respectively, for participants in the highest category of dietary variety score as compared with those in the lowest category. Dietary variety was not significantly associated with changes in lean body mass or appendicular lean mass.

CONCLUSION

Among older adults, greater dietary variety may help maintain physical performance, such as grip strength and usual gait speed, but not lean mass.

Association of Dietary Variety with Body Composition and Physical Function in Community-dwelling Elderly Japanese

OBJECTIVES

To examine the associations of dietary variety with body composition and physical function in community-dwelling elderly Japanese.

DESIGN

Cross-sectional study.

SETTING

Community-based.

PARTICIPANTS

A total of 1184 community-dwelling elderly adults aged 65 and over.

MEASUREMENTS

Dietary variety was assessed with a food frequency questionnaire (maximum, 10 points) that encompassed the 10 main food components of Japanese meals (meat, fish/shellfish, eggs, milk, soybean products, green/yellow vegetables, potatoes, fruit, seaweed, and fats/oils). Body composition was determined by multifrequency bioelectrical impedance analysis. Physical function was assessed by measuring grip strength and usual walking speed. Multiple linear regression analysis was used to examine the associations of dietary variety with body composition and physical function.

RESULTS

After adjusting for potential confounders, higher dietary variety scores were independently associated with higher lean mass (β (SE): 0.176 (0.049), p<0.001) and appendicular lean mass (β (SE): 0.114 (0.027), p<0.001) but not with body fat mass. Elders with a higher dietary variety score had greater grip strength and faster usual walking speed (β (SE): 0.204 (0.071), p=0.004, and β (SE): 0.008 (0.003), p=0.012, respectively).

CONCLUSION

Greater dietary variety was significantly associated with greater lean mass and better physical function in Japanese elders. The causal relationship warrants investigation in a prospective study.

Clathrin assembly protein CALM plays a critical role in KIT signaling by regulating its cellular transport from early to late endosomes in hematopoietic cells

CALM is implicated in the formation of clathrin-coated vesicles, which mediate endocytosis and intracellular trafficking of growth factor receptors and nutrients. We previously found that CALM-deficient mice suffer from severe anemia due to the impaired clathrin-mediated endocytosis of transferrin receptor in immature erythroblast. However, CALM has been supposed to regulate the growth and survival of hematopoietic stem/progenitor cells. So, in this study, we focused on the function of CALM in these cells. We here show that the number of Linage⁻Sca-1⁺KIT⁺ (LSK) cells decreased in the fetal liver of CALM^−/− mice. Also, colony forming activity was impaired in CALM^−/− LSK cells. In addition, SCF, FLT3, and TPO-dependent growth was severely impaired in CALM^−/− LSK cells, while they can normally proliferate in response to IL-3 and IL-6. We also examined the intracellular trafficking of KIT using CALM^−/− murine embryonic fibroblasts (MEFs) engineered to express KIT. At first, we confirmed that endocytosis of SCF-bound KIT was not impaired in CALM^−/− MEFs by the internalization assay. However, SCF-induced KIT trafficking from early to late endosome was severely impaired in CALM^−/− MEFs. As a result, although intracellular KIT disappeared 30 min after SCF stimulation in wild-type (WT) MEFs, it was retained in CALM^−/− MEFs. Furthermore, SCF-induced phosphorylation of cytosolic KIT was enhanced and prolonged in CALM^−/− MEFs compared with that in WT MEFs, leading to the excessive activation of Akt. Similar hyperactivation of Akt was observed in CALM^−/− KIT⁺ cells. These results indicate that CALM is essential for the intracellular trafficking of KIT and its normal functions. Also, our data demonstrate that KIT located in the early endosome can activate downstream molecules as a signaling endosome. Because KIT activation is involved in the pathogenesis of some malignancies, the manipulation of CALM function would be an attractive therapeutic strategy.