Childhood Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) frequently affects children and adolescents, with most cases beginning during this time. Symptoms of OCD in youth may present as exaggerated developmental concerns and excessive ritualistic behavior beyond what is part of normal development, yet low levels of insight may prevent recognition. Affected youth commonly have comorbid neurodevelopmental diagnoses, especially males. Early detection and intervention are critical to recovery and remission, as well as family involvement in treatment. Cognitive behavioral therapy and serotonin reuptake inhibitors are first-line treatments.

The Relationship Between Adverse Childhood Experiences, Symptom Severity, Negative Thinking, Comorbidity, and Treatment Response in Youth with Obsessive-Compulsive Disorder

Although youth and adults with obsessive-compulsive disorder (OCD) endorse elevated incidence of exposure to traumatic life events during childhood, the existing literature on adverse childhood experiences (ACEs) and OCD is mixed and studies focusing on pediatric OCD are limited. The present study examines the relationship between ACEs and OCD onset, symptom severity, negative cognitive patterns, comorbidity, and cognitive-behavioral therapy (CBT) response in 142 children and adolescents with OCD. ACEs were ascertained from parent reports. Most parents reported child exposure to ACEs. Out of the parents who reported ACEs, 50% reported ACE exposure prior to OCD diagnosis and 50% reported ACE exposure after OCD diagnosis. No significant associations between ACEs and comorbidity or CBT response were found, suggesting that CBT for pediatric OCD is effective regardless of ACE exposure. Family financial problems were associated with increased obsessive-compulsive symptom severity and negative thinking. Implications for research and practice are discussed.

Lean mass predicts asthma better than fat mass among females

The obesity phenotype associated with asthma is not known. Our objective was to define the relative contribution of various distributions of fat and lean mass to asthma prevalence. Data were obtained from 2,525 participants (including 1,422 females) who underwent dual-energy X-ray absorptiometry (DEXA) at the year 20 examination in the Coronary Artery Risk Development in Young Adults (CARDIA) cohort. Total, truncal, arm and leg distributions of fat and lean mass were adjusted to the person's height. Self-reported asthma was the outcome. Asthma among females was associated with greater total fat mass, arm fat mass, total lean mass, truncal lean mass and arm lean mass. Among males, none of these mass measures were significantly associated with asthma. Among females, the association with asthma was stronger for total lean mass than for total fat mass. Further, among various regional distributions of lean and fat mass in females, truncal lean mass was the strongest predictor. Total lean mass is more strongly associated with asthma than total fat mass among females. These findings are contrary to the popular perception that excess physiological fat drives the obesity-asthma association. Rather, we hypothesise that ectopic fat within the "lean" tissues drives this association among females.

The Role of MIP-1? in Experimental Hypersensitivity Pneumonitis

S. rectivirgula (SR) causes Farmer's Lung Disease, a classic example of hypersensitivity pneumonitis (HP). We utilized a model of experimental hypersensitivity pneumonitis (EHP), antibody to MIP-1alpha and MIP-1alpha -/- mice, to test the hypothesis that MIP-1alpha is essential in the development of EHP. Treatment of C57BI/6 mice with anti-MIP-1alpha antibody did not change the extent of pulmonary histology abnormalities, BALF cell number or characteristics, or BALF concentration of IL12p40, TNF, IL1alpha and IL6, after an i.t. challenge with SR. MIP-1alpha -/- animals responded similarly to wild-type (wt) animals in the extent and nature of pulmonary histologic changes and BALF cell number and type after a single i.t. injection of SR There was a dose-response relationship between the amount of SR and BALF IL12p40, MCP-1 and IL6 in both strains, and MIP-1alpha in wild-type animals. We next transferred SR cultured spleen cells from SR sensitized mice (both wt and MIP-1alpha -/-) to naive recipients. Lung histology and BALF characteristics after SR i.t. challenge of the recipients were used to determine if adoptive transfer had occurred. Cultured cells from MIP-1alpha -/- animals were fully capable of transferring EHP to recipients. There was no difference of BALF TNF, IL6 and IL1alpha between the strains, but there was more MCP-1 and IL12p40 in the MIP-1alpha -/- mice than in the control mice. MIP-1alpha is not necessary for the recruitment of cells into the lung and BALF after i.t. administration of SR, or the development of cells able to adoptively transfer EHP.

Eosinophil traffic in the circulation following allergen challenge

BACKGROUND

Eosinophils contribute to the pathogenesis of asthma and localize to the lung after allergen exposure by uncertain mechanisms.

METHODS

We used intrabronchial instillation of allergen to model the interaction between inhaled allergen and the lung. We measured the number of peripheral blood leukocytes and the expression of VLA-4 (CD49d), Mac-1 (CD11b) and PSGL-1 (CD162) up to 4 h after instillation of allergen into a bronchus of eight atopic asthmatics. For controls, we instilled normal saline into a subset of the asthmatic subjects, and allergen into nonatopic, nonasthmatic subjects.

RESULTS

There were changes of total leukocyte number, number of polymorphonuclear leukocytes, lymphocytes, monocytes and eosinophils in all three groups (atopic asthmatics instilled with allergen, atopic asthmatics instilled with saline, nonatopic nonasthmatic subjects instilled with allergen), which were likely related to bronchoscopy. However, the decrease of eosinophils was significant only in the atopic asthmatics instilled with allergen. The remaining eosinophils in the allergen challenged asthmatics were not activated as defined by cell density or change of expression of VLA-4, Mac-1 and PSGL-1.

CONCLUSIONS

While eosinophils rapidly and specifically leave the circulation after allergen challenge of atopic asthmatics, the remaining circulating eosinophils are not activated.

