Imaging the inflammatory activity of sarcoidosis: sensitivity and inter observer agreement of (67)Ga imaging and (18)F-FDG PET

AIM

The aim of this study was to investigate sensitivity of 67Ga imaging and 18F-FDG PET for sarcoidosis activity and their inter observer variability.

METHODS

Thirty-four newly diagnosed, histologically proven sarcoidosis patients were analyzed prospectively. (67)Ga imaging and (18)F-FDG PET were performed, the presence of pulmonary and extra pulmonary lesions was evaluated and inter observer variability of both techniques was assessed.

RESULTS

Overall sensitivity to detect active sarcoidosis was 88% for (67)Ga imaging and 97% for (18)F-FDG PET. Although these results were not significantly different, 18F-FDG PET detected more lesions in the mediastinum (P<0.05), hila (P<0.05), lymph nodes (P<0.001) and extra pulmonary regions in general (P<0.001). Inter observer agreement was poor to moderate for (67)Ga imaging (kappa 0.19-0.59) and good to very good for (18)F-FDG PET (kappa 0.65-1.00).

CONCLUSION

(18)F-FDG PET is more sensitive than (67)Ga imaging in the assessment of sarcoidosis activity with regard to the mediastinum, hila, lymph nodes and extra pulmonary lesions in general. Furthermore, (18)F-FDG PET demonstrates a very good inter observer agreement in contrast with (67)Ga imaging and (18)F-FDG PET is therefore the nuclear imaging technique of choice in sarcoidosis assessment.

Desquamative interstitial pneumonia, respiratory bronchiolitis and their relationship to smoking

AIMS

Respiratory bronchiolitis (RB) and desquamative interstitial pneumonia (DIP) are closely associated histological patterns of interstitial pneumonia, although there are no studies on the extent of individual histological parameters. Furthermore, the term smoking related-interstitial lung disease (SR-ILD) has been proposed as a term to encompass patients with both these histological patterns who give a history of smoking, though it is not well defined how this term relates to historical cases of DIP. The aim of this study was to compare histological parameters in cases of DIP and RB and then to review in detail clinical, imaging and histological data for DIP in relation to a history of smoking.

METHODS AND RESULTS

Forty-nine cases were reviewed, 24 with RB and 25 with DIP; five cases of DIP were re-classified as RB on review due to bronchocentricity of the infiltrate. There was a significantly greater extent of interstitial fibrosis (P = 0.02), lymphoid follicles (P < 0.001) and eosinophilic infiltration (P < 0.0001) in patients with DIP compared with RB. In addition, the extents of these three parameters were significantly interrelated. Patients with DIP had a lower incidence of smoking (60%) when compared with patients with RB-ILD (93%) (P < 0.005). Further analysis of smokers versus never-smokers with DIP showed no difference in histological parameters, extent of haemosiderin deposition or the number of CD1a+ macrophages between the two groups, nor were there any differences in clinical data to suggest other aetiologies. Follow-up high-resolution computed tomography data from patients with DIP suggested that a pattern of fibrotic non-specific interstitial pneumonia (NSIP) may develop in the long term in both smokers and never-smokers.

CONCLUSION

There are significant differences in the extent of interstitial fibrosis, lymphoid follicles and eosinophilic infiltration between DIP and RB, as well as a much lower incidence of smoking in patients with DIP. Whether the lower reported incidence of smoking in DIP reflects referral bias or conservatism in giving a history of smoking remains uncertain, as neither histological parameters nor clinical data indicate a difference between smokers and never-smokers with DIP. Nevertheless, some cases of DIP are likely to remain idiopathic and unrelated to RB, though still have a good prognosis. Furthermore, they may evolve into a pattern resembling fibrotic NSIP. Therefore, whilst SR-ILD is appropriate in the correct clinical setting, the distinction between the histological patterns of RB and DIP remains appropriate.

Echocardiography and pulmonary function as screening tests for pulmonary arterial hypertension in systemic sclerosis

OBJECTIVE

A prospective study to evaluate echocardiography and gas transfer (DLCO) by comparison with cardiac catheterization in discriminating between patients with and without systemic sclerosis-associated pulmonary arterial hypertension (SScPAH).

