The estimated incidence of cystic fibrosis in Japan

Clinical and Imaging Features of Cystic Fibrosis in Korean Children

Cystic fibrosis (CF) is a fatal hereditary disorder that primarily affects Caucasians and is rare in Asian populations, including Koreans. Diagnosing CF is often challenging and delayed owing to its rarity and its overlapping features with non-CF diseases, ultimately affecting the patient prognosis. Radiologists can provide initial clues for clinically unsuspected cases and play a crucial role in establishing an early childhood diagnosis. This pictorial essay reviews the clinical and imaging features of genetically confirmed CF in Korean children and increases awareness of this rare disease, thereby facilitating early diagnosis.

A comprehensive review of cystic fibrosis in Africa and Asia

Cystic fibrosis (CF) was earlier thought to be a disease prevalent in the West among Caucasians. However, quite a number of recent studies have uncovered CF cases outside of this region, and reported hundreds of unique and novel variant forms of CFTR. Here, we discuss the evidence of CF in parts of the world earlier considered to be rare; Africa, and Asia. This review also highlighted the CFTR mutation variations and new mutations discovered in these regions. This discovery implies that the CF data from these regions were earlier underestimated. The inadequate awareness of the disease in these regions might have contributed towards the poor diagnostic facilities, under-diagnosis or/and under-reporting, and the lack of CF associated health policies. Overall, these regions have a high rate of infant, childhood and early adulthood mortality due to CF. Therefore, there is a need for a thorough investigation of CF prevalence and to identify unique and novel variant mutations within these regions in order to formulate intervention plans, create awareness, develop mutation specific screening kits and therapies to keep CF mortality at bay.

Genetic attributes of Iranian cystic fibrosis patients: the diagnostic efficiency of CFTR mutations in over a decade

Objectives: Cystic fibrosis (CF) is the most prevalent autosomal recessive disorder among Caucasians. Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause this pathology. We, therefore, aimed to describe the CFTR mutations and their geographical distribution in Iran. Method: The mutation spectrum for 87 families from all Iranian ethnicities was collected using ARMS PCR, Sanger sequencing, and MLPA. Results: Mutations were identified in 95.8% of cases. This dataset revealed that the most frequent mutations in the Iranian population were F508del, c.1000C>T, c.1397C>G, c.1911delG, and c.1393-1G>A. In addition, we found weak evidence for Turkey being the possible geographical pathway for introducing CFTR mutations into Iran by mapping the frequency of CFTR mutations. Conclusion: Our descriptive results will facilitate the genetic detection and prenatal diagnosis of cystic fibrosis within the Iranian population.

Cystic Fibrosis Modulator Therapies

Cystic fibrosis (CF) is an inherited multisystemic disease that can cause progressive bronchiectasis, pancreatic endocrine and exocrine insufficiency, distal intestinal obstruction syndrome, liver dysfunction, and other disorders. Traditional therapies focused on the treatment or prevention of damage to each organ system with incremental modalities such as nebulized medications for the lungs, insulin for diabetes, and supplementation with pancreatic enzymes. However, the advent of highly effective modulator therapies that target specific cystic fibrosis transmembrane conductance regulator protein malformations resulting from individual genetic mutations has transformed the lives and prognosis for persons with CF.

Cystic fibrosis with multiple pulmonary arteriovenous malformations: A case report

Cystic fibrosis is an autosomal recessive genetic disorder that damages the exocrine function of the body, resulting in alterations of multiple organs. In the respiratory system, it is known to cause bronchiectasis, recurrent bronchitis, and pneumonia; however, to the best of our knowledge, there are no reported cases of pulmonary arteriovenous malformations associated with this disease. Herein, we report a case of cystic fibrosis with multiple pulmonary arteriovenous malformations. A 16-year-old girl, who has been monitored since childhood for pancreatitis of unknown cause, experienced respiratory symptoms and hypoxemia (PaO2 = 57 mmHg). At 13 years of age, chest computed tomography revealed bronchiectasis, bronchial wall thickening, and tree-in-bud sign. Genetic testing was performed, and the patient was diagnosed with cystic fibrosis. However, the computed tomography scan also showed incidental nodular lesions in the left superior and both the inferior pulmonary lobes, suggesting multiple arteriovenous malformations. Dynamic computed tomography was performed which, confirmed the presence of 3 pulmonary arteriovenous malformations. Coil embolization was performed on all lesions, and the hypoxemia was corrected. Marked hypoxemia in a patient with cystic fibrosis may not be explained only by the presence of bronchiectasis and/or bronchial wall thickening; in such cases, it may be necessary to examine possible additional findings on computed tomography images, such as arteriovenous malformations.

The incidence of bronchiectasis in chronic obstructive pulmonary disease

Bronchiectasis is a common comorbidity in chronic obstructive pulmonary disease (COPD). There are limited data regarding the incidence of bronchiectasis in COPD. The purpose of the study was to use a nationwide database to evaluate the incidence of bronchiectasis in COPD in Taiwan. We used a cohort of 2,000,000 individuals followed from 2005 to 2018. Patients with COPD diagnosed between January 1, 2011, and December 31, 2017, were selected, and those with bronchiectasis before COPD were excluded. In total, 134,366 patients with COPD were enrolled, and propensity score matching was used to ensure homogeneity of baseline characteristics between the COPD and non-COPD groups. The incidence rate of bronchiectasis was higher in the COPD group than in the non-COPD group (87.83 vs 69.80 per 10,000 person-years). The adjusted hazard ratio (1.9; 95% confidence interval 1.75-2.05; P < 0.001) of bronchiectasis indicated that the risk of bronchiectasis was 1.9 times higher for patients with COPD than for patients without COPD. In the COPD group, the age-stratified incidence rates of bronchiectasis increased with age (55.01, 80.92, 101.52, and 105.23 for 40-49, 50-59, 60-69, and over 70 years, respectively). The incidence of bronchiectasis was higher in patients with COPD than in the general population, the risk of bronchiectasis increased with age in COPD, and post-tuberculosis status was an important risk factor for bronchiectasis.

Toward a Broader Understanding of Cystic Fibrosis Epidemiology and Its Impact on Clinical Manifestations

The incidence of cystic fibrosis remains constant in North America and Western Europe is 1 in 3500 live births, but survival and quality of life have improved. The cystic fibrosis population has shifted toward the adult age range with a concomitant shift in the spectrum of complications. Survival increased because of aggressive symptomatic therapy, earlier diagnosis by newborn screening, and the introduction of modulators of the cystic fibrosis transmembrane conductance regulator, so that predicted median survival age is now about 50 years. In the United States, members of low socioeconomic status populations or members of racial or ethnic minorities have benefitted less from these advances.

