A new variant in the ZCCHC8 gene: diverse clinical phenotypes and expression in the lung.

Introduction: Pulmonary fibrosis is a severe disease which can be familial. A genetic cause can only be found in ∼40% of families. Searching for shared novel genetic variants may aid the discovery of new genetic causes of disease. Methods: Whole-exome sequencing was performed in 152 unrelated patients with a suspected genetic cause of pulmonary fibrosis from the St Antonius interstitial lung disease biobank. Variants of interest were selected by filtering for novel, potentially deleterious variants that were present in at least three unrelated pulmonary fibrosis patients. Results: The novel c.586G>A p.(E196K) variant in the ZCCHC8 gene was observed in three unrelated patients: two familial patients and one sporadic patient, who was later genealogically linked to one of the families. The variant was identified in nine additional relatives with pulmonary fibrosis and other telomere-related phenotypes, such as pulmonary arterial venous malformations, emphysema, myelodysplastic syndrome, acute myeloid leukaemia and dyskeratosis congenita. One family showed incomplete segregation, with absence of the variant in one pulmonary fibrosis patient who carried a PARN variant. The majority of ZCCHC8 variant carriers showed short telomeres in blood. ZCCHC8 protein was located in different lung cell types, including alveolar type 2 (AT2) pneumocytes, the culprit cells in pulmonary fibrosis. AT2 cells showed telomere shortening and increased DNA damage, which was comparable to patients with sporadic pulmonary fibrosis and those with pulmonary fibrosis carrying a telomere-related gene variant, respectively. Discussion: The ZCCHC8 c.586G>A variant confirms the involvement of ZCCHC8 in pulmonary fibrosis and short-telomere syndromes and underlines the importance of including the ZCCHC8 gene in diagnostic gene panels for these diseases.

Genetic Variant Overlap Analysis Identifies Established and Putative Genes Involved in Pulmonary Fibrosis.

In only around 40% of families with pulmonary fibrosis (PF) a suspected genetic cause can be found. Genetic overlap analysis of Whole Exome Sequencing (WES) data may be a powerful tool to discover new shared variants in novel genes for PF. As a proof of principle, we first selected unrelated PF patients for whom a genetic variant was detected (n = 125) in established PF genes and searched for overlapping variants. Second, we performed WES (n = 149) and identified novel potentially deleterious variants shared by at least two unrelated PF patients. These variants were genotyped in validation cohorts (n = 2748). In 125 unrelated patients, a potentially deleterious variant was detected in known PF genes of which 15 variants in six genes overlapped, involving 51 patients. Overlap analysis of WES data identified two novel variants of interest: TOM1L2 c.421T > C p.(Y141H) and TDP1c.1373dupG p.(S459fs*5), neither gene had been related to pulmonary fibrosis before. Both proteins were present in the alveolar epithelium. No apparent characteristics of telomere disease were observed. This study underlines the potential of searching for overlapping rare potentially deleterious variants to identify disease-associated variants and genes. A previously unreported variant was found in two putative new PF genes, but further research is needed to determine causality.

Optimizing Screening for Early Disease Detection in Familial Pulmonary Fibrosis (FLORIS): A Prospective Cohort Study Design.

Background: Familial pulmonary fibrosis (FPF) can be defined as pulmonary fibrosis in two or more first-degree family members. The first-degree family members of FPF patients are at high risk of developing FPF and are eligible for screening. Reproducible studies investigating risk factors for disease are much needed. Methods: Description of the screening study protocol for a single-center, prospective cohort study; the study will include 200 asymptomatic, first-degree family members of patients with FPF who will undergo three study visits in two years. The primary objective is determining the diagnostic value of parameters for detection of early FPF; the secondary objectives are determining the optimal timing of the screening interval and gaining insight into the natural history of early FPF. The presence of interstitial lung disease (ILD) changes on high-resolution computed tomography of the chest is indicative of preclinical ILD; the changes are determined at baseline. The comparison between the group with and without ILD changes is made for clinical parameters (pulmonary function, presence of digital clubbing, presence of Velcro-like crackles, blood count, liver- and kidney-function testing, patient-reported cough and dyspnea score) and exploratory parameters. Discussion: This study will be the first large-size, prospective, longitudinal cohort study for yearly screening of asymptomatic family members of FPF patients investigating the diagnostic value of parameters, including lung function, to detect early FPF. More effective screening strategies could advance early disease detection.

