Anergy-like immunosuppression in mice bearing pulmonary foreign-body granulomatous inflammation.

Pulmonary granulomas were induced in BALB/c mice by the intratracheal injection of insoluble polymerized dextran and latex microparticles. Very large granulomas developed around dextran beads, which reached peak intensity within 2-3 days and rapidly declined in size thereafter. Latex beads generated small stable lesions. The involvement of cell-mediated immunity could not be demonstrated in the inflammatory responses induced by either type of bead. Antigen-induced delayed type hypersensitivity (DTH) and mitogen-induced DTH-like footpad reactions were markedly suppressed in immunized mice bearing early dextran granulomas. Mitogen-induced DTH-like footpad reactions were suppressed in unimmunized animals bearing early dextran foreign-body granulomas. Antigen- and mitogen-induced footpad swelling recovered to normal levels as dextran granulomas diminished in size. No suppression of these footpad reactions was observed in mice bearing small latex foreign-body granulomas. The intraperitoneal injection of aqueous extracts prepared from the lungs of unimmunized donor animals bearing early dextran foreign-body granulomas could partially transfer suppression of mitogen DTH-like footpad responses to normal mice. These results suggest that cells within large, nonimmunologic lung granulomas produce a soluble factor which participates in the expression of anergy-like immunosuppression.     

Experimental production of pulmonary granulomas; II. Age dependency and immune modulation of granuloma production.

Endobronchial instillation of Freund''s complete adjuvant (FCA) induced epithelioid cell granulomas in the lungs of juvenile rabbits which had been kept free from contamination with the microbiol antigens. The granulomas were named "juvenile granulomas", because, unlike FCA granulomas in adult animals, prior immunization was unnecessary for their induction. The granulomas developed in several weeks with a peak at 14 weeks of age, after which the production decreased gradually. The rate of granuloma production seemed to vary with the acquisition of skin hypersensitivity to tuberculin (OT), suggesting that granuloma production, as well as skin hypersensitivity, is in the category of T-dependent immune reactions. In fact, T-generating lymphoid organs developed in parallel with the dermal and pulmonary reactions. Thus, juvenile rabbits at about 14 weeks of age are most susceptible to the microbial antigens. This susceptibility results in the unexpected production of immune granulomas in response to depot antigens at the site of instillation. The treatment of foetal or neonatal rabbits with FCA markedly suppressed granuloma production in juveniles but not in adults and did suppress but gradually enhanced the tuberculin skin reaction. It is suggested that generation of suppressor T cells is the cause of suppression of juvenile granuloma production.     

Long-chain polyunsaturated fatty acids are consumed during allergic inflammation and affect T helper type 1 (Th1)- and Th2-mediated hypersensitivity differently

Studies have shown that atopic individuals have decreased serum levels of n‐3 fatty acids. Indicating these compounds may have a protective effect against allergic reaction and/or are consumed during inflammation. This study investigated whether fish (n‐3) or sunflower (n‐6) oil supplementation affected T helper type 1 (Th1)‐ and Th2‐mediated hypersensitivity in the skin and airways, respectively, and whether the fatty acid serum profile changed during the inflammatory response. Mice were fed regular chow, chow + 10% fish oil or chow + 10% sunflower oil. Mice were immunized with ovalbumin (OVA) resolved in Th1 or Th2 adjuvant. For Th1 hypersensitivity, mice were challenged with OVA in the footpad. Footpad swelling, OVA‐induced lymphocyte proliferation and cytokine production in the draining lymph node were evaluated. In the airway hypersensitivity model (Th2), mice were challenged intranasally with OVA and the resulting serum immunoglobulin (Ig)E and eosinophilic lung infiltration were measured. In the Th1 model, OVA‐specific T cells proliferated less and produced less interferon (IFN)‐γ, tumour necrosis factor (TNF) and interleukin (IL)‐6 in fish oil‐fed mice versus controls. Footpad swelling was reduced marginally. In contrast, mice fed fish oil in the Th2 model produced more OVA‐specific IgE and had slightly higher proportions of eosinophils in lung infiltrate. A significant fall in serum levels of long‐chain n‐3 fatty acids accompanied challenge and Th2‐mediated inflammation in Th2 model. Fish oil supplementation affects Th1 and Th2 immune responses conversely; significant consumption of n‐3 fatty acids occurs during Th2‐driven inflammation. The latter observation may explain the association between Th2‐mediated inflammation and low serum levels of n‐3 fatty acids.     