Congenital absence of the vas deferens with hypospadias or without hypospadias: Phenotypic findings and genetic considerations

Congenital absence of the vas deferens (CAVD) is a major cause of obstructive azoospermia. Mutations of CFTR and ADGRG2 cause the majority of CAVD. Despite this, 10%–20% of CAVD patients remain without a clear genetic diagnosis. Herein, the CFTR and ADGRG2 genes were first sequenced using Sanger sequencing in 50 CAVD patients. Whole-exome sequencing (WES) was used to further identify potential novel genetic causes in CAVD with hypospadias. In total, 29 of 50 CAVD patients carried at least one CFTR mutation, but no ADGRG2 mutation was found. 5T was found to be the most frequent variant in our CAVD populations. Seven CAVD patients with hypospadias were further analyzed using WES. No homozygous or compound heterozygous mutations related to disorders of sex development (DSDs) or male infertility were identified by WES. CAVD with hypospadias presented lower testicular volume (9.71 ± 2.14 ml vs. 14.45 ± 2.93 ml, p &lt; 0.001) and higher FSH level (FSH: 7.28 ± 3.91 IU/L vs. 4.24 ± 1.96 IU/L, p = 0.027) than CAVD without hypospadias. It is worth noting that neither CFTR or ADGRG2 mutation nor homozygous or compound heterozygous gene mutations were identified in seven CAVD cases with hypospadias. However, nine heterozygous or hemizygous mutations were selected as potential pathogenic genes in CAVD with hypospadias. In conclusion, CFTR variants, especially 5T, play a major role in the Chinese CAVD population. CAVD with hypospadias shows relatively lower testicular spermatogenesis, suggesting a different genetic basis or pathogenic factor from cystic fibrosis/CAVD or unilateral renal agenesis/CAVD.

Targeting fibrosis, mechanisms and cilinical trials

Fibrosis is characterized by the excessive extracellular matrix deposition due to dysregulated wound and connective tissue repair response. Multiple organs can develop fibrosis, including the liver, kidney, heart, and lung. Fibrosis such as liver cirrhosis, idiopathic pulmonary fibrosis, and cystic fibrosis caused substantial disease burden. Persistent abnormal activation of myofibroblasts mediated by various signals, such as transforming growth factor, platelet-derived growth factor, and fibroblast growh factor, has been recongized as a major event in the occurrence and progression of fibrosis. Although the mechanisms driving organ-specific fibrosis have not been fully elucidated, drugs targeting these identified aberrant signals have achieved potent anti-fibrotic efficacy in clinical trials. In this review, we briefly introduce the aetiology and epidemiology of several fibrosis diseases, including liver fibrosis, kidney fibrosis, cardiac fibrosis, and pulmonary fibrosis. Then, we summarise the abnormal cells (epithelial cells, endothelial cells, immune cells, and fibroblasts) and their interactions in fibrosis. In addition, we also focus on the aberrant signaling pathways and therapeutic targets that regulate myofibroblast activation, extracellular matrix cross-linking, metabolism, and inflammation in fibrosis. Finally, we discuss the anti-fibrotic drugs based on their targets and clinical trials. This review provides reference for further research on fibrosis mechanism, drug development, and clinical trials.

Molecular Epidemiological Characteristics of Mycobacterium abscessus Complex Derived from Non-Cystic Fibrosis Patients in Japan and Taiwan

Mycobacterium abscessus complex (MABC) is a group of emerging, highly antimicrobial-resistant non-tuberculous mycobacteria. Specific MABC clones are spreading globally in patients with cystic fibrosis (CF); however, associated genomic epidemiology is lacking in East Asia, with very few patients with CF. Here, we investigated MABC populations derived from non-CF patients in Japan and Taiwan. Analysis of whole-genome sequencing data of 220 MABC isolates revealed that 112, 105, and 3 were M. abscessus subsp. abscessus (ABS), M. abscessus subsp. massiliense (MAS), and M. abscessus subsp. bolletii (BOL), respectively. Moreover, >50% of ABS and >70% of MAS were related to four predominant clones in the region. Known mutations conferring macrolide resistance were rare (1.4%) and were not enriched in the predominant clones. Conversely, the macrolide-susceptible erm(41) T28C mutation was significantly enriched in one predominant ABS clone. The most predominant ABS clone was genetically related to the previously described dominant circulating clone (DCC)1 in patients with CF, whereas no isolates were related to DCC2; isolates related to DCC3 were not necessarily predominant in our sample set. We found that the erm(41) T28C mutants spread globally, and some of them reacquired the functional erm(41) gene through both point mutation and recombination. This study revealed predominant MABC clones in Japan and Taiwan and their relationship with the globally superadding clones in the patient community with CF. Our study provides insights into the genetic characteristics of globally dominant and area-specific strains isolated from patients with or without CF and differences between globally spread and regionally specific strains.

IMPORTANCE Members of Mycobacterium abscessus complex (MABC) are frequently isolated from patients. Studies have reported that predominant clones of MABC (known as dominant circulating clones; DCCs) are distributed worldwide and transmitted from humans to humans in patients with cystic fibrosis (CF). However, associated genomic epidemiology has not yet been conducted in East Asia, including Japan and Taiwan, where there are only a few patients with CF. Using whole-genome sequencing data derived from non-CF patients in Japan and Taiwan, we revealed prevalent clones and the incidence of macrolide resistance-associated mutations in the MABC population in this region. We also clarified the associations between these predominant clones and DCCs in the global CF patient community. Our results would assist further studies in elucidating the genetic characteristics of strains isolated from patients with or without CF, the differences between globally spread and regionally specific strains, and the adaptive evolution of MABC within the host.

Real-life Progression of the Use of a Genetic Panel in to Diagnose Neonatal Cholestasis

The study aimed to construct an advanced gene panel to ascertain the genetic etiology of patients with neonatal/infantile intrahepatic cholestasis (NIIC), and test patients with NIIC in a clinical setting.

Multicenter Surveillance of Cystic Fibrosis in Korean Children

Purpose

Methods

Results

Conclusions

Waiting time and mortality rate on lung transplant candidates in Japan: a single-center retrospective cohort study

Background

As lung transplantation (LTX) is a valuable treatment procedure for end-stage pulmonary disease, delayed referral to a transplant center should be avoided. We aimed to conduct a single-center analysis of the survival time after listing for LTX and waitlist mortality in each disease category in a Japanese population.

Methods

We included patients listed for LTX at Tohoku University Hospital from January 2007 to December 2020 who were followed up until March 2021. Pulmonary disease was categorized into the Obstructive, Vascular, Suppurative, Fibrosis, and Allogeneic groups. Risk factors for waitlist mortality were assessed using a Cox proportional hazards model. The Kaplan–Meier method was used to model time to death.

Results

We included 269 LTX candidates. Of those, 100, 72, and 97 patients were transplanted, waiting, and dead, respectively. The median time to LTX and time to death were 796 days (interquartile range [IQR] 579–1056) and 323 days (IQR 129–528), respectively. The Fibrosis group showed the highest mortality (50.9%; p < .001), followed by the Allogeneic (35.0%), Suppurative (33.3%), Vascular (32.1%), and Obstructive (13.1%) groups. The Fibrosis group showed a remarkable risk for waitlist mortality (hazard ratio 3.32, 95% CI 2.11–4.85).

Conclusions

In Japan, the waiting time is extremely long and candidates with Fibrosis have high mortality. There is a need to document outcomes based on the underlying disease for listed LTX candidates to help determine the optimal timing for listing patients based on the estimated local waiting time.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01760-8.