Mediators of hypersensitivity pneumonitis

Inhalation of Saccharopolyspora rectivirgula (S. rectivirgula) causes farmer's lung disease, a classic example of hypersensitivity pneumonitis (HP). HP is characterized by bronchoalveolar lavage fluid (BALF) neutrophilia (within the first 48 hours after inhalation), followed by BALF lymphocytosis. We utilized a well-described murine model of HP to determine the timing of the appearance of the C-C chemokines monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1alpha (MIP-1alpha); the inflammatory cytokines tumor necrosis factor (TNF), interleukin-1alpha (IL-1alpha), and interleukin-6 (IL-6); and the Th1 -differentiating cytokine interleukin-12 (IL-12) in BALF. After a single intratracheal administration of S. rectivirgula, there was remarkable BALF neutrophilia (peak 24 to 48 hours), followed by a BALF lymphocytosis (peak 48 to 72 hours) in both C57Bl/6 and BALB/c mice that was preceded by the appearance of MIP-1alpha in BALF (peak 4 to 6 hours) and MCP-1 (peak at 48 hours). In both strains of mice there was a striking increase of BALF IL-12 (peak 48 to 72 hours). There was also an increase in BALF IL-6, IL-1alpha, and TNF that was greater in the BALB/c mice than in the C57Bl/6 mice. S. rectivirgula induced the secretion of MIP-1alpha, MCP-1, IL-6, IL-1alpha, and IL-12 from the murine macrophage cell line J774A.1; MIP-1alpha, IL-6, IL-1alpha, IL-12, and TNF from C57Bl/6 alveolar macrophages; and IL-1alpha, IL-6, and TNF-but not IL-12-from BALB/c alveolar macrophages. We conclude that chemokines and cytokines induced by intratracheal administration of S. rectivirgula precede BALF neutrophilia and lymphocytosis and may cause differentiation of Th1 cells; we also conclude that pulmonary macrophages represent a potential source of these substances.

Experimental hypersensitivity pneumonitis: influence of Th2 bias

Cultured murine CD4+ cells from Saccharopolyspora rectivirgula sensitized C3H/HeJ (Th1 bias) donors can adoptively transfer murine experimental hypersensitivity pneumonitis (EHP). We sensitized BALB/c mice (Th2 bias) with S. rectivirgula, obtained spleen and lung associated lymph node (LALN) cells, cultured the cells with specific antigen, and attempted adoptive transfer of EHP. We also treated both C3H/HeJ and BALB/c donor mice with IL4 and anti-IFNgamma before exposure to S. rectivirgula and then cultured cells from both spleen and LALN before attempted transfer of EHP. We found that cultured spleen and lung associated lymph node cells can adoptively transfer EHP in both C3H/HeJ and BALB/c mice as demonstrated by infiltration of the recipient lungs with CD4+ lymphocytes. Treatment of both mouse strains with IL4 and anti-IFNgamma did not change the ability of cultured cells to adoptively transfer EHP. We conclude that EHP induced by S. rectivirgula can occur in animals with either a Th1 or a Th2 bias and is not altered by treatment with IL4 and anti-IFNgamma. This suggests that attributes of the antigen and not genetic background or cytokine environment at the site of initial sensitization determines the results of exposure to S. rectivirgula.

Th1 cells that adoptively transfer experimental hypersensitivity pneumonitis are activated memory cells

Cultured murine CD4+ T cell lines from Saccharopolyspora rectivirgula-sensitized donors with cytokine secretion characteristics of Th1 cells can adoptively transfer murine experimental hypersensitivity pneumonitis (EHP), whereas Th2 CD4+ cell lines cannot (Cell Immunol 177:169-175, 1997). To assess the differences between these cell lines that may be related to the ability to transfer EHP, we determined cell surface markers that distinguish naive from activated/memory cells that indicate activation and that mediate endothelial adhesion. Both Th1 and Th2 T cell lines are CD4+, CD11a+, ICAM-1+, and L-selectin negative. Th1 cells are CD49d (alpha 4) and LPAM (alpha 4 beta 7) positive, with 32% and 42% of the apparent membrane site density quantitated as the mean molecules of equivalent soluble fluorochromes (MESF) values of unstimulated spleen cells, respectively. Th2 cells are weakly alpha 4 and alpha 4 beta 7 positive, with 15% and 11% of the MESF of unstimulated spleen cells. Th1 cell lines are CD45Rb negative and CD44+, whereas Th2 cell lines are CD45Rb intermediate and CD44-/low. Th1 cells are CD25 (IL-2 receptor) low and Th2 cells CD25 high. We conclude that Th1 cells capable of transfer are activated/memory T cells, and Th2 cells incapable of transfer lack some characteristics of memory/activated T cells (i.e., increase of CD44 and decrease of CD45Rb). Both Th1 and Th2 cell lines express alpha 4 beta 7 and alpha 4 (Th1 > Th2), suggesting that alpha(4) integrin may be important in conferring ability to cells to adoptively transfer EHP.

