A preliminary study on the effects of feto-maternal microchimerism in activated human leukocyte antigen haploidentical mobilized peripheral blood stem cells on treatment of solid tumors / 中华内科杂志

ABSTRACT

Objective To study the effect of feto-matemal microchimerism in the treatment of activated human leukocyte antigen (HLA) haploidentical mobilized peripheral blood cells against solid tumors. Methods Genomic DNA samples of 25 pairs of HLA haploidentical donors and recipients were extracted. The donor-derived HLA-DRB loci were detected with nested PCR-sequence specific primer(SSP) typing. The mixed lymphocyte proliferation action between the patients and respective donors, the engraftment of donor's cells and the serum levels of Th1/Th2 type of cytokines were measured with MTT,FISH and EIJSA method respectively. The survival time of patients with or without feto-matemal microchimerism were compared as well. Results Using nested PCR-SSP typing, the positive rates of feto-maternal microchimerism in the 25 pairs of HLA haploidentical donors and recipients were 40% in the maternal/children pairs and 0 in the paternal/children pairs. The chimerism positive patients showed less proliferation activity when cocultured with respective donors as compared with unrelated ones (P=0.03).Only one chimerism positive patient experienced the engraft of donor's cell 3 months after treatment as the donor derived XX chromosome was identified with FISH. When the data of chimerism positive patients were deleted, the serum levels of IFNγ 1 month after treatment dropped dramatically from 171.4 (26. 3～258.4) ng/L to 29. 4(1.2～39.9)ng/L. The survival time in chimerism positive patients of the maternal/children pairs was significantly longer than that in chimerism negative patients, which was (31.2±4. 3) months and (11.1±3.3) months, respectively (P=0.036). Conclusion Feto-maternal microchimerism might induce anergy in the HLA haploidentical donors, favor the engraftment of donor's progenitors and maintenance of positive microenvironment and prolong the survival time.