Background and Aims

There are limited data in second HSCT outcomes in PID. Conditioning regimen, stem cell source and GVHD prophylaxis (either with graft processing, or immunosuppression) are serious issues to consider before re-transplantation following severe graft failure (GF). We share our experience of second HSCT in PID patients.

Methods

Between 2012 and 2018 238 patients with various PID underwent HSCT in our center. 34 patients developed GF (non-engraftment, n=5; graft rejection, n=29) after HSCT from MUD (n=22), MRD (n=2) and MMRD (n=10); graft rejection occurred within 1,0-14,7 months (median 3,1).

Second HSCT was performed in 31 patients in 2,1-23,0 months (median 6) after first HSCT. The source of stem cells was PB (n=23) or BM (n=8) from MUD (n=21) or MMRD (n =10). 12 patients received predominantly immunoablative conditioning with TLI, fludarabin, cyclophosphamide and melphalan, 19 - different treosulfan/busulfan based myeloablative regimens. All but one patients received serotherapy. TCRab+/CD19+ graft depletion was performed in 23 cases, 8 patients had non-manipulated graft; 5 of them with posttransplant cyclophosphamide d+3,+4.

Results

Acute GVHD grade II-IV was observed in 3 patients, GF in 7. Overall survival was 66%+8,8. Causes of death were bacterial sepsis (n=5), viral infections (n=2), cGVHD (n=1), TMA/MOF (n=2). Immuno- or myeloablative conditioning did not influence HSCT outcomes.

Conclusions

Second HSCT after severe GF is a feasible option for PID patients. Infections are still the leading cause of TRM. Patient’s clinical status, time and type of GF after first HSCT has to be considered for individualized conditioning regimen and GVHD prophylaxis strategy.