METHODS: Autologous HSCT patients aged 18 years old and above were recruited from Hospital Ampang, Malaysia, between April 2019 to December 2020. Mucositis assessments were conducted daily, whilst blood and saliva were collected prior to conditioning regimen, on Day 0, Day+7 and 6-month. Baseline and inflammatory predictors in a repeated time measurement of moderate-severe mucositis were assessed by multiple logistic regression and generalized estimating equations, respectively.

RESULTS: Of the 142 patients analyzed, oral mucositis and diarrhea (representing GI mucositis) were reported as 68.3% and 95.8%, respectively. Predictive factors for moderate-severe oral mucositis were BEAM or busulphan-based regimens (odds ratio (OR)=9.2, 95% confidence interval (CI)=1.16-72.9, p-value (p) = 0.005) and vomiting (OR=4.6, 95% CI 1.68-12.3, p = 0.004). Predictive factors for moderate-severe GI mucositis were BEAM or busulphan-based regimens (OR=3.9, 95% CI 1.05-14.5, p = 0.023), female sex (OR = 3.3, 95% CI 1.43-7.44, p = 0.004) and body mass index (OR=1.08, 95% CI 1.02-1.15, p = 0.010). Cytokines analyses were performed in 96 patients. Saliva and plasma interleukin-6 (OR=1.003, 95% CI 1.001-1.004, p < 0.001 and OR=1.01, 95% CI 1.001-1.015, p = 0.029), and plasma tumor necrosis factor-alpha (OR=0.91, 95% CI 0.85-0.99, p = 0.019) were predictive of moderate-severe oral mucositis in a time-dependent model.

AREAS COVERED: This review covers issues pertinent to infection in the HSCT patient, including bacterial and viral infection; strategies to reduce GVHD; infection patterns; resistance and treatment options; adverse drug reactions to antimicrobials, problems of antimicrobial resistance; perturbation of the microbiome; the role of prebiotics, probiotics, and antimicrobial peptides. We highlight potential strategies to minimize the use of antimicrobials.