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Abstract Background About 30% of the population worldwide are infected with the protozoan parasite Toxoplasma gondii. Latent toxoplasmosis has many specific behavioral and physiological effects on the human organism. Modified reactivity of the immune system has been suggested to play a key role in many of these effects. For example, the immunosuppression hypothesis explains the higher probability of the birth of male offspring observed in Toxoplasma-positive humans and mice by the protection of the (more immunogenic) male embryos against abortion. Methods Here we searched for indices of immunosuppression in Toxoplasma-positive subjects by comparing clinical records of immunology outpatients. Results Our cohort study showed that the male patients with latent toxoplasmosis had decreased and the Toxoplasma-positive women had increased leukocyte, NK-cell and monocyte counts in comparison with controls. The B-cell counts were reduced in both Toxoplasma-positive men and women. The difference between Toxoplasma-positive and Toxoplasma-negative subjects diminished with the decline of the specific Toxoplasma antibody titre (a proxy for the length of infection), which is consistent with the observed decreasing strength of the effect of latent toxoplasmosis on human reproduction. The prevalence of toxoplasmosis in 128 male patients was unusually low (10.9%) which contrasted with normal prevalence in 312 female patients (23.7%) and in general population Prague (20-30%). Conclusions Latent toxoplasmosis has immunomodulatory effects in human and probably protects men against some classes of immunopathological diseases. The main limitation of the present study was the absence of the data on the immunoreactivity of immune cells subpopulations. Therefore further studies are needed to search for indices of immunosuppression in human using more specific markers.

Background: Bronchoalveolar lavage (BAL) has been widely accepted as a routine procedure in the differential diagnosis of respiratory diseases in adults. However, there is only limited information about the value of BAL in children and there is no standardisation of the procedures.Methods: The difference in cellular profiles of sequential BAL fractions from children was analysed to assess the effect of evaluating bronchial and alveolar fractions separately. Twenty five children (mean age 13.4 years) were examined by fibreoptic bronchoscopy under general anaesthesia, combined with local application of lignocaine. The investigation was part of the clinical evaluation of an infective pulmonary problem. Bronchoalveolar lavage was performed from the right middle lobe using four 20 ml aliquots of normal saline and the four fractions of recovered fluid were evaluated separately.Results: The total cell count was lowest in the first aspirate (1.8 x 10(6)) and increased gradually from fraction 1 to fraction 4. Similarly, the viability of the cells was lowest in fraction 1 and gradually improved from fraction 1 to fraction 4. In the differential count the number of neutrophils decreased from fraction 1 (8.3%) to fraction 4, with fractions 2 (5.4%), 3 (3.4%), and 4 (2.4%) being significantly different from fraction 1. There were no differences in the numbers of eosinophils, lymphocytes, or macrophages between individual fractions.Conclusions: These results show that the cell profile of the first "bronchial" fraction is different from subsequent samples. It should be evaluated separately while the second and third aliquots may be pooled. [ABSTRACT FROM AUTHOR]

Abnormal immune functions of polymorphonuclear (PMN) cells occur in a variety of pathophysiological conditions. There exists a close link between glucose metabolism and PMN functions. The aim of this study was to assess the effect of short-term hyperglycemia and/or hyperinsulinemia on phagocytosis and respiratory burst of PMN cells in healthy subjects in vivo. The study was performed on 12 healthy subjects (mean age, 26.9+/-1.6 years; body mass index, 24.4+/-0.84 kg/m(2)). Acute hyperglycemia and/or hyperinsulinemia was induced by three 4-hour-long clamp studies-hyperglycemic hyperinsulinemic clamp (HHC), hyperinsulinemic euglycemic clamp (HEC), and isolated hyperglycemic clamp with insulin secretion blockade (HGC). Polymorphonuclear cell phagocytosis and PMN cell respiratory burst (mean percentage and mean fluorescent intensity of phagocyting/activated PMN cells, phagocytic, and respiratory burst indexes) were evaluated by flow cytometry under basal and stimulated conditions. Results detected during clamp studies were compared with those found during a control study with saline infusion. Significant reductions in the mean percentage of phagocyting cells measured under basal conditions after the HHC (6.7%+/-1.3% vs 12.1%+/-4.3%; P<.05) and HGC (4.5% +/-1.8% vs 9.9%+/-2.1%; P<.05) were found in comparison with the pre-clamp study period; however, these results did not differ significantly from those detected during the control clamp (CC) study. Significantly higher phagocytic (115.1+/-65 vs 35.8 +/-18.6; P<.05) and respiratory burst indexes (16.5+/-3 vs 10.1+/-1.4; P<.05) measured under basal conditions were found after HEC in comparison with the pre-clamp data. However, these data did not differ significantly from those found after the CC study. No significant differences in other parameters of detected PMN cell immune functions were found after HHC, HEC, and HGC. In conclusion, immune functions of PMN cells were not significantly influenced by short-lasting hyperglycemia and/or hyperinsulinemia induced in vivo by clamp techniques in healthy subjects compared to changes induced by the CC study. Further studies on the short-term effect of glucose metabolism on PMN functions in diabetic patients should be considered necessary.

