Investigation of age and smoking in NSCLC patients with uncommon EGFR mutations.

Introduction: In addition to the two common epidermal growth factor receptor (EGFR) mutations, there are many uncommon mutations. Due to the high number of uncommon types, as well as the rarity of patients, there is lack of information regarding patient demographics, especially age distribution and smoking status. Against this background, we conducted an analysis to clarify the background of patients with uncommon EGFR mutations, especially considering their age distribution and smoking status. Materials and Methods: We retrospectively reviewed the medical records of non-small cell lung cancer (NSCLC) patients diagnosed in a multicenter clinical practice from 2002 to 2023. Patients included all cases of non-advanced and advanced NSCLC with uncommon EGFR mutations. Result: Information on 158 patients with uncommon EGFR mutation was collected. Median age was 72 years, with the age distribution showing that most patients were in their 70s. There was a significant difference between the proportion of patients aged up to 59 years and the proportion aged 75 years or older. In 88 patients with a smoking habit history, a significant correlation was found between smoking index and age. Among non-smokers, there was a peak between ages 70 and 74, which was older than the peak among smokers. Conclusions: Even in elderly patients and NSCLC patients with a history of smoking, although it is unclear whether EGFR mutation is common or uncommon, EGFR gene testing should be performed considering the possibility of these patients being EGFR-positive.

Patient Age and EGFR-positive Non-small Cell Lung Cancer: A Multicenter Retrospective Study.

BACKGROUND/AIM: The median age of subjects in many clinical trials of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor conducted to date has been approximately 60 years. However, it is not uncommon to encounter EGFR gene-positive patients in their 70s or 80s. Based on information obtained from these clinical trials, EGFR gene-positive non-small cell lung cancer (NSCLC) patients are considered to be younger than EGFR-negative patients. In this study, we analyzed clinical data to identify whether this assumption is true. PATIENTS AND METHODS: We retrospectively reviewed the medical records of NSCLC patients diagnosed in a multicenter clinical practice from 2009 to 2023. Patients included all cases of non-advanced and advanced NSCLC. RESULTS: Information on 2,540 patients, including 605 EGFR gene-positive patients, was collected. The median age of EGFR-positive and EGFR-negative patients was 72 years and 71 years, respectively, and there was no significant difference in the age of patients between these two groups (p=0.7887). The most common age in these two groups was 70 years. Among the EGFR gene subtypes, the frequency of exon 19 deletion decreased with age, whereas that of EGFR L858R increased. CONCLUSION: Patients in their 70s and 80s with non-small cell lung cancer were relatively frequently EGFR gene-positive. To avoid missing out on treatment opportunities, EGFR gene testing should also be performed on patients in this age group.

The primary ciliary dyskinesia-related genetic risk score is associated with susceptibility to adult-onset asthma.

BACKGROUND: Disturbance of mucociliary clearance is an important factor in the pathogenesis of asthma. We hypothesized that common variants in genes responsible for ciliary function may contribute to the development of asthma with certain phenotypes. METHODS: Three independent adult Japanese populations (including a total of 1,158 patients with asthma and 2,203 non-asthmatic healthy participants) were studied. First, based on the ClinVar database (https://www.ncbi.nlm.nih.gov/clinvar/), we selected 12 common single-nucleotide polymorphisms (SNPs) with molecular consequences (missense, nonsense, and 3'-untranslated region mutation) in 5 primary ciliary dyskinesia (PCD)-related genes and calculated a PCD-genetic risk score (GRS) as a cumulative effect of these PCD-related genes. Second, we performed a two-step cluster analysis using 3 variables, including PCD-GRS, forced expiratory volume in 1 second (%predicted FEV1), and age of asthma onset. RESULTS: Compared to adult asthma clusters with an average PCD-GRS, clusters with high and low PCD-GRS had similar overall characteristics: adult-onset, female predominance, preserved lung function, and fewer features of type 2 immunity as determined by IgE reactivity and blood eosinophil counts. The allele frequency of rs1530496, a SNP representing an expression quantitative trait locus (eQTL) of DNAH5 in the lung, showed the largest statistically significant difference between the PCD-GRS-High and PCD-GRS-Low asthma clusters (p = 1.4 x 10-15). CONCLUSION: Genes associated with PCD, particularly the common SNPs associated with abnormal expression of DNAH5, may have a certain influence on the development of adult-onset asthma, perhaps through impaired mucociliary clearance.