Experimental hypersensitivity pneumonitis: location of transferring cells

Cultured cells from Micropolyspora faeni-sensitized donors can adoptively transfer murine experimental hypersensitivity pneumonitis (EHP). We sought to determine the location of transferred cells in recipient animals, the influence of the origin of the cultured cells, and the effect of specific intratracheal challenge. We labeled cultured sensitized spleen or lung-associated lymph node (LALN) cells with CFDA-SE, a cytoplasmic stain, before transfer to naive recipients, which were sacrificed 1 h, 1 day, or 4 days thereafter. We also transferred labeled cultured spleen cells to recipients that were challenged with intratracheal M. faeni and sacrificed 4 days later (MF). Controls were recipients of M. faeni-sensitized and cultured cells challenged with intratracheal normal saline (NS) and recipients of ovalbumin (OVA)-sensitized cells cultured with M. faeni and challenged with intratracheal M. faeni (OVA). The number and proportion of cells that were stained were determined in dispersed spleen, peripheral and lung-associated lymph nodes, and lung parenchyma. The extent of the pulmonary inflammatory response was measured by determining the proportion of microscopic fields that were abnormal and the total number of dispersed pulmonary cells. CFDA-SE stained cells uniformly, and stained cells could be detected in recipients for up to 7 days after transfer. CFDA-SE treatment (0.5 microM) did not affect the ability of cells to transfer EHP adoptively. Transferred cells could be detected easily in lung, lung-associated and peripheral lymph nodes, blood, and spleen. Transferred cells localized to the lung at 1 h but then rapidly decreased with no difference between labeled cells from spleen and LALN. After intratracheal M. faeni challenge, there was no difference in the proportion of labeled cells in the lung among any of the groups (MF, NS, or OVA). There was an increase in the number of lung cells in the MF group compared with the control (NS and OVA) groups. We conclude that cells capable of transfer are transiently (1 h) trapped in the lung but are much decreased in the lung by four days after transfer. After intratracheal antigen challenge of recipients, there is a substantial increase in the number of pulmonary cells in animals exhibiting adoptive EHP but not in the control groups. Transferred cells responsible for EHP are increased in the lungs of animals with adoptive EHP.

Effect of glucan on murine lungs

Glucan, a folded high-molecular-weight polysaccharide, has multiple effects in animals when administered intravenously or intraperitoneally, but not when administered by inhalation. The hypotheses tested were whether intratracheal administration of glucan can cause lung damage and whether some of the resulting lung injury is immunologically mediated. There was a dose-response relationship between the amount of intratracheally injected glucan and the extent of pulmonary histologic abnormalities, which consisted of peribronchiolar and intraalveolar infiltration with chronic inflammatory cells. An attempt to adoptively transfer increased susceptibility to glucan induced lung injury was made. Cells cultured with glucan were transferred into naive recipients before intratracheal glucan exposure. The extent of pulmonary inflammation that occurred as a result of intratracheal injection of glucan was not affected by transfer of cultured cells from glucan-treated animals. However, high concentrations of glucan in culture did produce cells with the appearance of lymphoblasts. These data indicate that glucan induces lung injury, but that there is no evidence of cell mediation of pulmonary injury induced by intratracheal exposure to glucan.

Immunoglobulin response to intrapulmonary immunization of asthmatics

Atopic asthmatics, compared to non-atopic individuals, exhibit an increased amount of serum antigen-specific IgE and IgG4 antibody directed toward many aeroallergens. We tested the hypothesis that this difference between atopics and non-atopics extends to the response to intrapulmonary deposition of a neoantigen, keyhole limpets haemocyanin (KLH). We immunized nine atopic asthmatics and nine non-atopic controls with 500 micrograms KLH instilled into a subsegment of the lingula and examined serum anti-KLH, IgG1, IgG2, IgG3, IgG4, IgA1, IgA2, and IgM and specific antibody production by peripheral blood mononuclear cells for 25 days. We also determined specific antibody in bronchoalveolar lavage fluid (BALF) in both the immunized and a non-immunized lobe 11 days after immunization. We found specific serum antibody in all immunized subjects with no difference between atopics and normals in the amount or kinetics of anti-KLH IgG1, IgG2, IgG3, IgA1, IgA2 and IgM. However, the atopics exhibited more anti-KLH IgG4 than the normal controls. Specific anti-KLH antibody-producing cells were detected in peripheral blood in most subjects at day 8 to 12 after immunization with no difference between atopics and normals. Specific IgA1, IgA2, IgG1 and IgM antibodies were detected in BALF from the immunized lobes but not from the non-immunized lobes of both groups of subjects with no difference between atopics and normals. We conclude that atopic asthmatics respond to intrapulmonary KLH with more serum anti-KLH IgG4 than normal controls, consistent with a bias toward a Th2 response to intrapulmonary exposure to antigen.

Th1 CD4+ cells adoptively transfer experimental hypersensitivity pneumonitis

Cultured cells from Micropolyspora faeni-sensitized donors can adoptively transfer murine experimental hypersensitivity pneumonitis (EHP). To determine whether the CD4+ cells responsible for transfer have characteristics of Th1 or Th2 cells, we established cell lines from lung-associated lymph nodes of M. faeni-sensitized C3H/HeJ mice by culturing with antigen and either IFN-gamma, IL2, and anti-IL4, or IL4. Cell lines were stimulated regularly with antigen, fresh antigen-presenting cells, and the cytokine/anti-cytokine antibody cocktail. At various times after initiation of culture, cells were injected intravenously into recipients, which were then challenged intratracheally with M. faeni and sacrificed and the extent of pulmonary inflammatory response was determined. IFN-gamma, IL4, and IL10 levels were determined in supernatants of cell cultures stimulated with M. faeni to characterize the cell lines as Th1 (IFN-gamma, but low IL4 and IL10 secretion) or Th2 (IL4 and IL10, but low IFN-gamma secretion). Cell lines were differentiated into either Th1 (IFN-gamma = 310 +/- 45 U/ml, IL4 = 0.10 +/- 0.1 U/ml, IL10 = 1750 +/- 75 pg/ ml, >99% CD4+) cell lines by Day 16 of culture or Th2 cell lines (IFN-gamma = 1.8 +/- 1.0 U/ml, IL4 = 830 +/- 388 U/ml, IL10 = 51,700 +/- 10,900 pg/ml, >96% CD4+) by Day 30. Th1 cell lines were able to adoptively transfer EHP whereas Th2 cell lines were unable to adoptively transfer EHP. The ability to transfer EHP was directly related to the amount of IFN-gamma and inversely to the amount of IL4 secreted by antigen-stimulated cells. We conclude that it is possible to produce CD4+ cell lines with either Th1 or Th2 characteristics from lung-associated lymph nodes of mice exposed to M. faeni and that only Th1 CD4+ cell lines can adoptively transfer EHP.

