Survey of British pathologists' performance of mesothelioma post-mortems.

We analyzed the practice of mesothelioma post-mortems in the United Kingdom (UK). Between 2003 and 2004, a questionnaire was sent to all UK Consultant Histopathologists, and 12% were recruited. In general post-mortems, the Coroner approved 60% of requests for organ retention, and Pathologists failed to make such a request in 5.9% of cases. In asbestos cases, the lungs were not fixed for sampling in 54.8% of cases, owing to the Coroners' refusal in 46.4% and the pathologists' failure to make a request in 8.4% of cases. In epithelioid mesothelioma, mesothelial and epithelial stains were considered to be of similar importance, and calretinin was the most popular individual stain. In sarcomatoid mesothelioma, mesothelial stains were chosen by 45.9% of pathologists, cytokeratin by 18.7% and epithelial stains by 18.5%. Calretinin was the most popular stain. Accurate mesothelioma diagnosis is impeded by the lack of tissue being made available by the Coroner and failure of some pathologists to make requests. Pathologists use appropriate immunohistochemical testing in epithelioid mesothelioma. In sarcomatoid mesothelioma, epithelioid stains were popular but have limited use. The Coroner should approve more requests for organ retention, and information should be disseminated to pathologists regarding best practice in mesothelioma.

Sensitivity and specificity of immunohistochemical markers used in the diagnosis of epithelioid mesothelioma: a detailed systematic analysis using published data.

AIMS: Immunohistochemistry is frequently employed to aid the distinction between mesothelioma and pulmonary adenocarcinoma metastatic to the pleura, but there is uncertainty as to which antibodies are most useful. We analysed published data in order to establish sensitivity and specificity of antibodies used to distinguish between these tumours with a view to defining the most appropriate immunohistochemical panel to use when faced with this diagnostic problem. METHODS AND RESULTS: A systematic analysis of the results of 88 published papers comparing immunohistochemical staining of a panel of antibodies in mesothelioma with epithelioid areas, and pulmonary adenocarcinoma metastatic to the pleura. Results for a total of 15 antibodies were analysed and expressed in terms of sensitivity and specificity. The most sensitive antibodies for identifying pulmonary adenocarcinoma were MOC-31 and BG8 (both 93%), whilst the most specific were monoclonal CEA (97%) and TTF-1 (100%). The most sensitive antibodies to identify epithelioid mesothelioma were CK5/6 (83%) and HBME-1 (85%). The most specific antibodies were CK5/6 (85%) and WT1 (96%). CONCLUSIONS: No single antibody is able to differentiate reliably between these two tumours. The use of a small panel of antibodies with a high combined sensitivity and specificity is recommended.

Discrepancies between clinical and autopsy diagnosis and the value of post mortem histology; a meta-analysis and review.

The autopsy is in decline, despite the fact that accurate mortality statistics remain essential for public health and health service planning. The falling autopsy rate combined with the Coroners Review and Human Tissue Act have contributed to this decline, and to a falling use of autopsy histology, with potential impact on clinical audit and mortality statistics. At a time when the need for reform and improvement in the death certification process is so prominent, we felt it important to assess the value of the autopsy and autopsy histology. We carried out a meta-analysis of discrepancies between clinical and autopsy diagnoses and the contribution of autopsy histology. There has been little improvement in the overall rate of discrepancies between the 1960s and the present. At least a third of death certificates are likely to be incorrect and 50% of autopsies produce findings unsuspected before death. In addition, the cases which give rise to discrepancies cannot be identified prior to autopsy. Over 20% of clinically unexpected autopsy findings, including 5% of major findings, can be correctly diagnosed only by histological examination. Although the autopsy and particularly autopsy histology are being undermined, they are still the most accurate method of determining the cause of death and auditing accuracy of clinical diagnosis, diagnostic tests and death certification.

Neuroendocrine differentiation in non-small cell lung cancer and its relation to prognosis and therapy.