METHOD

A total of 137 (52 with and 85 without pulmonary fibrosis) had echocardiography and lung function tests within 3 months of their definitive invasive study.

RESULTS

At cardiac catheterization 99 of these patients were found to have PAH, while PAH was excluded in 38. Echocardiographically estimated tricuspid gradient (TG) showed a moderate positive correlation (r(2) = 0.44, P<0.005) with both mean pulmonary pressure and invasively determined tricuspid gradient. DLCO showed a weak correlation (r(2 )= 0.09, P = 0.006), when compared with mean pulmonary arterial pressure. In total, 97% of patients with an echocardiographically determined TG of > 45 mmHg were found to have pulmonary hypertension at catheterization. However, no threshold could be defined with either screening test that safely excluded PAH.

CONCLUSIONS

The positive predictive accuracy of currently used non-invasive tests are adequate for the diagnosis of advanced PAH provided sufficiently high thresholds (TG > 45 mmHg or DLCO < 55% predicted) are used. These tests cannot be relied upon to exclude pulmonary hypertension where pre-test probability is high.

Increased vitronectin and endothelin-1 in the breath condensate of patients with fibrosing lung disease

BACKGROUND

Non-specific interstitial pneumonia (NSIP) and fibrosing alveolitis associated with systemic sclerosis (FASSc) are diseases of unknown aetiology that are characterised by the accumulation of mononuclear cells, followed by the progressive deposition of collagen within the interstitium and subsequent destruction of lung airspace. Better understanding of mediators involved in fibrosis may be useful for early diagnosis and in clinical monitoring of disease progression.

OBJECTIVE

The aim of this study was to investigate the presence of two profibrotic markers, the vitronectin and the endothelin-1 (ET-1) in the airways of NSIP and FASSc patients.

METHODS

Ten NSIP (6 males, age 57 +/- 2 years) and 15 FASSc (8 males, age 55 +/- 4 years) patients were recruited along with 10 normal subjects (4 male, age 52 +/- 2 years). Vitronectin and ET-1 concentrations were measured in their breath condensate, using a specific enzyme immunoassay.

RESULTS

Higher levels of vitronectin and ET-1 were observed in NSIP and FASSc patients [median 92.8 (91.7-93.9) microg/ml; median 8.3 (7.9-9.3) pg/ml] than in control subjects [median 80.3 (89.3-91.4) microg/ml; p < 0.01; median 5.3 (4.9-5.9) pg/ml, p < 0.0001]. We also found increased concentrations of vitronectin in patients with clinical deterioration compared to those remaining stable and in ex-smokers compared to non-smokers and, increased vitronectin and ET-1 in patients treated with steroids compared to untreated patients.

CONCLUSION

These findings justify further studies of vitronectin and ET-1 levels in exhaled breath condensate, as a means of monitoring activity and predicting progression of pulmonary fibrosis.

Ace gene I/D polymorphism and sarcoidosis pulmonary disease severity

Previous studies of the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene in sarcoidosis have revealed both ethnic heterogeneity of I/D frequencies and controversy surrounding the association between the polymorphism and severity of disease. The objective of this study was, therefore, to clarify the role of the ACE I/D polymorphism in (1) disease susceptibility, (2) pulmonary disease severity (with particular reference to pulmonary fibrosis), and (3) pulmonary disease progression, in two distinct European sarcoidosis populations. Standard chest radiographic staging was performed on 118 UK and 56 Czech white patients with sarcoidosis at 2 yr from presentation. Pulmonary function data were analyzed, and patients were then categorized according to disease severity. A PCR-SSP assay was used to determine the ACE I/D genotype of each patient studied. The I/D allele frequencies from these patients were compared with frequencies from ethnically matched UK (n = 386) and Czech (n = 179) control subjects using a chi-square contingency table. No significant differences were seen in the distribution of the ACE I/D genotypes, allele frequencies or phenotype frequencies. Furthermore, no association was found between the ACE I/D polymorphism and pulmonary disease severity, fibrosis, and progression. We conclude that the ACE I/D polymorphism has no role in sarcoidosis susceptibility in European whites and that it is not a regulatory variant in this disease.

