In vitro and in vivo expression of interstitial collagenase/MMP-1 by human mast cells

Degradation of the extracellular matrix occurs under physiological and pathological conditions, thought to be principally mediated by a family of neutral proteolytic enzymes termed the matrix metalloproteinases (MMPs). The present study was initiated to determine whether mast cells have the ability to produce these proteases in diseased and normal human tissue. Immunohistochemistry and in situ hybridization was performed to localize interstitial collagenase protein and mRNA transcripts in diseased human tissue. The human mast cell line HMC-1 was cultured under serum free conditions, stimulated with phorbol mystrate acetate (PMA) and supernatants analyzed by Western blotting and zymography to determine the profile of secreted MMPs. The dog mast cell line BR, known to secrete gelatinolytic enzymes, was used in parallel studies. Total RNA was extracted and analyzed by RT-PCR for the expression of tissue inhibitors of MMP (TIMPs). Collagenase-1 protein and mRNA were expressed by tryptase and chymase positive human mast cells in all tissue analyzed. This proteinase was also detected in the cytoplasm and conditioned media of HMC-1 cells. PMA induced gelatinolytic activity in both mast cell lines examined. TIMP-1 immunoreactivity was detected and TIMP-1, and -2 (but not TIMP-3) mRNA transcripts were amplified from HMC-1 cells. This is the first demonstration of the expression of collagenase-1 by human mast cells in both inflamed and normal tissues, and by a human mast cell line. MMPs secreted by these cells could contribute to the extensive matrix lysis characteristic of diseases such as rheumatoid arthritis and inflammatory ocular disorders. Alternatively collagenase-1 production by mast cells may play a critical role in cell invasion and migration into sites of inflammation.

Endotoxin-induced uveitis is partially inhibited by anti-IL-8 antibody treatment

PURPOSE

To examine the potential therapeutic effect of a neutralizing anti-IL-8 monoclonal antibody in endotoxin-induced uveitis (EIU) in the rabbit.

METHODS

An anti-IL-8 antibody (WS-4) was injected intravitreal 2 hours before, simultaneously with, or 6 hours after endotoxin challenge in rabbits. Eyes were examined for clinical signs of inflammation, and aqueous humor (AH) was sampled to study cellular infiltration and protein content. Leukocyte subset analysis was performed on Giemsa-stained AH cytospins. Histologic grading of inflammation was performed on hematoxylin-eosin-stained sagittal sections of enucleated eyes. In separate experiments, animals received the anti-IL-8 antibody simultaneously with the endotoxin challenge, before repeated anterior chamber paracentesis was performed (at 6, 12, 24, 48, and 72 hours after injection) to estimate the kinetics and durability of changes in total cell count and protein concentration in AH.

RESULTS

Anti-IL-8 therapy caused a decrease in the clinical and histologic grade of inflammation in EIU. The mean cell count in the AH at the peak of inflammation (24 hours) in eyes receiving endotoxin only was 6419+/-1165/microl (mean +/- SE) compared to 2546+/-573/microl in rabbits treated simultaneously with 250 microg of anti-IL-8 antibody (P < 0.05). The protein concentration in the AH was not significantly altered by anti-IL-8 treatment. Kinetic analysis of the leukocyte count in the AH demonstrated persistent inhibition of leukocyte accumulation (range, 60%-91% compared to control eyes) by the anti-IL-8 antibody administered simultaneously with endotoxin. This inhibition was sustained for up to 72 hours after injection.

CONCLUSIONS

Anti-IL-8 antibody treatment partially blocks EIU in rabbits. A consistent decrease in the recruitment of polymorphonuclear leukocytes into the anterior chamber was obtained when neutralizing antibody was injected simultaneously with endotoxin. These findings suggest that IL-8 contributes to the chemotactic signal for the recruitment of leukocytes in EIU.

Ciprofloxacin treatment does not influence course or relapse rate of reactive arthritis and anterior uveitis

OBJECTIVE

To assess the efficacy of ciprofloxacin in the treatment of reactive arthritis (ReA) and anterior uveitis (AU) in a double-blind, randomized, placebo-controlled trial.

METHODS

Seventy-two patients participated in this study, 56 with ReA and 42 with AU (26 patients had both ReA and AU). Ciprofloxacin (750 mg twice a day) was administered for 12 months with a 12-month followup. End points of the study included time to disease relapse and measures of disease severity.

RESULTS

There was no difference between groups in time to disease relapse, joint inflammation, number of joints and enthesis involved in patients with ReA, or signs and symptoms of AU.

CONCLUSION

Long-term treatment of ReA and AU with ciprofloxacin made no statistically significant difference to the natural history of these diseases or their severity.

Culture and characterisation of epithelial cells from human pterygia

BACKGROUND/AIMS

Pterygia are a common disorder of the ocular surface. The disease represents a chronic fibrovascular and degenerative process thought to originate at the conjunctival-corneal junction, where altered limbal stem cells are proposed to be the cell of origin. Extensive epidemiological evidence exists to implicate ultraviolet B irradiation in the pathogenesis of pterygia. To date no animal or in vitro culture model has been developed to test such an hypothesis. The aim of this study was to establish and characterise a pure population of epithelial cells derived from pterygium tissue.

METHODS

Tissue specimens were obtained from patients undergoing pterygium excision. Explants were cultured in either serum free or serum supplemented medium. Primary and passaged cells were processed for light microscopy, analysed by flow cytometry, and characterised immunohistochemically using specific antibodies.

RESULTS

In serum free culture, cuboidal cells with typical morphology of epithelial cells migrated from the pterygium explants from 3 days onwards and eventually formed a cohesive monolayer. Passaged cells consisted of 98.4% cytokeratin positive cells and demonstrated immunoreactivity for multiple cytokeratins, including AE1, AE3, AE5, but were negative for AE8. These cells also expressed an epithelial specific antigen, together with vimentin and mucin, as did epithelial cells in sections of pterygia.

CONCLUSIONS

A relatively simple method of isolating pterygium epithelial cells has been established. Cultured pterygium epithelial cells are phenotypically and functionally similar to their in vivo counterparts with respect to keratin, vimentin, and mucin expression. In vitro assays using these cells may aid in elucidating the pathogenesis of pterygia.

The pathogenesis of pterygia

Pterygium is an active, invasive, inflammatory process, a key feature of which is focal limbal failure. In a two-stage process, "conjunctivalization" of the cornea occurs with tissue characterized by extensive chronic-inflammation, cellular proliferation, connective tissue remodeling, and angiogenesis. An understanding of this process has resulted in efforts aimed at limbal reconstruction, which is considered the gold standard for surgical care. Although good results have been obtained with other treatment methods, a long-term approach to follow-up with at least 5-year survival figures is desirable. Sophisticated analyses of the tear film and surface epithelium in patients with pterygium may help explain symptoms. The efficacy, at least in the short term, of nonsteroidal anti-inflammatory drugs in the treatment of inflamed pterygia has been confirmed. Corneal topographic analysis has shown that surgery reduces induced astigmatism and also causes subtle changes that may explain postsurgical improvements in vision.

