Circulating trefoil factors in relation to lung cancer, age and lung function: a cross-sectional study in patients referred for suspected lung cancer

The trefoil factor family proteins: TFF1, TFF2 and TFF3 are secreted by epithelial cells in the respiratory tract. Here, we explore circulating concentrations of the trefoil factors in relation to lung cancer, age and lung function. We included 751 patients suspected of lung cancer. Lung cancer diagnosis was based on data reported to a national database. Serum TFF1, TFF2 and TFF3 concentrations were measured by ELISA, and spirometry was performed within ±3 days of blood sampling. Forced expiratory volume in the first second (FEV1) in relation to forced vital capacity (FVC), FEV1/FVC (a parameter used to quantify reduced lung function) was recorded. Lung cancer was diagnosed in 163 (22%) patients. Circulating concentrations of TFF3 (p = .021), but not TFF1 and TFF2, were significantly elevated in cancer patients. All three trefoil factors showed an increase in concentration with increasing age (p < .001) and declining lung function (p < .004). In the present cohort, concentrations of all three peptides were elevated compared with previous results published for healthy individuals. In conclusion, we report higher concentrations of TFF3 in patients with lung cancer, while increasing age and reduced lung function are associated with increasing concentrations of all trefoil factors in this specific patient population. The results emphasize that age and lung function should be taken into consideration when evaluating concentrations of trefoil factors in patients. However, the increases in trefoil factor concentrations were relatively small, and consequently, it is unlikely that circulating trefoil factor concentrations may have a role in the diagnosis of lung cancer and lung function impairment.

Integration of cryobiopsies for interstitial lung disease diagnosis is a valid and safe diagnostic strategy-experiences based on 250 biopsy procedures

Background

Transbronchial cryobiopsies has become increasingly used in the diagnostic workup in patients suspected of having interstitial lung disease. The procedure is associated with less complications, morbidity and mortality compared to surgical lung biopsies although with a diagnostic yield that is not as high, but close to that of surgical lung biopsies. The aim of the present study was to describe the complications and diagnostic yield and their prognostic factors.

Methods

All patients undergoing transbronchial cryobiopsies at the Department of Respiratory Diseases and Allergy, Aarhus University Hospital, were included in this prospective observational cohort study.

Results

A total of 250 patients were included [61% male, mean age 66 years (range, 22–81 years)]. Pneumothorax was detected in 70 (28%) of the patients, moderate hemorrhage in 53 (21%) and severe hemorrhage in 2 (1%) of the patients. Hemorrhage was associated with central biopsies, but not with anticoagulant therapy. None of the complications were related to lung function, exercise capacity, biopsy or probe size. Only one patient experienced an acute exacerbation. Three-month mortality was 0.4% (1 patient), caused by cancer and unrelated to the procedure. Cryobiopsies contributed to the final diagnosis in 72% of the patients and after multidisciplinary team discussion, a consensus diagnosis was obtained in 82% of the patients. The gender, the total sum of biopsy sizes, number of biopsies and presence of more than 50% alveolar tissue in biopsies increased the diagnostic yield.

Conclusions

Our study confirms that using cryobiopsies in the diagnostic setup for interstitial lung diseases is safe with a limited risk of acute exacerbations and mortality. Cryobiopsies contribute to the diagnosis in the majority of patients.

Development of a novel assay for IGFBP-2 complexed with IGF-I and-II in human serum

BACKGROUND

Insulin-like growth factor binding-protein 2 (IGFBP-2) was originally identified as an IGF-carrier, governing IGF half-life, tissue accessibility and biological effects. Later, IGFBP-2 was discovered to possess IGF-independent effects. IGFBP-2 circulates in several forms, as free protein, complexed with IGF-I or IGF-II, or as IGFBP-2 fragments. The various IGFBP-2 forms are all included when measuring serum IGFBP-2 concentrations by immunoassay (i.e., immunoreactive (ir-)IGFBP-2). In this study, we describe a novel method to measure the amount of IGF that circulates bound to IGFBP-2.

METHOD

IGFBP-2 was immunoprecipitated from human serum using magnetic beads, which were subsequently eluted by acidification. After neutralization, eluates were assayed for ir-IGFBP-2, IGF-I and IGF-II and compared to serum concentrations. This allowed measurement of IGFBP-2-compexed IGF-I and IGF-II, respectively. To test the method clinically, serum from 146 patients with lung cancer, 151 patients with non-cancer pulmonary diseases and 28 healthy controls were analyzed.

