Utility of Plasmapheresis in Autoimmune-Mediated Encephalopathy in Children: Potentials and Challenges

Undercover lung damage in pediatrics - a hot spot in morbidity caused by collagenoses

Connective tissue represents the support matrix and the connection between tissues and organs. In its composition, collagen, the major structural protein, is the main component of the skin, bones, tendons and ligaments. Especially at the pediatric age, its damage in the context of pathologies such as systemic lupus erythematosus, scleroderma or dermatomyositis can have a significant negative impact on the development and optimal functioning of the body. The consequences can extend to various structures (e.g., joints, skin, eyes, lungs, heart, kidneys). Of these, we retain and reveal later in our manuscript, mainly the respiratory involvement. Manifested in various forms that can damage the chest wall, pleura, interstitium or vascularization, lung damage in pediatric systemic inflammatory diseases is underdeveloped in the literature compared to that described in adults. Under the threat of severe evolution, sometimes rapidly progressive and leading to death, it is necessary to increase the popularization of information aimed at physiopathological triggering and maintenance mechanisms, diagnostic means, and therapeutic directions among medical specialists. In addition, we emphasize the need for interdisciplinary collaboration, especially between pediatricians, rheumatologists, infectious disease specialists, pulmonologists, and immunologists. Through our narrative review we aimed to bring up to date, in a concise and easy to assimilate, general principles regarding the pulmonary impact of collagenoses using the most recent articles published in international libraries, duplicated by previous articles, of reference for the targeted pathologies.

Effect of Plasmapheresis on the Anti-Factor Xa Activity of Enoxaparin in an Obese Adolescent Patient

To our knowledge, the effect of plasmapheresis on the anti-factor Xa activity of enoxaparin has never been reported. We describe a 13-year-old, obese (92-kg) girl who was treated with enoxaparin for a pulmonary embolism while receiving plasmapheresis for suspected autoimmune encephalitis and who experienced clinically significant reductions in anti-factor Xa activity after plasmapheresis. She received five courses of plasmapheresis, with the final two administered during treatment with enoxaparin. Her anti-factor Xa concentrations were highly variable, and we hypothesized that plasmapheresis was affecting these levels. To test this hypothesis, anti-factor Xa concentrations were measured before and immediately after the patient's last plasmapheresis treatment, and then again 2 days after plasmapheresis. The rate of anti-factor Xa activity decline was 0.28 IU/mL/hour with plasmapheresis and only 0.088 IU/mL/hour on the day without plasmapheresis, representing a greater than 3-fold difference. The changes in anti-factor Xa activity due to plasmapheresis altered the final enoxaparin dosage required to remain in the therapeutic range of 0.5-1 IU/mL (0.98 mg/kg/dose while receiving plasmapheresis vs 0.69 mg/kg/dose without plasmapheresis). Our patient's data suggest that plasmapheresis can significantly alter enoxaparin's anticoagulant effect as measured by anti-factor Xa concentrations, which could cause a decreased anticoagulant effect during plasmapheresis and an increased risk of bleeding on plasmapheresis discontinuation. If concurrent enoxaparin-based anticoagulation and plasmapheresis are necessary, close monitoring of anti-factor Xa levels is advisable. Dose escalations and reductions of enoxaparin may be necessary when initiating and discontinuing plasmapheresis, respectively.