Mismatched donor cell infusion-related syndrome following microtransplant in patients with acute myeloid leukemia.

Background: Immunotherapies such as adoptive immune cell infusion and immune-modulating agents are widely used for cancer treatment, and the concomitant symptoms, including cytokine release syndrome (CRS) or immune-related adverse events (irAEs), are frequently reported. However, clinical manifestations induced by mismatched donor granulocyte colony-stimulating factor mobilized peripheral blood mononuclear cell (GPBMC) infusion in patients receiving microtransplant (MST) have not yet been well depicted.

Methods: We analyzed 88 cycles of mismatched GPBMC infusion in patients with acute myeloid leukemia receiving MST and 54 cycles of chemotherapy without GPBMC infusion as a comparison. Clinical symptoms and their correlation with clinical features, laboratory findings, and clinical response were explored.

Results: Fever (58.0% [51/88]) and chills (43.2% [38/88]) were the significant early-onset symptoms after GPBMC infusion. Patients possessing less human leukocyte antigen-matching loci with the donor or those with unrelated donors experienced more chills (3 [2-5] loci vs. 5 [3-5] loci, P  = 0.043 and 66.7% [12/18] vs. 37.1% [26/70], P  = 0.024). On the other hand, those with decreased CD4 + /CD8 + T-cell ratio developed more fever (0.8 [0.7-1.2] vs. 1.4 [1.1-2.2], P  = 0.007). Multivariable analysis demonstrated that younger patients experienced more fever (odds ratio [OR] = 0.963, 95% confidence interval [CI]: 0.932-0.995, P  = 0.022), while patients with younger donors experienced more chills (OR = 0.915, 95% CI: 0.859-0.975, P  = 0.006). Elevated ultra-sensitive C-reactive protein levels in the absence of cytokine storm were observed following GPBMC infusion, which indicated mild and transient inflammatory response. Although no predictive value of infusion-related syndrome to leukemia burden change was found, the proportion of host pre-treatment activated T cells was positively correlated with leukemia control.

Conclusions: Mismatched GPBMC infusion in MST induced unique infusion-related symptoms and laboratory changes, which were associated with donor- or recipient-derived risk factors, with less safety and tolerance concerns than reported CRS or irAEs.