Multicentre evaluation of multidisciplinary team meeting agreement on diagnosis in diffuse parenchymal lung disease: a case-cohort study

BACKGROUND

Diffuse parenchymal lung disease represents a diverse and challenging group of pulmonary disorders. A consistent diagnostic approach to diffuse parenchymal lung disease is crucial if clinical trial data are to be applied to individual patients. We aimed to evaluate inter-multidisciplinary team agreement for the diagnosis of diffuse parenchymal lung disease.

METHODS

We did a multicentre evaluation of clinical data of patients who presented to the interstitial lung disease unit of the Royal Brompton and Harefield NHS Foundation Trust (London, UK; host institution) and required multidisciplinary team meeting (MDTM) characterisation between March 1, 2010, and Aug 31, 2010. Only patients whose baseline clinical, radiological, and, if biopsy was taken, pathological data were undertaken at the host institution were included. Seven MDTMs, consisting of at least one clinician, radiologist, and pathologist, from seven countries (Denmark, France, Italy, Japan, Netherlands, Portugal, and the UK) evaluated cases of diffuse parenchymal lung disease in a two-stage process between Jan 1, and Oct 15, 2015. First, the clinician, radiologist, and pathologist (if lung biopsy was completed) independently evaluated each case, selected up to five differential diagnoses from a choice of diffuse lung diseases, and chose likelihoods (censored at 5% and summing to 100% in each case) for each of their differential diagnoses, without inter-disciplinary consultation. Second, these specialists convened at an MDTM and reviewed all data, selected up to five differential diagnoses, and chose diagnosis likelihoods. We compared inter-observer and inter-MDTM agreements on patient first-choice diagnoses using Cohen's kappa coefficient (κ). We then estimated inter-observer and inter-MDTM agreement on the probability of diagnosis using weighted kappa coefficient (κw). We compared inter-observer and inter-MDTM confidence of patient first-choice diagnosis. Finally, we evaluated the prognostic significance of a first-choice diagnosis of idiopathic pulmonary fibrosis (IPF) versus not IPF for MDTMs, clinicians, and radiologists, using univariate Cox regression analysis.

FINDINGS

70 patients were included in the final study cohort. Clinicians, radiologists, pathologists, and the MDTMs assigned their patient diagnoses between Jan 1, and Oct 15, 2015. IPF made up 88 (18%) of all 490 MDTM first-choice diagnoses. Inter-MDTM agreement for first-choice diagnoses overall was moderate (κ=0·50). Inter-MDTM agreement on diagnostic likelihoods was good for IPF (κw=0·71 [IQR 0·64-0·77]) and connective tissue disease-related interstitial lung disease (κw=0·73 [0·68-0·78]); moderate for non-specific interstitial pneumonia (NSIP; κw=0·42 [0·37-0·49]); and fair for hypersensitivity pneumonitis (κw=0·29 [0·24-0·40]). High-confidence diagnoses (>65% likelihood) of IPF were given in 68 (77%) of 88 cases by MDTMs, 62 (65%) of 96 cases by clinicians, and in 57 (66%) of 86 cases by radiologists. Greater prognostic separation was shown for an MDTM diagnosis of IPF than compared with individual clinician's diagnosis of this disease in five of seven MDTMs, and radiologist's diagnosis of IPF in four of seven MDTMs.

INTERPRETATION

Agreement between MDTMs for diagnosis in diffuse lung disease is acceptable and good for a diagnosis of IPF, as validated by the non-significant greater prognostic separation of an IPF diagnosis made by MDTMs than the separation of a diagnosis made by individual clinicians or radiologists. Furthermore, MDTMs made the diagnosis of IPF with higher confidence and more frequently than did clinicians or radiologists. This difference is of particular importance, because accurate and consistent diagnoses of IPF are needed if clinical outcomes are to be optimised. Inter-multidisciplinary team agreement for a diagnosis of hypersensitivity pneumonitis is low, highlighting an urgent need for standardised diagnostic guidelines for this disease.

FUNDING

National Institute of Health Research, Imperial College London.

Evaluation of multicontrast MRI including fat suppression and inversion recovery spin echo for identification of intra-plaque hemorrhage and lipid core in human carotid plaque using the mahalanobis distance measure

Intra-plaque hemorrhage (IPH) and lipid core, characteristics of rupture prone carotid plaques, are often visualized in vivo with MRI using T1 weighted gradient and spin echo, respectively. Increasing magnetic field strength may help to identify IPH and lipid core better. As a proof of concept, automatic segmentation of plaque components was performed with the Mahalanobis distance (MD) measure derived from image contrast from multicontrast MR images including inversion recovery spin echo and T1 weighted gradient echo with fat suppression. After MRI of nine formaldehyde-fixated autopsy specimens, the MDs and Euclidean Distances between plaque component intensities were calculated for each MR weighting. The distances from the carotid bifurcation and the size and shape of calcification spots were used as landmarks for coregistration of MRI and histology. MD between collagen/cell-rich area and IPH was largest with inversion recovery spin echo (4.2/9.3, respectively), between collagen/cell-rich area/foam cells and lipid core with T1 weighted gradient echo with fat suppression (26.9/38.2/4.6, respectively). The accuracy of detection of IPH, cell-rich area, and collagen increased when the MD classifier was used compared with the Euclidean Distance classifier. The enhanced conspicuity of lipid core and IPH in human carotid artery plaque, using ex vivo T1 weighted gradient echo with fat suppression and inversion recovery spin echo MRI and MD classifiers, demands further in vivo evaluation in patients.

