Estimation of ENPP1 deficiency genetic prevalence using a comprehensive literature review and population databases.

BACKGROUND: ENPP1 Deficiency-caused by biallelic variants in ENPP1-leads to widespread arterial calcification in early life (Generalized Arterial Calcification of Infancy, GACI) or hypophosphatemic rickets in later life (Autosomal Recessive Hypophosphatemic Rickets type 2, ARHR2). A prior study using the Exome Aggregation Consortium (ExAC)-a database of exomes obtained from approximately 60,000 individuals-estimated the genetic prevalence at approximately 1 in 200,000 pregnancies. METHODS: We estimated the genetic prevalence of ENPP1 Deficiency by evaluating allele frequencies from a population database, assuming Hardy-Weinberg equilibrium. This estimate benefitted from a comprehensive literature review using Mastermind ( https://mastermind.genomenon.com/ ), which uncovered additional variants and supporting evidence, a larger population database with approximately 140,000 individuals, and improved interpretation of variants as per current clinical guidelines. RESULTS: We estimate a genetic prevalence of approximately 1 in 64,000 pregnancies, thus more than tripling the prior estimate. In addition, the carrier frequency of ENPP1 variants was found to be highest in East Asian populations, albeit based on a small sample. CONCLUSION: These results indicate that a significant number of patients with ENPP1 Deficiency remain undiagnosed. Efforts to increase disease awareness as well as expand genetic testing, particularly in non-European populations are warranted, especially now that clinical trials for enzyme replacement therapy, which proved successful in animal models, are underway.

Pooled microbiological findings and efficacy outcomes by pathogen in adults with community-acquired bacterial pneumonia from the Lefamulin Evaluation Against Pneumonia (LEAP) 1 and LEAP 2 phase 3 trials of lefamulin versus moxifloxacin.

OBJECTIVES: Lefamulin, a pleuromutilin antibiotic approved for community-acquired bacterial pneumonia (CABP), was evaluated for microbiological efficacy in a prespecified pooled analysis of LEAP 1 and 2 phase 3 clinical trial data in patients with CABP. METHODS: In LEAP 1, adults (PORT risk class III‒V) received intravenous (IV) lefamulin 150 mg every 12 h (q12h) for 5‒7 days or moxifloxacin 400 mg every 24 h (q24h) for 7 days, with optional IV-to-oral switch. In LEAP 2, adults (PORT II‒IV) received oral lefamulin 600 mg q12h for 5 days or moxifloxacin 400 mg q24h for 7 days. Primary outcomes were early clinical response (ECR) at 96 ± 24 h after treatment start and investigator assessment of clinical response (IACR) 5‒10 days after the last dose. Secondary outcomes included ECR and IACR in patients with a baseline CABP pathogen (detected via culture, urinary antigen testing, serology and/or real-time PCR). RESULTS: Baseline CABP pathogens were detected in 709/1289 patients (55.0%; microbiological intention-to-treat population). The most frequently identified pathogens were Streptococcus pneumoniae (61.9% of patients) and Haemophilus influenzae (29.9%); 25.1% had atypical pathogens and 33.1% had polymicrobial infections. Pathogens were identified most frequently by PCR from sputum, followed by culture from respiratory specimens. In patients with baseline CABP pathogens, ECR rates were 89.3% (lefamulin) and 93.0% (moxifloxacin); IACR success rates were 83.2% and 86.7%, respectively. Results were consistent across CABP pathogens, including drug-resistant isolates and polymicrobial infections. CONCLUSION: Lefamulin is a valuable IV and oral monotherapy option for empirical and directed CABP treatment in adults.

Assessment of surfactant protein A (SP-A) dependent agglutination.

BACKGROUND: Monomers of the collectin surfactant associated protein-A (SP-A) are arranged in trimers and higher oligomers. The state of oligomerization differs between individuals and likely affects SP-A's functional properties. SP-A can form aggregates together with other SP-A molecules. Here we report and assess a test system for the aggregate forming properties of SP-A in serum and broncho-alveolar lavage samples. METHODS: Anti-SP-A antibodies fixed to latex beads bound SP-A at its N-terminal end and allowed the interaction with other SP-A molecules in a given sample by their C-terminal carbohydrate recognition domain (CRD) to agglutinate the beads to aggregates, which were quantified by light microscopy. RESULTS: SP-A aggregation was dependent on its concentration, the presence of calcium, and was dose-dependently inhibited by mannose. Unaffected by the presence of SP-D no aggregation was observed in absence of SP-A. The more complex the oligomeric structure of SP-A present in a particular sample, the better was its capability to induce aggregation at a given total concentration of SP-A. SP-A in serum agglutinated independently of the pulmonary disease; in contrast SP-A in lung lavage fluid was clearly inferior in patients with chronic bronchitis and particularly with cystic fibrosis compared to controls. CONCLUSIONS: The functional status of SP-A with respect to its aggregating properties in serum and lavage samples can be easily assessed. SP-A in lung lavage fluid in patients with severe neutrophilic bronchitis was inferior.

Endogenous hSNM1B/Apollo interacts with TRF2 and stimulates ATM in response to ionizing radiation.

Human SNM1B/Apollo is involved in the cellular response to DNA-damage, however, its precise role is unknown. Recent reports have implicated hSNM1B in the protection of telomeres. We have found hSNM1B to interact with TRF2, a protein which functions in telomere protection and in an early response to ionizing radiation. Here we show that endogenous hSNM1B forms foci which colocalize at telomeres with TRF1 and TRF2. However, we observed that additional hSNM1B foci could be induced upon exposure to ionizing radiation (IR). In live-cell-imaging experiments, hSNM1B localized to photo-induced double-strand breaks (DSBs) within 10s post-induction. Further supporting a role for hSNM1B in the early stages of the cellular response to DSBs, we observed that autophosphorylation of ATM, as well as the phosphorylation of ATM target proteins in response to IR, was attenuated in cells depleted of hSNM1B. These observations suggest an important role for hSNM1B in the response to IR damage, a role that may be, in part, upstream of the central player in maintenance of genome integrity, ATM.