Depuis la disponibilité des combinaisons antirétrovirales (cART) en 1996, l’incidence des infections opportunistes classantes SIDA (IO), dont la pneumocystose (PCP) a très fortement diminué. Malgré tout, chez les patients infectés par le VIH, la PCP était la 2ème IO la + fréquente en France en 2001-2003 et les infections fongiques, avec 1 million de nouveaux cas/an de cryptococcose, restent un problème de santé publique majeur au niveau mondial. Cependant, depuis l’ère des cART, très peu de recherches épidémiologiques sur les infections fongiques dans les pays industrialisés ont été entreprises. C’est dans ce contexte que nous avons mené une étude épidémiologique de 2 infections fongiques chez les patients infectés par le VIH en France sur la French Hospital Database on HIV ANRS CO4 (FHDH) : la pneumocystose et l’aspergillose invasive. Concernant la pneumocystose, sur la période 2004-2011, dans la base FHDH, la moitié des 1259 cas de PCP étaient survenus chez des patients qui avaient interrompus leur suivi, et, pour ceux qui avaient déjà eu une IO avant la PCP, leur mortalité était de 25% à 3 ans. Pour l’aspergillose invasive (AI), après un retour national aux dossiers des cas déclarés sur 20 ans sur la base FHDH, un comité d’experts a validé 242 cas d’AI. Les données montrent que, chez les patients infectés par le VIH, seulement la moitié des AI validées répondaient aux critères EORTC. La mortalité à 3 mois après une AI s’est améliorée après l’ère des cART et un rôle protecteur du voriconazole sur la survie à 3 mois a également été démontré pour la 1ère fois chez les patients infectés par le VIH. / The advent of combined antiretroviral therapy (cART) in 1996 resulted in a dramatic fall in the incidence of AIDS-defining illness (ADI), including Pneumocystis jirovecii pneumonia (PCP). Nevertheless, PCP was the second most frequent ADI in France in 2001-2003 and fungal infections remain a major threat for HIV-infected individuals worldwide. Epidemiological data on fungal infections in the late cART period in resource-rich settings are scarce. The purpose of our work was to study changes in the epidemiology of fungal infections among HIV-infected individuals in France in the late cART period, focusing on PCP and invasive aspergillosis (IA) in the French Hospital Database on HIV ANRS CO4 (FHDH). In the FHDH, during the 2004-2011 period, half of the 1259 PCP cases occurred among HIV-infected individuals who had waning adherence to care, and for those who had a prior ADI before PCP the 3-year mortality rate was 25%. For the second study on IA, a review committee validated IA cases among all the cases that included a diagnostic code for aspergillosis (ICD-9 or ICD-10) in the FHDH over a 20-year period. Our study demonstrated that only half of validated IA cases among HIV-infected individuals met EORTC criteria. The 3-months survival rate after IA diagnosis improved after the advent of cART and a protective role of voriconazole was observed in the period after 2001.

The overall aim of this thesis is to improve knowledge about the prevention of infectious and bleeding complications in patients with hematological malignancies, primarily in those with chronic lymphocytic leukemia (CLL) and myelodysplatic syndrome (MDS). Hypogammaglobulinemia, impaired production of immunoglobulins (Ig), is an established risk factor for infection, but the impact of IgG pure subclass deficiency (IgG subclass deficiency with adequate production of IgG, IgA, and IgM) has been debated. In a retrospective single institution study, we concluded that pure IgG subclass deficiency in CLL patients is rare and is not associated with an increased risk of infection. Hence, routine analysis of IgG subclasses in patients with CLL is not warranted. There is no consensus on recommending vaccination against Streptococcus pneumoniae to CLL patients mainly because comparative studies are lacking. In our randomized trial, the efficacy of a conjugated pneumococcal vaccine on immune response was superior or equal to a polysaccharide vaccine for all pneumococcal serotypes common for the two vaccines. A conjugate pneumococcal vaccine should therefore be included in vaccination programs for patients with CLL. Bronchoalveolar lavage (BAL) is a well-established invasive method to identify the cause of pulmonary infiltrates in immunocompromised patients. In a retrospective trial, we have studied the diagnostic yield of BAL in patients with hematological malignancies. We concluded that BAL is highly useful in either verifying or excluding some of the important respiratory tract infections affecting these patients, particularly invasive pulmonary aspergillosis (IPA) and Pneumocystis jirovecii pneumonia (PJP). However, standardized procedures for BAL sampling should be continually revised to avoid unnecessary microbiological tests. Thrombocytopenia, an adverse prognostic factor in patients with MDS, can be aggravated by azacitidine, first-line treatment for high-risk MDS. Eltrombopag, a thrombopoietin-receptor agonist (TPO-R), alleviates thrombocytopenia in patients with immune thrombocytopenic purpura (ITP). In a phase I clinical trial, we concluded that the combination of eltrombopag and azacitidine in high-risk MDS patients with thrombocytopenia is feasible and well tolerated in doses up to 200 mg eltrombopag daily.