[French practical guidelines for the diagnosis and management of IPF - 2021 update, full version]

BACKGROUND

Since the previous French guidelines were published in 2017, substantial additional knowledge about idiopathic pulmonary fibrosis has accumulated.

METHODS

Under the auspices of the French-speaking Learned Society of Pulmonology and at the initiative of the coordinating reference center, practical guidelines for treatment of rare pulmonary diseases have been established. They were elaborated by groups of writers, reviewers and coordinators with the help of the OrphaLung network, as well as pulmonologists with varying practice modalities, radiologists, pathologists, a general practitioner, a head nurse, and a patients' association. The method was developed according to rules entitled "Good clinical practice" in the overall framework of the "Guidelines for clinical practice" of the official French health authority (HAS), taking into account the results of an online vote using a Likert scale.

RESULTS

After analysis of the literature, 54 recommendations were formulated, improved, and validated by the working groups. The recommendations covered a wide-ranging aspects of the disease and its treatment: epidemiology, diagnostic modalities, quality criteria and interpretation of chest CT, indication and modalities of lung biopsy, etiologic workup, approach to familial disease entailing indications and modalities of genetic testing, evaluation of possible functional impairments and prognosis, indications for and use of antifibrotic therapy, lung transplantation, symptom management, comorbidities and complications, treatment of chronic respiratory failure, diagnosis and management of acute exacerbations of fibrosis.

CONCLUSION

These evidence-based guidelines are aimed at guiding the diagnosis and the management in clinical practice of idiopathic pulmonary fibrosis.

[French practical guidelines for the diagnosis and management of IPF - 2021 update, short version]

BACKGROUND

Since the previous French guidelines were published in 2017, substantial additional knowledge about idiopathic pulmonary fibrosis has accumulated.

METHODS

Under the auspices of the French-speaking Learned Society of Pulmonology and at the initiative of the coordinating reference center, practical guidelines for treatment of rare pulmonary diseases have been established. They were elaborated by groups of writers, reviewers and coordinators with the help of the OrphaLung network, as well as pulmonologists with varying practice modalities, radiologists, pathologists, a general practitioner, a head nurse, and a patients' association. The method was developed according to rules entitled "Good clinical practice" in the overall framework of the "Guidelines for clinical practice" of the official French health authority (HAS), taking into account the results of an online vote using a Likert scale.

RESULTS

After analysis of the literature, 54 recommendations were formulated, improved, and validated by the working groups. The recommendations covered a wide-ranging aspects of the disease and its treatment: epidemiology, diagnostic modalities, quality criteria and interpretation of chest CT, indication and modalities of lung biopsy, etiologic workup, approach to familial disease entailing indications and modalities of genetic testing, evaluation of possible functional impairments and prognosis, indications for and use of antifibrotic therapy, lung transplantation, symptom management, comorbidities and complications, treatment of chronic respiratory failure, diagnosis and management of acute exacerbations of fibrosis.

CONCLUSION

These evidence-based guidelines are aimed at guiding the diagnosis and the management in clinical practice of idiopathic pulmonary fibrosis.

Diagnostic efficacy of ultrasound-guided core-needle biopsy of peripheral lymph nodes in sarcoidosis

BACKGROUND

Core-needle biopsy guided by ultrasound can be performed for investigating peripheral lymph node (PLN). The aim of this study was to determine the efficacy of this technique in sarcoidosis.

METHODS

Retrospective review of files of all patients in the database of the radiology department of Avicenne university hospital who underwent PLN biopsies guided by ultrasound from January 2008 to June 2011 (n=292). Cases with either granulomas at histology with the procedure or with a final diagnosis of sarcoidosis were included in the study.

RESULTS

The histological specimens were adequate in 282 out of 292 cases (96%) showing non-caseating granulomas in 22 cases (n=20 patients with a final diagnosis of sarcoidosis and n=2 patients with tuberculosis). After reviewing clinical files of the 282 patient, 22 were confirmed to have sarcoidosis, at initial presentation (n=19) or later during flare-up or relapse (n=3) with only 2 patients having no granuloma on PLN biopsy. PLN were palpable in 18 cases and only detected by (18F)FDG-PET/CT showing increased PLN uptake in 4 cases. The sensitivity and specificity of adequate biopsy were 91 and 99% and the positive and negative predictive values were 91 and 99%, respectively.

