PT - JOURNAL ARTICLE AU - Franziska Hopfner AU - Nora Möhn AU - Britta Eiz-Vesper AU - Britta Maecker-Kolhoff AU - Jens Gottlieb AU - Rainer Blasczyk AU - Nima Mahmoudi AU - Kaweh Pars AU - Ortwin Adams AU - Martin Stangel AU - Mike P. Wattjes AU - Günter Höglinger AU - Thomas Skripuletz TI - Allogeneic BK Virus-Specific T-Cell Treatment in 2 Patients With Progressive Multifocal Leukoencephalopathy AID - 10.1212/NXI.0000000000001020 DP - 2021 Jul 01 TA - Neurology - Neuroimmunology Neuroinflammation PG - e1020 VI - 8 IP - 4 4099 - http://nn.neurology.org/content/8/4/e1020.short 4100 - http://nn.neurology.org/content/8/4/e1020.full SO - Neurol Neuroimmunol Neuroinflamm2021 Jul 01; 8 AB - Objective Progressive multifocal leukoencephalopathy (PML) is a devastating demyelinating opportunistic infection of the brain caused by the ubiquitously distributed JC polyomavirus. There are no established treatment options to stop or slow down disease progression. In 2018, a case series of 3 patients suggested the efficacy of allogeneic BK virus-specific T-cell (BKV-CTL) transplantation.Methods Two patients, a bilaterally lung transplanted patient on continuous immunosuppressive medication since 17 years and a patient with dermatomyositis treated with glucocorticosteroids, developed definite PML according to AAN diagnostic criteria. We transplanted both patients with allogeneic BKV-CTL from partially human leukocyte antigen (HLA) compatible donors. Donor T cells had directly been produced from leukapheresis by the CliniMACS IFN-γ cytokine capture system. In contrast to the previous series, we identified suitable donors by HLA typing in a preexamined registry and administered 1 log level less cells.Results Both patients' symptoms improved significantly within weeks. During the follow-up, a decrease in viral load in the CSF and a regression of the brain MRI changes occurred. The transfer seemed to induce endogenous BK and JC virus-specific T cells in the host.Conclusions We demonstrate that this optimized allogeneic BKV-CTL treatment paradigm represents a promising, innovative therapeutic option for PML and should be investigated in larger, controlled clinical trials.Classification of Evidence This study provides Class IV evidence that for patients with PML, allogeneic transplant of BKV-CTL improved symptoms, reduced MRI changes, and decreased viral load.BKV-CTL=BK virus-specific T-cell; HLA=human leukocyte antigen; PML=progressive multifocal leukoencephalopathy; JCPyV=JC polyomavirus; JCVAI=anti-JC virus antibody index