A case of chronic myelomonocytic leukaemia and factor XI deficiency with a circulating anticoagulant

Abstract

Inhibitors against factor XI (FXI) have been frequently described in patients who acquired inhibitors (due to auto-immune disorders, malignancies or infections), but less often in those with a congenital deficiency of this factor, who had received plasma infusions. The present report concerns one such inhibitor found in the plasma of a patient with chronic myelomonocytic leukaemia and infected by B19 parvovirus, who was neither a heterozygote nor a homozygote for FXI deficiency, and who had no bleeding tendency despite a very low FXI level. Taking this case into account, we discuss and present the clinical and biological features of acquired FXI deficiency caused by an inhibitor.

Acquired Factor XI Inhibitor Presenting as Spontaneous Bilateral Subdural Hematoma in an Elderly Patient

“…Bleeding symptoms of acquired FXI deficiency are poorly related to residual FXI activity [1] and include mild or absent bleeding [4, 6, 7], mucocutaneous bleeding [8], postsurgical hemorrhage [5, 10], and life-threatening [11] or fatal intracranial bleeding, as here reported. Unlike AHA, soft tissue and deep muscle bleeding are uncommon in acquired FXI deficiency [2].…”

“…Acquired FXI inhibitors in patients without congenital FXI deficiency have been associated with systemic lupus erythematosus (SLE) [8, 11], hematopoietic malignancies [5, 6, 9], solid cancer [7], inflammatory bowel disease [7], chlorpromazine-treatment [4], and pelvic surgery [10]. Patients usually present with isolated prolonged aPTT not corrected by mixing with normal plasma [1, 2].…”

“…Unlike AHA, there is no consensus on the optimal treatment of acquired FXI inhibitors [1] and most data are derived from treatment of patients with congenital FXI deficiency, with or without secondary inhibitors [19]. Proposed treatment includes (a) antifibrinolytic agents [10, 19], aPCC [20], or rFVIIa [15] for arresting the bleeding, (b) corticosteroids [4, 5, 7–9, 11, 12], azathioprine [6, 8, 11], intravenous immunoglobulins [6, 21], plasma-exchange [21], or rituximab [8] for inhibitor eradication, and (c) specific treatment of the underlying immunologic disorder [5, 8]. In the present report, no hemostatic therapy was administered because of unavailability of coagulation tests, severe disability, and rapid clinical deterioration and death.…”