Liver inflammatory cells, apoptosis, regeneration and stellate cell activation in non-alcohol steatohepatitis

Background, The pathogenesis of non-alcoholic steatohepatitis remains unclear from several points of view. Minimal diagnostic criteria are still not defined. Aim. To gather information useful for diagnosis and to improve the understanding of pathogenic mechanisms.

Patients. A series of 14 patients with non-alcoholic steatohepatitis, identified among liver outpatients, were paired for age, sex and alanine amino transferase values with 14 patients with hepatitis C virus infection without steatosis.

Methods. Clinical, biochemical and immunohistological examination, including characterisation of inflammatory cell population, evaluation of type 111 collagen and tenascin deposition, activation of stellate cells, hepatocellular apoptosis and proliferation.

Results. Patients with non-alcoholic steatohepatitis were more frequently obese, had higher triglyceride concentrations and lower gamma-globulins. T lymphocytes outnumbered polymorphonuclear cells, both in hepatitis C and in steatohepatitis, with a larger number of CD8 lymphocytes in patients with viral hepatitis but a comparable number of granulocytes. This resulted in a higher granulocytes to T cells ratio in steatohepatitis, possibly making these cells more easily detectable in spite of similar absolute numbers. Portal fibrosis and piecemeal necrosis were prevalent in hepatitis C virus infection, pericentral fibrosis was similar. Hepatocellular, apoptosis and proliferation as well as stellate cell activation were less relevant in steatohepatitis than in hepatitis C virus infection in spite of similar alanine amino transferase levels.

Conclusions. These data provide a possible explanation for the relatively low tendency to progression of non-alcoholic steatohepatitis in most patients despite increased alanine amino transferase and suggest that non-death-related release of alanine amino transferase might occur in non-alcoholic steatohepatitis. This makes liver biopsy an essential part of the clinical setting supporting diagnosis, evaluation of severity and possibly definition of the evolutionary trend.     

Factors affecting the transduction of pluripotent hematopoietic stem cells: long-term expression of a human adenosine deaminase gene in mice

An amphotropic retroviral vector, LgAL(delta Mo + PyF101) containing a human adenosine deaminase (ADA) cDNA was used to optimize procedures for the lasting genetic modification of the hematopoietic system of mice. The highest number of retrovirally infected cells in the hematopoietic tissues of long-term reconstituted mice was observed after transplantation of bone marrow (BM) cells that had been cocultured in the presence of both interleukin-1 alpha (IL-1 alpha) and IL-3. A significantly lower number was detected when IL-1 alpha was omitted from such cocultures. The yield of cells that generate spleen colony-forming cells (CFU-S) in the BM of lethally irradiated recipients (MRA-CFU-S) significantly improved on inclusion of the adherent cell fraction of cocultures in the transplant. Retroviral integration patterns in MRA-CFU-S-derived spleen colonies showed that an MRA-CFU-S can produce many CFU-S during BM regeneration. Expression of hADA was detected in the circulating white blood cells of long-term reconstituted animals, demonstrating that the LgAL(delta Mo + PyF101) vector is capable of directing the sustained expression of hADA, and in approximately 35% of the transduced MRA-CFU-S-derived spleen colonies. These results should facilitate the development of gene therapy protocols for the treatment of severe combined immunodeficiency caused by a lack of functional ADA.     

Chronic rejection after liver transplantation: Opening the Pandora’s box

Chronic rejection (CR) of liver allografts causes damage to intrahepatic vessels and bile ducts and may lead to graft failure after liver transplantation. Although its prevalence has declined steadily with the introduction of potent immunosuppressive therapy, CR still represents an important cause of graft injury, which might be irreversible, leading to graft loss requiring re-transplantation. To date, we still do not fully appreciate the mechanisms underlying this process. In addition to T cell-mediated CR, which was initially the only recognized type of CR, recently a new form of liver allograft CR, antibody-mediated CR, has been identified. This has indeed opened an era of thriving research and renewed interest in the field. Liver biopsy is needed for a definitive diagnosis of CR, but current research is aiming to identify new non-invasive tools for predicting patients at risk for CR after liver transplantation. Moreover, the minimization or withdrawal of immunosuppressive therapy might influence the establishment of subclinical CR-related injury, which should not be disregarded. Therapies for CR may only be effective in the “early” phases, and a tailored management of the immunosuppression regimen is essential for preventing irreversible liver damage. Herein, we provide an overview of the current knowledge and research on CR, focusing on early detection, identification of non-invasive biomarkers, immunosuppressive management, re-transplantation and future perspectives of CR.     