Abundant expression of chemokines in malignant and infective human lymphadenopathies

Lymph nodes can be the primary target of infection or malignant transformation and may exhibit characteristic patterns of leukocyte infiltration analogous to those seen in inflammation of other tissues. Leukocyte migration to lymph nodes in vivo is a highly regulated, multi-step process that depends upon adhesion molecules and as yet, uncharacterized chemotactic signals. Chemokines are a key part of the orchestrated code of signals that directs leukocyte subsets to sites of inflammation or immune response. The potential role of these chemoattractants in selective trafficking of leukocyte subsets into lymph nodes was assessed by determining the expression of chemokines on a range of pathological and normal human lymph nodes and by evaluating the cellular composition of each lymph node. In situ hybridization using chemokine riboprobes and immunohistochemistry using specific antibodies were performed in order to correlate the mRNA and protein expression of the chemokines. The cellular source(s) of each chemokine was assessed by immunohistochemical staining of adjacent sections using antibodies directed against distinctive cellular markers. Substantial, but varied, expression of macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, RANTES, macrophage chemotactic protein (MCP)-1, eotaxin, and interleukin 8 (IL-8) were detected in the pathological lymph nodes by diverse cell types. Control lymph nodes showed expression only of RANTES, mainly by high endothelial venules. In all lymph nodes, except the nodes infiltrated with breast cancer, chemokine mRNA expression was highly concordant with the corresponding protein. In contrast with in vitro studies that have suggested discrete target cell specificity of chemokines, this study showed that with the possible exception of the neutrophil chemoattractant, IL-8, no chemokine appeared to be uniquely associated with the accumulation of a specific leukocyte subset. These data implicate chemokines in the recruitment of leukocytes to lymph nodes affected by diverse disease states.

Phenotypic and functional characterization of lymphocytes derived from normal and HIV-1-infected human lymph nodes

Lymph nodes are the major site of cell-to-cell transmission and replication of HIV-1. Trafficking of CD4+ T lymphocytes into lymph nodes provides a continual supply of susceptible target lymphocytes, and conversely, recruitment of CD8+ T lymphocytes may be critical for the host response that attempts to control HIV-1 replication. The present study was undertaken as no detailed assessment of lymphocyte subpopulations in HIV-1-infected lymph nodes has previously been reported. Peripheral blood and single-cell suspensions prepared from lymph nodes of patients with HIV-1 and control subjects were analysed using three-colour flow cytometry. Approximately 80% of the lymphocytes in control lymph nodes were CD3+ T lymphocytes, of which over 65% were CD4+. The majority of the CD4+ and CD8+ T lymphocytes obtained from both lymph nodes and blood of control subjects were immunologically naive (CD45RA+). By contrast, in HIV-1-infected patients there was a significant reduction in the proportion of CD4+ T lymphocytes and an expansion of the CD8+ T lymphocyte subset in both lymph nodes and peripheral blood. Furthermore, a high proportion of these T lymphocytes displayed a marker for immunological memory (CD45RO+). T lymphocytes derived from HIV-1-infected lymph nodes also showed altered expression of the adhesion molecules, L-selectin and very late antigen-4 (VLA-4), but not leucocyte function-associated antigen-1 (LFA-1). In an in vitro adhesion assay, lymphocytes from HIV-1-infected nodes were significantly more adhesive than control lymphocytes on fibronectin, as well as recombinant human intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) substrates. This combination of altered lymphocyte subpopulations in the HIV-1-infected lymph nodes, as well as enhanced adhesion phenotype and function, suggests that T lymphocyte traffic to lymph nodes in HIV disease may be an important determinant of pathogenesis.

Serum immunoglobulin and soluble IL-2 receptor levels in small intestinal overgrowth with indigenous gut flora

Murine studies have demonstrated that the presence of indigenous gut flora is crucial for the induction of systemic immune hyporesponsiveness to antigens initially encountered within the gastrointestinal lumen. This study investigated whether increased titers of such flora, as occur in human small intestinal bacterial overgrowth, may be associated with increased suppression of systemic immune responsiveness and the possible relation between systemic and mucosal immunity in this setting. Serum total immunoglobulin (Ig), immunoglobulin subclass, and soluble interleukin-2 receptor levels and lamina propria IgA plasma cell counts were determined in 50 consecutive subjects with (N = 30) and without (N = 20) small intestinal bacterial overgrowth. Luminal IgA levels were measured in 35 of these subjects. Serum concentrations of IgG3, but not of other immunoglobulin isotypes or soluble interleukin-2 receptors, were significantly reduced in subjects with bacterial overgrowth (P < 0.0005). Small intestinal lamina propria IgA plasma cell counts (P < 0.0005) and luminal IgA concentrations (P = 0.001) were significantly increased in this group. Serum IgG3 levels were significantly inversely correlated with luminal IgA levels (P < 0.01) and fell below the lower limit of normal (0.41 g/liter) in 17/30 (56.7%) subjects with bacterial overgrowth compared to 1/20 (5.0%) subjects without (P < 0.0005). These findings document an association between small intestinal bacterial overgrowth with indigenous gut flora and reduced serum IgG3 reactivity in humans, possibly via an interaction with mucosa-related immunoregulatory mechanisms. The possibility of underlying small intestinal bacterial overgrowth should be considered in patients with serum IgG3 deficiency, especially those with compatible symptoms and/or known predisposition.

Regulation of T lymphocyte trafficking into lymph nodes during an immune response by the chemokines macrophage inflammatory protein (MIP)-1 alpha and MIP-1 beta

By virtue of their target cell specificity, chemokines have the potential to selectively recruit leukocyte subpopulations into sites of inflammation. Their role in regulation of T lymphocyte traffic into lymph nodes during the development of an immune response has not previously been explored. The sensitization phase of contact hypersensitivity induced by the hapten, dinitrofluorobenzene (DNFB) in the mouse was used as a model of T lymphocyte trafficking in response to antigenic stimulation. Rapid accumulation of CD8+ and CD4+ T cells in the draining lymph nodes was closely associated with strongly enhanced expression of macrophage inflammatory protein (MIP)-1 alpha and MIP-1 beta mRNAs and proteins. Mast cells accumulating in the nodes during DNFB sensitization were the predominant source of MIP-1 beta, whereas MIP-1 alpha was expressed by multiple cell types. Neutralization of these chemokines profoundly inhibited T lymphocyte trafficking into lymph nodes and altered the outcome of a subsequent challenge to DNFB. Thus, beta-chemokines regulate T lymphocyte emigration from the circulation into lymph nodes during an immune response and contribute significantly to the immunologic outcome.

Mast cell activation and migration to lymph nodes during induction of an immune response in mice

The mast cell response in skin and lymph nodes was examined during the sensitization phase of dinitrofluorobenzene (DNFB)-induced contact hypersensitivity in mice. Degranulation of 62% of mast cells in DNFB-exposed skin was evident within 30 min of a dual application of DNFB, reaching a peak of 77% at 24 h, and persisting in 42% after 5 d. Abundant expression of macrophage inflammatory protein (MIP)-1alpha and MIP-1beta mRNAs and proteins was observed in keratinocytes, and mast cell degranulation was significantly inhibited after administration of neutralizing antibodies to MIP-1alpha, but not MIP-1beta. During DNFB sensitization, the mast cell density in the skin decreased by half, concurrent with a fivefold expansion of mast cell numbers in draining lymph nodes. Fluorescent-labeled mast cells injected into the skin appeared in draining lymph nodes after application of DNFB, followed by subsequent migration to the spleen. In lymph nodes, mast cells were an abundant and predominant source of MIP-1beta, neutralization of which partially inhibited T lymphocyte recruitment. These results indicate that mast cells contribute to the induction of this primary immune response by activation at and migration from the site of antigen encounter to draining lymph nodes, wherein they mediate T lymphocyte recruitment by production of MIP-1beta.

An akinetic-rigid syndrome, depression, and stereotypies in a young man

A young man is presented who developed an akinetic-rigid syndrome shortly after a minor illness. Rituals and stereoptypies were prominent. At its most severe he was unable to feed himself. There was no response to L-dopa/cardopa treatment. A course of ECT was followed by a marked improvement in his condition. Attempts to stop ECT for more than a week have led to recurrence of his bradykinesia.

Chronic fatigue syndrome: an immunological perspective

OBJECTIVE

The aim of this study is to review research examining an immunological basis for chronic fatigue syndrome (CFS) and to discuss how a disturbance in immunity could produce central nervous system (CNS)-mediated symptoms.

