Bone density is normal and does not change over 2 years in sarcoidosis.

SUMMARY: Small studies have previously suggested that sarcoidosis may be associated with low bone mineral density. In this observational study of 64 patients with sarcoidosis, bone mineral density was within the normal range at baseline, and there was no evidence of accelerated bone loss over 1-2 years. INTRODUCTION: Several small studies have suggested that sarcoidosis may be associated with low bone mineral density (BMD). METHODS: We undertook a cross-sectional study of BMD in 64 patients with sarcoidosis. Of these, 27 with 25-hydroxyvitamin D<50 nmol/L entered a 1-year intervention study of vitamin D supplements, and 37 entered a 2-year longitudinal study of BMD, with the primary endpoint of the change in lumbar spine BMD. RESULTS: The mean age of participants was 58 years, 68% were female, and 8% were currently using oral glucocorticoids. At baseline, BMD for the entire cohort was greater than the expected values for the population at the lumbar spine (mean Z-score 0.7, P<0.001) and total body (0.5, P<0.001) and similar to expected values at the femoral neck (0.2, P=0.14) and total hip (0.2, P=0.14). BMD did not change at any of these four sites (P>0.19) over 2 years in the longitudinal study. In the intervention study, vitamin D supplements had no effect on BMD, and therefore we pooled the data from all participants. BMD did not change over 1 year at the spine, total hip, or femoral neck (P>0.3), but decreased by 0.7% (95% confidence interval 0.3-1.1) at the total body (P=0.019). CONCLUSIONS: BMD was normal at baseline, and there was no consistent evidence of accelerated bone loss over 1-2 years, regardless of baseline vitamin D status. Patients with sarcoidosis not using oral glucocorticoids do not need routine monitoring of BMD.

Does CT scanning predict the likelihood of a positive transbronchial biopsy in sarcoidosis?

BACKGROUND: Transbronchial lung biopsy (TBB) has a variable diagnostic yield in sarcoidosis. It was hypothesised that the extent and pattern of parenchymal disease on CT scanning would predict the likelihood of a positive TBB result. METHODS: Patients with sarcoidosis (n = 77) were included if they had undergone a CT scan within 6 weeks of TBB. Ethnicity, symptoms, pulmonary function and site and results of TBB and bronchoalveolar lavage (BAL) were recorded. CT scans were scored quantitatively for patterns of parenchymal disease (nodular, reticular, consolidation and ground glass) on a lobar basis. RESULTS: 39 patients (50.6%) had a positive TBB. Symptoms, ethnicity, treatment, lung volumes and chest radiographic stage were not predictors of a positive biopsy. Female gender, reduced percentage predicted carbon monoxide transfer factor and a higher percentage of lymphocytes in the BAL fluid were associated with a positive biopsy, as were higher total lung score, reticular pattern and ground-glass opacity. The associations were more significant for the total lobar score and the lobar ground-glass score of the lobe biopsied. On multivariate analysis gender, percentage of lymphocytes in the BAL fluid and total lung score were independent predictors of a positive TBB. CONCLUSION: The total extent of parenchymal disease on the CT scan in addition to the pattern and lobar distribution predicts the likelihood of a positive TBB at bronchoscopy.

Transtracheal needle aspiration.

A series of 27 transtracheal needle aspiration biopsies performed on 25 patients were reviewed. A rigid bronchoscope and rigid needle were used. The biopsies were performed as staging procedures in patients with bronchogenic carcinoma, or to obtain diagnoses in patients with mediastinal adenopathy. A cytopathologist attended 11 biopsies and microscopically examined a direct smear to determine adequacy. Repeat biopsies were taken at the time if necessary. A diagnosis was obtained in 9/11 (81%) of these cases. Only 3/16 biopsies (18.8%) performed in the absence of a pathologist were diagnostic. All negative cases were subsequently found to have disease (2 sarcoidosis, 13 cancer) by other methods including mediastinoscopy in 5 cases. In the patient group sampled, the technique of rigid needle and rigid bronchoscope with a cytopathologist in attendance resulted in a much higher sensitivity for the test than has been previously reported.

Cystic fibrosis diagnosed in adult patients.

