Liver stiffness increases acutely during sickle cell vaso-occlusive crisis

Long-Term L-Glutamine Treatment Reduces Hemolysis without Ameliorating Hepatic Vaso-Occlusion and Liver Fibrosis in a Mouse Model of Sickle Cell Disease

Sickle cell disease (SCD) is an autosomal recessive monogenic disorder caused by a homozygous mutation in the β-globin gene, which leads to erythrocyte sickling, hemolysis, vaso-occlusion, and sterile inflammation. The administration of oral L-glutamine has been shown to reduce the frequency of pain in SCD patients; however, the long-term effect of L-glutamine in SCD remains to be determined. To understand the long-term effect of L-glutamine administration in the liver we used quantitative liver intravital microscopy and biochemical analysis in humanized SCD mice. We here show that chronic L-glutamine administration reduces hepatic hemoglobin-heme-iron levels but fails to ameliorate ischemic liver injury. Remarkably, we found that this failure in the resolution of hepatobiliary injury and persistent liver fibrosis is associated with the reduced expression of hepatic Kupffer cells post-L-glutamine treatment. These findings establish the importance of investigating the long-term effects of L-glutamine therapy on liver pathophysiology in SCD patients.

Assessment of Liver Fibrosis by Transient Elastography in Children and Young Adults With Sickle Cell Disease With and Without Iron Overload

Transfusion-associated iron overload may cause liver fibrosis. We compared transient elastography (TE) and aspartate aminotransferase-platelet ratio index (APRI), noninvasive markers for hepatic fibrosis, to liver histology in children and young adults with sickle cell disease (SCD) who were iron overloaded (cohort 1). Age-matched subjects with SCD but without iron overload (cohort 2) were enrolled for APRI and TE assessments. Nineteen subjects ages 10 to 21 years were transfused for a mean of 9.67 years, had a mean serum ferritin of 4899±2849 ng/mL, and a liver iron concentration of 15.56±10.12 mg/g dry liver weight by R2-magnetic resonance imaging. Mean APRI was 0.33±0.13 in cohort 1 and 0.27±0.10 in cohort 2. The mean liver stiffness measures (LSM) in cohort 1, assessed by TE, was 8.46±3.95 kPa, ranging from 3.5 to 14.6 kPa (expected normal <7 kPa). Cohort 2 had a mean LSM of 5.72±1.74 kPa (4.6 to 8.7 kPa). There was a good correlation between LSM and histologic fibrosis (t value 6.94, P<0.0001). There was no significant correlation between APRI and histologic fibrosis and between APRI and LSM. A high LSM suggests liver fibrosis in children and adults with SCD with iron overload and may merit histologic confirmation especially if persistent.

Liver damage and sickle cell disease: genotype relationship

Sickle hepatopathy is a severe and not rare complication of sickle cell disease (SCD), showing mainly a cholestatic pattern. So far, no effective approaches to prevent or treat this condition have been recognized. We conducted a single-center observational study in 68 adult sickle cell patients, encompassing 17 with sickle cell anemia (SCA), 38 with sickle cell thalassemia (HbS/β-Thal), and 13 with HbSC disease. The aim of our study was to assess liver damage in the three main forms of SCD, through the evaluation of clinical, laboratory, and imaging findings. In our population, the role of hepatotropic viruses, high BMI, and alcohol consumption in liver damage was ruled out. SCA and HbS/β-Thal patients with lower Hb (p < 0.001), higher HbS (p < 0.001), and frequent vaso-occlusive crises showed functional (GGT values: SCA and HbS/β-Thal vs HbSC p = 0.047 and p = 0.009, respectively) and structural liver abnormalities, defined by abdominal ultrasound and vibration-controlled transient elastography (liver stiffness values: SCA and HbS/β-Thal vs HbSC p 0.022 and p 0.19, respectively), more severe than HbSC patients. Through univariate and multivariate analyses, male sex, SCA genotype, lower HbF, frequent transfusions, increased GGT values, and abnormal liver ultrasound and stiffness were identified as potentially early markers of sickle hepatopathy.

The vaso-occlusive pain crisis in sickle cell disease: Definition, pathophysiology, and management

Early diagnosis, treatment, and prevention of a vaso-occlusive crisis (VOC) are critical to the management of patients with sickle cell disease. It is essential to differentiate between VOC-associated pain and chronic pain, hyperalgesia, neuropathy, and neuropathic pain. The pathophysiology of VOCs includes polymerization of abnormal sickle hemoglobin, inflammation, and adhesion. Hydroxyurea, L-glutamine, crizanlizumab, and voxelotor have been approved by the US Food and Drug Administration for reducing the frequency of VOCs; the European Medicines Agency has approved only hydroxyurea. Other novel treatments are in late-stage clinical development in both the United States and the European Union. The development of agents for prevention and treatment of VOCs should be driven by our understanding of its pathophysiology.