Analysis of Clinical Manifestations, Imaging Features, and Gene Mutation Characteristics of 6 Children with Cystic Fibrosis in China

Objective

To explore the clinical manifestations, imaging features, and gene mutation characteristics of 6 children with cystic fibrosis (CF) so as to improve the understanding and diagnosis awareness of CF in children and reduce the missed diagnosis and misdiagnosis.

Methods

The clinical manifestations, imaging, and gene mutation data of six children with CF were collected and retrospectively analyzed.

Results

Among the 6 cases of CF, there were 4 males and 2 females. Among the 6 children with CF, 5 cases presented with recurrent respiratory tract infection. Etiology suggested 3 cases of Pseudomonas aeruginosa and 2 cases of Staphylococcus aureus. 3 cases had pancreatic exocrine dysfunction, manifested as diarrhea and aliphatic diarrhea, of which 1 case had high lipase in blood examination, and pancreatic ultrasound showed rough and enhanced pancreatic echo, considering pancreatic cystic fibrosis. 2 cases of CF combined with pseudo-Bartter syndrome (PBS); 1 case involved only the biliary tract and started with cholestasis without other systemic involvement. In 2 cases of sweat test, sweat chloride ions were all >60 mmol/L. 3 cases underwent fiberoptic bronchoscopy, and a large number of sticky secretions were visible under the bronchoscopy. CT of the chest revealed thickening of the bronchial wall (3 cases), bronchiectasis (1 case), atelectasis (1 case), and thin bronchial lumen (2 cases). 1 patient was found to have small airway lesions and mosaic perfusion during follow-up. All 6 children with CF underwent genetic testing. A total of 12 CF transmembrane conductance regulator (CFTR) gene mutations were found, of which 4 mutations were not reported in the literature.

Conclusion

CF is a disease caused by CFTR mutation. The incidence of this disease in China is low, and the clinical manifestations have great differences. The main symptoms are respiratory symptoms. Some children have gastrointestinal symptoms and/or PBS, and some children only show a single systemic lesion.

Outcome and prognostic factors after lung transplantation for bronchiectasis other than cystic fibrosis

BACKGROUND

While lung transplant (LTX) can be an effective therapy to provide the survival benefit in selected populations, post-transplant outcome in LTX recipients with bronchiectasis other than cystic fibrosis (CF) has been less studied. Pseudomonas aeruginosa, often associated with exacerbations in bronchiectasis, is the most common micro-organism isolated from LTX recipients. We aimed to see the outcomes of patients with bronchiectasis other than CF after LTX and seek the risk factors associated with pre- and post-transplant Pseudomonas status.

METHODS

Patients who underwent LTX at Tohoku University Hospital between January 2000 and December 2020 were consecutively included into the retrospective cohort study. Pre- and post-transplant prevalence of Pseudomonas colonization between bronchiectasis and other diseases was reviewed. Post-transplant outcomes (mortality and the development of chronic lung allograft dysfunction (CLAD)) were assessed using a Cox proportional hazards and time-to-event outcomes were estimated using the Kaplan-Meier method.

RESULTS

LTX recipients with bronchiectasis experienced a high rate of pre- and post-transplant Pseudomonas colonization compared to other diseases with statistical significance (p < 0.001 and p < 0.001, respectively). Nevertheless, long-term survival in bronchiectasis was as great as non-bronchiectasis (Log-rank p = 0.522), and the bronchiectasis was not a trigger for death (HR 1.62, 95% CI 0.63-4.19). On the other hand, the chance of CLAD onset in bronchiectasis was comparable to non-bronchiectasis (Log-rank p = 0.221), and bronchiectasis was not a predictor of the development of CLAD (HR 1.88, 95% CI 0.65-5.40).

CONCLUSIONS

Despite high prevalence of pre- and post-transplant Pseudomonas colonization, the outcome in LTX recipients with bronchiectasis other than CF was comparable to those without bronchiectasis.

Genetic analysis in Japanese patients with osteogenesis imperfecta: Genotype and phenotype spectra in 96 probands

BACKGROUND

Osteogenesis imperfecta (OI) is a rare connective-tissue disorder characterized by bone fragility. Approximately 90% of all OI cases are caused by variants in COL1A1 or COL1A2. Additionally, IFITM5 variants are responsible for the unique OI type 5. We previously analyzed COL1A1/2 variants in 22 Japanese families with OI through denaturing high-performance liquid chromatography screening, but our detection rate was low (41%).

METHODS

To expand the genotype-phenotype correlations, we performed a genetic analysis of COL1A1/2 and IFITM5 in 96 non-consanguineous Japanese OI probands by Sanger sequencing.

RESULTS

Of these individuals, 54, 41, and 1 had type 1 (mild), type 2-4 (moderate-to-severe), and type 5 phenotypes, respectively. In the mild group, COL1A1 nonsense and splice-site variants were prevalent (n = 30 and 20, respectively), but there were also COL1A1 and COL1A2 triple-helical glycine substitutions (n = 2 and 1, respectively). In the moderate-to-severe group, although COL1A1 and COL1A2 glycine substitutions were common (n = 14 and 18, respectively), other variants were also detected. The single case of type 5 had the characteristic c.-14C>T variant in IFITM5.

CONCLUSION

These results increase our previous detection rate for COL1A1/2 variants to 99% and provide insight into the genotype-phenotype correlations in OI.

Acute recurrent and chronic pancreatitis in children

Acute recurrent pancreatitis (ARP) is defined as two distinct episodes of acute pancreatitis (AP), whereas chronic pancreatitis (CP) is caused by persistent inflammation of the pancreas. In children they are caused by genetic mutations, autoimmune pancreatitis, congenital pancreatic abnormalities, and other conditions. Acute recurrent pancreatitis is frequently a precursor to CP, and both are thought to be on the same disease continuum. In particular, genetic factors are associated with early progression of ARP to CP. The diagnosis of CP, as in AP, is based on clinical findings, biochemical tests, and imaging studies. Findings of exocrine pancreatic dysfunction are also important in the diagnosis of CP. A step-up strategy has become increasingly standard for the treatment of patients with CP. This strategy starts with endoscopic treatment, such as pancreatic sphincterotomy and stenting, and progresses to surgery should endoscopic therapy fail or prove technically impossible. Non-opioid (e.g. ibuprofen / naproxen) and opioid (e.g. oxycodone) forms of analgesia are widely used in pediatric patients with AP or CP, whereas pancreatic enzyme replacement therapy may be beneficial for patients with abdominal pain, steatorrhea, and malnutrition. Despite the disparity in the age of onset, pediatric CP patients display some similarities to adults in terms of disease progress. To reduce the risk of developing pancreatic exocrine inefficiency, diabetes and pancreatic cancer in the future, clinicians need to be aware of the current diagnostic approach and treatment methods for ARP and CP and refer them to a pediatric gastroenterologist in a timely manner.

