Gold and D-penicillamine induce vasculitis and up-regulate mRNA for IL-4 in the Brown Norway rat: support for a role for Th2 cell activity

Hep-2 cell based indirect immunofluorescence assay for antinuclear antibodies as a potential diagnosis of drug-induced autoimmunity in nonclinical toxicity testing

Antinuclear antibodies (ANAs) are important biomarkers in the diagnosis of autoimmune diseases in humans; however, the diagnostic performance of ANA in nonclinical safety studies are not well understood. Here, we studied the use of ANAs as potential nonclinical biomarkers for drug-induced autoimmunity (DIA) using a Hep-2 based indirect immunofluorescence assay (IFA). Initially, MRL-fas(lpr)/J mice and HgCl₂-treated rats were used as SLE-positive models. Serum samples obtained from 94 normal mice or 204 normal rats aged one to four months served as the negative control. The IFA effectively distinguished ANAs-positive samples in both species with a cut-off titer of 1:100. Brown Norway rats were treated with 450 mg/kg D-penicillamine for 30 consecutive days. ANAs were generated and corresponded with DIA development. Human Hep-2 cells, mice Neuro 2A cells, and Chinese Hamster Lung cells served as antigen from different species, which were found cross-reactive with ANA-positive serum samples from mice, rats, and humans without any differences in diagnosis. This methodology showed no species-specificity for ANA detection. Furthermore, we found approximately 20 percentage of the mice aged seven to eight months demonstrated age-related ANAs, which was consistent with humans. Overall, our findings demonstrated the use of ANA detection using IFA in the nonclinical diagnosis of murine drug-induced autoimmunity, and age-related ANAs should be considered when aged animals are used.

Use of tissue Doppler and its comparison with other pulse Doppler echocardiography in the evaluation of diastolic functions in patients with active juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is a systemic chronic inflammatory disease. Cardiac involvement as pericarditis, myocarditis and valvular disease is common in JIA. This study aims to assess left ventricular (LV) diastolic functions with tissue Doppler imaging (TDI) and to compare it with conventional Doppler echocardiography (pulse wave Doppler (PWD)) techniques in patients with active JIA. Forty-five patients with active JIA and 47 healthy age- and sex-matched controls were included in this study. Duration of disease ranged from 6 to 138 months (mean 49.59 ± 31.25 months). In addition to PWD echocardiographic methods, TDI was performed to assess LV functions in all participants. On PWD echocardiography analysis, the JIA group had lower peak E velocity (p < 0.001), higher peak A velocity (p < 0.001) and more prolonged isovolumic relaxation time (IVRT) (p = 0.02). E/A ratio was found to be lower in patients with JIA than that in the control group (p < 0.001). Patients with JIA had a much higher E velocity trace integral (VTI) and A VTI when compared to controls (respectively p = 0.03, p = 0.04). Mitral annular early diastolic velocity (Em), among TDI parameters, was found to be lower in patients with JIA than that in the control group (p < 0.001). Em/Am (mitral annular late diastolic velocity) ratio was found to be lower in JIA patients compared with that in the control group (p < 0.001). There was an increase in IVRT in JIA patients compared to control group (p = 0.04). Though Em VTI was similar in the two groups, patients with JIA had a much higher Am VTI when compared to controls (respectively p = 0.48, p < 0.001). E/Em ratio was higher in patients with JIA than in the control group (p < 0.05). LV diastolic functions were impaired in patients with active JIA, in the absence of clinical evidence of cardiac disease. We have concluded that TDI solo, or jointly with PWD echocardiography, is valuable for the evaluation of diastolic functions in active JIA patients.

