No abstract

Factor XI plays a pivotal role in the intrinsic pathway of coagulation. It aids in thrombin generation, coagulation cascade propagation, and down-regulation of fibrinolysis. [1] The role of factor XI in inflammation and malignancies is an ongoing area of research with a potential impact on thromboprophylaxis and sepsis. [2,3] Deficiency of Factor XI, also known as hemophilia C, is a rare bleeding disorder with a global incidence of 1/1 million. [2,4] It can be genetic, inherited as an autosomal recessive disease, or rarely acquired due to inhibitors. Most of these inhibitors are antibodies, which partially or completely neutralize the clotting factor. [3] Spontaneous bleeding in an isolated factor XI deficiency is not very common, and the patient may remain asymptomatic for years, suddenly presenting with unexplained bleeding or elevated activated partial thromboplastin time (APTT). [5] In most patients, bleeding episodes occur after surgery, dental procedures, or trauma. [2] An APTT mixing study after incubating patient plasma with pooled normal plasma differentiates genetic factor deficiency from acquired factor deficiency due to inhibitors.Here, the authors present the two cases of Factor XI deficiency, one inherited and the other acquired, illustrating the importance of a complete coagulation workup for an elevated coagulation screening test. The first case is from an obstetric setup, and to the best of our knowledge, it is the second case of Factor XI deficiency in pregnant women reported in the literature from India