RESULTS

We immuno-precipitated 97 ± 3.3% of serum IGFBP-2 and recovered > 75% of IGFBP-2-complexed IGFs, with intra- and inter-assay coefficient of variations (CVs) averaging < 5% and < 13%, respectively. No co-precipitation with IGFBP-1, -3 or - 4 was detected. Serum levels of ir-IGFBP-2 (median [25;75%]) differed between groups (cancer patients vs. non-cancer patients vs. healthy controls): 342 [260;480] vs. 262 [189;388] vs. 190 [141;269] μg/l (p < .0001). In parallel with this, concentrations of IGF-II carried by IGFBP-2 averaged: 45.0 [33.3;52.5] vs. 34.2 [25.4;46.1] vs. 19.8 [14.1;26.0] μg/l (p < .0001), and concentrations of IGF-I 8.0 [5.2;11.8] vs. 5.4 [3.6;7.3] vs. 7.0 [3.8;13.0] μg/l (p < .0001). Thus, IGFBP-2 carried more IGF-II than IGF-I in all groups (p < .0001). When expressed relative to IGF-concentrations, IGFBP-2 carried 9.0 [5.3;15.5] % of the IGF-I and 4.8 [2.9;5.8] % of the IGF-II in serum from healthy subjects. Notably, in patients, IGFBP-2 carried relatively less IGF-I, but more IGF-II (p < .0001).

CONCLUSION

Using our novel assay, we demonstrate: that IGFBP-2 carries ≈10% of circulating IGF-I and ≈5% of circulating IGF-II in healthy subjects; that IGF-II is the primary ligand for IGFBP-2; and that IGFBP-2 carries even more IGF-II in patients than in healthy subjects. Thus, our assay may provide information on IGFBP-2 beyond what is achievable by simply measuring ir-IGFBP-2.

[Medical thoracoscopy in the elucidationof recurrent pleural effusion]

Medical thoracoscopy allows the respiratory physician access to inspection and biopsy of the pleura. The method has several names, such as pleuroscopy, non-intubated thoracoscopy and exploratory thoracoscopy, all of which cover the same procedure. The main indication for medical thoracoscopy is the diagnosis of recurrent pleural effusion, where pleural biopsy is needed. Medical thoracoscopy differs from thoracic surgical surgery as patients are sedated rather than in general anaesthesia. This is a review of the state of the art of pulmonological investigations of recurrent pleural effusion and the important role of medical thoracoscopy.

Pregnancy-Associated Plasma Protein-A2 Is Associated With Mortality in Patients With Lung Cancer

Pregnancy-associated plasma protein-A (PAPP-A) and its homolog PAPP-A2 are enzymes that modulate the availability and mitogenic activity of insulin-like growth factor-I (IGF-I). PAPP-A has been implicated in numerous cancers but reports on PAPP-A2 in malignancy are non-existent. In a prospective observational study of 689 patients under suspicion of lung cancer, we examined levels of PAPP-A and PAPP-A2 and their relationship with mortality. Serum PAPP-A and PAPP-A2 concentrations were determined in pre-diagnostic blood samples using ELISA, and immunohistochemical staining of PAPP-A and PAPP-A2 was performed in malignant tissue from five operable patients. A total of 144 patients were diagnosed with lung cancer, whereas the diagnosis was rejected in 545 subjects, who served as a control group. PAPP-A2 concentrations were higher in patients with lung cancer [median (IQR): 0.33 (0.21-0.56) ng/mL] than in controls [0.27 (0.17-0.39) ng/mL], p < 0.001, whereas PAPP-A levels did not differ. Presence of PAPP-A and PAPP-A2 were confirmed in tumor specimens, and staining occurred in a heterogeneous pattern. Patients were observed for a median (range) of 7 (6; 8) years, during which 114 patients (79.2%) died. Patient mortality differed according to PAPP-A2 tertile (p < 0.001). PAPP-A2 was associated with mortality with an unadjusted hazard ratio (95% CI) per doubling in protein concentration of 1.30 (1.12; 1.53), p = 0.001. In a multivariable model adjusted for age, sex, and BMI, PAPP-A2 remained predictive of the endpoint with a hazard ratio per doubling in protein concentration of 1.25 (1.05; 1.48), p = 0.013. Collectively, PAPP-A2, but not PAPP-A, is elevated in patients with lung cancer and associated with mortality. This novel role of PAPP-A2 in cancer warrants further functional studies as well as validation in external cohorts.

Introduction of cryobiopsies in the diagnostics of interstitial lung diseases - experiences in a referral center

Introduction: Transbronchial cryobiopsies (cTBB) has emerged as a new method for obtaining lung tissue biopsies in the diagnosis of interstitial lung diseases (ILDs). Until now, it has been used in a few highly specialized interventional centers and has shown promising results in obtaining a definite diagnosis of ILDs. Method: All patients undergoing a cTBB between November 2015 and June 2016 were included in this case series study. Data on patient demographics, high-resolution computed tomography patterns, size and number of biopsies, histology patterns, the contribution to a confident diagnosis and complications were registered. Results: Thirty-eight patients underwent cTBB in the period. cTBB contributed to the diagnosis in 28 (74%) of the 38 patients. Only few complications were observed; pneumothorax was the most frequent complication (10 patients, 26%). In six patients, local bleeding occurred during the procedure and was easily controlled by a Fogarty catheter balloon and in some cases tranexamic acid. Conclusion: Performing cTBB in the diagnostics of ILDs is a safe and feasible procedure. cTBB resulted in a confident diagnosis in 74% of cases.