Significance of interleukin 6 in patients with sarcoidosis

Interleukin 6 (IL-6) levels in various materials from patients with sarcoidosis were determined. The subjects of the study were 38 patients with sarcoidosis and 28 healthy controls. For detection of IL-6, an enzyme-linked immunosorbent assay method was used. Interleukin 6 activity in serum was detected in 4 of 30 patients, but not in 19 controls. In bronchoalveolar lavage (BAL) fluid, following 20-fold concentration, IL-6 activity was detected in four of ten patients (nonsmokers) and three of seven controls (two of two smokers and one of five nonsmokers). Interleukin 6 levels in the supernatants of cultured monocytes and alveolar macrophages (AMs) were significantly higher (p < 0.01 and p < 0.01, respectively) in patients with sarcoidosis than in controls. Interleukin 6 production from monocytes tended to correlate with that from AMs. A significant correlation (r = 0.70, p < 0.05) was found between IL-6 production from AMs and the ratio of CD4+/CD8+ in BAL fluid, although no correlation was observed between that from monocytes and CD4+/CD8+ ratio in BAL fluid. Taken together, IL-6 may be involved in the initiation and maintenance of alveolitis by activating and causing the proliferation of T cells.

Alveolar macrophages from patients with beryllium disease and sarcoidosis express increased levels of mRNA for tumor necrosis factor-alpha and interleukin-6 but not interleukin-1 beta

Recent evidence suggests that the alveolar macrophage-derived cytokines tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and interleukin-6 (IL-6) play important roles in granulomatous diseases. Our objective was to quantify the mRNA for these cytokines in beryllium disease, a human granulomatous disease of known etiology. We hypothesized that alveolar macrophages and bronchoalveolar lavage fluid from patients with beryllium disease and sarcoidosis would express increased levels of mRNA and proteins, respectively, for TNF-alpha, IL-1 beta, and IL-6 compared with those of normal individuals. We performed bronchoalveolar lavage and used a quantitative polymerase chain reaction to determine alveolar macrophage-derived cytokine gene expression. We determined lavage fluid cytokine levels by enzyme-linked immunosorbent assay. In patients with beryllium disease (n = 23), we observed elevated macrophage mRNA expression for TNF-alpha and IL-6 when compared with that of normal subjects (n = 7). Sarcoidosis patients (n = 6) also had increased expression for TNF-alpha and IL-6 compared with that of normal volunteers. IL-1 beta expression was similar in all three groups. In patients with beryllium disease (n = 39), lavage fluid TNF-alpha concentration was higher than that of 16 normal subjects. Lavage fluid IL-1 beta and IL-6 levels did not differ among the groups. This is the first report of macrophage cytokine expression in beryllium disease. These novel findings suggest that macrophage expression of TNF-alpha and IL-6 may be important in the human granulomatous inflammatory response.

The in vivo expression of cytokine genes in humans

We used in situ hybridization to study the expression of interleukin genes in sarcoidosis and in persistent generalized lymphadenopathy of HIV disease. In both cases, we found a dramatic over-expression of the interferon-gamma (IFN-gamma) gene as compared to that of the interleukin-2 (IL-2) gene. In sarcoidosis, IFN-gamma producing cells are CD4 T cells and are associated with IL-1 beta gene expressing monocytic cells. In HIV lympadenopathy IFN-gamma producing cells are C8 T cells engaged in cytotoxic function, as demonstrated by the concomitant expression of serine esterase B gene. Thus distinct patterns of interleukin production can be defined in vivo in selected immunopathological situations.

[IL-1, TNF and IL-6 production by alveolar mononuclear cells in patients with sarcoidosis]

Cytokines produced by locally activated T cells and macrophages have central role in lymphocyte alveolitis and granuloma formation, and it is beleived that they regulate activity and further progression of sarcoidosis. The aim of our study was to evaluate the levels of interleukin-1 (IL-1), tumor necrosis factor (TNF) and interleukin-6 (IL-6) production by bronchoalveolar mononuclear cells in 6 patients With sarcoidosis. The obtained results showed increased IL-6 levels in patients with active disease, IL-1 activity did not follow clinical changes, while TNF was detectible only in one patients.

