Increased elastin content and decreased elastin concentration may be predisposing factors in dissecting aneurysms of human thoracic aorta.

OBJECTIVE: The aim was to investigate whether changes in elastin distribution in the thoracic aorta are associated with occurrence of dissecting aneurysms. METHODS: Ten thoracic aortas were obtained at necropsy from dissections (mean patient age 74.3 years, SD 7.3) and from 10 age matched controls (mean age 73.1 years, SD 6.9). Full wall thickness samples (1 cm diameter) were taken at 12 sites between heart and diaphragm from aortas of dissections and controls. Elastin content (total elastin per sample), concentration (mg.mg-1 tissue dry weight), degree of cross linking, and amino acid composition were determined. RESULTS: Comparison of areas of dissected aortas involved in dissection with corresponding areas of controls showed significant increases in content of elastin (p < 0.05), content and concentration of proteins other than elastin and collagen (p < 0.01), and a decrease in elastin concentration (p < 0.01). Comparison of areas remote from dissection with corresponding areas in controls showed no significant differences except for decreased elastin concentration (p < 0.05). There were no differences in elastin cross linking. Elastin from dissected aortas had a higher content of aspartate, threonine, serine, glutamate, and lysine and a lower content of glycine, alanine, and valine than elastin from controls (p < 0.05). CONCLUSIONS: Biochemical changes in dissections are localised to the dissected area, with increased deposition of elastin, collagen, and other proteins. The altered matrix composition is likely to change the mechanical properties, possibly increasing the tendency to rupture.

Biochemical investigation of possible lesions in human aorta that predispose to dissecting aneurysms: pyridinoline crosslinks.

Pyridinoline, a collagen specific covalent crosslink, was quantified in acid hydrolysates of human aorta using a non-equilibrium inhibition ELISA. The study was based on specimens from seven cases of aortic dissection and from seven control subjects whose death was unrelated to thoracic aortic dissection. There were no significant differences in the amounts or concentrations of pyridinoline in aortas with dissecting aneurysms compared with normal tissue, thus excluding the possibility of a causative relation between the degree of pyridinoline crosslinking of collagen molecules and dissection of the thoracic aorta. In all cases, however, the number of pyridinoline crosslinks per molecule of collagen in the ascending aorta and arch approached the theoretical maximum for lysyl derivatives and was as high as that present in cartilage. Thus in this region of the vessel pyridinoline represents the major stabilising crosslink of collagen. In contrast, the number of pyridinoline crosslinks per collagen molecule decreased maximally by a factor of 10 between the arch and the proximal regions of the descending thoracic aorta. This suggests a possible correlation between the rigidity of collagen fibres and the forces exerted on the aortic wall during diastole and systole.

TNF alpha mRNA and protein in cardiac transplant biopsies: comparison with serum TNF alpha levels.

OBJECTIVES: To examine the role of TNF alpha (TNF alpha) in cardiac transplant rejection by simultaneous analysis of protein expression and its messenger RNA within serum and grafted tissue. METHODS: 54 endomyocardial biopsy specimens were taken from 19 patients at various times after transplantation. TNF alpha messenger RNA was localised using a digoxygenin labelled complementary DNA probe. An anti-TNF alpha antibody was used to immunohistochemically label the protein product. Serum TNF alpha levels at the time of biopsy were analysed using a specific enzyme-linked immunosorbent assay. RESULTS: TNF alpha mRNA was present in 22/34 endomyocardial biopsies. Eight also contained TNF alpha protein. None had protein alone. Expression did not relate to the grade of rejection in the present or subsequent biopsies. Serum TNF alpha was undetectable (assay sensitivity 30-330 pg/ml) for the majority of specimens. In the nine cases with elevated serum levels, eight samples were from cases within the first 30 days post transplant (r = -0.379; P < 0.05). CONCLUSIONS: Neither tissue TNF alpha mRNA, tissue protein, nor serum TNF alpha relate to the grade of rejection. Furthermore, TNF alpha expression within endomyocardial biopsies is not reflected in the serum. These findings argue against the use of serum analysis as an indicator of cytokine profiles within cardiac tissue allografts. The demonstration of a trend in the early expression of TNF alpha after transplantation suggests that its release may not be specific to the process of rejection.

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.

Rejection in heart transplantation strongly correlates with HLA-DR antigen mismatch.