Pulmonary Hypertension Associated Genetic Variants in Sarcoidosis Associated Pulmonary Hypertension.

BACKGROUND: Pulmonary hypertension (PH) is a severe complication of sarcoidosis in a minority of patients. Several genetic defects are known to cause hereditary or sporadic PH, but whether variants in PH-associated genes are also involved in sarcoidosis-associated PH (SAPH) is unknown. METHODS: 40 patients with SAPH were individually matched to 40 sarcoidosis patients without PH (SA). Whole exome sequencing was performed to identify rare genetic variants in a diagnostic PH gene panel of 13 genes. Additionally, an exploratory analysis was performed to search for other genes of interest. From 572 genes biologically involved in PH pathways, genes were selected in which at least 15% of the SAPH patients and no more than 5% of patients without PH carried a rare variant. RESULTS: In the diagnostic PH gene panel, 20 different rare variants, of which 18 cause an amino-acid substitution, were detected in 23 patients: 14 SAPH patients carried a variant, as compared to 5 SA patients without PH (p = 0.018). Most variants were of yet unknown significance. The exploratory approach yielded five genes of interest. First, the NOTCH3 gene that was previously linked to PH, and furthermore PDE6B, GUCY2F, COL5A1, and MMP21. CONCLUSIONS: The increased frequency of variants in PH genes in SAPH suggests a mechanism whereby the presence of such a genetic variant in a patient may increase risk for the development of PH in the context of pulmonary sarcoidosis. Replication and studies into the functionality of the variants are required for further understanding the pathogenesis of SAPH.

Rationale, design and initial results of an educational intervention to improve provider-initiated HIV testing in primary care.

OBJECTIVES: In the Netherlands, general practitioners (GPs) perform two-thirds of sexually transmitted infection (STI) consultations and diagnose one-third of HIV infections. GPs are, therefore, a key group to target to improve provider-initiated HIV testing. We describe the design and implementation of an educational intervention to improve HIV testing by Amsterdam GPs and explore trends in GPs' testing behaviour. METHODS: Interactive sessions on HIV and STI using graphical audit and feedback started in 2015. Participating GPs developed improvement plans that were evaluated in follow-up sessions. Laboratory data on STI testing by Amsterdam GPs from 2011 to 2017 were collected for graphical audit and feedback and effect evaluation. The primary outcome was the HIV testing rate: number of HIV tests per 10 000 person-years (PY). Secondary endpoints were chlamydia and gonorrhoea testing rates and HIV positivity ratios. RESULTS: Since 2015, 41% of GPs participated. HIV testing rate declined from 2011 to 2014 (from 175 to 116 per 10 000 PY), more in women than men (176 to 101 versus 173 to 132), and stabilized from 2015 to 2017. The HIV positivity ratio declined from 0.8% in 2011 to 0.5% in 2017. From 2011 to 2017, chlamydia and gonorrhoea testing rates declined in women (from 618 to 477 per 10 000 PY) but remained stable in men (from 270 to 278). CONCLUSIONS: The stabilization of the downward trend in HIV testing coincided with this educational intervention. Follow-up data are needed to formally assess the intervention's impact on GP testing behaviour whilst considering contextual factors and secular trends.

[HIV positive patients visit an increasing number of physicians]. / Hiv-patiënten zien steeds meer dokters.

The population of people living with HIV is ageing. As a result, an increasing proportion of people on combination antiretroviral therapy will experience comorbidities and polypharmacy, with the risk of drug-drug interactions. These comorbidities will also be treated by physicians who are not specialised in HIV. Moreover, early diagnosis and treatment improve the prognosis of HIV infection, but 11% of the people living with HIV are currently undiagnosed. Therefore, physicians should be alert to the possibility of HIV also with regard to older adults. Since risk assessment may be challenging, testing for HIV upon diagnosis of an indicator condition could prove a useful strategy to enhance earlier diagnosis for all physicians.