Mitochondrial changes during D-drug-containing once-daily therapy in HIV-positive treatment-naive patients.

BACKGROUND: Antiviral drugs of the category of nucleoside reverse transcriptase inhibitors (NRTIs), largely used for the treatment of HIV infection, can have toxic effects on mitochondria. We performed a cross-sectional study on mitochondrial toxicity in a randomized group of patients belonging to a larger randomized study on different NRTI-based once-daily regimens by quantifying mitochondrial DNA (mtDNA), three different mitochondrial RNAs (mtRNAs) and functional parameters in highly purified peripheral CD4+ and CD8+ T-cells. METHODS: A total of 49 previously treatment-naive patients treated for a mean of 15 months with efavirenz plus didanosine plus lamivudine (group 1), or tenofovir disoproxil fumarate plus lamivudine (group 2), or didanosine plus abacavir (group 3) were considered. The groups were matched for sex, age, CDC classification, risk factor for HIV, nadir CD4+ T-cell count and baseline viral load. mtDNA and mtRNA were quantified by using real-time PCR assays. RESULTS: No patient showed any clinical symptom; however, the amount of mtDNA in CD4+ and CD8+ T-cells was significantly lower in groups 1 and 3; similarly, the expression of different mtRNAs in both CD4+ and CD8+ T-cells showed significant differences that were dependent upon the drug used. No differences were found in mitochondrial membrane potential and mitochondrial mass in peripheral lymphocytes. The amount of total HIV DNA in CD4+ T-cells did not differ among the groups, who displayed a similar immune reconstitution and control of the virus. CONCLUSIONS: An efficient didanosine-containing once-daily therapy can have more mitochondrial toxicity than regimens devoid of this drug.

Health care-associated native valve endocarditis: importance of non-nosocomial acquisition.

BACKGROUND: The clinical profile and outcome of nosocomial and non-nosocomial health care-associated native valve endocarditis are not well defined. OBJECTIVE: To compare the characteristics and outcomes of community-associated and nosocomial and non-nosocomial health care-associated native valve endocarditis. DESIGN: Prospective cohort study. SETTING: 61 hospitals in 28 countries. PATIENTS: Patients with definite native valve endocarditis and no history of injection drug use who were enrolled in the ICE-PCS (International Collaboration on Endocarditis Prospective Cohort Study) from June 2000 to August 2005. MEASUREMENTS: Clinical and echocardiographic findings, microbiology, complications, and mortality. RESULTS: Health care-associated native valve endocarditis was present in 557 (34%) of 1622 patients (303 with nosocomial infection [54%] and 254 with non-nosocomial infection [46%]). Staphylococcus aureus was the most common cause of health care-associated infection (nosocomial, 47%; non-nosocomial, 42%; P = 0.30); a high proportion of patients had methicillin-resistant S. aureus (nosocomial, 57%; non-nosocomial, 41%; P = 0.014). Fewer patients with health care-associated native valve endocarditis had cardiac surgery (41% vs. 51% of community-associated cases; P < 0.001), but more of the former patients died (25% vs. 13%; P < 0.001). Multivariable analysis confirmed greater mortality associated with health care-associated native valve endocarditis (incidence risk ratio, 1.28 [95% CI, 1.02 to 1.59]). LIMITATIONS: Patients were treated at hospitals with cardiac surgery programs. The results may not be generalizable to patients receiving care in other types of facilities or to those with prosthetic valves or past injection drug use. CONCLUSION: More than one third of cases of native valve endocarditis in non-injection drug users involve contact with health care, and non-nosocomial infection is common, especially in the United States. Clinicians should recognize that outpatients with extensive out-of-hospital health care contacts who develop endocarditis have clinical characteristics and outcomes similar to those of patients with nosocomial infection. PRIMARY FUNDING SOURCE: None.

Increasing clinical virulence in two decades of the Italian HIV epidemic.

The recent origin and great evolutionary potential of HIV imply that the virulence of the virus might still be changing, which could greatly affect the future of the pandemic. However, previous studies of time trends of HIV virulence have yielded conflicting results. Here we used an established methodology to assess time trends in the severity (virulence) of untreated HIV infections in a large Italian cohort. We characterized clinical virulence by the decline slope of the CD4 count (n = 1423 patients) and the viral setpoint (n = 785 patients) in untreated patients with sufficient data points. We used linear regression models to detect correlations between the date of diagnosis (ranging 1984-2006) and the virulence markers, controlling for gender, exposure category, age, and CD4 count at entry. The decline slope of the CD4 count and the viral setpoint displayed highly significant correlation with the date of diagnosis pointing in the direction of increasing virulence. A detailed analysis of riskgroups revealed that the epidemics of intravenous drug users started with an apparently less virulent virus, but experienced the strongest trend towards steeper CD4 decline among the major exposure categories. While our study did not allow us to exclude the effect of potential time trends in host factors, our findings are consistent with the hypothesis of increasing HIV virulence. Importantly, the use of an established methodology allowed for a comparison with earlier results, which confirmed that genuine differences exist in the time trends of HIV virulence between different epidemics. We thus conclude that there is not a single global trend of HIV virulence, and results obtained in one epidemic cannot be extrapolated to others. Comparison of discordant patterns between riskgroups and epidemics hints at a converging trend, which might indicate that an optimal level of virulence might exist for the virus.

The relationship between the initiation of antimicrobial therapy and the incidence of stroke in infective endocarditis: an analysis from the ICE Prospective Cohort Study (ICE-PCS).

