New experiments have deciphered how disruptions to the body’s lymphatic system may drive lung and heart fibrosis in recipients of organ transplants – and have identified several potential therapeutic approaches to halt lung fibrosis in mice. By uncovering new treatment targets in transplant fibrosis, the findings could inform strategies to prevent one of the deadliest contributors to organ transplant rejection. Organ transplants tend to disrupt the delicate supportive network of lymphatic tissues that surrounds most organs, especially because these tissues aren’t reconnected during transplantation. This can lead to dysfunction in the lymphatic system and the accumulation of lymph fluids, or lymphedema. Researchers are beginning to suspect that lymphedema and similar complications could be major factors behind chronic rejection, which occurs in as many as half of transplant recipients after ten years. However, more research is needed to fill in the missing pieces of this puzzle. Hailey Shepherd and colleagues examined chronically rejected human heart and lung grafts and found strong evidence of fibrosis distributed across lymphatic vessels. These fibrotic areas contained unusually high levels of hyaluronan, a molecule that is normally drained by the lymphatic system. Further studies of mouse heart and lung grafts revealed that hyaluronan accumulated due to the secretion of the signaling molecule interleukin-1β by neutrophils. However, treating mice with an inhibitor that prevents the synthesis of hyaluronan or with a molecule that accelerates the growth of new lymphatic vessels prevented the rejection of lung grafts. “At a minimum, current surgical techniques of transplantation should be carefully reconsidered, particularly the stripping of lymphatic and adipose tissue surrounding anastomotic cuffs that is commonly performed during solid organ transplantation,” Shepherd et al. argue in their discussion.

About The Study: Given increasing rates of coronary artery disease (CAD) worldwide, the findings of this study of marked variation in radiation dose to patients from diagnostic testing identify a critical need for training, standardized protocols, and updated equipment to reduce radiation worldwide. This especially affects patients in low- and middle-income countries and patients undergoing coronary computed tomography angiograph. There are therefore important opportunities to improve the quality of CAD diagnosis for patients across the globe.

Over the next 25 years, the number of women living with cardiovascular disease is expected to rise sharply, as nearly 60% of women in the U.S. could have high blood pressure by 2050, up from about 5 in 10 previously reported for 2020, according to projections outlined in a new scientific statement from the American Heart Association.

Almost half of patients hospitalised for acute heart failure in Europe are readmitted within a year, according to a new study led by researchers at Karolinska Institutet and published in the European Heart Journal. The risk of death also remains high, especially for those with more severely reduced heart function.