Assessment of immunodeficiency scoring index performance in enterovirus/rhinovirus respiratory infection after allogeneic hematopoietic stem cell transplantation

Background Enterovirus/rhinoviruses (EvRh) are the most common cause of respiratory virus infections in recipients of allogeneic stem cell transplantation (allo-HSCT). Objective We sought to analyze the value of the immunodeficiency scoring index (ISI) in predicting lower respiratory tract disease (LRTD) progression and mortality in a prospective cohort of consecutive adult (>16 years) allo-HSCT recipients with EvRh infection from December 1 2013 to December 1 2019 at two Spanish transplant centers. Results We included 234 allo-HSCT recipients with 383 EvRh episodes. Out of 383 EvRh episodes, 98 (25%) had LRTD. Multivariate logistic regression analysis identified three independent factors associated with LRTD progression: Ig G < 400 mg/dL, community-acquired respiratory virus (CARV) co-infection and high-risk ISI. Inclusion of Ig G levels and CARV co-infection in the ISI improved its performance by significantly increasing the area under the receiver operator characteristic curve (AUROC) from 0.643 to 0.734 (P = .03). Likewise, the two conditions identified by multivariate analyses as associated with higher probability of mortality were high-risk ISI and EvRh infection within 6 months after transplant. Conclusions Our findings confirm the value of high-risk ISI in predicting both probability of EvRh LRTD and 3-month overall mortality. We also demonstrate that the original ISI could be adapted to other CARV types by including additional variables to improve its performance.