Multiple Solid Organ Transplantation in Telomeropathy: Case Series and Literature Review

Telomeropathies in Interstitial Lung Disease and Lung Transplant Recipients

Telomeropathies, or telomere biology disorders (TBDs), are syndromes that can cause a number of medical conditions, including interstitial lung disease (ILD), bone marrow failure, liver fibrosis, and other diseases. They occur due to genetic mutations to the telomerase complex enzymes that result in premature shortening of telomeres, the caps on the ends of cellular DNA that protect chromosome length during cell division, leading to early cell senescence and death. Idiopathic pulmonary fibrosis (IPF) is the most common manifestation of the telomere biology disorders, although it has been described in other interstitial lung diseases as well, such as rheumatoid arthritis-associated ILD and chronic hypersensitivity pneumonitis. Telomere-related mutations can be inherited or can occur sporadically. Identifying these patients and offering genetic counseling is important because telomerapathies have been associated with poorer outcomes including death, lung transplantation, hospitalization, and FVC decline. Additionally, treatment with immunosuppressants has been shown to be associated with worse outcomes. Currently, there is no specific treatment for TBD except to transplant the organ that is failing, although there are a number of promising treatment strategies currently under investigation. Shortened telomere length is routinely discovered in patients undergoing lung transplantation for IPF. Testing to detect early TBD in patients with suggestive signs or symptoms can allow for more comprehensive treatment and multidisciplinary care pre- and post-transplant. Patients with TBD undergoing lung transplantation have been reported to have both pulmonary and extrapulmonary complications at a higher frequency than other lung transplant recipients, such as graft-specific complications, increased infections, and complications related to immunosuppressive therapy.

Pulmonary, Hepatic, and Allogeneic Hematopoietic Stem Cell Transplantation in Patients with Telomere Biology Disorders

PURPOSE OF THE REVIEW

This study aimed to summarize evidence and provide consensus-based guidelines for management of transplantation in patients with telomere biology disorders (TBD). Specifically, this review focuses on clinical management of lung, liver, and bone marrow transplantation in TBD patients.

RECENT FINDINGS

TBD patients have specific unique biological vulnerabilities such as T cell immunodeficiency, susceptibility to infections, hypersensitivity to chemotherapy and radiation, and cytopenias. Furthermore, multiple organ involvement at diagnosis makes clinical management especially challenging due to higher degree of organ damage, and stress-induced telomeric crisis. Sequential and combined organ transplants, development of novel radiation and alkylator-free conditioning regimen, and use of novel drugs for graft-versus-host disease prophylaxis are some of the recent updates in the field. Multidisciplinary management is essential to optimize transplant outcomes in patients with TBD. In this review, we provide consensus-based transplant management guidelines for clinical management of transplant in TBD.

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.

Immune aging: biological mechanisms, clinical symptoms, and management in lung transplant recipients

While chronologic age can be precisely defined, clinical manifestations of advanced age occur in different ways and at different rates across individuals. The observed phenotype of advanced age likely reflects a superposition of several biological aging mechanisms which have gained increasing attention as the world contends with an aging population. Even within the immune system, there are multiple age-associated biological mechanisms at play, including telomere dysfunction, epigenetic dysregulation, immune senescence programs, and mitochondrial dysfunction. These biological mechanisms have associated clinical syndromes, such as telomere dysfunction leading to short telomere syndrome (STS), and optimal patient management may require recognition of biologically based aging syndromes. Within the clinical context of lung transplantation, select immune aging mechanisms are particularly pronounced. Indeed, STS is increasingly recognized as an indication for lung transplantation. At the same time, common aging phenotypes may be evoked by the stress of transplantation because lung allografts face a potent immune response, necessitating higher levels of immune suppression and associated toxicities, relative to other solid organs. Age-associated conditions exacerbated by lung transplant include bone marrow suppression, herpes viral infections, liver cirrhosis, hypogammaglobulinemia, frailty, and cancer risk. This review aims to dissect the molecular mechanisms of immune aging and describe their clinical manifestations in the context of lung transplantation. While these mechanisms are more likely to manifest in the context of lung transplantation, this mechanism-based approach to clinical syndromes of immune aging has broad relevance to geriatric medicine.