AIM: To review the presentation, diagnosis and long-term, clinical follow-up of cystic fibrosis in adult patients diagnosed in adulthood at Green Lane Hospital. METHODS: A retrospective review of the case notes of patients with cystic fibrosis diagnosed in adulthood at Green Lane Hospital or referred there for management. Information was collected on diagnostic tests, including sweat tests and genotyping. Relevant family history was documented as were spirometry results and microbial colonisation. RESULTS: Six patients conclusively fulfilled the diagnostic criteria for cystic fibrosis. There was a wide range of ages at diagnosis (18-68) and half of the patients had a positive family history. A single mutation was identified in all, but in only one of the cases was the second mutation identified. All patients had evidence of bronchopulmonary suppuration and all had retained pancreatic function. Colonisation with P aeruginosa was associated with marked impairment in lung function. CONCLUSION: The patients at Green Lane Hospital represent part of the broad-spectrum disease in adult patients diagnosed with cystic fibrosis and highlight the differences between this group and those patients diagnosed in childhood with the more classical phenotype. Patients generally have less severe lung disease and retain pancreatic function. Sweat testing is useful diagnostically but gene testing is of limited value in making the diagnosis.

Hypoxic pulmonary vasoconstriction as a contributor to response in acute pulmonary embolism.

Hypoxic pulmonary vasoconstriction (HPV) is an adaptive response unique to the lung whereby blood flow is diverted away from areas of low alveolar oxygen to improve ventilation-perfusion matching and resultant gas exchange. Some previous experimental studies have suggested that the HPV response to hypoxia is blunted in acute pulmonary embolism (APE), while others have concluded that HPV contributes to elevated pulmonary blood pressures in APE. To understand these contradictory observations, we have used a structure-based computational model of integrated lung function in 10 subjects to study the impact of HPV on pulmonary hemodynamics and gas exchange in the presence of regional arterial occlusion. The integrated model includes an experimentally-derived model for HPV. Its function is validated against measurements of pulmonary vascular resistance in normal subjects at four levels of inspired oxygen. Our results show that the apparently disparate observations of previous studies can be explained within a single model: the model predicts that HPV increases mean pulmonary artery pressure in APE (by 8.2 ± 7.0% in these subjects), and concurrently shows a reduction in response to hypoxia in the subjects who have high levels of occlusion and therefore maximal HPV in normoxia.

Pulmonary embolism: predicting disease severity.

Pulmonary embolism (PE) is the most common cause of acute pulmonary hypertension, yet it is commonly undiagnosed, with risk of death if not recognized promptly and managed accordingly. Patients typically present with hypoxemia and hypomania, although the presentation varies greatly, being confounded by co-morbidities such as pre-existing cardio-respiratory disease. Previous studies have demonstrated variable patient outcomes in spite of similar extent and distribution of pulmonary vascular occlusion, but the path physiological determinants of outcome remain unclear. Computational models enable exact control over many of the compounding factors leading to functional outcomes and therefore provide a useful tool to understand and assess these mechanisms. We review the current state of pulmonary blood flow models. We present a pilot study within 10 patients presenting with acute PE, where patient-derived vascular occlusions are imposed onto an existing model of the pulmonary circulation enabling predictions of resultant haemodynamic after embolus occlusion. Results show that mechanical obstruction alone is not sufficient to cause pulmonary arterial hypertension, even when up to 65 per cent of lung tissue is occluded. Blood flow is found to preferentially redistribute to the gravitationally non-dependent regions. The presence of an additional downstream occlusion is found to significantly increase pressures.

Exhaled nitric oxide in sarcoidosis.

BACKGROUND: Increased production of nitric oxide (NO) by the lower respiratory tract is viewed as a marker of airway inflammation in asthma and bronchiectasis. NO is a potentially important immune modulator, inhibiting the release of several key pro-inflammatory cytokines. As sarcoidosis is characterised by granulomatous airway inflammation, we hypothesised that exhaled NO levels might be raised in sarcoidosis and correlate with the morphological extent and functional severity of disease. METHODS: Fifty two patients with sarcoidosis (29 men) of mean age 42 years underwent thin section computed tomography (CT), pulmonary function tests, and measurement of exhaled NO. RESULTS: Exhaled NO levels (median 6.8 ppb, range 2.4-21.8) did not differ significantly from values in 44 control subjects, and were not related to the extent of individual CT abnormalities or the level of pulmonary function impairment. CONCLUSION: Exhaled NO levels are not increased in pulmonary sarcoidosis.

Seasonal clustering of sarcoidosis presenting with erythema nodosum.

Seasonal clustering of sarcoidosis presenting with erythema nodosum (EN) has previously been reported only in the northern hemisphere. Of 59 patients presenting to a single centre in New Zealand with a new diagnosis of sarcoidosis, 21 had EN and three more had acute arthralgia without EN. These patients were compared with the rest of the cohort. The patients with EN or arthralgia alone presented exclusively between April and December, with peak clustering in the spring months of August, September and October (p<0.001, Fisher's exact test). This cohort was more likely to have a stage I chest radiograph and to be female (p<0.05), but there were no other differences between the groups. This is the first report of seasonal clustering in the southern hemisphere suggesting a common environmental trigger in the aetiology of sarcoidosis.