Vibration Controlled Transient Elastography (Fibroscan®) in sickle cell liver disease - could we strike while the liver is hard?

Vibration controlled transient elastography (VCTE) is validated for the evaluation of hepatic fibrosis in different liver diseases. Sickle cell liver disease (SCLD) results from a cumulative hepatic injury and its lifelong and progressive nature raises the need for a non-invasive tool for fibrosis evaluation. Fifty patients, aged between 23 and 59 years with sickle cell disease and suspected SCLD underwent a VCTE followed by a liver biopsy. Biopsies were evaluated for various scores of liver disease that were then correlated to VCTE score. 90% of our patients had an Ishak Fibrosis (IF) score between 0-2 (Group A-minimal to no fibrosis) and 10% of the patients had IF score between 3-6 (Group B-advanced fibrosis). The median Transient Elastography (TE) for patients in Groups A and B was 4·8 kilopascals (kPa) and 17·6 kPa, respectively. A positive correlation was shown between TE and IF score, R = 0·0·68 (P = <0·0001); a positive correlation was also shown with Histology Activity Index fibrosis score, R = 0·64 (P = <0·0001). This study emphasises the need for further studies of non-invasive tools and their utility in liver fibrosis evaluation of patients with SCLD.

Transient Elastography (TE) is a Useful Tool for Assessing the Response of Liver Iron Chelation in Sickle Cell Disease Patients

Sickle cell disease patients often need regular blood transfusions to improve both the quality of life and survival from the veno-occlusive complications of the disease. Deferasirox, a convenient long acting oral agent, has recently been introduced in clinical practice with promising efficacy.

This study aims to evaluate the association of liver stiffness and possible fibrosis with iron deposition and confirm the use of elastography as a validated test of responding to chelation with low cost and easy access.

15 patients with sickle cell disease and systemic or occasional transfusions were evaluated with MRI, transient elastography and biochemistry, for liver iron(LIC) and liver stiffness(LSM) before onset and one year after taking Deferasirox. All patients completed the study.

Our results showed improvement in hepatic iron and hepatic stiffness after chelation therapy; Furthermore ALT, AST, LDH and ferritin levels have improved after 12 months of therapy with deferasirox. During the study no serious adverse events were encountered indicating the safety of the drug.

Transient liver elastography findings correlate with serum ferritin and LIC in patients with sickle cell disease and it is a useful tool for assessing the response of liver iron chelation therapy.

Establishing ultrasound based transient elastography cutoffs for different stages of hepatic fibrosis and cirrhosis in Egyptian chronic hepatitis C patients

BACKGROUND AND STUDY AIM

Transient elastography is widely used to assess fibrosis stage in chronic hepatitis C (CHC). We aimed to establish and validate different transient elastography cut-off values for significant fibrosis and cirrhosis in CHC genotype 4 patients.

PATIENTS AND METHODS

The data of 100 treatment-naive CHC patients (training set) and 652 patients (validation set) were analysed. The patients were subjected to routine pretreatment laboratory investigations, liver biopsy and histopathological staging of hepatic fibrosis according to the METAVIR scoring system. Transient elastography was performed before and in the same week as liver biopsy using FibroScan (Echosens, Paris, France). Transient elastography results were correlated to different stages of hepatic fibrosis in both the training and validation sets.

RESULTS

ROC curves were constructed. In the training set, the best transient elastography cut-off values for significant hepatic fibrosis (≥F2 METAVIR), advanced hepatic fibrosis (≥F3 METAVIR) and cirrhosis (F4 METAVIR) were 7.1, 9 and 12.2 kPa, with sensitivities of 87%, 87.5% and 90.9% and specificities of 100%, 99.9% and 99.9%, respectively. The application of these cut-offs in the validation set showed sensitivities of 85.5%, 82.8% and 92% and specificities of 86%, 89.4% and 99.01% for significant hepatic fibrosis, advanced hepatic fibrosis and cirrhosis, respectively.

CONCLUSION

Transient elastography performs well for significant hepatic fibrosis, advanced hepatic fibrosis and cirrhosis, with validated cut-offs of 7.1, 9 and 12.2 kPa, respectively, in genotype 4 CHC patients.

