Three cases of neutralization of factor Xa inhibitors with andexanet alfa under rotational thromboelastography monitoring.

Background: Factor Xa inhibitors are direct oral anticoagulants that are extremely useful in clinical applications, safe, and do not require dose adjustment. It is desirable to be able to monitor their effects in the event of hemorrhagic complications requiring neutralization. However, it is difficult to monitor their activity and neutralization using conventional coagulation tests. Case Presentation: We report three patients taking factor Xa inhibitors who underwent rotational thromboelastography (ROTEM) monitoring before and after neutralization with andexanet alfa. All three patients had hemorrhagic complications that required neutralization of their factor Xa inhibitors using andexanet alfa. One ROTEM parameter, the EXTEM clotting time (EXTEM-CT), was immediately shortened after andexanet alfa bolus administration, without subsequent extension of the EXTEM-CT assessed 4 h after the bolus dose. Conclusion: ROTEM parameters, particularly EXTEM-CT, might be useful for monitoring neutralization of factor Xa inhibitors.

[Atezolizumab-induced Guillain-Barré syndrome-like acute demyelinating polyneuropathy responsive to steroid therapy: a case report].

A 76-year-old man, who received atezolizumab for the treatment for small cell lung cancer, acutely developed limb weakness with sensory disturbance after the third course of the treatment. Nerve conduction studies were consistent with demyelinating polyneuropathy and acute demyelinating polyneuropathy caused by atezolizumab was suggested. Atezolizumab was immediately withdrawn, and intravenous immunoglobulin (IVIg) and methylprednisolone pulse therapies with subsequent oral administration of prednisolone were initiated, after which neurological deficits steadily improved. Although Guillain-Barré syndrome-like neuropathy caused by immune checkpoint inhibitor (ICI) was occasionally reported, this is the first case of acute demyelinating polyneuropathy triggered by atezolizumab, monoclonal antibody targeting programmed death-ligand 1. This case suggests that combined treatments with IVIg and corticosteroids are effective for neuropathy induced by atezolizumab as same as those by other ICI.

[A 81-year old man of anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase antibody-positive myopathy associated with lung adenocarcinoma cancer].

An 81-year-old man, who had no history of taking statins, developed progressive muscle weakness of the limbs and dysphagia. Laboratory tests showed a high level of CK and positivity for serum 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) antibodies. Tests for other autoantibodies to ARS and SRP were negative. A pathological analysis of the left biceps muscle revealed numerous necrotic and regenerated fibers with macrophage infiltration and deposition of C5b-9 complement in and around the myofibers. Chest CT showed a nodular shadow, which was suspected to be lung cancer, in the upper left lobe. A pathological analysis of a transbronchial lung biopsy specimen revealed lung adenocarcinoma with high level of HMGCR. He was diagnosed with HMGCR necrotizing myopathy associated with lung cancer, and both his muscle strength and dysphagia improved after three treatments with intravenous immunoglobulin (IVIg). He did not undergo surgery or radiation therapy because of interstitial pneumonia. This case suggests that a paraneoplastic mechanism caused the production of HMGCR antibodies, leading to myositis in this patient. Treatment with IVIg can be effective for patients with HMGCR antibody-positive paraneoplastic necrotizing myopathy that is refractory to corticosteroid therapy.