Successful allogeneic stem cell transplantation with a reduced-intensity conditioning in a leukocyte adhesion deficiency type I patient

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.

Long-term outcomes of fludarabine, melphalan and antithymocyte globulin as reduced-intensity conditioning regimen for allogeneic hematopoietic stem cell transplantation in children with primary immunodeficiency disorders: a prospective single center study

Reduced-intensity conditioning (RIC) has offered many primary immunodeficiency disorder (PID) patients who are ineligible for myeloablative regimens a chance of cure. However, the beneficial role of RIC was questioned following reports suggesting higher chance of rejection and lower symptom resolution rate in mixed chimerism settings. Forty-five children affected by PIDs with a median age of 21 months underwent allogeneic hematopoietic stem cell transplantation in our institute from 2007 to 2013. All patients received an identical RIC regimen. Forty-one patients had successful primary engraftment (91%). Of the successful engraftments, 80% (n=33) had stable full donor chimerism at last contact. Overall, eleven transplant-related mortalities were reported including five patients due to sepsis, three children due to grade IV acute GvHD, two due to chronic GvHD and one patient due to sepsis after primary graft failure. The median post-transplantation follow-up of deceased patients was 55 days. Five-year overall survival and disease-free survival was 75.6% and 68.89%, respectively. All surviving patients with successful engraftment became disease free, regardless of having full or mixed chimerism. Our study suggests that RIC regimen provides satisfactory rates of successful engraftment and full chimerism. Furthermore, patients with mixed chimerism were stable in long-term follow-up and this chimerism status offered the potential to resolve symptoms of immunodeficiency.