Experimental hypersensitivity pneumonitis: cellular requirements

We previously demonstrated that Thy1.2+, CD4+, Ia-T cells are responsible for transfer of murine adoptive experimental hypersensitivity pneumonitis (adoptive EHP). To characterize the culture conditions necessary for development of these cells, we depleted cell cultures of Thy1.2+, CD4+, CD8+, or Ia+ cells using MoAbs and complement or magnetic beads, prior to culture of sensitized C3H/HeJ murine spleen cells (SC) with Micropolyspora faeni. After culture, cells were transferred to recipients which were later challenged intratracheally with M. faeni. The extent of pulmonary inflammatory changes in these animals was determined 4 days after intratracheal (i.t.) challenge with M. faeni. Cultured M. faeni-sensitized SC which had been treated before culture with media, complement only, anti-CD8 plus complement or magnetic beads alone could transfer EHP to naive animals. SC treated with anti-Thy1.2 or anti-CD4 plus complement could not transfer EHP. Treatment of SC with anti-Iak plus magnetic beads diminished the ability of cultured cells to transfer EHP. We conclude that the ability to produce cells able to adoptively transfer EPH is dependent on the presence of Thy1.2+, CD4+, and Ia+ cells, but not CD8+ cells, at the onset of culture.

The law of workplace violence

In addressing law related to workplace violence and employers' obligations, the authors analyze the quagmire of the often conflicting rights of the victim, the perpetrator, and third parties. The close attention that courts are now giving to workplace violence and the scores of legislative efforts to deal with it are assessed.

Experimental hypersensitivity pneumonitis: in vitro effects of interleukin-2 and interferon-gamma

Cultured CD4+ cells are responsible for transfer of adoptive murine experimental hypersensitivity pneumonitis (EHP) (ARRD 1992; 146:1582-8). To characterize interactions that occur in vitro that result in cells able to transfer EHP, we added either antibody to IFN-gamma, antibody to IL-2, or 30 or 300 micrograms/ml IFN-gamma at the onset of 72-hour culture of C3H/HeJ spleen cells from either M. faeni or ovalbumin (control) sensitized donors with 30 micrograms/ml Micropolyspora faeni. We determined the phenotype of cells after culture and the amount of IL-2 or IFN-gamma in the culture supernatants, transferred cells to naive recipients, challenged the recipients intratracheally with M. faeni, and determined the extent of pulmonary inflammatory changes 4 days thereafter. Substantial amounts of IL-2 and IFN-gamma were detected in supernatants of cultures from M. faeni-sensitized animals, and lesser amounts were detected in culture supernatants from ovalbumin-sensitized donors. Treatment of cultures of M. faeni-sensitized cells with antibody to IL-2 or IFN-gamma blocked or reduced measurable IL-2 or IFN-gamma for the duration of culture. Treatment with IFN-gamma blocked increased levels of IL-2 at 48 and 72 hours of culture. Cultured M. faeni-sensitized cells adoptively transfer EHP. Cells from cultures depleted of either IL-2 or IFN-gamma or supplemented with IFN-gamma could transfer EHP equally well. We conclude that in vitro maturation of cells capable of adoptive EHP is not dependent on soluble IL-2 or IFN-gamma and is not altered by exogenous IFN-gamma.

Experimental hypersensitivity pneumonitis: effect of Thy1.2+ and CD8+ cell depletion

We previously demonstrated that recipient CD4+ cells are necessary for expression of adoptive murine experimental hypersensitivity pneumonitis (EHP). In contrast, the acute inflammatory response to intratracheal (i.t.) administration of Micropolyspora faeni (direct EHP) is not CD4+ cell dependent (Am. J. Respir. Crit. Care Med. 1994;149:1286-1294). To further characterize the cells responsible for development of pulmonary inflammation in recipient animals, we depleted recipients of either Thy1.2+ or CD8+ cells before transfer of M. faeni-sensitized cultured C3H/HeJ spleen cells and i.t. challenge with M. faeni. We used the same depletion technique to determine the contribution of these cells to the pulmonary response to i.t. M. faeni in animals that did not receive cultured cells (direct EHP). The nature and extent of pulmonary inflammatory changes in these animals were assayed either 4 d after i.t. challenge with M. faeni in adoptive EHP or 2 d after i.t. challenge with M. faeni in direct EHP. We also tested the hypothesis that our previously demonstrated ablation of adoptive EHP caused by administration of anti-CD4 antibody was due to depletion of recipient CD4+ cells by allowing recovery of recipient CD4+ cells of anti-CD4-treated animals before i.t. challenge. In addition, we allowed Thy1.2+ cell recovery of anti-Thy1.2-treated animals before i.t. challenge. Cultured M. faeni-sensitized spleen cells could adoptively transfer EHP to animals treated with an irrelevant antibody or PBS. Depletion of Thy1.2+ but not CD8+ cells ablated the ability of recipient animals to express adoptive EHP. Direct EHP was not affected by depletion of Thy1.2+ or CD8+ cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental hypersensitivity pneumonitis. Effect of CD4 cell depletion

We previously demonstrated that Thy1.2+, CD4+, Ia-T cells are responsible for transfer of adoptive murine experimental hypersensitivity pneumonitis (adoptive EHP). To characterize the cells responsible for development of pulmonary inflammation in the recipient animals, we depleted recipients of CD4+ cells using monoclonal antibody GK1.5 before administration of Micropolyspora faeni-sensitized cultured C3H/HeJ spleen cells (SC) and intratracheal (i.t.) challenge with M. faeni. We also used the same depletion technique to determine the contribution of these cells to the pulmonary response to i.t. M. faeni in animals that did not receive cultured cells (direct EHP). The nature and extent of pulmonary inflammatory changes in these animals were assayed either 4 days after i.t. challenge with M. faeni in adoptive EHP or 2 days after i.t. challenge with M. faeni in direct EHP. Cultured M. faeni-sensitized SC could transfer EHP to naive animals or those treated with an irrelevant antibody. Depletion of CD4+ cells ablated the ability of recipient animals to express adoptive EHP. Two days after i.t. M. faeni (direct EHP), there was extensive neutrophilic infiltration of the lung that was not affected by depletion of CD4+ cells. We conclude that the ability to express adoptive EHP is dependent on the presence of CD4+ cells. In contrast, the acute inflammatory response to M. faeni is not CD4+ cell dependent.

