Older people with CHIP are safe donor source for HSCT

The researchers noted that no other CHIP mutations or characteristics affected the development of chronic GVHD.

Donor CHIP status did not impact the incidence of acute GVHD or CMV reactivation.

Transplant recipients with CHIP donors had a lower CIR/P (P=0.027) than recipients with non-CHIP donors. Patients whose donors had CHIP with a DNMT3A mutation also had a lower CIR/P (P=0.029).

Donor CHIP had no effect on NRM.

Neither donor CHIP nor donor DNMT3A mutational status impacted CIR/P or NRM in patients who underwent HSCT while they were in complete response (CR).

However, patients not in CR at the time of HSCT had a lower CIR/P when the donor was CHIP-positive (hazard ratio [HR]=0.49; 95% confidence interval [CI], 0.27 to 0.88; P=0.019) or had a DNMT3A mutation (HR=0.34; 95% CI, 0.15 to 0.81; P=0.015).

Two of 82 patients with CHIP donors developed donor-cell malignancies, but there were no donor-cell malignancies in recipients with non-CHIP donors (P=0.026).

Survival

“To our knowledge, we showed, for the first time, that donor CHIP did not affect the survival of 500 HSCT recipients,” the researchers wrote.

At a median follow-up of 3.3 years, the median OS was 2 years, and the 5-year OS was 37.6%.

The researchers observed no survival differences in patients with CHIP donors or non-CHIP donors (HR=0.88; 95% CI, 0.65 to 1.321; P=0.434). And the same was true for DNMT3A mutation (HR=0.89; 95% CI, 0.58 to 1.35; P=0.573).

The researchers pointed out that patients with myelodysplastic syndromes or acute myeloid leukemia who were not in CR when they underwent HSCT had a survival benefit with donor CHIP (HR=0.49; 95% CI, 0.28 to 0.86; P=0.011).

“This finding could implicate an important clinical potential in this difficult-to-treat subgroup,” the researchers noted.

However, this was not the case for patients with myeloproliferative neoplasia, for whom donor CHIP tended to reduce survival (P=0.077).

The research team recommended future studies be conducted in younger and unrelated donors to confirm the results of this study.

The research was funded by numerous grants and fellowships, and the researchers reported no relevant conflicts of interest.