IL-18 is a multifunctional cytokine that augments both innate and acquired immunity and potentiates Th1 and Th2 reactions. We studied the expression of IL-18 receptor (IL-18R) on renal and respiratory epithelial cell lines. Both cell lines upregulated IL-18R mRNA and IL-18R membrane expression in response to TNF alpha and other proinflammatory cytokines. The function of IL-18R was confirmed by induction of IL-8 release from epithelial cells in response to recombinant IL-18. Epithelial cells may represent an important target for IL-18, mainly under inflammatory conditions associated with TNF alpha release.

Improvements in immunosuppressive therapy during the past decade brought about improvements of the long term tolerance of organ allografts. However, the long-term immunosuppressive therapy has an important limitation, because it can increase the risk of cardivascular diseases, infections and tumors. As compared with age-matched healthy population, organ-transplant recipients have an increased incidence of tumors.

As an autoimmune disease, type 1 diabetes mellitus (DM) can be associated with other autoimmune disorders. The aim of this study was to detect subclinically associated autoimmune thyroid disease, coeliac disease, and Addison's disease. The presence of autoantibodies was evaluated with special regard to the control of diabetes and to the clinical status of the patient. Fifty-one type 1 diabetic patients (22 men, 29 women, mean age 37+/-11 years, mean duration of diabetes 16+/-13 years) were included into this study. Specific antibodies to islet antigens--glutamic acid decarboxylase (GAD65), protein thyrosine phosphatase IA-2alpha, and to thyroid autoantigens--thyroid microsomal peroxidase (TPO) and thyroglobulin (TG) and also thyroid stimulating hormone (TSH) were measured by RIA. Autoantigens of the small intestine--tissue transglutaminase autoantibodies (ATTG), IgA and IgG antibodies to gliadin (AGA-IgA, AGA-IgG) were evaluated by ELISA. Endomysial autoantibodies (EMA) and adrenal cortex antibodies (ACA) were detected by indirect immunofluorescence microscopy. Eleven new cases of thyreopathy (22 % of patients) were detected by the assessment of thyroid autoantibodies and TSH. Two new cases of thyreotoxicosis were diagnosed during the study. Coeliac disease was diagnosed in at least two cases. Addison's disease was not diagnosed, although the ACA were positive in two patients. No influence of single or combined autoantibody positivity on the control of diabetes was found if normal organ function was preserved. In both patients with thyreotoxicosis the control of diabetes was worsened and improved after treatment. The screening of autoantibodies in type 1 diabetic patients could reveal subclinical cases of AITD or coeliac disease. Subclinical forms of these disorders have no influence on diabetes control. However, impaired organ function may be associated with the worsened control of diabetes as we demonstrated on two newly diagnosed cases of thyreotoxicosis. We suggest the need for the follow-up of patients with positive autoantibodies because further deterioration of the respective organs can be expected.

Calprotectin (MRP8/14, S100A8/S100A9, 27E10 antigen) is a heterodimer of two calcium-binding proteins present in the cytoplasm of neutrophils and expressed on the membrane of monocytes. Upon neutrophil activation or endothelial adhesion of monocytes, calprotectin is released and may be detected in serum or body fluids as potentially useful clinical inflammatory marker. The soluble form of calprotectin provides both bacteriostatic and cytokine-like effects in the local environment. When calprotectin metabolism is affected on a systemic level, the zinc-binding properties of protein may induce severe dysregulation of zinc homeostasis with severe clinical symptoms. The distribution of membrane form of calprotectin is restricted to monocytes and immature macrophages and the presence of calprotectin-positive infiltrating cells reflects the influx of mononuclear phagocytes to the site of inflammation. Calprotectin expression and release seems to be of particular importance in immune and immunopathological reactions.

