High Serum miR-361-3p Predicts Early Postdischarge Infections after Autologous Stem Cell Transplantation

Autologous hematopoietic stem cell transplantation (AHSCT) is currently the backbone of the treatment of multiple myeloma (MM) and relapsed and refractory lymphomas. Notably, infections contribute to over 25% of fatalities among AHSCT recipients within the initial 100 days following the procedure. In this study, we aimed to evaluate three selected miRNAs: hsa-miR-155-5p, hsa-miR-320c, and hsa-miR-361-3p, in identifying AHSCT recipients at high risk of infectious events up to 100 days post-transplantation after discharge.

The study group consisted of 58 patients (43 with MM, 15 with lymphoma) treated with AHSCT. Blood samples were collected from all patients at the same time point: on day +14 after transplantation.

Fifteen patients (25.9%) experienced infectious complications after post-transplant discharge within the initial +100 days post-transplantation. The median time to infection onset was 44 days (interquartile range, 25-78). Four patients required hospitalization due to severe infection. High expression of hsa-miR-361-3p (fold change [FC], 1.79; P=0.0139) in the patients experiencing infectious complications and overexpression of hsa-miR-320c (FC, 2.14; P<0.0001) in patients requiring hospitalization were observed. In the multivariate model, both lymphoma diagnosis (odds ratio [OR], 6.88; 95% confidence interval [CI], 1.55-30.56; P=0.0112) and high expression of hsa-miR-361-3p (OR, 3.00; 95% CI, 1.40-6.41; P=0.0047) were independent factors associated with post-discharge infectious complications occurrence. Our model in 10-fold cross-validation preserved its diagnostic potential with an area under the receiver operating characteristic curve of 0.78 (95% CI, 0.64-0.92).

Elevated serum hsa-miR-361-3p emerges as a promising biomarker for identifying patients at risk of infection during the early post-discharge period, potentially offering optimization of the prophylactic use of antimicrobial agents tailored to the specific risk profile of each AHSCT recipient.