Protein profile in bronchoalveolar lavage fluid from patients with sarcoidosis and idiopathic pulmonary fibrosis as revealed by SDS-PAGE electrophoresis and western blot analysis

So far bronchoalveolar lavage (BAL)-protein in interstitial lung disease (ILD) is evaluated by measuring concentrations of single proteins. Due to the high dilution of most proteins in BAL, analysis of protein profile has been disappointing. This study describes a new method to overcome this problem and to reveal a highly differentiated picture of BAL proteins. Eighteen patients with pulmonary sarcoidosis, 18 patients with idiopathic pulmonary fibrosis (IPF) and 22 patients with no clinical, roentgenologic or functional evidence of ILD underwent BAL. Total and differential cell count was performed. Normal values for the control group, a lymphocytic alveolitis in sarcoidosis and a granulocytic alveolitis in IPF-patients were found. Median total protein concentration in sarcoidosis showed an increase five times higher than that of the controls (150 mg 1(-1) and 27 mg 1(-1), respectively) with p < 0.001, IPF protein concentration (58 mg 1(-1)) exceeded twice the control values (0.01 > p > 0.001). Analysis of electrophoretic protein profile in controls with Western blot analysis and the biotin/streptavidin staining system revealed a highly differentiated range of bands. Staining with immunoglobulin antibody identified six bands. Four proteins with molecular weight < 21.000 dalton were present only in sarcoidosis patients. These proteins may be identical with fragmented serum proteins or different cell mediators detected in alveolar cell supernatants. Furthermore, in sarcoidosis the intensity and number of bands with molecular weight more than 67.000 dalton was increased. This gives strong evidence for an injury of the alveolar membrane integrity in the alveolitis during the course of sarcoidosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Macrophage inflammatory protein-1 alpha expression in interstitial lung disease

Mononuclear phagocyte (M phi) recruitment and activation is a hallmark of a number of chronic inflammatory diseases of the lung, including sarcoidosis and idiopathic pulmonary fibrosis (IPF). We hypothesized that macrophage inflammatory protein-1 (MIP-1 alpha), a peptide with leukocyte activating and chemotactic properties, may play an important role in mediating many of the cellular changes that occur in sarcoidosis and IPF. In initial experiments, we demonstrated that human rMIP-1 alpha exerted chemotactic activities toward both polymorphonuclear leukocytes and monocytes, and these activities were inhibited by treatment with rabbit anti-human MIP-1 alpha antiserum. In support of the potential role of MIP-1 alpha in interstitial lung disease, we detected MIP-1 alpha in the bronchoalveolar lavage fluid of 22/23 patients with sarcoidosis (mean 443 +/- 76 pg/ml) and 9/9 patients with IPF (mean 427 +/- 81 pg/ml), whereas detectable MIP-1 alpha was found in only 1/7 healthy subjects (mean 64 +/- 64 pg/ml). In addition, we found a 2.5- and 1.8-fold increase in monocyte chemotactic activity in BALF obtained from patients with sarcoidosis and IPF respectively, as compared to healthy subjects, and this monocyte chemotactic activity, but not neutrophil chemotactic activity, was reduced by approximately 22% when bronchoalveolar lavage fluid from sarcoidosis and IPF patients were preincubated with rabbit antihuman MIP-1 alpha antibodies. To determine the cellular source(s) of MIP-1 alpha within the lung, we performed immunohistochemical analysis of bronchoalveolar lavage cell pellets, transbronchial biopsies, and open lung biopsies obtained from patients with IPF and sarcoidosis. Substantial expression of cell-associated MIP-1 alpha was detected in M phi, including both alveolar AM phi and interstitial M phi. In addition, interstitial fibroblasts within biopsies obtained from sarcoid and IPF patients also expressed immunoreactive MIP-1 alpha. Minimal to no detectable MIP-1 alpha was expressed in alveolar M phi from healthy subjects or interstitial cells in lung biopsy specimens obtained from patients undergoing thoracotomy for malignancy. Furthermore, pulmonary fibroblasts isolated from patients with IPF produced greater amounts of MIP-1 alpha after challenge with IL-1 beta than did similarly treated pulmonary fibroblasts recovered from patients without fibrotic lung disease. Our findings suggest that MIP-1 alpha is expressed in increased amounts within the airspace and interstitium of patients with sarcoidosis and IPF, and that this cytokine may be an important mediator of both M phi activation and recruitment that characterize these disease states.