Transtracheal aspiration using rigid bronchoscopy and a rigid needle for investigating mediastinal masses.

BACKGROUND: Use of the flexible needle via the fibreoptic bronchoscope to aspirate mediastinal nodes or masses has largely superseded the use of the rigid needle via the rigid bronchoscope. However, the yield at fibreoptic bronchoscopy is relatively low, although this improves with the use of a wider gauge needle. In this study the sensitivity and the safety of rigid needle sampling of the mediastinum in the diagnosis of lung cancer is evaluated. METHODS: Transtracheal needle aspiration (TTNA) was performed with the rigid bronchoscope and a rigid aspiration needle under general anaesthesia using a previous computed tomographic (CT) scan as a guide to the sample site. A cytopathologist immediately examined the specimens for adequacy and preliminary diagnosis, thus determining the number of aspirations. RESULTS: Twenty four patients were evaluated. The diagnostic sensitivity of TTNA was 88%. This led to a management decision in 21 patients. There were no false positives and no complications. CONCLUSIONS: TTNA using the rigid bronchoscope with CT scanning and a cytopathologist present is a sensitive and safe way of diagnosing lung cancer in patients with a mediastinal mass or enlarged mediastinal nodes.

Medical thoracoscopy in the diagnosis of unexplained pleural effusion.

Approximately 20% of pleural effusions remain without an established aetiology after evaluation. Thoracoscopy has a very high sensitivity for the diagnosis of both benign and malignant diseases and greatly increases the diagnostic yield for pleural effusion. We sought to evaluate the diagnostic yield and safety of medical thoracoscopy at this institution. The records of all patients undergoing medical thoracoscopy for the evaluation of undiagnosed pleural effusion between 1990 and 1996 were reviewed. The procedure was performed under local anaesthesia with sedation using a Stortz rigid thoracoscope. Fifty-eight patients had thoracoscopy, most having had two (range: 1-6) non-diagnostic pleural aspirations and biopsies of the pleura. Nineteen patients were found to have mesothelioma and nine metastatic malignancy. Three patients were considered likely to have tuberculous pleural disease, six had asbestos related benign pleural fibrosis and three post-cardiotomy syndrome. There was one chylous effusion of uncertain aetiology, one posttraumatic and two other benign effusions, both of which resolved without clear aetiology. On seven occasions the pleural space could not be adequately accessed, but none of these patients had prior computerized tomography (CT) or ultrasound of the pleural space. There were five false negative diagnoses of malignancy, but no false positives. The diagnostic sensitivity for pleural malignancy was 85% and specificity 100%. There were no major complications, but four patients had late tumour seeding at the thoracoscopy site. Medical thoracoscopy is a safe procedure with a high diagnostic yield. Pre-operative evaluation of the pleural collection using ultrasound or CT increases the likelihood of successful access to the pleural space and may increase diagnostic yield.

Immunoregulatory properties of pulmonary surfactant: effect of lung lining fluid on proliferation of human blood lymphocytes.

Human pulmonary surfactant has not been shown to have immunoregulatory properties. A study was designed to examine the effect of whole surfactant (lyophilised bronchoalveolar lavage fluid) and purified surfactant lipids obtained from normal lungs of three species (man, pig, rabbit) on the lymphoproliferative responses of human peripheral blood lymphocytes to mitogens and alloantigens. Whole surfactant and purified surfactant lipids suppressed the proliferative response to phytohaemagglutinin in a dose dependent manner. The purified lipid fraction appeared to cause more suppression than whole surfactant in all the species. There was significant suppression of the proliferative response to B cell mitogens, T cell mitogens (pokeweed mitogen and phytohaemagglutinin), and alloantigens as tested by allogeneic mixed lymphocyte cultures. These results suggest an immunoregulatory role for pulmonary surfactant, most likely due to the lipid fraction.

Immunoregulatory properties of pulmonary surfactant: influence of variations in the phospholipid profile.