Impact of genetic polymorphisms in key enzymes of homocysteine metabolism on the pathophysiology of sickle cell anemia

This work aimed at studying a possible influence of methylenetetrahydrofolate reductase (MTHFR; c. 677C>T) and cystathionine β-synthase (CBS; 844ins68) polymorphisms on overall oxidative status of sickle cell anemia (SCA) patients and on routine markers, correlating them with hydroxycarbamide (HC) treatment. We evaluated 95 unrelated and diagnosed SCA patients. All patients received a prophylactic treatment with folic acid of 5mg/day, while 41 (43.2%) of them were under hydroxycarbamide (HC) treatment (average dose: 22mg/kg/day). MTHFR and CBS polymorphisms were identified by Polymerase Chain Reaction. Biochemical parameters were measured using spectrophotometric and chromatographic methods. Routine markers were developed by specialized laboratory. We did not find any effect of 677T and "I" allele combination on the biomarkers evaluated. On the other hand, MTHFR 677T mutation was related to a depletion of antioxidant capacity, according to the decreased catalase activity and a reduction about 30% of glutathione levels. Moreover, the presence of the insertion was related to about 23% less biomolecule oxidation levels and lower monocytes count, but about 14% higher lactate dehydrogenase activity. These findings may contribute to highlight that the MTHFR and CBS polymorphisms involvement in SCA pathophysiology is likely to be far more complex than it was explored to date.

Interim assessment of liver damage in patients with sickle cell disease using new non-invasive techniques

We explored transient elastography (TE) and enhanced liver fibrosis (ELF^™ ) score with standard markers of liver function to assess liver damage in 193 well patients with sickle cell disease (SCD). Patients with HbSS or HbSβ⁰ thalassaemia (sickle cell anaemia, SCA; N = 134), had significantly higher TE results and ELF scores than those with HbSC (N = 49) disease (TE, 6·8 vs. 5·3, P < 0·0001 and ELF, 9·2 vs. 8·6 P < 0·0001). In SCA patients, TE and ELF correlated significantly with age and all serum liver function tests (LFTs). Additionally, (weak) positive correlation was found with lactate dehydrogenase (TE: r = 0·24, P = 0·004; ELF: r = 0·26 P = 0·002), and (weak) negative correlation with haemoglobin (TE: r = -0·25, P = 0·002; ELF: r = -0·25 P = 0·004). In HbSC patients, correlations were weaker or not significant between TE or ELF, and serum LFTs. All markers of iron loading correlated with TE values when corrected for sickle genotype (serum ferritin, β = 0·25, P < 0·0001, total blood transfusion units, β = 0·25, P < 0·0001 and LIC β = 0·32, P = 0·046). The exploratory study suggests that, while TE could have a role, the utility of ELF score in monitoring liver damage in SCD, needs further longitudinal studies.

CT abdominal imaging findings in patients with sickle cell disease: acute vaso-occlusive crisis, complications, and chronic sequelae

Sickle cell disease (SCD) is the most prevalent hemoglobinopathy. Survival in patients with SCD has improved over the past few decades. These patients experience a lifetime of repeated acute pain crises, which are thought to result from sickling and microvascular occlusions; acute abdominal pain is common. Moreover, repeated crises often lead to organ dysfunction, such as asplenia, hepatic failure, and renal failure. The spleen, liver, biliary system, kidneys, and gastrointestinal tract can all be affected. Patients may undergo CT to further direct clinical management. We review the spectrum of CT imaging findings of abdominal manifestations in patients with SCD, from the acute microvascular occlusive pain crisis to the potential complications and chronic sequelae.

Management of Liver Complications in Haemoglobinopathies

Liver complications in haemoglobinopathies (thalassaemia and sickle cell disease) are due to several factors, dominated (beside chronic viral infections, not considered here) by chronic iron overload, biliary obstruction and venous thrombosis. Whereas the latter two factors can cause acute hepatic syndromes, all three mechanisms - when becoming chronic- can produce fibrosis and cirrhosis and even, in thalassaemia, hepatocellular carcinoma. These chronic hepatic complications are an indirect consequence of the significant improvement in life expectancy due to the overall amelioration of disease management. The diagnostic approach has benefited from non invasive (biochemical and imaging) approaches which have considerably reduced the indication of liver biopsy. The therapeutic management involves relatively efficient curative medical, endoscopic or surgical methods, but should rest primarily on preventive measures focused on the haematological causative factors but also on hepatic co-morbidities. This chapter will focus on hepatic complications in thalassaemia and sickle cell disease (SCD), without considering the complications related to virus B or C infections which will be described in another chapter.