Clinical manifestations of telomere biology disorders in adults

Telomere biology disorders (TBDs) are a spectrum of inherited bone marrow failure syndromes caused by impaired telomere function due to pathogenic germline variants in genes involved in telomere maintenance. TBDs can affect many organ systems and are often thought of as diseases of childhood. However, TBDs may present in mid- or even late adulthood with features similar to but not always the same as the childhood-onset TBDs. Adult-onset TBDs are often cryptic with isolated pulmonary, liver, or hematologic disease, or cancer, and may lack the classic disease-defining triad of abnormal skin pigmentation, nail dysplasia, and oral leukoplakia. Diagnostics include detection of very short leukocyte telomeres and germline genetic testing. Notably, adult-onset TBDs may show telomeres in the 1st to 10th percentile for age, and some cases may not have an identifiable genetic cause. TBD genetic etiology includes all modes of inheritance, with autosomal dominant the most frequent in adult-onset disease. Variable symptom onset due to incomplete penetrance, variable expressivity, and genetic anticipation add to the diagnostic challenges. Adult-onset TBDs are likely underrecognized, but their correct identification is of utmost importance, since affected patients are faced with numerous clinical complications, including but not limited to an increased risk of malignancies requiring close surveillance for early detection. Currently lung, liver, or hematopoietic cell transplants are the only curative therapeutic approaches but can be complicated by comorbidities, despite improved medical care. This review highlights the challenges of identifying adult-onset TBDs and addresses currently recommended clinical screening measures and therapy options.

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.

First Successful Liver-Alone Transplantation for TERT (Telomerase Reverse Transcriptase)-Telomeropathy-Related Hepatoportal Sclerosis Cirrhosis

Hepatoportal sclerosis is a rare but well-described condition leading to end-stage liver disease. Telomeropathy is a rare genetic disorder which manifests as premature senescence of cells leading to multisystem disease involving bone marrow, lungs and skin. To the best of our knowledge, there is no report of telomeropathy precipitating end-stage liver disease. Our case presented hepatopulmonary syndrome. Herein, we report a successful liver transplantation in a patient who suffered hepatoportal cirrhosis from telomerase reverse transcriptase (TERT)-telomeropathy.

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.

Disease progression and clinical outcomes in telomere biology disorders

Dyskeratosis congenita related telomere biology disorders (DC/TBDs) are characterized by very short telomeres caused by germline pathogenic variants in telomere biology genes. Clinical presentations can affect all organs, and inheritance patterns include autosomal dominant (AD), autosomal recessive (AR), X-linked (XLR), or de novo. This study examined the associations between mode of inheritance with phenotypes and long-term clinical outcomes. Two hundred thirty-one individuals with DC/TBDs (144 male, 86.6% known genotype, median age at diagnosis 19.4 years [range 0 to 71.6]), enrolled in the National Cancer Institute's Inherited Bone Marrow Failure Syndrome Study, underwent detailed clinical assessments and longitudinal follow-up (median follow-up 5.2 years [range 0 to 36.7]). Patients were grouped by inheritance pattern, considering AD-nonTINF2, AR/XLR, and TINF2 variants separately. Severe bone marrow failure (BMF), severe liver disease, and gastrointestinal telangiectasias were more prevalent in AR/XLR or TINF2 disease, whereas pulmonary fibrosis developed predominantly in adults with AD disease. After adjusting for age at DC/TBD diagnosis, we observed the highest cancer risk in AR/XLR individuals. At last follow-up, 42% of patients were deceased with a median overall survival (OS) of 52.8 years (95% confidence interval [CI] 45.5-57.6), and the hematopoietic cell or solid organ transplant-free median survival was 45.3 years (95% CI 37.4-52.1). Significantly better OS was present in AD vs AR/XLR/TINF2 disease (P < .01), while patients with AR/XLR and TINF2 disease had similar survival probabilities. This long-term study of the clinical manifestations of DC/TBDs creates a foundation for incorporating the mode of inheritance into evidence-based clinical care guidelines and risk stratification in patients with DC/TBDs. This trial was registered at www.clinicaltrials.gov as #NCT00027274.

Liver transplant recipient with respiratory failure due to pulmonary fibrosis related to telomere disease requiring lung transplantation

Short telomere syndrome (STS) is characterized as multiorgan dysfunction presenting with unexplained cytopenias, cryptogenic cirrhosis and pulmonary fibrosis. We present a liver transplant recipient that gradually developed hypoxic respiratory failure attributed to idiopathic pulmonary fibrosis associated telomere disease that culminated in a successful single lung transplantation.

