Allogeneic hematopoietic stem cell transplant using mismatched/haploidentical donors

Area of Science:

• Hematology
• Immunology
• Transplantation Medicine

Background:

• Haploidentical hematopoietic stem cell transplantation (HSCT) is crucial for patients lacking human leukocyte antigen (HLA)-matched siblings.
• Early haploidentical HSCT faced high risks of graft-versus-host disease (GVHD) and infections, limiting its application.

Purpose of the Study:

• To review recent advancements in haploidentical HSCT.
• To identify persistent challenges and future directions for improving outcomes.

Main Methods:

• Effective T cell depletion strategies.
• Use of megadose stem cells.
• Reduced-intensity conditioning (RIC).
• Improved infection detection and antimicrobial therapy.
• Exploration of adoptive cellular immunity and selective allodepletion.
• Utilizing noninherited maternal antigen (NIMA)-mismatched or natural killer (NK) alloreactive donors.

Main Results:

• Significant reduction in early transplant-related mortality and GVHD.
• Prompt engraftment achieved.
• Persistent issues include delayed immune reconstitution, post-transplant infections, and disease relapse.
• Preliminary data suggests adoptive cellular strategies and specific donor types may enhance immune recovery without GVHD.

Conclusions:

• Haploidentical HSCT has evolved into a viable option due to technological and therapeutic advances.
• Addressing delayed immune reconstitution and relapse is critical for enhancing efficacy.
• Future research focuses on optimizing donor selection and transplant protocols to minimize GVHD while maximizing graft-versus-leukemia effects and immune recovery.