Animal models used to examine the role of the environment in the development of autoimmune disease: findings from an NIEHS Expert Panel Workshop

Autoimmunity is thought to result from a combination of genetics, environmental triggers, and stochastic events. Environmental factors, such as chemicals, drugs or infectious agents, have been implicated in the expression of autoimmune disease, yet human studies are extremely limited in their ability to test isolated exposures to demonstrate causation or to assess pathogenic mechanisms. In this review we examine the research literature on the ability of chemical, physical and biological agents to induce and/or exacerbate autoimmunity in a variety of animal models. There is no single animal model capable of mimicking the features of human autoimmune disease, particularly as related to environmental exposures. An objective, therefore, was to assess the types of information that can be gleaned from the use of animal models, and how well that information can be used to translate back to human health. Our review notes the importance of genetic background to the types and severity of the autoimmune response following exposure to environmental factors, and emphasizes literature where animal model studies have led to increased confidence about environmental factors that affect expression of autoimmunity. A high level of confidence was reached if there were multiple studies from different laboratories confirming the same findings. Examples include mercury, pristane, and infection with Streptococcus or Coxsackie B virus. A second level of consensus identified those exposures likely to influence autoimmunity but requiring further confirmation. To fit into this category, there needed to be significant supporting data, perhaps by multiple studies from a single laboratory, or repetition of some but not all findings in multiple laboratories. Examples include silica, gold, TCE, TCDD, UV radiation, and Theiler's murine encephalomyelitis virus. With the caveat that researchers must keep in mind the limitations and appropriate applications of the various approaches, animal models are shown to be extremely valuable tools for studying the induction or exacerbation of autoimmunity by environmental conditions and exposures.

The role of cytokines in the mechanism of adverse drug reactions

Cytokines are thought to play a role in acute and/or immune-mediated adverse drug reactions (ADRs) due to their ability to regulate the innate and adaptive immune systems. This role is highly complex owing to the pluripotent nature of cytokines, which enables the same cytokine to play multiple roles depending on target organ(s) involved. As a result, the discussion of cytokine involvement in ADRs is organized according to target organ(s); specifically, ADRs targeting skin and liver, as well as ADRs targeting multiple organs, such as drug-induced autoimmunity and infusion-related reactions. In addition to discussing the mechanism(s) by which cytokines contribute to the initiation, propagation, and resolution of ADRs, we also discuss the usefulness and limitations of current methodologies available to conduct such mechanistic studies. While animal models appear to hold the most promise for uncovering additional mechanisms, this field is plagued by a lack of good animal models and, as a result, the mechanism of cytokine involvement in ADRs is often studied using less informative in vitro studies. The recent formation of the Drug-Induced Liver Injury Network, whose goal is collect thousands of samples from drug-induced liver injury patients, has enormous potential to advance knowledge in this field, by enabling large-scale cytokine polymorphism studies. In conclusion, we discuss how further advances in this field could be of significant benefit to patients in terms of preventing, predicting, and treating ADRs.

P wave dispersion in patients with rheumatoid arthritis: its relation with clinical and echocardiographic parameters

P wave dispersion (PWD) is a sign for the prediction of atrial fibrillation (AF). The aim of this study was to assess P wave dispersion and its relation with clinical and echocardiographic parameters in patients with rheumatoid arthritis (RA). Thirty RA patients (mean age 49 +/- 10 years) and 27 healthy controls (mean age 47 +/- 8 years) were included in the study. We performed electrocardiography and Doppler echocardiography on patients and controls. Maximum and minimum P wave duration were obtained from electrocardiographic measurements. PWD defined as the difference between maximum and minimum P wave duration was also calculated. Maximum P wave duration and PWD was higher in RA patients than controls (P = 0.031 and P = 0.001, respectively). However, there was no significant difference in minimum P wave duration between the two groups (P = 0.152). There was significant correlation between PWD and disease duration (r = 0.375, P = 0.009) and isovolumetric relaxation time (r = 0.390, P = 0.006). P wave duration and PWD was found to be higher in RA patients than healthy control subjects. PWD is closely associated with disease duration and left ventricular (LV) diastolic dysfunction.

Right ventricular diastolic abnormalities in rheumatoid arthritis and its relationship with left ventricular and pulmonary involvement. A tissue Doppler echocardiographic study

OBJECTIVES

To investigate right ventricular diastolic function in rheumatoid arthritis (RA) and its relationship with left ventricular and pulmonary involvement.

