Liver Transplantation for Decompensated Cirrhosis Secondary to Telomerase Reverse Transcriptase Mutation

TERT de novo mutation-associated dyskeratosis congenita and porto-sinusoidal vascular disease: a case report

BACKGROUND

Dyskeratosis congenita is a rare genetic disease due to telomere biology disorder and characterized by heterogeneous clinical manifestations and severe complications. "Porto-sinusoidal vascular disease" has been recently proposed, according to new diagnostic criteria, to replace the term "idiopathic non-cirrhotic portal hypertension." TERT plays an important role in telomeric DNA repair and replication. A TERT c.2286 + 1G/A mutation in a splicing consensus site was identified in a patient with pulmonary fibrosis. Recently, a pathogenic de novo TERT c.280A > T variant was associated with diffuse lung disease in an infant.

CASE PRESENTATION

A 16-year-old Han male patient experienced unexplained black stool for 7 days, accompanied by dizziness and fatigue. On examination, there were mesh pigmentations on the exposed areas of the skin on both hands and feet. Laboratory testing revealed moderate hemorrhagic anemia and mild elevation of alanine aminotransferase. A computed tomography scan showed portal hypertension, esophageal and gastric varices, and splenomegaly. The liver stiffness measurement by FibroScan was 6.0 kPa. Liver biopsy revealed typical features of porto-sinusoidal vascular disease. Whole exome sequencing identified a heterozygous TERT c.2286 + 1G > A de novo mutation and quantitative polymerase chain reaction revealed very short telomeres (less than the first percentile for his age). The patient was diagnosed as TERT de novo mutation-related dyskeratosis congenita and porto-sinusoidal vascular disease. He underwent esophageal and gastric variceal ligation treatment and received a carvedilol tablet (12.5 mg) every morning. After 6 months, he has moderate iron deficiency anemia and has started receiving polysaccharide iron complex therapy.

CONCLUSION

When discovering reticular rash and unknown portal hypertension, it is necessary to perform whole exome sequencing and chromosome length testing to clarify the possibility of dyskeratosis congenita/telomere biology disorder with porto-sinusoidal vascular disease.

Simultaneous Liver and Kidney Transplantation in a Patient With Telomere Biology Disorder: A Case Study

Organ transplantation is the primary therapy for organ failure caused by telomere biology disorder (TBD). We describe the first documented case of simultaneous liver and kidney transplantation (SLKTx) for TBD, although the diagnosis of TBD was reached only three months following SLKTx. The patient was born prematurely, displayed growth retardation, and developed chronic kidney and liver diseases. His pre-SLKTx autoimmune, metabolic, and viral assessments were negative, and persistent pancytopenia (bone marrow cellularity 70-80%) was attributed to renal disease-associated bone marrow changes. Following SLKTx, he was discharged with stable graft function on tacrolimus and prednisolone. Although mycophenolate mofetil was discontinued on the second postoperative day, his pancytopenia persisted. Despite extensive evaluations, including drug, immune, nutritional, and viral assessments, all results were negative. A bone marrow biopsy conducted three months post-transplant revealed significant hypocellularity (40-50%). Whole genome sequencing revealed a likely pathogenic variant of the TINF2 gene. The patient was subsequently treated with danazol. At the nine-month follow-up post-SLKTx, he exhibited stable graft function and improved cell counts while maintaining triple-drug immunosuppression. Given the lack of uniform diagnostic criteria for TBD, healthcare providers must be vigilant with patients presenting with multi-organ failure and persistent cytopenias. Effective pre-transplant screening for TBD can lead to timely diagnoses, better management, and improved post-transplant outcomes.

Progression of liver disease and portal hypertension in dyskeratosis congenita and related telomere biology disorders

BACKGROUND AND AIMS

Dyskeratosis congenita (DC) and related telomere biology disorders (TBD) are characterized by very short telomeres and multisystem organ involvement including liver disease. Our study aimed to characterize baseline hepatic abnormalities in patients with DC/TBD and determine risk factors associated with liver disease progression.