A solitary rod-shaped intertrabecular metastasis in the femur.

Intertrabecular metastasis (ITM) is a type of bone metastasis characterized by tumour growth without significant trabecular changes. ITM is most commonly found in vertebral bodies, and rarely in long bones. We report a solitary rod-shaped ITM of lung adenocarcinoma in the femur.

Giant bullous emphysema successfully treated with percutaneous drainage followed by resection: A case complicated by lung cancer diagnosed by intraoperative biopsy.

We present a case of bilateral giant bullous emphysema (GBE) with rapidly progressive dyspnea. The dyspnea was thought to be due to tension bullae caused by the check valve mechanism in COVID-19 bronchitis. Multiple nodules were also detected on both sides of the lung. As the patient had poor pulmonary reserve for surgical bullectomy, we first performed percutaneous intracavitary drainage. Prior to this procedure, we placed a chest tube in the thoracic cavity to avoid tension pneumothorax. As a result, the patient's remaining lung expanded and respiratory status improved, allowing him to undergo surgical bullectomy. Intraoperatively, needle biopsy of the lung nodule was directly performed, which led to a diagnosis of adenocarcinoma. Despite multiple distant metastases, the patient's general condition improved postoperatively, and chemotherapy was successfully initiated.

The Macklin effect in tension pneumomediastinum in a patient with interstitial pneumonia.

Tension pneumomediastinum is a rare complication of interstitial pneumonia. This case shows computed tomography findings of the Macklin effect, in which air dissection along the bronchovascular interstitium caused by alveolar rupture leads to pneumomediastinum.

Early chronic obstructive pulmonary disease: Associations of two spirometry criteria with clinical features.

BACKGROUND: Two spirometry criteria have been proposed for early chronic obstructive pulmonary disease (COPD) in young smokers: 1) forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) < the lower limit of normal (LLN), and 2) FEV1 decline ≥60 ml/year. These criteria have yet to be validated. This study explored clinical factors associated with these two spirometry criteria. METHODS: This retrospective study analysed medical check-up data from 13,010 consecutive subjects aged <50 years who underwent current and 3 previous spirometry tests in Japan. Current ≥10 pack-year smokers were the main focus of analysis; those meeting one or more spirometry criteria were diagnosed with early COPD. Early COPD was categorized into three subtypes: FEV1/FVC < LLN and FEV1 decline <60 ml/year (type 1), FEV1/FVC ≥ LLN and FEV1 decline ≥60 ml/year (type 2), and FEV1/FVC < LLN and FEV1 decline ≥60 ml/year (type 3). RESULTS: Of the 1579 current ≥ 10 pack-year smokers, 488 (30.9%) met the early COPD criteria. Multivariate multinomial logistic models adjusted for age, sex, height, body mass index (BMI) and smoking history indicated that past BMI increase and low exercise were associated with higher type 2 early COPD incidence (odds ratio (OR) [95% confidence interval (CI)] = 4.30 [3.10, 6.04], and 0.80 [0.69, 0.93], respectively) but not with higher type 1 incidence. A history of asthma was associated with higher type 3 incidence (OR [95% CI] = 1.98 [1.18, 3.07]). CONCLUSIONS: The 3 types of spirometry-based early COPD have different clinical factors. Their trajectories should be explored in longitudinal studies.

Common exacerbation-prone phenotypes across asthma and chronic obstructive pulmonary disease (COPD).

