Longevity & AgingAnti-PF4 Disorders: How Rogue Antibodies Drive Dangerous Blood Clots
Platelet factor 4 (PF4) is a cationic protein released from platelets that can form complexes with negatively charged molecules. When IgG antibodies target these complexes, the result is uncontrolled platelet, neutrophil, and monocyte activation — driving thrombocytopenia and dangerous clotting. This 2025 review from Imperial College London covers the full spectrum of anti-PF4 disorders: classic heparin-induced thrombocytopenia (HIT), autoimmune HIT variants, vaccine-induced immune thrombocytopenia and thrombosis (VITT) following SARS-CoV-2 vaccination, and newly recognized VITT-like syndromes occurring without heparin or vaccination. The review details pathogenesis, diagnostic strategies, and tailored treatment approaches across patient groups.