Incidence of new diabetic patients on dialysis in Piedmont,Italy: Major changes recorded over a 10-year period

Different incidence rates of new diabetic patients on dialysis are reported in various settings; although prevalence of this disease is often considered a marker of acceptance policy, rates are thought to be influenced also by genetic, epidemiological and other characteristics of a population (genetic composition, age distribution, lifestyle). Moreover, since features of a general population are often not stable (as in the setting analysed) changes at this level may have important reflections in the incidence of diabetics with end-stage renal disease (ESRD). In the region studied (Piedmont, northern Italy, about 4400 000 inhabitants, 20 dialysis centres, open acceptance since the mid-1970s, yearly information on 100% of patients, gathered by a Dialysis and Transplantation Registry) the incidence of diabetic patients with ESRD (389 cases recorded 1981–1990: 222 males, 167 females: mean age at start increasing from 55.5 years in 1981–1985 to 58.7 years in 1986–1990) differs according to age and sex. Incidence was higher in males, and rose from 6.23/year patients per million population (p.m.p.) in 1981–1982 to 12.88/year p.m.p. in 1989–1990, with a peak at age 60–69 (from 18.46/year p.m.p. in 1981–1982, to 46.12/year p.m.p. in 1989–1990). While relatively stable in the younger age groups from 1981 to 1990, incidence increased in the elderly (males age 70–79: 7.12/year p.m.p. in 1981–1982, 26.08/year p.m.p. in 1989–1990). As regards clinical and metabolic patterns, at the first update, in 1986–1990, 88.3% of diabetic patients were hypertensive or taking hypotensive drugs; albumin levels were below the normal range (<3.5 g/dl) in 30.3%; cholesterol levels were below the normal range (<150 mg/dl) in 16.15%. As regards entry criteria, creatinine clearances ranged from <1 to 14 ml/min (mean values at first update: 3.45±2.76 ml/min). In conclusion, presentation of diabetic patients with ESRD is changing. The stability of incidence in the younger age groups confirms the appropriateness of an open acceptance policy, at least for these ages. The increase in the elderly probably reflects the longer lifespan of diabetic patients in the overall population, while the influence of a hidden preselection must be further assessed. Since this cohort increasingly requires in-hospital high-tolerance treatment, future provision of dialysis needs must take into account the trend towards an increase in this high-risk elderly population.     

Cardiovascular Effects of a Single Slow Release Lanreotide Injection in Patients with Acromegaly and Left Ventricular Hypertrophy

