The role of tenofovir in preventing and treating hepatitis B virus (HBV) reactivation in immunosuppressed patients. A real life experience from a tertiary center

INTRODUCTION/AIM

Patients who present HBV reactivation during immunosuppressive treatment are prone to develop life threatening decompensation of the liver function, therefore prophylaxis and treatment are strongly recommended. So far there are no data regarding the role of tenofovir in this context. Therefore, the aim of our study was to describe our "real life" experience with the use of tenofovir (TDF) in patients who underwent immunosuppressive treatment.

RESULTS

38 patients with immunosuppression received antiviral treatment with tenofovir (25 patients as prophylaxis and 13 patients as treatment of HBV reactivation). In all 25 patients in whom prophylactic treatment with tenofovir was administered no HBV flare occurred during immunosuppression and the levels of serum HBV-DNA became or remained undetectable during the follow up period (mean follow up 17.2 months, range 6-54). One patient experienced HBsAg seroconversion. In the 13 patients who exhibited HBV reactivation TDF treatment resulted in complete biochemical and virological response within 6 months except two patients with high pretreatment HBV-DNA levels who became HBV-DNA negative at 9 months. No exacerbation of liver disease or liver related death has been observed. One patient who presented with decompensated cirrhosis during HBV reactivation returned into a compensated state after treatment. No side effects of tenofovir have been documented.

CONCLUSION

Tenofovir seems to be highly effective and safe in the prophylaxis and rescue treatment of HBV reactivation in patients who receive immunosuppression therapy.

Donut-shaped chambers for analysis of biochemical processes at the cellular and subcellular levels

In order to study cell-cell variation with respect to enzymatic activity, individual live cell analysis should be complemented by measurement of single cell content in a biomimetic environment on a cellular scale arrangement. This is a challenging endeavor due to the small volume of a single cell, the low number of target molecules and cell motility. Micro-arrayed donut-shaped chambers (DSCs) of femtoliter (fL), picoliter (pL), and nanoliter (nL) volumes have been developed and produced for the analysis of biochemical reaction at the molecular, cellular and multicellular levels, respectively. DSCs are micro-arrayed, miniature vessels, in which each chamber acts as an individual isolated reaction compartment. Individual live cells can settle in the pL and nL DSCs, share the same space and be monitored under the microscope in a noninvasive, time-resolved manner. Following cell lysis and chamber sealing, invasive kinetic measurement based on cell content is achieved for the same individual cells. The fL chambers are used for the analysis of the same enzyme reaction at the molecular level. The various DSCs were used in this proof-of-principle work to analyze the reaction of intracellular esterase in both primary and cell line immune cell populations. These unique DSC arrays are easy to manufacture and offer an inexpensive and simple operating system for biochemical reaction measurement of numerous single cells used in various practical applications.

The usefulness of transient elastography in the assessment of patients with HBeAg-negative chronic hepatitis B virus infection

Histological severity is often mandatory for the management of HBeAg-negative chronic HBV patients. We evaluated the performance of transient elastography (TE) in this setting. We included 357 untreated HBeAg-negative patients with ≥ 1 reliable liver stiffness measurement (LSM-kPa) by TE: 182 inactive carriers with HBV-DNA < 2000 (n = 139) or 2000-19 999 IU/mL (n = 43) and 175 patients with chronic hepatitis B (CHB). In carriers, HBV-DNA > 2000 and/or LSM > 6.5 were considered as biopsy indications. LSMs did not differ between carriers with low and high viremia, but were lower in carriers than in patients with CHB (5.8 ± 1.7 vs 9.0 ± 5.6, P < 0.001) offering moderate differentiation between these two groups (AUROC: 0.705). LSMs did not change significantly in carriers after 16 (12-24) months. In carriers with a liver biopsy, Ishak's staging scores were similar between cased with low and high viremia but higher in cases with LSM > 6.5 than ≤ 6.5 kPa. Moderate fibrosis (stages: 2-3) was detected in 0/10 carriers with only HBV-DNA > 2000 IU/mL, 2/10 (20%) carriers with only LSM > 6.5 and 5/10 (50%) carriers with both HBV-DNA > 2000 and LSM > 6.5 (P = 0.009). In patients with CHB, LSMs correlated significantly with grading and staging scores and offered excellent accuracy for ≥ moderate, ≥ severe fibrosis or cirrhosis (AUROC ≥ 0.919-0.950). TE can be helpful for the noninvasive assessment of HBeAg-negative chronic HBV patients. In conclusion, LSMs offer excellent accuracy for fibrosis severity in HBeAg-negative patients with CHB and can identify carriers with high risk of moderate fibrosis, which may be present in up to 35% of carriers with LSM > 6.5 kPa and 50% of carriers with LSM > 6.5 kPa and HBV-DNA > 2000 IU/mL.

