Non-alcoholic fatty liver disease in a sample of individuals with bipolar disorders: results from the FACE-BD cohort

OBJECTIVE

Non-Alcoholic fatty liver disease (NAFLD) is becoming the most common liver disease in Western populations. While obesity and metabolic abnormalities are highly frequent in bipolar disorders (BD), no studies have been performed to estimate the prevalence of NALFD in individuals with BD. The aim of our study is to estimate the prevalence of NAFLD and to identify the potential associated risk factors in a large sample of BD individuals.

METHODS

Between 2009 and 2019, 1969 BD individuals from the FACE-BD cohort were included. Individuals with liver diseases, Hepatitis B or C, and current alcohol use disorders were excluded from the analyses. A blood sample was drawn from participants. Screening of NAFLD was determined using fatty liver index (FLI). Individuals with FLI> 60 were considered as having NAFLD.

RESULTS

The prevalence of NAFDL in this sample was estimated at 28.4%. NAFLD was observed in 40% of men and 21% of women. NAFLD was independently associated with older age, male gender, sleep disturbances, and current use of atypical antipsychotics or anxiolytics. As expected, the prevalence of NALFD was also higher in individuals with overweight and in those with metabolic syndrome.

CONCLUSIONS

This study reinforces the view that individuals with BD are highly vulnerable to metabolic and cardiovascular diseases. The prevalence of NAFLD in individuals with BD was two times higher than the prevalence reported in the general population. The regular screening of the MetS in individuals with BD should be therefore complemented by the additional screening of NAFLD among these vulnerable individuals.

Trajectories of functioning in bipolar disorders: A longitudinal study in the FondaMental Advanced Centers of Expertise in Bipolar Disorders cohort

OBJECTIVE

We aimed at identifying distinct trajectories of functioning and at describing their respective clinical characteristics in a cohort of individuals with bipolar disorders.

METHODS

We included a sample of 2351 individuals with bipolar disorders who have been followed-up to 3 years as part as the FondaMental Advanced Centers of Expertise in Bipolar Disorders cohort. Global functioning was measured using the Functioning Assessment Short Test. We used latent class mixed models to identify distinct longitudinal trajectories of functioning over 3 years. Multivariable logistic regression models were used to identify the baseline factors that were associated with the membership to each trajectory of functioning.

RESULTS

Three distinct trajectories of functioning were identified: (1) a majority of individuals (72%) had a stable trajectory of mild functional impairment, (2) 20% of individuals had a stable trajectory of severe functional impairment and (3) 8% of individuals had a trajectory of moderate functional impairment that improved over time. The membership to a trajectory of stable severe versus stable mild functional impairment was associated with unemployment, a higher number of previous hospitalizations, childhood maltreatment, a higher level of residual depressive symptoms, higher sleep disturbances, a higher body mass index and a higher number of psychotropic medications being prescribed at baseline. The model that included these seven factors led to an area under the curve of 0.85.

CONCLUSION

This study enabled to stratify individuals with bipolar disorders according to three distinct trajectories of functioning. The results regarding the potential determinants of the trajectory of severe functional impairment needs to be replicated in independent samples. Nevertheless, these potential determinants may represent possible therapeutic targets to improve the prognosis of those patients at risk of persistent poor functioning.

Clinical evidence-based cutoff limits for GH stimulation tests in children with a backup of results with reference to mass spectrometry

CONTEXT

Cutoff limits of GH stimulation tests to diagnose GH deficiency (GHD) in children and adolescents are not sufficiently validated by clinical studies due to discrepancies in the performance of GH immunoassays and lack of available study populations.

OBJECTIVE

We aimed to establish new cutoff limits for GH stimulation tests based on clinical evidence and compared these immunoassay-based values with an antibody-independent mass spectrometric method.

DESIGN AND SETTING

In a retrospective study, GH cutoff limits for eight different immunoassays and isotope dilution mass spectrometry (ID-MS) were calculated from hGH peak concentrations of short-statured children with and without GHD.

PATIENTS

We compared the serum GH peak concentrations at GH stimulation test of 52 short-statured children and adolescents, who have normal GH secretion at initial workup and normal growth in the follow-up, with the serum GH peak concentrations of 44 GHD patients in the same age range, in order to optimize the cutoff limit calculation.