METHODS

Thirty-five RA patients and 30 healthy subjects were submitted to conventional Doppler (CE) and tissue Doppler echocardiography (TDE) to assess left and right systolic and diastolic function and to estimate maximal arterial systolic pulmonary pressure (PAP). To detect pulmonary involvement, pulmonary function tests and high-resolution computed tomography (HRCT) scans were performed in all RA patients.

RESULTS

An abnormal RV filling, as expressed byan inverted tricuspid (Tr.) E/A ratio, was detected in 12 (34%) of the 35 RA patients and in 2 (7%) of the 30 controls (P<0.004). If compared to CE findings, prevalence of RV diastolic abnormalities were found higher in patients with RA by TDE (RV annulus Em/Am ratio <1 (in 31 (89%) of 35 patients) (P = 0.002). Twenty-two (63%) of 35 patients had abnormal HRCT findings. Pulmonary involvement with pulmonary hypertension (PHT) (36+/-5 mmHg) was detected in 10 (29%) of 35 RA. In this group, increase of RV annulus and basal Am wave, decrease of Tr. E/A ratio and RV annulus Em/Am ratio were statistically significant compared to RA (12 (34%) of 35) patients with pulmonary involvement who had normal PAP (19+/-5 mmHg), (P = 0.014, P = 0.006, P = 0.015, P = 0.049, respectively).

CONCLUSIONS

This study points out an impaired RV filling in a significant part of RA patients without overt heart failure. Impairment of RV diastolic function may be a predictor of subclinic myocardial and pulmonary involvement in patients with RA.

Diastolic function abnormalities in active rheumatoid arthritis evaluation by conventional Doppler and tissue Doppler: relation with duration of disease

OBJECTIVE

The aim of this study was to evaluate left ventricular diastolic function in patients with active rheumatoid arthritis (RA), analyzing conventional Doppler and tissue Doppler echocardiographic imaging (TDI) which is a new echocardiographic application, with special regard to disease duration.

METHODS

Fifty-two patients with active RA and 47 healthy persons were included in this study. Duration of disease ranged from 3 to 324 months (mean 76+/-85 months). All patients and the control group were evaluated by M-mod, two-dimensional, conventional Doppler echocardiography and TDI.

RESULTS

Among conventional Doppler transvalvular mitral flow parameters, late diastolic flow velocity (A) and deceleration time (DT) values were higher in patients with RA than that in the control group (p<0.001). E (early diastolic flow velocity)/A ratio was found to be lower in patients with RA than that in the control group (p<0.001). Mitral annular early diastolic velocity (E (m)), among TDI parameters, was found to be lower in patients with RA than that in the control group (p<0.001). E (m)/A (m) (mitral annular late diastolic velocity) ratio was found to be lower in RA patients compared with that in the control group (p<0.001). The relation was found between A (r=0.43, p=0.001), DT (r=0.30, p=0.03), E/A ratio (r=0.40, p=0.004), E (m) (r=0.32, p=0.02), E (m)/A (m) ratio (r=0.30, p=0.03), and E/E (m) (r=0.32, p=0.02), with disease duration in patients with RA.

CONCLUSION

At present, it is concluded that active RA patients, in the absence of clinical evidence of heart disease, show diastolic dysfunction characterized by impaired E/A ratio, E (m)/A (m) ratio, and DT. The relation between diastolic dysfunction and disease duration suggests a subclinical myocardial involvement.

Use of tissue Doppler and its comparison with other conventional Doppler techniques in the assessment of diastolic functions in patients with active rheumatoid arthritis

OBJECTIVE

This study aims to assess left ventricular diastolic functions with tissue Doppler imaging (TDI), which is a new technique, and to compare it with conventional Doppler echocardiography techniques in patients with active rheumatoid arthritis (RA).