Analysis of tumor necrosis factor-alpha, lymphotoxin-alpha, tumor necrosis factor receptor II, and interleukin-6 polymorphisms in patients with idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is characterized by chronic inflammation that is associated with structural damage of the lung and fibrosis. Although the etiology of IPF is unknown, it is likely to involve an interaction between environmental and multiple genetic components. Animal models of pulmonary fibrosis have shown that proinflammatory mediators are critical at both the inflammatory and fibrotic stages of the disease. Genetic variants exist in genes encoding proinflammatory mediators, as well as in genes encoding their receptors, which makes these genes candidates for the pathogenesis of IPF. In the present study, we examined 12 biallelic polymorphisms in the genes for tumor necrosis factor (TNF)-alpha (+488[G/A], -238[G/A], -308[G/A]), lymphotoxin (LT)-alpha (+720[C/A], +365[C/G], and +249[A/G], determining haplotypes LT-alpha1 to LT-alpha4), tumor necrosis factor-receptor 2 (TNF-RII) (gb:M32315: 676[T/G], 1663[A/G], 1668[T/G], 1690[C/T]), and interleukin- (IL)-6 (promoter -174[G/C], intron 4[A/G]). We also examined the haplotypes determined by the three biallelic polymorphisms in each of the TNF-alpha and LT-alpha genes. As compared with a normal control population, the IPF group showed no significant deviations in genotype, allele, or haplotype frequencies. Surprisingly, in the IPF population, but not in the control population, an increased frequency of cocarriage of the IL-6 intron 4G and the TNF-RII 1690C alleles was observed, despite the location of the two genes on different chromosomes. Moreover, using impairment of carbon monoxide transfer (DL(CO)) adjusted for duration of dyspnea as a marker of rapidity of disease progression, we found that the IL-6 intron 4GG genotype was the only genotype independently associated with lower DL(CO) levels. These findings, if independently confirmed, will be the first to suggest that disease progression in IPF may be linked to a particular genetic marker or to functional polymorphisms in other genes near that marker.

Up-regulation of IL-8 secretion by alveolar macrophages from patients with fibrosing alveolitis: a subpopulation analysis

Neutrophil accumulation in the lower respiratory tract of patients with fibrosing alveolitis is thought to be facilitated by IL-8, a neutrophil chemoattractant primarily secreted by mononuclear phagocytes. The aims of this study were: (i) to explore IL-8 secretion by lung and blood mononuclear phagocytes in subjects with cryptogenic fibrosing alveolitis, systemic sclerosis with and without fibrosing alveolitis, sarcoidosis and normal individuals; (ii) to examine IL-8 secretory heterogeneity in alveolar macrophages and peripheral blood monocytes; and (iii) to correlate alveolar macrophage phenotypic profile to IL-8 secretion. We observed that more monocytes secreted IL-8 than autologous macrophages and that there was heterogeneity in the in vitro IL-8 secretion by alveolar macrophages and peripheral blood monocytes. IL-8 secretion by alveolar macrophages was significantly higher in subjects with fibrosing alveolitis compared with subjects without fibrosing alveolitis, due to a higher percentage of IL-8-secreting alveolar macrophages in the fibrotic group both in the absence (P < 0.002) and presence of lipopolysaccharide (LPS) (P < 0.04) and correlated with bronchoalveolar lavage neutrophil percentage. Using the MoAbs RFD1, RFD7 and RFD9, that distinguish subsets of alveolar macrophages, we have been able to identify associations between secretion of IL-8 and smaller cells and the cells identified by the MoAb RFD7. In situ hybridization of the bronchoalveolar lavage cell population revealed that alveolar macrophages are the predominant source of IL-8 in the lung. We conclude that there is an increased number of IL-8-secreting alveolar macrophages in the lungs of patients with fibrosing alveolitis, and IL-8 secretion by these cells is associated with specific phenotypic profile expression.