Recent literary data suggest that antibodies to HLA antigens undetectable by the standard complement-dependent cytotoxicity test may cause not only chronic, but also acute immunological complications after kidney transplantation. The aim of this study was to investigate the significance of non-cytotoxic antibodies to HLA antigens for the development of immunological complications and a worse graft prognosis after first kidney transplantation. Sera before and early after transplantation from 120 first kidney recipients were analyzed by flow cytometry (FCXM), ELISA and the standard complement-dependent cytotoxicity (CDC) test. Pre-transplant FCXM negativity was related to a lower incidence of rejection episodes in the first post-transplant year ( P<0.01). A significant association between acute rejection and the presence of antibodies to HLA class II antigens before and after transplantation was also found ( P<0.05). Our study supports the findings of other centers of the detrimental role to the kidney graft played by anti-HLA antibodies undetectable by the classical CDC test.

Chronic allograft nephropathy (CAN) represents a frequent and irreversible cause of long-term renal graft loss. TGF-beta1 is a key profibrogenic cytokine associated with CAN pathogenesis. Because of clinical diagnostic inaccuracy, protocol biopsy has been suggested to be a beneficial method for early CAN detection. Protocol core biopsy was carried out in 67 consecutive cyclosporine-based immunosuppression-treated kidney transplant recipients with stable renal function 12 months after renal transplantation. Biopsy specimens were analyzed morphologically according to Banff-97' criteria and immunohistologically for TGF-beta1 staining. The data obtained were correlated with plasma TGF-beta1 levels and clinical data. CAN (grade I-III) was found in 51 patients (76 %). CAN grade I was found to be the most frequent one (44 %). A normal finding within the graft was made in only 12 patients (18 %). Clinically silent acute rejection Banff IA was present in 4 patients (6 %). In 8 patients (12 %) with CAN, borderline changes were present. We found a significant correlation between CAN grade and creatinine clearance, as measured by the Cockroft-Gault formula (p<0.01) as well as body mass index (p<0.01). There was a significant correlation between chronic vasculopathy (Banff cv) and creatinine clearance, and between the degree of TGF-beta1 staining and chronic vasculopathy (p<0.01). There were no relations between morphological findings and TGF-beta1 plasma levels, cyclosporine levels, plasma lipids, HLA-mismatches, panel reactive antibodies (PRA), proteinuria, and the donor's age. In conclusion, CAN is a frequent finding in protocol kidney graft biopsies 12 months after transplantation. TGF-beta1 tissue expression is linked with chronic vasculopathy.

Background: Patients with diabetes represent 50 to 70% of patients who undergo nontraumatic foot or leg amputation, caused mostly by infection and necrosis of soft tissues accompanied with osteomyelitis. Signs and symptoms of infections may often be absent in patients with infected foot ulcers--the syndrome of "diabetic foot" (DF). The course and consequences of the infection may be influenced by the immune system dysfunction. The aim of our study was to assess presence of the chronic inflammation and specific immune responses, both humoral and cellular in patients with diabetic foot infection., Methods and Results: 34 patients treated over one month for an infected DF in our foot clinic (mean age 54 +/- 8 years, mean duration of diabetes 20 +/- 9 years, mean HbAlc 8.8 +/- 1.5%), were matched with 27 healthy subjects. All patients were without clinical signs of acute deep foot infection and without critical leg ischemia. The inflammatory response was assessed by white blood cells count and C-reactive protein (CRP), humoral immune response was assessed by immunoglobulins (Ig) and cellular immunity was evaluated by T lymphocytes subpopulations. Patients with DF compared with healthy controls exhibited the laboratory signs of infection--significantly increased white blood cells count (7.6 +/- 2.1 vs. 6.4 +/- 1.3.10(9)/l, p < 0.01) and neutrophil count (4.6 +/- 1.8 vs. 3.8 +/- 0.9.10(9)/l, p < 0.05) and significantly increased CRP (7 +/- 12 vs. 2 +/- 6 mg/l, p < 0.01). Patients with DF had also significantly higher IgA levels (3.5 +/- 1.6 vs. 2.7 +/- 1.1 g/l, p < 0.05) and significantly more CD3+ T cells (76 +/- 8 vs. 71 +/- 10%, p < 0.05) and suppressor/cytotoxic CD8+ T cells (32 +/- 11 vs. 26 +/- 10%, p < 0.05). Other followed parameters IgG, IgM and serum monocyte and lymphocyte counts, CD4+ helper T cells and CD4+/CD8+ T-cell ratio did not differ between patients with DF and healthy controls., Conclusions: We did not anticipate a severe secondary immunodeficiency in followed cellular and humoral immune parameters in patients with chronic bacterial foot infection. It is necessary to assess the sufficiency of immune system activation with respect to chronic inflammation in next research.

