FATP4 deletion in liver cells induces elevation of extracellular lipids via metabolic channeling towards triglycerides and lipolysis

Evidence from mice with global deletion of fatty-acid transport protein4 (FATP4) indicates its role on β-oxidation and triglycerides (TG) metabolism. We reported that plasma glycerol and free fatty acids (FA) were increased in liver-specific Fatp4 deficient (L-FATP4-/-) mice under dietary stress. We hypothesized that FATP4 may mediate hepatocellular TG lipolysis. Here, we demonstrated that L-FATP4-/- mice showed an increase in these blood lipids, liver TG, and subcutaneous fat weights. We therefore studied TG metabolism in response to oleate treatment in two experimental models using FATP4-knockout HepG2 (HepKO) cells and L-FATP4-/- hepatocytes. Both FATP4-deificient liver cells showed a significant decrease in β-oxidation products by ∼30-35% concomitant with marked upregulation of CD36, FATP2, and FATP5 as well as lipoprotein microsomal-triglyceride-transfer protein genes. By using 13C3D5-glycerol, HepKO cells displayed an increase in metabolically labelled TG species which were further increased with oleate treatment. This increase was concomitant with a step-wise elevation of TG in cells and supernatants as well as the secretion of cholesterol very low-density and high-density lipoproteins. Upon analyzing TG lipolytic enzymes, both mutant liver cells showed marked upregulated expression of hepatic lipase, while that of hormone-sensitive lipase and adipose-triglyceride lipase was downregulated. Lipolysis measured by extracellular glycerol and free FA was indeed increased in mutant cells, and this event was exacerbated by oleate treatment. Taken together, FATP4 deficiency in liver cells led to a metabolic shift from β-oxidation towards lipolysis-directed TG and lipoprotein secretion, which is in line with an association of FATP4 polymorphisms with blood lipids.

Primary Biliary Cholangitis (PBC)-Autoimmune Hepatitis (AIH) Variant Syndrome: Clinical Features, Response to Therapy and Long-Term Outcome

INTRODUCTION

Standardization of diagnostic criteria of autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) variant syndrome (AIH-PBC VS) has not been achieved so far and evidence-based recommendations for monitoring and treatment of the disease are still lacking. Our study aimed to assess the prevalence, biochemical, and serological features, as well as the clinical course, of VS.

METHODS

We performed a retrospective study including all patients with VS between 1999 and 2020 in four German centers. Data on demographic parameters, biochemical and serological tests, treatment, and outcome were collected.

RESULTS

Of 90 patients (3.1%) meeting Paris criteria for VS diagnosis, 65.6% showed AIH and PBC histological features, while biochemical Paris criteria were observed comparatively rarely. Further antibodies, which were not part of the diagnostic criteria of VS, were found in a subgroup of patients with available data (ACA: 30.0%; anti-CENP-A: 25.0%; anti-CENP-B: 33.3%; anti-SP100: 21.4%). Biochemical response was more frequently observed in patients treated with a combined therapy of ursodeoxycholic acid (UDCA) and immunosuppression (IS). Liver cirrhosis was detected in 31 patients (34.4%) and 25 patients (27.8%) developed clinical manifestations of portal hypertension.

CONCLUSIONS

Biochemical Paris criteria of VS were rarely detected, thus implying that these cut-off values should be redefined. Regarding pharmacological treatment, combined therapy of UDCA and IS appeared to be more effective than monotherapy with UDCA.

Hepatic sarcoidosis: Clinical characteristics and outcome

BACKGROUND & AIMS

Clinical manifestation of hepatic involvement in sarcoidosis can vary from asymptomatic disease to severe complications such as cirrhosis and portal hypertension. However, data on hepatic sarcoidosis are limited, and evidence-based recommendations are lacking. Our study aimed to assess the features and clinical course of hepatic sarcoidosis in a predominantly Caucasian cohort.

METHODS

We performed a retrospective study including all patients with hepatic sarcoidosis between 2004 and 2020 in 5 German centres. The median follow-up time was 36 months (range 0.0-195). Data on demographic parameters, clinical manifestations, diagnostic test results, treatment, and outcome were collected.