Eosinophilic lung disease: immunological studies of blood and alveolar eosinophils.

Five patients with eosinophilic lung diseases and blood hypereosinophilia (PIE syndrome) were investigated clinically and by bronchoalveolar lavage (BAL). Comparative studies on blood and alveolar eosinophils were carried out after purification and selection of eosinophil subpopulations according to their density. A predominant 'hypodense' alveolar eosinophil population was found in BAL fluids of active chronic eosinophilic pneumonia (CEP). In addition, supernatants of alveolar macrophages obtained from CEP are able to enhance spontaneously the generation of eosinophil oxygen metabolites. Such eosinophil stimulation emphasizes a probable tissue cell cooperation. In addition, BAL permitted the study of membrane immunological markers on eosinophilic inflammatory cells endowed with migratory properties. An increase in eosinophils carrying surface IgE was demonstrated in alveolar cells from PIE Syndrome particularly with hypodense eosinophils from CEP patients. Although no specific stimulus is known at the present time, this work underlines the potential implication of IgE-mediated hypersensitivity processes in the pathogenesis of eosinophilic lung diseases.     

The spectrum of eosinophilic infiltration of the gastrointestinal tract and its relationship to other disorders of angiitis and granulomatosis.

Six cases of eosinophilic infiltration of the gastrointestinal tract were studied. Three cases were of the diffuse infiltrative variety (eosinophilic enteritis, two cases; eosinophilic peritonitis, one case), and three cases were of the circumscribed variety (so-called inflammatory fibroid polyp). Two of the infiltrative lesions showed necrotizing granulomas identical to those described by Churg and Strauss; one of the two also showed active vasculitis. One circumscribed lesion occurred in a patient with polyarteritis nodosa. Necrotizing eosinophilic granulomas were also noted in this lesion. Our observations suggest that the two forms of eosinophilic infiltration of the gastrointestinal tract are parts of a disease spectrum. Supporting evidence in the literature is presented. The relationship of this group of eosinophilic lesions to the hypereosinophilic syndrome, allergic granulomatosis and angiitis of Churg and Strauss, and polyarteritis nodosa is discussed.     

Ultrastructural study of central nervous system demyelination in galactocerebroside sensitized rabbits

The rabbit eye model was used to investigate the role of delayed type hypersensitivity and of circulating antigalactocerebroside antibody in primary demyelination. Delayed type hypersensitivity reaction to tuberculin was induced within the retinal myelinated layers by injecting purified protein derivative into the vitreous of rabbits that were previously immunized with complete Freund's adjuvant (CFA) alone, or galactocerebroside (GC) in CFA. The morphological features of the myelinated zones were assessed 5 days after injection. All rabbits showed infiltration of mononuclear cells within the myelinated fiber bundles. Rabbits previously sensitized with CFA alone showed nonspecific destruction of nerve fibers in severe inflammatory lesions, but primary demyelination was rarely found. This suggests that myelin destruction induced by delayed type hypersensitivity reaction to interstitial antigens (purified protein derivative, so-called "bystander demyelination") by itself does not play a major role in inducing primary demyelination. On the other hand, primary demyelination was recognized in the vicinity of infiltrating mononuclear cells in rabbits previously immunized with GC in CFA and had elevated titers of serum anti-GC antibody. The destruction of the blood-brain barrier was suggested by the presence of fibrin exudates in demyelinative lesions where observation revealed selective myelin breakdown such as vesicular disruption and active stripping of myelin. This study indicates that the anti-GC antibody is an important factor in central nervous system demyelination of GC-sensitized rabbits.     