Chronic bacterial ulcers infection is a frequent cause of non-healing diabetic foot. The major factors of a non-specific immune response are phagocytic cells including polymporphonuclear (PMN) leukocytes, and humoral systems (complement). PMN leukocytes remove microorganisms by phagocytosis a part of it is intracellular killing and degradation in a process requiring energy and associated with "respiratory burst". The aim of our study was to assess non-specific immune response in patients with diabetic foot syndrome and chronic bacterial infection. 30 patients treated over one month with antibiotics for an infected diabetic foot in our foot clinic had significantly lower values of "oxidative burst" of PMN leukocytes in basal state (396 +/- 228 vs. 574 +/- 337, p < 0.05) in comparison with 25 matched healthy controls. There were no significant differences neither in the count of active phagocyting PMN leukocytes and their initial phagocytic activity nor in the humoral component of non-specific immunity (in circulating immunocomplexes, C3 and C4 components of complement) between both groups. The results of our study show a slightly altered non-specific immune response in patients with diabetic foot syndrome and chronic bacterial infection.

Objectives: MRP8/14 is a heterodimer of two myeloid calcium-binding proteins associated with different types of acute inflammatory processes. We studied MRP8/14 together with procalcitonin (PCT) serum levels in order to diagnose infectious complications or the rejection process affecting kidney or heart allograft., Methods: A total of 419 serum samples was evaluated. MRP8/14 levels were measured by ELISA (BMA Biomed), PCT by a sensitive immunoluminiscent assay ILMA (Brahms Diagn.), Results: Both parameters showed very low basal levels in healthy subjects (range 303-1,660 ng/ml of MRP8/14; less than 0.08 ng/ml of PCT). A rapid increase in serum levels occurred in response to bacterial infections (MRP8/14 up to 6,230 ng/ml; PCT up to 297 ng/ml). Serum PCT concentration remained low in the presence of kidney allograft rejection, where MRP8/14 levels were increased. An uncomplicated outcome of kidney or heart transplantation did not change basal serum MRP8/14 and PCT levels., Conclusions: We conclude that 1) both MRP8/14 and PCT are very sensitive markers of complications in organ transplant recipients (normal values in uncomplicated outcome) 2) combination of both parameters is useful to discriminate between rejection (increased MRP8/14 with normal PCT) and systemic bacterial infection (both parameters increased).

Objective: The aim of this study was to characterize patient antibodies before and after cadaver and/or living-donor kidney transplantation and to correlate these data with the clinical course after transplantation., Methods: Sera from 69 cadaver, 9 living-related and 2 patients waiting for living-donor kidney transplantation were analyzed by the complement dependent cytotoxicity (CDC) test, flow cytometry (FCXM) and ELISA., Results: FCXM revealed that 15.0% of patients before transplantation and 16.7% after transplantation had antibodies to donor cells. 10.3% patients were positive before and after transplantation (+/+), while 6.8% developed antibodies early after transplantation (-/+). Analysis of the specificity of those antibodies by ELISA showed that it was directed to: 1) mismatched donor HLA antigens 2) antigens belonging to the same cross-reacting group (CREG) as the mismatched donor antigens 3) HLA antigens not expressed by donor cells or, probably, to non-HLA antigens., Conclusion: Anti-HLA antibodies were detected in patients before and after transplantation and in most cases their anti-HLA specificity could be determined. Fast and precise characterization of antibodies in patients before and after transplantation can be performed by both sensitive methods--FCXM and ELISA--which may help predict the onset of immunological complications and, consequently, improve the prognosis after organ transplantation.

