Monoclonal gammopathy of thrombotic significance

Monoclonal gammopathy of thrombotic significance (MGTS) is a prothrombotic condition caused by monoclonal antibodies against Platelet factor 4 (anti-PF4) that presents with recurrent thrombosis and persistent thrombocytopenia.^[1]^[2]

There are currently three types of MGTS:

vaccine-induced immune thrombotic thrombocytopenia (VITT) VITT-like MGTS
Heparin-induced thrombocytopenia (HIT) HIT-like MGTS
MGTS that is neither HIT-like nor VITT-like

References

^ Kanack, Adam J.; Shah, Surbhi; Padmanabhan, Anand (1 March 2025). "Investigation of Patient With Monoclonal Gammopathy of Thrombotic Significance Unmasks New Type of Platelet-Activating Anti-Platelet Factor 4 Antibody". The Hematologist. 22 (2). doi:10.1182/hem.V22.2.2025213.
^ Today, Cap (19 June 2025). "Spectrum of anti-PF4 disorders widens - CAP TODAY". www.captodayonline.com. Retrieved 22 June 2025.

Disorders of bleeding and clotting

Clotting

By cause	Clotting factors Antithrombin III deficiency Protein C deficiency Activated protein C resistance Protein S deficiency Factor V Leiden Prothrombin G20210A Platelets Sticky platelet syndrome Thrombocytosis Essential thrombocythaemia DIC Purpura fulminans Antiphospholipid syndrome
Clots	Thrombophilia Thrombus Thrombosis Virchow's triad Trousseau sign of malignancy
By site	Deep vein thrombosis Bancroft's sign Homans sign Lisker's sign Louvel's sign Lowenberg's sign Peabody's sign Pratt's sign Rose's sign Pulmonary embolism Renal vein thrombosis

Bleeding

By cause

Thrombocytopenia	Thrombocytopenic purpura: ITP Evans syndrome TM TTP Upshaw–Schulman syndrome Heparin-induced thrombocytopenia (HIT) May–Hegglin anomaly (MGTS)
Platelet function	adhesion Bernard–Soulier syndrome aggregation Glanzmann's thrombasthenia platelet storage pool deficiency Hermansky–Pudlak syndrome Gray platelet syndrome
Clotting factor	Haemophilia A/VIII B/IX C/XI von Willebrand disease Hypoprothrombinemia/II Factor VII deficiency Factor X deficiency Factor XII deficiency Factor XIII deficiency Dysfibrinogenemia Congenital afibrinogenemia

Signs and symptoms

By site