RESULTS

A total of 1,476 patients with sarcoidosis and 62 patients with hepatic involvement (4.2%) were identified. Of the patients, 51.6% were female, and 80.6% were Caucasian. Most patients were asymptomatic and were observed to have a cholestatic pattern of liver enzyme elevations. Cirrhosis was detected in 9 patients (14.5%), of whom 6 developed clinical manifestations of portal hypertension. Fifty-four patients were medically treated, most commonly with glucocorticoids (69.4%) or ursodeoxycholic acid (UDCA) (40.3%). Levels of alkaline phosphatase (ALP) decreased by 60.8% on average from baseline in patients treated with glucocorticoids and by 59.9% in patients treated with UDCA. Seventeen patients received treatment augmentation with a second line agent, of whom 8 patients normalised ALP levels during follow-up. None of the patients underwent liver transplantation or developed hepatocellular carcinoma (HCC). Three of the patients died during follow-up owing to liver-related complications.

CONCLUSIONS

Hepatic involvement in sarcoidosis was found in 4.2% of patients with sarcoidosis and was clinically significant in 14.5% of those. These findings highlight the importance of early identifying, monitoring, and treating hepatic sarcoidosis, given its increased mortality when associated with end-stage liver disease.

LAY SUMMARY

Clinical diagnostic and surveillance of hepatic involvement in sarcoidosis has not been standardised, and management of hepatic involvement is a clinical challenge, since it remains poorly characterised in many ways. Our results show that one-third of patients with hepatic sarcoidosis presented with clinically significant portal hypertension, 14.5% suffered from cirrhosis, and 3 patients died owing to liver-related complications. Regarding pharmacological treatment options, corticosteroids and UDCA were the medical agents most frequently used, and both of them have been shown to induce biochemical response in the majority of patients. These findings highlight the importance of correctly and early identifying hepatic involvement in sarcoidosis, because of the potentially progressive course of disease.

Case report: a rare cause of a hypervascular nodule in a noncirrhotic liver

A 37-year-old male patient with Crohn’s disease and multiple liver hemangiomas was referred to our hospital for an atypical hypervascular hepatic lesion detected on an external magnetic resonance imaging (MRI) scan. The patient was otherwise well and had no history of any liver disease. Liver values and tumor markers were normal. Contrast-enhanced ultrasound confirmed multiple hemangiomas in different liver segments and a hypervascular tumor with a hypovascular rim in segment II/IV. Repeat MRI showed a strongly enhancing neoplasm of 2.6 cm with a texture distinctly different from the otherwise relatively uniform hemangiomas, without evidence of interim growth. Ultrasound-guided biopsy revealed a hepatic small vessel neoplasm. Due to the unknown malignant potential, atypical segmental surgical resection was performed. Final histopathological analysis confirmed the complete resection of the lesion. The postoperative course was uneventful.

Wilson disease: Health-related quality of life and risk for depression

BACKGROUND

Wilson disease is an autosomal recessive disorder of copper metabolism and requires lifelong medical treatment. Therefore, the analysis of quality of life has gathered more attention. Aims of this study were to examine risk for depression and health-related quality of life in patients suffering from Wilson disease.

METHODS

Sixty-eight patients were included in this retrospective cross sectional study. The Personal Health Questionnaire-9 Depression Scale was used to assess depression. The Short Form-36 Health Survey questionnaire was used to assess health-related quality of life.

RESULTS

The Personal Health Questionnaire-9 indicated that 21% (14/68) of patients were at risk for major depressive disorders (scores>10) and 35% (24/68) were at risk for mild depression (scores 5-9). Women had significantly lower life quality scores than men. Primary neurologic disease manifestation was associated with significantly lower total Short Form-36 and subdimension scores compared with primary hepatic or mixed presentation. Overall, patients with Wilson disease experienced higher quality of life than patients with other chronic liver diseases.

CONCLUSIONS

As patients with Wilson disease have a high risk for depressive disorders, active assessment for depression is mandatory. Patients with primary neurological symptoms are at higher risk for reduction of life quality.

Concomitant immune-related events in Wilson disease: implications for monitoring chelator therapy

BACKGROUND AND AIMS

Current guidelines favor the use of chelating agents (d-penicillamine, trientine) in first line therapy of symptomatic Wilson disease patients. Development of chelator induced immunological adverse events are a concern especially under d-penicillamine therapy. This study assessed the prevalence of co-existing or therapy-related immune-mediated diseases in Wilson disease patients, and evaluated the role of antinuclear antibodies in therapy monitoring.

