BMT Outcomes for Rare Pediatric Diseases at the Medical University of South Carolina

Background:  Rare diseases requiring hematopoietic stem cell transplantation present a challenge for pediatric BMT centers. The patients present at a low frequency, and there are often no established conditioning regimens for these disorders.  We report the conditioning regimen, donor source, and outcomes for the following rare disorders transplanted at our program from January 2011 through January 2014.  During the past three years we have had patients present with the following:  Fanconi anemia (FA), Hemophagocytic Lymphohistiocytosis (HLH), Congenital Amegakaryocytic Thrombocytopenia (CAMT), Chediak-Higashi Syndrome (CHS), Langerhans Cell Histiocytosis (LCH), Beta- thalassemia, Juvenile Myelomonocytic Leukemia (JMML), Immunodeficiency Syndrome with Myelodysplastic Syndrome (IDS/MDS), and Cartilage Hair Hypoplasia (CHH).

Methods:We are the sole pediatric HSCT center in our state.  We treat patients with rare disorders that require HSCT at our center, and are reporting the management strategy and outcomes for this wide variety of rare disorders.

Results:  The patients were referred to or diagnosed at our institution from January 2011 to January 2014.  All patients were transplanted with the best available donor using bone marrow (BM) or umbilical cord blood (UCB).  Conditioning regimens and treatment plans were determined by the BMT attending team based on reviews of the literature and varied with type of disease.  The BMT coordinators and nurse practitioners were educated about the disorders and then educated the inpatient and outpatient teams. The PharmD created order sets for patients based on the treatment plans. Patient characteristics and outcomes are presented in Table 1. The  day 100 survival was 100%.  Nine of 11 patients are alive and well (A/W) with no evidence of disease.

Table 1. Patient characteristics and outcomes for patients with rare disorders.

Patient	Disease	Donor /            HLA Match	Conditioning	ANC       > 500 (Day)	Platelet  > 20K (Day)	Outcome
1	HLH	UCB- 5/6	Bu/VP/CY/ATG	13	76	Died +1172
2	HLH	MSD BM- 10/10	Alem/Flu/Mel	9	34	A/W
3	FA	BM- 10/10	TBI/Flu/CY/ATG	14	29	A/W
4	B-thal	MRD BM- 8/10	Bu/CY/ATG	24	60	A/W
5	IDS/MDS	BM- 9/10	Bu/CY/ATG	15	19	A/W
6	LCH	MSD BM- 10/10	Alem/Flu/Mel	17	25	A/W
7	CHH	MSD UCB- 6/6	Bu/CY/ATG	16	25	A/W
8	JMML	MSD BM- 10/10	Bu/CY/Mel	19	69	A/W
9	CAMT	BM- 10/10	CY/ATG/TBI	15	15	A/W
10	HLH	BM- 9/10	Alem/Flu/Mel	9	15	Died +171
11	CHS	BM- 10/10	Bu/CY	21	33	A/W

Conclusions:  Our program has treated a variety of rare disorders with a > 80% Event-Free-Survival.  Our data suggests that excellent outcomes can be obtained at small-moderate sized BMT programs when the team approach is used to create the best-practices plan of care for each individual patient.