CD3+ and CD4+ cells adoptively transfer experimental hypersensitivity pneumonitis

To characterize the cells responsible for transfer of adoptive murine experimental hypersensitivity pneumonitis (EHP), we depleted Micropolyspora faeni (M. faeni)-sensitized C3H/HeJ spleen cell (SC) cultures of CD3+, CD4+, or CD8+ cells before administration to recipients. We determined the length of time sensitization persists, the ability of cultured lung-associated lymph node (LALN) cells to transfer EHP, and the ability of cultured SC from animals subjected to two, four, or eight weekly intratracheal challenges of M. faeni to transfer EHP. The extent of pulmonary inflammatory response after challenge with intratracheal M. faeni was used to determine adoptive transfer. Depletion reduced the proportion of CD3+ cells from 21 to 1%, CD4+ cells from 15 to 3%, and CD8+ cells from 7 to 1% in the cultured SC population. The proportion of B cells exhibited reciprocal changes. Cultured SC could transfer EHP. Depletion of CD3+ and CD4+, but not CD8+ cells, ablated or diminished the capacity to transfer EHP. Sensitized cells persisted in recipients for at least 8 wk. Cultured LALN cells could transfer EHP. Recipients of cultured SC from 4- and 8-wk donors exhibited less extensive pulmonary abnormalities than recipients of cultured SC from 2-wk donors. The proportion of CD3+, CD4+, CD8+, B cells, and macrophages was the same in cultured cells from 2-, 4-, and 8-wk donors. We conclude that the active cells in SC cultures are CD3+, CD4+, and CD8- T cells, and there are differences in the ability of cultured cells to adoptively transfer EHP that are dependent on the nature of the donor but not on the phenotype of the cell population.

Risk factors for the degradation of lung elastic fibers in the ventilated neonate. Implications for impaired lung development in bronchopulmonary dysplasia

In order to evaluate the risk for proteolytic destruction of lung parenchymal elastic fibers in ventilated premature infants, the concentrations of elastase were determined in tracheal aspirates of 65 infants from whom we obtained a total of 327 sequential samples. Elastase was detected at least once in 39 of the 65 infants studied. Eleven of these infants were ventilated with greater than 60% oxygen for greater than 5 days. In 19 infants, the presence of elastase was associated with positive bacterial and/or viral cultures and/or elevated ratios (greater than 0.22) of immature neutrophils to total neutrophils. Elastase was not detected in the lung secretions of 26 infants ventilated with greater than 60% oxygen for less than 3 days, suggesting minimal risk for elastic fiber destruction in the intubated infant who neither has pneumonia nor requires prolonged hyperoxic ventilation. The risk for elastic fiber destruction was further evaluated by analyzing sequential urine and tracheal aspirate samples for the presence of an elastolytic degradation product of elastin (desmosine). The biochemical data indicated a potential risk for proteolytic destruction of elastic fibers in association with infection and/or prolonged hyperoxic exposure. In addition, autopsy specimens obtained from three of the infants revealed structurally abnormal lung parenchymal elastic fibers. Because elastic fibers are believed to provide the structural support for alveolar septal development, proteolytic degradation of these fibers may be a significant factor in the impaired lung development that occurs in infants with bronchopulmonary dysplasia.

Experimental murine hypersensitivity pneumonitis

To establish a model of experimental hypersensitivity pneumonitis (EHP) in mice and to examine the influence of genetic background on the pulmonary inflammatory response to Micropolyspora faeni, we determined the responses of C57BL/6, SJL/J, and C3H/HeJ mice to intratracheal (i.t.) injections of M. faeni. Recipient animals received lymph node cells (LNC), peritoneal exudate cells (PEC), and spleen cells (SC) from sensitized mice cultured in vitro with M. faeni. Controls included serum containing anti-M. faeni antibody; uncultured SC from M. faeni-sensitized donors, and M. faeni-cultured SC from ovalbumin (OA)-sensitized donors. Recipients were challenged i.t. with M. faeni or normal saline 48 hr after the cell or serum transfer. We developed a model of EHP in mice. Increasing amounts of i.t. M. faeni were associated with increasing extent of pulmonary inflammation with no difference between the mouse strains. There was substantial increase of the extent of pulmonary abnormalities in the animals receiving cultured SC. The number of transferred cells and the M. faeni concentration correlated with the extent of pulmonary histologic abnormalities. Cultured PEC and LNC could transfer EHP in C3H/HeJ mice only. Serum containing anti-M. faeni antibody, cultured SC from OA-sensitized donors, and noncultured SC from sensitized donors could not transfer EHP. We conclude that it is possible to adoptively transfer EHP.