The aim of this study was to seek in vitro evidence to support our hypothesis that the immunosuppressive properties of pulmonary surfactant might be influenced by variations in phospholipid composition. Dose response studies conducted in serum-free medium, have demonstrated that pure phospholipids of the major types found in pulmonary surfactant, namely phosphatidylcholine (PC), phosphatidylglycerol (PG) and phosphatidylinositol (PI) exhibit significant dose dependent suppression of lymphocyte response to phytohaemagglutinin (PHA) (PC greater than PG greater than PI). By contrast, phosphatidylethanolamine (PE), sphingomyelin (SM), and the neutral lipid cholesterol (CH) augment the lymphoproliferative response in serum-free medium. The degree of suppression obtained using mixtures of various ratios of PC, PG and PI depended on the proportion of the most suppressive phospholipids (PC and PG). Similarly, increasing the proportion of PC in mixtures containing variable proportions of PE or CH resulted in increasing suppression of lymphoproliferation. Comparisons of the lipid fractions purified from pulmonary surfactant of three species (human, pig and rabbit) showed that the levels of suppression they induced reflected their relative content of phospholipids with the greatest immunosuppressive properties. We conclude that variations in phospholipid composition may affect the immunoregulatory properties of pulmonary surfactant.

Immunomodulatory effects of pulmonary surfactant on natural killer cell and antibody-dependent cytotoxicity.

Alveolar natural killer (NK) cells are functionally weak compared to their blood and interstitial counterparts. Having previously demonstrated that pulmonary surfactant suppresses lymphocyte responses to a variety of stimuli we sought in this study to determine if surfactant exerts a similar suppressive effect on cytotoxic function. Lipids were purified from the bronchoalveolar lavage (BAL) fluid from normal human volunteers. Human peripheral blood lymphocytes (n = 10 subjects) were cultured overnight in the presence or absence of purified BAL lipids (0.2 mg/ml), or pure preparations of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylglycerol (PG) (0.4 mg/ml). Standard NK and antibody-dependent cytotoxicity (ADCC) assays were performed using K562 and Chang target cells. The pooled BAL lipids significantly suppressed both NK (P less than 0.01) and ADCC (P = 0.01) activity in a dose-dependent manner. Whereas pure PC did not exert a significant effect, PG significantly suppressed (P less than 0.01) and PE significantly enhanced (P less than 0.01) both cytotoxic functions. There was no change in the expression of leu 7 or 11b antigens by lymphocytes after culture in BAL lipids. These results suggest that under normal circumstances pulmonary surfactant may suppress alveolar cytotoxic responses but that imbalances in the phospholipid profile might affect this immunoregulatory property.

Gamma/delta T lymphocytes in the blood of patients with sarcoidosis.

BACKGROUND: Gamma/delta T lymphocytes are thought to have a role in granulomatous immune responses at peripheral sites of antigen contact such as the gut, skin and lung. The aim of this study was to determine if gamma/delta T lymphocytes are increased in the peripheral blood of patients with active sarcoidosis. METHODS: Peripheral blood from 21 untreated patients with a new presentation of sarcoidosis (12M, 9F), 20 normal volunteers (12M, 8F), and 12 patients with cavitary pulmonary tuberculosis were subjected to Ficoll Hypaque separation and flow cytometry analysis using monoclonal antibodies to CD3, 4, 8, 25, HLA-DR and gamma/delta T cell receptor. RESULTS: All patients with sarcoidosis had compatible chest radiographs and all were Mantoux negative in spite of previous BCG vaccination. In all but one patient histological examination showed non-caseating granuloma. There was no difference in the mean percentage or absolute numbers of gamma/delta positive peripheral blood lymphocytes between the three populations. Thirteen patients with sarcoidosis had an absolute lymphopenia and the mean percentage of CD3 positive peripheral blood lymphocytes in the group with sarcoidosis was lower than the other two groups. The percentage of CD25 and HLA-DR positive cells was higher in the group with sarcoidosis, supporting the fact that these patients had active disease. CONCLUSION: Gamma/delta T lymphocytes are not increased in the peripheral blood of patients with sarcoidosis and are unlikely to have a role in the pathogenesis of this disease.

Gamma/delta cells in tissue from patients with sarcoidosis.