BACKGROUND: Embolic events to the central nervous system are a major cause of morbidity and mortality in patients with infective endocarditis (IE). The appropriate role of valvular surgery in reducing such embolic events is unclear. The purpose of this study was to determine the relationship between the initiation of antimicrobial therapy and the temporal incidence of stroke in patients with IE and to determine if this time course differs from that shown for embolic events in previous studies. METHODS: Prospective incidence cohort study involving 61 tertiary referral centers in 28 countries. Case report forms were analyzed from 1437 consecutive patients with left-sided endocarditis admitted directly to participating centers. RESULTS: The crude incidence of stroke in patients receiving appropriate antimicrobial therapy was 4.82/1000 patient days in the first week of therapy and fell to 1.71/1000 patient days in the second week. This rate continued to decline with further therapy. Stroke rates fell similarly regardless of the valve or organism involved. After 1 week of antimicrobial therapy, only 3.1% of the cohort experienced a stroke. CONCLUSIONS: The risk of stroke in IE falls dramatically after the initiation of effective antimicrobial therapy. The falling risk of stroke in patients with IE as a whole precludes stroke prevention as the sole indication for valvular surgery after 1 week of therapy.

Effect of adherence to HAART on virologic outcome and on the selection of resistance-conferring mutations in NNRTI- or PI-treated patients.

BACKGROUND: The effect of adherence on the risk of virologic failure and mutations selection was verified in a prospective study. METHOD: At baseline, all patients had a viral load (VL) <50 copies/mL and completed a self-reported questionnaire. Patients were followed for the subsequent 4 months to document virologic rebound (VL > 50 copies/mL). RESULTS: 1,133 patients completed 2,240 questionnaires/follow-up (non-nucleoside reverse transcriptase inhibitor [NNRTI] = 1,479; single protease inhibitor [PI] = 200; boosted PI = 561). Only the type of treatment and the baseline adherence rate were significantly associated with the virologic endpoint. A viral rebound rate >10% was observed in patients treated with single PI (14.7%) or boosted PI (11.7%) up to an adherence rate of 95%, whereas a similar (17.6%) rebound rate was observed only in NNRTI-treated patients with very low adherence (<55%). After adjustment for other baseline predictors of adherence, patients on NNRTIs showed a higher adherence rate than those on PIs but not higher than those on boosted PIs. The same adherence rate did not have the same result, in terms of virologic rebound, in patients on the same HAART for shorter or longer periods of time. Overall, the risk of virologic rebound for patients with >95% adherence rate was 6.2% in the first 6 months of therapy, lowered to 5.0% in the following 6 months, and was 3.2% thereafter. The risk of selecting for resistance-inducing viral mutation for NNRTI-treated patients was higher (4.9%) at very low adherence rates (<75%); the opposite was true for single PI-treated patients (4.2% for adherence >95%). Boosted PI-treated patients showed an intermediate pattern, even if at a much lower level of risk. CONCLUSION: Low adherence is a major determinant of virologic failure, however different therapies have different adherence cutoffs determining a significant increment of risk.

Propionibacterium endocarditis: a case series from the International Collaboration on Endocarditis Merged Database and Prospective Cohort Study.

Propionibacterium species are occasionally associated with serious systemic infections such as infective endocarditis. In this study, we examined the clinical features, complications and outcome of 15 patients with Propionibacterium endocarditis using the International Collaboration on Endocarditis Merged Database (ICE-MD) and Prospective Cohort Study (ICE-PCS), and compared the results to 28 cases previously reported in the literature. In the ICE database, 11 of 15 patients were male with a mean age of 52 y. Prosthetic valve endocarditis occurred in 13 of 15 cases and 3 patients had a history of congenital heart disease. Clinical findings included valvular vegetations (9 patients), cardiac abscesses (3 patients), congestive heart failure (2 patients), and central nervous system emboli (2 patients). Most patients were treated with beta-lactam antibiotics alone or in combination for 4 to 6 weeks. 10 of the 15 patients underwent valve replacement surgery and 2 patients died. Similar findings were noted on review of the literature. The results of this paper suggest that risk factors for Propionibacterium endocarditis include male gender, presence of prosthetic valves and congenital heart disease. The clinical course is characterized by complications such as valvular dehiscence, cardiac abscesses and congestive heart failure. Treatment may require a combination of medical and surgical therapy.

Age at infection affects the long-term outcome of transfusion-associated chronic hepatitis C.

Before the introduction of hepatitis C virus (HCV) screening for blood donors, the risk of acquiring HCV infection as a result of a transfusion was about 10%. The aim of this study was to assess the frequency and rate of progression to cirrhosis in patients with transfusion-associated chronic HCV infection and identify possibly negative prognostic factors. Of 2477 consecutive patients with clinical or laboratory evidence of liver disease, 392 (16%) were anti-HCV- and HCV-RNA-positive, had anamnestic evidence of a single and precisely dated transfusion event, and showed no other causes of chronic liver disease; 268 (68%) underwent ultrasound-guided liver biopsy and were enrolled in the study. After a mean interval of 18.4 years, 54 patients (20.1%) had cirrhosis, which multivariate analysis showed to be independently associated with the duration of follow-up, age at infection and at the time of liver biopsy, and serum alanine aminotransferase levels at biopsy. The time necessary to have a 50% probability of developing cirrhosis in patients aged 21-30, 31-40, and more than 40 years was 33, 23, and 16 years, respectively. In comparison with those aged 20 years or less at infection, the risk ratio of developing cirrhosis over a period of 30 years for patients aged 21-30 and at least 31 years at infection was, respectively, 4.51 (95% confidence interval, 1.03-19.76) and 12.29 (95% confidence interval, 3.06-49.40). In patients with transfusion-associated chronic hepatitis C, the risk of cirrhosis is related to age at infection and disease activity. Our findings suggest that an aggressive therapeutic approach should be adopted in patients infected by HCV at an older age to prevent the progression to end-stage liver disease.