Creating an effective clinical registry for rare diseases

Novel α-1,3-Glucosyltransferase Variants and Their Broad Clinical Polycystic Liver Disease Spectrum

Protein-truncating variants in α-1,3-glucosyltransferase (ALG8) are a risk factor for a mild cystic kidney disease phenotype. The association between these variants and liver cysts is limited. We aim to identify pathogenic ALG8 variants in our cohort of autosomal dominant polycystic liver disease (ADPLD) individuals. In order to fine-map the phenotypical spectrum of pathogenic ALG8 variant carriers, we performed targeted ALG8 screening in 478 ADPLD singletons, and exome sequencing in 48 singletons and 4 patients from two large ADPLD families. Eight novel and one previously reported pathogenic variant in ALG8 were discovered in sixteen patients. The ALG8 clinical phenotype ranges from mild to severe polycystic liver disease, and from innumerable small to multiple large hepatic cysts. The presence of <5 renal cysts that do not affect renal function is common in this population. Three-dimensional homology modeling demonstrated that six variants cause a truncated ALG8 protein with abnormal functioning, and one variant is predicted to destabilize ALG8. For the seventh variant, immunostaining of the liver tissue showed a complete loss of ALG8 in the cystic cells. ALG8-associated ADPLD has a broad clinical spectrum, including the possibility of developing a small number of renal cysts. This broadens the ADPLD genotype-phenotype spectrum and narrows the gap between liver-specific ADPLD and kidney-specific ADPKD.

Feasibility Study and Design of Registration System for Upper Gastrointestinal Bleeding Patients in Isfahan Province

Background

Disease registration is an organized system for collecting, storing, retrieving, analyzing a particular disease or exposure to known substances in a specific population. The aim of this study was to assess the feasibility and design of the registration system for upper gastrointestinal bleeding patients based on patients referring to Al-Zahra and Khorshid hospitals, Isfahan, Iran.

Materials and Methods

This study is a research action study in which the members of the registration system team are hospital triage physicians, internal residents in the Emergency department of hospital, subspecialty assistants and gastroenterologists, statisticians (epidemiologists and methodologists), and two trained persons were specified to collect medical information and documents. The data collection tool is a researcher-made checklist. Based on the available tools, the most important criteria related to gastrointestinal bleeding were selected. In the next step, the criteria selected in the council, including team members, were reviewed and a preliminary draft was prepared to record the information of patients.

Results

The results indicated the final version of the checklist in three parts including demographic variables (age, sex, education, et al.), main variables (as the minimum data required by a person to register in the checklist (patient's clinical signs)), extended main variables (its information is designed to be used to diagnose, treat, and follow-up the patient in later stages).

Conclusion

It seems to be predictable by establishing a system for recording gastrointestinal bleeding diseases, disease prevalence, monitoring services and treatment of patients, survival analysis and evaluation of clinical care outcomes, finding patients at higher risk for emergency treatment, reviewing drug interventions, and interventional activities.

Expanding the clinical application of the polycystic liver disease questionnaire: determination of a clinical threshold to select patients for therapy

BACKGROUND

Polycystic liver disease (PLD) causes symptoms resulting from cystic volume expansion. The PLD-specific questionnaire (PLD-Q) captures symptom burden. This study aims to develop a threshold to identify patients with symptoms requiring further exploration and possibly intervention.

METHODS

We recruited PLD patients with completed PLD-Qs during their patient journey. We evaluated baseline PLD-Q scores in (un)treated PLD patients to determine a threshold of clinical importance. We assessed our threshold's discriminative ability with receiver operator characteristic statistics, Youden Index, sensitivity, specificity, positive and negative predictive value parameters.

RESULTS

We included 198 patients with a balanced proportion of treated (n=100) and untreated patients (n=98, PLD-Q scores 49 vs 19, p<0.001; median total liver volume 5827 vs 2185 ml, p<0.001). We established the PLD-Q threshold at 32 points. A score of ≥32 differentiates treated from untreated patients with an area under the ROC of 0.856, Youden Index 0.564, sensitivity of 85.0%, specificity of 71.4%, positive predictive value of 75.2%, and negative predictive value of 82.4%. Similar metrics were observed in predefined subgroups and an external cohort.

CONCLUSION

We established the PLD-Q threshold at 32 points with high discriminative ability to identify symptomatic patients. Patients with a score ≥32 should be eligible for treatment or inclusion in trials.