KL-6, a mucin-like glycoprotein, in bronchoalveolar lavage fluid from patients with interstitial lung disease

KL-6, a mucin-like high-molecular-weight glycoprotein, is a serum marker indicating the disease activity of pneumonitis, such as idiopathic pulmonary fibrosis (IPF), hypersensitivity pneumonitis, and sarcoidosis. Immunohistochemical studies have shown that KL-6 is strongly expressed on Type 2 pneumocytes and also exists on epithelial cells in other organs. It has not been clarified whether the increased levels of KL-6 in sera from patients with pneumonitis are derived from the lower respiratory tract. In this study, KL-6 levels were evaluated in bronchoalveolar lavage fluid (BALF) samples from 9 healthy control subjects and 32 patients with interstitial pneumonitis. An abnormally high level of KL-6 in BALF was observed in 70% (7 of 10) of patients with IPF, 64% (9 of 14) of patients with sarcoidosis, and 100% (8 of 8) of patients with hypersensitivity pneumonitis but in none of the healthy control subjects. KL-6 levels in BALF were significantly correlated with numbers of total cells (p < 0.001), lymphocytes (p < 0.001), and neutrophils (p < 0.05) and with concentrations of albumin (p < 0.001) and total protein (p < 0.001) in BALF and, further, with serum KL-6 levels (p < 0.01). These results indicate that increased levels of serum KL-6 in patients with pneumonitis reflect the production levels of KL-6 derived from damaged or regenerating Type 2 pneumocytes in the lower respiratory tract.

Relative release of interleukin-1 beta and interleukin-1 receptor antagonist by alveolar macrophages. A study in asbestos-induced lung disease, sarcoidosis, and idiopathic pulmonary fibrosis

We examined the influence of untreated interstitial lung disease (ILD) on the in vitro release of interleukin-1 beta (IL-1 beta) and interleukin-1 receptor antagonist (IL-Ira) from alveolar macrophages (AM); AM were harvested from normal volunteers, ILD patients, and patients with asbestos-related pleural disease but no ILD. AM were cultured for 24 h and assays for IL-1 beta and IL-1ra were done using sensitive and specific enzyme-linked immunosorbent assay. A greater amount of IL-1 beta was detected in AM supernatants from asbestosis, sarcoidosis, and IPF patients than in those from normal subjects. The IL-1 beta:IL-1ra ratio (IL-1 beta activity index [IL-1AI]) was significantly lower in supernatants of normal macrophages compared with macrophage supernatants from individuals with ILD. The IL-1AI correlated with bronchoalveolar lavage cellularity, a marker of disease activity. Current smoking was associated with lower IL-1 beta and IL-1ra release in ILD. The IL-1AI is a convenient method for comparison of IL-1 beta activity between patient populations.

