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.
-
May 12, 2026, 16:46Tagreed Alkaltham: Why Apheresis Matters in Modern Transfusion Medicine
-
May 12, 2026, 16:37Reinhold Kreutz: Cardiovascular Burden in Acute Intermittent Porphyria Needs Greater Awareness
-
May 12, 2026, 16:33Pablo Corral: The Truth About Very Low LDL-Cholesterol
-
May 12, 2026, 16:24Mildred Lundgren: We Must Talk About the Invisible Causes of Stroke
-
May 12, 2026, 16:17Irene Scala: The Sex Disparities In Access to Acute Stroke Treatments In Italy
-
May 12, 2026, 16:04May Nour: UCLA Health Mobile Stroke Unit Becomes The 1st In The World to Perform mCTA In the Field
-
May 12, 2026, 15:57Leonardo Roever: Prognostic Impact of Lipoprotein(a) and CAR in Elderly Acute Ischemic Stroke Patients
-
May 12, 2026, 15:54Bruno Pougault: Prioritizing Laboratory Tests in Resource-Limited Emergency Care
-
May 12, 2026, 15:37Jennifer Holter Chakrabarty: Supporting the Next Generation of Hematology Researchers