Evolution of foam cells in subcutaneous rabbit carrageenan granulomas. II. Tissue and macrophage lipid composition.

This study describes the lipid composition of differentiating macrophage-derived foam cells in the inflammatory carrageenan granuloma. In this model, macrophages exposed in vivo to diet-induced hypercholesterolemia progressively accumulate electron-translucent lipid inclusions; and at 14 and 28 days, many assume the morphologic features of arterial plaque foam cells. Subcutaneous carrageenan granulomas were induced in 24 pellet-fed (NC) and 24 cholesterol-fed (HC) rabbits, and tissue was harvested at 4, 14, and 28 days. Total (TC) and free cholesterol (FC), cholesteryl esters (CEs), CE fatty acids, triglycerides (TGs), and phospholipids (PLs) were measured on lipid extracts from tissue. TC, FC, and CEs were also measured on isolated, cultured granuloma macrophages. Tissue TCs and FCs were significantly elevated in HC relative to NC rabbits at both 14 and 28 days (P less than 0.005 and P less than 0.01, respectively). CE accumulation in HC granuloma tissue was 80-fold greater at 14 days and 178-fold greater at 28 days (P less than 0.005), compared with NC granulomas. Oleic acid (18:1), the principal CE fatty acid in both NC and HC granulomas, accounted for significantly more (P less than 0.05) of the total CE fatty acids in HC (48%) relative to NC granulomas (37%). No net accumulation of TG was observed with time in NC or HC animals. Although diet did not influence tissue PL content, significant increases (P less than 0.05) were observed at 14 days in NC rabbits and at 14 and 28 days in HC rabbits relative to 4-day levels. CE accumulation was significantly greater in cultured macrophages isolated from HC granulomas at 14 days (P less than 0.001) and 28 days (P less than 0.01). These findings have demonstrated the significant accumulation of CEs in both HC granuloma tissue and in cultured HC macrophage/foam cells in vivo. The carrageenan granuloma model has, we believe, considerable potential for defining mechanisms responsible for CE accumulation in the differentiating macrophage-derived foam cell.     

Macrophage function in the Schistosoma mansoni egg-induced pulmonary granuloma. Role of arachidonic acid metabolites in macrophage Ia antigen expression.

The ability of arachidonic acid (AA) metabolites to regulate I-region-associated (Ia) antigen expression on macrophages from schistosome-egg-induced pulmonary granulomas was examined. The prostaglandin (PG) analog 15-S-15-CH3-PGE1 (M-PGE1) and PGF2 alpha were found to modulate the kinetics of Ia expression when administered in vivo. Methyl-PGE1 significantly suppressed Ia antigen expression by hypersensitivity granuloma macrophages, while PGF2 alpha appeared to potentiate the expression. Lymphokine-induced Ia antigen expression by cultured granuloma macrophages was likewise dramatically inhibited by M-PGE1. Further analysis using systemically administered inhibitors of AA metabolism demonstrated that the cyclooxygenase inhibitor indomethacin caused augmentation of Ia expression. In contrast, lipoxygenase inhibitors significantly reduced both Ia expression and granuloma size. The role of AA metabolites in modulating chronic inflammation is discussed.     

The Pathogenesis of Leishmania aethiopica Infection in BALB/c Mice

A mouse model for L. aethiopica infection is described. BALB/c mice were unable to clear an infection with 1 x 10(7) promastigotes injected into the hind footpad. However, there was no ulceration of the lesion and no development of overt clinical symptoms after 203 days of infection. Spread of viable organisms was evident in the draining lymph node but not in the spleen or liver. The control of the infection was associated with the development of classical delayed hypersensitivity responses to phenolized promastigotes and appeared as a localized granulomtaous infiltration. The infiltration had features of classical tuberculoid granulomas, but superimposed on it was a strong eosinophilic infiltration. The relevance of such cells though unclear is discussed.     