METHOD

Data relevant to the hypothesis that abnormal cytokine release plays a role in the pathogenesis of CFS are reviewed as well as recent evidence relating to potential mechanisms by which immune products may enter the brain and produce a disturbance in CNS processes.

RESULTS

Examinations of cytokine levels in patients with CFS have produced inconclusive results. Recent evidence suggests that abnormal release of cytokines within the CNS may cause neural dysfunction by a variety of complex mechanisms.

CONCLUSION

Neuropsychiatric symptoms in patients with CFS may be more closely related to disordered cytokine production by glial cells within the CNS than to circulating cytokines. This possibility is discussed in the context of unresolved issues in the pathogenesis of CFS.

Chemokine expression and leucocyte infiltration in Sjögren's syndrome

OBJECTIVE

To investigate the expression and source of chemokines in minor salivary gland biopsies (MSGs) in patients with Sjögren's syndrome (SS).

METHODS

Immunohistochemical analysis was used to determine the pattern of chemokine expression in MSGs from patients with (n=6) and without (n=5) SS, as well as to examine the phenotype of both resident and infiltrating cells expressing chemokines.

RESULTS

Significant differences in the number of infiltrating mononuclear (MN) cells in patients with and without SS were noted. Ductal epithelial cells of SS biopsies expressed significantly increased levels of macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, interleukin-8 (IL-8) and RANTES (Regulated upon Activation, Normal T cell Expressed and Secreted). Biopsies from patients with SS showed that MIP-1beta was expressed by 51% of infiltrating cells, while 41% expressed MIP-1alpha, whereas 22 and 7% expressed RANTES and IL-8, respectively.

CONCLUSION

Chemokines expressed by ductal epithelial cells may attract circulating leucocytes, in particular CD4+ T cells, towards the site of inflammation, thereby orchestrating the influx of MN cells characteristically seen in MSGs in SS. Chemokines may be induced directly by a putative triggering agent for SS, or secondary to the release of pro-inflammatory cytokines produced by epithelial cells. These findings further implicate epithelial cells as playing a major role in the pathogenesis of SS and implicate chemokines in the leucocyte recruitment in this setting.

Expression of matrix metalloproteinases by human plasma cells and B lymphocytes

Matrix metalloproteinases (MMP) are proteolytic enzymes that play a key role in tissue remodelling during physiological and pathological processes, by initiating the degradation of extracellular matrix. MMP overexpression can lead to tissue destruction which is characteristic of chronic inflammatory diseases such as rheumatoid arthritis and scleritis. Plasma cells are often abundant at such sites of chronic inflammation. In the present study we investigated whether plasma cells could contribute to matrix degradation by their expression of MMP In situ hybridization and immunohistochemical analyses on diseased synovial and scleral tissue demonstrated the expression of stromelysin-1 (MMP-3) and gelatinase B (MMP-9), but little or no tissue inhibitor of matrix metalloproteinase 1 (TIMP-1) mRNA, by IgG-positive plasma cells. Northern blot analysis of RNA extracted from a human plasma cell line (ARH-77), Epstein-Barr virus-transformed B cells, and purified peripheral blood B cells, demonstrated expression of stromelysin mRNA. TIMP-1 mRNA was only detected by the more sensitive reverse transcription PCR method in these cell types. Plasma cells and B lymphocytes cultured in the presence of monensin demonstrated cytoplasmic gelatinase B. Gelatin and casein zymography on conditioned media (CM) derived from cytokine treated plasma cells revealed the induction of secreted gelatinase and stromelysin activity. Western blotting confirmed the presence of stromelysin-1 and TIMP-1 proteins in plasma cell CM. These data suggest that plasma cells are not only capable of modulating an inflammatory response by antibody and cytokine production, but also by their ability to produce MMP. Secretion of MMP from focal aggregates of plasma cells may play a critical role in tissue destructive diseases such as rheumatoid synovitis and scleritis.

The relationship between fatigue, psychological and immunological variables in acute infectious illness

OBJECTIVE

The aim of this paper is to explore the longitudinal relationships between physical and psychological symptoms and immunological factors following acute infective illnesses.

METHOD

Preliminary data from a prospective investigation of patients with serologically proven acute infectious illnesses due to Epstein-Barr virus (EBV), Ross River virus (RRV) or Q fever are reported. Patients were assessed within 4 weeks of onset of symptoms and then reviewed 2 and 4 weeks later. Physical illness data were collected at interview. Psychological and somatic symptom profiles were assessed by standardised self-report questionnaires. Cell-mediated immune (CMI) function was assessed by measurement of delayed-type hypersensitivity (DTH) skin responses.

RESULTS

Thirty patients who had been assessed and followed over the 4-week period (including 17 patients with EBV, five with RRV and eight with Q fever) were included in this analysis. During the acute phase, profound fatigue and malaise were the most common symptoms. Classical depressive and anxiety symptoms were not prominent. Initially, 46% of cases had no DTH skin response (i.e. cutaneous anergy) indicative of impaired cellular immunity. Over the 4-week period, there was a marked improvement in both somatic and psychological symptoms, although fatigue remained a prominent feature in 63% of subjects. The reduction in reported fatigue was correlated with improvement in the DTH skin response (p = 0.001) and with improvement in General Health Questionnaire (GHQ) scores (p < 0.01).

CONCLUSIONS

Acute infectious illnesses are accompanied by a range of nonspecific somatic and psychological symptoms, particularly fatigue and malaise rather than anxiety and depression. Although improvement in several symptoms occurs rapidly, fatigue commonly remains a prominent complaint at 4 weeks. Resolution of fatigue is associated with improvement in cell-mediated immunity.

Interleukin-6 and small intestinal luminal immunoglobulins

Our aim was to determine the relationships between interleukin-6 and immunoglobulin levels within small intestinal luminal secretions. Twenty adult subjects with small intestinal bacterial overgrowth (N = 13), irritable bowel syndrome (N = 4), and nonulcer dyspepsia (N = 3) underwent endoscopic aspiration of secretions from the small intestinal mucosal surface for assessment of IL-6, IgA1, IgA2, IgM, IgG1, IgG2, IgG3, and IgG4 concentrations. Serum immunoglobulin concentrations and small intestinal histology were also determined. IgA2 and IgG3 were the predominant IgA and IgG subclasses in luminal secretions in 19/20 (95%) and 20/20 (100%) subjects, respectively. IgA1 and IgG1 predominated in serum in all subjects. No subject had villous atrophy. Luminal IL-6 concentrations correlated significantly with luminal IgA2, IgM, and IgG3 concentrations but not with IgA1 or any other IgG subclass levels. Conversely, luminal IL-6 or immunoglobulin concentrations did not correlate significantly with levels of any immunoglobulin isotype in serum. These observations suggest that important relationships exist between local IL-6 and IgA2, IgM, and IgG3 responses in human small intestinal luminal secretions. Local investigation is mandatory when assessing intestinal immune activity.

Chemokines in acute anterior uveitis

PURPOSE

The aim of this study was to define the expression of chemoattractant cytokines (chemokines) in human aqueous humor, obtained from patients with idiopathic acute anterior uveitis (AU). The chemokines assayed included macrophage inflammatory proteins-1 alpha and -1 beta (MIP-1 alpha and -1 beta), monocyte chemoattractant protein-1 (MCP-1), interleukin-8 (IL-8), interferon-inducible protein-10 (IP-10), and regulated on activation, normal T-expressed and secreted (RANTES).

METHODS

We studied fifteen patients (7 females) with idiopathic acute AU, at various stages of disease activity, and two control subjects undergoing elective cataract extraction. Aqueous humor was collected under aseptic conditions, after obtaining informed consent. Chemokine concentrations were measured using specific ELISA. Correlation was sought between chemokine concentrations and disease activity, evaluated by slit lamp biomicroscopy and graded using a standardized scale of disease severity.