In our study we assessed the effects of a single i.m. injection of slow-release Lanreotide (30 mg) (SR-L), a new long-acting somatostain analog, on circulating GH levels, baseline cardiac function (M-mode, 2D guided, doppler-echocardiographic study) and cardiopulmonary response to exercise (cycloergometric test, performed using a computer drived, electrically braked cycle ergometer), tested at baseline, after 7 and 14 days from the injection in 10 acromegalic patients (5 M, 5 F, mean age 57.7 ± 3.1 yrs, body mass index (BMI) 27 ± 0.8 kg/m², blood pressure 141 ± 6.5/82 ± 3 mmHg). SR-L administration decreased GH levels in acromegalic patients (mean±SEM) from 16.1 ± 6.9 to 10.8 ± 5.1 µg/L (p = 0.045) after 7 days and to 11.9 ± 5 µg/L (p = 0.078) after 14 days from the injection. Moreover, we observed a significant (p<0.05) decrease in systolic blood pressure and heart rate at the 7th (135 ± 6.1 vs 141 ± 6.5 mmHg, and 68 ± 2.1 vs 74 ± 2.1 bpm) and 14th (137 ± 6.2 vs 141 ± 6.5 mmHg, and 72 ± 2 vs 74 ± 2.1 bpm) day of the study with respect to the baseline values. After SR-L administration we also found an increase in ejection fraction (69 ± 2 vs 63 ± 2.3% at 7th day, p = 0.006; 65 ± 2.3 vs 63 ± 2.3% at the 14th day, p = 0.027) and shortening fraction (40.8 ± 1.8 vs 36.6 ± 1.9% at 7th day, p = 0.005; 38.7 ± 1.8 vs 36.6 ± 1.9% at the 14th day, p = 0.045). The positive acute cardiac response to SR-L injection was also demonstrated by the increase in A/E velocity ratios at 7th (1.14 ± 0.1 vs 0.98 ± 0.07, p = 0.016) and 14th (1.04 ± 0.08 vs 0.98 ± 0.07, p = 0.008) day of the study. After SR-L injection, exercise capacity and VO₂ at anaerobic thresold were also increased with respect to the baseline test: 61.1 ± 8.2 vs 38.9 ± 6.8 watts (p = 0.002) and 1012.4 ± 71.5 vs 915.3 ± 77.8 mL/min (p = 0.033) after 7 days, and 61.4 ± 7.2 vs 38.9 ± 6.8 watts (p = 0.002) and 1010.1 ± 62.5 vs 915.3 ± 77.8 mL/min (p = 0.010) after 14 days from the injection. In conclusion, these results suggest that in acromegalic patients: (1) SR-L causes a rapid improvement in baseline cardiac function and in cardiopulmonary performance during exercise in acromegaly; (2) the endocrine (decrease in GH levels) and echocardiographic responses to SR-L are maximal after 7 days from the injection, whereas the effect of SR-L on the exercise performance are longer lasting.     

Ischaemia-induced changes in canine cardiac sarcoplasmic reticulum

Effects of myocardial ischaemia on sarcoplasmic reticulum (SR) of dog hearts were investigated. Regional ischaemia was produced by occlusion of the left circumflex artery, and a microsomal fraction enriched in vesicles of SR was isolated from subendocardium (Endo) and subepicardium (Epi) of control and ischaemic areas of the heart. No significant changes occurred in ischaemic Epi. A loss of in vitro activities (ie calcium transport and ATPase) was found for SR from ischaemic Endo which paralleled the changes in the histology of the tissue. At 5 min of coronary occlusion, Ca2+ binding and Ca2+-ATPase activities of SR from ischaemic Endo were normal. A decrease in the activities of SR was first evident at 15 min after the occlusion, decreased further at about 30 min and remained at that level at 60 min of ischaemia. The maximal rate of Ca2+ uptake did not parallel the Ca2+-binding and Ca2+-ATPase activities. The degree of cAMP-dependent phosphorylation by endogenous and exogenous protein kinase was not different between SR from control and ischaemic areas. A participatory role of SR in the ischaemic impairment of left ventricular systolic and diastolic performance is discussed.     

HIV-1 matrix protein p17 enhances the proliferative activity of natural killer cells and increases their ability to secrete proinflammatory cytokines

We investigated the effects of human immunodeficiency type-1 virus (HIV-1) matrix protein p17 on freshly isolated and purified human natural killer (NK) cells. HIV-1 p17 increased the cytokines interleukin (IL) 2, IL-12 and IL-15, and induced natural killer cell proliferation, but not cytotoxicity. This effect was specific because it was abrogated by anti-p17 monoclonal antibody. Moreover, HIV-1 p17 enhanced the cytokine-induced production of tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma by NK cells. IL-4 downregulated IFN-gamma and TNF-alpha secretion in IL-2- and IL-15-treated NK cells. HIV-1 p17 restored the ability of NK cells to produce both cytokines when added to the cultures simultaneously with IL-4. The property of p17 to increase the production of TNF-alpha and IFN-gamma might be a mechanism used by HIV-1 to modulate the immune system to support its replication and spreading.