Increased number of alveolar macrophages expressing surface molecules of the CD11/CD18 family in sarcoidosis and idiopathic pulmonary fibrosis is related to the production of superoxide anions by these cells

This study was designed to investigate the expression and functional properties of leukocyte adhesion molecules (LeuCAM; CD11/CD18 family) on human alveolar macrophages (AM) from patients with sarcoidosis and idiopathic pulmonary fibrosis. Cells were obtained by bronchoalveolar lavage (BAL) from 17 patients with sarcoidosis (SA), 15 with idiopathic pulmonary fibrosis (IPF), and 14 nonsmokers (NS). Expression of LeuCAM on freshly isolated cells was studied using the peroxidase-antiperoxidase method with monoclonal antibodies (MoAb) detecting CD11a, CD11b, CD11c, and CD18. The functional properties of the adhesion molecules were studied by measuring superoxide anion production (O2-) of SA and IPF AM after blocking the CD18 molecule by an MoAb. Compared with nonsmokers, the samples from SA and IPF patients contained an increased number of AM expressing CD11a, CD11b, CD11c, and CD18 (all p < 0.008), which was correlated to the number of AM/ml BAL (p < 0.008). Spontaneous O2- secretion of AM was higher in SA (6.4 +/- 1.2 nMO2-/10(6) AM/120 min) and IPF (12.0 +/- 1.1 nMO2-/10(6) AM/120 min) compared with NS (2.5 +/- 0.2 nMO2-/10(6) AM/120 min) (both p < 0.008). Incubation of the AM with the MoAb anti-CD18 reduced the spontaneous O2- release from SA AM by 52 +/- 8% and from IPF AM by 49 +/- 3% but did not influence O2- release from NS AM (92 +/- 4%). Our data indicate that the increased expression of LeuCAM on AM in subjects with SA and IPF seems to be involved in the increased O2- production of these cells in both diseases.

Identical expression of ELAM-1, VCAM-1, and ICAM-1 in sarcoidosis and usual interstitial pneumonitis

Extravasation of leucocytes in tissues is mediated by leucocyte-endothelial cell interactions in which adhesion molecules play an important role. Until now, two pathways have been unravelled, i.e., the LFA-1/ICAM-1 and the VLA-4/VCAM-1 pathways. ELAM-1 has been shown to be involved in granulocyte accumulation and recently also in lymphocyte migration. The role of HECA-452 is under investigation. In this study we have investigated the expression of the above-mentioned adhesion molecules in lung tissue of patients with pulmonary sarcoidosis and usual interstitial pneumonitis (UIP), and in mediastinal lymph nodes of patients with sarcoidosis. ICAM-1 (CD54) was broadly distributed on the endothelium of all the vessels found in sarcoidosis and UIP. VCAM-1 was present on the endothelium of the venules, capillaries, and arterioles in both sarcoidosis and UIP. ELAM-1 reacted with endothelial cells lining venules and capillaries in chronic progressive sarcoidosis and in the active phase of UIP but not in the stationary phases of both diseases. HECA-452 activity could be detected only on high endothelial venules within sarcoid lymph nodes. In lung tissues, macrophages bearing the ICAM-1 antigen were present in sarcoid tissue but not in the interstitium and alveolar space of UIP. LFA-1 (CD11a/CD18) and VLA-4 (CD49d/CD29) were present on all leucocytes found but seemed to be more highly expressed on lymphocytes in sarcoidosis. These findings suggest that the LFA-1/ICAM-1 and VLA-4/VCAM-1 pathways are involved in leucocyte migration in both types of lung disease, while in the active phases of sarcoidosis and UIP, ELAM-1 is also involved.

Increased calcium intake does not suppress circulating 1,25-dihydroxyvitamin D in normocalcemic patients with sarcoidosis

