Fondazione IRCCS Ca' Granda

The aim of this observational study is to determine if and how kidney failure affects the development of protective immune responses following vaccination in patients on chronic dialysis.
Researchers will compare the effectiveness of the influenza vaccine in inducing protective antibodies between hemodialysis patients and subjects without chronic kidney disease.
Participants will:
* Be enrolled at the time of influenza vaccination
* Visit the clinic at 7, 14, 30, 60, and 120 days after vaccination
* Be asked to provide relevant clinical information and a blood sample at each visit

Pharmacological, single-center, non-profit observational study.
The present study is part of a cooperation project between the SC Gastroenterology and Hepatology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico (Milan, Italy), the University of Milan, the University of Parma and Rome Tor Vergata, funded under the call for Research Projects of Significant National Interest - 2022 PNRR Call (Prot. P2022WEXP2).
Hepatitis D virus (HDV) is a defective RNA virus, which requires the presence of hepatitis B virus (HBV) to infect liver cells and propagate. To date, the mechanisms underlying the accelerated disease progression in the natural history of Delta hepatitis are poorly understood, as is the course of the HDV-specific immune response (CD4 and CD8 T cells). As in chronic HBV and HCV infections, the outcome of chronic HDV infection appears to be dictated primarily by the host immune response, which represents a key determinant for virus control or persistence. For HBV/HDV coinfection, the role of T cells has not been well defined, as suitable animal models are lacking and so far few HDV-specific T cell epitopes have been precisely mapped, mainly limited to HLA-B alleles.
The study is divided into two substudies (cross-sectional and longitudinal). The primary objective of the cross-sectional study is to calculate the prevalence of HDV-specific T responses in patients with chronic HBV-HDV infection naïve to treatment with Bulevirtide. The primary objective of the longitudinal study is the change in the prevalence of HDV-specific T responses in patients with chronic HBV-HDV infection during treatment with Bulevirtide compared to baseline (pre-treatment).

There are currently no clinical and laboratory data that well characterize this neutropenia associated with the Duffy-null phenotype, particularly for pediatric subjects. In particular there are no data on the frequency of immune neutropenia in DANC neutropenic pediatric subjects.
The goal of this study is to :
* define the frequency of immune neutropenia within the cohort of DANC subjects under study
* evaluate the frequency of different degrees of neutropenia (mild-moderate-severe);
* evaluate the possible association between different degrees of neutropenia and the presence of infections.