BACKGROUND AND OBJECTIVES: Chronic inflammatory airway diseases, including asthma and chronic obstructive pulmonary disease (COPD), are complex syndromes with diverse clinical symptoms due to multiple pathophysiological conditions. In this study, using common and shared risk factors for the exacerbation of asthma and COPD, we sought to clarify the exacerbation-prone phenotypes beyond disease labels, and to specifically investigate the role of the IL4RA gene polymorphism, which is related to type 2 inflammation, in these exacerbation-prone phenotypes. METHODS: The study population comprised patients with asthma (n = 117), asthma-COPD overlap (ACO; n = 37) or COPD (n = 48) and a history of exacerbation within the previous year. Cluster analyses were performed using factors associated with both asthma and COPD exacerbation. The association of the IL4RA gene polymorphism rs8832 with each exacerbation-prone phenotype was evaluated by multinomial logistic analyses using non-asthma non-COPD healthy adults as controls (n = 1,529). In addition, the genetic influence of rs8832 was also examined in asthma patients with allergic rhinitis and no history of exacerbation (n = 130). RESULTS: Two-step cluster analyses identified five clusters that did not necessarily correspond to the diagnostic disease labels. Cluster 1 was characterized by high eosinophil counts, cluster 2 was characterized by smokers with impaired lung function, cluster 3 was characterized by the presence of gastroesophageal reflux, cluster 4 was characterized by non-allergic females, and cluster 5 was characterized by allergic rhinitis and elevated total immunoglobulin E levels. A significant association with rs8832 was observed for cluster 5 (odds ratio, 3.88 (1.34-11.26), p = 0.013) and also for the type 2 exacerbation-prone phenotypes (clusters 1 and 5: odds ratio, 2.73 (1.45-5.15), p = 1.9 × 10-3). DISCUSSION: Our results indicated that the clinical heterogeneity of disease exacerbation may reflect the presence of common exacerbation-prone endotypes across asthma and COPD, and may support the use of the treatable traits approach for the prevention of exacerbations in patients with chronic inflammatory airway diseases.

A longitudinal comparison of college student mental health under the COVID-19 self-restraint policy in Japan.

BACKGROUND: The coronavirus-19 (COVID-19) pandemic has resulted in substantial mental health problems. In addition to the fear of infection, prevention policies that result in isolation such as lockdowns or, in Japan, "self-restraint," are associated with psychological symptoms. University students are vulnerable to emotional disorders because of the psychological challenges associated with the transition to adulthood. Therefore, we investigated changes in the mental health of university students before and during the COVID-19 pandemic. METHODS: We used data from depression screening conducted by the University of Tsukuba, Japan, during student health examinations. Students completed the Patient Health Questionnaire-9 (PHQ-9) and an open-ended question on stress self-coping. RESULTS: In 2020, 9.6% of students were depressed, approximately twice as many as in previous years. The paired samples Wilcoxon test showed that PHQ-9 scores were significantly higher in 2020 than in 2019; the largest effect size was for sleep difficulties. Analysis of the open-ended responses for stress coping strategies showed that physical activity and online communication were most frequently used. LIMITATIONS: The 2020 survey was web-based, whereas the surveys in previous years were completed in person. Only approximately one-sixth of participants answered the open-ended question. CONCLUSIONS: The percentage of students with mental health problems has doubled, and more attention to student mental health is needed. However, many students seem to be using appropriate coping measures. Education about best practices and raising awareness about establishing and maintaining sleep-wake rhythms may be useful.

Expression quantitative trait loci for ETV4 and MEOX1 are associated with adult asthma in Japanese populations.

ETS variant transcription factor 4 (ETV4) is a recently identified transcription factor that regulates gene expression-based biomarkers of asthma and IL6 production in an airway epithelial cell line. Given that ETV4 has not yet been implicated in asthma genetics, we performed genetic association studies of adult asthma in the ETV4 region using two independent Japanese cohorts (a total of 1532 controls and 783 cases). SNPs located between ETV4 and mesenchyme homeobox 1 (MEOX1) were significantly associated with adult asthma, including rs4792901 and rs2880540 (P = 5.63E-5 and 2.77E-5, respectively). The CC haplotype of these two SNPs was also significantly associated with adult asthma (P = 8.43E-7). Even when both SNPs were included in a logistic regression model, the association of either rs4792901 or rs2880540 remained significant (P = 0.013 or 0.007, respectively), suggesting that the two SNPs may have independent effects on the development of asthma. Both SNPs were expression quantitative trait loci, and the asthma risk alleles at both SNPs were correlated with increased levels of ETV4 mRNA expression. In addition, the asthma risk allele at rs4792901 was associated with increased serum IL6 levels (P = 0.041) in 651 healthy adults. Our findings imply that ETV4 is involved in the pathogenesis of asthma, possibly through the heightened production of IL6.

ORMDL3/GSDMB genotype as a risk factor for early-onset adult asthma is linked to total serum IgE levels but not to allergic sensitization.

