Discussion
In the absence of any other condition to explain this clinical picture and the good response to GVHD treatment indicate that the triggering factor in the development of GVHD may be COVID-19 in the era of TLR, which plays a common role in the pathogenesis of both GVHD and COVID-19.
Key words: Bone marrow transplantation, children, COVID-19, GVHD