AIMS: Histopathologists report the presence of neuroendocrine (NE) differentiation in non-small cell lung carcinoma (NSCLC) in up to a third of cases and are often questioned about its clinical relevance. The conclusions of previous studies have been inconsistent. This paper aims to provide an answer by examining a large series together with a comprehensive critique of the literature. METHODS AND RESULTS: Four hundred and thirty-nine cases of NSCLC were examined, immunohistochemically, using antibodies to chromogranin A (CGA), synaptophysin (SYN) and CD56/neural cell adhesion molecule (NCAM). Three hundred and forty-one cases had been treated with surgical resection and the remainder with chemotherapy. The results were compared with clinical outcome. Thity-six percent of cases had positive staining for at least one NE marker. CGA was positive in 5.5% of cases, SYN in 16.5% and NCAM in 28%. There was no association between the presence of NE markers and survival in either the surgically treated group or the chemotherapy-treated group. There was also no association between NE markers and response to chemotherapy in the latter group. CONCLUSIONS: The presence of immunohistochemically detected NE differentiation in NSCLC is not of prognostic significance.

The distribution of cardiac macrophages in myocardial ischaemia and cardiomyopathy.

AIMS: Recent evidence has implicated the macrophage as an effector cell in the inflammatory processes in transplant rejection, as well as cardiac disease, including coronary atherosclerosis. Although the latter is a vascular disease, the entire myocardium is affected. We have previously demonstrated the presence and distribution of macrophages in the 'normal' human heart. In this paper the distribution of myocardial macrophages, in the various chambers of the failing human heart, from cases of coronary atheroma and cardiomyopathy undergoing heart transplantation is documented. METHODS AND RESULTS: Tissue blocks were removed at specific sites taken from six cases with ischaemic heart disease (IHD) (four males, two females, age range 54-62 years), and four cases with idiopathic dilated cardiomyopathy (IDCM) (three males, one female, age range 18-49 years). These were compared with hearts from five cases of sudden death, unrelated to heart disease. Sections were stained with a CD68 pan macrophage marker. Positive cells were enumerated in 20 random fields. Results were analysed using a generalized linear modelling method using a Poisson distribution. Macrophages were identified within the interstitium and often close to blood vessels in all hearts. Macrophages from IHD hearts demonstrated the most intense staining and were often larger and more elongated than those found in 'normal' control hearts. Macrophages were also often degranulated and staining was diffuse in the interstitium. Overall, there were significantly more macrophages in most areas from IHD hearts than from IDCM hearts or control hearts (P < 0.001). CONCLUSIONS: Significantly more macrophages were found in all four chambers in diseased hearts compared with controls. Macrophage numbers were higher in the atria than in ventricles in the diseased myocardium. This study suggests selective recruitment of macrophages into the atria in the disease states studied.

Inter-observer variation between pathologists in diffuse parenchymal lung disease.

BACKGROUND: There have been few inter-observer studies of diffuse parenchymal lung disease (DPLD), but the recent ATS/ERS consensus classification provides a basis for such a study. METHODS: A method for categorising numerically the percentage likelihood of these differential diagnoses was developed, and the diagnostic confidence of pathologists using this classification and the reproducibility of their diagnoses were assessed. RESULTS: The overall kappa coefficient of agreement for the first choice diagnosis was 0.38 (n = 133 biopsies), increasing to 0.43 for patients (n = 83) with multiple biopsies. Weighted kappa coefficients of agreement, quantifying the level of probability of individual diagnoses, were moderate to good (mean 0.58, range 0.40-0.75). However, in 18% of biopsy specimens the diagnosis was given with low confidence. Over 50% of inter-observer variation related to the diagnosis of non-specific interstitial pneumonia and, in particular, its distinction from usual interstitial pneumonia. CONCLUSION: These results show that the ATS/ERS classification can be applied reproducibly by pathologists who evaluate DPLD routinely, and support the practice of taking multiple biopsy specimens.

Angiogenic cytokines in patients with idiopathic interstitial pneumonia.

BACKGROUND: Angiogenesis has been implicated in the pathogenesis of idiopathic interstitial pneumonia (IIP). The aim of this study was to examine the relationship between plasma concentrations of the angiogenic cytokines interleukin 8 (IL-8), vascular endothelial growth factor (VEGF), and endothelin-1 (ET-1) and clinical parameters of disease progression over a 6 month period to identify potential aetiological mediators and prognostic markers of disease activity in patients with IIP. METHODS: Forty nine patients with IIP (40 men) were recruited to the study. Plasma cytokine measurements, pulmonary function tests, and high resolution computed tomography (HRCT) scans were performed on recruitment and after 6 months. Plasma cytokine measurements were also performed in 15 healthy volunteers for control purposes. RESULTS: Patients with IIP had significantly higher median (IQR) baseline concentrations of IL-8 and ET-1 than controls (155 (77-303) pg/ml v 31 (0-100) pg/ml, p<0.001) and (1.21 (0.91-1.88) pg/ml v 0.84 (0.67-1.13) pg/ml, p<0.01), respectively. Baseline concentrations of IL-8, ET-1, and VEGF were significantly related to the baseline HRCT fibrosis score (r = 0.42, p<0.005; r = 0.39, p<0.01; and r = 0.42, p<0.005, respectively). Patients with IIP who developed progressive disease had significantly higher baseline levels of IL-8 (345 (270-497) pg/ml v 121 (73-266) pg/ml, p = 0.001) and VEGF (1048 (666-2149) pg/ml v 658 (438-837) pg/ml, p = 0.019). Over 6 months the change in VEGF was significantly related to the change in HRCT fibrosis score (r = 0.565, p = 0.035) and negatively related to the change in forced vital capacity (r = -0.353, p = 0.035).