METHODS

Fifty-two patients with active RA and 47 healthy persons were included in this study. All patients and the control group were evaluated by M-mod, two-dimensional, conventional Doppler echocardiography and TDI.

RESULTS

Left ventricular early diastolic (E)/late diastolic (A) flow velocity (E/A ratio) was found to be lower in patients with RA than in the control group (p<0.001). Mitral annular early diastolic (E(m))/late diastolic (A(m)) velocity(E(m)/A(m) ratio) was found to decrease in RA patients compared with the control group (p<0.001). E/E(m) ratio was higher in patients with RA than in the control group (p<0.001).

CONCLUSION

Left ventricular diastolic functions were impaired in patients with RA. We have concluded that TDI alone, or together with conventional Doppler echocardiography, is useful for the evaluation of diastolic functions in RA patients.

How to diagnose and treat secondary forms of vasculitis

Vasculitis is considered to be secondary when it arises either in the context of a pre-existing connective tissue disease, as a result of direct infection with a limited range of organisms, especially viruses, or when it arises in response to exposure to a number of medications. Rheumatoid vasculitis is probably the most widely recognised form of secondary vasculitis, and in this article we review the incidence, clinical features and management of this condition. Infections may either trigger or cause some types of vasculitis. Drug therapy is a common cause of limited forms of vasculitis and may enhance our understanding of the mechanism of these diseases. The premature development of atherosclerosis in patients with existing connective tissue diseases or indeed primary vasculitis has been recognised for some time, and the underlying mechanisms are currently being studied. An appreciation of the complex and varied pathophysiology of secondary vasculitis may further our understanding of primary vasculitis.

Ventricular function abnormalities in active rheumatoid arthritis: a Doppler echocardiographic study

OBJECTIVE

The aim of the present study was to evaluate cardiac involvement in patients with active rheumatoid arthritis (RA).

METHODS

Forty patients with active RA participated. All were submitted to standard Doppler echocardiography and myocardial performance index (MPI) grading.

RESULTS

There were left and right ventricular diastolic function abnormalities in RA patients. Left ventricular MPI was also significantly higher than in controls ( P<0.05). A relationship was found between left ventricular early diastolic (E)/atrial (A) flow velocities (E/A ratio), isovolumic relaxation time (IRT), and disease duration ( r=-0.47 and P=0.002, r=0.618 and P=0.000, respectively).

CONCLUSION

Diastolic function was impaired in both ventricles in patients with active RA. There was a direct relationship between some of the parameters of left ventricular diastolic function and disease duration as well. These findings suggest a subclinical myocardial involvement in RA patients.

Predictive testing for autoimmunity

Many chemicals, in particular drugs, cause systemic allergy or autoimmune-like disorders. Due to complex pathogenesis and strong dependence on genetic make-up, these immunotoxicological effects are usually missed in standard toxicity testing. Besides, animal studies that demonstrate chemically induced systemic allergy or autoimmune-like disorders are scarce. Here, animal models are presented that would fit into a predictive two-tiered strategy, designed to allow screening for immunostimulatory potential in the first tier, and more elaborate testing for allergenic or autoimmunogenic potential of selected chemicals in the second tier. The popliteal lymph node assay (PLNA), with or without reporter antigens, would fit in the first tier, and relevant route of exposure protocols with selected strains of mice or rats may be further developed to compose the second tier. To date, the relevant route of exposure models mentioned here (with 'normal' inbred mice and/or Brown Norway rats) has been tested with only a few chemicals, and the PLNA, although tested with over 100 chemicals, is not validated as yet. Conceivably, a major challenge in immunotoxicology is to incorporate the present knowledge on chemical-induced systemic allergy and autoimmunity in further development and validation of predictive models and strategies.

Delayed cerebrovascular complications of intrathecal colloidal gold

OBJECTIVE

Therapy with intrathecal colloidal gold has been used in the past as an adjunct in the treatment of childhood neoplasms, including medulloblastoma and leukemia. We describe the long-term follow-up period of a series of patients treated with intrathecal colloidal gold and emphasize the high incidence of delayed cerebrovascular complications and their management.