Primary epithelioid angiosarcoma of the lung presenting as pulmonary hemorrhage

Pulmonary angiosarcomas are usually secondary tumors, and only a few primary cases have been described. We report a unique case of epithelioid angiosarcoma arising in the lungs as a bilateral multinodular infiltrate and presenting as pulmonary hemorrhage. Because of its epithelioid histology, this tumor may resemble a carcinoma, also staining positively for keratin markers. Therefore, unless the diagnosis of epithelioid angiosarcoma is considered and endothelial markers used, the diagnosis of epithelioid angiosarcoma may be overlooked at this site.

The intrapulmonary half-life and safety of aerosolized alpha1-protease inhibitor in normal volunteers

Aerosol delivery of alpha1-protease-inhibitor (alpha1-PI) has the potential for reducing the amount of alpha1-PI needed to treat persons who are severely alpha1-PI-deficient, thereby decreasing the high cost of treatment and making alpha1-PI available to treat many alpha1-PI-deficient persons who do not now have access to that product. Aerosolized alpha1-PI may also be useful in cystic fibrosis. The goal of our study was to evaluate the duration of action of aerosolized alpha1-PI and possible side effects in normal volunteers. Twenty-nine volunteers underwent bronchoalveolar lavage (BAL) and 3 to 7 d later inhaled 200 mg of alpha1-PI. Subjects were subsequently assigned to one of five groups; a second BAL was performed 0.5, 6, 12, 24, or 36 h after the aerosol, respectively. The BAL fluid samples were analyzed for alpha1-PI concentrations, anti-neutrophil elastase (NE) activity, cell count and differential, alpha1-PI-NE complex level, and uptake of alpha1-PI by alveolar macrophages. Overall we observed no substantial side effects. The one-time alpha1-PI aerosol induced a significant increase of alpha1-PI concentrations as well as anti-NE activity. Even in the BAL fluid samples obtained 36 h after aerosol administration alpha1-PI concentrations and anti-NE activity were about double baseline values. The half-time in the lungs for alpha1-PI concentrations and anti-NE activity were about double baseline values. The half-time in the lungs for alpha1-PI was 69.2 h and for anti-NE activity was 53.2 h, respectively. We conclude from our data in normal volunteers that inhalation of aerosolized alpha1-PI may be a safe, effective, and conveniently administered therapy for persons with severe alpha1-PI deficiency; this mode of administration warrants further study.

Fibrosing alveolitis in systemic sclerosis. Bronchoalveolar lavage findings in relation to computed tomographic appearance

Fibrosing alveolitis in systemic sclerosis is histologically identical to lone cryptogenic fibrosing alveolitis (CFA) (idiopathic pulmonary fibrosis). The inflammatory cell content of bronchoalveolar lavage (BAL) samples has been used as a guide to prognosis and treatment in CFA. In this study, the relationship was explored between BAL findings and the extent and pattern of disease within the lavaged lobe, as judged by thin-section computed tomography (CT), in systemic sclerosis. Thirty-eight nonsmoking patients were studied; none had been treated with corticosteroids or immunosuppressive agents, and 11 had no evidence of fibrosing alveolitis on CT. BAL neutrophils were markedly increased in association with extensive disease on CT compared with less extensive disease (p < 0.001) and normal appearances (p < 0.001); the extent of a reticular pattern on CT (denoting fibrosis) correlated with the neutrophil percentage count (p < 0.005) and total neutrophil count/ml (p < 0.01). BAL eosinophils were increased in less extensive as well as in extensive disease when compared with lobes with a normal CT appearance (p < 0.01); eosinophil percentage counts but not total eosinophil counts/ml correlated with the extent of a ground-glass pattern on CT (through to denote inflammation) (p < 0.05). These findings indicate that in systemic sclerosis a BAL neutrophilia is generally associated with extensive fibrotic disease, whereas a BAL eosinophilia is often seen in less advanced disease, particularly when CT appearances suggest lung inflammation.

