Liver fibrosis diagnosis by blood test and elastography in chronic hepatitis C: agreement or combination?

BACKGROUND

In chronic hepatitis C, the European Association for the Study of the Liver and the Asociacion Latinoamericana para el Estudio del Higado recommend performing transient elastography plus a blood test to diagnose significant fibrosis; test concordance confirms the diagnosis.

AIM

To validate this rule and improve it by combining a blood test, FibroMeter (virus second generation, Echosens, Paris, France) and transient elastography (constitutive tests) into a single combined test, as suggested by the American Association for the Study of Liver Diseases and the Infectious Diseases Society of America.

METHODS

A total of 1199 patients were included in an exploratory set (HCV, n = 679) or in two validation sets (HCV ± HIV, HBV, n = 520). Accuracy was mainly evaluated by correct diagnosis rate for severe fibrosis (pathological Metavir F ≥ 3, primary outcome) by classical test scores or a fibrosis classification, reflecting Metavir staging, as a function of test concordance.

RESULTS

Score accuracy: there were no significant differences between the blood test (75.7%), elastography (79.1%) and the combined test (79.4%) (P = 0.066); the score accuracy of each test was significantly (P < 0.001) decreased in discordant vs. concordant tests. Classification accuracy: combined test accuracy (91.7%) was significantly (P < 0.001) increased vs. the blood test (84.1%) and elastography (88.2%); accuracy of each constitutive test was significantly (P < 0.001) decreased in discordant vs. concordant tests but not with combined test: 89.0 vs. 92.7% (P = 0.118). Multivariate analysis for accuracy showed an interaction between concordance and fibrosis level: in the 1% of patients with full classification discordance and severe fibrosis, non-invasive tests were unreliable. The advantage of combined test classification was confirmed in the validation sets.

CONCLUSIONS

The concordance recommendation is validated. A combined test, expressed in classification instead of score, improves this rule and validates the recommendation of a combined test, avoiding 99% of biopsies, and offering precise staging.

[Results of scleral buckling for rhegmatogenous retinal detachment in phakic eyes]

PURPOSE

To report the results of primary scleral buckling in the treatment of uncomplicated rhegmatogenous retinal detachment in phakic eyes and to determine risk factors for failure.

PATIENTS AND METHODS

Retrospective study of 100 consecutive phakic eyes undergoing surgery for uncomplicated retinal detachment. All patients underwent cryopexy, scleral buckling with hard silicone explant type 287 and in selected cases, drainage of subretinal fluid and gas tamponnade with air or SF6.

RESULTS

The primary anatomic success rate was 84% and 99% respectively after one or multiple procedures. The causes of failure were new breaks (50%), proliferative vitreoretinopathy (31.2%) and malposition of the scleral buckle (18.8%). Mean visual acuity improved from 0.77±0.75 logMar to 0.21±0.19 logMar (P<0.00001). Predictive risk factors for failure included extent of the detachment beyond one quadrant and multiple breaks (P=0.03). Horseshoe tears had a worse prognosis than oral dialysis or atrophic round holes (P=0.04).

CONCLUSION

Scleral buckling remains safe and effective for the treatment of uncomplicated rhegmatogenous retinal detachments in phakic eyes, especially when the extent of the detachment was less than one quadrant or in the presence of a single tear, an atrophic round hole or an oral dialysis.

[Combined phacoemulsification and pars plana vitrectomy]

Cataract is frequently associated with vitreoretinal diseases. Moreover, cataract is also a constant complication of vitrectomy in patients over 50 years. Its occurrence may be very early, especially when internal tamponade is used. For these reasons, a combined procedure including phacoemulsification and vitrectomy accelerates functional rehabilitation of patients, avoiding the need for a second operation. Interventions, their tricks and indications, are described for epimacular membranes, macular holes, diabetic retinopathy and macular hematoma. Combined surgery is a safe and effective procedure whose results are comparable to those of sequential surgery.

[Which abnormalities can be detected in myopic peripheral retina?]

Vitreoretinal periphery in myopic eyes may present abnormalities whose frequency and severity are correlated with axial elongation of the eye: white-without-pressure, lattice degeneration, pigmentary degeneration, and paving stone degeneration. Sometimes one can find atrophic round holes, retinal breaks, or retinoschisis whose differential diagnosis with slow progressive retinal detachment can be made on the presence of an absolute field defect. The presence of peripheral vitreous strands, pigmentary migrations, holes, associated with extensive liquefaction of the central vitreous body and facial dysmorphy are symptomatic of Stickler syndrome often complicated with bilateral retinal detachments. Congenital hereditary retinoschisis should be raised in the presence of temporal and inferior bullous detachment of a thin inner layer of the retina associated with large multiple holes in a boy with poor vision and cystic macular changes. Examination of peripheral retina should be systematic after the age of 40 in myopic patients to specify the presence of abnormalities predisposing to retinal detachment. It is more important to inform the patient of posterior vitreous detachment or retinal detachment symptoms, a true emergency situation, rather than to suggest regular and repeated consultations in the nonsymptomatic eye.