CONCLUSION

Core-needle biopsy guided by ultrasound has a high efficacy for evidencing granulomas in sarcoidosis patients with PLN involvement either clinically palpable or in the presence of (18F)FDG-PET/CT uptake.

[Lymphatics in non-tumoral pulmonary diseases. Review]

Whereas lymphatics in pulmonary non-tumoral diseases have been less studied than blood microcirculation, they clearly play a significant role. This review is a short update on lymphatics in various non-tumoral pulmonary diseases, from asthma to interstitial pneumonitis, excluding lymphangioleiomyomatosis. A lymphatic remodelling has been evidenced in asthma as well as in acute or chronic (UIP as NSIP) interstitial lung diseases. Such a remodelling can be explained as a side effect of local changes in fluidics but could also be an active player in the fibrosing process. Moreover the association of juxta-alveloar lymphatics and granulomas provides new insights in the emergence of these lesions in pulmonary sarcoidosis.

[The small airways: normal histology and the main histopathological lesions]

Lesions of the small airway are observed in a wide variety of pulmonary conditions, most of which are due to infection, tobacco and connective tissue diseases. They are sometimes isolated or, more often, associated with involvement of other pulmonary structures such as the bronchi, the lung parenchyma and the pleura. The pathological spectrum of the bronchiolar response to injury is relatively limited. Thus, the same lesion is observed in various clinical settings. There is no correlation between the severity of the small airway involvement seen by the pathologist and the clinical and functional manifestations of bronchiolitis. The causes of bronchiolitis may be classified on a clinical basis, on aetiology or on histological appearance, yet no single classification appears to be suitable. An integrated clinical, radiological, functional and histological approach is needed. As they are seen by the pathologist microscopically, small airway lesions may be subdivided into three categories: (1) simple nonspecific lesions (bronchiolitis - cellular, follicular, granulomatous, obliterative, constrictive) that are never exclusively related to one clinical picture, (2) or displaying a more specific pattern like the respiratory bronchiolitis of the smoker or the histolgical changes of asthma, (3) bronchiolar lesions in conditions described as "interstitial", predominantly centrilobular, involving the small airways and the lung parenchyma, and visible radiologically. After recalling the normal histological appearances of the bronchioles, this review describes the diversity of the histopathological lesions of the small airways.

[Lymphatic vascular system, development and lymph formation. Review]

The lymphatic vascular system is widely developed among vertebrates. Lymphatic vessels provide the interstitial fluid (20% of the body weight) drainage through interstitial prelymphatic channels, capillaries, precollectors and collectors flowing into the venous blood. Endothelial cells of capillaries are overlapped and fixed to interstitial collagen and elastic fibres by anchoring filaments facilitating the fluid transfer. Precollectors and collectors have valves controlling the lymph flux direction. In addition to external mechanisms, the lymphangions of collectors have contracting muscle cells driving the flow. Lymphatic endothelial cells are routinely identified by the expression of podoplanin, LYVE-1 and VEGFR3. In the embryo, prelymphatic endothelial cells emerge from the cardinal veins and migrate into the mesenchyma forming embryonic lymphatic sacs. Prox1, Sox18 and COUP-TFII play a major role in the endothelial speciation, VEGFC as VEGFD combined to VEGFR3 in cell migration and proliferation and FoxC2 in valves development. In cancer or inflammation, various factors secreted by cancer cells and/or inflammatory cells induce a neolymphangiogenesis. Recently it has been shown that cells from the bone marrow could be potential precursors for lymphatic endothelial cells.

Lymphatic and blood microvasculature organisation in pulmonary sarcoid granulomas

Pulmonary sarcoid granulomas are characterised by their elective distribution along collecting lymphatics. However, relationships between granulomas and intralobular lymphatics or blood microvascularisation have not been investigated. Therefore, we undertook a specific analysis of blood capillaries and lymphatics supplying sarcoid granulomas to identify additional clues to understanding the pathophysiogenesis of these lesions. Six pulmonary samples were immunolabelled with D2-40, anti-CD34 and anti-CD31 antibodies, paying particular attention to the relationships between lymphatics and granulomas, and the pattern of blood microvessels supplying sarcoid lesions. A morphometric study of granulomas included their distance to lymphatics and a three-dimensional reconstruction of a granuloma in its lymphatic context. Intralobular granulomas were closely associated with lymphatics; apart from a few granulomas, blood capillaries stopped at the outer border of the fibrous ring surrounding granulomas, and perigranuloma capillaries were particularly scarce. Our observations of the lymphatic and blood microvascular environment of intralobular pulmonary sarcoid granulomas provide evidence for the critical role of lymphatics in the emergence of these lesions. Moreover, pulmonary sarcoid lesions could be considered avascular structures, thereby providing new insights into the understanding of the granuloma physiology and the distribution of blood-borne therapeutic agents.