Case Report: Japanese Siblings of Cystic Fibrosis With a Novel Large Heterozygous Deletion in the CFTR Gene

Cystic fibrosis (CF) is a rare disease in the Japanese. The most common CFTR variant in Japanese CF patients is a large heterozygous deletion that can easily avoid detection by standard gene sequencing methods. We herein report a novel large heterozygous deletion in the CFTR gene in Japanese siblings with CF. A genetic analysis was performed in two patients (9-year-old boy and 5-month-old girl) who were clinically diagnosed with CF because of the positive result for the rapid fecal pancreatic elastase antigen test and the elevation of the sweat chloride concentration. In addition to conventional polymerase chain reaction (PCR) and direct sequencing, multiplex ligation-dependent probe amplification (MLPA) was performed to check for a large deletion and duplication of the CFTR gene. Based on MLPA findings, the breakpoint of heterozygous deletion was identified by real-time quantitative PCR followed by the sequence of the amplified junction fragment. In MLPA, the numbers of the fragments corresponding to exons 1, 16, 17a, and 17b and 234 nt and 747 nt upstream from the translation initiation codon of exon 1 in the CFTR gene and exon 3 in the ASZ1 gene were reduced by almost half. The c.2908+1085_3367+260del7201 variant (exon 16-17b deletion) was identified in one allele. The other allele had a large 137,567-bp deletion from g.117,361,112 (ASZ1 3' flanking region) to g.117,498,678 (CFTR intron 1) on chromosome 7. Since the deletion variant lacked the entire promoter region of CFTR, CFTR mRNA would not be transcribed from the allele, indicating it to be a novel pathogenic variant causing CF. As large mutations are frequently detected in Japanese CF patients, MPLA can be useful when searching for variants.

A systematic review of the clinical and genetic characteristics of Chinese patients with cystic fibrosis

OBJECTIVES

To investigate and summarize the clinical and genetic characteristics of Chinese cystic fibrosis (CF) patients to improve clinicians' understanding and decrease the rates of misdiagnosis and missed diagnoses in China.

METHODS

The EMBASE, Cochrane Library, PubMed and SinoMed databases were searched for studies involving Chinese CF patients from January 1975 to August 2019.

RESULTS

In total, 113 Chinese patients, including 53 males and 60 females, were reported. Nineteen patients had a family history of CF. The median age at diagnosis was 8.7 years. Among Chinese CF patients, 70.8% had bronchiectasis, 9.7% had a hemoptysis history, 33.6% had clubbed fingers, 17.7% had allergic bronchopulmonary aspergillosis, and 29.2% had chronic diarrhea; the incidence of malnutrition was 52.2%. Five patients had jaundice, 26 patients had hepatomegaly, and 9 patients had meconium ileus in the neonatal period, and the incidence of liver cirrhosis was 5.3%. The predominant organism in airways was Pseudomonas aeruginosa, followed by Staphylococcus aureus. Seventy-nine patients underwent the sweat test, and all of them were positive, with an average chloride ion level of 122.2 mmol/L. Eighty-eight Chinese CF patients underwent genetic testing, and 74 CF transmembrane conductance regulator (CFTR) gene mutations were reported. The most common gene mutation was c.2909G→A. One Phe508del gene mutation was observed.

CONCLUSION

The common clinical manifestations and CFTR gene mutations in Chinese CF patients are different from those in Caucasian patients. The age at CF diagnosis in China is relatively old, suggesting that the CF incidence in China may be seriously underestimated.

The Changing Epidemiology of Cystic Fibrosis: Incidence, Survival and Impact of the CFTR Gene Discovery

Significant advances in the management of cystic fibrosis (CF) in recentdecades have dramatically changed the epidemiology and prognosis of this serious disease, which is no longer an exclusively pediatric disease. This paper aims to review the changes in the incidence and survival of CF and to assess the impact of the discovery of the responsible gene (the CFTR gene) on these changes. The incidence of CF appears to be decreasing in most countries andpatient survival, which can be monitored by various indicators, has improved substantially, with an estimated median age of survivalof approximately50 years today. Cloning of the CFTR gene 30 years ago and efforts to identify its many mutations have greatly improved the management of CF. Implementation of genetic screening policies hasenabled earlier diagnosis (via newborn screening), in addition to prevention within families or in the general population in some areas (via prenatal diagnosis, family testing or population carrier screening). In the past decade, in-depth knowledge of the molecular bases of CF has also enabled the emergenceof CFTR modulator therapies which have led to major clinical advances in the treatment of CF. All of these phenomena have contributed to changing the face of CF. The advent of targeted therapies has paved the way for precision medicine and is expected to further improve survival in the coming years.

Host immune response against environmental nontuberculous mycobacteria and the risk populations of nontuberculous mycobacterial lung disease

Nontuberculous mycobacterial lung disease (NTM-LD) prevalence has been increasing over the recent decades. Numerous host factors are associated with NTM-LD development, including susceptible phenotypes such as ciliary defect and lung structural change, pulmonary clearance defect with poor clearance of secretions, and immune suppression. Specifically, regarding the susceptible host phenotypes without clear pathogenesis, a slender body, pectus excavatum, and postmenopausal female status are common. Also, decreased host immunity to NTM, especially T helper 1 cell responses is frequently observed. Even so, the underlying mechanisms remain unclear and relevant large-scale studies are lacking. Infections due to host genetics associated defects are mostly untreatable but rare in Asia, particularly Taiwan. Nevertheless, some risks for NTM-LD are controllable over disease progression. We suggest that clinicians first manage host factors and deal with the controllable characteristics of NTM-LD, followed by optimizing anti-NTM treatment. Further researches focusing on NTM-LD pathogenesis, especially the host-NTM interaction may advance understanding the nature of the disease and develop efficient therapeutic regimens.

Cystic fibrosis-associated liver disease in children

As improvements in nutritional and pulmonary care increase the life expectancy of cystic fibrosis (CF) patients, CF-associated liver disease (CFLD) is emerging as a cause of mortality. CFLD is the third leading cause of death in CF patients. We performed a search on PubMed and Google Scholar for published articles on CFLD. We reviewed the articles found in the literature search and gave priority to recent publications and studies with larger sample sizes. The prevalence of CFLD in the CF population is around 23% with a range of 2-62% and that prevalence increases linearly with age from 3.7% at age 5 to 32.2% at age 30. CFLD can present clinically in various ways such as hepatomegaly, variceal hemorrhage, persistent elevation of liver enzymes, and micro-gallbladder. Due to the focal nature of fibrosis in majority cases of CFLD, liver biopsies are sparsely performed for diagnosis or the marker of liver fibrosis. Although the mechanism of CFLD development is still unknown, many potential factors are reported. Some mutations of CFTR such as having a homozygous F508del mutation has been reported to increase the risk of developing CFLD and its severity. Having the SERPINA1 Z allele, a history of pancreatic insufficiency, a history meconium ileus, CF-related diabetes, or being male increases the risk of developing CFLD. Environmental factors do not appear to have significant effect on modulating CFLD development. Ursodeoxycholic acid is commonly used to treat or prevent CFLD, but the efficacy of this treatment is questionable.

Long-Term Treatment Outcome of Progressive Mycobacterium Avium Complex Pulmonary Disease

BACKGROUND

Multidrug therapy is essential for preventing respiratory failure in patients with highly progressive Mycobacterium avium complex pulmonary disease (MAC-PD). However, the prognosis and long-term outcome following combination therapy is poorly understood.