Murine gammaherpes virus as a cofactor in the development of pulmonary fibrosis in bleomycin resistant mice.

Studies of human tissue have suggested an association between productive Epstein Barr virus and idiopathic pulmonary fibrosis (IPF). However, a pathogenic role for the virus has not been established. This study was undertaken to develop an animal model, which would explore the association between viral infection and pulmonary fibrosis. BALB/c mice (n=30), resistant to bleomycin, were primed with murine gammaherpesvirus 68 and then given intraperitoneal bleomycin. The mice were sacrificed at 28 days after bleomycin and their lungs assessed histologically and biochemically. Lung pathology was scored 0-3 for fibrotic and inflammatory change. BALB/c mice given virus and bleomycin showed more lung fibrosis (median score 2.2) compared to those given bleomycin alone (median 0), virus alone (median 0.2) or phosphate-buffered saline (PBS) control (median 0). Similarly mice given both virus and bleomycin showed more lung inflammation (median score 1.9) compared to those given bleomycin (median 0.5), virus (median 0.8), or PBS control (median 0.2). There was a significant difference in collagen content between the bleomycin and virus group (mean 1.86 mg) compared to the belomycin alone group (mean 1.52 mg). These results suggest that virus alone does not result in pulmonary fibrosis but that replicating virus in the presence of an exogenous injury may promote the development of pulmonary fibrosis.

The rapamycin analogue SDZ RAD attenuates bleomycin-induced pulmonary fibrosis in rats.

Pulmonary fibrosis is characterized by excessive deposition of extracellular matrix proteins within the pulmonary interstitium. The new macrolide immunosuppressant SDZ RAD, a rapamycin analogue, inhibits growth-factor dependent proliferation of mesenchymal cells and might therefore be of therapeutic interest for the treatment of fibrotic lung disease. In this study the effect of SDZ RAD on lung-collagen accumulation in the bleomycin model of pulmonary fibrosis in rats was investigated. SDZ RAD (2.5 mg x kg(-1) x day(-1)) or drug vehicle were administered orally by daily gavage. Successful dosing was confirmed by measuring splenic weight. Total lung-collagen content was measured by high-performance liquid chromatographic quantitation of hydroxyproline. In animals given bleomycin and drug vehicle, total lung collagen was increased by 182+/-11% (mean+/-SEM) compared with saline controls at 14 days (p<0.001). The increase in lung-collagen accumulation was reduced by 75+/-12% (p<0.01) in animals given SDZ RAD and was accompanied by a concomitant 56+/-6% (p<0.001) reduction in lung weight. SDZ RAD is currently in clinical trials for the prevention of solid organ graft rejection, another condition characterized by excessive extracellular matrix production. The authors propose that SDZ RAD warrants evaluation as a novel therapeutic agent for fibrotic lung disease.

Epstein-Barr virus and wild p53 in idiopathic pulmonary fibrosis.

Both Epstein-Barr virus (EBV) and p53 have independently been associated with idiopathic pulmonary fibrosis (IPF). This study explores further whether a relationship potentially exists between EBV and p53 in IPF, thereby providing a possible mechanism for the role of EBV in the disease progression of IPF. Lung tissue from open lung biopsies of 14 IPF patients was compared with a control group of 19 patients. EBV status was determined using both immunohistochemistry and PCR, while p53 expression was assessed with immunohistochemistry Seven of 14 IPF patients expressed p53 compared to one of 19 control subjects (P = 0.011). Eight IPF patients and no controls were positive for EBV (P < 0.01). Four IPF patients demonstrated both EBVand p53 expression compared with no controls, (P = 0.05). This study suggests that a relationship between EBV and p53 may exist in patients with IPF.

