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Background. Caspofungin (CAS) has recently been approved for treatment of invasive aspergillosis. In clinical trials, CAS-induced nephrotoxicity was markedly less pronounced compared to amphotericin B (AmB). Nevertheless, in a recent trial, nephrotoxicity in CAS-treated patients was considerably more pronounced than in preceding studies. Therefore, the aim of this study was to assess toxic effects of CAS on human renal proximal and distal tubular epithelial cells (PTC and DTC) in vitro, and to compare them to those of AmB.Methods. Cells were isolated from human kidney tissue, and exposed to clinically relevant concentrations of CAS and AmB for 24 h. Total DNA content and cell viability were determined by DAPI staining and a modified MTT assay. For testing of cytotoxicity, LDH activity was measured in cell culture supernatants. To assess apoptotic effects, AnnexinV-binding assay and DAPI staining for detection of fragmented DNA were performed.Results. DTC were more vulnerable towards the antifungal agents than PTC. In contrast to AmB, cell-damaging effects of CAS were less severe. DAPI staining revealed slight and dose-dependent antiproliferative effects of CAS at concentrations reflecting relevant plasma levels. At these concentrations, cell viability, determined by MTT assay, was not decreased in PTC and DTC. LDH release was marginally increased in a dose-dependent manner; apoptosis was not detected. Nevertheless, at CAS concentrations reflecting potential tissue concentrations, cell damaging effects were considerably more pronounced.Conclusion. Our results suggest that CAS is less nephrotoxic than AmB in vitro. The antiproliferative and cytotoxic effects of CAS predominantly affect DTC, which seem to be more susceptible to CAS-induced damage. [ABSTRACT FROM AUTHOR]

Background. With increasing life spans of HIV-infected individuals under highly active antiretroviral therapy, long-term consequences of the chronic infection and antiretroviral treatment are becoming more prevalent. Data on prevalence and consequences of hypertension are limited, but recent studies suggest that HIV-infected individuals are at a higher risk of developing hypertension.Methods. In this prospective study, HIV-1-infected patients from the Frankfurt AIDS Cohort Study (FACS) were followed for 1 year to determine the frequency of systemic hypertension and to assess the associated clinical and demographic factors.Results. A total 214 HIV-1-infected patients, predominantly Caucasian males, participated in the study. Prevalence of systemic hypertension was 29%. The groups of hypertensive and normotensive individuals were comparable in terms of ethnic background and duration of infection. As in the general population, hypertensive subjects were older (49.1±11.1 vs 39.0±8.1 years; P<0.0001) and waist-to-hip ratio was higher than in normotensive individuals (0.99±0.07 vs 0.93±0.08; P<0.0001). Hypertension was associated with a much higher frequency of persistent proteinuria (41.1% vs 2.8%; P<0.001), coronary heart disease (16.1% vs 1.3%; P<0.0001) and myocardial infarction (8.1% vs 0.7%; P<0.005), whereas most cardiovascular risk factors were similar in both groups.Conclusions. Our data do not demonstrate any association between the presence of hypertension and antiretroviral therapy or immune status. However, hypertension seems to have a high impact on the existing risk for premature cardiovascular disease. Furthermore, overt proteinuria is frequent in HIV-1 infection with hypertension and might be due to hypertensive nephrosclerosis as well as yet undefined renal disease in these patients. [ABSTRACT FROM AUTHOR]

Background. Interleukin-6 (IL-6) is a multifunctional cytokine which regulates immune responses and host defence mechanisms. IL-6 has been found to be increased in certain inflammatory conditions of the kidney, in which tubular epithelial cells play a pivotal role. Human renal tubular cells express IL-6. Until now no data about the effect of the immunosuppressant drug mycophenolic acid (MPA) on IL-6 expression were available. Methods. Proximal and distal tubular epithelial cells (PTC/DTC) have been isolated immunomagnetically. Confluent monolayers were stimulated with interleukin-1β (IL-1β; 25 U/ml), IL-1β+ MPA (0.25-50 μM) or MPA alone for 48 h. Release of IL-6 protein into the supernatant was evaluated with an enzyme immunoassay, IL-6 mRNA expression was evaluated using the Quantikine mRNA kit. Results. After IL-1β stimulation, a highly significant 2.6- (PTC) and 3.8-fold (DTC) upregulation of IL-6 expression was detectable. IL-6 mRNA was upregulated by IL-1β [1.57- (PTC) and 2.03-fold (DTC)]. MPA inhibited this cytokine-induced IL-6 expression in a dose-dependent manner. Incubation with the lowest MPA concentration had no effect on the stimulated upregulation, whereas all higher doses significantly decreased IL-6 expression. Dexamethasone significantly inhibited the cytokine-induced IL-6 protein release in PTC, but not in DTC. Conclusions. In this study we demonstrated for the first time an inhibitory effect of MPA on the stimulated IL-6 expression of renal tubular epithelial cells. In contrast to older data, which showed a synergistic upregulation of the expression of a CC-chemokine by a combination of cytokines and MPA, in the present study we could demonstrate an immunosuppressive effect of MPA on the expression of an important cytokine. [ABSTRACT FROM AUTHOR]