METHODS

Between 1967 and 1970, 14 children with posterior fossa medulloblastoma underwent treatment at the University of Minnesota. Treatment consisted of surgical resection, external beam radiotherapy, and intrathecal colloidal gold. All patients underwent long-term follow-up periods.

RESULTS

Of the 14 original patients, 6 died within 2 years of treatment; all experienced persistent or recurrent disease. The eight surviving patients developed significant neurovascular complications 5 to 20 years after treatment. Three patients died as a result of aneurysmal subarachnoid hemorrhage, and five developed ischemic symptoms from severe vasculopathy that resembled moyamoya disease.

CONCLUSION

Although therapy with colloidal gold resulted in long-term survival in a number of cases of childhood medulloblastoma, our experience suggests that the severe cerebrovascular side effects fail to justify its use. The unique complications associated with colloidal gold therapy, as well as the management of these complications, are presented. We recommend routine screening of any long-term survivors to exclude the presence of an intracranial aneurysm and to document the possibility of moyamoya syndrome.

Effects of IL-4 and IL-12 on experimental immune-mediated blepharoconjunctivitis in Brown Norway rats

IL-12 and IL-4 are critical cytokines for Th1 and Th2 differentiation, respectively. To assess the roles of these cytokines in the development of experimental immune-mediated blepharoconjunctivitis (EC) in Brown Norway (BN) rats, their effects were tested either in vitro or in vivo. Draining lymph node cells from rats immunized with ragweed pollen (RW) in Al(OH)3 were collected and cultured for 3 days with RW in the presence of IL-4, IL-12, or PBS as a control. After harvesting the culture supernatants for cytokine ELISA and the cells for cytokine reverse transcriptase-polymerase chain reaction, 10 million cells were injected intravenously into syngeneic recipient rats (n = 12 per group). The rats were challenged with RW by eye drops 4 days after transfer. Eyes were harvested for histology 24 h later. Furthermore, IL-12 (500 ng per injection) or PBS was injected intraperitoneally every other day seven times from the day of active immunization (n = 6 per group). One day after the last injection, rats were challenged and EC was evaluated as above. Transfer of cells with IL-4 in vitro augmented eosinophilic infiltration in the conjunctiva compared with the other two groups, whereas IL-12 in vitro suppressed eosinophilic infiltration and increased lymphocytic infiltration. Interferon-gamma production was augmented by IL-12. IL-4 RNA expression was augmented by IL-4. IL-12 administration in vivo augmented lymphocytic infiltration in the conjunctiva without affecting infiltration of eosinophils. In conclusion, IL-4 and IL-12 either in vitro or in vivo augmented Th2 and Th1 immunity, respectively, thus leading to distinct histological features of EC.

CD30+ T cells in rheumatoid synovitis: mechanisms of recruitment and functional role

High serum levels of soluble CD30 (sCD30) have been reported to better predict the response to second line therapy in rheumatoid arthritis (RA). It is believed that sCD30 is released by CD30+ T cells present in the RA synovium. However, both the mechanism of recruitment to the joint and the functional role of this T cell subset in the pathogenesis of the disease remain unknown. This study confirmed higher levels of sCD30 in the serum and synovial fluid (SF) of RA patients compared with normal controls. However, analysis of mRNA and cell surface CD30 expression showed that CD30+ T cells are detectable in the SF, but not in the synovial membrane. In contrast, T cells expressing the CD30 transcript, but not the surface molecule, were found in the peripheral blood of both RA and normal controls. CD30 surface expression was up-regulated by adhesion and migration through endothelium in vitro and in a delayed-type hypersensitivity model in vivo. Although the great majority of fresh or cloned CD30+ T cells from SF produced both IFN-gamma and IL-4, CD30 expression strictly correlated with IL-4 synthesis in synovial T cell clones. In addition, CD30+ T cell clones also produced high amounts of the anti-inflammatory cytokine IL-10. On this basis, we would like to propose that synovial CD30+ cells may play a role in the control of the inflammatory response. Serum sCD30 may reflect such cell activity and, therefore, explain the previously demonstrated correlation between high sCD30 serum levels and positive response to therapy.

