Impact of antiretroviral treatment on (13) C-methionine metabolism as a marker of hepatic mitochondrial function: a longitudinal study.

OBJECTIVES: Uncontrolled viral replication and antiretroviral treatment (ART) may independently contribute to hepatic mitochondrial toxicity. The present study was designed to explore the longitudinal effects of treatment modifications on hepatic mitochondrial function by means of noninvasive (13) C-methionine breath test (MeBT) diagnostics. METHODS: A total of 113 HIV-infected patients underwent two consecutive MeBTs over an interval of 11.8±3.5 months. Forty-nine patients remained on stable ART or no therapy; 28 participants switched ART; 27 patients (re)initiated ART, and nine individuals underwent a structured treatment interruption (STI) of ART between MeBTs 1 and 2. Breath test results were expressed as cumulative percentage dose of (13) CO(2) recovered after 1.5 h test time (cPDR(1.5h) ). RESULTS: Initiation of ART in treatment-naïve individuals and patients on STI was associated with a significant improvement of hepatic mitochondrial function (P<0.05). Cessation of ART or a prolonged delay in initiating therapy in treatment-naïve patients in turn led to a significant decline of (13) C-exhalation compared with baseline (P<0.05). A marked increase in (13) C-exhalation was observed in individuals who switched from stavudine or ddI to tenofovir or abacavir (+170%; P<0.001), while no differences between MeBTs 1 and 2 were found in individuals on ART who had remained on stable regimens or in those who changed a protease inhibitor (PI) or nonnucleoside reverse transcriptase inhibitor (NNRTI) component. CONCLUSION: The present data suggest that hepatic mitochondrial function in HIV disease is a dynamic process with a high regenerative capacity and highlight the pathogenic relevance of HIV replication. Our findings suggest that modern ART per se does not negatively impact hepatic mitochondrial function.

Disease- and treatment-related predictors of hepatic mitochondrial dysfunction in chronic HIV infection assessed by non-invasive (13)C-methionine breath test diagnostic.

OBJECTIVES: An increasing proportion of deaths among human immunodeficiency virus (HIV)-infected persons are due to hepatic complications. Hepatitis coinfection, antiretroviral treatment and co-occurrence of metabolic risk factors contribute to hepatic mitochondrial damage manifesting in hepatic steatosis and steatohepatitis. The aim was to assess disease- and treatment-related predictors on hepatic mitochondrial dysfunction in HIV infection by means of a new (13)C-methionine breath test (MeBT). PATIENTS AND METHODS: 148 HIV positive individuals with and without antiretroviral treatment (ART) [44 therapy-naives; 89 patients on combination ART and 15 patients on structured treatment interruption (STI)] and 20 HIV-negative controls were studied prospectively by MeBT. RESULTS: A decay of (13)C-methionine metabolism, expressed as cumulated percentage dose recovered over 1.5h (cPDR(1.5h)), in the subgroups of treatment-naives and patients on STI compared to controls was detected (cPDR(1.5h): 3.4 +/- 1.3% and 4.0 +/- 2.4% vs. 6.3 +/- 1.2%; p<0.01). Multivariate analyses including metabolic, treatment- and disease-related variables showed that antiretroviral treatment with stavudine, didanosine or zalcitabine and treatment-naivety were best predictors of a reduced MeBT result (cPDR(1.5h)) (beta = -0.56 and -0.50, p<0.05). CD4 count had only a minor association (beta = 0.15, p<0.05). No other variable including disease and treatment duration was associated with MeBT outcome. These factors explained 39% of the variance of MeBT results (p<0.05). CONCLUSIONS: Therapy naivety and treatment with d-drugs were the best predictors of poor MeBT outcome. MeBT may be proposed as a feasible, noninvasive diagnostic instrument for clinical assessment of hepatic mitochondrial function and early detection of drug-induced mitochondriotoxity in chronic HIV infection.

Longitudinal effects of hepatitis C virus treatment on hepatic mitochondrial dysfunction assessed by C-methionine breath test.

BACKGROUND: Hepatitis C virus (HCV) infection is characterized by remarkable levels of oxidative stress induced by virus interactions with hepatic mitochondria. AIM: To examine hepatic mitochondrial function in HCV-infected patients assessed by a non-invasive (13)C-methionine breath test (MeBT) and to explore longitudinal effects of antiviral treatment. METHODS: Twenty-one patients with chronic hepatitis C undergoing antiviral treatment with pegIFNalpha and ribavirin and 20 healthy controls were studied. MeBT was performed at baseline, week 12, end-of-treatment and after 24 weeks of follow-up in all patients with early virological response (n = 15). RESULTS: Twelve patients achieved sustained virological response (SVR); three patients relapsed for HCV-RNA replication. Cumulative percentage 13C-exhalation (cPDR(1.5h)) was significantly decreased in HCV-infected individuals compared to controls irrespective of genotype and fibrosis stage (P < 0.001). Antiviral treatment induced a further decay in cPDR(1.5h) (P < 0.01). After treatment cessation, 13C-exhalation returned at least to baseline values in all patients. SVR was even associated with a mean cPDR(1.5h) increase of 70% compared to baseline. CONCLUSIONS: Hepatitis C virus infection and antiviral treatment synergistically impair hepatic mitochondrial function, which may return to normal after sustained virus elimination. MeBT may be a valuable diagnostic instrument for monitoring hepatic mitochondrial function in particular in patients with mitochondrial comorbidities.

Complex extra-intestinal complications of ulcerative colitis in a patient with alpha1-antitrypsin deficiency.