Molecular MRI of murine atherosclerotic plaque targeting NGAL: a protein associated with unstable human plaque characteristics

AIMS

Neutrophil gelatinase-associated lipocalin (NGAL) is an effector molecule of the innate immune system. One of its actions is the prolongation of matrix metalloproteinase-9 (MMP-9) activity by the formation of a degradation-resistant NGAL/MMP-9 complex. We studied NGAL in human atherosclerotic lesions and we examined whether NGAL could act as a target for molecular imaging of atherosclerotic plaques.

METHODS AND RESULTS

Increased levels of NGAL and the NGAL/MMP-9 complex were associated with high lipid content, high number of macrophages, high interleukin-6 (IL-6) and IL-8 levels, and low smooth muscle cell content in human atherosclerotic lesions obtained during carotid endarterectomy (n= 122). Moreover, plaque levels of NGAL tended to be higher when intra-plaque haemorrhage (IPH) or luminal thrombus was present (n= 77) than without the presence of IPH or thrombus (n= 30). MMP-9 and -8 activities were strongly related to NGAL levels. The enhancement on magnetic resonance (MR) images of the abdominal aorta of ApoE(-/-)/eNOS(-/-) mice was observed at 72 h after injection of NGAL/24p3-targeted micelles. The specificity of these results was validated by histology, and co-localization of micelles, macrophages, and NGAL/24p3 was observed.

CONCLUSION

NGAL is highly expressed in atheromatous human plaques and associated with increased MMP-9 activity. NGAL can be detected in murine atherosclerotic arteries using targeted high-resolution MR imaging. Therefore, we conclude that NGAL might serve as a novel imaging target for the detection of high-risk plaques.

Contractile and morphological properties of hamster retractor muscle following 16 h of cold preservation

INTRODUCTION

Cold hypoxia is a common factor in cold tissue preservation and mammalian hibernation. The purpose of this study was to determine the effects of cold preservation on the function of the retractor (RET) muscle of the hamster in the non-hibernating state and compare these with previously published data (van der Heijden et al., 2000) on the rat cutaneus trunci (CT) muscle.

MATERIALS AND METHODS

After cold storage (16 h at 4 degrees C), muscles were stimulated electrically to measure maximum tetanus tension (P(0)) and histologically analyzed. The protective effects of addition of the antioxidants trolox and deferiprone and the calcium release inhibitor BDM to the storage fluid were determined.

RESULTS

After storage, the twitch threshold current was increased (from 60 to 500 microA) and P(0) was decreased to 27% of control. RET morphology remained unaffected. RET muscle function was protected by trolox and deferiprone (P(0), resp., 43% and 59% of control). Addition of BDM had no effect on the RET.

CONCLUSIONS

The observed effects of cold preservation and of trolox and deferiprone on the RET were comparable to those on CT muscle function, as reported in a previously published study (van der Heijden et al., 2000). Both hamster RET and rat CT muscles show considerable functional damage due to actions of reactive oxygen species. In contrast to the CT, in the RET cold preservation-induced functional injury could not be prevented by BDM and was not accompanied by morphological damage such as necrosis and edema. This suggests that the RET myocytes possess a specific adaptation to withstand the Ca(2+) overload induced by cold ischemia.

Where to draw the mitral isthmus line in catheter ablation of atrial fibrillation: histological analysis

AIMS

A linear lesion between the left inferior pulmonary vein orifice and mitral annulus, the so-called mitral isthmus, may improve the success of catheter ablation for atrial fibrillation. Gaps in the lesion line, however, may facilitate left atrial flutter. The aim of the study was to determine the optimal location of the lesion line by serial sectioning of the isthmus area.

METHODS AND RESULTS

In a post-mortem study of 16 patients with normal left atria, serial sections of the isthmus area from 10 mm superior to and 30 mm inferior to the isthmus were studied by light microscopy. The length of the isthmus was 35+/-7 mm. On average, the muscle sleeve around the coronary sinus ended 10 mm inferior to the isthmus. The prevalence of a ramus circumflexus <5 mm from the endocardial surface, decreased from 60% in the most superior section to 0% in the most inferior section. Atrial arteries were frequently present in all sections.

CONCLUSIONS

The thickness of atrial myocardium, the ramus circumflexus sometimes very close to the endocardium, a myocardial sleeve around the coronary sinus, and local cooling by atrial arteries and veins may complicate the creation of conduction block in the mitral isthmus.