RESULTS

IL-8 was detected (35.9 +/- 13.6, mean +/- SE) in three of seven subjects in active, untreated stages of AU (clinical score 2-4), and it was undetectable in subjects sampled in the quiescent phase of the disease. IP-10 had a mean concentration of 40.6 ng/ml +/- 20.9 in the active group (N = 7), declining to 0.8 ng/ml +/- 0.3 in the samples from patients with inactive disease (N = 7, P = 0.001). Similarly, substantial expression of MCP-1 was noted, with a maximum concentration of 145 ng/ml, in acute (active) AU (N = 6), (26.7 +/- 19.7), falling to undetectable levels in those with inactive disease, and in control subjects (P = 0.001). MIP-1 beta (N = 7), (3.4 +/- 1.5, P = 0.001) and RANTES (N = 7, 8.8 +/- 4.2) levels were significantly increased in acute disease (P = 0.001) and related to the activity of the disease, although the concentrations were not as high as MCP-1, IP-10 and IL-8. IP-10, RANTES and MIP-1 beta were detected at low concentrations in the aqueous humor of the control subjects.

CONCLUSIONS

This is the first study of chemokine concentrations in the aqueous humor of patients with acute anterior uveitis. The concentration of chemokines: IL-8, IP-10, MCP-1, RANTES and MIP-1 beta were significantly increased during the active stages of AU, and correlated with the clinical severity of the disease. These chemoattractant cytokines probably play a critical role in leucocyte recruitment in acute AU.

Cognitive deficits in patients suffering from chronic fatigue syndrome, acute infective illness or depression

BACKGROUND

Patients with chronic fatigue syndrome (CFS) report neuro-psychological symptoms as a characteristic feature. We sought to assess cognitive performance in patients with CFS, and compare cognitive performance and subjective workload experience of these patients with that of two disease comparison groups (non-melancholic depression and acute infection) and healthy controls.

METHOD

A computerized performance battery employed to assess cognitive functioning included tests of continuous attention, response speed, performance accuracy and memory. Severity of mood disturbance and subjective fatigue were assessed by questionnaire.

RESULTS

All patient groups demonstrated increased errors and slower reaction times, and gave higher workload ratings than healthy controls. Patients with CFS and non-melancholic depression had more severe deficits than patients with acute infection. All patient groups reported more severe mood disturbance and fatigue than healthy controls, but patients with CFS and those with acute infection reported less severe mood disturbance than patients with depression.

CONCLUSIONS

As all patients demonstrated similar deficits in attention and response speed, it is possible that common pathophysiological processes are involved. The differences in severity of mood disturbance, however, suggest that the pathophysiological processes in patients with CFS and acute infection are not simply secondary to depressed mood.

Spectrum of sarcoidosis involving the eye and brain

PURPOSE

To illustrate the spectrum of sarcoidosis involving the eye and brain and the difficulties of confirming its clinical diagnosis.

METHODS

The presentation of two unusual case reports of patients with ocular and cerebral involvement with sarcoidosis.

RESULTS

Tissue biopsy, an essential component in the differential diagnosis, was required to confirm the diagnosis of sarcoidosis in each patient.

CONCLUSIONS

Sarcoidosis remains an enigmatic disease with protean manifestations and widely differing outcomes.

Luminal antigliadin antibodies in small intestinal bacterial overgrowth

OBJECTIVE

Elevated antigliadin antibody levels in small intestinal luminal secretions of subjects with normal or only mildly abnormal small intestinal histology are considered indicative of "latent" or "potential" celiac disease. The purpose of this study was to determine whether small intestinal bacterial overgrowth (SIBO) might provide an alternative explanation for positive luminal antigliadin antibodies in such subjects.

METHODS

Twenty-six adult subjects without predisposition to disturbed mucosal immunity were investigated with culture of small intestinal luminal secretions. Luminal total IgA and IgA-antigliadin antibody concentrations were measured by radial immunodiffusion and indirect enzyme immunoassay, respectively. Local mucosal counts of IgA-plasma cells were determined by immunohistochemistry. Small intestinal histology and intraepithelial lymphocyte counts were assessed by light microscopy. Corresponding serum antigliadin antibody concentrations were determined.

RESULTS

SIBO was present in 17/26 (65.4%) subjects. No subject with SIBO had villous atrophy. Luminal total IgA concentrations (p < 0.0005), mucosal IgA-plasma cell counts (p < 0.01), and intraepithelial lymphocyte counts (p < 0.01) were significantly increased in subjects with SIBO. Luminal IgA-antigliadin antibodies were detected in 6/17 (35.3%) subjects with SIBO and 0/9 (0%) subjects without SIBO. Luminal IgA-antigliadin antibody concentrations correlated significantly with luminal total IgA levels (p < 0.01) but not with serum values (p < 0.1). Serum IgG-antigliadin antibody concentrations were elevated in 2/6 (33.3%) subjects with SIBO and positive luminal antigliadin antibodies.

CONCLUSIONS

SIBO may be an alternative explanation to "latent" or "potential" celiac disease for positive luminal antigliadin antibodies in subjects with either normal or only mildly abnormal small intestinal histology, even when serum antigliadin antibody concentrations are elevated. Positive luminal antigliadin antibodies in SIBO probably occur as epiphenomena in the context of a graded mucosal immune response to local bacterial antigens.

Intravenous immunoglobulin is ineffective in the treatment of patients with chronic fatigue syndrome

PURPOSE

To determine whether the reported therapeutic benefit of intravenous immunoglobulin in patients with chronic fatigue syndrome (CFS) is dose dependent.

PATIENTS AND METHODS

Ninety-nine adult patients, who fulfilled diagnostic criteria for CFS, participated in this double-blind, randomized, and placebo-controlled trial. Patients received intravenous infusions with either a placebo solution (1% albumin) or one of three doses of immunoglobulin (0.5, 1, or 2 g/kg) on a monthly basis for 3 months, followed by a treatment-free follow-up period of 3 months. Outcome was assessed by changes in a series of self-reported measures (quality-of-life visual analog scales, standardized diaries of daily activities, the profile of mood states questionnaire) and the Karnofsky performance scale. Cell-mediated immunity was evaluated by T-cell subset analysis and delayed-type hypersensitivity (DTH) skin testing.

RESULTS

No dose of intravenous immunoglobulin was associated with a specific therapeutic benefit. Adverse reactions, typically constitutional symptoms, were reported by 70% to 80% of patients, with no relationship to immunoglobulin treatment.

CONCLUSIONS

Intravenous immunoglobulin cannot be recommended as a therapy for the treatment of CFS. A better understanding of the pathophysiology of this disorder is needed before effective treatment can be developed.

Expression of TNF-alpha by human plasma cells in chronic inflammation

Tumor necrosis factor-alpha (TNF-alpha) is a potent pro-inflammatory cytokine and mediator of the inflammatory response. It has been implicated in the pathogenesis of many inflammatory disorders, including rheumatoid arthritis (RA), septic shock, and Crohn's disease. Using a specific anti-human TNF-alpha antibody we detected immunoreactivity for this cytokine in the cytoplasm of inflammatory cells in several chronic inflammatory disorders, including RA, scleritis, and polyarteritis nodosa. These cells were identified predominantly as IgG-expressing plasma cells. Lymph nodes from patients with Hodgkin's lymphoma and breast cancer, but not from control subjects, were also found to contain TNF-alpha-positive plasma cells. Cultured EBV-B lymphocytes and a human plasma cell line (ARH-77) when stimulated with phorbol myristate acetate demonstrated cytoplasmic TNF-alpha immunoreactivity. Western blot analysis of cell membranes and conditioned media from both cell types revealed the presence of the 26-kDa membrane-bound from and the 17-kDa soluble from of TNF-alpha, respectively. TNF-alpha was quantitated by enzyme-linked immunosorbent assay and found to be biologically active as determined by the L929 cytotoxicity assay. This is the first demonstration that plasma cells may be capable of modulating immune and inflammatory responses, not only by antibody production, but also by their secretion of a key inflammatory mediator, TNF-alpha.