Unrecognized dural puncture during epidural analgesia in obstetrics later confirmed by brain imaging

Accidental dural puncture is a well-recognized complication of obstetric epidurals that can potentially incapacitate the patient. Unrecognized dural puncture during epidural administration can lead to a delay in therapeutic intervention resulting in potentially serious complications. We report a case of a parturient who developed disabling intracranial hypotension and diplopia following accidental dural puncture during apparently uneventful epidural catheter insertion. Magnetic resonance neuroimaging was performed to confirm the diagnosis, and direct clinical management. We also discuss the role of neuroimaging in the investigation of postpartum headache.

FibroMeters: a family of blood tests for liver fibrosis

FibroMeters are blood tests for liver fibrosis with several specificities: two main diagnostic targets (fibrosis stage and area of fibrosis); adaptation to specific causes; and results confirmed by an expert system. Thus, FibroMeters comprise six different tests: one for staging and one for quantitation of liver fibrosis in each of the three main causes of chronic liver disease-chronic viral hepatitis, alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD). FibroMeters display a high overall diagnostic accuracy and are the only tests to correctly classify 100% of HCV patients without fibrosis or with cirrhosis. They have 90% predictive values in a higher proportion of patients than with other usual blood tests. A 90% correct classification is available in 100% of HCV patients with the following reliable diagnostic intervals: F0/1, F1/2, F2+/-1, F3+/-1. In real-life conditions, the reproducibility of FibroMeters is higher than that of liver biopsy or ultrasonographic elastometry. FibroMeters are robust tests with the most stable diagnostic performance across different centers. Optional tests are also available, such as a specific one for cirrhosis, which has a diagnostic accuracy of 93.0% (AUROC: 0.92) and a 100% positive predictive value for diagnosis of HCV cirrhosis. Determination by FibroMeters of the area of fibrosis - the only direct, non-invasive, quantitative measurement of liver fibrosis - are especially useful for following-up cirrhosis as it correlates well with clinical events. FibroMeters are also very accurate in HVB or HIV-HCV co-infected patients. The tests specific for ALD and NAFLD also have a high diagnostic accuracy (AUROCs: 0.96 and 0.94, respectively, for significant fibrosis).

Effects of piracetam on indices of cognitive function in a delayed alternation task in young and aged rats

The effects of piracetam (64, 128, and 256 mg/kg PO) on the performance of a delayed alternation in a Skinner Box were investigated. Test sessions consisted of 36 trials during which animals were first presented with a single lever (left or right) followed 5, 10, or 20 s later by two levers. A press on the lever opposite to that presented previously (nonmatching to sample) was rewarded. The number of correct responses and the reaction times to the one- and two-lever presentations were recorded. All animals received all treatments in a balanced order. Aged animals showed clear deficits on all three parameters. Piracetam was without effect on the performance of young animals but dose-dependently decreased the choice reaction times (two levers) in aged animals without affecting the other two parameters. These results suggest that piracetam does not affect short-term memory but may facilitate choice behavior in aged animals.

Regeneration of lesioned cholinergic septal neurons of the adult rat can be promoted by peripheral nerve grafts and a fibrin-fibronectin-containing matrix of peripheral regeneration chambers

Axonal regeneration of septal cholinergic neurons was examined after lesion of the septohippocampal pathway of the adult rat and implantation of tubes containing peripheral cellular or acellular substrates. After empty tube implantation, no regenerated structures were observed in the conduit. However, after implanting tubes filled with sections of predegenerated sciatic nerves or a fibrin-fibronectin-containing matrix provided by peripheral regeneration chambers, numerous regenerated axons were detected 6 weeks after the operation. At the electron microscopic level, regenerated axons were observed in the grafted sciatic nerves in contact with Schwann cells but also in contact with astrocytes which were able to migrate and send processes into the graft. After fibrin-fibronectin-containing-matrix implantation, the regenerated structure between septum and hippocampus was composed mainly of fibroblasts, astrocytes, and regenerated axons associated to these central glial cells.