A Global Overview of Acute Coronary Syndrome Registries: A Systematic Review

The present study was conducted with the aim of identifying, and summarizing the characteristics of ACS registries at national, multinational and international levels. Literature was searched using keywords in the title and/or abstract without any time limit ending in March, 2021. After excluding duplicates, 2 reviewers independently reviewed the titles and/or abstracts and full text for inclusion. Each reviewer independently extracted the characteristics of the registries from included papers. Finally, the extracted characteristics were confirmed by a second reviewer. Out of the 1309 papers included, 71 ACS registries were identified (including 60 national and 11 multinational and international registries). Most national registries were being used in Europe. Most registries focused on measuring quality. In more than half of the registries, all types of ACS patients were enrolled. The diagnostic and drug classification systems were mentioned in eight and five registries, respectively. The design of 55 registries was hospital-based. The ability of computerized audit checks was made for 34 registries. More than half of the registries had patient consent and had a web-based design. In all the ACS registries, patient characteristics, clinical characteristics and treatment characteristics were recorded and post-discharge follow-up information was recorded in 45 registries. In the current situation and given that a limited number of countries in the world have national ACS registries, reviewing the results of this study and modeling the registries implemented in the leading countries can help countries without a registry to design it.

Developing the minimum data set of the corrosive ingestion registry system in Iran

Background

Corrosive ingestion is still a major health problem, and its outcomes are often unpredicted. The implementation of a registry system for poisoning with corrosive substances may improve the quality of patient care and might be useful to manage this type of poisoning and its complications. Therefore, our study aimed to establish a minimum data set (MDS) for corrosive ingestion.

Methods

This was an applied study performed in 2022. First, a literature review was conducted to identify the potential data items to be included in the corrosive ingestion MDS. Then, a two-round Delphi survey was performed to attain an agreement among experts regarding the MDS content, and an additional Delphi step was used for confirming the final MDS by calculating the individual item content validity index (CVI) and content validity ratio (CVR) and by using other statistical tests.

Results

After the literature review, 285 data items were collected and sent to a two-round Delphi survey in the form of a questionnaire. In total, 75 experts participated in the Delphi stage, CVI, kappa, and CVR calculation. Finally, the MDS of the corrosive ingestion registry system was identified in two administrative and clinical sections with 21 and 152 data items, respectively.

Conclusions

The development of an MDS, as the first and most important step towards developing the corrosive ingestion registry, can become a standard basis for data collection, reporting, and analysis of corrosive ingestion. We hope this MDS will facilitate epidemiological surveys and assist policymakers by providing higher quality data capture to guide clinical practice and improve patient-centered outcomes.

Defining and characterising a toolkit for the development of a successful European registry for rare liver diseases: a model for building a rare disease registry

INTRODUCTION

A rare disease is defined by the European Health Commission as a disorder affecting less than 5/10,000 of the population. There are at least 20 rare liver diseases (RLDs) seen frequently in the adult and paediatric liver clinic, signifying that the hepatology community can be influential in developing such patient databases for registering patients with rare hepatic conditions. The aim of this review was, first, to identify registries for RLDs in Europe, and, second, to design a universal blueprint for the development of a registry for RLD by using lessons learnt from the European registries that have already been established.

METHODS

We searched PubMed, Google Scholar and clinicaltrials.gov using the MESH terms 'registries', 'database management systems', 'database' and the non-MESH terms 'database$', 'registry', 'repository' and 'repositories'. We only included studies in English from countries/consortia of the European Union (EU). Our literature search was performed in 2020.

RESULTS

We identified 37 registries for RLDs in Europe. Using information from the design of these registries we designed a blueprint for the development of a patient registry for an RLD consisting of a theoretical, technical and maintenance phase.

DISCUSSION

It is believed that rare diseases may affect as much as 6-8% of the EU population across its 28 member states. Here we have provided a toolkit for designing a registry for an RLD. Our article will complement the efforts of loco-regional, national and international groups seeking to establish robust systems for data collection and analysis for orphan liver diseases.

Imaging of fibropolycystic liver disease

Fibropolycystic liver diseases (FLDs) make up a rare spectrum of heritable hepatobiliary diseases resulting from congenital ductal plate malformations (DPMs) due to the dysfunction of proteins expressed on the primary cilia of cholangiocytes. The embryonic development of the ductal plate is key to understanding this spectrum of diseases. In particular, DPMs can result in various degrees of intrahepatic duct involvement and a wide spectrum of cholangiopathies, including congenital hepatic fibrosis, Caroli disease, polycystic liver disease, and Von Meyenberg complexes. The most common clinical manifestations of FLDs are portal hypertension, cholestasis, cholangitis, and (in rare cases) cholangiocarcinoma. This article reviews recent updates in the pathophysiology, imaging, and clinical management of FLDs.

Abdominal wall hernia is a frequent complication of polycystic liver disease and associated with hepatomegaly

BACKGROUND AND AIM

Polycystic liver disease (PLD) is related to hepatomegaly which causes an increased mechanical pressure on the abdominal wall. This may lead to abdominal wall herniation (AWH). We set out to establish the prevalence of AWH in PLD and explore risk factors.

METHODS

In this cross-sectional cohort study, we assessed the presence of AWHs from PLD patients with at least 1 abdominal computed tomography or magnetic resonance imaging scan. AWH presence on imaging was independently evaluated by two researchers. Data on potential risk factors were extracted from clinical files.