Ulcerative colitis (UC) can manifest with a variety of extra-intestinal disorders frequently affecting the skin, joints, and liver. An aetiologic role of alpha1-antitrypsin deficiency in chronic inflammatory bowel disease has recently been suggested. We report a patient with UC and alpha1-antitrypsin deficiency who presented with disseminated cutaneous leucocytoclastic vasculitis clinically appearing with target-like purpuric patches and haemorrhagic oedemas. In addition, he displayed acute haemorrhage of the eyes and the respiratory tract consistent with a systemic vasculitic process. Moreover, he had autoimmune haemolytic anaemia. Systemic vasculitides, such as Wegener's granulomatosis, Churg-Strauss syndrome, and microscopic polyangiitis, could widely be excluded. Systemically administered glucocorticosteroids and azathioprine led to dramatic improvement of extra-intestinal symptoms. On the basis of alpha1-antitrypsin deficiency and UC, the present patient likely developed severe systemic vasculitis with multi-organ involvement. UC should at times be viewed within the context of a more generalized immune imbalance affecting multiple organs, and not as an isolated pathological entity. Testing for alpha1-antitrypsin deficiency in UC patients may detect individuals at higher risk of severe extra-intestinal involvement.

Vascular endothelial growth factor (VEGF164) ameliorates intestinal epithelial injury in vitro in IEC-18 and Caco-2 monolayers via induction of TGF-beta release from epithelial cells.

OBJECTIVE: VEGF is a glycoprotein with various (e.g. angiogenic) activities. So far, research has focused on its angiogenic properties. VEGF receptors are localized on epithelial cells of patients with inflammatory bowel disease (IBD) and also on Caco-2 and IEC-18 cells. Our aim was to evaluate the role of VEGF on intestinal epithelial cell (IEC) migration and proliferation by utilizing an established in vitro model. METHODS: IEC-18 and Caco-2 monolayers were wounded with a razor blade as described previously. Cells were incubated in medium w/o rat VEGF(164). After 24 h, migration was assessed by counting cells across the wound edge. Migration was blocked with neutralizing TGF-beta(1) antibodies. IEC proliferation was assessed using the MTT (3-[4, 5-Dimethylthiazol-2-yl]-2, 5-diphenyl-tetrazolium bromide) test. Semi-quantitative changes of the TGF-beta(1) mRNA expression were evaluated before and after stimulation of the cells with VEGF(164) by RT-PCR. Statistical analysis was performed with ANOVA and the Wilcoxon test. RESULTS: VEGF(164) significantly induced epithelial cell migration in Caco-2 and IEC-18 cells compared to control. TGF-beta(1) antibodies completely abolished this VEGF-induced cell migration. TGF-beta(1) mRNA significantly increased in IEC-18 and Caco-2 cells after stimulation with VEGF. VEGF significantly inhibited epithelial cell proliferation in IEC-18 and in Caco-2 cells, indicating that the observed effects on cell migration were not due to any proliferate effects. CONCLUSION: VEGF effects on epithelial cell migration play an important part in epithelial cell restitution by maintaining mucosal homeostasis after mucosal injury. This effect is mediated by TGF-beta(1). Our results obtain another possible role for increased VEGF levels in the intestinal mucosa of patients with IBD as reported recently by others.

Predictors of gastric emptying in Parkinson's disease.

Predictors of gastric emptying (GE) in patients with idiopathic Parkinson's disease (PD) of a solid and liquid meal are not well defined. For measurement of GE 80 patients with PD were randomly assigned to receive either a solid meal (250 kcal) containing 13C-octanoate (n = 40) or a liquid meal (315 kcal) with 13C-acetate (n = 40). All patient groups were off medication affecting motility and were matched for age, gender, body mass index, disease duration and severity, using Unified Parkinson's Disease Rating Scale (UPDRS). Gastric emptying was compared with a healthy control group (n = 40). Multiple regression analysis was used to determine predictors of gastric emptying. Exactly 88% and 38% of PD patients had delayed GE of solids and liquids respectively. Solid and liquid emptying was similar in women and men. There were no differences in GE in PD patients < 65 years of age when compared with patients > or = 65 years. Multiple regression analysis showed that motor handicaps such as rigour and action tremor are independent predictors of solid GE (r = 0.68, P < 0.001). The severity of motor impairment, but not any other neurological symptom, as assessed by UPDRS is associated with gastroparesis in PD and solid emptying is more likely to be delayed.

Human PACAP response gene 1 (p22/PRG1): proliferation-associated expression in pancreatic carcinoma cells.

p22/PACAP response gene-1 (PRG1) is a novel rat early response gene expressed during induction of proliferation and stress response. In humans, a homolog of p22/PRG1, designated IEX-1/DIF-2, exists, yet the exact function of this gene remains elusive. To characterize the expression of p22/PRG1 in human cancers, we analyzed the expression of p22/PRG1 in the human pancreatic carcinoma cell lines 818-4, PT45, and PancTu1. Serum or growth factors, like epidermal growth factor (EGF) and hepatocyte growth factor (HGF), rapidly and transiently induced transcription of p22/PRG1 in these cells, correlating with the mitogenic response. Treatment with TNF-alpha was followed by a rapid increase of p22/PRG1 messenger RNA (mRNA) levels in PT45 and Panc-Tul cells, which proliferate in the presence of TNF-alpha, but not in 818-4 cells, which are growth-inhibited when treated with TNF-alpha. Our findings suggest that human p22/PRG1 is expressed in various pancreatic carcinoma cells as a growth-associated early response gene.