Antonio Paul on Blame Game in Transplantation: HLA vs Microbes
Antonio Paul, Head of ACTIMoS- Advanced Center for Transplant Immunology and Molecular Science, shared on LinkedIn:
”Blame Game in Transplantation: HLA vs Microbes
What if HLA antibodies are not always about HLA?
For decades, we’ve taught that anti-HLA antibodies arise from the usual suspects:
- Prior transplants
- Blood transfusions
- Pregnancy
But many patients develop de novo anti-HLA antibodies without any classic sensitization history.
Growing evidence suggests another culprit: Infections.
What’s happening?
Microbes can trigger HLA antibodies through several mechanisms:
- Molecular mimicry – Microbial antigens may resemble HLA epitopes, leading to cross-reactive antibodies.
- Innate immune “danger signals” – Toll-like receptor activation can break immune tolerance and promote rejection.
- Bystander B-cell activation – Cytokine surges during infection can awaken dormant HLA-reactive memory B cells.
- Polyclonal immune activation – Broad antibody expansion may occur after infections or vaccinations.
Clinical evidence shows that infections often precede:
– Increased panel reactive antibodies (PRA)
– Emergence of donor-specific antibodies (DSA)
– Higher rejection risk
– Poorer graft survival
Rethinking an old assumption
Not all HLA antibodies are born from mismatched HLA.
Some may be born from mismatched microbes.
Transplant success may depend not only on how well donors and recipients are matched, but also on which microbes the immune system remembers.”

Stay updated with Hemostasis Today.
-
Aug 14, 2026, 08:17Maha Othman: Celebrating Research and Collaboration at the Sinclair Cancer Research Institute 2026 Annual Retreat
-
Aug 14, 2026, 06:26Delivering Gene Therapy in Hemophilia – ISTH
-
Aug 13, 2026, 18:39Lukas Röthlisberger: Real-World Evidence on Effectiveness and Safety of Rivaroxaban in Children
-
Aug 13, 2026, 18:36Soner Yilmaz: Blood Safety in Türkiye Through More Than 22.5 Million Blood Donations
-
Aug 13, 2026, 18:31Muthukumarasamy Raja: FDA Approval of EZPLAZ Marks a Breakthrough in Emergency Plasma Care
-
Aug 13, 2026, 18:29Peter Zdziarski: Protecting Our Community While Creating a Future Where We Are No Longer Needed
-
Aug 13, 2026, 18:29Morgan E Amos: Thrilled to Receive the Student Research Award From HTRS
-
Aug 13, 2026, 16:38Sheharyar Raza: Plasma Exchange in Multiple Sclerosis
-
Aug 13, 2026, 16:31Juan Manuel Cisneros Carrasco: The True Cost of Blood Donation