[Interstitial lung disease in systemic sclerosis]

INTRODUCTION

Interstitial lung diseases (ILD) in systemic sclerosis (SSc) are mainly encountered in patients with diffuse disease although they may occur less frequently in patients with limited cutaneous disease.

BACKGROUND

In SSc early detection of ILD should be achieved by high resolution computed tomography and pulmonary function tests, including measurement of DLCO. In total up to 75% of patients with SSc develop ILD but it is progressive in only a minority of patients. Unlike idiopathic ILD, SSc associated ILD corresponds to non-specific interstitial pneumonia rather than usual interstitial pneumonia in the majority of cases. This explains the better prognosis of SSc associated ILD compared with idiopathic ILD. Nevertheless ILD represents one of the two main causes of death in SSc.

VIEWPOINT

The treatment of SSc associated ILD is not well established. Anti-fibrosing treatments have failed to demonstrate benefit and cyclophosphamide, which has been used for about 15 years in the treatment of this condition, has recently been evaluated in two prospective randomised studies which showed a significant but modest effect on respiratory function.

CONCLUSION

A subgroup of patients with rapidly progressive ILD might benefit from pulsed intravenous cyclophosphamide combined with prednisone 15 mg daily, but this remains to be confirmed.

Characterisation of dendritic cell subsets in lung cancer micro-environments

The aim of the current study was to seek evidence for a correlation between mediators present in lung cancer micro-environments and subsets of dendritic cells (DCs) infiltrating these tumours. Immunohistochemistry and recently available antibodies were used to define the phenotype of DCs present in surgical biopsies from 12 patients with lung carcinomas, and the local expression of chemokines potentially involved in the recruitment of these cells was evaluated, both at mRNA and protein levels. Real-time PCR was used to analyse the expression of mRNA coding for cytokines known to influence the maturation of DCs in vitro. Different subsets of myeloid DCs were present in lung cancers, but no plasmocytoid DCs were identified. Both Langerhans cells and CD1a+/Langerin cells were interspersed among tumour cells, in numbers that were correlated to the amounts of CC chemokine ligand 20 produced in these tumours. In most specimens, DC-specific intercellular adhesion molecule-grabbing nonintegrin-positive DCs were also present at the periphery of the tumour beds. No DC-lysosomal associated membrane protein-positive DCs were identified and CD83+ DCs were rarely present in the tumour stroma. All tumours expressed interleukin (IL)-10, transforming growth factor-beta and vascular endothelial growth factor, whereas IL-12 was virtually absent. Thus, various types of dendritic cells infiltrate lung carcinomas and display an immature phenotype, presumably because of the inhibitory cytokine micro-environment.

Temporal artery biopsy for diagnosing giant cell arteritis: the longer, the better?

OBJECTIVE

To investigate the relation between temporal artery biopsy (TAB) length and diagnostic sensitivity for giant cell arteritis.

METHODS

Histological TAB reports generated from four hospital pathology departments were reviewed for demographics, histological findings, and formalin fixed TAB lengths. A biopsy was considered positive for giant cell arteritis if there was a mononuclear cell infiltrate predominating at the media-intima junction or in the media.

RESULTS

Among 1821 TAB reports reviewed, 287 (15.8%) were excluded because of missing data, sampling errors, or age < 50 years. Mean TAB length of the 1520 datasets finally analysed (67.2% women; mean (SD) age, 73.1 (10.0) years) was 1.33 (0.73) cm. Histological evidence of giant cell arteritis was found in 223 specimens (14.7%), among which 164 (73.5%) contained giant cells. Statistical analyses, including piecewise logistic regression, identified 0.5 cm as the TAB length change point for diagnostic sensitivity. Compared with TAB length of < 0.5 cm, the respective odds ratios for positive TAB without and with multinucleated giant cells in samples > or = 0.5 cm long were 5.7 (95% confidence interval, 1.4 to 23.6) and 4.0 (0.97 to 16.5).

