Metabolic Syndrome after Hematopoietic Cell Transplantation: At the Intersection of Treatment Toxicity and Immune Dysfunction.

Hematopoietic cell transplantation (HCT) survivors face a multitude of short- and long-term health complications in the years after treatment. One important health complication that is associated with significant morbidity is metabolic syndrome (MetSyn). This constellation of findings, which includes obesity, glucose and lipid dysmetabolism, and hypertension, places affected individuals at increased risk for type 2 diabetes mellitus, cardiovascular complications, and stroke. Previous studies have linked MetSyn in HCT survivors to prior treatment; however, few studies have addressed the potential roles of systemic inflammation and immune system dysfunction after HCT. Within this review, we address the recent advances in the understanding of adipose tissue biology, immune, and inflammatory mechanisms involved in MetSyn in non-HCT patients, and lastly, we discuss potential novel mechanisms that may play a role in MetSyn development after HCT, such as hematopoietic stem cell source, inflammatory status of the stem cell donor, and microbiome composition, all of which represent potential new directions for post-HCT MetSyn research.