METHODS

We retrospectively evaluated the clinical characteristics and long-term outcomes in patients with chemo-naïve progressive MAC-PD, hospitalized for first-line multidrug therapy.

RESULTS

Among 125 patients, 86 (68.8%) received standardized treatment (rifampicin, ethambutol, clarithromycin), 25 (20.0%) received a fluoroquinolone (FQ)-containing regimen, and 53 (42.4%) received aminoglycoside injection. The sputum conversion rate was 80.0%, and was independently associated with standardized treatment. The incidence of refractory disease (45.6%) was independently and negatively associated with standardized regimen and aminoglycoside use. Choice of an FQ-containing regimen was not associated with positive outcome. Clarithromycin resistance occurred in 16.8% and was independently associated with refractory disease. MAC-PD-associated death occurred in 3.3% of patients with non-cavitary nodular bronchiectasis (NB) and 21.3% with cavitary MAC-PD over a median follow-up period of 56.4 months. The rates of MAC-PD-associated death were comparable between cavitary-NB and fibrocavitary disease. Concurrent chronic pulmonary aspergillosis (CPA) occurred in 13 (17.3%) patients with cavitary MAC-PD, and age, diabetes mellitus, and CPA were independent risk factors for mortality.

CONCLUSIONS

Standardized intensive multidrug treatment reduces disease progression and persistence in progressive MAC-PD. Cavitary NB may differ from, rather than being just an advanced stage of, non-cavitary NB. The high incidence and significant mortality of CPA in cavitary MAC-PD highlight the need for early diagnosis and treatment.

Newborn Screening for CF across the Globe-Where Is It Worthwhile?

Newborn screening (NBS) for cystic fibrosis (CF) has been performed in many countries for as long as four decades and has transformed the routine method for diagnosing this genetic disease and improved the quality and quantity of life for people with this potentially fatal disorder. Each region has typically undertaken CF NBS after analysis of the advantages, costs, and challenges, particularly regarding the relationship of benefits to risks. The very fact that all regions that began screening for CF have continued their programs implies that public health and clinical leaders consider early diagnosis through screening to be worthwhile. Currently, many regions where CF NBS has not yet been introduced are considering options and in some situations negotiating with healthcare authorities as policy and economic factors are being debated. To consider the assigned question (where is it worthwhile?), we have completed a worldwide analysis of data and factors that should be considered when CF NBS is being contemplated. This article describes the lessons learned from the journey toward universal screening wherever CF is prevalent and an analytical framework for application in those undecided regions. In fact, the lessons learned provide insights about what is necessary to make CF NBS worthwhile.

Potentially lethal cystic fibrosis gene variant in the orangutan

A syndrome of chronic upper and lower airway disease leading to increased morbidity and mortality occurs primarily in captive orangutans. Similarities in symptoms to the inherited human respiratory disease, cystic fibrosis, led us to hypothesize that orangutan respiratory disease is a result of variants in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. We identified the nonsense variant, c.484A>T (p.Lys162X), in heterozygosity in an unaffected orangutan. Analysis of the pedigree of this orangutan confirmed that both his sire and deceased fetus also harbored the c.484A>T allele. An expression minigene harboring c.484A>T produced no full-length CFTR protein in HEK293 cells. Finally, the c.484A>T CFTR messenger RNA abundance was severely reduced in primary nasal epithelial cells of the orangutan indicating that c.484A>T (p.Lys162X) is potentially lethal. Genetic screening of the captive orangutan population could be used to prevent transmission of this potentially lethal variant, and thus aid in the conservation of this critically endangered species.

Primary ciliary dyskinesia caused by a large homozygous deletion including exons 1-4 of DRC1 in Japanese patients with recurrent sinopulmonary infection

BACKGROUND

Diffuse panbronchiolitis (DPB) is a sinopulmonary disease mainly affecting Asian populations. Primary ciliary dyskinesia (PCD) is a genetically heterogeneous disorder impairing ciliary structure and function. These two disorders are not easily distinguished by clinical signs and symptoms.

METHODS

In 105 Japanese patients with recurrent sinopulmonary infection, initially diagnosed with DPB, and 37 patients with recurrent airway infection diagnosed in adulthood, the deletion allele of DRC1 or CCDC164, recently recognized as a pathogenic PCD gene variant, was searched using a multiplexed PCR-based method, and the deletion breakpoints and other variants around the gene were determined by Sanger sequencing and targeted resequencing.

RESULTS

A large homozygous deletion in DRC1 was identified in three of the 142 patients. Furthermore, heterozygous carriers of the deletion with the same breakpoint were found with the allele frequency of 0.002 in the healthy Japanese population, indicating that this loss-of-function variant may be acting as a common mutation causing PCD in Japanese.

CONCLUSION

PCD caused by the DRC1 defect is not readily identified by either high-speed video-microscopy or ciliary ultrastructure analysis, posing significant difficulties in reaching a correct diagnosis without the aid of genetic tests. Careful investigation of the causes of sinopulmonary diseases is warranted in Asian populations.

Primary ciliary dyskinesia in Japan: systematic review and meta-analysis

BACKGROUND

Primary ciliary dyskinesia (PCD) is a rare genetic disorder. Although the genetic tests and new diagnostic algorithms have recently been recommended, clinical signs and electron microscope (EM) findings have historically been the mainstays of diagnosis in Asia. To characterize PCD previously reported in Japan, we conducted a systematic review and meta-analysis.

METHODS

A search using MEDLINE, EMBASE, and Japana Centra Revuo Medicina (in Japanese) databases was carried out to identify articles reporting PCD, Kartagener syndrome, or immotile cilia syndrome in Japanese patients and published between 1985 and 2015.

RESULTS

After excluding duplication from 334 reports, we extracted 316 patients according to the criteria. Diagnosis was most frequently made in adulthood (148 patients [46.8%] ≥ 18 years old, 24 patients [7.6%] < 1 year old, 68 patients [21.5%] 1-17 years old and 76 patients [24.1%] lacking information). Of the 230 patients (72.8%) who received EM examination, there were patients with inner dynein arm (IDA) defects (n = 55; 23.9%), outer dynein arm (ODA) defects (14; 6.1%), both ODA and IDA defects (57; 24.8%), other structural abnormalities (25; 10.9%), no abnormalities (4; 1.7%), and no detailed conclusion or description (75; 32.6%).

CONCLUSION

Delayed diagnosis of this congenital disease with high frequency of IDA defects and low frequency of ODA defects appear to be historical features of PCD reported in Japan, when EM was a main diagnostic tool. This review highlights problems experienced in this field, and provides basic information to establish a modernized PCD diagnosis and management system in the future.

The Incidence of Cystic Fibrosis in the Central Region of Anatolia in Turkey Between 2015 and 2016

Background

Cystic fibrosis is the most common metabolic chronic disease among European Caucasian children. Cystic fibrosis incidence in Northern Europeans countries is approximately 1 in 3000 births while the worldwide prevalence varies considerably.