CONCLUSIONS

A fixed TAB length of at least 0.5 cm could be sufficient to make a histological diagnosis of giant cell arteritis.

Expression of apoptosis-regulatory proteins in lesions of pulmonary Langerhans cell histiocytosis

AIMS

Pulmonary Langerhans cell histiocytosis (PLCH) is characterized by the presence of lesions containing numerous activated Langerhans cells (LCs). An uncontrolled immune response sustained by activated LCs seems to be involved in the pathogenesis of the disease. The aim of this study was to establish whether disruption of LC apoptosis related to the expression of the Bcl-2 family proteins is implicated in the maintenance of PLCH lesions.

METHODS

Six patients with PLCH were evaluated by morphological and immunohistochemical techniques to explore the incidence of apoptosis in pathological LCs and to characterize the expression of Bcl-2-related proteins by these cells.

RESULTS

Very few LCs present in PLCH lesions exhibited nuclear apoptotic changes or expressed cleaved caspase-3, whereas they all strongly expressed the anti-apoptotic molecule Bcl-x(L). Interestingly, pulmonary LCs present in intervening lung tissue not involved by the pathological process and known to be immature dendritic cells did not express Bcl-2 family proteins.

CONCLUSIONS

These findings suggest that activated LCs present within PLCH lesions are poorly susceptible to apoptosis and, thus, are able to sustain the pathological process by causing continuous local stimulation of T cells. Functional studies are needed, however, to demonstrate that they are actually resistant to programmed cell death.

Long-term survival of patients given hormonal therapy for metastatic endometrial stromal sarcoma

Endometrial stromal sarcoma (ESS) is a rare neoplasm, mainly observed in premenopausal women. We describe two women 44 and 34 years old at the time ESS diagnosis, who developed lung metastases 3 and 6 years, respectively, after initial treatment: hysterectomy without (case 1) or with oophorectomy (case 2), followed by hormone replacement therapy (HRT) for the latter. Their estrogen (ER) and progesterone receptors (PR) were analyzed biochemically in metastatic lung tissue, yielding respective concentrations of ER 242 and 184, and PR 910 and 100 fmol/mg of cytosol protein. Both patients started treatment with the aromatase inhibitor aminoglutethimide (500 mg qid) after surgery for the first patient and after stopping HRT for the second. Under aromatase-inhibitor therapy, both patients achieved a complete response, patient 1 remains disease- free with 14+ years of follow-up, and patient 2 with 7+ years. Our data suggest that an aromatase inhibitor may be an effective treatment for ESS. Furthermore, routine ER and PR analyses could be useful to predict the response to hormonal therapy in ESS.

Cytokine profiles in idiopathic pulmonary fibrosis suggest an important role for TGF-beta and IL-10

Modulation of cytokine expression represents a potentially useful approach for the treatment of idiopathic pulmonary fibrosis (IPF). To identify potential targets for such intervention, semi-quantitative reverse transcriptase-polymerase chain reaction was used to compare the expression of messenger ribonucleic acids (mRNAs) coding for 17 cytokines in lung tissue obtained from patients with IPF at the time of diagnosis and control subjects. Some cytokines were also studied at the protein level by immunohistochemical techniques. mRNAs coding for all of the cytokines evaluated were detected in both control and fibrotic lung samples. Only transforming growth factor (TGF)-beta and interleukin (IL)-10 mRNAs were quantitatively increased in lung biopsies from patients with IPF compared with those of controls, results confirmed at the protein level by immunohistochemistry. Although mRNAs for platelet-derived growth factor (PDGF)-BB and keratinocyte growth factor (KGF) were expressed in similar amounts in lungs from patients with IPF and controls, localised accumulation of both factors was also observed in IPF. Hyperplastic alveolar epithelial cells were a prominent source of cytokines, where IL-10, PDGF-BB and KGF were present in increased amounts, although increased accumulation in fibroblasts, smooth-muscle cells and matrix components was also observed (PDGF-BB, TGF-beta). These results offer new insights into the cytokines produced in the lung in idiopathic pulmonary fibrosis and suggest that modulation of the production of transforming growth factor-beta and interleukin-10 may represent a potentially useful therapeutic strategy for this disabling disease.