Cirrhosis but not neutropenia is associated with the development of infection in patients with chronic hepatitis C undergoing treatment with pegylated interferon-alpha and ribavirin

Peginterferon-alpha (PegIFNa) frequently causes neutropenia, mainly due to bone marrow suppression. The aim of this study was to explore factors that are associated with infections during antiviral treatment. We analysed data from 275 chronic hepatitis C (CHC) patients with compensated liver disease who underwent 318 courses of PegIFNa and ribavirin. Neutropenia was defined as neutrophils <1000 cells/μL. Mean leucocytes count significantly decreased from baseline to treatment nadir (7081 ± 2182 vs 3293 ± 1331 cells/μL, P < 0.001), while neutropenia was observed in 32% during treatment. Thirty-one infections were observed. The incidence rate for infection was assessed at 1.46 infections per 100 person-months of therapy. The hazard rate for infection did not correlate with the neutrophils' nadir or the decrease in white blood cells. In multivariate Cox's regression analysis, cirrhosis was the only factor that was significantly associated with the occurrence of infection. Our data show that the development of bacterial infections during treatment with PegIFNa and ribavirin in patients with compensated CHC is not associated with reduction or the nadir of white cells or neutrophil counts. Baseline cirrhosis is the only factor related with infection during treatment. The common practice of dose adjustment or discontinuation of interferon should be revised; careful assessment of liver damage before therapy and close monitoring during therapy are essential in all patients receiving interferon-based regimes, to minimize the detrimental consequences of infections.

Checkerboard self-patterning of an ionic liquid film on mercury

Å-resolution studies of room temperature ionic liquid (RTIL) interfaces are scarce, in spite of their long-recognized importance for the science and many applications of RTILs. We present an Å-resolution x-ray study of a Langmuir film of an RTIL on mercury. At low (high) coverage [90 (50) Å2/molecule] a mono-(bi)layer of surface-parallel molecules is found. The molecules self-assemble in a lateral ionic checkerboard pattern, unlike the uniform-charge, alternate-ion layers of this RTIL at its bulk-solid interface. A 2D-smectic order is found, with molecules packed in parallel stripes, forming long-range order normal to, but none along, the stripes.

Unifying interfacial self-assembly and surface freezing

X-ray investigations reveal that the monolayers formed at the bulk alkanol-sapphire interface are densely packed with the surface-normal molecules hydrogen bound to the sapphire. About 30-35 °C above the bulk, these monolayers both melt reversibly and partially desorb. This system exhibits balanced intermolecular and molecule-substrate interactions which are intermediate between self-assembled and surface-frozen monolayers, each dominated by one interaction. The phase behavior is rationalized within a thermodynamic model comprising interfacial interactions, elasticity, and entropic effects. Separating the substrate from the melt leaves the monolayer structurally intact.

Surface plasmon based thermo-optic and temperature sensor for microfluidic thermometry

We report on a noninteracting technique for the thermal characterization of fluids based on surface plasmon resonance interrogation. Using liquid volumes less than 20 μl, we have determined the materials' thermo-optic coefficients with an accuracy of better than 1×10(-5) °C(-1) and demonstrated temperature sensing with an accuracy of 0.03 °C. The apparatus employs a low-power probe laser, requiring only a single wavelength, polarization, and interrogation angle for accurate characterization. The device is particularly suited for precise diagnostics of liquids and gases within microfluidic systems and may also be readily integrated into a variety of lab-on-chip platforms, providing rapid and accurate temperature diagnostics.