Mast cell hyperplasia in experimental hypersensitivity pneumonitis

We investigated the presence of mast cells in a model of experimental hypersensitivity pneumonitis (EPH). Guinea pigs exposed to 8 weekly intratracheal challenges with Micropolyspora faeni exhibited significant increases in the number of mast cells within the lung as compared to controls and animals challenged only 2 or 4 times. The number of cells in M. faeni-challenged animals were increased around bronchi, bronchioles, blood vessels and in alveolar septa. There appeared to be contraction of peribronchial, peribronchiolar and vascular smooth muscle. Ultrastructural examination of lung tissue revealed the presence of degranulating mast cells. Bronchoalveolar lavage histamine levels were increased after 8 but not after 2 or 4 weekly challenges. Serum anti-M. faeni antibody was present in all M. faeni-exposed animals but not in control animals. We conclude that mast cells and histamine levels in bronchoalveolar lavage fluid are increased in a model of EHP caused by repetitive, intratracheal injection of M. faeni particulate antigen.

Antigen-induced T-cell changes: modulation by pharmacologic agents

To determine the effect of pharmacologic modulation of alterations of peripheral blood T-cell subsets caused by antigen-induced bronchoconstriction, we administered albuterol immediately after antigen-induced bronchoconstriction in a double-blind to protocol to 12 atopic asthmatic subjects. We also administered cromolyn sodium before antigen to 7 of the same subjects. Peripheral blood T-cell subset composition (CD4, CD8, Ia) of a highly purified T-cell preparation was determined before, 24, 48, 72, and 168 h after bronchoconstriction. We found that placebo inhalation immediately after antigen-induced bronchoconstriction did not affect subsequent peripheral blood T-cell subset changes (decrease in CD4+ and increase in Ia+ T lymphocytes). In contrast, inhaled albuterol abolished these T-cell subset changes. Although cromolyn sodium significantly decreased the severity of antigen-induced bronchoconstriction, it did not affect T-cell subset composition changes at the dosage used. We conclude that albuterol can ablate T-cell subset changes associated with antigen-induced bronchoconstriction. Cromolyn sodium ameliorates bronchoconstriction, but has no affect on T-cell subset composition changes. This implies that T-cell changes and bronchoconstriction caused by antigen inhalation are mediated through different pathways.

Experimental hypersensitivity pneumonitis: influence of donor sensitization

Experimental hypersensitivity pneumonitis (EHP) can be transferred to strain 2 guinea pigs by lymphoblasts from lymph node cells from sensitized guinea pigs cultured in vitro with antigen. We sought to examine the relationship between characteristics of the donor animal and development of competence to transfer EHP. We also compared cell populations that were capable and incapable of transfer using flow cytometry and fluorescein conjugated anti-Ig to determine cell size and surface IgG + (SIg +: surface immunoglobulin-positive) cells. Lymph node cells from donor animals were cultured with a soluble extract of Micropolyspora faeni (10 micrograms/ml) for 72 hours; blasts were then isolated and transferred intravenously to syngeneic recipients. Control recipients received an equal volume of medium. Four groups of donors were used: animals systemically sensitized with Freund's adjuvant and M. faeni and challenged with two, four, or eight weekly intratracheal injections of M. faeni (2-, 4-, and 8-week group); and animals sensitized with Freund's adjuvant and normal saline and challenged with two weekly intratracheal injections of normal saline (NS group). Recipients were challenged intratracheally with M. faeni 48 hours after the cell transfer and killed 4 days thereafter. Randomly selected microscopic fields of the lung (250/animal) were judged to be normal or abnormal without knowledge of treatment. All animals were maintained in high efficiency particulate accumulator-filtered air. There was a low level of pulmonary response to an intratracheal challenge of M. faeni in animals that received media.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental hypersensitivity pneumonitis in guinea pigs. Kinetics and dose response

Experimental hypersensitivity pneumonitis (HP) can be transferred by cells cultured in vitro with antigen, but not by noncultured cells. We determined the relationship between antigen concentration, time of culture, and development of competence to transfer HP and if separation of lymphoblasts from a noncultured cell population would allow transfer. We cultured lymph node cells from sensitized Strain II guinea pigs with a soluble extract of Micropolyspora faeni (10 micrograms/ml) for 48, 72, and 96 h, and isolated and transferred lymphoblasts intravenously to syngeneic recipients. Other animals received lymphoblasts from 72-h cultures exposed to 0, 0.1, 1, 10, or 30 micrograms/ml M. faeni. We also separated and transferred lymphoblasts from noncultured lymph node cell populations. Control animals received equal volumes of media. The animals were challenged intratracheally with M. faeni 48 h after the cell transfer, and they were killed 4 days after intratracheal challenge. Randomly selected microscopic fields of the lung (250/animal) were judged to be normal or abnormal without knowledge of treatment. All guinea pigs were maintained in HEPA-filtered air. There was a low level of pulmonary response to an intratracheal challenge of M. faeni in animals that received media and a substantial increase (p less than 0.01) in the extent of pulmonary abnormalities in the animals receiving lymphoblasts cultured for 72 and 96 but not for 48 h. Recipients of lymphoblasts cultured for 72 h with 1, 10, and 30 but not zero and 0.1 micrograms/ml M. faeni exhibited increased extent of pulmonary abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Blast cells transfer experimental hypersensitivity pneumonitis in guinea pigs

