Fludarabine-based Reduced Intensity Conditioning for Allogeneic Hematopoietic Stem Cell Transplantation in a Pediatric Patient With Bone Marrow Failure Syndrome Type 3

Bone marrow failure syndrome (BMFS) type 3 is a rare genetic heterogeneous disorder, considered to be one of Inherited BMFSs related to ribosomopathies. It caused by a novel Homozygous variant in DNAJC21 gene, which affects cytoplasmic maturation of 60S ribosomal, leading to increase cell death, and inhibits cellular proliferation causing shwachman-diamond Syndrome-like syndrome. Only 15 cases of BMFS type 3 have been published in the literature. Therefore, the full phenotypic spectrum and the experience of hematopoietic stem cell transplantation (HSCT) are limited. Herein, we report an uncomplicated HSCT from human leukocyte antigen-identical sibling for a BMFS-3 patient at 22 months of age, who suffered from chronic diarrhea, severe failure to thrive and cytopenia required transfusions. We used a reduced intensity conditioning regimen including fludarabine, low-dose cyclophosphamide, and antithymocyte globulin with cyclosporine for prevent graft versus host disease. This regimen was safe and sufficient to achieve rapid engraftment without significant toxicity. Although, Mixed chimerism between 80% and 90% was observed since day +30, she gained 2 kg during 12 months post-transplant and no need for transfusions has been reported any more. Thus, we recommend HSCT with fludarabine-based reduced intensity conditioning regimen in this syndrome as progressive cytopenia occurs and an human leukocyte antigen-matched family donor is available.

Successful allogeneic stem cell transplantation with fludarabine-based reduced intensity conditioning in bone marrow failure syndrome 4

BACKGROUND

Myb-like, SWIRM, and MPN domains 1 (MYSM1) is a histone H2A deubiquitinase, has been discovered as one of the transcriptional regulators, and regulates the expression of specific transcription factors, which are essential for immunohematology development. Mutation in MYSM1 in humans leads to a rare autosomal recessive disease that has recently been known as inherited bone marrow failure syndrome 4 (BMFS4) associated with congenital bone marrow failure, immunodeficiency, and developmental aberrations. Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative option for immunohematology defects.

METHODS

In this paper, we report a pediatric patient with BMFS4 who suffered from pancytopenia and immunodeficiency affecting B cells and was successfully treated with HSCT from an HLA-identical father at 6 years old of age. Fludarabine-based reduced intensity conditioning was used and resulted in full donor chimerism.

RESULTS

Acute graft versus host disease (GVHD) grade II involving skin and gastrointestinal tract was observed, which was controlled with prednisolone.

CONCLUSION

She achieved B-cell recovery, and no blood or platelet transfusion was reported 1 year after HSCT.

Posterior Reversible Encephalopathy Syndrome after Allogeneic Stem Cell Transplantation in Pediatric Patients with Fanconi Anemia, a Prospective Study

Posterior reversible encephalopathy syndrome (PRES) is one of the most common neurologic complications following hematopoietic stem cell transplantation (HSCT). We aimed to evaluate the incidence, clinical, and imaging features of PRES in pediatric patients with Fanconi anemia (FA) following HSCT. This prospective study included all post-HSCT patients with underlying FA disease between 2014 and 2017. Brain computed tomography scan and magnetic resonance imaging (MRI) were performed in all individuals who developed neurologic symptoms. PRES was diagnosed based on clinic-radiological evidence. Follow-up MRI was performed in all patients with PRES within two months. Forty-one patients with FA (28 males; mean age, 8.19 ± 3.25 years) were enrolled. Out of 15 patients with acute neurologic symptoms, PRES was diagnosed in 9 individuals (21.95% of the total cohort). The occurrence of PRES was significantly higher in patients who had a donor with a 1-locus mismatch (P= .02). Donor relation, stem cell source, and graft-versus-host disease grade did not have any significant association with the development of PRES. MRI showed asymmetric vasogenic edema in 5 patients, an overt infarct in 1 patient, and foci of microhemorrhages in 3 patients, 1 of whom developed a hemorrhagic infarct. This patient died shortly, and persistent microhemorrhages were noted in the other 2 patients. Our findings demonstrate a greater risk of developing PRES after HSCT in patients with FA compared with those with other diseases (21.95% versus 1% to 10%), and in contrast to its term, it might be irreversible and has adverse effects on HSCT outcomes. The increased vascular and endothelial fragility in FA may contribute to the higher frequency of PRES in these individuals.

The treatment of children suffering from chronic myelogenous leukemia: a comparison of the result of treatment with imatinib mesylate and allogeneic hematopoietic stem cell transplantation

HSCT is the only proven treatment option for CML, a rare disease in children. Recently, there are promising reports on the advantageous effect of imatinib mesylate for pediatric patients with CML. We conducted a retrospective study on 33 pediatric patients suffering from CML. Fourteen underwent HSCT and the rest were treated with imatinib. With a median follow-up of 24 months, the two-yr OS in the HSCT group and the imatinib group was 84% and 87%, respectively (p = 0.714). The probabilities of two-yr DFS were 59% in the HSCT group and 82% in the imatinib group, either (p = 0.880). Relapse occurred in 5 (35.7%) patients of the HSCT group, and 8 (42.1%) patients showed relapse in the imatinib group. Among nine patients who died, five were in the HSCT group and the rest were in the imatinib group. The probability of relapse in the patients of the imatinib group followed up for several consecutive years may be higher than observed in the HSCT group, so we cannot easily conclude which way is more reliable.