I Rodríguez-Lago, C Herrera-deGuise, M Boscá-Watts, C Rodríguez, E Leo, M Calvo, F Cañete, S Chacón, C Cuarán, A Elorza, E Guerra, E Iglesias, D Sánchez, M Barreiro-de Acosta, D Ginard, J L Cabriada Journal of Crohn’s and Colitis, Volume 18, Issue Supplement_1, January 2024, Page i1135, doi.org=10.1093/ecco-jcc/jjad212.0712

Background
Granulocyte–monocyte apheresis (GMA) selectively removes activated leukocytes and immune mediators, and it has shown to be safe and effective in treating ulcerative colitis (UC). Previous reports have also described its combination with biologics, mainly with anti-TNF.

Methods
The aim of our study was to evaluate the clinical efficacy and safety of combining GMA after primary non-response (PNR) or loss of response (LOR) to ustekinumab (UST) in patients with UC. A retrospective, multicentric study was performed in 12 IBD Units, including all patients with refractory UC who received combined GMA plus UST. The number of GMA sessions, its frequency, filtered blood volume and time of each session were compiled, along with the clinical data. Efficacy was assessed 1 and 6 months after finishing the GMA by partial Mayo score, CRP and faecal calprotectin. Data regarding UST intensification, need for new immunomodulators/biologics and surgery were also compiled. Descriptive statistics and non-parametric tests were used in the statistical analysis.

Results
Nineteen patients were included (15 UC, 2 Crohn’s disease, 2 unclassified IBD; median age 48 years (IQR, 36-63); 68% male). At baseline, 78% were receiving steroids and 23% immunomodulators. Most patients (89%) had prior exposure to anti-TNF agents and 53% to vedolizumab. Baseline Mayo score was 6.5 (IQR, 5-7), with a median CRP of 9 mg/L (IQR, 4.8-20.8) and faecal calprotectin 1,612 mg/kg (IQR, 873-4,152). GMA was started mostly after PNR in 83%, the median number of GMA sessions was 16 (IQR, 11-27) and 50% of patients started maintenance GMA. Partial Mayo score significantly decreased 6 months after the last GMA session (p=0.019). During follow-up, 27% started a new biologic therapy and 13% required surgery. 64% of patients under steroids at baseline were able to stop them. Adverse events were reported in 5% of patients.

Conclusion
GMA can safely recapture the response to UST in refractory patients after PNR or LOR to this drug.