Backgrounds:

Human adenovirus (hAdV) infection constitutes an important cause of morbidity and mortality in immunocompromised patients as solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients.

Cidofovir is the most prescribed treatment even though its use is controversial specially in asymptomatic patients. Strategies like reducing immunosuppression, or lymphocyte infusions have not yet been well described.

This study aims to describe the impact and therapeutic management of hAdV infection in immunocompromised patients

Methods

Retrospective study examining episodes of positive hAdV viremia (>1.000 copies/mL) in immunocompromised hosts during a four-year follow-up (2017-2021) at a reference centre. Demographic, clinical, epidemiological, and microbiological data, lymphocyte count, therapeutic management, and outcome were collected and analysed.

Results:

49 immunosuppressed patients (median age 9 years; interquartile range IQR 1.0-16.0) were included. Main causes of immunosuppression were HSCT (38/49: 77.6%), hematologic malignancies (30/49; 61.2%), and SOT (11/49: 22.4%).

25 patients (51%) were symptomatic (mainly febrile syndrome and diarrhoea). Thirteen patients (26.5%) presented a viral coinfection with CMV or BK virus. Cidofovir was prescribed in 24 patients (49%). Other therapeutic measures included administration of intravenous immunoglobulins (18.4%), reducing immunosuppression (14.3%) and memory T-cell infusion (12.2%).

Cidofovir use was significantly (p<0.05) associated with presence of hAdv symptoms, lower lymphocyte count, ICU admission and high viral load (Table 1).

Despite treatment, 11 patients (45.8%) presented persistent positive viremias (associated with lower lymphocyte count p<0.05) and three patients died because hAdV infection (acute liver failure, septic shock).

Conclusions/Learning Points:

hAdV infections had high morbidity and mortality in our series. Patients with low lymphocyte count are at higher risk of persistent positive viremias and short-term survival. We did not observe a clear association between resolution of infection and Cidofovir use.