It is well established that incompatible HLA antigens presented by donor tissue readily evoke an immune response. Prospective HLA matching policies, widespread in European kidney transplant centers have reduced the level of HLA mismatching and have significantly improved graft survival. The influence of HLA incompatibility in heart transplantation remains controversial, and prospective HLA matching is seldom achieved. We examined the role of HLA antigen mismatching on transplant rejection by analyzing 2569 endomyocardial biopsies (EMB) from 157 consecutive orthotopic heart transplants performed from April 1987 to August 1993 in our own center. Biopsies were graded according to the accepted International Classification, with grade 2 and higher indicating rejection. Among 91 patients who received a 2 HLA-DR mismatch transplant 34% of 1624 biopsies analyzed were graded as > or = 2. This frequency fell to 29% of 797 biopsies for 53 patients with a one-HLA-DR mismatch and to 18% of 148 biopsies for 13 patients in the zero-HLA-DR-mismatch group (P < 0.00005). No significant effect on EMB grade frequencies was observed using the same method of analysis with transplants mismatched at the HLA-A or HLA-B loci apart from analysis of HLA-B matched transplants at 3 months posttransplant (P = 0.02). The close linkage of the HLA-B and HLA-DR loci may account for this observation. The results of this study show that heart transplants matched at the HLA-DR locus have a significantly reduced incidence of EMB grades indicative of rejection requiring augmented immunosuppressive therapy. We propose that prospective HLA-DR matching should be adopted for allocation of donor hearts for more efficient use of this precious and limited resource.

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.

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.

Pulmonary diffusion abnormalities in heart transplant recipients. Relationship to cytomegalovirus infection.

Lung function of patients with heart failure is characterized by a variety of changes proposed as being due to passive congestion, secondary pulmonary fibrosis, and/or recurrent pulmonary emboli. A diffusion impairment thought to be due to cyclosporine has also been noted in patients following heart transplantation. Similar changes of unclear origin have been observed in renal transplant recipients. The objective of this study was to determine the extent to which lung function changes are reversible by cardiac transplantation and relate changes to the status of the recipients lung in the presence of possible vascular, iatrogenic, immune, or infectious injury. We analyzed the data of 22 patients who underwent lung function testing before and after heart transplantation and correlated changes to hemodynamic change, episodes of rejection, concentration of cyclosporine, and cytomegalovirus infection. Despite excellent graft function, the carbon monoxide transfer factor deteriorated to a mean of 57 percent of predicted postoperatively. The fall in diffusion factor did not correlate with episodes of cardiac rejection, cyclosporine levels, or hemodynamic status. In those patients who had serologic evidence of cytomegalovirus infection, the reduction in transfer factor was greater compared to those without infection despite a normal chest radiograph. The effects of cardiopulmonary bypass were unlikely to have been responsible for the abnormalities as lung function was assessed at a mean of 14 months after surgery. In heart transplant recipients, a change in diffusion capacity may represent an additional marker for cytomegalovirus infection and reflect infectious/immune injury late following surgery.

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.

Interleukin-10 in human heart transplantation: an in situ hybridization study. The Manchester Transplant Cytokine Group.

BACKGROUND: The role of interleukin-10 in graft acceptance and rejection was investigated by analysis of its messenger RNA expression within endomyocardial biopsy material from heart transplant recipients. METHODS: Forty-six biopsy specimens were analyzed from 19 patients (16 male, 3 female), with an age range of 15 to 62 years (mean = 47 years). Biopsy specimens were "snap" frozen in liquid nitrogen, and 10-microns thick sections were cut and postfixed in 4% paraformaldehyde. Messenger RNA for interleukin-10 was localized with nonradioactively (digoxigenin) labeled complementary DNA probes and detected immunoenzymatically with an antidigoxigenin polyclonal antibody. The histopathologic diagnosis of rejection was made according to the criteria of the Heart Rejection Study group. RESULTS: Interleukin-10 transcripts were detected in 12 of 36 rejecting biopsy specimens. None of the ten nonrejecting biopsy specimens were positive. Expression within the rejection infiltrate was more prominent in biopsy specimens from milder rejection episodes. By contrast, in biopsy specimens from moderate rejection, expression was mainly within areas of fibrosis. The expression of interleukin-10 transcripts did not relate to the number of previous rejection episodes nor to the histologic grade of the subsequent biopsy specimens. CONCLUSIONS: This study emphasizes the importance of in situ techniques in localizing cytokine expression in relation to tissue structure and suggests that interleukin-10 may serve a function in the immune regulation of the infiltrate at sites of inflammation, rather than in immune suppression of the rejection process. Further study is necessary to elucidate the precise role of interleukin-10 in transplantation in relation to the overall profile of cytokine expression within the rejection infiltrate.

RANTES chemokine expression is related to acute cardiac cellular rejection and infiltration by CD45RO T-lymphocytes and macrophages.