Aims

To determine the incidence of cystic fibrosis in the central region of Anatolia in Turkey using the newborn screening program data.

Study Design

Cross-sectional study

Methods

We used the records of the newborn screening program which is implemented by the Konya and Kayseri Provincial Health Directories. Between January 2015 and December 2016, there were a total of 119006 live births in Konya and Kayseri. The newborn screening test was applied to all these babies.

Results

During this period, there were 22 live born babies diagnosed with cystic fibrosis in Konya with an incidence of 2.9 per 10000 live births and 13 live born babies diagnosed with cystic fibrosis in Kayseri with an incidence of 2.8 per 10000 live births. In genetic of 30 patients, fifteen patients were homozygous, and 15 patients were a compound heterozygote. Twenty-one different gene variants were detected and the most common mutation was F508del (17/30).

Conclusion

We found the incidence of cystic fibrosis in central Anatolia similar to northern European countries.

The CFTR gene variants in Japanese children with idiopathic pancreatitis

The cystic fibrosis transmembrane conductance regulator (CFTR) gene has been reported as one of the pancreatitis susceptibility genes. Although many variants of CFTR have been reported in Caucasian patients, there are few data in Japanese patients. We aimed to survey CFTR variants in Japanese children with idiopathic pancreatitis. Twenty-eight Japanese paediatric patients with idiopathic pancreatitis were enroled, who were not previously diagnosed by genetic analysis of PRSS1 and SPINK1. The entire CFTR gene was sequenced in the patients by combining LA-PCR and next-generation sequencing analysis. To determine a splice-affecting variant, CFTR expression was investigated in the nasal epithelial cells by RT-PCR. One (3.6%) and 15 (53.6%) of 28 patients had pathogenic and functionally affected variants in the CFTR gene, respectively. Two variants, p.Arg352Gln and p.Arg1453Trp, were found more frequently in the patients compared with one in Japanese healthy controls (p = 0.0078 and 0.044, respectively). We confirmed skipping of exon 10 in the nasal epithelial cells in one patient having a splice-affecting variant (c.1210-12 T(5)) in intron 9. Functionally affected variants of the CFTR gene are not so rare in Japanese paediatric patients with idiopathic pancreatitis. Surveying CFTR gene variants in a Japanese sample could help identify pancreatitis risk in these children.

Mutations in a cystic fibrosis-related gene could help identify Japanese children at risk of developing pancreatic inflammation. Tadashi Kaname, of Tokyo’s National Center for Child Health and Development, and colleagues sequenced the cystic fibrosis transmembrane conductance regulator gene (CFTR) in 28 Japanese children with pancreatitis of unknown origin. The gene is involved in the development of cystic fibrosis and has been reported to be associated with pancreatitis but little is known about its role in idiopathic pancreatitis in Asian populations. The team found CFTR gene mutations in 16 out of the 28 children. Cystic fibrosis is uncommon among Japanese, so CFTR mutations were also thought to be rare. The study suggests, however, that mutations might not be so rare in Japanese children with idiopathic pancreatitis and could help identify those at risk of developing the condition.

Estimating carrier frequencies of newborn screening disorders using a whole-genome reference panel of 3552 Japanese individuals

Incidence rates of Mendelian diseases vary among ethnic groups, and frequencies of variant types of causative genes also vary among human populations. In this study, we examined to what extent we can predict population frequencies of recessive disorders from genomic data, and explored better strategies for variant interpretation and classification. We used a whole-genome reference panel from 3552 general Japanese individuals constructed by the Tohoku Medical Megabank Organization (ToMMo). Focusing on 32 genes for 17 congenital metabolic disorders included in newborn screening (NBS) in Japan, we identified reported and predicted pathogenic variants through variant annotation, interpretation, and multiple ways of classifications. The estimated carrier frequencies were compared with those from the Japanese NBS data based on 1,949,987 newborns from a previous study. The estimated carrier frequency based on genomic data with a recent guideline of variant interpretation for the PAH gene, in which defects cause hyperphenylalaninemia (HPA) and phenylketonuria (PKU), provided a closer estimate to that by the observed incidence than the other methods. In contrast, the estimated carrier frequencies for SLC25A13, which causes citrin deficiency, were much higher compared with the incidence rate. The results varied greatly among the 11 NBS diseases with single responsible genes; the possible reasons for departures from the carrier frequencies by reported incidence rates were discussed. Of note, (1) the number of pathogenic variants increases by including additional lines of evidence, (2) common variants with mild effects also contribute to the actual frequency of patients, and (3) penetrance of each variant remains unclear.

Characterization of Δ(G970-T1122)-CFTR, the most frequent CFTR mutant identified in Japanese cystic fibrosis patients

A massive deletion over three exons 16-17b in the CFTR gene was identified in Japanese CF patients with the highest frequency (about 70% of Japanese CF patients definitely diagnosed). This pathogenic mutation results in a deletion of 153 amino acids from glycine at position 970 (G970) to threonine at 1122 (T1122) in the CFTR protein without a frameshift. We name it Δ(G970-T1122)-CFTR. In the present study, we characterized the Δ(G970-T1122)-CFTR expressed in CHO cells using immunoblots and a super resolution microscopy. Δ(G970-T1122)-CFTR proteins were synthesized and core-glycosylated but not complex-glycosylated. This observation suggests that the Δ(G970-T1122) mutation can be categorized into the class II mutation like ΔF508. However, VX-809 a CFTR corrector that can help maturation of ΔF508, had no effect on Δ(G970-T1122). Interestingly C-terminal FLAG tag seems to partially rescue the trafficking defect of Δ(G970-T1122)-CFTR; however the rescued Δ(G970-T1122)-CFTR proteins do not assume channel function. Japanese, and perhaps people in other Asian nations, carry a class II mutation Δ(G970-T1122) with a higher frequency than previously appreciated. Further study of the Δ(G970-T1122)-CFTR is essential for understanding CF and CFTR-related diseases particularly in Asian countries.

Clinical and genetic characteristics of cystic fibrosis in CHINESE patients: a systemic review of reported cases

Cystic fibrosis (CF) is a rare disease most commonly seen in Caucasians. Only a few Chinese CF patients have been described in literature, taking into account the large population of China. In this systematic review, we collected the clinical and genetic information of 71 Chinese CF patients based on all available data. Compared with Caucasians, Chinese CF patients often present atypical symptoms, mainly displaying symptoms of pulmonary infection with fewer digestive symptoms. An ethnicity-specific CFTR variant spectrum was also observed in CF patients of Chinese origin, with p.Gly970Asp as the most common mutation while p.Phe508del, the most common pathogenic mutation in CF patients of Caucasian origin, is rare, suggesting the necessity of a Chinese-specific CFTR variant screening panel. Besides, multiplex ligation-dependent probe amplification analysis should be routinely considered, especially for those with unidentified mutations. Potential under-diagnosis of CF in Chinese patients might be caused by a combination of atypical clinical features and genetic heterogeneity in Chinese CF patients, the inaccessibility of sweat and genetic testing facilities, and the one-child policy in China. With the approval of promising small molecule correctors and potentiators, molecular characterization of Chinese-specific CFTR mutations will help to realize more precise treatment for Chinese CF patients.

