Trends in Clinical Indications for Plasma Exchange in Adult Patients Between 2008 and 2024 in Bogotá, Colombia

This multicenter retrospective study aimed to describe temporal trends in clinical indications for plasma exchange (PE) in adult patients at four quaternary-care hospitals in Bogotá (2008-2024) and to examine their distribution across successive ASFA guideline editions. Adults ≥ 18 years who received ≥ 1 PE session were included; indications were coded using ICD-10, and outcomes were classified as complete improvement, partial improvement, no change, or death. Descriptive statistics were performed using RStudio. Of 970 patients screened, 758 met eligibility criteria. Median age was 47 years (IQR 33-60); 62.4% were women. Neurological and rheumatological indications predominated (n = 634, 83.6%), particularly neuromyelitis optica spectrum disorders and ANCA-associated vasculitis. A total of 3954 sessions were performed (median: 5 per patient; IQR: 5-6). Hypocalcemia was the most frequent complication. Overall, 74.0% achieved complete or partial improvement, with higher rates in neurological conditions. Sixty-nine deaths occurred (9.1%), mostly attributed to systemic autoimmune diseases. Over the study period, neuroimmunological indications increased markedly, while use of PE for ANCA-associated vasculitis declined following its reclassification to ASFA category III in 2023. ASFA categories I and II accounted for 92.7% of indications; Category I representation declined from 66.7% (2008-2010) to 40.6% (2023-2024), while case volume grew from 21 to 266 patients per triennium. Over 16 years, PE indications shifted substantially toward immune-mediated neurological disorders, driven by expanded diagnostic availability for AQP4-IgG and MOG-IgG and evolving ASFA recommendations. These findings underscore the need for prospective studies and a national PE registry in Colombia.