Ca absorption is regulated by 1,25(OH)2D, and serum values vary inversely with Ca intake. In sarcoidosis, 1,25(OH)2D is produced by alveolar macrophages in response to gamma-interferon, and patients may develop hypercalcemia after prolonged exposure to sunlight and increased dermal production of vitamin D3. To determine if increased Ca intake suppresses serum 1,25(OH)2D in normocalcemic patients and to identify those at risk, 17 normal subjects and 11 patients were studied on a metabolic ward for two and one-half days while receiving first 400 and then 1,000 mg/d of Ca. On the low Ca intake, serum angiotensin-converting enzyme (ACE), an index of disease activity, was higher in only three of the patients than in the controls, mean serum 1,25(OH)2D was higher in the patients, and mean serum total Ca, serum Ca++, and urinary Ca were not different in the two groups. On the higher Ca intake, mean urinary Ca increased in both groups, but mean serum 1,25(OH)2D was suppressed only in the normal subjects. Thus, 1,25(OH)2D production is abnormally regulated, indicating that (a) normocalcemic patients with sarcoidosis are at risk for developing abnormal Ca metabolism, and (b) a better index of disease activity is provided by the oral Ca suppression test than by serum ACE.

Increased secretion of tumor necrosis factor-alpha, interleukin-1-beta, and interleukin-6 by alveolar macrophages from patients with sarcoidosis

BACKGROUND

Alveolar macrophages from patients with sarcoidosis were analyzed for their ability to secrete tumor necrosis factor-alpha (TNF-alpha), interleukin-1-beta (IL-1-beta), and interleukin-6 (IL-6).

RESULTS

Constitutive release of all three monokines in these patients was concomitantly increased in the active state of disease in comparison with inactive sarcoidosis or healthy control subjects. Alveolar macrophages from patients with inactive sarcoidosis compared with cells from healthy subjects showed increased spontaneous secretion of TNF-alpha and IL-6 only, whereas the constitutive release of IL-1-beta was similar as in healthy volunteers. In vitro stimulation of alveolar macrophages from healthy control subjects with lipopolysaccharide or pokeweed mitogen led to a time- and dose-dependent enhanced secretion of TNF-alpha, IL-1-beta, and IL-6. In a similar manner, with corresponding cells from patients with sarcoidosis the secretion of all three cytokines could be further increased by stimulation with lipopolysaccharide or pokeweed mitogen.

CONCLUSIONS

The data presented indicate that an increased release of TNF-alpha, IL-1-beta, and IL-6 correlates to disease activity and may play a critical part in the pathogenesis of sarcoidosis.

Concomitant modulation of serum-soluble interleukin-2 receptor and alveolar macrophage interleukin-2 receptor in sarcoidosis

Interleukin-2 receptor (IL-2R) expression on bronchoalveolar lavage (BAL) cells was studied in patients with sarcoidosis using immune cytochemistry and cytometric analysis. A low percentage of alveolar lymphocytes (AL) was found positive for IL-2R, with 7% in patients with impaired lung function and 6% in patients with normal lung function (0.4% in control subjects). Expression of IL-2R on alveolar macrophages (AM) was considerably higher, with 25% in patients with lung function impairment compared with 14% in patients without lung function impairment (1.5% in control subjects). Serum-soluble IL-2R (ssIL-2R) was significantly elevated only in patients with impaired lung function (140.0 pM), but not in patients with normal lung function (52.2 pM; control subjects, 40.0 pM). These elevated levels of ssIL-2R positively correlated with the percentage of IL-2R positive AM (p < 0.001). Immunosuppressive treatment in three patients resulted in a decrease of IL-2R+ AM and in a decrease of ssIL-2R, whereas IL-2R+ AL were unaffected. The positive correlation and the concomitant decrease of IL-2R+ AM and ssIL-2R are consistent with the idea that in sarcoidosis with clinically apparent lung involvement, elevated levels of ssIL-2R may be derived from AM and may thus be a useful indicator of the degree of activation of these cells.