Human bronchial epithelial cells are involved in airway immune mechanisms through secretion of cytokines and through cell-cell contacts with immunocompetent cells. The aim of our study was to assess the ability of interferon (IFN) alpha and gamma alone and in combination to modulate human bronchial epithelial cell (HBECs) release of the inflammatory cytokines IL-8 and IL-6 and fibronectin and to induce the surface expression of HLA-DR and ICAM-1 molecules involved in immune interactions with other cells. HBECs spontaneously secreted a limited amount of IL-8, which was significantly increased by IFN gamma. IFN alpha inhibited IFN gamma stimulated IL-8 secretion in a concentration-dependent manner. Further, IFN gamma induced IL-6 and fibronectin secretion, and this was also inhibited by IFN alpha. The expression of HLA-DR antigens was significantly increased by IFN gamma and partially inhibited by co-stimulation with IFN alpha. In contrast, IFN gamma also induced ICAM-1 expression by HBECs but co-stimulation with IFN alpha had no significant effect on the expression of this surface antigen. IFN alpha modulation of HBEC functions does not seem to be restricted to IFN gamma stimulation since either stimulatory or inhibitory effects of INF alpha on IL-8 production have been found in pilot experiments using IL-1 beta, TNF alpha, and TGF beta as stimuli. In summary, IFN-gamma induces a number of responses in HBECs including increased secretion of IL-6, IL-8 and fibronectin and increased expression of HLA-DR and ICAM-1. IFN alpha can inhibit all these except expression of ICAM-1 which is unaffected. IFN alpha can also interact with other inflammatory cytokines, but whether the effects are inhibitory or augmentive depends on the cytokines.

Cytokine networks are important in regulating the traffic of inflammatory cells in the airways. Interleukin-8 (IL-8) released by human bronchial epithelial cells (HBECs) is thought to be of particular importance in attracting neutrophils and monocytes to sites of inflammation. Increased release of IL-8 by HBECs in response to Th-1 cytokines such as TNF alpha and IL-1 beta may be an important pathophysiologic pathway. The present study was designed to explore the role of the Th2 cytokine IL-4 and the functionally related interleukins IL-10, and IL-13 on the regulation of IL-8 release by HBECs. HBECs (passage 4-6) were cultured in LHC9/RPMI and when confluent cells were stimulated in unsupplemented medium LHCD/RPMI by IL-4, IL-10, and IL-13 at 10 ng/ml concentration for all cytokines. TNF alpha stimulation was used as a positive control. After 24 hours supernatants were collected and tested for IL-8 by a sandwich ELISA. Unstimulated HBECs spontaneously released limited amounts of IL-8 (11 +/-1 pM) and significantly increased cytokine production in response to IL-4 (42 +/- 1 pM), IL-13 (30 +/- 1 pM) and TNF (128 +/- 11 pM). Stimulation with IL-10 (11 +/- pM) did not change basal production of IL-8. When HBECs were co-stimulated with IL-4 plus TNF, the production of IL-8 was further increased (204 +/- 5 pM). In contrast, IL-10 attenuated the effect of TNF during co-stimulation (82 +/- 5 pM). IL-13 did not affect the release of IL-8 induced by TNF (111 +/- 9 pM). Northern blot analysis of IL-8 mRNA levels showed the highest induction of IL-8 mRNA in HBECs co-stimulated with TNF and IL-4. We conclude from our study that IL-4 directly induces IL-8 release from HBECs and amplifies the release of IL-8 in response to TNF alpha. IL-13 is less active and IL-10 has an inhibitory effect. Airway epithelial cells are able to interact, therefore, with products of both Th1 and Th2 cells with respect to modulating release of IL-8.

The multifunctional cytokine IL-6, which can be locally produced by human bronchial epithelial cells (HBECs), has been found to play a role in IL-4 dependent IgE synthesis. Since the allergic reaction in bronchial asthma is associated with the upregulation of IL-4 and Th2 type of immune response, the purpose of our study was to assess whether IL-4 and related cytokines IL-10 and IL-13 regulate IL-6 release by HBEC s. HBECs were obtained by bronchial brushing, cultured in LHC-9/RPMI 1640. At the third passage the cells were stimulated with cytokines (0.1-20 ng/ml) diluted in unsupplemented media for 24 h. The supernatants were tested for IL-6 content by sandwich ELISA. Unstimulated HBECs produced detectable amounts of IL-6 (368+/-25 pg/ml). Exposure to IL-10 (368+/-22 pg/ml) and IL-13 (395+/-6 pg/ml) resulted in little changes. IL-4 caused a slight but significant increase in IL-6 release (530+/-45 pg/ml), P<0.05, TNFalpha (1657+/-85 pg/ml) and IFNgamma (1953+/-37 pg/ml) showed strong induction of IL-6 release in HBECs (P<0.005 and P<0.001, respectively). Both IL-4 and IL-13 significantly inhibited TNF induced IL-6 release (P<0.01 for both) while augmenting the effect of IFNgamma (P<0.005 and P<0.01, respectively.). IL-10 was without a significant effect. We conclude that Th2-type cytokines IL-4 and IL-13 affect the release of IL-6 by HBECs in response to TNFalpha (inhibition) and IFgamma (augmentation). IL-10 had no effect on the regulation of IL-6 release. Modulation of IL-6 levels by Th2-type cytokines may play a role in allergic reactions through the IL-6 promoting effect on IL-4 mediated IgE production.