Crystallinity of the double layer of cadmium arachidate films at the water surface

A crystalline counterionic layer at the interface between an electrolyte solution and a charged layer of insoluble amphiphilic molecules was observed with grazing incidence synchrotron x-ray diffraction. Uncompressed arachidic films spread over 10(-3) molar cadmium chloride solution (pH 8.8) spontaneously form crystalline clusters with coherence lengths of approximately 1000 angstroms at 9 degrees C. Ten distinct diffraction peaks were observed, seven of which were attributed to scattering only from a crystalline Cd(2+) layer and the other three to scattering primarily from the arachidate layer. The reflections from the Cd(2+) layer were indexed according to a 2 x 3 supercell of the arachidate lattice with three Cd(2+) ions per cadmium unit cell.

Surface layering at the mercury-electrolyte interface

X-ray reflectometry reveals atomic layering at a liquid-liquid interface--mercury in a 0.01 M NaF solution. The interface width exceeds capillary wave theory predictions and displays an anomalous dependence on the voltage applied across it, displaying a minimum positive of the potential of zero charge. The latter is explained by electrocapillary effects and an additional intrinsic broadening of the interface profile, tentatively assigned to polarization of the conduction electrons due to the electric field of the electrochemical double layer at the interface.

The Influence of Different Cultivating Conditions on Polymorphonuclear Leukocyte Apoptotic Process In Vitro, II: Ultrastructural Characteristics of PMN Populations Incubated with Proteinase 3 Anti-neutrophil Autoantibodies

The present study shows the effects of proteinase 3 anti-neutrophil cytoplasmic autoantibodies (PR3 ANCA) on polymorphonuclear leukocytes (PMN) apoptotic processes in vitro. The results are part of a generalized morphological analysis of 3 identical experiments on the influence of different cultivating conditions on the apoptotic processes. As controls, the authors use the results on spontaneous PMN apoptosis (Guejes L, Zurgil N, Deutsch M, Gilburd B, Shoenfeld Y. Ultrastruct Pathol. 2003;27: 23-32) and PMN populations incubated with normal human IgG. Interaction of PR3 ANCA with the target antigen proteinase 3 (PR3) is one of the crucial pathogenic factors in Wegener granulomatosis (systemic autoimmune vasculitis). Following 40min and 12h incubation, PMN populations were evaluated by light microscopy, transmission electron microscopy, and immunogold electron microscopy. Twelve-hour cultures, either control or incubated with PR3 ANCA, contained different cell forms ranging from normal cells to cells at the final stages of apoptosis. Neutrophils at the state of complete manifestation of apoptotic phenotype were analyzed and compared. Three morphologically distinct apoptotic cell lines were characteristic for all PMN populations studied, regardless of cultivating conditions. As in spontaneous apoptosis, these cell lines are code-named "first," "second," and "third." The present study has shown, firstly, that in the presence of PR3 ANCA, all 3 apoptotic lines were modified or altered. Secondly, the modifications or alterations of apoptotic cell lines effected by PR3 ANCA are specific for each cell line: the "first" line is characterized by intensification and modification of activation; the "second" by vacuolized cell forms; and the "third" by pronounced lytic alterations of the nuclei, while the cytoplasm is fully identical to that of control cell lines.

Langmuir films of chiral molecules on mercury

Homo- and heterochiral Langmuir films of a chiral derivative of stearic acid are studied in situ on the surface of liquid mercury as a function of surface coverage by surface tensiometry and surface-specific synchrotron X-ray diffraction and reflectivity. A transition from a phase of surface-parallel molecules to a phase of standing-up molecules is found. The former shows no surface-parallel long-range order. The standing-up phase of both homochiral and heterochiral compositions exhibit long-range order. However, the former has an oblique unit cell with parallel molecular planes, and the later has a centered rectangular unit cell with a herringbone molecular packing. For both cases, the standing-up molecules are tilted by 44 degrees from the surface normal and pack at a density of 19.5 A(2)/molecule in the plane normal to the molecular long axis. Important differences are found, and discussed, between this behavior and that of a Langmuir film of the nonchiral stearic acid on mercury.