Gastrin-releasing peptide-like immunoreactive substance in bronchoalveolar lavage of idiopathic pulmonary fibrosis and sarcoidosis

The neuropeptide gastrin releasing peptide (GRP) is present in the lung, and functions as a modulator of tissue growth and repair in fibrotic processes, or as a modulator of cell movement and differentiation in various inflammatory processes, including granulomatous ones. In idiopathic pulmonary fibrosis (IPF), changes in the bronchoalveolar lavage (BAL) content of GRP can be expected. We measured GRP-like immunoreactive substances (GRP-IS) and another neuropeptide, vasoactive intestinal peptide (VIP)-IS in BAL by enzyme immunoassay. Our results showed a decrease in BAL GRP-IS in patients with IPF (26.5 +/- 5.5 pg.mg-1 protein) and sarcoidosis (35.9 +/- 9.2 pg.mg-1), compared to healthy nonsmokers (63.4 +/- 9.0 pg.mg-1). When data were expressed as pg.ml-1 BAL fluid recovered, a decrease was only seen in IPF, not in sarcoidosis. The levels of VIP-IS in BAL were not different between the groups studied. Increased protein levels in BAL had no correlation with the levels of GRP-IS or VIP-IS in BAL. Furthermore, BAL neutrophil percentages had no correlation with the levels of GRP-IS in BAL of patients with IPF. Using reversed phase high performance liquid chromatography (HPLC), several kinds of GRP-IS were detected in BAL. These findings suggest that the decreased level of GRP-IS in BAL may reflect a loss of GRP-producing cells due to chronic lung injury and fibrosis in patients with IPF.

Bronchoalveolar lavage fluid proteins in human lung disease: analysis by two-dimensional electrophoresis

Proteins of human bronchoalveolar lavage fluids, obtained by washing the epithelial lining fluid of the lungs with phosphate-buffered saline, were analyzed by two-dimensional electrophoresis under denaturating and reducing conditions. The two-dimensional pattern of bronchoalveolar lavage fluid proteins of healthy volunteers (controls) were compared with those of patients with idiopathic pulmonary fibrosis, sarcoidosis, and asbestosis. Particular interest was paid to the proteins present in minor amounts mainly in the low molecular weight region of the gels. Marked changes in single protein spots were observed. In idiopathic pulmonary fibrosis the spot intensity of the surfactant-associated protein, SP-A, showing isomeric forms both in charge and in molecular weight, was markedly decreased. In sarcoidosis, the immunoglobulins (IgG, IgA) and a group of protein spots at an isoelectric point of 4.5-5.0 and a molecular mass of 55 kDa were increased. An additional spot appeared at an isoelectric point of 4.5 and a molecular mass of 12 kDa. In particular in asbestosis, but also in some cases of idiopathic pulmonary fibrosis and sarcoidosis, the number and intensity of low molecular weight proteins were increased strongly.

[Studies on the responsiveness of alveolar T cells to proliferative stimuli and on surface antigens]

Lymphocyte alveolitis which can be detected by bronchoalveolar lavage is a characteristic feature of pulmonary sarcoidosis and has been thought to be a latent or preceding pathogenetic process of granuloma formation in the lung. To explore the mechanism of this lymphocyte accumulation, the capacity of alveolar T cells obtained from patients with pulmonary sarcoidosis to release interleukin-2 (IL-2) was assessed and compared with that of autologous peripheral blood T cells. Contrary to previous reports, spontaneous production of IL-2 by unstimulated alveolar T cells was not observed. When stimulated with phytohemagglutinin (PHA), alveolar T cells released considerable amounts of IL-2, however, still less than blood T cells. We next measured intracytoplasmic free calcium ion concentrations ([Ca2+]i) which are intimately related to cell activation triggered by proliferative stimuli. Alveolar T cells in patients with pulmonary sarcoidosis showed lowered responses of [Ca2+]i than blood T cells when stimulated with PHA, thus, demonstrating PHA-hyporesponsiveness at the second messenger level. Meanwhile, [Ca2+]i response of alveolar T cells stimulated with anti-CD3 antibody was higher than that of blood T cells. To investigate mechanisms underlying this unique responsiveness of alveolar T cells, we first examined cell surface expression of alpha beta T cell receptor (TCR). Flow cytometric analysis showed reduced expression of TCR by alveolar T cells compared with blood T cells, a phenomenon commonly called modulation. Since modulation of TCR/CD3 molecular complex is reportedly associated with T cell hyporesponsiveness to lectins, modulation appeared to account, in part, for the reduced IL-2 release by PHA-stimulated alveolar T cells. On the other hand, the present study revealed that memory T cells were dominant among alveolar T cells. This fact also seemed to be responsible for contrasting responses of [Ca2+]i to PHA and anti-CD3 antibody mentioned above, since mitogenic response of memory T cells coincide well with [Ca2+]i response of alveolar T cells. Interestingly and importantly enough, both modulation and memory T cell-dominancy in alveolar T cells were also observed in normal subjects. Accordingly, these findings suggest that responsiveness of alveolar T cells to mitogenic stimuli observed for patients with sarcoidosis is a feature shared by alveolar T cells in health and disease. Thus, present study revealed characteristics of alveolar T cells in general taking advantage of investigation of IL-2 production by alveolar T cells in sarcoidosis.