RESULTS

We included 484 patients of which 40.1% (n = 194) had an AWH. We found a clear predominance of umbilical hernias (25.8%, n = 125) while multiple hernias were present in 6.2% (n = 30). Using multivariate analysis, male sex (odds ratio [OR] 2.727 p < .001), abdominal surgery (OR 2.575, p < .001) and disease severity according to the Gigot classification (Type 3 OR 2.853, p < .001) were identified as risk factors. Height-adjusted total liver volume was an independent PLD-specific risk factor in the subgroup of patients with known total liver volume (OR 1.363, p = .001). Patients with multiple hernias were older (62.1 vs. 55.1, p = .001) and more frequently male (22.0% vs. 50.0%, p = .001).

CONCLUSION

AWHs occur frequently in PLD with a predominance of umbilical hernias. Hepatomegaly is a clear disease-specific risk factor.

Protocol for a randomized controlled multicenter trial assessing the efficacy of leuprorelin for severe polycystic liver disease: the AGAINST-PLD study

Background

In patients with severe polycystic liver disease (PLD), there is a need for new treatments. Estrogens and possibly other female sex hormones stimulate growth in PLD. In some patients, liver volume decreases after menopause. Female sex hormones could therefore be a target for therapy. The AGAINST-PLD study will examine the efficacy of the GnRH agonist leuprorelin, which blocks the production of estrogen and other sex hormones, to reduce liver growth in PLD.

Methods

The AGAINST-PLD study is an investigator-driven, multicenter, randomized controlled trial. Institutional review board (IRB) approval was received at the University Medical Center of Groningen and will be collected in other sites before opening these sites. Thirty-six female, pre-menopausal patients, with a very large liver volume for age (upper 10% of the PLD population) and ongoing liver growth despite current treatment options will be randomized to direct start of leuprorelin or to 18 months standard of care and delayed start of leuprorelin. Leuprorelin is given as 3.75 mg subcutaneously (s.c.) monthly for the first 3 months followed by 3-monthly depots of 11.25 mg s.c. The trial duration is 36 months. MRI scans to measure liver volume will be performed at screening, 6 months, 18 months, 24 months and 36 months. In addition, blood will be drawn, DEXA-scans will be performed and questionnaires will be collected. This design enables comparison between patients on study treatment and standard of care (first 18 months) and within patients before and during treatment (whole trial). Main outcome is annualized liver growth rate compared between standard of care and study treatment. Secondary outcomes are PLD disease severity, change in liver growth within individuals and (serious) adverse events. The study is designed as a prospective open-label study with blinded endpoint assessment (PROBE).

Discussion

In this trial, we combined the expertise of hepatologist, nephrologists and gynecologists to study the effect of leuprorelin on liver growth in PLD. In this way, we hope to stop liver growth, reduce symptoms and reduce the need for liver transplantation in severe PLD.

Trial registration Eudra CT number 2020-005949-16, registered at 15 Dec 2020. https://www.clinicaltrialsregister.eu/ctr-search/search?query=2020-005949-16.

Variability of disease activity in patients with hereditary angioedema type 1/2: longitudinal data from the Icatibant Outcome Survey

BACKGROUND

Hereditary angioedema due to C1 inhibitor deficiency (HAE-1/2) is a chronic and debilitating disease. The unpredictable clinical course represents a significant patient burden.

OBJECTIVE

To analyse longitudinal registry data from the Icatibant Outcome Survey (IOS) in order to characterize temporal changes in disease activity in patients with HAE-1/2.

METHODS

Icatibant Outcome Survey (NCT01034969) is an international observational registry monitoring the clinical outcomes of patients eligible for icatibant treatment. The current analyses are based on data collected between July 2009 and July 2019. Retrospective data for attacks recorded in the 12 months prior to IOS enrolment and for each 12-month period up to 7 years were analysed.

RESULTS

Included patients reported angioedema attacks without long-term prophylaxis (LTP; n = 315) and with LTP (n = 292) use at the time of attack onset. Androgens were the most frequently used LTP option (80.8%). At the population level, regardless of LTP use, most patients (52-80%) reporting <5 attacks in Year 1 continued experiencing this rate; similarly, many patients (25-76%) who reported high attack frequency continued reporting ≥10 attacks/year. However, year on year, 31-51% of patients experienced notable changes (increase/decrease of ≥5 attacks) in annual attack frequency. Of patients who reported an absolute change of ≥10 attacks from Year 1 to 2, 17-50% continued to experience a change of this magnitude in subsequent years.

CONCLUSION

At the population level, attack frequency was generally consistent over 7 years. At the small group level, 28.8-34.5% of patients reported a change in attack frequency of ≥5 attacks from Year 1 to Year 2; up to half of these patients continued to experience this magnitude of variation in disease activity in later years, reflecting high intra-patient variability.