RESULTS

Discriminant analysis of re-measured GH led to a new cutoff limit of 7.09 μg/l using the iSYS assay (IDS) and the limits for the other seven hGH assays varied between 4.32 and 7.77 μg/l. For ID-MS, cutoffs of 5.48 μg/l (22k GH) and 7.43 μg/l (total GH) were ascertained.

CONCLUSION

The establishment of method-specific clinical evidence-based GH cutoff limits is of importance to ensure adequate clinical diagnosis and treatment of children and adolescents with GHD. ID-MS may become an important tool for providing both reliable and sustainable SI traceability of GH measurements in the future.

Molecular characteristics of Human Endogenous Retrovirus type-W in schizophrenia and bipolar disorder

Epidemiological and genome-wide association studies of severe psychiatric disorders such as schizophrenia (SZ) and bipolar disorder (BD), suggest complex interactions between multiple genetic elements and environmental factors. The involvement of genetic elements such as Human Endogenous Retroviruses type 'W' family (HERV-W) has consistently been associated with SZ. HERV-W envelope gene (env) is activated by environmental factors and encodes a protein displaying inflammation and neurotoxicity. The present study addressed the molecular characteristics of HERV-W env in SZ and BD. Hundred and thirty-six patients, 91 with BD, 45 with SZ and 73 healthy controls (HC) were included. HERV-W env transcription was found to be elevated in BD (P<10-4) and in SZ (P=0.012) as compared with HC, but with higher values in BD than in SZ group (P<0.01). The corresponding DNA copy number was paradoxically lower in the genome of patients with BD (P=0.0016) or SZ (P<0.0003) than in HC. Differences in nucleotide sequence of HERV-W env were found between patients with SZ and BD as compared with HC, as well as between SZ and BD. The molecular characteristics of HERV-W env also differ from what was observed in Multiple Sclerosis (MS) and may represent distinct features of the genome of patients with BD and SZ. The seroprevalence for Toxoplasma gondii yielded low but significant association with HERV-W transcriptional level in a subgroup of BD and SZ, suggesting a potential role in particular patients. A global hypothesis of mechanisms inducing such major psychoses is discussed, placing HERV-W at the crossroads between environmental, genetic and immunological factors. Thus, particular infections would act as activators of HERV-W elements in earliest life, resulting in the production of an HERV-W envelope protein, which then stimulates pro-inflammatory and neurotoxic cascades. This hypothesis needs to be further explored as it may yield major changes in our understanding and treatment of severe psychotic disorders.

Role of keratinocyte growth factor in the control of surfactant synthesis by fetal lung mesenchyme

Fetal lung maturation is regulated by mesenchymal-epithelial cell communication, which plays a major role in the control of surfactant synthesis by alveolar type II cells. We have recently shown that keratinocyte growth factor (KGF), also called fibroblast growth factor-7, enhances the maturation of fetal alveolar epithelial type II cells. Here, we investigated, among the factors produced by lung mesenchyme, the part attributable to KGF in the control of surfactant synthesis. Using a KGF-neutralizing antibody, we assessed surfactant phospholipid synthesis by measuring choline incorporation into disaturated phosphatidylcholine of isolated fetal type II cells. We found that KGF accounts for about half of the stimulating activity present in fetal lung fibroblast-conditioned medium (FCM). By contrast, the use of an epidermal growth factor-neutralizing antibody did not alter the FCM-stimulating activity. To further delineate KGF properties as a mesenchymal mediator, we wondered about its possibility to relay glucocorticoid-stimulating activity on the synthesis of the phospholipid moiety of surfactant in fetal lung fibroblasts. A 24-h exposure to dexamethasone led us to detect a 50% increase in the level of KGF messenger RNA (mRNA) in isolated fetal lung fibroblasts. Moreover, anti-KGF antibody totally abolished the further increase of FCM-stimulating activity induced by dexamethasone. Thus, KGF seems to be a major player in mediating glucocorticoid stimulation of fetal lung maturation.

