P35 Adopting a personalized approach to blood monitoring in patients with psoriasis-prescribed biological therapy: a retrospective single-centre review of real-world data
Authors: Hussain Amaani B , Singleton Grace , Ball Stephanie , Weatherhead Sophie , Reynolds Nick J , Hampton Philip 
Published: June 2023

Six-monthly blood monitoring is performed for patients with psoriasis-prescribed biological drugs at most UK centres. This has significant healthcare cost implications, creates a burden on patient time and has a considerable environmental impact. We aimed to investigate blood abnormalities in patients prescribed biologics in our centre, to determine whether the monitoring frequency could be reduced. We reviewed the records of patients with psoriasis prescribed a biologic drug who attended the clinic between September and October 2022 and collected blood result data from the preceding 2 years. Normal ranges were determined by electronic health record ranges. In total, 102 patients were included (male : female ratio 47 : 55, median age 48.5 years). Adalimumab (n = 39), ustekinumab (n = 36) and risankizumab (n = 13) were the most prescribed biologics. Ten patients were prescribed oral systemic therapy (six methotrexate and four acitretin). The median blood monitoring interval was 5 months. Overall, blood abnormalities were present in 38 of 102 patients (37.2%). Transaminitis was most common (n = 23, all ≤ 80 U L−1): ten had documented liver disease and two were coprescribed methotrexate. Two patients had abnormalities requiring immediate retesting (acute kidney injury and new anaemia) and 36 had mild abnormalities. Fourteen patients had developed abnormalities since commencing biologic therapy [neutrophilia, n = 2; neutropenia, n = 1 (adalimumab); lymphopenia, n = 1 (ustekinumab); transaminitis, n = 8; thrombocytosis, n = 2; thrombocytopenia, n = 1; anaemia n = 1; low urea, n = 1; raised creatinine, n = 1]. Despite abnormalities present in 37% of patients, the majority were mildly deranged and only 14 patients developed the abnormality after commencing biologic therapy. Many of these patients have multiple long-term conditions, monitored in other clinics. None of the blood abnormalities detected was directly attributed to commencing the biologic or prompted stopping biologic therapy. Our data support that a more targeted and coordinated approach to blood monitoring could be adopted and should be formally assessed. Applying sustainable healthcare coalition and government vehicle emission figures to findings from a survey of patients with psoriasis prescribed a biologic in our department, we estimate an annual carbon saving of &gt; 850 kg CO2 equivalents (CO2e) for patient travel alone if monitoring for patients with no specific risk factors became annual. When considering addition factors, such as building energy and consumables disposal, this saving could rise to &gt; 6400 kg CO2e. Up to 60% of patients miss work to attend appointments and, for a minority, earnings are consequently lost (outpatient survey data). Evidently, more targeted monitoring could substantially reduce carbon emissions, disruption to employment and associated healthcare costs. Further evaluation through larger studies is required to ensure ongoing safe prescribing with personalized blood monitoring.