Local and systemic complement activity in small intestinal bacterial overgrowth

It is unknown whether bacteriolysis due to luminal complement activation contributes to local defense mechanisms against small intestinal bacterial overgrowth, particularly with gram-negative bacteria. This study addressed this issue. Thirty adult subjects were investigated with culture of luminal secretions adherent to proximal small intestinal mucosa. Luminal and plasma concentrations of C3 and C3d and C3d/C3 ratios were determined. Activated terminal complement complex was sought in surface epithelium to which aspirated secretions had been adherent. Small intestinal bacterial overgrowth with gram-negative bacteria was present in 12/30 (40.0%) subjects. C3, C3d, and C3d/C3 profile indicated that increased local but not systemic C3 activation occurs in this group. Conversely, no activation of terminal complement complex was evident in this circumstance. Thus, complement-mediated bacteriolysis is unlike to contribute to local defense mechanisms against small intestinal bacterial overgrowth, even when overgrowth flora includes gram-negative bacteria. Factors preventing full local activation of the complement cascade in this circumstance require investigation.

Characterisation of follicular dendritic cells in labial salivary glands of patients with primary Sjögren syndrome: comparison with tonsillar lymphoid follicles

OBJECTIVE

To localise and characterise follicular dendritic cells (FDC) present in autoimmune lesions of primary Sjögren syndrome.

METHODS

Cryostat sections of labial salivary glands from 15 patients with primary Sjögren syndrome were examined by an indirect immunoperoxidase technique and monoclonal antibodies to a panel of dendritic cell markers. Tonsils from two controls were also examined for the same markers.

RESULTS

FDC were localised in the centre of 75% of lymphoid focal structures in labial salivary glands biopsies. FDC in labial salivary glands of patients with primary Sjögren syndrome expressed CD35, CD11c, and CD106 (VCAM-1) in a pattern similar to FDC in tonsils, but they did not express either CD14 or CD11b. This indicates that they may not be of myeloid origin, while FDC in tonsillar lymphoid follicles strongly expressed both CD14 and CD11b. FDC in labial salivary glands of patients also lacked VLA-2 alpha and VLA-3 alpha, which were expressed by FDC in tonsils.

CONCLUSIONS

The characteristic phenotype and origin of these cells may be of importance in the immune responses involved in Sjögren syndrome and the retention of infiltrating lymphocytes in the glands.

Molecular biological investigations into the role of the NMDA receptor in the pathophysiology of schizophrenia

OBJECTIVE

There is increasing acceptance that schizophrenia is associated with a generalised disorder in cortical neurodevelopment. The aim of this paper is to review the evidence that this disorder may be accounted for by abnormalities in mechanisms mediated by the main family of excitatory neuroreceptors in cortical brain systems, the N-methyl-D-aspartate (NMDA) glutamatergic receptors.

METHOD

The neurobiological evidence is presented for an abnormality in cortical development related to synaptic pathology in schizophrenia. The unique functions of the NMDA receptor in information processing are described, especially its role in learning and memory, and in neural plasticity and brain development. It is argued that the cellular and molecular mechanisms which underlie learning and memory also govern normal brain development. Studies examining abnormalities in glutamatergic transmission in schizophrenia are reviewed.

RESULTS

There is a substantial literature in support of the possibility that NMDA receptor abnormalities may be involved in the neurodevelopmental predisposition to schizophrenia, as well as in symptom production.

CONCLUSIONS

Research to determine the role of the NMDA receptor in the pathophysiology of schizophrenia is warranted and now feasible. To be successful, this research will require the application of molecular biology techniques to postmortem brain tissue studies, in addition to traditional histochemical approaches.

Utilising molecular biological and histopathological techniques to study the dopaminergic system in patients with melancholia

OBJECTIVE

To describe the rationale for investigating the dopaminergic system in patients with melancholia by applying molecular biological (notably, in situ hybridisation) and histopathological techniques in postmortem brain tissue.

METHOD

Relevant advances in the functional neuroanatomy of frontostriatal circuits, as well as insights from clinical neuroimaging studies in primary and secondary depressive disorders, are presented. These are integrated with developments in the pharmacological and molecular characteristics of dopamine receptor subtypes and recognition of their selective anatomical distribution.

RESULTS

Converging data from the basic and clinical neurosciences suggest that the pathophysiology of depressive disorders characterised by psychomotor phenomena, such as melancholia, may involve dysregulation of dopaminergic mechanisms within complex frontostriatal circuits.

CONCLUSIONS

The key feature of in situ hybridisation is its capacity to test for variations in the functional components of designated biochemical systems within highly specific anatomical regions. We utilise this approach, in combination with relevant histopathological techniques, to test the structural and functional integrity of the dopaminergic system within key fronto-striatal circuits in patients who had exhibited psychomotor phenomena. The same approach can also be used to study the integrity of other relevant biochemical systems, such as the serotoninergic and noradrenergic systems, in patients with other mood disorders.

Increased expression of matrix metalloproteinases in vivo in scleritis tissue and in vitro in cultured human scleral fibroblasts

Scleritis is a sight-threatening inflammatory disorder of the eye characterized by the degradation of scleral matrix. Matrix metalloproteinases (MMPs) are ubiquitous proteolytic enzymes important in physiological and pathological processes, the activity of which is stringently controlled by the action of a family of natural antagonists, the tissue inhibitors of matrix metalloproteinases (TIMPs). We hypothesized that enhanced expression of MMPs, without the negative regulatory influence of TIMPs, may be a key feature of tissue destruction in inflammatory eye diseases, such as scleritis. The aim of this study was to localize and characterize cells expressing MMPs and TIMPs in sclera affected by necrotizing scleritis and, in a parallel study, to establish whether cytokines modulate MMP expression in cultured human scleral fibroblasts. In situ hybridization and immunohistochemical analyses indicated that resident scleral fibroblasts as well as inflammatory cells such as macrophages and T lymphocytes express stromelysin, gelatinase B, and TIMP-1 in necrotizing scleritis tissue. In addition, cytoplasmic immunoreactivity for tumor necrosis factor-alpha, an inducer of MMPs, was detected in infiltrating inflammatory cells. Cultured scleral fibroblasts stimulated with the combination of interleukin-1 alpha plus tumor necrosis factor-alpha increased TIMP-1 mRNA twofold above constitutive levels. By contrast, these cytokines induced a sevenfold increase in the steady-state levels of stromelysin mRNA. Using Western blotting, stromelysin and TIMP-1 protein production paralleled mRNA induction in cytokine-stimulated human scleral fibroblasts. Culture supernatants harvested from cytokine-stimulated human scleral fibroblasts were subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis gelatin substrate zymography. Our results revealed a prominent 92-kd gelatinolytic band corresponding to gelatinase B, which was inducible with interleukin-1 alpha. These data provide evidence for our hypothesis, that an imbalance between enzyme/inhibitor ratios may be the underlying mechanism of the tissue destruction characteristic of scleritis. Our results demonstrate the potential involvement of MMPs and their modulation by cytokines produced by infiltrating inflammatory cells in destructive ocular inflammation.

Molecular biology and the major psychoses

OBJECTIVE

To highlight the potential role of molecular biological studies in examining the expression of genes of interest in brain tissue to elucidate the pathophysiological basis of the major psychoses.

METHOD

To review the principles underlying the available techniques for expression studies.

RESULTS

Detection of messenger RNA by in situ hybridisation and quantitation by Northern analysis are powerful tools to detect abnormalities in gene expression in brain tissue.

CONCLUSION

The availability of simple techniques to examine the expression of RNA and protein products of individual genes, including examination at the level of individual cells, offers a clear opportunity to define the molecular basis of the major psychoses.

