Young adults with primary immunodeficiencies (PIDs) undergoing allogeneic hematopoietic cell transplantation (HCT) can achieve a 3-year overall survival greater than 80%, according to a study of 29 consecutive young adults transplanted at two U.K. hospitals.
The patients had a mean age at transplant of 24 years (range, 17-50), and underwent reduced-intensity conditioning HCT using matched or mismatched unrelated donors (n=18) and matched related donors (n=11).
Patients had not previously been considered for HCT for a variety of reasons, but developed complications requiring definitive treatment. Factors triggering HCT referral included life-threatening infection, malignancy, autoimmune or inflammatory phenomena, and new donor availability. Use of next-generation sequencing is expected to confirm genetic diagnoses of PIDs, which will facilitate early referral of eligible adults.
Overall survival (OS) in all patients at three years post-transplant was 85.2%. Three-year OS was highest (at 88.9%) in the 18 patients who did not have chronic granulomatous disease (CGD), compared with 81.8% for the 11 patients with CGD.
Transplant-related mortality was low with only 4 deaths observed at a median follow-up of 3.5 years. All surviving patients achieved either stable mixed chimerism or full donor chimerism. At last follow-up, 87% of the surviving patients had no evidence of persistent or recurrent infections.
In a Blood commentary on the research, Dr. Blachy Saldaña noted that despite the heterogeneity of the patient cohort, “survival outcomes are impressively good, with resolution of most clinical indicators for transplant despite instances of mixed chimerism.”
The researchers concluded that “allogeneic HCT is safe and effective in young adult patients with severe PID and should be considered the treatment of choice where an appropriate donor is available.”