BACKGROUND: An orosomucoid-like 3 (ORMDL3)/gasdermin B (GSDMB) gene locus on chromosome 17q is consistently associated with childhood-onset asthma, which is highly atopic. As some evidence suggests the relationship between asthma and allergic sensitization reflects asthma patient susceptibility to augmented IgE responses driven by common environmental allergens rather than an increased asthma risk after allergen exposure, we aimed to determine any relationships between this locus region and childhood-onset adult asthma with regard to serum total IgE levels or allergic sensitization. METHODS: We conducted a case-control association study using three independent Japanese populations (3869 total adults) and analyzed the ORs for association of rs7216389, an expression quantitative trait locus for ORMDL3/GSDMB, with adult asthma according to onset age. Additionally, associations between the rs7216389 genotype and total serum IgE levels or allergic sensitization was examined. RESULTS: Rs7216389 was associated with both childhood-onset adult asthma (OR for asthmatic patients afflicted at the age of 10 years or younger = 1.61, p = 0.00021) and asthmatic patients with higher levels of total serum IgE (OR for asthmatic patients with IgE ≥1000IU/mL = 1.55, p = 0.0033). In both healthy controls and in the combined healthy and asthmatic individuals, rs7216389 was correlated with increased total serum IgE levels (p < 0.0005), but not allergic sensitization (p > 0.1). CONCLUSIONS: ORMDL3/GSDMB is an important susceptibility gene for childhood-onset adult asthma in Japanese populations and this association is linked to elevated total serum IgE levels but not to allergic sensitization.

Genetic impact of CDHR3 on the adult onset of asthma and COPD.

BACKGROUND: Adult-onset asthma and chronic obstructive pulmonary disease (COPD) are heterogeneous diseases caused by complex gene-environment interactions. A functional single nucleotide polymorphism of cadherin-related family member 3 (CDHR3), known as a receptor of rhinovirus-C, is associated with childhood-onset asthma especially in atopic individuals. OBJECTIVE: Here, we identified risk factors for adult-onset asthma and COPD, focusing on the impact of the CDHR3 variant in atopic individuals. METHODS: We conducted a longitudinal, retrospective, observational cohort study of 1523 healthy adults with baseline examinations at Tsukuba Medical Center Hospital in 2008 and retrospectively identified new-onset, physician-diagnosed asthma or COPD from 2009 to 2018. We assessed risk factors by the Cox regression analysis. The impact of CDHR3 variant rs6967330 was also examined in individuals with pre-existing atopy. RESULTS: Over 10 study years, 103 people developed airway diseases (79 asthma and 24 COPD; 52 females, average onset-age 55 years old, range 38-80). Higher body mass index (BMI) and lower forced expiratory volume in one second/forced vital capacity (FEV1 /FVC) ratio were significant risk factors (BMI: HR 1.072 [95% CI 1.005-1.14], P = .034; FEV1 /FVC ratio: HR 1.091 [1.044-1.14], P = .00011). Restriction to atopic individuals saw the A allele at rs6967330 and lower FEV1 /FVC ratio to associate with adult-onset disease (A allele: HR 2.89 [1.57-5.20], P = .00062; FEV1 /FVC ratio: HR 1.10 [1.04-1.17], P = .0010). CONCLUSION AND CLINICAL RELEVANCE: Genetic susceptibility to rhinovirus-C infection in atopic individuals is a risk factor for chronic airway diseases even in later life.

Effects of Lung Function-Related Genes and TSLP on COPD Phenotypes.

A weighted genetic risk score (GRS) based on 16 SNPs implicated in reduced lung function in both Japanese and non-Japanese populations was previously associated with the onset of COPD and asthma. We here examine the genetic impact of this lung function GRS on specific COPD phenotypes. A cohort of Japanese COPD patients (N = 270) underwent lung function testing followed by genotyping with allele-specific arrays for 16 SNPs as well as expression quantitative trait loci at TSLP (rs2289276, rs3806933). Lung function GRS scoring and two-step cluster analyses grouped patients into different COPD phenotypes based on gender, age, smoking index, %FEV1 and lung function GRS. The genetic effect of TSLP on COPD phenotypes was also examined for interactions with the lung function GRS. A total of 270 participants were grouped into 5 clusters. The cluster with the highest levels of lung function GRS was characterized by moderate to severe airflow obstruction and the highest blood eosinophil counts. Regarding TSLP, an increased number of T alleles at both SNPs was found in the cluster characterized by moderate to severe airflow obstruction and heavy smoking (rs2289276, p value = 0.035; rs3806933, p value = 0.047) independent of the lung function GRS. A genetic susceptibility to impaired lung function carries an increased risk of developing COPD characterized by increased eosinophil counts and severe airflow obstruction while individuals with increased TSLP responses to external stimuli have an independent risk of developing severe airflow obstruction in the presence of heavy smoking.