Epidemiology of Rare Lung Diseases: The Challenges and Opportunities to Improve Research and Knowledge

Rare lung diseases encompass a broad spectrum of conditions and affect an estimated 1.2-2.5 million people in North America and 1.5-3 million people in Europe. While individual rare lung diseases affect less than 1 in 2000 individuals, collectively they have a significant impact upon the population at large. Hence it is vital to understand firstly the epidemiology and subsequently the pathogenesis and clinical course of these disorders. Through a greater understanding of these aspects of disease, progress can be made in reducing symptoms, containing healthcare costs and utilizing resources efficiently. Furthermore, a greater understanding of the pathobiology of rare lung diseases can inform both the pathogenesis and management of more common pulmonary disorders.In this chapter we review how epidemiological approaches and the utilization of patient registries has improved the knowledge and management of rare lung diseases. We further focus on the epidemiology of several of the more widely known rare pulmonary disorders, including idiopathic pulmonary fibrosis (IPF), cystic fibrosis (CF) and alpha-1 antitrypsin deficiency (AATD). To conclude we describe how patient advocacy groups and foundations have driven advances in research and management of ultra-rare lung diseases, namely, the major strides made in the management and understanding of lymphangioleiomyomatosis (LAM) and pulmonary alveolar proteinosis (PAP).We conclude that the models used to study some of the rarest of diseases may be successfully adopted by other rare and common disease communities, leading to improved care and the possibility of novel therapeutic options.

Achromobacter Infection Is Rare in Japanese Patients with Pulmonary B-cell Lymphoma

Objective Achromobacter xylosoxidans (A. xylosoxidans) has been recently reported to have an association with the development of pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma in patients from European countries. However, the prevalence rates for A. xylosoxidans may vary significantly from country to country. To assess this association, the prevalence of A. xylosoxidans was analyzed in Japanese patients with pulmonary B-cell lymphoma. Methods DNA samples were obtained from formalin-fixed, paraffin-embedded sections of pulmonary MALT lymphomas (n=52), diffuse large B-cell lymphomas (DLBCLs, n=18), and benign pulmonary lesions (n=19). All samples were histopathologically reviewed by experienced hematopathologists, and the clonality of all MALT lymphoma cases was confirmed by a polymerase chain reaction (PCR)-based IGH rearrangement clonality assay. They were also tested for the API2-MALT1 fusion transcript. The presence of bacterial DNA was assessed with a nested PCR, and DNA sequencing was performed to confirm the PCR specificity. Results A. xylosoxidans DNA was detected in 1/52 cases of pulmonary MALT lymphoma, 2/18 cases of DLBCL, and 0/19 cases of benign pulmonary lesions. The prevalence of A. xylosoxidans in pulmonary lymphoma was not significantly higher than in benign lesions. Conclusion The present study shows that A. xylosoxidans infection may not be associated with pulmonary B-cell lymphoma in a Japanese case series. Large-scale international studies are needed to clarify the role of A. xylosoxidans in pulmonary lymphoma.

Clinical characterization and diagnosis of cystic fibrosis through exome sequencing in Chinese infants with Bartter-syndrome-like hypokalemia alkalosis

Cystic fibrosis (CF) is a fatal autosomal-recessive disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. CF is characterized by recurrent pulmonary infection with obstructive pulmonary disease. CF is common in the Caucasian population but is rare in the Chinese population. The symptoms of early-stage CF are often untypical and may sometimes manifest as Bartter syndrome (BS)-like hypokalemic alkalosis. Therefore, the ability of doctors to differentiate CF from BS-like hypokalemic alkalosis in Chinese infants is a great challenge in the timely and accurate diagnosis of CF. In China, sporadic CF has not been diagnosed in children younger than three years of age to date. Three infants, who were initially admitted to our hospital over the period of June 2013 to September 2014 with BS-like hypokalemic alkalosis, were diagnosed with CF through exome sequencing and sweat chloride measurement. The compound heterozygous mutations of the CFTR gene were detected in two infants, and a homozygous missense mutation was found in one infant. Among the six identified mutations, two are novel point mutations (c.1526G > C and c.3062C > T) that are possibly pathogenic. The three infants are the youngest Chinese patients to have been diagnosed with sporadic CF at a very early stage. Follow-up examination showed that all of the cases remained symptom-free after early intervention, indicating the potential benefit of very early diagnosis and timely intervention in children with CF. Our results demonstrate the necessity of distinguishing CF from BS in Chinese infants with hypokalemic alkalosis and the significant diagnostic value of powerful exome sequencing for rare genetic diseases. Furthermore, our findings expand the CFTR mutation spectrum associated with CF.

Diagnosis of cystic fibrosis in an adult Japanese male

Chest computed tomography image of a 23‐year‐old man. Image shows right‐sided middle and lower lobe consolidation and multiple cystic bronchiectasis.

The First Successful Lung Transplantation in a Korean Child with Cystic Fibrosis

Cystic fibrosis (CF) is an autosomal recessive inherited multisystem disorder caused by mutations of the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein. Respiratory failure remains the most frequent cause of morbidity and mortality. Lung transplantation is the only option to treat end-stage lung disease. Very few cases of CF occur in Koreans. We report the case of a 12-year-old girl with respiratory failure due to CF who underwent lung transplantation. She had been diagnosed with CF 8 years previously after being treated for recurrent Pseudomonas aeruginosa pneumonia and malnutrition based on sweat chloride concentrations and the CFTR protein gene mutation test. Progression to end-stage lung disease and respiratory failure led to registration with the Korean Network for Organ Sharing. She underwent successful double lung transplantation in 2014. Although she has diabetes mellitus and chronic kidney disease, she has a better quality of life and a prolonged life expectancy.

Monogenic diseases in respiratory medicine: Clinical perspectives

With the increasing awareness of genetics in respiratory medicine and improvements in molecular diagnostic techniques, many complicated and rare diseases in respiratory medicine can be diagnosed. Most respiratory diseases have no specific phenotype. However, the clinical spectrum of monogenic diseases in respiratory medicine varies, from pulmonary disease to other inherited disorders that involve the lung. The genes that mediate some of these diseases have been identified. Certain monogenic diseases remain poorly characterized clinically. Because of the specificity of the phenotype of respiratory disease, a future challenge will be to correlate the phenotype and genotype and understand its phenotypic variability. With the development of precision medicine, research on monogenic disorders has been intensive and vigorous. In this article, we provide a brief clinical introduction to monogenic diseases in pediatrics.

Four case reports of Chinese cystic fibrosis patients and literature review

AIM

Cystic fibrosis (CF) is an extremely rare disease in Asians. Here, we report four Chinese children with CF and review the literature about Chinese CF patients.

METHODS

The cystic fibrosis transmembrane conductance regulator (CFTR) gene testing was performed on four suspected patients for CF screening. We also reviewed the literature about Chinese CF patients from 1970s. The clinical data of all these CF patients were summarized.