Tumor necrosis factor-alpha gene polymorphism and death due to acute cellular rejection in a subgroup of heart transplant recipients.

Irreversible acute rejection of the transplanted heart usually has a fatal outcome. Predicting which recipients are most likely to reject might allow closer monitoring and modification of treatment protocols to prevent graft loss. Recipients genetically predisposed to produce more TNF-alpha are those who suffer the most acute rejection episodes. Here we show that TNF-alpha genotype is strongly associated with death due to acute cell-mediated heart transplant rejection (Chi-square = 28.57, p < 0.0001). This subgroup of recipients should be given optimally tissue matched transplants and should be treated with the most effective immunosuppressive regimens.

Bone histomorphometry in adult patients with cystic fibrosis.

STUDY OBJECTIVE: Low bone mineral density is a common complication of cystic fibrosis (CF), and recent studies have implicated vitamin D insufficiency as a significant etiologic factor. The aim of this study was to establish whether there was bone biopsy evidence of vitamin D deficiency osteomalacia in patients with CF and to document the general histomorphometric characteristics of CF bone. PATIENTS AND METHODS: A retrospective descriptive and histomorphometric study of postmortem L2/L3 vertebral bone biopsy specimens was undertaken on tissue from 11 posttransplant CF patients and 4 nontransplanted CF patients. Control data were derived from postmortem bone specimens from 15 young adults. RESULTS: Bone from all CF patients was characterized by severe osteopenia in both trabecular and cortical bone. At the cellular level, there was decreased osteoblastic and increased osteoclastic activity. The reduction in osteoblastic activity was due to both a decrease in osteoblast number and a decrease in the biosynthetic potential of osteoblasts. The osteoclastic changes were due to an increase in the number of osteoclasts. The increase in osteoclasis and the uncoupling of osteoblastic and osteoclastic activity resulted in an increase in resorptive surfaces. Although there were few significant differences between the transplanted and nontransplanted CF groups, both cortical and trabecular bone mass tended to be lower after transplantation. None of the CF undecalcified biopsy specimens showed osteoid parameters characteristic of vitamin D deficiency osteomalacia. CONCLUSIONS: CF patients have an unusual and complex pattern of cellular changes within bone that are not typical of vitamin D deficiency osteomalacia.

Immunoreactivity for cadherins, HGF/SF, met, and erbB-2 in pleural malignant mesotheliomas.

AIMS: To assess the immunoreactivity of malignant mesotheliomas for N- and E-cadherins, hepatocyte growth factor/scatter factor (HGF/SF) and the tyrosine kinase receptors, met and erbB-2. METHODS AND RESULTS: Pleural malignant mesotheliomas were stained using a standard indirect immunoperoxidase method applied to paraffin sections. Malignant mesotheliomas were immunoreactive for N-cadherin (26/29; 90%), met (29/29; 100%) and erbB-2 (28/29; 97%). Focal immunoreactivity was present for E-cadherin in epithelioid or mixed tumours (14/25; 56%), and for HGF/SF (9/24; 38%). CONCLUSIONS: Expression of N-cadherin supports the diagnosis of malignant mesothelioma and use of appropriate antibodies would be a useful addition to a diagnostic antibody panel. Focal staining for E-cadherin does not exclude mesothelioma. Signalling pathways mediated via met and erbB-2 may play a role in the growth and spread of malignant mesotheliomas.

Mesotheliomas with deciduoid morphology: a morphologic spectrum and a variant not confined to young females.

Deciduoid mesotheliomas are rare with only four previously reported cases, all affecting the peritoneum of young females. We describe another six cases (three men and three women; age range 52-65 yrs, median 55 yrs; five peritoneal and one pleural). Three patients had an occupational history of asbestos exposure. The deciduoid appearance predominated in four cases, whereas in two it represented a minor component within conventional tubulopapillary epithelioid mesothelioma. All tumors were strongly cytokeratin-positive (including CK5/6) and all showed at least focal staining for thrombomodulin, HBME-1, and calretinin. All were negative for epithelial mucin (D/PAS), CEA, BerEP4, LeuM1 (CD15), CD21, CD35, and S100 protein. Five of six cases (83%) were vimentin-positive and two (33%) were focally positive for alpha-smooth muscle actin. A differential diagnosis of gastrointestinal autonomic nerve tumor (GANT) had been initially considered from the morphology of one case, and we found positivity for some of the "neuronal" markers described in GANTs. This prompted us to apply such a panel to the other five tumors, accepting that the cytokeratin positivity encountered in all of our cases would exclude GANT. All cases of deciduoid mesothelioma (100%) were positive for PGP 9.5 and NSE and four of six (66%) were positive for NKI/C3. Weak focal staining (<5% cells) for synaptophysin was seen in two of six tumors. All cases were chromogranin-negative. All cases examined by electron microscopy showed desmosomes and smooth microvilli without rootlets but no neuroendocrine granules. In conclusion, a deciduoid morphology appears to be part of the histopathologic spectrum encountered in epithelioid mesothelioma. This variant is not confined to female patients and occurs over a wider age range than previously recognized. The overlapping immunophenotype with GANTs illustrates that caution should be exercised when interpreting positivity for "neuronal" markers in this context. An immunohistochemical panel that includes cytokeratins should always be used.