PIK3CA-related overgrowth spectrum (PROS): new insight in known diseases

The overgrowth syndromes related to phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) are grouped under the concept of PROS (PIK3CA-related overgrowth spectrum). It is a heterogeneous group of diseases, considered a rare disease (ORPHA: 530313), which combines the presence of vascular malformations with segmental overgrowth of some parts of the body. All these diseases are caused by mutations in the gene that encodes for the alpha subunit of PI3K. These mutations are somatic and take place during the embryonic stage. Depending on the stage of embryonic development and the affected germ layers, the phenotype will be very different, from syndromes with extensive involvement to isolated forms. Although there are clinical criteria, identification of the mutation by biopsy, although complex, confirms the diagnosis. The objective of the present study is to review the pathophysiological, clinical, diagnostic, and therapeutic aspects of PROS, in order to optimize its identification.

Predictors for incomplete response to ursodeoxycholic acid in primary biliary cholangitis. Data from a national registry of liver disease

Background

The current standard of treatment in primary biliary cholangitis (PBC) is ursodeoxycholic acid (UDCA), although a considerable proportion of patients show incomplete response resulting in disease progression.

Objective

This study aimed to assess the prevalence of incomplete response to UDCA and determine associated patients' characteristics.

Methods

Patients with PBC as main diagnosis were included from a national multicentric patient registry—Liver.pt. Main endpoints included incomplete response to UDCA treatment according to Barcelona, Paris I and Paris II criteria, Globe and UK PBC scores and the association between baseline characteristics and incomplete response according to Paris II criteria.

Results

A total of 434 PBC patients were identified, with a mean age of 55 years and 89.2% females. Nearly half of patients were asymptomatic at diagnosis and 93.2% had positive anti‐mitochondrial antibodies. Almost all patients (95.6%) had been prescribed at least one drug for PBC treatment. At the last follow‐up visit, 93.3% were under treatment of which 99.8% received UDCA. Incomplete response to UDCA was observed in 30.7%, 35.3%, 53.7% and 36.4% of patients according to Barcelona, Paris I, Paris II criteria and Globe score, respectively. After adjusting for age and sex, and accordingly to Paris II criteria, the risk for incomplete biochemical response was 25% higher for patients with cirrhosis at diagnosis (odds ratio [OR] = 1.25; 95% confidence interval [95%CI]: 1.02–1.54; p = 0.033) and 35% (95%CI:1.06–1.72; p = 0.016) and 5% (OR = 1.05; 95%CI:1.01–1.10; p = 0.013) for those with elevated gamma‐glutamyl transferase (GGT) and alkaline phosphatase (ALP).

Conclusion

A considerable proportion of patients showed incomplete biochemical response to UDCA treatment according to Paris II criteria. Cirrhosis, elevated GGT and ALP at diagnosis were identified as associated risk factors for incomplete response. Early identification of patients at risk of incomplete response could improve treatment care and guide clinical decision to a more careful patient monitorization.

Summarise the established knowledge on this subject

Primary biliary cholangitis is a liver disease that can progress to end‐stage liver disease, with premature death or need for liver transplantation.

Treatment with ursodeoxycholic acid (UDCA) significantly increases liver transplant‐free survival. However, incomplete response to UDCA reduces this beneficial effect.

What are the significant and/or new findings of this study?

By evaluating prevalence and risk factors for UDCA incomplete response through a large multicentric national registry it was found that 53.7% of patients were incomplete responders, according to Paris II criteria, with cirrhosis, elevated gamma‐glutamyl transferase and alkaline phosphatase at diagnosis as the main risk factors.

These findings suggest that patients diagnosed at an advanced stage should be closely monitored and might benefit from novel therapies to improve outcomes if incomplete response is present.

Lessons learned from hemolytic uremic syndrome registries: recommendations for implementation

BACKGROUND

Hemolytic uremic syndrome (HUS) is a rare condition which diagnosed with the triad of thrombocytopenia, microangiopathic hemolytic anemia, and acute renal injury. There is a high requirement for research to discover treatments. HUS registries can be used as an important information infrastructure. In this study, we identified and compared the different features of HUS registries to present a guide for the development and implementation of HUS registries.

RESULTS

The purposes of registries were classified as clinical (9 registries), research (7 registries), and epidemiological (5 registries), and only 3 registries pursued all three types of purposes. The data set included demographic data, medical and family history, para-clinical and diagnostic measures, treatment and pharmacological data, complications, and outcomes. The assessment strategies of data quality included monthly evaluation and data audit, the participation of physicians to collect data, editing and correcting data errors, increasing the rate of data completion, following guidelines and data quality training, using specific data quality indicators, and real-time evaluation of data at the time of data entry. 8 registries include atypical HUS patients, and 7 registries include all patients regardless of age. Only two registries focused on children. 4 registries apply prospective and 4 applied both prospective, and retrospective data collection. Finally, specialized hospitals were the main data source for these registries.

CONCLUSION

Based on the findings, we suggested a learning framework for developing and implementing an HUS registry. This framework includes lessons learned and suggestions for HUS registry purposes, minimum data set, data quality assurance, data collection methods, inclusion and exclusion criteria as well as data sources. This framework can help researchers develop HUS registries.