We previously demonstrated that experimental hypersensitivity pneumonitis (HP) can be transferred by lymph node cells (LNC) cultured in vitro with antigen. The purpose of this study was to identify the cells responsible for transfer and to determine if pulmonary cells can transfer HP. We cultured LNC from sensitized Strain 2 guinea pigs with a soluble extract of Micropolyspora faeni for 72 h, separated lymphoblasts from small lymphocytes, and transferred both subpopulations intravenously to syngeneic recipients. We also transferred irradiated lymphoblasts (1,500 rads), macrophage-depleted, lymphoblast-enriched populations, and pulmonary cells either without culture or after culture with M. faeni. Control animals received an equal volume of medium. All recipient animals were challenged intratracheally (i.t.) with M. faeni 48 h after the cell transfer, and they were killed 4 days after i.t. challenge. Randomly selected microscopic fields of the lung (250/animal) were judged to be normal or abnormal without knowledge of treatment. This measurement was reproducible (r = 0.95 for duplicate measurements, n = 55). All guinea pigs were maintained in HEPA-filtered air. There was a low level of pulmonary response to an i.t. challenge of M. faeni in animals that received medium. Animals that received pulmonary cells, either cultured or noncultured, did not differ from those in the control group. There was a substantial increase (p less than 0.01) in the extent of pulmonary abnormalities in the recipients of the lymphoblast population, with significant correlation (r = 0.87, p less than 0.01) between the number of lymphoblasts transferred and the extent of pulmonary abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Prolonged exposure to M. faeni in strain II guinea-pigs: pulmonary interstitial inflammation

Models of hypersensitivity pneumonitis (HP) should exhibit progression of pulmonary histological abnormalities during continuing challenges. Strain II guinea-pigs were sensitized with Micropolyspora faeni and received 2, 4, or 8 weekly intratracheal (i.t.) particulate M. faeni challenges. Control animals received normal saline (NS). Four days after the last exposure, randomly selected microscopic fields of lung (200/animal) were judged to be normal or abnormal. If abnormal, the location and nature of the abnormalities were determined. Compared with NS treated guinea-pigs, those exposed to 2, 4 and 8 weekly M. faeni challenges exhibited more extensive (P less than 0.001) pulmonary histological abnormalities which involved both the intraalveolar and interstitial compartments. More extensive abnormalities in the 8 week group compared with the 4 week group were caused by increased extent of interstitial mononuclear cell infiltration. The extent of pulmonary interstitial histological abnormalities transiently (four challenges) decreases, but then increases, so that progressive pulmonary inflammation occurs during continuing challenges.

Experimental hypersensitivity pneumonitis: transfer with cultured cells

The importance of antibody and sensitized cells in hypersensitivity pneumonitis (HP) is unknown. In an attempt to create a model suitable for investigation of the mechanisms of HP, we transferred cells and serum from sensitized (Micropolyspora faeni in Freund's adjuvant) strain 2 guinea pigs to naive animals. Cells (peritoneal exudate, lymph node, or spleen) were cultured for 72 hours with either concanavalin A (Con A, 1 microgram/ml) or a soluble extract of M. faeni (10 micrograms/ml). We then injected the cells intravenously (IV) into naive guinea pigs, skin tested with purified protein derivative (PPD), challenged the animals intratracheally (IT) with M. faeni 48 hours after the cell transfer, and killed them 4 days (IT) with M. faeni 48 hours after the cell transfer, and killed them 4 days after IT challenge. We also transferred noncultured cells and antibody-containing serum from sensitized animals. Randomly selected microscopic fields of the lung (150 per animal) were judged to be normal or abnormal. All guinea pigs were maintained in high-efficiency particulate accumulator-filtered air. Compared with control animals that received media IV, there was a substantial increase (P less than 0.01) in the extent of pulmonary abnormalities in the animals receiving lymph node cells or spleen cells cultured with M. faeni, and peritoneal exudate cells cultured with Con A. Findings in recipients of peritoneal exudate cells cultured with M. faeni, or lymph node cells or spleen cells cultured with Con A did not differ from those in the control group. In contrast to cultured cells, noncultured cells and antibody-containing serum did not transfer susceptibility. PPD skin reactivity was present only in recipients of noncultured cells and not in recipients of serum or cultured cells. We conclude that experimental HP can be transferred with cultured cells from sensitized animals and that HP appears to be a cell-mediated process.

Atopic asthma: T lymphocyte subpopulations

Atopy is associated with diminished cell-mediated immunity and increased amounts of IgE, both of which may be caused by imbalances of T lymphocyte subsets. We compared the composition of highly purified peripheral-blood T cells of fifteen atopic asthmatics with ten non-atopic control subjects. Each subject was examined on five separate occasions. Indirect immunofluorescence using monoclonal antibodies was used to define T cell subsets. We examined the proportion of T cells with T3 (most T cells), T4 (helper/inducer), T8 (suppressor/cytotoxic), M1 (natural killer), and Ia (activated T cells) surface antigens. Blood was obtained at the same time of day to eliminate the effects of circadian rhythm. Subjects were taking no medications. We found no difference between the groups of the percentage of T cells with T4, T8, M1, and Ia antigens, nor the ratio of T4+ (helper) to T8+ (suppressor) cells. T3 percent was slightly (94.3 vs 92.5%) higher in the atopic group. We conclude that atopic asthma is not associated with imbalances of peripheral-blood T cell subsets.

Atopic asthma: T-cell response to corticosteroids

Atopic asthma is associated with diminished cell-mediated immunity and elevated levels of IgE, both of which may be caused by imbalances of T-lymphocyte subsets. We analyzed the response of peripheral blood T-cell subsets to two commonly used corticosteroid preparations as a probe of T-cell subset regulation. We administered prednisone (P) 60 mg or 20 mg, beclomethasone dipropionate (BDP) aerosol, 336 micrograms, placebo, or BDP vehicle in a double-blind protocol to 15 atopic asthmatic patients and ten nonatopic subjects. No difference was found between the groups of the baseline number of T-cells with T4, T8, M1, and Ia antigens, nor the ratio of T4+ (helper) to T8+ (suppressor) cells. Five hours after administration of BDP aerosol, BDP vehicle, and oral placebo, there was no change of these values in either the atopic or in the nonatopic group. In contrast, P, 20 and 60 mg, caused a fall of T4/T8 ratio in the atopic, but not in the nonatopic population. Atopic asthma is not associated with baseline imbalances of peripheral blood T-cell subsets, but is associated with an abnormal response to systemic, but not inhaled corticosteroid.