METHODS

We retrospectively analyzed 235 Wilson disease patients. Medical regimens were classified and analyzed in relation to adverse events and antinuclear antibody courses.

RESULTS

Coexisting immune-mediated diseases were evident in 19/235 (8.1%) patients, of which 13/235 (5.5%) had pre-existing autoimmune diseases. Six patients (2.6%) developed an autoimmune disease under therapy, all of them under long-term d-penicillamine treatment. Data relating to antinuclear antibody courses during treatment and adverse events were available for patients treated with d-penicillamine (n = 91), trientine (n = 58), and zinc salts (n = 58). No significant increase in antinuclear antibody titers in patients treated with d-penicillamine (16/91; 17.6%), trientine (12/58; 20.7%), and zinc (7/58; 12.1%) were found.

CONCLUSION

Under long-term d-penicillamine therapy a minority of patients developed immune-mediated disease. Elevations in antinuclear antibodies were found frequently, but no correlations were evident between increases in antinuclear antibodies and the development of immune-mediated diseases or medical regimes. Thus, the value of antinuclear antibodies for monitoring adverse events under chelator therapy seems to be limited.

Bone demineralisation in a large cohort of Wilson disease patients

AIMS AND BACKGROUND

We compared the bone mineral density (BMD) of adult Wilson disease (WD) patients (n = 148), with an age- and gender-matched healthy control population (n = 148). Within the WD cohort, correlations of BMD with WD disease parameters, lab results, type of treatment and known osteoporosis risk factors were analysed.

METHODS

Hip and lumbar spine absolute BMD and T-score were measured by dual-energy X-ray absorptiometry. Osteoporosis and osteopenia were defined as a T-score ≤ -2.5, and between -1 and -2.5, respectively.

RESULTS

There were significantly more subjects with abnormal T-scores in the WD population (58.8%) than in the control population (45.3%) (χ(2) = 6.65, df = 2, p = 0.036), as there were 50.0% osteopenic and 8.8% osteoporotic WD patients, vs. 41.2% and 4.1%, respectively, in the controls. Especially L2-L4 spine BMD measurements (BMD and T-scores) differed significantly between the WD population and matched controls. L2-L4 spine BMD for WD patients was on average 0.054 g/cm(2) (5.1%) lower than in matched normal controls (0.995 ± 0.156 vs 1.050 ± 0.135; p = 0.002). We found no significant correlation between BMD values and any of the WD disease parameters (e.g. the severity of liver disease), lab results, type of treatment or known osteoporosis risk factors. Duration of D-penicillamine treatment was negatively correlated with femoral BMD value, but in a clinically irrelevant manner, compared to age and gender. Importantly, BMD remained significantly lower in WD patients (n = 89) vs. controls after excluding WD patients with cirrhosis (p = 0.009).

CONCLUSIONS

Our study suggests that WD is intrinsically associated with bone demineralisation.

Coagulation Parameters in Wilson Disease

Background & Aims: Wilson disease (WD) is an autosomal recessive disorder of copper metabolism. Alterations of copper metabolism have been associated with changes in coagulation factors. The aim of the present study was the analysis of coagulation factors in WD patients.Methods: 100 patients attending a tertiary WD outpatient clinic were analyzed in a prospective cross sectional cohort study. Out of peripheral venous blood samples coagulation factors were assessed including: full blood count, INR, partial thromboplastin time (PTT), clotting factors II, V, VII, VIII, IX, X, XI, XII, XIII, von Willebrand factor/-antigen, fibrinogen, antithrombin III, protein S, protein C, activated protein C (APC) resistance. Subgroup analyses of the blood tests were performed for sex, initial clinical presentation, WD treatment and liver function.Results: Subgroup analysis by liver function showed decreased levels of factors II, V, VII and X. Subgroup analysis by gender or clinical course of the disease did not reveal significant coagulation changes. In patients treated with trientine significantly decreased levels of factors II, VII and antithrombin III and increased von Willebrand factor/-antigen levels were detected. Factor VIII levels were significantly reduced in patients receiving zinc.Conclusion: Although significant differences of some coagulation parameters in subgroup analysis were found, no clinically relevant alterations of the coagulation system in WD patients could be detected.