[Isolated pleural metastases from an atypical meningioma]

INTRODUCTION

Less than 2 per 1,000 meningiomas are complicated by extra-cranial metastases. These are most often found in the lung parenchyma, liver or lymph nodes. They almost always occur in anaplastic meningiomas (grade III according to OMS) and much more rarely in atypical meningiomas (grade II).

CASE REPORT

We report a case of pleural metastases from a primary frontal atypical meningioma with no other extra-cranial spread.

CONCLUSION

Poorly differentiated meningioma presents many morphological and immuno-histochemical similarities to malignant mesothelioma. For this reason the diagnosis of pleural metastase from a meningioma cannot be made without knowledge of the primary meningeal tumour and its histological type.

Low grade marginal zone B cell lymphoma of the breast associated with localised amyloidosis and corpora amylacea in a woman with long standing primary Sjögren's syndrome

Primary low grade marginal zone B cell lymphoma (MZL) of the breast and localised mammary amyloidosis are exceedingly rare entities. This report describes the case of a woman with long standing Sjögren's syndrome presenting with asymptomatic MZL of the breast showing plasmacytic differentiation, associated with local ductular amyloidosis. The lesion was discovered incidentally in breast tissue resected for microcalcifications. Immunohistochemistry revealed kappa light chain restriction, supporting the neoplastic nature of the infiltrate. A retrospective molecular study of the salivary gland biopsy showed a B cell clone. This is the first report of the association of human mammary ductular amyloidosis with cartwheel shaped material identical to corpora amylacea, usually seen in brain, lung, and prostate, but unknown in the human breast. The excellent outcome without treatment seen in this patient further emphasises the need to distinguish between MZL with plasmacytic differentiation and extramedullary plasmacytoma.

Magnetic resonance imaging of skeletal muscle involvement in limb restricted vasculitis

BACKGROUND

Limb restricted polyarteritis nodosa (PAN) and PAN-type diseases such as isolated vasculitis of skeletal muscle are localised vasculitides affecting the skin, muscles, or peripheral nerves, usually of the lower limbs. These diseases often present with non-specific clinical symptoms and normal laboratory values and electromyograms. The usefulness of magnetic resonance imaging (MRI) of skeletal muscle has been poorly investigated to date.

OBJECTIVE

To describe the MRI findings in the legs of three patients with limb restricted vasculitides (two PAN, one isolated vasculitis of the skeletal muscle) with histologically established muscle involvement.

METHODS

MRI was carried out on calf muscles and T(2) weighted images, unenhanced T(1) weighted images, and STIR sequences were obtained.

RESULTS

Muscle damage resulted in oedema-like changes on MRI characterised by hyperintense signals in T(2) weighted and slow tau inversion recovery (STIR) sequences and normal unenhanced T(1) weighted sequences of one or several leg muscles.

CONCLUSIONS

MRI should be considered a useful complementary examination that might facilitate the recognition of limb restricted vasculitides, and possibly indicate the site for muscle biopsy. It could also be useful in monitoring the course of the disease. Future studies should also evaluate MRI for systemic PAN or other systemic vasculitides with muscle involvement.

Churg-Strauss syndrome in two patients receiving montelukast

OBJECTIVE

Churg-Strauss syndrome (CSS) has been described in association with the treatment of asthmatic patients with leukotriene receptor antagonist. The main mechanism proposed to explain this condition is the unmasking of CSS after the leukotriene receptor antagonist has allowed corticosteroid tapering. Other hypotheses might be proposed.

METHODS

We describe two patients who developed CSS after starting treatment with montelukast, a new antileukotriene drug.

RESULTS

Both patients presented with CSS after 4-5 months of treatment with montelukast. Neither patient received long-term systemic steroids for asthma, but both were on inhaled steroids. One patient had a myocardial involvement and experienced a stroke. Our two patients were treated with systemic steroids and cyclophosphamide.

CONCLUSIONS

CSS does not appear to relate to steroid tapering in our patients. The other hypotheses are a coincidence or a direct adverse effect of the antileukotriene. Long-term data on these drugs are lacking and leukotriene's role in vasculitis remains to be elucidated.