Fibrosing alveolitis associated with systemic sclerosis has a better prognosis than lone cryptogenic fibrosing alveolitis

Fibrosing alveolitis associated with systemic sclerosis (FASSc) is considered to be histologically and radiologically indistinguishable from lone cryptogenic fibrosing alveolitis (CFA). To date, the natural history of the two diseases has not been compared directly in large groups of patients followed at a single institution. We evaluated the survival of 205 patients with CFA and 68 patients with FASSc. Deaths during the follow-up period were reported in 142 patients with CFA (70%) and in 11 patients with FASSc (16%). Unadjusted survival from the onset of dyspnea was less in CFA than in FASSc (odds ratio, 3.3; p < 0.001); this difference persisted after adjustment for age of onset of dyspnea and smoking history. Survival from presentation was less in CFA (odds ratio approximately 3.3) after adjustment for age of presentation, smoking history, and initial pulmonary function indices. These differences persisted when analysis was confined to patients with histologic confirmation of fibrosing alveolitis and after adjustment for treatment. In patients undergoing computed tomography (CT) of the lungs, survival was less in CFA after adjustment for extent of abnormal lung on CT and CT pattern of disease (odds ratio, 3.9; p < 0.001). These findings indicate that despite their histologic and radiologic similarities, lone CFA and FASSc have different courses.

T-lymphocytes that accumulate in the lung in sarcoidosis have evidence of recent stimulation of the T-cell antigen receptor

Sarcoidosis, a granulomatous disease of unknown etiology, is characterized at sites of disease such as the lung by the accumulation of large numbers of T-lymphocytes. To differentiate whether the T-cells accumulate in organs nonspecifically (e.g., through chemotaxis or tumorlike proliferation) or more specifically through an antigen-driven ordered immune response, the present study capitalized on the knowledge that specific antigen stimulation of T-cells requires antigen interactions with the T-cell antigen receptor (TCR), resulting in a decrease in the number of surface TCR and a concomitant increase in TCR mRNA levels, i.e., if lung T-cell accumulation in pulmonary sarcoid results from an ordered immune response, lung, but not blood, T-cells should demonstrate evidence of recent triggering of the alpha beta receptor, the most abundant type of TCR. The surface density of T-cell surface alpha beta TCR expression was evaluated by flow cytometry with an anti-alpha beta antibody and TCR beta-chain mRNA transcript number quantified by in situ hybridization with 35S-labeled antisense and sense cRNA probes. Control studies utilizing normal blood T-lymphocytes stimulated with the anti-CD3 monoclonal antibody, OKT3, in the presence of autologous monocytes, demonstrated the expected down-regulation of surface alpha beta TCR expression and increased beta-chain mRNA transcript number. When lung and blood T-cells of patients with pulmonary sarcoidosis were compared immediately upon recovery (i.e., without in vitro stimulation), the lung T-cells of 10 of 10 subjects demonstrated a decreased surface density of alpha beta TCR compared with their autologous blood T-cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural features of interstitial lung disease in systemic sclerosis

Most studies of lung histology in systemic sclerosis have been based on autopsy specimens and consequently emphasize end-stage fibrotic disease. Although occasional pathologic descriptions of open-lung biopsies have recognized the presence of inflammatory cells, suggesting a similarity to "lone" cryptogenic fibrosing alveolitis, the two conditions have never been formally compared. In this study we describe the morphologic features of 49 open-lung biopsies from 34 systemic sclerosis patients with interstitial lung disease, many of whom had their lung disease diagnosed at an early stage. None had pulmonary hypertension. Examination of lung tissue by light microscopy showed the earliest changes to include patchy lymphocyte and plasma cell infiltration of the alveolar walls, interstitial fibrosis, and increased macrophages but only occasional polymorphonuclear cells and lymphocytes in the alveolar spaces. Alveolitis was not observed without fibrosis. Comparison of 22 biopsies with a similar number from patients with lone cryptogenic fibrosing alveolitis, matched for age and sex, revealed no qualitative or quantitative differences, other than a higher prevalence of focal lymphoid hyperplasia (follicular bronchiolitis) in the systemic sclerosis patients than in the lone cryptogenic fibrosing alveolitis controls (23 and 5%, respectively). There was an inverse correlation between the extent of interstitial inflammation and patients' age (p less than 0.05), disease duration (p less than 0.05), and age at onset of systemic sclerosis (p less than 0.01). There was also an inverse correlation between DLCO and interstitial fibrosis (p less than 0.01) and loss of lung architecture (p less than 0.05). Ultrastructural studies of eight systemic sclerosis biopsies showed evidence of endothelial and epithelial injury together with interstitial edema and excess collagen deposition. Occasional mast cells were observed, often in close contact with interstitial fibroblasts, but there were no tubuloreticular structures or evidence of immune complexes.(ABSTRACT TRUNCATED AT 250 WORDS)