Small intestinal bacterial overgrowth in the symptomatic elderly

OBJECTIVE

1) To determine the prevalence of small intestinal overgrowth with colonic-type bacteria in symptomatic elderly subjects, particularly those without important "clues" such as clinically apparent predisposition or vitamin B12 deficiency, and 2) to investigate defense mechanisms such as gastric acidity, small intestinal motility, and luminal IgA in this setting.

METHODS

Fifty-two symptomatic subjects without vitamin B12 deficiency or clinically apparent predisposition to bacterial overgrowth or disturbed mucosal immunity, including 22 subjects > or = 75 yr old, underwent culture of small intestinal luminal secretions. Indicator paper was used to measure fasting gastric pH. The presence of bacteria of confirmed nonsalivary origin in small intestinal secretions served as an index of small intestinal dysmotility. Small intestinal luminal IgA concentrations were measured by radial immunodiffusion.

RESULTS

Small intestinal overgrowth with colonic-type flora was not present in any subject investigated for dyspepsia, irrespective of age. In subjects with chronic diarrhea, anorexia, or nausea, overgrowth with colonic-type flora (Enterobacteriaceae) was present in 0/12 (0%), 1/10 (10.0%), and 9/14 (64.3%) subjects aged < 50 yr, 50-74 yr, and > or = 75 yr, respectively. Enterobacteriaceae were not concurrently recovered from saliva of any subject > or = 75 yr old with small intestinal overgrowth with these bacteria. Fasting hypochlorhydria was present in only 1/9 (11.1%) such subjects. Luminal IgA concentrations were significantly greater in subjects > or = 75 yr old with bacterial overgrowth than in culture-negative subjects (p < or = 0.003).

CONCLUSIONS

Small intestinal overgrowth with colonic-type bacterial should be considered in subjects > or = 75 yr old with chronic diarrhea, anorexia, or nausea, even in the absence of clues such as clinically apparent predisposition or vitamin B12 deficiency. Small intestinal dysmotility, rather than fasting hypochlorhydria or mucosal immunosenescence, probably is responsible for the prevalence of bacterial overgrowth in this group.

Increased production of interleukin-2 (IL-2) but not soluble interleukin-2 receptors (sIL-2R) in unmedicated patients with schizophrenia and schizophreniform disorder

This study investigated immune activation, as measured by production of interleukin-2 (IL-2) and soluble interleukin-2 receptors (sIL-2R) from stimulated lymphocytes, in schizophrenia and schizophreniform disorder. The study included 13 neuroleptic-free patients, 13 medicated patients and 13 age- and sex-matched control subjects. Production of IL-2 and sIL-2R by peripheral blood mononuclear cells (PBMCs) was measured after in vitro stimulation with phytohaemagglutinin (PHA). Patients' symptoms were rated on the Scales for Assessment of Positive (SAPS) and Negative Symptoms (SANS) and the Brief Psychiatric Rating Scale (BPRS). IL-2 production by stimulated lymphocytes was significantly elevated in neuroleptic-free patients compared with both medicated patients and control subjects. IL-2 production was inversely correlated with the SAPS subscales of bizarre behaviour and formal thought disorder. The pattern of increased IL-2 production is in contrast to previous findings in patients with schizophrenia. Significant associations with clinical rating scores suggest that IL-2 production may vary in different biological subgroups of schizophrenia and schizophreniform disorder.

Is there a postinfection fatigue syndrome?

Prolonged fatigue syndromes are common in general practice. Most of these syndromes are secondary to other common medical or psychological disorders. It appears, however, that some specific infectious illnesses are associated with prolonged recovery. Theories as to the mechanisms for such post infection fatigue syndromes include a range of immunological, psychological and neurobiological processes. Current evidence suggests disruption of fundamental central nervous system mechanisms, such as the sleep-wake cycle and the hypothalamic-pituitary-adrenal axis, may underpin the clinical features of this disorder. Treatment should focus on the provision of continuous medical care, physical rehabilitation and adjunctive psychological therapies.

The expression of complement protein 4 and IgG3 in luminal secretions

BACKGROUND

Factors regulating proximal small-intestinal luminal concentrations of IgG3, the predominant IgG subclass at this site, are unclear. This study determined whether luminal IgG3 concentrations are related to those of complement protein 4 (C4), an acute-phase reactant predominantly derived from local mucosa.

METHODS

Proximal small-intestinal luminal and peripheral blood IgG subclass and C4 concentrations were measured by radial immunodiffusion in 30 adult subjects without predisposition to disturbed mucosal immunity. Mucosal C4 immunoreactivity and the presence or absence of small-intestinal bacterial overgrowth were determined in all subjects. Caecal luminal concentrations of IgG3 and C4 were measured in a separate cohort of eight asymptomatic subjects.

RESULTS

Proximal small-intestinal luminal C4 and IgG subclass concentrations were not significantly influenced by the presence of absence of small-intestinal bacterial overgrowth (P > 0.2). Nor did plasma C4 levels significantly influence C4 concentrations in small-intestinal luminal secretions (P > 0.2). Mucosal immunoreactivity for C4 was present in every subject. A significant correlation was found between C4 and IgG3 concentrations in proximal small-intestinal luminal secretions (P < 0.0005) and also in caecal secretions (P < 0.05) but not in peripheral blood (P > 0.1).

CONCLUSIONS

Common factors, not including the presence or absence of small-intestinal bacterial overgrowth, regulate luminal concentrations of C4 and IgG3. Local investigation is mandatory when assessing mucosal immune mechanisms.

Luminal immunity in small-intestinal bacterial overgrowth and old age

BACKGROUND

The independent influences of small-intestinal bacterial overgrowth and old age on mucosal immunoglobulin production and secretion have not been assessed. This is an important issue, since luminal IgA deficiency may exacerbate small-intestinal bacterial overgrowth, the prevalence of which is high in selected elderly populations.

METHODS

Proximal small-intestinal aspirates were obtained from 33 subjects for bacteriologic analysis and measurement of total IgA, IgM, total IgG. IgG subclass, and IgD concentrations. IgA subclasses were measured in 24 unselected subjects. Serum immunoglobulin and salivary IgA concentrations were measured in all subjects.

RESULTS

IgA2 and IgG3 were predominant IgA and IgG subclasses in proximal small-intestinal luminal secretions. Luminal concentrations of IgA2 and IgM, but not IgG3 or any other IgG subclass, were significantly increased in small-intestinal bacterial overgrowth, which was present in 19 of 33 (57.6%) subjects. Old age did not influence these levels. Luminal immunoglobulin concentrations did not correlate significantly with either serum or salivary values. IgD was not measureable in proximal small-intestinal secretions.

CONCLUSIONS

Increased luminal concentrations of the secretory immunoglobulins, IgA2 and IgM, occur in small-intestinal bacterial overgrowth. Local investigation is mandatory when assessing the mucosal immunopathology of this disorder. Luminal IgG3 is unlikely to be predominantly derived from serum. Old age does not independently influence luminal immunity.

Mucosal cytokine production in small-intestinal bacterial overgrowth

BACKGROUND

Mucosal production of interferon-gamma, interleukin-6, and tumour necrosis factor-alpha is increased in inflammatory bowel disease and parallels disease activity. Interferon-gamma production is also increased in coeliac disease. Conversely, local cytokine profiles have not been investigated in small-intestinal bacterial overgrowth. This study addressed this issue.

METHODS

Eighteen adult subjects were studies with culture of proximal small-intestinal luminal secretion and measurement of luminal interferon-gamma, interleukin-6, and tumour necrosis factor-alpha concentrations by enzyme-linked immunosorbent assay. Small-intestinal histology was assessed by light microscopy.

