Leukemia escape in immune desert: intraocular relapse of pediatric pro-B-ALL during systemic control by CD19-CAR T cells.

During systemic control of BCP-ALL through CD19-CAR T cells, relapse can emerge in the eye as an immune-privileged organ. Ocular symptoms after CD19-CAR T-cell therapy should guide the clinician to elucidate the etiology in a timely fashion in order to adjust leukemia treatment strategy. Both, local immune escape as well as insufficient CAR T-cell persistence may have contributed to relapse in the reported patient. Mechanisms of relapse in an immune desert under CAR T-cell therapy require future clinical and experimental attention. In particular, ocular symptoms after CAR T-cell therapy should be considered a potentially early sign of leukemia relapse.