BACKGROUND: Despite the advances made in immunosuppression therapy, episodes of acute cellular rejection may affect graft function and survival. We investigated the role of RANTES in cellular recruitment and in cardiac allograft rejection. METHODS: Endomyocardial biopsies (n = 65) from 30 patients were taken at various times after transplantation. In 4 subjects who died of acute cellular rejection, the profile of RANTES expression was monitored in all biopsy specimens and in postmortem tissue. Myocardial tissue from 10 other transplants was also analyzed. Sections were stained with an anti-human RANTES antibody with the streptavidin-biotin technique. RANTES-positive cells were related to macrophage, CD45RO "memory" T-cell, and eosinophil infiltration. RESULTS: RANTES-positive cells were identified within the cellular infiltrate in 95% of biopsies with moderate/severe rejection and 28% with mild rejection. RANTES-positive, CD45RO-positive, and macrophage cell numbers were higher in subjects who died of acute cellular rejection than of other causes. A highly significant difference in RANTES-positive cell number was observed between moderate/severe, mild, and nonrejection groups (p = .0001) and correlated significantly with macrophage number in both right and left ventricles (r = .693, p < .01; r = .599, p < .05, respectively) and with the number of "memory" T cells (r = .829, p < .001; r = .779, p < .01, respectively). CONCLUSIONS: These findings suggest that local release of RANTES is important in the recruitment of both macrophages and CD45RO T cells in cardiac allograft rejection. RANTES may be an important chemokine to target for therapeutic intervention in heart rejection.

Transforming growth factor-beta (TGF-beta1) genotype and lung allograft fibrosis.

BACKGROUND: TGF-beta1 is a prosclerotic cytokine implicated in fibrotic processes. Fibrosis of the pulmonary parenchyma and airways is a frequent presentation in lung transplant recipients before and after transplantation. There are two genetic polymorphisms in the DNA sequence encoding the leader sequence of the TGF-beta1 protein, located at codon 10 (either leucine or proline) and at codon 25 (either arginine or proline). The codon 25 arginine allele is associated with higher TGF-beta1 production by cells activated in vitro. We tested the hypothesis that inheritance of alleles of the TGF-beta1 gene conferring higher production of TGF-beta1 may be responsible for over-expression of TGF-beta1 in transplant recipients resulting in lung allograft fibrosis. METHODS: We extracted DNA from leukocytes collected from 91 pulmonary transplants performed at our centre and 96 normal healthy volunteers between May 1990 and September 1995. Part of the first exon was amplified by PCR. Samples were genotyped by using sequence specific oligonucleotide probes. RESULT: The distribution of codon 10 alleles was similar in a normal healthy control group and in lung transplant recipients, regardless of their pretransplant lung pathology. By contrast, there was a significant difference in the frequency of codon 25 alleles between the control and transplant groups. In the normal control group 81% were codon 25 arginine/arginine (A/A) homozygotes, 19% were arginine/proline (A/P) heterozygotes and none were proline/proline (P/P) homozygotes. The distribution of codon 25 alleles was similar in lung transplant recipients who did not have a significant fibrosis in pretransplant pathology, but in transplant recipients who came to transplantation with lung fibrosis 98% (41 of 42 patients) were homozygous for the codon 25 A/A allele (p < .05). After lung transplantation 39 of 91 patients developed lung allograft fibrosis, and of these 92.3% (36 of 39 recipients) were of homozygous codon 25 A/A high TGF-beta1 producer genotype (p < .001). Lung transplant recipients who were homozygous for both codon 10 L/L and codon 25 A/A showed poor survival compared with all other TGF-beta1 genotypes (p < .03). CONCLUSION: Homozygosity for arginine at codon 25 of the leader sequence of TGF-beta1 that correlates with higher TGF-b production in vitro, is associated with fibrotic lung pathology before lung transplantation and with the development of fibrosis in the graft. In combination with the codon 10 leucine allele, homozygosity for the codon 25arginine allele is a marker for poor post-transplant prognosis and recipient survival.

Nuclear diameter in parathyroid disease.

The nuclear diameter of chief cells was measured in 17 cases of parathyroid adenomas, four cases of secondary hyperplasia, five cases of primary hyperplasia and six cases of tertiary hyperparathyroidism. All the cases with secondary hyperplasia and tertiary hyperparathyroidism were associated with chronic renal failure. The nuclear diameter in both the adenomatous and hyperplastic areas of tertiary hyperparathyroidism were measured. The adenomatous areas of tertiary hyperparathyroidism contained nuclei of a larger diameter than those in the hyperplastic foci of the same gland. The nuclear diameter in adenomatous foci of tertiary hyperparathyroidism was similar to that in adenomas from primary hyperparathyroidism. These findings lend support to the concept of formation of autonomous adenomas against a background of reactive parathyroid hyperplasia in cases of tertiary hyperparathyroidism. Using statistical methods there were differences between the nuclear diameter in cases of primary adenomata, and cases of primary and secondary hyperplasia. Primary parathyroid hyperplasia stood out as a distinct group. The significance of these findings is discussed.