Axonal regeneration after peripheral nerve grafting and fibrin-fibronectin-containing matrix implantation on the injured septohippocampal pathway of the adult rat: a light and electron microscopic study

The damaged septohippocampal pathway was utilized to study the axonal regeneration of injured neurons. Semipermeable tubes, 2-mm long, were placed in the axis of the transected septohippocampal pathway of adult rats. In a first series of experiments, empty tubes were implanted. Even six weeks after the operation, no regenerated axons were observed in the conduit. In a second series of experiments, in order to validate our approach, segments of pre-degenerated sciatic nerves were introduced into the tubes. Under these experimental conditions, acetylcholinesterase (AChE)-containing regenerated axonal processes were detected in the grafted sciatic nerves. Glial fibrillary acidic protein (GFAP)-immunodetection showed that astroglial cells and astrocyte processes were able to progress on and into the peripheral grafts. At the electron microscopic level, axons were observed in close contact with Schwann cells which myelinated some of them. In some other cases, unmyelinated axons were also present at the surface of reactive astroglial cells filled by numerous intermediate filaments. These central glial cells had migrated among the sciatic nerve collagen fibers. No axon was detected without glial cell contact. In a third series of experiments, we implanted semipermeable tubes previously filled with a fibrin-fibronectin-containing matrix provided by peripheral regeneration chambers. One week after the implantation of the tubes containing this peripheral substrate, different cell types were observed migrating into the conduit and replacing the fibrin-fibronectin-containing matrix. Among these cells astrocytes were present as revealed by GFAP-immunocytochemistry and electron microscopic examinations. During the following weeks, axons were detected in contact with the reactive astroglial cells. AChE-histochemistry showed that axons were able to cross the two millimeter distance separating the septal part and the hippocampal part of the lesion site. GABA (γ-aminobutyric acid)-ergic fibers were also detected in the regenerated structure. These experiments show that cellular or acellular substrates provided by the PNS can promote the regeneration of CNS GABAergic and cholinergic neurons. Our observations suggest that astrocytes can take an important part, after their migration or after extending processes, in the axonal regeneration in the adult CNS of the rat, possibly in furnishing a cellular terrain for the progression of growth cones over a distance of two millimeters and in maintaining regenerated axons at least until the sixth week after the operation.

Axonal growth and glial migration from co-cultured hippocampal and septal slices into fibrin-fibronectin-containing matrix of peripheral regeneration chambers: a light and electron microscope study

In order to investigate whether a fibrin-fibronectin-containing matrix of a peripheral regeneration chamber could promote the growth of central nervous system neurons, hippocampal and septal slices were co-cultured in the presence of this acellular substrate. In introducing the peripheral matrix into a 2-mm-long tube between hippocampal and septal slices, a spatio-temporal sequence of cell migration and axonal growth was described by light and electron microscopy. Axons were able to elongate directly into the flocculent material constituting the matrix and a possible neurite-promoting activity was implicated in this process as axonal growth was not detected in direct contact with rat plasma coagulated with calcium, or chicken plasma coagulated with thrombin, used as control matrices. However, in the 3 different substrates tested, astrocytes were able to migrate and dilated astroglial processes containing intermediate filaments were detected. Axonal processes were observed growing on the glial cell surface. GFAP-positive phagocytic cells, that could be of the same origin as astrocytes, were involved in matrix removing. Neuronal growth and glial migration arose from hippocampal and septum slices and acetylcholinesterase-containing fibers were seen in the bridging structure suggesting that cholinergic axons were able to progress to the hippocampal slice. This technique appeared to provide a model in which axonal growth and cell migration can be studied 'in vitro' in a 3-dimensional environment.

Nuclear textural changes preceding endotoxin mediated enhancement of thromboplastin synthesis in human endothelial cells in vitro

Human vascular endothelium plays a major role in hemostatic processes. Human venous endothelial cells (HEC) may promote coagulation by generation of thromboplastin. This tissue factor production is enhanced by bacterial lipopolysaccharide (LPS). However, the mechanisms of this enhancement remain unclear. In order to quantify by image analysis the nuclear modifications induced by LPS on HEC, umbilical cord vein HEC were cultured in vitro with or without E. coli LPS (10 micrograms/ml) for 0 to 6 h. At the end of culture, tissue factor expression was evaluated by the ability of a cellular extract to shorten the coagulation time of human citrated plasma. Simultaneously, the morphology of LPS treated and control HEC was analysed using a SAMBA 200 cell image processor after Feulgen staining. This analysis indicates that LPS treatment induces nuclear modifications as early as 1 h after culture onset, before any tissue factor expression. This activity appears only between 2 and 4 h of culture with LPS. Our data show that image analysis permits the detection of very early nuclear events in HEC and that these events precede the expression of functional properties which may be implicated in thrombotic processes.

[The importance of software for the planning and adjusting of dosage. Application with aminoglycosides]

We are presenting a Mac Intosh--Apple computer program (Excel*) for the aminoglycosides (AG) drug monitoring useful in the following situations: --initiation of an AG's dosing regimen depending on the desired peak and through concentration (AG's pharmacokinetic parameters have been calculated according to the AG's literature values). --an adequate dosing regimen after revision of the patient's parameters (calculated with the observed concentrations). The technique has been validated comparing desired (des. C) and measured concentrations (mes. C). --either at the beginning of the treatment, --or after revision of the individual parameters. In the first case, the correlation coefficient obtained between 14 des C and 14 mes. C is equal to 0.91 and is improved when individual parameters are calculated (0.94).