Alveolar immune mediators in HIV-related pneumonia. Different role of IL-2 and IL-1 in inducing lung damage

In order to elucidate the role played by alveolar cytokines in the pathogenesis of HIV-related lung damage, levels of interleukin (IL) 1 beta, IL-2, IL-6, tumor necrosis factor (TNF)-alpha, and interferon (Ifn) were assessed on supernatant of bronchoalveolar lavage fluid from 30 consecutive HIV-1 seropositive (HIVAb+) patients with clinical and radiologic evidence of pneumonia, from 20 HIV- seronegative (HIVAb-) patients with pulmonary sarcoidosis, and from 10 HIVAb- healthy control subjects. Cytokine levels were expressed as picogram (IL-1, TNF), nanogram (IL-6), and international unit (IL-2, Ifn) per milligram of albumin per deciliter. Total and differential cell counts, cytofluorimetric enumeration of CD3+, CD3+/DR+, CD4+, CD8+, and CD8+/CD16+ cells, as well as microbiologic investigations for opportunistic agents were performed on lavage pellets. HIV-related pneumonia was characterized by higher mean alveolar level of IL-2 (12 +/- 5 IU), and by more elevated mean counts of T cells (109 +/- 16), activated T cells (60 +/- 12), and CD8+ cells (90 +/- 13)/microliters if compared with both active sarcoidosis and control subjects, where respective values of 0.2 +/- 0.1 and 0.3 +/- 0.2 IU IL-2/mgAlb/dl, of 52 +/- 11 and 7 +/- 2 T cells, of 20 +/- 5 and 1.2 +/- 0.3 activated T cells, and of 11 +/- 2 and 3 +/- 0.6 CD8+ cells per microliter were found. HIV-infected patients with opportunistic lung infections (OIs) showed the highest mean IL-2 level (21 +/- 4 IU), and higher counts of both CD8+ (117 +/- 20) and CD8+/CD16+ (36 +/- 7) cells per microliter if compared with patients without evidence of OIs (respectively, 62 +/- 13 CD8+ and 18 +/- 3 CD8+/CD16+ cells per microliter). By contrast, extremely high IL-1 levels (1,463 +/- 760 pg), and IL-2 levels similar to control subjects (3.4 +/- 1.2 IU), were found in the absence of OIs. Different mechanisms depending respectively on IL-2-mediated cytotoxic cell recruitment and activation, or IL-1-mediated tissue injury may account for HIV-related lung damage, depending on the presence or absence of opportunistic agents.

Bronchoalveolar lavage. Quantitation of intraalveolar fluid?