Immunoblastic lymphadenopathy: evolution into immunoblastic sarcoma.

A case of immunoblastic lymphadenopathy which underwent transformation into immunoblastic sarcoma is reported. A 64-year-old man presented with a rash, generalised lymphadenopathy, and hepatosplenomegaly. A cervical lymph node removed at biopsy showed the features of immunoblastic lymphadenopathy with the presence of heavy chain classes IgG, IgM, and IgA and both kappa and lambda light chain types in the cytoplasm of the immunoblasts. No such immunoglobulins could be demonstrated in the lymph nodes obtained at necropsy when the patient died of widespread immunoblastic sarcoma. The biological evolution and histogenesis of the disease are discussed and the current literature is reviewed.

Effect of oxygen on the lungs after blast injury and burns.

In March 1979 there was an explosion in a coalmine in Lancashire. As a result three men were found dead down the mine and a further seven men, all with extensive burns, died between the third and thirteenth day after the explosion. The lungs were studied in all the cases. Pulmonary infection was the commonest cause of death. Despite high levels of oxygen being given to these seven men, only one case showed a focal intra-alveolar fibrosis. In this case the inspired oxygen requirement came down before death. The toxicity of oxygen in the short term management of patients with severe trauma is questioned.

Pneumocystis carinii pneumonia: a light microscopical and ultrastructural study.

A case of Pneumocystis carinii pneumonia developing a patient with treated diffuse lymphocytic lymphoma is described. The electron microscopic features and life cycle of the organism are illustrated. The patient died twenty-four hours after the biopsy had been taken. Septrin appeared to have affected the trophozoite stage. Pneumocystis carinii appears to induce interstitial pulmonary oedema and fibrosis. A discussion of the role of electron microscopy in early diagnosis of the disease is presented.

Prealbumin in the diagnosis of bronchopulmonary carcinoid tumours.

The reliability of prealbumin as a diagnostic marker was studied in 60 cases of bronchopulmonary carcinoid tumours. There were differences in the incidence of positivity between typical and atypical carcinoids (well differentiated neuroendocrine carcinomas). Seventy five per cent of the carcinoid tumours were positive for prealbumin; (86.7% typical and 63.3% atypical carcinoids). In 15 cases, which were Grimelius negative, 10 were prealbumin positive. Only 8.3% carcinoids were negative with both prealbumin and Grimelius stains. Ten squamous, 10 adeno- and 10 small cell carcinomas showed only occasional scattered prealbumin positive cells. It is concluded that prealbumin is a useful marker for bronchopulmonary carcinoid tumours. It is cheap, readily available, and should be considered part of routine diagnostic procedures for the diagnosis of carcinoid tumours.

Desmoplastic malignant mesothelioma: a review of 17 cases.

AIMS: To identify the histological features of desmoplastic mesothelioma, and to determine its incidence and prognosis. METHODS: Two hundred and fifty five cases of malignant mesothelioma were examined over seven years (1982-9) to identify the desmoplastic variant. Sections were cut at 5 microns and stained with haemotoxylin and eosin and with CAM 5.2 (Dakopatts). Asbestos fibre counts were carried out by light microscopy in 14 cases using the potash digestion method. RESULTS: Seventeen cases were identified as desmoplastic mesothelioma giving an incidence of 6.6%. In 11 cases the cell type in more cellular areas was sarcomatous and in six others it was biphasic. The mean survival time from onset of symptoms to death was 5.8 months for the sarcomatous variant and 6.8 months for the biphasic variant. Twelve of 16 patients had had previous occupational exposure to asbestos, ranging from five months to 43 years. The diagnosis of desmoplastic mesothelioma was only accepted if acellular connective tissue comprised 50% or more of the tumour bulk. Also seen was collagen necrosis, anastomosing bands of often hyalinised collagen with a prominent storiform pattern, and where cellular detail was present there were hyperchromatic nuclei. CONCLUSIONS: Desmoplastic mesothelioma is a rare variant of malignant mesothelioma with a storiform collagen pattern, collagen necrosis, bland acellular collagen and focal cytological features of malignancy. Though rare, it is important to recognise this variant and distinguish it from a pleural plaque, nonspecific reactive pleural fibrosis, pleurisy, rheumatoid disease, or, rarely, spindle cell sarcomas.

Lack of C-erbB-2 protein expression in pulmonary carcinoid tumours.

To determine if amplification of the C-erb-B2 proto-oncogene could be correlated with prognosis in carcinoid tumours, 49 pulmonary carcinoid tumours (26 typical, 23 atypical) were examined using a polyclonal antibody to the C-terminal peptide of the C-erb-B2 protein sequence. No C-erb-B2 gene product could be shown: the demonstration of C-erb-B2 does not seem to help, therefore, in determining diagnosis or prognosis in pulmonary carcinoid tumours.