RESULTS

Interferon-gamma, interleukin-6, and tumour necrosis factor-alpha were measurable in proximal small-intestinal luminal secretions of all subjects, even in the absence of light microscopic evidence of enteropathy. Small-intestinal bacterial overgrowth was present in 12 of 18 (66.7%) subjects. Luminal concentrations of neither interferon-gamma nor tumour necrosis factor-alpha differed significantly in subjects with and without small-intestinal bacterial overgrowth (P + 0.06 and P = 1.0, respectively). Conversely, luminal interleukin-6 concentrations were significantly increased in subjects with this disorder (P = 0.02). Multivariate linear regression analysis suggested that colonic-type rather than salivary-type flora mediated this increased interleukin-6 response (P = 0.02 and P = 0.64, respectively). No correlation was found between luminal interleukin-6 and tumour necrosis factor-alpha concentrations, even after the confounding influence of colonic-type bacteria was excluded (P = 0.60).

CONCLUSIONS

These findings suggest that increased mucosal production of interleukin-6 occurs in small-intestinal bacterial overgrowth, particularly when the overgrowth flora includes colonic-type bacteria. Conversely, luminal levels of neither interferon-gamma nor tumour necrosis factor-alpha are increased in the circumstance, distinguishing the local cytokine profile in this disorder from those that occur in coeliac disease and inflammatory bowel disease.

Increased matrix metalloproteinases in the aqueous humor of patients and experimental animals with uveitis

PURPOSE

Matrix metalloproteinases (MMPs) play a major role in connective tissue remodelling, wound healing and embryogenesis. They have also been implicated in pathological tissue degradation in diseases such as rheumatoid arthritis (RA), osteoarthritis (OA), and tumor invasion. The aim of this study was to define the potential role of MMPs in the inflammatory process of uveitis by identifying these proteases in the aqueous humor (AH) of patients with uveitis and in rabbits with endotoxin-induced uveitis (EIU).

METHODS

Aqueous humor samples from 6 patients with uveitis and 5 control patients who had undergone elective cataract surgery were examined. The profile of MMPs in the AH of experimentally-induced acute anterior uveitis in rabbits was also assessed. Western blot analysis and SDS-PAGE substrate zymography were used to detect metalloenzymes and their natural inhibitor, tissue inhibitor of metalloproteinase (TIMP-1) in aqueous samples.

RESULTS

Aqueous humor from all patients contained interstitial collagenase (MMP-1), stromelysin (MMP-3), gelatinase B (MMP-9) and TIMP-1. Although the amount of MMPs varied considerably, TIMP-1 levels remained unchanged in the aqueous of uveitis patients. Using substrate gel zymography, we were able to reveal several gelatinolytic bands, including one major band at approximately 92-kDa whose activity differed between uveitis and cataract AH. The gelatinase activity found in human AH samples was shown to be inhibited by 10 mM EDTA and activated in vitro by APMA, indicating that these enzymes were indeed of the metalloproteinase class. Aqueous humor samples from the rabbit EIU model revealed a 100-kDa molecular weight species likely to correspond to gelatinase B. This gelatinolytic activity was maximal at 6 hours after the lipopolysaccharide (LPS) injection, declined at 12 and 24 hours post LPS, and was absent at later time points. The induction of gelatinase activity in rabbit AH preceded the increase in cell number during the inflammatory process in the anterior chamber.

CONCLUSIONS

Metalloproteinases found in normal human AH may participate in physiological turnover of extracellular matrix in the eye. Elevated levels of MMPs were found in the AH of patients with uveal inflammation and animals with LPS-induced uveitis, where they are likely to be critical to tissue destructive and repair processes. It is likely that pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 alpha (IL-1 alpha), which are known modulators of MMPs, induce their secretion in acute anterior uveitis.

Expression of selectins (CD62 E,L,P) and cellular adhesion molecules in primary Sjögren's syndrome: questions to immunoregulation

Adhesion molecules are important signal transmitters of the immune system and may mediate the homing of leukocytes to sites of inflammation. The aim of this work was to examine the presence of selecting and cellular adhesion molecules on epithelial and endothelial cells in labial salivary glands (LSG) in Sjögren's syndrome (SS). LSG biopsies were obtained from patients with primary SS (n = 31) and normal subjects (n = 21). Cryostat sections were examined with indirect immunoperoxidase. Epithelial cells in LSG from both patients and controls expressed LFA-3 (CD58) and Hermes I (CD44). A significantly increased number of acinar and ductal epithelial cells in LSG from patients expressed class I MHC (74%, as mean percentage of ductal epithelial cells) (P < 0.05), HLA-DR (58%) (P < 0.0001), and HLA-DQ (11%) (P < 0.001). To a lesser extent limited ICAM-1 (CD54) epithelial expression (6%) was noted only in a few biopsies from patients but none of the controls. Epithelial cells did not express any of the selectins CD62 E, L, and P and sometimes they expressed sialyl Le(x) (a ligand for selectins). Although the number of endothelial structures expressing ICAM-1 (CD54), HLA-DR, HLA-DQ, and class I MHC (per surface area) was increased in patients (P < 0.05), this may be due to the total increase of number of endothelial structures (P < 0.05) (Von Willebrand factor +ve) as part of the chronic inflammatory process. A smaller proportion of endothelial structures expressed E-selectin (CD62 E) (32%) and to a lesser extent VCAM-1 (CD106) (approximately 7%) as detectable only in some LSG from patients. P-selectin (CD62 P) was demonstrated on about one-third of endothelial structures in LSG from patients. Infiltrating mononuclear cells expressed CD11a (68%), CD18 (73%), CD11b (13%), CD11c (21%), CD58 (13%), CD4 (44%), CD8 (17%), CD62L (L-selectin) (18%), CD49d (38%), CD49e (15%), CD2 (56%), and CD44 (77%). The relatively reduced number of CD62 L +ve lymphocytes may be due to shedding of that molecule after activation. Sialyl Le(x) was not detectable on infiltrating lymphocytes. Although infiltrating mononuclear cells were activated, as evidenced by their expression of HLA-DR (72%) and ICAM-1 (55%), they did not express IL-2Ralpha (CD25, confirmed by two antibodies 2A3 and ACT1) or IL-2Rbeta (CD122), except rarely (< or = 1%). In some biopsies, CD106 and CD11c were localized on lymphocytes at the central areas of periductal lymphoid follicles with the appearance of dendritic cells. We conclude that adhesion molecules probably play a major role in the pathogenesis of SS. The pattern of expression of these molecules demonstrates a regulated altered activation in the glands associated with this disease. The glands may be subject to specific regulatory factors, in addition to proinflammatory cytokines.

Intravenous immunoglobulin therapy for autoimmune diabetes mellitus

OBJECTIVE

A variety of immune therapies have been used in an attempt to reduce the immune destruction of the insulin secreting beta cells which results in insulin dependent diabetes mellitus (IDDM). This study investigated the use of intravenous gammaglobulin therapy (IVIG) in children and adults with IDDM who participated in a two-year randomised controlled trial which also examined the effect of transfer factor in altering the natural course of IDDM.

METHODS

Treatment was administered every two months for the duration of the study. IVIG was given in a dose of 2 g/ kg body weight in divided doses over two days. The other two groups received an intramuscular injection-the control group received normal saline and the transfer factor group received 1 i.u. of transfer factor. Remission rates, beta cell function and treatment side effects were assessed.

RESULTS

Compared with the control group, IVIG therapy given every 2 months for 2 years, did not result in an increased number of complete remissions or differences in insulin dose, diabetes control or endogenous insulin secretion assessed as fasting and stimulated C-peptide responses to glucagon and a meal. IVIG therapy was associated with significant side effects.

CONCLUSION

It is unlikely that IVIG therapy will be a viable option for immunotherapy in IDDM.