The influence of histocompatibility on graft rejection and graft survival within a single center population of heart transplant recipients.

BACKGROUND: We report a consecutive single center series of 261 patients who received first orthotopic heart transplants from 1986 to 1997. The 1- and 5-year graft survivals were 78 and 68%. The influence of histocompatibility was investigated by comparing graft survival and numbers of treated rejection episodes with HLA-A, -B, and -DR mismatches over different time periods. FINDINGS: Recipients with six mismatches for HLA-A+-B+-DR combined (13.4%) had reduced survival at 7 years (47%) when compared with other recipients (64%). In the first year of transplant, recipients with four HLA-A+-B mismatches had significantly reduced actuarial graft survival (P=0.03) with the greatest influence apparent at 6 months [0-3 mismatches (n=193) 85% versus 4 mismatches (n=68) 69%; P=0.005, OR=2.1]. For 182 recipients with functioning hearts at 1 year, the number of rejection episodes treated within this time was strongly influenced by HLA-DR mismatch [0 DR mismatch (n=15) mean 1.2 rejection episodes versus 1 DR mismatch (n=76) mean 2.7 rejection episodes versus 2 DR mismatches (n=91) mean 3.8 rejection episodes: P=0.0002]. Of these 182 transplants, recipients who had more than four treated rejection episodes during the first year had a significantly reduced 7- year survival [<5 rejection episodes (n=133) 85% versus more than four rejection episodes (n=49) 66%; P=0.02, OR=3.4], as did those with two HLA-DR mismatches [0+1 mismatch (n=91) 87% versus 2 mismatches (n=91) 70%; P<0.05, OR=2.4]. INTERPRETATION: We show that graft loss in the first 6 months of transplant is significantly influenced by four HLA-A+-B mismatches. HLA-DR mismatch significantly increases the number of rejection episodes within the first year, without influencing graft survival. After 12 months both >4 rejection episodes in the first year and two HLA-DR mismatches are markers for late graft loss. We postulate that immunological graft loss in the first 6 months is dominated by the direct allorecognition pathway driven by HLA-DR mismatch. This mechanism is later lost or suppressed. Our data highlight HLA-DR mismatch as a marker for late graft loss and we show an advantage to avoiding transplanting hearts with six HLA-A+-B+-DR mismatches and to minimizing HLA-DR mismatches whenever possible.

TNF-alpha in acute cardiac transplant rejection.

Acute cardiac allograft rejection is an immune-mediated response, hallmarked by cellular infiltration and myocyte damage in the transplanted heart. Cardiac biopsy sampling has been the 'gold' standard for routinely monitoring episodes of acute rejection. As cardiac biopsy is invasive, attention has focused on other non-invasive methods, such as serum analysis, for monitoring purposes. Tumour necrosis factor alpha (TNF-alpha) is a lymphocyte- and macrophage-derived cytokine that is pleiotropic in its actions. Its proinflammatory functions suggest that it may play an important role in initiating and orchestrating the rejection response. Studies demonstrating a correlation in the expression of TNF-alpha with the severity of the rejection episode have placed TNF-alpha as a prime candidate marker of rejection, and have prompted further study to elucidate these findings. This review discusses the limitations of the methodologies used to identify TNF-alpha, and how intragraft expression of TNF-alpha is not reflected in the serum. Furthermore, we describe how other stimuli besides the rejection response can affect TNF-alpha production, arguing against its use as a 'rejection-specific' marker. Nevertheless, genetic studies suggest that TNF-alpha may influence transplant outcome, and offer a new tool for studying the role of TNF-alpha in acute transplant rejection