Epidemiology of autosomal-dominant polycystic liver disease in Olmsted county

Background & Aims

Isolated autosomal-dominant polycystic liver disease (ADPLD) is generally considered a rare disease. However, the frequency of truncating mutations to ADPLD genes in large, population sequencing databases is 1:496. With the increasing use of abdominal imaging, incidental detection of hepatic cysts and ADPLD has become more frequent. The present study was performed to ascertain the incidence and point prevalence of ADPLD in Olmsted County, MN, USA, and how these are impacted by the increasing utilisation of abdominal imaging.

Methods

The Rochester Epidemiology Project and radiology databases of Mayo Clinic and Olmsted Medical Center were searched to identify all subjects meeting diagnostic criteria for definite, likely, or possible ADPLD. Annual incidence rates were calculated using incident cases during 1980–2016 as numerator, and age- and sex-specific estimates of the population of Olmsted County as denominator. Point prevalence was calculated using prevalence cases as numerator, and age- and sex-specific estimates of the population of Olmsted County on 1 January 2010 as denominator.

Results

The incidence rate and point prevalence of combined definite and likely ADPLD were 1.01 per 100,000 person-years and 9.5 per 100,000 population, respectively. Only 15 of 35 definite and likely incident ADPLD cases had received a diagnostic code, and only 8 had clinically significant hepatomegaly. The incidence rates were much higher when adding possible cases, mainly identified through radiology databases, particularly in recent years and in older patients because of the increased utilisation of imaging studies.

Conclusions

Clinically significant isolated ADPLD is a rare disease with a prevalence <1:10,000 population. The overall prevalence of ADPLD, however, to a large extent not clinically significant, is likely much higher and closer to the reported genetic prevalence.

Lay summary

Isolated autosomal-dominant polycystic liver disease (ADPLD) is generally considered a rare disease. However, we demonstrate that it is a relatively common disease, which is rarely (<1:10,000 population) clinically significant.

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Isolated autosomal-dominant polycystic liver disease (ADPLD) is generally considered a rare disease.

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Truncating mutations to ADPLD genes are fairly common (1:496) in large, population sequencing databases.

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We identified 35 individuals meeting diagnostic criteria for definite or likely ADPLD and 99 additional patients with possible ADPLD.

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The point prevalence of definite or likely ADPLD on 01/01/2010 was 9.5/100,000 or 36.0/100,000 population if adding possible cases.

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Clinically significant isolated ADPLD is rare (<1:10,000 population), but the overall prevalence is likely much higher.

Novel GANAB variants associated with polycystic liver disease

BACKGROUND

Polycystic liver disease (PLD) is an inherited disorder characterized by numerous cysts in the liver. Autosomal dominant polycystic kidney and liver disease (ADPKD and ADPLD, respectively) have been linked to pathogenic GANAB variants. GANAB encodes the α-subunit of glucosidase II (GIIα). Here, we report the identification of novel GANAB variants in an international cohort of patients with the primary phenotype of PLD using molecular inversion probe analysis.

RESULTS

Five novel GANAB variants were identified in a cohort of 625 patients with ADPKD or ADPLD. In silico analysis revealed that these variants are likely to affect functionally important domains of glucosidase II α-subunit. Missense variant c.1835G>C p.(Arg612Pro) was predicted to disrupt the structure of the active site of the protein, likely reducing its activity. Frameshift variant c.687delT p.(Asp229Glufs*60) introduces a premature termination codon predicted to have no activity. Two nonsense variants (c.2509C>T; p.(Arg837*), and c.2656C>T; p.(Arg886*)) and splice variant c.2002+1G>C, which causes aberrant pre-mRNA splicing and affecting RNA processing, result in truncated proteins and are predicted to cause abnormal binding of α- and β-subunits of glucosidase II, thus affecting its enzymatic activity. Analysis of glucosidase II subunits in cell lines shows expression of a truncated GIIα protein in cells with c.687delT, c.2509C>T, c.2656C>T, and c.2002+1G>C variants. Incomplete colocalization of the subunits was present in cells with c.687delT or c.2002+1G>C variants. Other variants showed normal distribution of GIIα protein.

CONCLUSIONS

We identified five novel GANAB variants associated with PLD in both ADPKD and ADPLD patients supporting a common pathway in cystogenesis. These variants may lead to decreased or complete loss of enzymatic activity of glucosidase II which makes GANAB a candidate gene to be screened in patients with an unknown genetic background.

Current HHT genetic overview in Spain and its phenotypic correlation: data from RiHHTa registry

BACKGROUND

Hereditary hemorrhagic telangiectasia (HHT) is a rare vascular disease with autosomal dominant inheritance. Disease-causing variants in endoglin (ENG) and activin A receptor type II-like 1 (ACVRL1) genes are detected in more than 90% of cases submitted to molecular diagnosis.

