Keywords: Bone Marrow Transplantation, Graft versus Host Disease, hematopoiesis, THC, CBD

Bone Marrow Transplantation (BMT) is a well-established treatment for malignant and non-malignant hematological diseases. Allogeneic transplantation comes with the risk of Graft versus Host Disease (GVHD), a major cause of morbidity and mortality in BMT patients. In addition, the toxicity of the conditioning protocol which precedes BMT impairs innate and adaptive immunity, making transplanted patients very susceptible to both common and unusual infections.

In the past few years, numerous publications have reported the potential of cannabis-based medicines for the treatment of various conditions. Among the patients who can benefit from such treatment are BMT patients, who often suffer from nausea and chronic pain.

Cannabis contains more than 60 chemical compounds classified as cannabinoids.  In addition to their effect on the nervous system, cannabinoids also impart important immunological effects. Although a lot of information has been gathered regarding the influence of cannabinoids on the immune response, the effect of these drugs on rehabilitation of the hematological system after BMT and their efficacy in GVHD patients is largely unknown. Cannabis treatment was shown to reduce GVHD in a mouse model that did not include BMT and a recent publication demonstrated the beneficial effect of the cannabinoid CBD in GVHD patients, but other cannabinoids were not examined.

We hypothesize that cannabinoids have a selective effect on hematopoietic and immune cells and therefore different cannabinoids would have different effects on hematopoiesis and on GVHD. In our study we aim to provide data about the influence of different cannabinoids on hematopoiesis and as GVHD therapy after BMT. We use both in vivo and in vitro models to test the effect of cannabinoid treatment (CBD, THC and cannabis extracts) on immune activation, on rehabilitation of the hematologic system after BMT and on the clinical condition of mice with GVHD.

Our preliminary results demonstrate some of the effects of cannabis extract and cannabinoids on immune activation and on rehabilitation of hematological cells after BMT.

A better understanding of the effects of different cannabinoids on hematological reconstitution and GVHD pathology will allow the use of specific cannabinoid drug for each individual patient: as personalized medicines.