In vivo responses to inhaled proteins. II. Induction of interstitial pneumonitis and enhancement of immune complex-mediated alveolitis by inhaled concanavalin A.

An animal model of environmental lung disease is described in which phytomitogen, antigen, or both, are administered in aerosol form to previously immunized or immunologically naive rabbits. Inhalation of concanavalin A alone induced an interstitial pneumonitis in nonimmunized rabbits. Inhalation of concanavalin A alone induced an interstitial pneumonitis in nonimmunized rabbits. Inhalation of bovine serum albumin (BSA) alone typically produced only focal eosinophilic granulomas in BSA-immunized animals, and no injury whatever in nonimmune animals. However, simultaneous administration of BSA-concanavalin A aerosol mixtures to BSA-immunized rabbits induced a severe interstitial pneumonitis and granulomatous vasculitis, together with areas of frank parenchymal necrosis. When repeated on a chronic basis over a 4- or 8-week interval, challenge with BSA-concanavalin A aerosols resulted in both acute necrotic lesions as well as areas of frank interstitial fibrosis. Necrotic foci in acutely injured lungs were associated with interstitial deposits of BSA, rabbit anti-BSA antibody, and complement. Electron microscopy revealed numerous neutrophils within the pulmonary interstitial spaces of these animals, often in association with collagen and elastin fibers. The pattern of injury in immune rabbits induced by antigen-concanavalin A aerosols, in its nonnecrotizing form, is consistent with that of an extrinsic allergic alveolitis. However, the severe, necrotizing form of acute injury closely resembles changes seen in Wegener's granulomatosis. Possible mechanisms of injury produced by antigen and phytomitogen inhalation are discussed.     

Allergic granulomatosis secondary to a limited form of Churg-Strauss syndrome.

Allergic granulomatosis is a disorder of obscure etiology characterized by infiltration of lymph nodes with histiocytic granulomas and eosinophils. In this report, we describe a case of allergic granulomatosis that is consistent with Churg-Strauss disease limited to lymph nodes. The histologic findings of this patient's lymph nodes demonstrated eosinophilic abscesses and ring-shaped necrotizing and nonnecrotizing granulomas surrounding hyperplastic germinal centers. We report herein a rare type of reactive lymphadenopathy and present its histologic, immunohistochemical, and flow cytometric findings, which may allow its distinction from other lymphadenopathies.     

Studies of sperm antigenicity. 6. In vivo and in vitro cellular reactivity in guinea pigs sensitized with fractions of guinea pig spermatozoa.

Normal guinea pig spermatozoa cells were homogenized by a French pressure cell. Three soluble and three insoluble fractions were obtained by ultrascentrifugation and (emulsified in CFA) were used for guinea pig sensitization. The following were observed: 1) all fractions were immunogenic except one; 2) in vivo and in vitro delayed hypersensitivity was elicited in animals immunized with these fractions; 3) two distinctive histopathologic lesions were observed in the testes of sensitized animals: lesions of orchitis type developed in animals injected with some fractions. Other fractions induced lesions of aspermatogenic type. These results correlated well with delayed hypersensitivity results obtained by in vivo and in vitro tests. Although some other spermatozoal fractions did not cause severe changes in the testes. The lack of sperm accumulation in the epididymis was obvious.     

