HLA Loci
KT
Key Takeaways
1.
Genetic Organization of HLA Loci
2.
Molecular Structures of Class I and Class II HLA
3.
HLA Antigen Expression and Definitions
4.
Private vs. Public Antigens in Transplant Immunology
5.
Shared Epitopes and Cross-Reactivity
6.
HLA Alleles and Nomenclature
Deceased Donor Allocation
National Framework: OPOs and UNOS/OPTN Roles
Donor Organ Quality and Scoring Systems
Allocation Process: Match Runs and Recipient Prioritization
Cold Ischemia Time and Organ Viability
Organ-Specific Allocation Policies and Recipient Selection
Key Allocation Challenges and Ongoing Innovations
Living Kidney Donors
Roles of UNOS and NKR in Facilitating Living Donor Transplants
Donor Chains and Paired Kidney Exchange Programs
Outcomes: Living Donor vs. Deceased Donor Kidney Transplants
Ethical Considerations in Living Donor Transplantation
Innovations in Paired Exchange Logistics and Matching
Recent Trends and Developments
Stem Cell Donors
Donor Registries and Sources of Stem Cell Donors (Role of NMDP and Others)
Mobilized Peripheral Blood vs. Bone Marrow Harvest (Collection Methods)
Related vs. Unrelated Donors (Including Haploidentical Donors)
HLA Typing and Donor Selection Criteria (Buccal Swabs and Matching)
Search and Allocation Process for Matching Donors
Ethical Considerations in Donor Selection
7.
Donor Eligibility Criteria and Evolving Trends in Selection
HLA Typing
PCR-SSP (Sequence-Specific Primers)
PCR-SSO (Sequence-Specific Oligonucleotide Probes)
Sanger Sequencing (SBT - Sequence-Based Typing)
Next-Generation Sequencing (NGS) – Short-Read vs Long-Read Technologies
Rapid HLA Typing for Deceased Donors: Nanopore Sequencing vs. Real-Time PCR
Antibody Testing
Overview of Anti-HLA Antibody Testing Methods
Luminex-Based Testing Methods
Flow-Based Assays (Flow Cytometry for HLA Antibody Detection)
False Positives and False Negatives in Antibody Assays
High Background Issues in Luminex Assays
Interpreting Luminex Data (MFI, Cutoffs, and Clinical Relevance)
Troubleshooting and Best Practices in HLA Antibody Testing
Crossmatch Testing
Introduction
Cell Types in HLA Crossmatch
Crossmatch Methods
Comparison of CDC vs. Flow Crossmatch
Interpretation of Results
Autocrossmatch
False Positives and False Negatives
8.
Common Assay Issues and Troubleshooting
9.
Recent Research and Best Practices
Crossmatch Interpretation
Crossmatch-Negative Scenario (Physical Crossmatch)
Crossmatch-Positive Scenario (Physical Crossmatch)
Virtual Crossmatch-Negative Scenario
Virtual Crossmatch-Positive Scenario
References
Chimerism Testing
1. Chimerism Testing Methods and Comparison
2. Role of Cell Subset Analysis in Chimerism Monitoring
3. Clinical Significance of Chimerism Results
4. Other Clinical Applications of Chimerism Analysis
5. Emerging Techniques and Future Trends
6. Guidelines and Best-Practice Recommendations
Disease Association Testing
HLA Loci, Antigens, and Alleles Tested
Clinical Guidelines and Indications
Comparison of Testing Methods
Platelet Transfusion Refractoriness
Causes of Refractoriness
HLA and HPA Antibodies in Refractoriness (Patient Risk Factors)
HLA Matching Considerations (HLA-A, B, and C) in Platelet Transfusion
Impact of ABO Matching on Platelet Transfusion Success
HLA Antibody Testing Methods: SSO, “Real-Time” Assays, and NGS
Calculated Panel Reactive Antibody (cPRA) and Its Role
Platelet Unit Selection Strategies for Alloimmune Refractoriness
Pooled Donor Platelets vs. HLA-Matched Platelets
Guidelines and Literature on Managing Platelet Transfusion Refractoriness
ABO Compatibility
Introduction to ABO Blood Group System
ABO Testing and Subtyping
Role of ABO Matching in Transplantation
ABO-Incompatible (ABOi) Transplants
A2 to B Transplants
Recent Studies and Guidelines
HLA Matching
Kidney Transplantation
Heart Transplantation
Lung Transplantation
Liver Transplantation
Hematopoietic Stem Cell Transplantation (Bone Marrow/Stem Cells)
Mean Fluorescence Intensity (MFI)
Typical MFI Cutoffs
Typical MFI Cutoff Ranges and Locus-Specific Cutoffs
Organ-Specific MFI Criteria (Kidney vs. Heart vs. Lung vs. Liver)
Clinical Outcomes and Transplant Success Relative to MFI
Virtual Crossmatch Interpretation Considerations
Conclusion
Decision Support Algorithms
When is Additional Testing Needed?
Resolving Discordant Crossmatch Results
Virtual Crossmatching in Imported or Urgent Organ Cases
Crossmatch Interpretation Decision Trees
Virtual Crossmatch and DSA Evaluations
DSA Risk Assessment by MFI Thresholds
Complement-Binding Assay Interpretations
IgG Subclasses and Their Implications
Technical Troubleshooting
Common Issues in HLA Testing and Their Solutions
Reflex Testing Algorithms for Ambiguous Cases
Regulations and Compliance
ASHI and OPTN/UNOS Requirements Overview
Required Testing by Transplant Scenario
Compliance Checklist for Transplant Evaluations
Cases
Quizzes
HLA Guide for Transplant Professionals