Application of the combination of isotope ratio monitoring with isotope dilution mass spectrometry to the determination of glucose in serum

Isotope ratio monitoring combined with n((13)C)/n((12)C) isotope dilution mass spectrometry (IRM/IDMS) provides results of low uncertainty of the order of 0.1% if it is applied to the analysis of simple mixtures as found in organic chemistry, even if only low (13)C spike additives to the sample are used. If the method is applied to the analysis of systems that require large-scale sample preparation prior to the measurement, such as the determination of glucose in serum, the results obtained exhibit a higher uncertainty that is comparable to that of the conventional gas chromatography/isotope dilution mass spectrometry (GC/IDMS) method. The reason for this observation is that the small contribution that the IRM/IDMS method makes to the uncertainty budget of the result is superimposed on a large contribution due to the sample preparation. It appears therefore that the IRM/IDMS method has no advantage over the conventional GC/IDMS method. However, if a series of measurements is carried out, and if a suitable experimental design is chosen, the IRM/IDMS method can provide valuable additional information. The influence of sample preparation on each individual result can be quantified as its deviation from the average value of all results of the series. From these data conclusions can be drawn for an improvement in sample preparation.

Memory effects in combining isotope ratio monitoring with isotope dilution mass spectrometry

Combining isotope ratio monitoring with isotope dilution techniques provides very accurate results in the quantitative analysis of volatile organic chemical compounds by gas chromatography/mass spectrometry (GC/MS). However, this method requires that spikes highly enriched in (13)C be used. This may lead to memory effects which will be investigated in more detail. They occur when the component of the mixture to be investigated exhibits an isotope ratio which is different from that of the component eluted earlier from the column during the chromatographic separation process. A residue of this component, which is shown in the gas chromatogram as tailing, falsifies the result of the isotope ratio measurement. This also leads to false amount-of-substance measurement results. Memory effects can be avoided by using spikes of low (13)C content, by adjusting the composition of the reference solution to that of the sample, or by ensuring effective sample preparation, thus separating disturbing mixture components prior to the measurement. Copyright 1999 John Wiley & Sons, Ltd.

Immunochemical characterization and transacting properties of upstream stimulatory factor isoforms

The ubiquitous upstream stimulatory factor (USF) transcription factors encoded by two distinct genes (USF1 and USF2) exist under the form of various dimers able to bind E-boxes. We report the molecular cloning and functional characterization of USF2 isoforms, corresponding to a 44-kDa subunit, USF2a, and a new 38-kDa subunit, USF2b, generated by differential splicing. Using specific anti-USF antibodies, we define the different binding complexes in various nuclear extracts. In vivo, the USF1/USF2a heterodimer represents over 66% of the USF binding activity whereas the USF1 and USF2a homodimers represent less than 10%, which strongly suggests an in vivo preferential association in heterodimers. In particular, an USF1/USF2b heterodimer accounted for almost 15% of the USF species in some cells. The preferential heterodimerization of USF subunits was reproduced ex vivo, while the in vitro association of cotranslated subunits, or recombinant USF proteins, appeared to be random. In transiently transfected HeLa or hepatoma cells, USF2a and USF1 homodimers transactivated a minimal promoter with similar efficiency, whereas USF2b, which lacks an internal 67-amino acid domain, was a poor transactivator. Additionally, USF2b was an efficient as USF1 and USF2a homodimers in transactivating the liver-specific pyruvate kinase gene promoter.

Bcl-2 protects from lethal hepatic apoptosis induced by an anti-Fas antibody in mice

Fas is an apoptosis-signalling cell surface antigen that has been shown to trigger cell death upon specific ligand or antibody binding. Treatment of mice with an anti-Fas antibody causes fulminant hepatic failure due to massive apoptosis. To test a putative protective effect of the anti-apoptotic Bcl-2 protein, transgenic mice were generated to express the human bcl-2 gene product in hepatocytes. Early onset of massive hepatic apoptosis leading to death was observed in all nontransgenic mice treated with an anti-Fas antibody. By contrast, hepatic apoptosis was delayed and dramatically reduced in transgenic animals, yielding a 93% survival rate. These results demonstrate that Bcl-2 is able to protect from in vivo Fas-mediated cytotoxicity, and could be of significance for preventing fulminant hepatic failure due to viral hepatitis in humans.