METHODS

We used data from the RiHHTa (Computerized Registry of Hereditary Hemorrhagic Telangiectasia) registry to describe genetic variants and to assess their genotype-phenotype correlation among HHT patients in Spain.

RESULTS

By May 2019, 215 patients were included in the RiHHTa registry with a mean age of 52.5 ± 16.5 years and 136 (63.3%) were women. Definitive HHT diagnosis defined by the Curaçao criteria were met by 172 (80%) patients. Among 113 patients with genetic test, 77 (68.1%) showed a genetic variant in ACVRL1 and 36 (31.8%) in ENG gene. The identified genetic variants in ACVRL1 and ENG genes and their clinical significance are provided. ACVRL1 mutations were more frequently nonsense (50%) while ENG mutations were more frequently, frameshift (39.1%). ENG patients were significantly younger at diagnosis (36.9 vs 45.7 years) and had pulmonary arteriovenous malformations (AVMs) (71.4% vs 24.4%) and cerebral AVMs (17.6% vs 2%) more often than patients with ACVRL1 variants. Patients with ACVRL1 variants had a higher cardiac index (2.62 vs 3.46), higher levels of hepatic functional blood tests, and anemia (28.5% vs 56.7%) more often than ENG patients.

CONCLUSIONS

ACVRL1 variants are more frequent than ENG in Spain. ACVRL1 patients developed symptomatic liver disease and anemia more often than ENG patients. Compared to ACVRL1, those with ENG variants are younger at diagnosis and show pulmonary and cerebral AVMs more frequently.

Establishing Patient Registries for Rare Diseases: Rationale and Challenges

Globally, an estimated 350 million people are affected by a rare disease diagnosis. Knowledge limitations persist for the majority of rare conditions due to systemic and structural challenges in healthcare and research. Disease-specific patient populations are often small and geographically dispersed; funding support for research is restricted; and diagnostic delays are common due to disease complexities, limited medical training for practitioners, and evolving foundational knowledge related to disease characterization. Patient registries can be effective, convenient, and cost-efficient tools to support documentation of the natural history of a disease, centering patients as research partners in the process while uniting rare communities around a common initiative. Current global trends towards innovative and patient-centered healthcare are enabling patient registries to increasingly emerge as valuable tools for use within rare disease research and drug development. This article describes the value of and rationale for establishing rare disease patient registries and the considerations and challenges that stakeholders, such as researchers, industry, health care providers, and patient community organizations, may encounter.

Factors Influencing the Generation of Evidence from Simple Data Held in International Rare Disease Patient Registries

BACKGROUND

Rare diseases (defined as affecting < 1 in 2000 Europeans) may collectively affect up to approximately 8% of the population. The low prevalence of individual diseases limits patient studies and data collection is a key challenge; international rare disease patient registries are essential for optimal data collection and research. Registry data achieves value when research conducted on them are published-this is termed evidence generation.

OBJECTIVE

The aim of this study was to examine selected factors and their association with evidence generation, via scientific publication, from international rare disease patient registry data.

METHODS

All international rare disease patient registries listed in the Orphanet 2018 report were analysed. Rates of scientific publications were compared by funding stream, disease area and registry size using multivariable regression analyses. Publication characteristics, such as novelty of findings, were also compared by registry funding stream, disease area and duration of operation.

RESULTS

Privately funded registries had approximately two to four times higher rates of scientific publication compared with publically funded registries, with adjusted rate ratios of 1.85 (95% confidence interval [CI] 1.07-3.22) and 4.18 (95% CI 2.54-6.87) for private not-for-profit and private for-profit funding, respectively. The inclusion of outcomes, use of pharmaceutical medicines, novel findings and citation rate for publications generated from patient registries with any private funding was not significantly different from those attributed to only publicly funded registries.

CONCLUSION

The results of this study indicate that privately funded international rare disease patient registries produce significantly more evidence than their publicly funded counterparts. Examination of the quality indicators of these publications showed they were of the same high quality as those generated from publicly funded patient registry data.

Estrogen-Containing Oral Contraceptives Are Associated With Polycystic Liver Disease Severity in Premenopausal Patients

The association between estrogen-containing oral contraceptives and history of pregnancies with disease severity in women with polycystic liver disease (PLD) is unclear. We performed a cross-sectional cohort study to assess this association by selecting female patients with PLD of which imaging was available prior to any liver volume-reducing therapy. Patients received a questionnaire to collect detailed information on estrogen use and pregnancies. Preplanned subgroup analyses were performed on premenopausal and postmenopausal patients. The questionnaire was returned by 287 of 360 selected patients (80%). There was no significant association between estrogen-containing oral contraceptives and height-adjusted total liver volume (hTLV) in the total group (P = 0.06) and postmenopausal subgroup (P = 0.7). By contrast, each year of exposure corresponds with a 1.45% higher hTLV (P = 0.02) in the premenopausal subgroup, equivalent to a 15.5% higher hTLV for every 10 years of use. Pregnancy duration was not associated with hTLV. In conclusion, patients with PLD should avoid exogenous estrogens.

