Title: Risk factors for non-infectious diarrhea of patients with multiple myeloma after chimeric antigen receptor T-cell immunotherapy: A retrospective observational study

Abstract Purpose To ascertain the risk factors and prevalence of non-infectious diarrhea among participants with multiple myeloma who treated with chimeric antigen receptor T-cell immunotherapy. Methods This study enrolled 88 patients with multiple myeloma who received chimeric antigen receptor T-cell immunotherapy at one tertiary general hospital in China. Participants were categorized into diarrhea subgroup and non-diarrhea subgroup according to the occurrence of diarrhea. Demographic data and self-reported measurements and planning were obtained from questionnaires and clinical data from hospital databases. Results In total, 50 patients suffered from non-infectious diarrhea, with the prevalence of 56.8%. Multiple logistic regression analysis showed that severe cytokine release syndrome (OR = 5.980), underlying diseases (OR = 4.184), previous treatment lines ≥ 6 (OR = 6.292) were prominent hazardous factors for non-infectious diarrhea ( p < 0.05). Conclusion The incidence rate of non-infectious diarrhea in patients with multiple myeloma after CAR-T therapy was at a high level. Severe cytokine release syndrome, previous treatment lines ≥ 6 and the underlying diseases were important predictors for non-infectious diarrhea. Medical staff should early evaluate these major factors to reduce the risk of diarrhea (184 words).