[Inflammatory pseudotumors of the lung with severe course]

Pulmonary inflammatory pseudotumors are usually unique lesions of unknown etiology with good prognosis. We report two severe cases with mediastinal invasion, local recurrence, extrathoracic locations, one of them with a fatal evolution. Certain microscopic features, which were present in our cases (increased cellularity, nuclear pleomorphism, mitotic activity, focal necrosis, bizarre giant cells, vascular invasion), may have prognostic relevance in determining an aggressive behavior of these tumors. Surgical resection is the recommended treatment, and incomplete resection, as in our cases, seems to be a risk factor for developing recurrent inflammatory pseudotumor. Immunosuppressive therapy was ineffective as well as radiotherapy in one of our cases. Only high doses of corticosteroids seemed to slow the evolution of the disease.

Low expression of bcl-2 in Brca1-associated breast cancers

Little data are available concerning the molecular mechanisms of action of Brca1 and Brca2 in breast oncogenesis. Recent experimental results suggest that Brca1 plays a role in the regulation of apoptosis. In order to determine whether the analysis of human tumours would provide data supporting this hypothesis, we have assessed the expression of the antiapoptotic bcl-2 and of the proapoptotic p53 genes in Brca1 - and Brca2 -associated breast carcinomas. The levels of expression of these genes were compared to those observed in controls and to the mitotic and the apoptotic indexes. Our series were composed of 16 cases of breast carcinoma in women with a germline Brca1 gene mutation, and of four cases with Brca2 mutation. A group of 39 patients aged under 36 years and for whom the search for Brca1 gene mutations was negative, and a group of 36 cases of sporadic cancers without data on their Brca status were used as controls. Immunohistochemistry was used to detect p53 and bcl-2 gene products. Mitotic and apoptotic indexes were higher in Brca1 -associated tumours than in controls. No significant difference in p53 immunostaining was observed between the four groups of patients. In contrast, the rate of bcl-2 -positive tumours was lower (31%) in Brca1 -carcinomas than in carcinomas without Brca1 mutation (90%) (P< 10(-3)). A strong Bcl-2 expression was found in the four cases of Brca2 -associated carcinomas. No significant correlation was observed between p53 and Bcl-2 immunostainings, either in cases or in controls. The association between Brca1 status and Bcl-2 expression remained significant after adjustment for the oestrogen receptor status. Our study shows that a low expression of bcl-2 characterises most Brca1 -associated breast carcinomas, a biological trait which seems not to be shared by Brca2 -associated tumours nor to be related to oestrogen receptor and/or p53 status. bcl-2 might thus be one of the target genes involved in the oncogenesis related to Brca1 and its down-regulation may account for the increased apoptosis and the high proliferative rate observed in Brca1 -associated carcinomas.

Bilateral hemothorax revealing mediastinal parathyroid adenoma

We report the case of a 63-year-old woman admitted to hospital because of bilateral hemothorax associated with acute respiratory failure and laterotracheal neoformation. A right thoracoscopy biopsy revealed a paratracheal parathyroid adenoma which was responsible for bilateral hemothorax and primary hyperparathyroidism. A curative resection was successfully performed by cervicotomy.

Is high-resolution computed tomography a reliable tool to predict the histopathological activity of pulmonary Langerhans cell histiocytosis?

High-resolution computed tomography (HRCT) has proved to be very useful in the diagnosis and follow-up of pulmonary Langerhans cell histiocytosis (PLCH), but the precise relationships between nodules and thin-wall cysts observed by HRCT, and granulomatous or cystic lesions present in lung tissue, remain to be established. The aim of this study was to compare quantitative data obtained by HRCT and those obtained by histopathological examination of corresponding lung tissue specimens in patients with biopsy-proven PLCH. The results demonstrated that the extent of nodular abnormalities was strongly correlated with the density of florid granulomatous lesions in lung tissue. A strong correlation was also found between the extent of cystic abnormalities and the density of cavitary lesions, but the latter included both still inflammatory cavitary granulomas and cicatricial fibrous cysts. Interestingly, small isolated florid granulomas were found in lung tissue from most patients with a predominant cystic CT scan pattern. Taken together, these results demonstrate that HRCT has to be considered with caution to evaluate the histopathological activity of PLCH. Patients presenting with predominant HRCT cystic abnormalities should benefit from a long-term follow-up. Because these patients are susceptible to developing severe respiratory insufficiency, they should also be considered for treatment as soon as an effective therapy for LCH is available.