The Concavity of the Maximal Expiratory Flow-Volume Curve Reflects the Extent of Emphysema in Obstructive Lung Diseases.

A concave-shaped maximal expiratory flow-volume (MEFV) curve is a spirometric feature in chronic obstructive pulmonary disease (COPD). The MEFV curve is characterized by an increase in the Obstructive Index, which is defined as a ratio of forced vital capacity to the volume-difference between two points of half of the peak expiratory flow on the MEFV curve. We hypothesized that the Obstructive Index would reflect the severity of emphysema in patients with COPD and asthma-COPD overlap (ACO). Thus, the aim of this retrospective study was to evaluate whether the Obstructive Index on spirometry is associated with the extent of emphysema on computed tomography (CT) in patients with COPD, ACO, and asthma (N = 65, 15, and 53, respectively). The percentage of low-attenuation volume (LAV%) and wall area (WA%) were measured on CT. The Obstructive Index was higher in patients with COPD and ACO than in those with asthma. Spearman correlation showed that a greater Obstructive Index was associated with a higher LAV%, but not WA%. Multivariate analysis showed that Obstructive Index was associated with LAV% (standardized ß = 0.43, P < 0.0001) independent of other spirometric indices. The Obstructive Index is a useful spirometric index that reflects the extent of emphysema.

A cis-eQTL allele regulating reduced expression of CHI3L1 is associated with late-onset adult asthma in Japanese cohorts.

BACKGROUND: The chitinase-like protein YKL-40 plays a major role in inhibiting the inflammasome. Deregulation of inflammasome activation is emerging as a key modulator of pathologic airway inflammation in patients with asthma. We determined whether cis-expression quantitative trait loci (eQTLs) of the gene that encodes YKL-40, chitinase 3-like 1 (CHI3L1), are involved in the onset of asthma or in specific asthma phenotypes. METHODS: This case-control study, which was conducted at the University of Tsukuba, Japan, included a total of 2709 adults from the Tsukuba genome-wide association study (GWAS) cohort (734 healthy volunteers and 237 asthma patients), the Tsukuba replication cohort (375 healthy adult volunteers and 381 adult asthma patients), and the Hokkaido replication cohort (554 healthy adult volunteers and 428 adult asthma patients). Among 34 cis-eQTLs in CHI3L1 in the lung, rs946261 was associated with adult asthma in these Japanese cohorts. The genetic impact of rs946261 on asthma was also examined according to the age at onset and adult asthma clusters. RESULTS: In the Tsukuba GWAS cohort, the C allele at rs946261 was significantly associated with reduced expression of CHI3L1 mRNA in the lung and with development of asthma (odds ratio (OR) 1.27; P = 0.036). The association was also observed following analysis of the three Japanese cohorts (OR 1.16; P = 0.013). A stronger association was found with late-onset asthma that developed at 41 years of age or later (OR 1.24; 95% confidence interval (CI) 1.07-1.45; P = 0.0058) and with a specific asthma phenotype characterized by late onset, less atopy, and mild airflow obstruction (OR 1.29; 95% CI 1.03-1.61; P = 0.027). CONCLUSIONS: The genotype consisting of the cis-eQTL allele that reduces expression of CHI3L1 was specifically associated with late-onset adult asthma. Given the important role of YKL-40 in many pathophysiological processes, including cell growth, migration, chemotaxis, reorganization, and tissue remodeling, it may be involved in an important pathogenic role in the establishment of inflammation and remodeling in asthmatic airways. Our findings may indicate the presence of a specific endotype related to exaggerated activation of YKL-40 in the pathogenesis of late-onset adult asthma.

Association analyses of eQTLs of the TYRO3 gene and allergic diseases in Japanese populations.