BACKGROUND: Because gamma/delta T lymphocytes (gamma delta cells) respond to myco-bacterial antigens in vitro and accumulate in the skin lesions of patients with certain granulomatous infections (leprosy, leishmaniasis), it was hypothesised that these cells might have a role in the pathogenesis of sarcoidosis, a disease also characterised by granuloma formation. Having failed to demonstrate an increase in gamma delta cells in the blood of patients with sarcoidosis, the aim of this study was to examine samples of bronchoalveolar lavage (BAL) fluid and biopsy tissue. METHODS: Samples from 23 patients (13 women) with newly diagnosed sarcoidosis, of mean age 31 years and median percentage of lymphocytes in the BAL fluid of 31%, were studied. Controls included normal subjects and patients with other interstitial lung diseases (ILD). Cytopreparations of BAL fluid (n = 13) and cryostat sections (five mediastinal nodes, 14 transbronchial biopsies) were stained with alkaline phosphatase-antialkaline phosphatase and monoclonal antibodies to CD3, CD4, CD8, CD25, and gamma delta T cell receptor (TCR). RESULTS: All patients had typical chest radiographs (16 stage I, four stage II, three stage III). All were Mantoux negative with negative tuberculosis cultures. Compared with normal controls and patients with other interstitial lung diseases there was no increase in gamma delta cells in the BAL fluid (sarcoidosis, 1% (range 0-4%) total cells; ILD, 1% (0-2%); controls, 0.5% (0-2%); p > 0.05, Kruskal-Wallis). Likewise, there was no increase in gamma delta cells in the transbronchial biopsy specimens (sarcoidosis, 1/high power field (hpf) (range 0-2); ILD, < 1/hpf (0-4); controls < 1/hpf (0-2); p > 0.05). gamma delta cells were rarely seen in the lymph nodes in spite of the presence of numerous granulomas. CONCLUSION: These results provide further evidence that gamma delta cells are not increased in most patients with sarcoidosis.

Immunosuppression by pulmonary surfactant: mechanisms of action.

Pulmonary surfactant has been shown by this group to suppress peripheral blood lymphocyte responses to mitogens and alloantigens in a dose dependent manner, though the mechanism of action of the suppressive effect is not clearly understood. To try to clarify this, attempts were made to reverse the effects of preincubation with surfactant, obtained by bronchoalveolar lavage from pigs, on lymphocytes and accessory monocytes obtained from the blood of normal volunteers, by washing and incubating the cells in medium alone for various periods up to 24 hours. Immunosuppression, measured as the reduction in thymidine incorporation in response to the mitogen phytohaemagglutinin, could not be reversed by these methods. The addition of indomethacin (up to 100 micrograms/ml for 72 hours) also had no effect, indicating that the immunosuppression was not related to synthesis of prostaglandins. Incubation with surfactant for as little as two hours before addition of mitogen suppressed in vitro lymphoproliferative responses by half, but surfactant added two hours after mitogen had no observed effect. Preincubation of purified lymphocytes in surfactant, before they were cultured with accessory monocytes and mitogen, caused significant suppression of response, but preincubation of purified monocytes had no suppressive effect. There was no change in the intensity of HLA-DR expression on monocytes. These results support the hypothesis that surfactant exerts its effects on the resting uncommitted lymphocyte rather than on antigen presenting monocytes.

Mycobacterium tuberculosis DNA in tissues affected by sarcoidosis.

BACKGROUND: Although some studies have reported the presence of Mycobacterium tuberculosis (MTb) DNA in tissues affected by sarcoidosis, the data are conflicting. The aim of this study was to collect prospectively tissue from patients with sarcoidosis in whom tuberculosis had been excluded, and to use polymerase chain reaction (PCR) to search for DNA sequences specific for MTb. METHODS: Fresh tissue samples (node or lung biopsy) taken from 23 patients with newly diagnosed sarcoidosis, 10 with other respiratory disease, and four patients with culture positive tuberculosis were analysed using PCR to amplify a 123 bp fragment of IS6110, the insertion element present in MTb, and nested PCR to further amplify an 85 bp sequence within the 123 bp product. DNA was also extracted from formalin fixed tissue from eight additional patients with sarcoidosis. RESULTS: MTb DNA was not detected in any of the tissue samples from patients with sarcoidosis or other respiratory disease but was found in all four patients with tuberculosis. CONCLUSIONS: This study has shown the absence of MTb DNA in lymph node and lung biopsy samples from patients with sarcoidosis. MTb is therefore unlikely to be a factor in the pathogenesis of this disease.

Nosocomial acquisition of Burkholderia gladioli in patients with cystic fibrosis.

Burkholderia gladioli has been reported as colonizing the airways of patients with cystic fibrosis (CF) but has not previously been associated with adverse outcome. We describe six patients with CF in whom the same strain of B. gladioli, on the basis of ribotyping and biochemical characteristics, was grown in their sputum. Acquisition of this organism was followed by a fatal outcome in all six patients; one had a rapid decline in respiratory status and another developed fulminant B. gladioli bacteremia. Evidence suggests that patient-to-patient transmission of the organism occurred, and supports nosocomial infection in the ward and/or outpatient clinic despite general and stringent infection-control measures. This is the first report of adverse clinical outcome following sputum colonization with B. gladioli, and the first to demonstrate person-to-person transmission.