Lung Transplant Improves Survival and Quality of Life Regardless of Telomere Dysfunction

Introduction: Fibrotic interstitial lung diseases (ILDs) are the first indication for lung transplantation (LT). Telomere dysfunction has been associated with poor post-transplant outcomes. The aim of the study was to evaluate the morbi-mortality and quality of life in fibrotic ILDs after lung transplant depending on telomere biology.

Methods: Fibrotic ILD patients that underwent lung transplant were allocated to two arms; with or without telomere dysfunction at diagnosis based on the telomere length and telomerase related gene mutations revealed by whole-exome sequencing. Post-transplant evaluation included: (1) short and long-term mortality and complications and (2) quality of life.

Results: Fifty-five percent of patients that underwent LT carried rare coding mutations in telomerase-related genes. Patients with telomere shortening more frequently needed extracorporeal circulation and presented a higher rate of early post-transplant hematological complications, longer stay in the intensive care unit (ICU), and a higher number of long-term hospital admissions. However, post-transplant 1-year survival was higher than 80% regardless of telomere dysfunction, with improvement in the quality of life and oxygen therapy withdrawal.

Conclusions: Post-transplant morbidity is higher in patients with telomere dysfunction and differs according to elapsed time from transplantation. However, lung transplant improves survival and quality of life and the associated complications are manageable.

Selection Criteria for Lung Transplantation: Controversies and New Developments

Lung transplantation is an accepted therapeutic option for end-stage lung diseases. The imbalance between limited availability and vast need of donor organs necessitates careful selection of recipient candidates, ensuring the best possible utilization of the scarce resource of organs. Nonetheless, possible lung transplant candidates who could experience a meaningful improvement in survival and quality of life should not be excluded solely based on the complexity of their case. In this review, controversial issues or difficult limitations for lung transplantation, and new developments in recipient selection criteria, are discussed, which may help broaden recipient eligibility for lung transplantation without compromising long-term outcomes.

Combined lung and liver transplantation for noncirrhotic portal hypertension with severe hepatopulmonary syndrome in a patient with dyskeratosis congenita

DC is caused by defects at the level of telomere maintenance, and cells from patients with this disease have abnormally short telomeres and show premature senescence. One consequence of DC is bone marrow failure. Thus, patients with DC often require HSCT. However, HSCT does not ameliorate other DC-related manifestations. In fact, HSCT can accelerate organ dysfunction due to treatment-related complications, and solid organ transplantation is required in some patients with DC. In this report, we describe the clinical course of a 5-year-old boy who was transferred to our hospital because of progressive dyspnea, 2 years after HSCT. At admission, he had tachypnea and hypoxemia. A liver biopsy was performed for suspected HPS caused by PH, and LT was considered. Eventually, his hypoxemia worsened, and he was transferred to a PICU and started on VA ECMO. He subsequently underwent a CLLT. ECMO was stopped on post-operative day 12, extubation was achieved on post-operative day 29, and the patient recovered well from the surgery. Our results show that CLLT could be a life-saving treatment option for DC patients with very severe HPS in whom a poor outcome is expected after LT.

An update on the biology and management of dyskeratosis congenita and related telomere biology disorders

Introduction: Telomere biology disorders (TBDs) encompass a group of illnesses caused by germline mutations in genes regulating telomere maintenance, resulting in very short telomeres. Possible TBD manifestations range from complex multisystem disorders with onset in childhood such as dyskeratosis congenita (DC), Hoyeraal-Hreidarsson syndrome, Revesz syndrome and Coats plus to adults presenting with one or two DC-related features.Areas covered: The discovery of multiple genetic causes and inheritance patterns has led to the recognition of a spectrum of clinical features affecting multiple organ systems. Patients with DC and associated TBDs are at high risk of bone marrow failure, cancer, liver and pulmonary disease. Recently, vascular diseases, including pulmonary arteriovenous malformations and gastrointestinal telangiectasias, have been recognized as additional manifestations. Diagnostics include detection of very short leukocyte telomeres and germline genetic testing. Hematopoietic cell transplantation and lung transplantation are the only current therapeutic modalities but are complicated by numerous comorbidities. This review summarizes the pathophysiology underlying TBDs, associated clinical features, management recommendations and therapeutic options.Expert opinion: Understanding TBDs as complex, multisystem disorders with a heterogenous genetic background and diverse phenotypes, highlights the importance of clinical surveillance and the urgent need to develop new therapeutic strategies to improve health outcomes.