Pneumonitis in bone marrow transplant recipients results from a local immune response

Eighteen recipients of allogeneic T cell-depleted bone marrow who developed 22 episodes of interstitial pneumonitis were investigated by bronchoalveolar lavage for the cause of pneumonitis. The cells obtained were examined using a panel of monoclonal antibodies with immunocytochemical techniques to identify lymphocyte subsets and the presence of surface molecules indicative of lymphocyte activation. The majority of patients had an excess of lymphocytes in lavage and most of these cells were positively stained with the McAb recognizing the CD8 antigen (suppressor/cytotoxic type T cells). Although the proportions of CD4+ (helper type) T cells were below normal, the absolute numbers were within normal limits, thus the CD4:CD8 ratio was consistently 1:1 or less. A large proportion of the CD8+ cells displayed HLA-DR molecules (RFDR1+), interleukin-2 (IL-2) receptors (CD25+) and high concentration of CD7 antigen (RFT2+). Further analysis revealed that most CD8+ cells were CD5+ (RFT1+) yet a large proportion (20-40%) were CD5-. A majority of CD8+ cells was also CD38+ (RFT10+) and Leu7+. No clear correlation between the emergence of a raised proportion of activated CD8+ cells and diagnosed cytomegalovirus infection was found. These results demonstrate, however, that cells with the phenotype of the resident T cells of the bronchial epithelium (CD8+CD5-) emerge to the air spaces and express activation markers. This raises the intriguing paradox of an aggressive local immune response occurring in an otherwise immunosuppressed group of patients.

The distribution of phenotypically distinct macrophage subsets in the lungs of patients with cryptogenic fibrosing alveolitis

Monoclonal antibodies that identify phenotypically distinct macrophage subsets were used to analyse the macrophages in lung biopsy specimens and bronchoalveolar lavage fluid from patients with cryptogenic fibrosing alveolitis. Among the antibodies were RFD1, an interdigitating cell marker, RFD7, a marker for mature tissue macrophages, and RFD9, which identifies epithelioid cells as well as germinal centre macrophages. The lavage fluid was found to contain abnormally high numbers of cells staining with each of the antibodies, a finding that could be explained, at least in part, by an increased frequency of cells expressing more than one marker. In lung tissue macrophage phenotypes within the interstitium were found to differ significantly from those in the alveolar space. Most strikingly, cells bearing the antigen recognized by RFD9 were entirely absent from the interstitial macrophage population, whereas the vast majority in the alveolar lumen were RFD9-positive. The discrete compartmentalization of phenotypically different macrophages within the lung suggests that macrophages may contribute differently to lung pathology in each microenvironment. The functional capacity of the unusual RFD9-positive alveolar macrophages remains to be determined, but their close association with the process of alveolar occlusion indicates a role in the fibrotic process.