A precise calculation of the amount of intraalveolar fluid is the basis of a quantitative analysis of intraalveolar compounds. Different approaches have been made to cover this important problem. Here, we report a comparative study with five markers: 99mTc-DTPA, 51Cr-EDTA, inulin, urea, and methylene blue in animal experiments as well as in human experiments. The marker substances were added to the lavage fluid, and the "dilution" of the markers, i.e., the alveolar fluid, was calculated. The results showed that in animals with healthy lungs the tracer methods are able to calculate amounts of intraalveolar fluid that are comparable to morphologic findings. In animals as well as in humans, methylene blue and inulin were shown to be useless in determining alveolar fluid volume compared with the tracer methods. In humans, the calculations with the urea method and with Tc-DTPA were in the same magnitude, but there was no individual correlation. We conclude that, at present, the methods to quantitate alveolar fluid volume lack precision and add nothing to a deeper understanding of alveolar biology.

[Serum and urinary neopterin levels in sarcoidosis]

Serum and urinary neopterin levels were determined by high pressure liquid chromatography in 26 patients with pulmonary sarcoidosis and 12 healthy controls. Neopterin levels were significantly higher in sarcoidosis patients than in the controls. Neopterin levels differed from serum angiotensin converting enzyme (ACE) activities and were significantly higher in radiologic stage 1 and 2 than in radiologic stage 0 in patients not receiving prednisolone. No significant correlation was found between neopterin level and serum ACE activity. On the other hand, a significant correlation was found between neopterin level and serum adenosine deaminase activity. We believe that serum and urinary neopterin levels may be a more clinically valuable method of assessing pulmonary sarcoidosis than serum ACE activity.

[Alveolar macrophages and granuloma formation]

We measured intracytoplasmic free calcium ion concentration ([Ca3+]i) of alveolar macrophages (AMs) in order to elucidate the mechanism(s) of lipopolysaccharide (LPS)-hyperresponsiveness of AMs in patients with sarcoidosis at the second messenger level. Resting [Ca2+]i was higher in patients with sarcoidosis than in normal subjects. [Ca2+]i increase responses were also elevated in patients with sarcoidosis when AMs were stimulated with either anti-CD14 (a LPS/LPS-binding protein complex receptor) antibody, anti-CD64 (Fc gamma receptor I), antibody or platelet activating factor. After incubation with interferon-gamma, resting [Ca2+]i and increase in [Ca2+]i induced by anti-CD14 antibody stimulation were higher in patients with sarcoidosis as compared with values before incubation. Thus, these data suggest that activation of AMs at the second messenger level induced by IFN gamma, at least in part, accounts for LPS-hyperresponsiveness in sarcoidosis.

[Diversity of T-cell antigen receptor response in individuals with sarcoidosis]

T-lymphocytes recognize specific antigen(s) through T-cell antigen receptors (TCRs). There are two classes of TCRs: those composed of alpha beta chain dimers and those formed by gamma delta dimers. Although the pathogenesis of sarcoidosis is still unclear, participation of exogenous antigen(s) is highly suggested. To investigate the mechanism of activation and accumulation of T-lymphocytes at the sites of disease, the bias of TCRs in individuals with sarcoidosis was evaluated with respect to several points. Eighteen of 51 cases of sarcoidosis showed increase of gamma delta-TCR positive T-lymphocytes in the blood. In contrast to the blood, a low number of gamma delta T-cells and evidence of T-cell stimulation through alpha beta-TCR were observed in the lung. The TCR junctional regions of V gamma 9, V delta 2 and V beta 8 gene segments were sequenced from blood and lung T-cells of individuals with sarcoidosis and normal subjects, using RT-PCR. In normals, a huge diversity of the junctional region sequences was observed in V gamma 9, V delta 2 and V beta 8 transcripts in the blood and lung. In contrast to normal subjects, a subgroup of sarcoidosis showed an increase of V gamma 9 transcripts sharing identical sequences. Although less marked than for V gamma 9, an increase in identical junctional region sequences was also observed in V delta 2 transcripts. All junctional region sequences of V beta 8 transcripts in the blood and lung were unique, indicating polyclonal activation of T-cells through TCR beta-chain.(ABSTRACT TRUNCATED AT 250 WORDS)