RESULTS

We diagnosed four CF patients who had mutations in the CFTR gene. We identified six different mutations in the four patients. The c.1766+5G>T, c.595C>T, c.2909G>A, and c.4056G>C had been reported already. The two splicing mutations of c.579+1_579+2insACAT and c.1117-1G>C were novel mutations. There have been 46 Chinese CF patients reported in literature from 1974 up to present (2016.12). The clinical manifestations of CF involved several systems. The most common symptom was recurrent pulmonary infections. Thirty-three different mutations were identified; c.1766 + 5G>T was the most common mutation among Chinese CF patients. Only one of these mutations (R553X) was in the Caucasian CF screening panel. The spectrum of CFTR mutations in Chinese was highly different from that of Caucasian.

CONCLUSIONS

There was a high risk of misdiagnosis or delayed diagnosis of CF even in suspected cases in China. It is necessary to educate Chinese clinicians about the signs, symptoms, and diagnosis of cystic fibrosis and promote the implementation of the sweat chloride test.

Chest CT Features of Cystic Fibrosis in Korea: Comparison with Non-Cystic Fibrosis Diseases

OBJECTIVE

Cystic fibrosis (CF) is a rare congenital disease in Korea, and its clinical and imaging findings are unclear. The objective of our study was to describe the clinical and CT features of CF in Korea and compare its features with those of other diseases mimicking CF.

MATERIALS AND METHODS

From November 1994 to December 2014, a presumptive diagnosis of CF was made in 23 patients based on clinical or radiological examination. After the exclusion of 10 patients without diagnostic confirmation, 13 patients were included in the study. A diagnosis of CF was made with the CF gene study. CT findings were evaluated for the presence and distribution of parenchymal abnormalities including bronchiectasis, tree-in-bud (TIB) pattern, mucus plugging, consolidation, and mosaic attenuation.

RESULTS

Of the 13 patients, 7 (median age, 15 years) were confirmed as CF, 4 (median age, 19 years) had primary ciliary dyskinesia, 1 had bronchiectasis of unknown cause, and 1 had chronic asthma. CT of patients with CF showed bilateral bronchiectasis, TIB pattern, mosaic attenuation, and mucus plugging in all patients, with upper lung predominance (57%). In CT of the non-CF patients, bilateral bronchiectasis, TIB pattern, mosaic attenuation, and mucus plugging were also predominant features, with lower lung predominance (50%).

CONCLUSION

Korean patients with CF showed bilateral bronchiectasis, cellular bronchiolitis, mucus plugging, and mosaic attenuation, which overlapped with those of non-CF patients. CF gene study is recommended for the definitive diagnosis of CF in patients with these clinical and imaging features.

CFTR founder mutation causes protein trafficking defects in Chinese patients with cystic fibrosis

Background

Cystic fibrosis (CF) is a rare condition in Asians. Since 1985, only about 30 Chinese patients have been reported with molecular confirmation.

Method

Using our in‐house next‐generation sequencing (NGS) pipeline for childhood bronchiectasis, we identified disease‐causing CFTR mutations in CF patients in Hong Kong. After identifying p.I1023R in multiple patients, haplotype analysis was performed with genome‐wide microarray to ascertain the likelihood of this being a founder mutation. We also assessed the processing and gating activity of the mutant protein by Western hybridization and patch‐clamp test.

Results

Molecular diagnoses were confirmed in four patients, three of whom shared a missense mutation: CFTR:c.3068T>G:p.I1023R. The results suggested that p.I1023R is a founder mutation in southern Han Chinese. In addition, the processing and gating activity of the mutant protein was assessed by gel electrophoresis and a patch‐clamp test. The mutant protein exhibited trafficking defects, suggesting that the dysfunction is caused by reduced cell surface expression of the fully glycosylated proteins.

Conclusion

Together with other previously reported mutations, the specific founder mutation presented herein suggests a unique CFTR mutation spectrum in the southern Chinese populations, and this finding has vital implications for improving molecular testing and mutation‐specific treatments for Chinese patients with CF.

Genetic Analysis of Japanese Children With Acute Recurrent and Chronic Pancreatitis

OBJECTIVES

Causes of acute recurrent pancreatitis (ARP) or chronic pancreatitis (CP) are sometimes difficult to determine in children. In such patients, genetic analysis may prove helpful. The present study analyzed mutations of cationic trypsinogen (PRSS1), serine protease inhibitor Kazal type 1 (SPINK1), chymotrypsin C (CTRC), and carboxypeptidase A1 (CPA1) and investigated the clinical features of children with these mutations.

METHODS

Genetic analyses of mutations in these 4 genes were conducted in 128 patients with ARP or CP. Characteristics of the patients showing mutations were investigated using medical records.

RESULTS

Fifty of the 128 (39.1%) subjects had at least 1 mutation (median age at onset, 7.6 years). Abdominal pain was the presenting symptom of pancreatitis in 48 of the 50 patients (96%). Fifteen of those 50 patients (30.0%) had a family history of pancreatitis. Gene mutations were present in PRSS1 in 26 patients, SPINK1 in 23, CTRC in 3, and CPA1 in 5. In the 31 patients with mutations in SPINK1, CTRC, or CPA1, 16 (51.6%) had homozygous or heterozygous mutations with other mutations. Three patients underwent surgery and another 4 patients underwent endoscopy to manage ARP or CP. Although 3 of the 7 patients complained of mild abdominal pain, none of those 7 patients experienced any obvious episode of ARP after treatment.

CONCLUSIONS

In pediatric patients with idiopathic ARP and CP, genetic analysis is useful for identifying the cause of pancreatitis. Early endoscopic or surgical treatment prevents ARP by extending the interval between episodes of pancreatitis in this population.

Pneumococcal vaccines for cystic fibrosis

BACKGROUND

Invasive pneumococcal disease is associated with significant mortality and many countries have introduced routine pneumococcal vaccination into their childhood immunisation programmes. Whilst pneumococcal disease in cystic fibrosis is uncommon, pneumococcal immunisation may offer some protection against pulmonary exacerbations caused by this pathogen. In the USA and UK pneumococcal vaccination is currently recommended for all children and adults with cystic fibrosis. This is an update of a previously published review.

OBJECTIVES

To assess the efficacy of pneumococcal vaccines in reducing morbidity in people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Cystic Fibrosis Trials Register, which comprises references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. In addition, the pharmaceutical manufacturers of the polysaccharide and conjugate pneumococcal vaccines were approached.Date of the most recent search: 27 June 2016.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing pneumococcal vaccination (with either a polysaccharide or conjugate pneumococcal vaccine) with non-vaccination or placebo in children or adults with cystic fibrosis were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

No relevant trials were identified.

MAIN RESULTS

There are no trials included in this review.

AUTHORS' CONCLUSIONS

As no trials were identified we cannot draw conclusions on the efficacy of routine pneumococcal immunisation in people with cystic fibrosis in reducing their morbidity or mortality. As many countries now include pneumococcal immunisation in their routine childhood vaccination schedule it is unlikely that future randomised controlled trials will be initiated. Rigorously conducted epidemiological studies may offer the opportunity to evaluate the efficacy of pneumococcal vaccination in reducing morbidity and mortality in people with cystic fibrosis.