APPROACH AND RESULTS

A retrospective review was performed on a cohort of 58 patients (39 males) with DC/TBD who were prospectively evaluated at a single institute from 2002 to 2019. The median age at initial assessment was 18 (1.4-67.6) years, and median follow-up duration was 6 (1.4-8.2) years. Patients with autosomal or X-linked recessive inheritance and those with heterozygous TINF2 DC were significantly younger, predominantly male, and more likely to have DC-associated mucocutaneous triad features and severe bone marrow failure compared with autosomal dominant-non- TINF2 DC/TBD patients. Liver abnormality (defined at baseline assessment by laboratory and/or radiological findings) was present in 72.4% of patients with predominantly cholestatic pattern of liver enzyme elevation. Clinically significant liver disease and portal hypertension developed in 17.2% of patients during the 6-year follow-up; this progression was mainly seen in patients with recessive or TINF2 -associated DC. Significant risk factors associated with progression included the presence of pulmonary or vascular disease.

CONCLUSIONS

Our experience shows a high prevalence of cholestatic pattern of liver abnormality with progression to portal hypertension in patients with DC/TBD. Presence of pulmonary and/or vascular disease in patients with recessive or TINF2 DC was an important predictor of liver disease progression, suggesting the need for increased vigilance and monitoring for complications in these patients.

LTSI Consensus Guidelines: Preoperative Pulmonary Evaluation in Adult Liver Transplant Recipients

The relationship between chronic liver disease and respiratory symptoms and hypoxia is well recognized. Over the last century, three pulmonary complications specific to chronic liver disease (CLD) have been characterized: hepatopulmonary syndrome, portopulmonary hypertension, and hepatic hydrothorax. Apart from that coexisting pulmonary disease like chronic obstructive lung disease and interstitial lung disease also complicate the outcomes after liver transplantation (LT). Assessment for evaluation of underlying pulmonary disorders is essential to improve outcomes in patients with CLD, posted for LT. This consensus guideline of the Liver Transplant Society of India (LTSI) provides a comprehensive review of pulmonary issues in CLD, related and unrelated to underlying liver disease and gives recommendations for pulmonary screening in specific clinical scenarios in adults with chronic liver disease planned for LT. This document also aims to standardize the strategies for preoperative evaluation of these pulmonary issues in this subset of patients. Proposed recommendations were based on selected single case reports, small series, registries, databases, and expert opinion. The paucity of randomized, controlled trials in either of these disorders was noted. Additionally, this review will highlight the lacunae in our current evaluation strategy, challenges faced, and will provide direction to potentially useful futuristic preoperative evaluation strategies.

Early-life liver cirrhosis and variable clinical presentation in telomere disease

AIM

Telomeres are DNA sequences of tandem TTAGGG repeats that protect chromosome ends from degradation and instability. Constitutional loss-of-function telomerase mutations result in rapid telomere shortening, premature senescence and cell death. Liver cirrhosis is rare and has only been reported in adults. We present five family members of Bedouin-Muslim origin, all of which carry the same mutation, and yet demonstrate an extremely variable phenotypical presentation, including liver cirrhosis during early childhood.

METHODS

A multidisciplinary long-term follow-up of two healthy and three affected patients was analysed. The mutation (r.95G>C) was identified in all patients using Sanger sequencing. Telomere length samples were obtained and analysed.

RESULTS

Clinical phenotypes were extremely variable, including age at first symptoms, organ involvement, disease severity and patient prognosis. The most prominent clinical phenotype is liver involvement, including end-stage liver disease early in life, which affects three members of the family. Affected patients had markedly shorter telomeres.

CONCLUSION

We describe an unusual presentation of early liver failure in telomere disease patients. Little, if any, is known about the association between the genotype and phenotype among children with telomere disease and whether the mutation we have described (r.95G>C) is predisposed to early severe hepatic involvement.

Telomere biology disorders

Telomere biology disorders (TBD) are a heterogeneous group of diseases arising from germline mutations affecting genes involved in telomere maintenance. Telomeres are DNA-protein structures at chromosome ends that maintain chromosome stability; their length affects cell replicative potential and senescence. A constellation of bone marrow failure, pulmonary fibrosis, liver cirrhosis and premature greying is suggestive, however incomplete penetrance results in highly variable manifestations, with idiopathic pulmonary fibrosis as the most common presentation. Currently, the true extent of TBD burden is unknown as there is no established diagnostic criteria and the disorder often is unrecognised and underdiagnosed. There is no gold standard for measuring telomere length and not all TBD-related mutations have been identified. There is no specific cure and the only treatment is organ transplantation, which has poor outcomes. This review summarises the current literature and discusses gaps in understanding and areas of need in managing TBD.