HLA Compatibility & Dual-Transplant Chimerism Engine

Clinical Immunology Simulation
Clinical Presenarios:

HLA Allele Inheritance

5 / 10 Match

Comparison of HLA Class I (A, B, C) and Class II (DRB1, DQB1) loci between Donor (Son) and Recipient (Father).

Locus Donor Allele Recipient Allele Match
Donor Chimerism Level 98.5%
Recipient Cell Conditioning (Ablation) 95.0%

Bone Marrow Stem Cell Microenvironment

Full Donor Chimerism
Donor HSC / T-Cells
Recipient HSC / Lymphoma
Thymic Epithelial Cell
GvHD Risk 18% Mild / Tolerable
GvL Effect 88% Strong Lymphoma Elimination
Thymic Tolerance 94% Central Deletion Active
Kidney Rejection Risk 2.1% Rejection-Free Tolerance

Thymic Central Tolerance Induction

Developing T-cells undergo negative selection in recipient thymus. High donor chimerism trains new T-cells to recognize donor kidney antigen as self.

Immunological Mechanism

By achieving >95% donor hematopoietic stem cell chimerism, donor-derived dendritic cells repopulate the recipient thymus. Developing T-lymphocytes reactive to donor HLA antigens are deleted (negative selection), establishing permanent donor-specific immune tolerance.

Sequential Dual-Transplant Clinical Timeline

Sequential Case Study
1
2013: Diagnosis
2
Stem Cell BMT
3
Full Chimerism
4
Kidney Donation
Stage 2: Bone Marrow Transplantation (Haploidentical)
David undergoes conditioning followed by hematopoietic stem cell infusion from his son. Donor HSCs engraft in the recipient marrow microenvironment, establishing mixed and eventually full donor chimerism.