Reply:

We greatly appreciate the authors' interest in our work and thank them for their contribution to the discussion. Not having encountered a case of immune reconstitution inflammatory syndrome (IRIS) with progressive multifocal leukoencephalopathy (PML) in our institution, we hypothesized possible MR spectroscopic findings in our article, which were confirmed by the authors' communication. The authors' example showed elevated choline and mildly elevated myo-inositol peaks as we postulated in our article in addition to a lactate peak. These spectroscopic abnormalities presumably reflect an intense inflammatory response associated with the PML-IRIS. The baseline MR spectroscopy before development of PML-IRIS helped to elucidate the metabolic changes attributable to PML-IRIS.