Alveolar macrophages (AM) originate from blood monocytes and, during the maturation process, undergo functional and morphological changes which are also reflected in their phenotypic pattern. Among the macrophage membrane antigens, adhesion molecules of the integrin family are particularly important for effector functions and cell-cell interactions. The aim of this study was to analyse the membrane expression of selected integrins by AM recovered from bronchoalveolar lavage (BAL) as compared to their precursors, peripheral blood monocytes (PBM). The cells were stained using a sensitive immunoperoxidase assay with 10 different monoclonal antibodies. The data showed a higher expression by AM than PBM of all but one of the studied adhesion molecules. The only exception was CD11b (Mac-1, CR3) which showed a higher expression in PBM than in AM. Several molecules, for example, CD49d (VLA-4), CD51 (vitronectin receptor), and CD54 (intercellular adhesion molecule-1, ICAM-1) were found to be upregulated by AM in patients with a lymphocytic pattern of BAL. In contrast, the phenotype of PBM does not show any changes in these patients. In conclusion, we have demonstrated differences in the expression of integrins between AM and PBM which can be partially responsible for some of their functional differences.

The soluble form of the leukocyte membrane antigen CD14 is known to increase the sensitivity of endothelial and epithelial cell lines to bacterial lipopolysaccharide (LPS). This molecule also directly induces cytokine production in monocytes. Here, the effect of sCD14 and LPS on the release of IL-6 and IL-8 by human bronchial epithelial cells (HBECs) was studied. Soluble CD14 induced cytokine production both in the presence and absence of LPS. In addition, neither sCD14 nor anti-CD14 monoclonal antibody which blocks the interaction of LPS with CD14 had any effect on the binding of LPS to HBECs. These data suggest that sCD14 may induce the release of IL-6 and IL-8 from HBECs. However, the binding of LPS to bronchial epithelium appears to be mediated by CD14-independent mechanisms.

The phenotype of alveolar macrophages (AMs) is known to be modulated during pathological immune reactions in the lung. In this study, we wanted to determine the relationship between the AM phenotype and changes in the proportions of the various immune cells in bronchoalveolar lavage (BAL). BAL was performed in 76 consecutive patients, including 32 with sarcoidosis, 8 with idiopathic pulmonary fibrosis, 9 with pneumoconiosis, 13 with other respiratory disorders, and 14 controls without evidence of interstitial lung disease. The phenotype of AMs was studied by a panel of 15 monoclonal antibodies against various myeloid antigens, and was correlated with the proportions of cells obtained by BAL. The percentage of BAL lymphocytes showed a relationship with the expression of macrophage antigens in 11 out of 15 antigens studied (all except adhesive molecules CD11a, CD11c, CD18 and the antigen 25F9 present on mature macrophages). Furthermore, the CD4/CD8 ratio of BAL T-lymphocytes correlated with the AM expression of CD54 (intercellular adhesion molecule-1 (ICAM-1)), RFD1 (marker of dendritic cells), and CD71 (transferrin receptor). In samples with an increased number of bronchoalveolar neutrophils, the subpopulation of 27E10 positive AMs (inflammatory acute phase macrophages) was increased. Eosinophils in BAL were not associated with a significant increase in AM membrane antigen expression. Prominent changes of the AM phenotype were found in active sarcoidosis showing lymphocytic alveolitis, with more frequent expression of CD54, KiM2, CD71, CD11b and RFD9. In conclusion, this study shows that the phenotype of AMs is related to the type and intensity of the immunopathological reaction in the lung, and correlates with the proportions of bronchoalveolar cells.

The expression of maturation-associated antigens on alveolar macrophages (AMs) was studied in bronchoalveolar fluid of 30 patients with sarcoidosis and 11 control subjects. The percent of AMs expressing CD14 or CD11b (common for blood monocytes) was significantly increased in patients with active sarcoidosis compared to those with inactive disease, and control subjects. On the other hand, the mean expression of antigens characteristic for mature macrophages showed no significant difference (25F9), or was even increased in patients with sarcoidosis (CD71, KiM8). Since CD14 and CD11b molecules were also frequently expressed on large phagocytes morphologically similar to mature macrophages, and recent studies showed modulation of these glycoproteins by the activation of myeloid cells, our data indicate that the majority of AMs recovered by bronchoalveolar lavage in sarcoidosis are mature, activated cells.