Position statement on access to care in rare liver diseases: advancements of the European reference network (ERN) RARE-LIVER

The European Reference Network for rare liver diseases (ERN RARE-LIVER) is a Europe-wide network of paediatric and adult hepatologists from expert centres in close collaboration with patient advocates from the various disease-areas covered in our ERN. The ERN is focused on providing more equitable care across Europe and creates a network of both medical specialists and patient experts in rare liver disease. This position paper summarizes the achievements of the first year and plots the route for the near future for ERN RARE-LIVER, as discussed during a strategy meeting that took place 27 and 28 February 2018 in Nijmegen, the Netherlands. ERN RARE-LIVER has established itself as a group with experts, hospitals and patients. One of the tools to improve communication is the clinical patient management system (CPMS) that allows access to expert consultation by European physicians confronted with a patient with rare liver disease. ERN RARE-LIVER will function as the platform to improve healthcare by initiating registries, foster research efforts and coordinate development of clinical guidelines in Europe.

Severity in polycystic liver disease is associated with aetiology and female gender: Results of the International PLD Registry

BACKGROUND & AIMS

Polycystic liver disease (PLD) occurs in two genetic disorders, autosomal-dominant polycystic kidney disease (ADPKD) and autosomal-dominant polycystic liver disease (ADPLD). The aim of this study is to compare disease severity between ADPKD and ADPLD by determining the association between diagnosis and height-adjusted total liver volume (hTLV).

METHODS

We performed a cross-sectional analysis with hTLV as endpoint. Patients were identified from the International PLD Registry (>10 liver cysts) and included in our analysis when PLD diagnosis was made prior to September 2017, hTLV was available before volume-reducing therapy (measured on computed tomography or magnetic resonance imaging) and when patients were tertiary referred. Data from the registry were retrieved for age, diagnosis (ADPKD or ADPLD), gender, height and hTLV.

RESULTS

A total of 360 patients (ADPKD n = 241; ADPLD n = 119) met our inclusion criteria. Female ADPKD patients had larger hTLV compared with ADPLD (P = 0.008). In a multivariate regression analysis, ADPKD and lower age at index CT were independently associated with larger hTLV in females, whereas in males a higher age was associated with larger hTLV. Young females (≤51 years) had larger liver volumes compared with older females (>51 years) in ADPKD.

CONCLUSION

Aetiology is presented as a new risk factor associated with PLD severity. Young females with ADPKD represent a subgroup of PLD patients with the most severe phenotype expressed in hTLV.

Drug holiday in patients with polycystic liver disease treated with somatostatin analogues

BACKGROUND

Somatostatin analogues (SAs) reduce liver volume and relief symptoms in polycystic liver disease (PLD). Its effect wears off after continuing therapy suggesting development of SA tolerance in patients on chronic therapy. We postulate that a drug holiday resensitizes the liver to its acute pharmacological effects. Therefore, this study examines the liver volume-reducing effect of SAs after a drug holiday.

METHODS

Patients were identified from the International PLD Registry and included in our analysis when (1) treated with SAs during two cycles separated by a drug holiday and (2) height-adjusted total liver volume (hTLV) was available at start and end of each cycle. For our primary outcome we compared the effect of SAs (in % per 6 months) on hTLV between the first and second treatment cycle.

RESULTS

In 34 patients, initial liver volume-reducing effect was similar to that after rechallenge [-2.6% per 6 months (interquartile range, -3.8-0.8) versus -1.6% per 6 months (interquartile range, -3.1-1.1), p = 0.510]. Cessation of treatment led to a rebound effect, but liver volume remained stable compared with the baseline with intermittent therapy in responders to SA [-0.6% (interquartile range, -7.4-5.7) after 46.5 months].

CONCLUSIONS

PLD patients treated with SAs benefit from retreatment after a drug holiday. The significant increase of liver volume after cessation of treatment complicates widespread use of a drug holiday as new treatment strategy. Our results contribute to a better understanding of the pharmacological effect of SAs and help to identify patients who might benefit.

Computerized registry of patients with hemorrhagic hereditary telangiectasia (RiHHTa Registry) in Spain: Objectives, methods, and preliminary results

INTRODUCTION

Hereditary hemorrhagic telangiectasia (HHT) is a rare disease with autosomal dominant inheritance that causes systemic vascular affectation.

MATERIAL AND METHOD

After development a multicentric Spanish national registry, called RiHHTa, main clinical manifestations and diagnostic procedures of the first patients introduced are described.

RESULTS

141 patients were included, of which 91 (64.5%) were women. The mean age at diagnosis was 42 years. Mutations in the ACVRL1 gene predominated over the ENG gene. The initial symptom was recurrent epistaxis in 130 (92.2%) patients and in three (2.1%), brain abscess. Pulmonary arteriovenous (AV) fistula were detected in 36 (45%) of the 79 patients who underwent thoracic CT angiography. The contrast echocardiography detected very few bubbles (grade I) or none, in 36 (45%) of these 79 affected patients. In 43 (67.2%) of the 64 patients with an abdominal CT angiography, hepatic vascular malformations were detected, mostly telangiectasias, AV and arterio-portal fistula, and extrahepatic in 14 (10%) subjects. More than half of the patients were screened for the presence of brain arteriovenous malformations which was found in 3.9% of them. The upper part of the intestinal tube was the most (95%) affected region.