Fat metabolism in brown adipose tissue in vivo

1. Noradrenaline infusions (I.V. for 30 min) in new-born and 1-week-old unanaesthetized rabbits caused a rapid and sustained rise in oxygen consumption and an increase in blood glucose, free fatty acid and glycerol concentrations. Similar changes occurred in anaesthetized 1-week-old rabbits.2. A simple direct method was used to measure the net exchange of metabolites across brown adipose tissue in anaesthetized young rabbits. It was found that the brown adipose tissue of rabbits reared from birth in a thermoneutral environment and studied when their next feed was due took glucose from and released fatty acids and glycerol into the circulation.3. Similar rabbits kept unfed for a further 48 hr in a warm environment released fatty acids and glycerol from their brown adipose tissue at a far greater rate, but the rate of glucose uptake was reduced.4. On the other hand the brown adipose tissue of rabbits kept unfed in a cold environment (20 degrees C) took up circulating free fatty acids as well as glucose and did not release glycerol. The brown adipose tissue of these rabbits was depleted of fat.5. The rate of blood flow through brown adipose tissue and the exchange of all three metabolites increased fourfold during noradrenaline infusion in the three groups of rabbits.6. It is concluded (i) that brown adipose tissue releases significant amounts of fatty acids and glycerol into the circulation and that this contribution is greatly increased with noradrenaline infusion and presumably cold exposure, and (ii) that brown adipose tissue depleted of fat produces heat by drawing free fatty acids as well as glucose from the circulation.     

Pulmonary sarcoidosis: A clinico-pathological study.

The light and electron microscopic changes in biopsy tissue from the lung of a 30-year-old housewife severeley incapacitated by diffuse pulmonary sarcoidosis with pulmonary hypertension are presented. The lung tissue was distorted by numerous granulomas in the interstitial tissues and within alveoli. Many pulmonary blood vessels including arteries were damaged by the granulomas. The ultrastructural features of the epithelioid cells were found to be distinctive and probably specific. The giant cells which accompanied the epithelioid cells contained two types of inclusion body: one appeared to be related to the Schaumann body but the nature and origin of the second type was not clear. Many of the granulomas were surrounded by avascular fibrous tissue which contained, in addition to mature fibroblasts, myofibroblasts and a primitive form of cell that appeared to be a fibroblast precursor. It was conjectured that the myofibroblasts, through their contractile powers, might increase the distortion of the lung architecture and thereby the patient's disability. The alveolar walls were thickened by a diffuse infiltrate of macrophages and epithelioid cells but there was no excess of collagen and elastic fibres. The evidence suggested that the epithelioid cells developed from macrophages. From the cellular nature of the diffuse infiltration of the alveolar walls and the absence of fibrosis it seemed that the disease was still at an early and active stage, a conclusion strengthened by the fact that treatment with corticosteroids led to marked and sustained clinical improvement.     

Granulomatous arteritis with massive eosinophilic leukocyte infiltration and transient peripheral eosinophilia subsequent to transarterial embolization therapy with a gelatin sponge.

A 38-year-old man presented with a cavernous hemangioma in the liver. Transarterial embolization (TAE) using a gelatin sponge was carried out 14 days prior to surgical resection of the tumor. Granulomatous arteritis with massive infiltration by eosinophilic leukocytes and histiocytes was present at the periphery of the hemangioma, and transient eosinophilia in the peripheral blood occurred six days after resection. Granulomatous arteritis was evident in medium-sized arteries and there was narrowing or occlusion of the vascular lumen. In the granulomatous cellular infiltrates in the arteries, giant cells of the foreign body type were numerous. An eosinophilic substance differing from fibrin was present in some of the vascular lumina. As this showed staining for collagen, it was considered likely to be fragments of the gelatin sponge. The patient had no symptoms of fever, chills or general fatigue. The clinical course and pathologic findings suggest a causative role of the gelatin sponge in this case of granulomatous arteritis. Vascular change, a rare complication of TAE therapy, may be induced by a hypersensitivity reaction against the intra-arterial gelatin sponge.     

Lysosomal enzyme activities in experimental granulomatous inflammation.

Foreign-body (dextran beads) and hypersensitivity (antigen-coupled agarose beads) lung granulomas were induced in BALB/c mice by the intratracheal injection of beads. Large granulomas developed, which reached peak intensity within 3 days and declined in size thereafter. Aqueous extracts of both granulomas contained high levels of lysosomal enzymes N-acetyl-beta-D-glucosaminidase (NAG) and lysozyme. Lysosomal enzyme activities in the extracts correlated with granuloma sizes. Dispersed granuloma cells were able to produce these enzymes. These results suggest that lysosomal enzymes may reflect the activity/size of granulomatous inflammation.     