Chemokines and T lymphocyte recruitment to lymph nodes in HIV infection

Recruitment of T lymphocytes to lymph nodes in patients with HIV infection is critical to the pathogenesis of disease. Chemokines are a family of cytokines, which are potent regulators of leukocyte migration. We studied the leukocyte populations and expression of chemokines known to be active upon T cells in lymph nodes of four HIV infected patients and seven control subjects using in situ hybridization, immunohistochemistry, and FACS analysis. The HIV lymph nodes showed CD8+ T lymphocyte accumulation and strongly enhanced chemokine expression, notably for the CD8+ T cell chemoattractant, macrophage inflammatory protein (MIP)-1 alpha. Resident macrophages appeared to be a major cellular source of chemokines in the HIV nodes. RANTES expression was present in both HIV and control lymph nodes, suggesting a physiological role for this chemokine in T lymphocyte recirculation. Chemokines may be important determinants of T lymphocyte accumulation in lymphoid tissue of patients with HIV/AIDS.

Modulation of endothelial cell expression of ICAM-1, E-selectin, and VCAM-1 by beta-estradiol, progesterone, and dexamethasone

The aim of this study was to examine the effects of beta-estradiol, progesterone, and dexamethasone on cytokine-stimulated endothelial cell expression of adhesion molecules. TNF-alpha (250 U/mL) and IL-1 alpha (50 U/mL) were used to stimulate the endothelial cells for 6 or 23 hr in vitro. Indirect immunofluorescence and flow cytometry were used to quantitate expression of adhesion molecules. After 6 hr stimulation with TNF-alpha increased expression of E-selectin (P < 0.03) was noted with beta-estradiol. Strong suppression of ICAM-1 (P < 0.005) and E-selectin (P < 0.005) expression was evident with dexamethasone, which did not influence VCAM-1 expression. After 6 hr stimulation with IL-1 alpha suppression of E-selectin was observed with progesterone (P < 0.001). Dexamethasone had strong suppressive effects on ICAM-1 (P < 0.001), E-selectin (P < 0.0001), and VCAM-1 (P < 0.0002). After 23 hr stimulation with IL-1 alpha or TNF-alpha none of the examined steroids showed a significant effect on the fluorescence intensity of adhesion molecules, although there was a slight increase of the percentage of ICAM-1 positive cells with high concentrations of beta-estradiol after stimulation with TNF-alpha. Beta-estradiol and progesterone are modulatory factors of E-selectin expression on endothelial cell in vitro. Dexamethasone reduces adhesion molecule expression over endothelial cells after cytokine stimulation. These effects may be important in understanding the role of these steroids in autoimmune diseases.

Lessons in cooperation: four hospital consortia relate their quality improvement experiences

BACKGROUND

In 1989, The Robert Wood Johnson Foundation launched a demonstration project to test a consortium approach to quality improvement. As part of this project, four hospital consortia in various parts of the United States are currently sharing quality resources (for example, training) and collaborating on various improvement efforts. The purpose of the project is to demonstrate that hospitals can take on more difficult problems and accomplish more in cooperation with each other than on their own.

CASE STUDIES

The Institute for Quality Healthcare (Iowa City, Iowa) has built a comparative database so that 40 member hospitals can make meaningful comparisons on various aspects of performance; The Vermont Program for Quality in Health Care has lowered the postoperative infection rate in Vermont by monitoring compliance with consensus guidelines; Interwest Quality of Care, Inc, which has member organizations in Utah, Wyoming, and Idaho, has adapted and disseminated guidelines for diabetic care; and The Public Hospital Institute, in Berkeley, California, has worked with the Joint Commission on Accreditation of Healthcare Organizations to develop a written guide to help surveyors understand the unique operational traits of public hospitals.

LESSONS LEARNED

Projects such as those with champions in several member organizations and comparative data analysis lend themselves more easily to cooperative work than others. They also provide some strategies for collaboration, such as continually reinforcing the principles of collaboration, obtaining a fully informed commitment, beginning with initiatives that are likely successes, and being serious and vocal about the commitment to confidentiality.

CONCLUSIONS

Collaborators in quality improvement gain important resources, such as better information, more relevant reference databases, colleagues and support for quality improvement specialists, and economies of scale in education programs, training materials, and interaction with vendors. However, the difficulties in collaboration are great. Hospitals must continually consider not only "What's in this for me," but also "What can we accomplish as a group that is greater than what each of us can do alone?"

Chronic fatigue syndrome: current perspectives on evaluation and management

OBJECTIVE

To describe clinical and laboratory guidelines for assessment and management of patients presenting with chronic fatigue syndrome (CFS).

DATA SOURCES

Relevant international consensus diagnostic criteria and research literature on the epidemiology, pathophysiology, concurrent medical and psychological disturbance and clinical management of CFS.

CONCLUSIONS

Medical and psychiatric morbidity should be carefully assessed and actively treated, while unnecessary laboratory investigations and extravagant treatment regimens should be avoided. No single infective agent has been demonstrated as the cause of CFS, and immunopathological hypotheses remain speculative. The aetiological role of psychological factors is debated, but they do predict prolonged illness. The rate of spontaneous recovery appears to be high. Effective clinical management requires a multidisciplinary approach, with consideration of the medical, psychological and social factors influencing recovery.

Can the chronic fatigue syndrome be defined by distinct clinical features?

To determine whether patients diagnosed as having chronic fatigue syndrome (CFS) constitute a clinically homogeneous class, multivariate statistical analyses were used to derive symptom patterns and potential patient subclasses in 565 patients. The notion that patients currently diagnosed as having CFS constitute a single homogeneous class was rejected. An alternative set of clinical subgroups was derived. The validity of these subgroups was assessed by sociodemographic, psychiatric, immunological and illness behaviour variables. A two-class statistical solution was considered most coherent, with patients from the smaller class (27% of the sample) having clinical characteristics suggestive of somatoform disorders. The larger class (73% of sample) presented a more limited combination of fatigue and neuropsychological symptoms, and only moderate disability but remained heterogeneous clinically. The two patient groups differed with regard to duration of illness, spontaneous recovery, severity of current psychological morbidity, utilization of medical services and CD8 T cell subset counts. The distribution of symptoms among patients was not unimodal, supporting the notion that differences between the proposed subclasses were not due simply to differences in symptom severity. This study demonstrated clinical heterogeneity among patients currently diagnosed as CFS, suggesting aetiological heterogeneity. In the absence of discriminative clinical features, current consensus criteria do not necessarily reduce the heterogeneity of patients recruited to CFS research studies.

Delayed-type hypersensitivity skin testing: normal values in the Australian population

In our human psychoimmunological studies we have utilized a standardized assessment kit, the cell-mediated immunity (CMI) Multitest system, for determining delayed-type hypersensitivity (DTH) skin responses to a panel of ubiquitous antigens. Although the kit had been assessed in large populations of healthy controls in the U.S.A. and Europe, few data were available with regard to normative values in the Australian population. There are cogent reasons to suspect that results for the test will vary depending on geographical location, age cohort, compliance with specific immunization schedules and rates of natural exposure to certain diseases in differing populations. Most of our patient cohorts have a preponderance of female subjects and most standardization had been conducted in males. We tested medically and psychologically healthy males (n = 66) and females (n = 53). The percentage of positive responses to individual antigens was similar to other Australian studies but lower than that reported internationally. The mean number of positive responses was 3.7 for men and 2.8 for women, while the mean induration diameter was 17.5 mm for men and 12.2 mm for women. Three per cent of men and 5.6% of women were anergic (no positive responses), while a further 10.6% of men and 9.4% of women fell into the "hypoergic" category. These results, and those from other studies, indicate that the pattern of response to the CMI Multitest differs in healthy Australians. Therefore, researchers need to exercise caution when selecting patient and control samples (controlling for exposure factors), applying the test, reporting results (i.e. including all relevant parameters-with an emphasis on dimensional rather than categorical scores) and when designating subjects as having "impaired" responses.