BACKGROUND: TYRO3 is a member of the TAM (TYRO3, AXL, MERTK) receptor tyrosine kinase family and functions to limit type 2 immune responses implicated in allergic sensitization. Recent studies have shown that multiple intronic variants of TYRO3 were associated with asthma, implying that genetic variation could contribute to errant immune activation. We therefore hypothesized that expression quantitative trait loci (eQTLs) of the TYRO3 gene influence the development of allergic diseases (including asthma and allergic rhinitis) in Japanese populations. METHODS: We performed a candidate gene case-control association study of 8 eQTLs of TYRO3 on atopy, asthma, and allergic rhinitis using 1168 unrelated Japanese adults who had GWAS genotyping. We then examined the genetic impact of rs2297377 (TYRO3) on atopy and allergic rhinitis in 2 other independent Japanese populations. RESULTS: A meta-analysis of 3 Japanese populations (a total of 2403 Japanese adults) revealed that rs2297377 was associated with atopy and allergic rhinitis (OR = 1.29 and 1.31; P = 0.00041 and 0.0010, respectively). The risk allele at rs2297377 correlated with decreased expression of TYRO3 mRNA. The gene-gene interaction between HLA-DPB1 and TYRO3 was not significant with regard to sensitization. The estimated proportion of atopy and allergic rhinitis cases attributable to the risk genotype was 14% and 16%, respectively. CONCLUSIONS: Our study identified TYRO3 as an important susceptibility gene to atopy and allergic rhinitis in Japanese.

Extraction and Standardization of Patient Complaints from Electronic Medication Histories for Pharmacovigilance: Natural Language Processing Analysis in Japanese.

BACKGROUND: Despite the growing number of studies using natural language processing for pharmacovigilance, there are few reports on manipulating free text patient information in Japanese. OBJECTIVE: This study aimed to establish a method of extracting and standardizing patient complaints from electronic medication histories accumulated in a Japanese community pharmacy for the detection of possible adverse drug event (ADE) signals. METHODS: Subjective information included in electronic medication history data provided by a Japanese pharmacy operating in Hiroshima, Japan from September 1, 2015 to August 31, 2016, was used as patients' complaints. We formulated search rules based on morphological analysis and daily (nonmedical) speech and developed a system that automatically executes the search rules and annotates free text data with International Classification of Diseases, Tenth Revision (ICD-10) codes. The performance of the system was evaluated through comparisons with data manually annotated by health care workers for a data set of 5000 complaints. RESULTS: Of 5000 complaints, the system annotated 2236 complaints with ICD-10 codes, whereas health care workers annotated 2348 statements. There was a match in the annotation of 1480 complaints between the system and manual work. System performance was .66 regarding precision, .63 in recall, and .65 for the F-measure. CONCLUSIONS: Our results suggest that the system may be helpful in extracting and standardizing patients' speech related to symptoms from massive amounts of free text data, replacing manual work. After improving the extraction accuracy, we expect to utilize this system to detect signals of possible ADEs from patients' complaints in the future.

Transcription Elongation Factor P-TEFb Is Involved in IL-17F Signaling in Airway Smooth Muscle Cells.

BACKGROUND: IL-17F is involved in the pathogenesis of several inflammatory diseases, including asthma and COPD. However, the effects of steroids on the function of IL-17F signaling mechanisms are largely unknown. One of the transcription elongation factors, positive transcription elongation factor b (P-TEFb) composed of cyclin T1 and cyclin-dependent kinase 9 (CDK9), is known as a novel checkpoint regulator of gene expression via bromodomain-containing protein 4 (Brd4). METHODS: Human airway smooth muscle cells were stimulated with IL-17F and the expression of IL-8 was evaluated by real-time PCR and ELISA. Next, the phosphorylation of CDK9 was determined by Western blotting. The CDK9 inhibitor and short interfering RNAs (siRNAs) targeting Brd4, cyclin T1, and CDK9 were used to identify the effect on IL-17F-induced IL-8 expression. Finally, the effect of steroids and its signaling were evaluated. RESULTS: IL-17F markedly induced the transcription of the IL-8 gene and the expression of the protein. Pretreatment of CDK9 inhibitor and transfection of siRNAs targeting CDK9 markedly abrogated IL-17F-induced IL-8 production. Transfection of siRNAs targeting Brd4 and cyclin T1 diminished IL-17F-induced phosphorylation of CDK9 and IL-8 production. Moreover, budesonide decreased CDK9 phosphorylation and markedly inhibited IL-17F-induced IL-8 production. CONCLUSIONS: This is the first report that P-TEFb is involved in IL-17F-induced IL-8 expression and that steroids diminish it via the inhibition of CDK9 phosphorylation. IL-17F and P-TEFb might be novel therapeutic targets for airway inflammatory diseases.