Sònia López

Mitochondrial Effects of HIV Infection on the Peripheral Blood Mononuclear Cells of HIV-Infected Patients Who Were Never Treated with Antiretrovirals

To investigate the effects of HIV infection on mitochondrial DNA (mtDNA) content and other mitochondrial parameters, we used peripheral blood mononuclear cells (PBMCs) from 25 asymptomatic antiretroviral-naive human immunodeficiency virus (HIV)-infected patients and from 25 healthy control subjects. HIV-infected patients had significant decreases in mtDNA content (decrease, 23%; P<.05) and in the activities of mitochondrial respiratory chain (MRC) complex II (decrease, 41%; P<.001), MRC complex III (decrease, 38%; P<.001), MRC complex IV (decrease, 19%; P=.001), and glycerol-3-phosphate dehydrogenase (decrease, 22%; P<.001), along with increased lipid peroxidation of PBMC membranes (P=.007). Therefore, HIV infection is associated not only with mtDNA depletion, but also with extensive MRC disturbances and increased oxidative damage.

Effect of smoking cessation on mitochondrial respiratory chain function.

Objective. Chronic smoking has been associated with diverse mitochondrial respiratory chain (MRC) dysfunction in lymphocytes, although inhibition of complex IV activity is the most consistent and relevant finding. These mitochondrial abnormalities have been proposed to contribute to pathogenesis of diseases associated with tobacco consumption. We assessed MRC function in peripheral lymphocytes from heavy smokers after cessation in smoking habit. Patients and Methods. We studied MRC function from peripheral lymphocytes of 10 healthy chronic smoker individuals (age 43±6 years; 50% women) before cessation of tobacco consumption (t0), and 7 (t1) and 28 (t2) days after cessation. Smoking abstinence was ascertained by measuring carboxyhemoglobin levels and carbon monoxide (CO) concentration in exhaled breath. Ten healthy nonsmoker individuals matched by age and gender were used as controls. Lymphocytes were isolated by Ficolls gradient, and protein content was determined by Bradfords technique. MRC function was studied through double means: 1) individual enzyme activities of complex II, III, and IV were analyzed by means of spectrophotometry; 2) oxygen consumption was measured polarographically using pyruvate, succinate, and glycerol-3-phosphate (complex I, II, and III substrates, respectively) after lymphocyte permeabilization. Enzyme and oxidative activities were corrected by citrate synthase activity. Results. Smokers showed a significant decrease in complex IV activity (p=0.05) and also in respiration of intact lymphocytes (p=0.05) compared to controls. Eight chronic smokers remained abstinent during the study. Smoking cessation was associated with a significant recovery of complex IV (p=0.01) and complex III (p=0.05) activities. Oxidative activities did not show any change during the study. Conclusion. Chronic smoking is associated with a decrease of complex IV and III activities of MRC, which return to normal values after cessation of tobacco smoking.

Mitochondrial respiratory chain in brain homogenates: activities in different brain areas in patients with Alzheimer’s disease

Background and aims: The potential influence of impaired oxidative metabolism in the modulation of manifestations in sporadic Alzheimer’s disease (AD) has attracted much attention in the last 50 years. Unfortunately, many clinical and experimental results aiming at proving this hypothesis are still controversial. The aim was to study the enzymatic activities of respiratory chain (RC) complexes I through V in three brain areas of a group of patients with definite AD, and to compare the results with a group of normal brains. We simultaneously assessed the lipid peroxidation of the samples as a measure of free radical damage. Methods: The specific activity of the individual complexes of the RC was measured spectrophotometrically, and the loss of cis-parinaric acid fluorescence was used to determine the chemical process of lipid peroxidation. Results: We were not able to detect differences in any of the analyzed RC enzymatic activities, or in the level of lipid peroxidation between patients with AD and controls. Instead, differences were found in the number of mitochondria and in the intrinsic enzymatic activities of complexes III and IV in various brain areas. Conclusions: Spectrophotometric enzymatic analyses of respiratory complexes in brain homogenates do not support the primary contribution of mitochondrial RC dysfunction in the pathogenesis of AD.

Reactivación del virus de la hepatitis B en pacientes tratados con rituximab: incidencia y factores de riesgo

Hepatitis B virus (HBV) reactivation after chemotherapy regimens is a well-known complication. The incidence and risk factors for HBV reactivation remain to be elucidated. We aimed to determine the incidence and risk factors for HBV reactivation in patients receiving rituximab, and the potential role of the cumulative rituximab dose in HBV reactivation. We retrospectively reviewed 320 patients receiving rituximab in our hospital. Of these, 42 (13.12%) had serological markers of hepatitis B. During follow-up, 21% (9/42) had HBV reactivation. Risk factors for reactivation were HBsAg positivity (p < 0.05), isolated anti-HBc positivity (p < 0.05), marginal zone lymphoma, and Mantle cell lymphoma (p < 0.05). The median rituximab dose tended to be higher in patients with reactivation (p = 0.06).

Seroprevalencia de hepatitis C en población con factores de riesgo del suroeste de la Comunidad de Madrid

INTRODUCTIONnThe estimated seroprevalence of hepatitis C virus (HCV) in Spain is 1.7%, but is much higher in the at-risk population. The most efficient national screening strategy is unclear.nnnAIMSnTo estimate the prevalence of HCV among the at-risk population seen in primary care (PC), and to determine their epidemiological profile.nnnMATERIALS AND METHODSnCross-sectional descriptive prevalence study that included adult patients with risk factors for HCV infection seen in PC in the southwest Madrid region between 2010 and 2012.nnnRESULTSnA total of 158 patients (men=51.3%), mean age 46 years (SD=16.6), were included. The most common risk factors were hypertransaminasaemia (44.3%) and major surgery (13.3%). Immigration, unsafe sexual practices, and tattoos or body piercing were more prevalent in patients younger than 45 years of age. Fifteen patients (9.5%) were positive for anti-HCV; 9 of these (5.7%) were HCV-ARN positive. Of the positive patients, 4 (44.4%) had significant fibrosis at diagnosis (F3-F4). Male patients had a higher rate of positive anti-HCV results (13.8 vs. 5.3%; P=.072), as did patients older than 45 years of age (12.8 vs. 6.3%; P=.167). Intravenous and intranasal drug use were associated with a higher rate of positive anti-HCV results (50 vs. 8.5%; P=.005 and 66.7 vs. 8.4%; P=.001, respectively).nnnCONCLUSIONSnPatients with risk factors for HCV infection have high seroprevalence. Screening programmes must therefore be implemented to detect HCV infection in this population in PC.