Background and Aims

Haematopoietic cell transplantation (HCT) is the only curative therapy for MHC class II expression deficiency.

Methods

We examined the outcome of 25 children with MHC class II deficiency who received a HCT at the Great North Children’s Hospital between 1995 and 2018. Outcomes included overall survival (OS), toxicity and long-term outcome. Log rank test was used to analyse predictors of OS.

Results

Median age of transplant was 21.4 months (range, 0.9-93.3). The 3-year OS for the entire cohort was 78%, increasing to 94% for HCT after 2008 (n=19) vs 33% for HCT before 2008 (n=6) (Figure1). After 2008, the OS was comparable between matched family (100%), unrelated (100%) and parental haploidentical donor recipients (85%) (Figure2). Three had graft failure and received a second transplant but died. 9 patients had grade 1 acute GvHD (36%), 4 (14%) grade II, none grade III-IV and none had chronic GvHD.

Of 14 long-term survivors with evaluable data, the median age at last follow-up was 5.2 years (range, 2.2 to 14) with the median duration of follow-up 3.5 years (range, 1.1 to 7.2). All were off immunoglobulin. Median myeloid chimerism was 100% (range, 0-100) and median T-lymphocyte chimerism was 100 (range, 59-100). The median CD count was 754 x109/L (range, 201 to 1900). 4 had CD4 lymphopenia.

Conclusions

Transplant survival has improved and long-term disease outcome of survivors is good.