CONCLUSION

The RiHHTa Registry allows improving the management of patients with HHT. An inadequate use of thoracic CT angiography and the usefulness of abdominal CT angiography has been detected in order to define subtypes of hepatic vascular involvement and detect extrahepatic vascular involvement.

National information system for rare diseases with an approach to data architecture: A systematic review

The study aims to systematically review literature on the rare diseases information system to identify architecture of this system from a data perspective. The search for relevant English language articles, based on keywords in title, abstract, Mesh and Emtree terms, was done in Pubmed and Embase (from 1980 to June 2017), Scopus, Science Direct and Cochran (from 1980 to July 2017). Articles were selected if they addressed data architecture of information systems with a focus on rare disease, and if at least one of their objectives dealt with design, implementation, and development of rare diseases information systems. Thirty-five studies met the inclusion criteria. The findings were categorized into six groups. This first group addressed organizations acting as data generators, data users, and data governors. The second group was related to data sources and databases. Datasets and data elements formed the third group of findings, including common datasets, specific datasets, and complementary datasets. The fourth group of findings was in relation to data standards. Data sharing and interactions among relevant bodies included the fifth group of the findings. The last group of findings was pertinent to procedures and criteria used for checking the quality of data, as cross review checking was a main procedure assessing the accuracy, consistency, and completeness of data. Design and development of an integrated information system for rare diseases considering data architecture principles in practice could help eliminating issues with management of rare diseases through facilitating sharing information and experiences.

Research protocol: The initiation, design and establishment of the Global Angelman Syndrome Registry

BACKGROUND

Angelman syndrome (AS) is a rare neurodevelopmental disorder affecting between 1 in 15 000 and 1 in 24 000 individuals. The condition results in severe developmental and expressive language delays, motor impairments and a unique behavioural phenotype consisting of excessive laughter, smiling and sociability. While many studies have contributed knowledge about the causes and natural history of the syndrome, large scale longitudinal studies are required to advance research and therapeutics for this rare syndrome.

METHOD

This article describes the protocol for the Global Angelman Syndrome Registry, and some initial findings. Due to the rarity of AS and the variability in symptom presentation, the registry team will strive for complete case ascertainment. Parents and caregivers will submit data to the registry via a secure internet connection. The registry consists of 10 modules that cover patient demographics; developmental, diagnostic, medical and surgical history, behaviour and development, epilepsy, medications and interventions and sleep.

RESULTS

Since its launch at https://angelmanregistry.info in September 2016, almost 470 individuals with AS have been signed up to the registry worldwide: 59% are from North and South America, 23% are from Europe, 17% are from the Asia Pacific region and 1% are from the Middle East or Africa. The majority of registrants are children, with only 16% aged over 20 years. Most participants indicated a chromosome deletion (76%), with fewer participants indicating a mutation, uniparental disomy or imprinting defect (20%).

CONCLUSION

Findings indicate a need to consider recruitment strategies that target caregivers of older children and adults, and parents and caregivers from non-English speaking backgrounds.

Clinical management of polycystic liver disease

A 41-year old female underwent a computed tomography (CT) scan in 2010 because of symptoms suggestive of appendicitis. Incidentally, multiple liver lesions characterised as cysts were detected. The presence of small to medium sized liver cysts (diameter between <1 cm and 4 cm) in all liver segments (>100 cysts) and absence of kidney cysts in the context of normal renal function led to the clinical diagnosis of autosomal dominant polycystic liver disease (ADPLD). Five years later she was referred to the outpatient clinic with increased abdominal girth, pain in the right upper abdomen and right flank, and early satiety. She had difficulties bending over and could neither cut her toenails nor tie her shoe laces. In her early twenties she had used oral contraception for five years. She has been pregnant twice. Clinical examination showed an enlarged liver reaching into the right pelvic region and crossing the midline of the abdomen. Laboratory testing demonstrated increased gamma-glutamyl transferase (80 IU/L, normal <40 IU/L) and alkaline phosphatase (148 IU/L, normal <100 IU/L) levels. Bilirubin, albumin and coagulation times were within the normal range. A new CT scan in 2015 was compatible with an increased number and size of liver cysts. The diameter of cysts varied between <1 cm and 6 cm (anatomic distribution shown [Fig. 2B]). There were no signs of hepatic venous outflow obstruction, portal hypertension or compression on the biliary tract. Height-adjusted total liver volume (htTLV) increased from 2,667 ml/m in 2012 to 4,047 ml/m in 2015 (height 172 cm). The case we present here is not uncommon, and prompts several relevant questions.