Detection of codon 12 K-ras mutations in non-neoplastic mucosa from bronchial carina in patients with lung adenocarcinomas

K-ras activation by point mutation in codon 12 has been reported in lung adenocarcinomas in various models of experimental lung tumours induced by chemical carcinogens. The hypothesis of the presence of cells containing K-ras mutation in non neoplastic bronchial carina, the main site of impaction of airborne contaminants, was investigated by evaluating concurrent lung tumour and non-neoplastic proximal bronchial carinae from 19 patients with lung adenocarcinomas. The restriction fragment length polymorphism enriched PCR method used can detect one mutant allele among 10(3) normal alleles. A mutation was detected in 42% of lung adenocarcinoma samples. No mutation was detected in either tumour or bronchial carinae in nine patients (47%). K-ras mutation was detected in the lung tumour but not in bronchial carinae in four patients (21%), in both the lung tumour and bronchial carinae in four other patients (21%). In two patients (11%), K-ras mutation was detected in at least one bronchial carina, but not in the lung tumour. Mutations of codon 12, confirmed by sequencing analysis of ten samples, were G to T transversion, mostly TGT and GTT in bronchial carinae and lung tumours. Our data show that activated K-ras by point mutation can be present in non-neoplastic bronchial carina mucosa even when no mutation is detected in tumour samples.

Replacement of a tracheal segment by a mixed graft (aorta and prosthesis): an experimental study in rabbits

OBJECTIVE

To develop a new graft and to verify its technical feasibility, viability, and ability to reduce the risk of infection by interposition of an aortic segment between the airway and the prosthetic component of the graft.

DESIGN

Experimental study.

SETTING

Multicentre study, France.

ANIMALS

38 New Zealand rabbits.

INTRODUCTION

A 1 cm aortic segment was obtained from the thoracic aorta of a rabbit and cryopreserved or stored at +4 degrees C. The aortic segment, surrounded by a ringed expanded polytetrafluoroethylene (ePTFE) prosthesis was used to replace 1 cm of cervical trachea in two groups of rabbits, either with cryopreserved or fresh aorta.

MAIN OUTCOME MEASURES

Macroscopic, microbiological, and histological studies four months later.

RESULTS

12/20 animals in the cryopreserved group survived and 13/18 in those had had fresh aorta inserted. Partial or total necrosis of the aortic muscular layer was replaced by connective tissue, which was a guide for epithelialisation from the anastomoses.

CONCLUSION

This new graft is worthy of further investigation, as it is technically feasible and easy to insert.

Familial extensive idiopathic bilateral pleural fibrosis

The authors report three sisters with bilateral isolated apical pleural fibrosis of unknown origin, which did not respond to empirical antituberculosis therapy and oral corticosteroids. The disease evolved in an unrelenting fashion producing pleural fibrosis at the lung bases and leading to the death of two sisters and to lung transplantation in the other one. There was no history of other familial disease or consanguinity. The particular features of these cases and the differences from other reports of apparently cryptogenic pleural fibrosis are outlined.

Langerhans cells in Langerhans cell granulomatosis are not actively proliferating cells

Pulmonary Langerhans cell granulomatosis (LCG), also called histiocytosis X, is a disorder of unknown etiology characterized by the presence of destructive granulomas containing numerous Langerhans cells (LCs). The process may be localized or multifocal, and it remains unclear whether the same pathogenic mechanism is involved in all forms of the disease. It is often assumed that the massive accumulation of LCs at the sites of the lesions results from the abnormal proliferation of these cells, although it has been suggested that LCG in adults, at least in the lung, could be a reactive disorder initiated by activated LCs. Little is known, however, concerning the mechanisms responsible for the accumulation of large numbers of LCs in the course of the disease, and the relative contribution of recruitment and local proliferation of these cells remains to be established. To investigate this question, the proportion of replicating LCs was evaluated in biopsied granulomas from patients with localized or diffuse form of LCG by means of several histopathological techniques currently used in assessment of cell proliferation. The findings demonstrate that, except for proliferating cell nuclear antigen (PCNA), all parameters measured are low in all forms of the disease. They are similar to those of renewing epithelial cells and clearly less than those of neoplastic cells. These data strongly suggest that LCs in LCG granulomas are not a rapidly dividing cell population and that local LC replication makes only a minimal contribution to granuloma maintenance. Caution appears to be necessary in the use of PCNA as a marker of growth fraction.