T-cell lung granulomas induced by sepharose-coupled Mycobacterium tuberculosis protein antigens: immunosuppressive phenomena reversed with cyclophosphamide and indomethacin.

We induced lung granulomas in BALB/c mice by intratracheal instillation of Sepharose beads coated with a Mycobacterium tuberculosis protein extract. Granulomas composed of macrophages and lymphocytes were induced. The granulomatous reaction reached its peak 3-7 days after challenge and lasted for approximately 1 month. Immunolabelling of tissue sections and bronchial washings revealed that granulomas were predominantly composed of T lymphocytes with the cytotoxic-suppressor phenotype (CD8+). Granulomas were associated with a significant decrease in anti-mycobacterial immunity manifested by a drop in delayed-type hypersensitivity reactions and antibody titres. The immunosuppressive phenomena were abolished with cyclophosphamide or indomethacin. Control granulomas induced with methylated bovine serum albumin (BSA) were smaller and composed by similar numbers of CD4+ and CD8+ cells. BSA granulomas did not alter antibody titres but they decreased delayed-type hypersensitivity to BSA which was restored to normal with indomethacin but not with cyclophosphamide. Our findings show that mycobacterial proteins anchored to Sepharose beads are granulomatogenic and that they preferentially recruit CD8+ cells which, together with locally produced prostaglandins, down-modulate cell-mediated and humoral immunity to mycobacterial antigens.     

Surgical pathology of granulomatous interstitial pneumonia

Agranulomatous interstitial pneumonia is a form of diffuse lung disease in which granulomas are a component of the histologic findings. The differential diagnosis is quite broad, but most cases represent examples of either sarcoidosis, diffuse granulomatous infections, or hypersensitivity pneumonitis. "Hot tub lung" is a recently described form of granulomatous interstitial pneumonia that appears to have some features of diffuse infections and some features of hypersensitivity pneumonitis. The pathologist's approach to these conditions can be facilitated by giving careful attention to the anatomic distribution of the granulomas, the qualitative features of the granulomas, and the histologic changes in the lung tissue around and away from the granulomas. These features, along with the results of cultures and special stains for micro-organisms and clinical and radiologic correlation allow for a diagnosis in the vast majority of cases.     

Churg-Strauss syndrome and sudden cardiac death.

Churg-Strauss syndrome is a rare disorder characterized by necrotizing vasculitis, granulomas with eosinophilic necrosis, and tissue infiltration by eosinophils. Sudden cardiac death is rarely described in Churg-Strauss syndrome. In this article, we describe a case of Churg-Strauss syndrome with multiorgan involvement manifested as sudden cardiac death. To the best of our knowledge, this form of presentation has not been reported. A 49-year-old woman was found dead in her room. No premonitory complaints had been noted during the days preceding her death. Past medical history did not reveal any relevant illness. At autopsy, multiorganic Churg-Strauss syndrome with prominent cardiac involvement was found. Therefore, this syndrome in the active vasculitic phase may be asymptomatic and may involve predominantly the heart. This variant of the syndrome may be fulminant and present as sudden cardiac death. This form can only be elucidated by autopsy study.     

Release of histamine and formation of prostaglandins in human lung tissue and rat mast cells.

Release of histamine and prostaglandins (PGs) from human lung tissue and rat mast cells was investigated. Passively sensitized lung fragments released PGE, PGF2alpha and the 15-ketodihydro metabolites into the media with time alone. Antigen challenge liberated 20% tissue histamine and there was a twofold increase in PGs. Twice as much PGF2alpha as PGE was found. beta-Adrenergic agonists inhibited the anaphylactic release of mediators and this action was blocked by propranolol. Both PGF2alpha and PGE were consistently found in the mast cell media, demonstrating that mast cells can synthesize PGs. Anaphylaxis induced a marked liberation of histamine but not of PGs. The results indicate that the release of histamine may precede the major release of PGs and suggest that the bulk of PGs may derive from cells in the proximity of the mast cells.