Suppression associated lymphocyte markers in lesions of sarcoidosis

The presence within the epithelioid granulomas of sarcoidosis of lymphocytes of the "helper" (T4 positive) phenotype suggests that, as in granulomatous diseases of known aetiology, active cell mediated immunity plays a part in the disease. It has, however, been noted that T8 positive lymphocytes are also found on occasion in the granulomas. The presence of cells bearing markers associated with suppressor activity in various lesions of sarcoidosis has been investigated with a range of monoclonal antibodies. T4 positive cells were present in all granulomas; T8 positive lymphocytes were present within the epithelioid cell areas in proportions that varied from 5 to 55/100 of T4 cells. Other lymphocyte markers associated with suppression (Leu8 and SN130) were very rare on lymphocytes within granulomas but common on both T4 positive and T8 positive lymphocytes in the perigranulomatous mantle, which suggests that expression of these markers was down regulated in the granuloma or that cells bearing them are unable to migrate into the granuloma. Nevertheless, suppressor cell mechanisms could mediate the spontaneous resolution of most cases of sarcoidosis, and the presence or absence of cells bearing suppression associated phenotypes in the granuloma or its mantle may have prognostic importance.

Dendritic cells in cutaneous, lymph node and pulmonary lesions of sarcoidosis

To determine whether dendritic cells (DC) are a consistent feature of lesions of sarcoidosis, we have used monoclonal antibodies to identify the HLA-DR-expressing populations of cells in cryostat sections of 15 lymph node, pulmonary and cutaneous lesions. The commonest HLA-DR positive cells in granulomas were epithelioid and giant cells, although lymphocytes within granulomas and tissue macrophages around them were also positive. Dendritic cells with Langerhans cells (NA1/34+ = OKT6+) and interdigitating cell (RFD1+) phenotype were consistently associated with granulomas only in skin lesions. In lymph nodes, interdigitating cells (NA1/34-/RFD1+/HLA-DR++) were confined to paracortical zones as in normal nodes, although a small area of NA1/34+/RFD1+ cells was found in one of three nodes. In lung lesions NA1/34+/RFD1+ dendritic cells were uncommon or absent, except in one chronic case. We conclude that while sometimes present in extracutaneous sites, DC are not an essential feature of sarcoid lesions, and that cells of the classical macrophage group are the most significant HLA-DR-expressing population. We suggest that the presence of DC in lesions of sarcoidosis may indicate an immunological response distinct from that causing granulomas to form. The variability of their involvement may have immunoregulatory significance.

Phenotypic analysis of alveolar macrophages in normal subjects and in patients with interstitial lung disease

Cytospin preparations of mononuclear inflammatory cells were made from bronchoalveolar lavage fluid obtained from 15 patients with interstitial lung disease (nine patients with sarcoidosis and six patients with cryptogenic fibrosing alveolitis) and six control subjects. These preparations were examined with a panel of monoclonal antibodies that have been shown to distinguish subpopulations of macrophage like cells in normal tissues. The lysosomal acid phosphatase activity of the cells was also assessed. Phenotypically distinct subpopulations of alveolar macrophages were identified in all samples studied. The results showed that all cell populations identified in bronchoalveolar lavage fluid from the groups with interstitial lung disease could be identified in the lavage fluid from normal volunteers. Some quantitative differences in the proportions of cells identified with particular reagents emerged. In each of the groups with interstitial lung disease increased proportions of cells were identified with RFD1 (interdigitating cell marker; p less than 0.01) and in the cryptogenic fibrosing alveolitis group an increased proportion of alveolar macrophages was identified with RFD7 (tissue macrophage marker; p less than 0.05). The possibility that quantitative changes in alveolar macrophage subsets observed in the interstitial lung disease groups are relevant to the pathogenesis of these conditions is discussed.

Alveolar proteinosis: diagnosis and treatment over a 10-year period

Ten years' experience of using bronchoalveolar lavage in the treatment of 10 patients with alveolar proteinosis is reported. The diagnosis was often missed. The interval between onset of symptoms and diagnosis varied from six weeks to six years (median 2 years), so that the start of treatment was often delayed. Some patients experienced severe progressive disability before they had treatment. Whole-lung lavage proved to be a safe, repeatable procedure which provided symptomatic, physiological, and radiological improvement and allowed all 10 patients treated to return to full-time employment.

Asthma, aspergilloma and anergy in a patient being treated for pulmonary tuberculosis

A twenty-one-year old white girl developed cavitating pulmonary tuberculosis which was complicated by nocturnal asthma, aspergilloma and anergy. In addition she developed systemic symptoms suggestive of a hypersensitivity reaction to the aspergilloma.