Cerebrospinal fluid chimerism analysis in patients with neurological symptoms after allogeneic cell transplantation

Low donor chimerism may be sufficient to prevent demyelination in adrenoleukodystrophy

Adrenoleukodystrophy (ALD) is a peroxisomal disorder characterized by white matter degeneration caused by adenosine triphosphate-binding cassette subfamily D member 1 (ABCD1) gene mutations, which lead to an accumulation of very-long-chain fatty acids (VLCFA). Hematopoietic stem cell transplantation (HSCT) is the most effective treatment; however, the ratio of donor-to-recipient cells required to prevent the progression of demyelination is unclear. The proband was diagnosed with the childhood cerebral form of ALD at 5 years of age based on the clinical phenotype, elevated plasma VLCFA levels, and pathogenic ABCD1 mutation c.293C>T (p.Ser98Leu). Soon after the diagnosis, he became bedridden. At 1 year of age, his younger brother was found to carry the same ABCD1 mutation; despite being asymptomatic, at 1 year and 9 months, head magnetic resonance imaging (MRI) showed high-signal-intensity lesions in the cerebral white matter. The patient underwent unrelated cord blood transplantation (UCBT) with a reduced conditioning regimen, which resulted in mixed chimerism. For 7 years after UCBT, the donor chimerism remained low (<10%) in peripheral blood and cerebrospinal fluid. However, even though a second HSCT was not performed, his neurological symptoms and brain MRI findings did not deteriorate. Our case suggests that even a small number of donor cells may prevent demyelination in ALD. This is an important case when considering the timing of a second HSCT.

Graft-versus-host disease of the central nervous system after liver transplantation: A rare complication

Graft-versus-host disease (GVHD) of the central nervous system (CNS) following solid organ transplantation is a rare but serious complication and has been previously reported after bone marrow transplantation. GVHD after liver transplantation is a rare entity with a high mortality rate. We report the case of a patient who developed GVHD and subsequently had seizures and altered mental status after deceased donor liver transplantation. The diagnosis of GVHD of the CNS was established by short tandem repeat loci analysis of the cerebrospinal fluid using the polymerase chain reaction technique and gene mapping software. To our knowledge, this is the first reported case of CNS-GVHD following liver transplantation. He eventually died of sepsis and multiorgan failure, in keeping with the overall poor prognosis of CNS-GVHD.

Donor cell chimerism evaluation in cerebrospinal fluid by short tandem repeat analysis following allogeneic hematopoietic stem cell transplantation

Cerebrospinal fluid (CSF) cell count, morphology and flow cytometric evaluations are used to investigate central nervous system (CNS) involvement in leukemia/lymphoma. We performed CSF short tandem repeat (STR) analysis to monitor CSF chimerism status and evaluate for disease involvement in 11 asymptomatic pediatric allogeneic hematopoietic stem cell transplantation (HSCT) recipients with hemato-lymphoid neoplasms and high risk for or history of CNS involvement. Eighteen (64%) of the samples with median CSF cell count of 1/mm³ with 90% lymphocytes gave conclusive STR results, suggesting that this DNA-based method can be used in monitoring CSF chimerism status after HSCT with an acceptable yield.