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.

Non-TBI hematopoietic stem cell transplantation in pediatric AML patients: a single-center experience.

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) has been established as a promising treatment in acute myeloid leukaemia (AML). Several studies have been performed to minimize the toxicity of HSCT in children without impairing the efficacy. We report our long-term results of HSCT in pediatric AML patients using non-total body irradiation conditioning regimen. PROCEDURE: From May 1991 to June 2010, 133 pediatric patients with AML (age<15 y) who were referred to our institute underwent autologous (auto-) or allogeneic (allo-) HSCT. The conditioning regimen consisted of oral busulfan plus etoposide in auto-HSCT patients and oral busulfan plus cyclophosphamide in allo-HSCT patients. RESULTS: Overall survival (OS), leukemia-free survival (LFS), probability of relapse, and transplantation-related mortality at 3 years were 67.6%, 62.2.5%, 27.3%, and 10.1%, respectively. There was no significant difference between allo-HSCT and auto-HSCT groups. In multivariable analysis using Cox proportional hazards regression model, male sex was associated with significantly improved OS (P<0.001) and LFS (P=0.022). An age ≤3 years was associated with higher relapse (P=0.034) and worse OS (P=0.001) and LFS (P=0.014). CONCLUSIONS: The role of allo-HSCT in pediatric AML patients in first complete remission is uncertain. Further randomized studies are recommended to clarify the optimal postremission therapy in these patients.

Relationship between endocrine changes and bone markers in pediatric thalassemic patients after hematopoietic stem cell transplantation.

BACKGROUND: Beta thalassemia major and its treatment by hematopoietic stem cell transplantation can have deleterious effects on bone integrity and a main part of such effects is due to their deleterious effects on endocrine systems. So, we assessed the effects of endocrine changes during HSCT (Hematopoietic Stem Cell Transplantation) on growing bones of pediatric thalassemic patients. METHODS: Bone-specific alkaline phosphatase and osteocalcin (bone formation markers), N-terminal telopeptide (NTX, bone resorption marker), calcium (Ca), phosphorus (P), alkaline phosphatase (Alk ph), parathyroid hormone (PTH), vitamin D (vit D), prolactin, luteinizing hormone (LH), follicle-stimulating hormone (FSH), thyroxine (T4), triiodothyronine (T3), thyroid-stimulating hormone (TSH), insulin-like growth factor 1 (IGF-1), testosterone (in males) or estradiol (in females), measured in 20 major thalassemic patients with mean age of 10.8±3.9 years. Parameters at the baseline (before HSCT), and 1 month and 3 months after HSCT. RESULTS: After stem cell transplantation, changes of mean serum levels of NTX, osteocalcin, prolactin, LH, T4, IGF-1, testosterone (in males), Ca, Alk ph, PTH, and vit D were not significant, but bone specific Alk ph, P, T3, TSH, FSH and estradiol changed significantly (P=0.013, P=0.001, P=0.48, P=0.02, P=0.04 and P=0.001, respectively). After one month, there was a significant positive relationship between osteocalcine and T3 (p= 0.009). After 3 months, also, there was a significant positive relationship between osteocalcine and T3 and T4 as well as a negative one with IGF-1 (P<0.001, P<0.02 and P<0.03, respectively). CONCLUSIONS: Endocrine disorders do not appear to have an overall positive or negative effect on bone metabolism (anabolism or catabolism) in HSCT pediatric thalassemic patients in short term (three months).

A Novel Mutation in SNX10 Gene Causes Malignant Infantile Osteopetrosis.

BACKGROUND: Osteopetrosis is a group of genetically heterogonous diseases and the main feature of that is increased bone density due to osteoclast's abnormality. It has three clinical forms based on inheritance pattern, severity and age of onset: the dominant benign form (ADO), the intermediate form (IRO) and the recessive severe form (ARO). One of the recently discovered genes for ARO form is SNX10 that accounts for 4% of affected persons by this type. METHODS: In this paper, a 15 years old girl affected by osteopetrosis has been analyzed for detecting causal mutation in known osteopetrosis genes. To get it done, amplified exons of the genes were sequenced and then were analyzed. RESULTS: Direct sequencing of SNX10 gene showed a homozygous c.43delG variant in the patient. Both healthy parents were heterozygous for this variant. In silico analysis revealed that this novel variant can be considered as the cause of disease in the patient. CONCLUSION: In this paper, a girl affected by osteopetrosis with a novel deletion in SNX10 gene was reported.