An unusual case of paralytic ileus

A 26-year-old female patient presented with the clinical picture of an acute ileus. Since childhood the patient has been diagnosed as having a MELAS syndrome, a mitochondriopathy. A subtotal colectomy was performed some years ago because of a similar ileus episode. The further diagnostic work-up revealed an expanded small intestine in abdominal radiography. Laboratory analysis showed increased levels of serum lactate with a consecutive respiratory compensated metabolic acidosis. A conservative treatment regime with nasogastric tube, fluid therapy, parental nutrition via peripheral veins and peristalsis inducing drugs was initiated, but did not resolve ileus symptoms. Under the hypothesis that in MELAS syndrome the ileus-related catabolic state aggravates the ileus symptoms in terms of a circulus vitiosus, we started high-caloric parenteral nutrition by using a central venous catheter. A few hours after this intervention, a clear clinical improvement could be observed. Since this initial presentation, the patient was admitted to our hospital several times with the same ileus symptoms. Each of the episodes was successfully and rapidly treated by this high-caloric parenteral nutrition therapy. The reproducible rapid clinical improvement after starting parenteral nutrition supports the hypothesis that an optimal energy supply is the key therapy not only for cerebral but also for gastrointestinal symptoms in patients with MELAS syndrome.

Iron metabolism and the role of HFE gene polymorphisms in Wilson disease

Wilson disease (WD) is a rare inherited disorder of copper metabolism, which can lead to severe liver failure and to a variety of neuropsychiatric symptoms. Previous animal studies and case reports suggest that hepatic iron overload and alterations in iron processing are associated with WD. The aim of this study was the assessment of iron metabolism and of the frequency of the most common HFE gene polymorphisms in WD patients.

PATIENTS AND METHODS

Data from 143 patients with WD were analysed. Clinical presentation, liver function and iron metabolism parameters were recorded. Blood samples of the patients were analysed for HFE gene alterations (H63D; C282Y). Twenty-seven liver biopsies of these patients were studied with regard to iron content and fibrosis score.

RESULTS

Contrary to previous reports of HFE gene polymorphisms in WD patients, in our cohort the allele frequencies (C282Y: 2.1%; H63D: 7.3%) were in line with frequencies obtained for general population. Male WD patients with decreased serum ceruloplasmin (Cp), showed increased serum ferritin levels. Hepatic iron content was normal in most cases.

DISCUSSION

Male patients with very low Cp serum concentrations showed slightly elevated median serum ferritin concentrations, probably related to lack of ferroxidase acitivity. However, in consideration of absolute numbers of ferritin concentrations, these changes seem to be of minor clinical relevance.

Alterations of lipid metabolism in Wilson disease

INTRODUCTION

Wilson disease (WD) is an inherited disorder of human copper metabolism, characterised by accumulation of copper predominantly in the liver and brain, leading to severe hepatic and neurological disease. Interesting findings in animal models of WD (Atp7b-/- and LEC rats) showed altered lipid metabolism with a decrease in the amount of triglycerides and cholesterol in the serum. However, serum lipid profile has not been investigated in large human WD patient cohorts to date.

PATIENTS AND METHODS

This cohort study involved 251 patients examined at the Heidelberg and Dresden (Germany) University Hospitals. Patients were analysed on routine follow-up examinations for serum lipid profile, including triglycerides, cholesterol, high density lipoprotein (HDL) and low density lipoprotein (LDL). Data on these parameters at time of diagnosis were retrieved by chart review where available. For statistical testing, patients were subgrouped by sex, manifestation (hepatic, neurological, mixed and asymptomatic) and treatment (D-penicillamine, trientine, zinc or combination).

RESULTS

A significant difference in total serum cholesterol was found in patients with hepatic symptoms, which diminished under therapy. No alterations were observed for HDL, LDL and triglycerides.

CONCLUSION

Contradictory to previous reports using WD animal models (Atp7b-/- and LEC rats), the most obvious alteration in our cohort was a lower serum cholesterol level in hepatic-affected patients, which might be related to liver injury. Our data suggested unimpaired cholesterol metabolism in Wilson disease under therapy, independent of the applied medical treatment.