Cytokine patterns in tuberculous and sarcoid granulomas: correlations with histopathologic features of the granulomatous response

Cytokines play an important role in granuloma formation, but the extent that cytokine profiles are similar in different granulomatous diseases and whether differences in the histopathologic features of the granulomatous response results from differences in cytokine production have not been evaluated. To investigate these questions, we used RT-PCR to quantify the expression of mRNAs coding for 16 cytokines in granulomatous lymph nodes from patients with tuberculosis and sarcoidosis and from control tissues, and we sought correlations between the level of expression of these cytokines and the histopathologic features of the granulomas. Expression of mRNAs coding for a number of cytokines (IL-1beta, IFN-gamma, TNF-alpha, granulocyte-macrophage (GM)-CSF, IL-12 (p40), and lymphotoxin-beta) was increased in tuberculous and sarcoid granulomas compared with that of control tissues. All sarcoid granulomas were shown to express a Th1 pattern of cytokine mRNAs, while tuberculous lymph nodes expressed either a Th1 or a Th0 profile. GM-CSF and lymphotoxin-beta mRNAs were more abundant in sarcoid than in tuberculous granulomas, whereas IL-8 mRNA was strongly expressed only in tuberculous lymph nodes. Strong expression of GM-CSF, TNF-alpha, and IL-8 by granulomas was shown to be correlated, respectively, with the presence of florid granulomatous lesions, the absence of central necrosis, and the presence of neutrophil infiltration. These results demonstrate that the formation of tuberculous and sarcoid granulomas in humans is associated with the expression of characteristic cytokine profiles and indicate that the expression of certain cytokines is associated with the development of specific pathologic features in the resulting granulomas.

Cytokine patterns in tuberculous and sarcoid granulomas: correlations with histopathologic features of the granulomatous response

Cytokines play an important role in granuloma formation, but the extent that cytokine profiles are similar in different granulomatous diseases and whether differences in the histopathologic features of the granulomatous response results from differences in cytokine production have not been evaluated. To investigate these questions, we used RT-PCR to quantify the expression of mRNAs coding for 16 cytokines in granulomatous lymph nodes from patients with tuberculosis and sarcoidosis and from control tissues, and we sought correlations between the level of expression of these cytokines and the histopathologic features of the granulomas. Expression of mRNAs coding for a number of cytokines (IL-1beta, IFN-gamma, TNF-alpha, granulocyte-macrophage (GM)-CSF, IL-12 (p40), and lymphotoxin-beta) was increased in tuberculous and sarcoid granulomas compared with that of control tissues. All sarcoid granulomas were shown to express a Th1 pattern of cytokine mRNAs, while tuberculous lymph nodes expressed either a Th1 or a Th0 profile. GM-CSF and lymphotoxin-beta mRNAs were more abundant in sarcoid than in tuberculous granulomas, whereas IL-8 mRNA was strongly expressed only in tuberculous lymph nodes. Strong expression of GM-CSF, TNF-alpha, and IL-8 by granulomas was shown to be correlated, respectively, with the presence of florid granulomatous lesions, the absence of central necrosis, and the presence of neutrophil infiltration. These results demonstrate that the formation of tuberculous and sarcoid granulomas in humans is associated with the expression of characteristic cytokine profiles and indicate that the expression of certain cytokines is associated with the development of specific pathologic features in the resulting granulomas.

Absence of DNA from mycobacteria of the M. tuberculosis complex in sarcoidosis

To evaluate the role of mycobacterial infection in the pathogenesis of sarcoidosis, several groups have attempted to identify mycobacterial DNA in clinical samples from these patients by polymerase chain reaction (PCR), but widely divergent results have been obtained. It has been suggested that differences in the sensitivity of the procedures used may explain these discrepant results. To test this possibility, the presence of mycobacterial DNA was sought in biopsies from patients with sarcoidosis using sequence capture-PCR, a procedure that is 100-fold more sensitive in detecting mycobacterial DNA in paucibacillary samples than standard PCR protocols. Using this approach, DNA corresponding to two different sequences specific for organisms of the Mycobacterium tuberculosis complex (the 1S6110 insertion element and the DR region) could not be detected in any of the 15 biopsies from patients with sarcoidosis, whereas a high proportion of positive results was obtained for tissue biopsies and other clinical samples from patients with active tuberculosis, including samples that were smear-negative/culture-positive and smear-negative/culture-negative. These results support prior studies suggesting that M. tuberculosis does not play a pathogenic role in sarcoidosis in most patients.