[Infectious and neoplasic complications after kidney transplantation]. / Complications infectieuses et néoplasiques après transplantation rénale.

Infections and malignancies are the expected complications of immunosuppressive therapy, which non-specifically impairs cellular and humoral immune responses in renal transplant recipients. Infections were usually frequent and severe during the early post-transplant period (first year). Recent diagnostic methods (molecular biology) and availability of new antivirals, antifungal and antibiotic drugs made rapid diagnosis and systematic preventive strategies much easier and this resulted in a significant reduction of infections and infectious death in this population. However, new infectious agents like BK polyomavirus, hepatitis E virus, parvovirus (as well as Chigunkunya, West Nile and others in particular areas) were recently recognized as responsible of aggressive infections in the immunocompromised host. Malignancies are also common after transplantation, due to the intensity and duration of immunosuppression. Skin cancers and lymphoproliferative disorders are the most common and are undoubtedly caused by viral infections, but incidence of non-skin cancers is also increased. After reduction of immunosuppression, treatment is similar to non-transplant patients: Results are usually poor and cancer is now the third cause of death in transplant recipients. Due to their anti-proliferative and anti-tumoral properties, incidence of de novo cancer significantly decreased in patients receiving mTor inhibitors as maintenance immunosuppression; furthermore, in patients already diagnosed with Kaposi sarcoma or recurrent skin cancers, introduction of mTor was associated with stabilisation and/or regression of malignant lesions.

The general picture of uremia.

The clinical presentation and manifestations of uremia that constitute the uremic syndrome are presented. The first descriptions of patients with advanced or "terminal" renal failure who were treated with hemodialysis are evoked to illustrate the wide range of signs and symptoms that are associated even to a moderate decrease in renal function, presently referred to as chronic kidney disease (CKD) stages 3-4. The kidney is a central organ guaranteeing the maintenance of the "milieu intérieur," where all the cells of the body are generated, develop, proliferate, and die. Chronic kidney disease, by altering the "milieu intérieur," may alter the metabolism of every type of cell or organ, leading to a wide scope of symptoms. The most frequently observed signs in daily clinical practice are summarized and put into the perspective of the renal physician. Disturbances of ion and water metabolism, hypertension, cardiovascular disease, anemia, mineral and bone disorders, endocrine, inmmunologic and neurologic syndromes are described. The addition of these clinical manifestations defines and describes each uremic patient as a specific individual. The pathophysiologic mechanisms by which each of these signs and symptoms appears and the particular compounds responsible for their occurrence, are described in depth in subsequent chapters of this issue.

Does reduction in immunosuppression in viremic patients prevent BK virus nephropathy in de novo renal transplant recipients? A prospective study.

BACKGROUND: BK virus nephropathy (BKVN) is a severe complication of renal transplantation, resulting in graft loss in >50% of cases. Because patients with BKV viremia are at high risk for developing BKVN, the aim of our study was to analyze whether early reduction of immunosuppression (IS) could prevent BKVN in viremic patients. METHODS: BKV viruria was prospectively screened every 3 months by real-time polymerase chain reaction during the first year after transplantation in 123 consecutive renal transplant recipients. Plasma viral load was measured by polymerase chain reaction whenever viruria was positive; in viremic patients a graft biopsy was systematically performed and IS was reduced. RESULTS: Viruria, viremia, and BKVN occurred in 48.8%, 10.5%, and 2.4% of patients, respectively. In the 13 patients with positive viremia, initial graft biopsy showed BKVN in two. After reduction of IS in patients without BKVN, viremia disappeared in 8 of 11, decreased in 2 of 11, and increased in one patient who eventually developed BKVN. In contrast, viremia remained positive in one patient with BKVN and disappeared in the second but renal function deteriorated in both of them. Initial viral load was higher in patients who developed BKVN. CONCLUSION: Reduction of IS is probably an effective therapeutic option to clear viremia and prevent BKVN in viremic renal transplant patients.