Alveolar macrophage plasminogen activator

Plasminogen activator is a neutral serine protease secreted by many different cells, including activated peritoneal macrophages, which can mediate both inflammation and fibrinolysis and perhaps cytolysis of tumor cells. Secretion of plasminogen activator by rabbit alveolar macrophages derived from normal animals and rabbits pretreated with bacillus Calmette-Guérin (BCG) to activate these macrophages was examined. Plasminogen activator was secreted into media of cultured alveolar macrophages, but was not present within the cells. Secretion, which was dependent upon the presence of viable cells, could be blocked by protein synthesis inhibitors and enhanced by concanavalin A and phorbol myristate acetate. The inhibition profile of rabbit alveolar macrophage plasminogen activator is consistent with that of a serine protease. Plasminogen activator is present in two forms with molecular weights of 28,000 and 45,000. Alveolar macrophage plasminogen activator was secreted in cultures from most rabbits (17 of 23) pretreated with BCG, but rarely in those from normal animals (2 of 14). Lavage fluids from many rabbits contained viable Bordetella bronchiseptica, but the presence of this organism showed no correlation with secretion of plasminogen activator. Rabbit alveolar macrophages secrete a plasminogen activator similar to that secreted by mouse peritoneal macrophages as described previously. Secretion is enhanced by activation of alveolar macrophage populations.

Elastolysis of insoluble elastin

We developed an assay for measurement of elastolytic activity using insoluble 3H-labelled particulate elastin adherent to plastic that is capable of detecting 150 picograms of pancreatic elastase. This equals or exceeds the sensitivity of the most sensitive previously reported systems, without requiring sodium dodecyl sulfate treatment of the elastin. Elastin digestion is dependent upon substrate and elastase concentration, but is not linearly related to time. This is partially attributable to elastase denaturation or autolysis under the assay conditions. The assay could easily detect elastase secreted by either peritoneal or alveolar macrophages. Compared to previously described assays using substrates that closely resemble the physiologic substrate, this represents a considerable increase of sensitivity of detection of elastolytic activity of enzymes.

Hypersensitivity pneumonitis in strain II guinea pigs. II. Immunologic features

A model of hypersensitivity pneumonitis (HP) in syngeneic animals would allow experiments designed to determine immunopathogenesis of HP. Strain II guinea pigs were treated with Micropolyspora faeni and challenged with intratracheal M. faeni. Skin test, serum antibody, hilar lymph node lymphocyte proliferation and bronchoalveolar macrophage migration inhibition (MMI) response to M. faeni antigen were determined. Sensitized animals had positive delayed skin tests, serum antibody and bronchoalveolar cell MMI, but not M. faeni-induced hilar node lymphocyte proliferation. We conclude that this model is suitable for examination of the importance of various mechanisms which might be important in HP.

Hypersensitivity pneumonitis in strain II guinea pigs. I. Histologic features

A model of hypersensitivity pneumonitis (HP) in syngeneic animals would allow experiments designed to determine immunopathogenesis of HP. Strain II guinea pigs were treated with Micropolyspora faeni and challenged with intratrachael M. faeni. Lung histology 4 days thereafter was quantitatively evaluated. Intratrachael administration of M. faeni caused interstitial and intraalveolar collections of mononuclear and polymorphonuclear cells. Sensitized (pretreated with M. faeni) animals' lungs had more extensive pathology than unsensitized animals. 3 weeks after challenge with M. faeni, pulmonary histopathology regressed to granulomatous interstitial infiltration, similar to that found in chronic HP in humans. We conclude that the pulmonary histopathologic response of sensitized strain II guinea pigs to intratrachael M. faeni resembles human HP.

Diminished suppressor cell function in patients with asbestosis

Epidemiological and immunological studies of asbestos workers documented abnormalities in humoral and cell-mediated immunity which could result from defective immunoregulation. This study tests this hypothesis with comparison of lymphocyte function in age-, sex- and smoking-matched subjects with asbestosis. In vivo measure of delayed hypersensitivity (i.e. skin test response) was significantly depressed to two recall antigens, SKSD and Candida, in asbestosis patients. Skin reaction to dinitrochlorobenzene (DNCB) was not depressed, although lymphocytes of patients giving positive skin test reactions demonstrated a significantly lower (P less than 0.001) proliferative response to dinitrobenzene sulphonic acid (DNBSO3) in vitro. T cell counts (E-rosettes) were normal in patients with asbestosis, although a subset of T cells, those forming sheep erythrocyte rosettes after prolonged incubation (Elate), were significantly depressed (P less than 0.003). This population has been equated with 'suppressor' cells (Grossi et al., 1978). Numbers of B cells were increased nearly two-fold over controls. Mitogen response of lymphocytes was normal except at suboptimal doses of mitogens where the response is known to be influenced by suppressor cell activity, which was significantly elevated. Suppressor cell function, as determined by stimulation of peripheral blood lymphocytes preincubated with concanavalin A, was also significantly decreased in asbestosis patients (P less than 0.01).

Cell-mediated immunity in silicosis

Selected parameters of cell-mediated immunity were determined in a group of 16 patients with silicosis. The results were compared with those of a control group of 13 subjects without silica exposure. There were no group differences in the mean number of delayed hypersensitivity skin tests to a battery of recall antigens (purified protein derivative, candida, streptokinase-streptodornase, and trichophyton) or in the mean number of peripheral blood lymphocytes. Lymphocyte responsiveness to phytohemagglutinin, pokeweed mitogen, and the antigens listed, and the percentage of lymphocytes that formed sheep red blood cell rosettes (t cells) and complement rosettes (B cells) were also similar in both groups; however, the silica-exposed group demonstrated depressed lymphocyte stimulation in response to low concentrations of concanavalin A.