Soluble CD30 in early rheumatoid arthritis as a predictor of good response to second-line therapy

OBJECTIVE

To evaluate whether serum levels of the soluble form of CD30 (sCD30) correlate with disease activity in early rheumatoid arthritis (RA) and may have prognostic value in predicting the response to disease-modifying anti-rheumatic drugs (DMARDs).

METHODS

The levels of sCD30 and C-reactive protein (CRP) were measured in the serum of 14 untreated subjects with early RA, before and during treatment with hydroxychloroquine, for a follow-up period of 8 months. At the end of the study, patients were also evaluated for their response to DMARDs.

RESULTS

An inverse correlation between sCD30 and CRP serum values was demonstrated at baseline, but not during the follow-up. Patients who responded to DMARD therapy had higher sCD30 basal levels than non-responders.

CONCLUSIONS

The evaluation of sCD30 serum levels in early RA may reflect the attempt by CD30+ T cells to downmodulate inflammation and may be a useful marker to predict a good response to DMARDs.

Metals and kidney autoimmunity

The causes of autoimmune responses leading to human kidney pathology remain unknown. However, environmental agents such as microorganisms and/or xenobiotics are good candidates for that role. Metals, either present in the environment or administered for therapeutic reasons, are prototypical xenobiotics that cause decreases or enhancements of immune responses. In particular, exposure to gold and mercury may result in autoimmune responses to various self-antigens as well as autoimmune disease of the kidney and other tissues. Gold compounds, currently used in the treatment of patients with progressive polyarticular rheumatoid arthritis, can cause a nephrotic syndrome. Similarly, an immune-mediated membranous nephropathy frequently occurred when drugs containing mercury were commonly used. Recent epidemiologic studies have shown that occupational exposure to mercury does not usually result in autoimmunity. However, mercury induces antinuclear antibodies, sclerodermalike disease, lichen planus, or membranous nephropathy in some individuals. Laboratory investigations have confirmed that the administration of gold or mercury to experimental animals leads to autoimmune disease quite similar to that observed in human subjects exposed to these metals. In addition, studies of inbred mice and rats have revealed that a few strains are susceptible to the autoimmune effects of gold and mercury, whereas the majority of inbred strains are resistant. These findings have emphasized the importance of genetic (immunogenetic and pharmacogenetic) factors in the induction of metal-associated autoimmunity. (italic)In vitro(/italic) and (italic)in vivo(/italic) research of autoimmune disease caused by mercury and gold has already yielded valuable information and answered a number of important questions. At the same time it has raised new issues about possible immunostimulatory or immunosuppressive mechanisms of xenobiotic activity. Thus it is evident that investigations of metal-induced renal autoimmunity have the potential to produce new knowledge with relevance to autoimmune disease caused by xenobiotics in general as well as to idiopathic autoimmunity.

Anti-idiotype immunomodulation of experimental anti-phospholipid syndrome via effect on Th1/Th2 expression

Mice with experimental anti-phospholipid syndrome (APS), induced by active immunization with a human anti-cardiolipin MoAb (H-3), were treated with mouse anti-idiotypic MoAb (anti-H3, named S2.9) and with an irrelevant anti-idiotype. The immunized mice produced high titres of mouse anti-cardiolipin antibodies along with clinical manifestations of experimental APS: prolonged activated partial thromboplastin time (aPTT), thrombocytopenia and high rate of fetal loss. Treatment with the specific anti-Id (S2.9) as a whole molecule or F(ab)2 fraction, resulted in a decrease in serum levels of the anti-cardiolipin antibodies, rise in platelet count, shortened aPTT and reduced rate of fetal loss. The anti-Id effect was associated with a rise in the number of IL-2 and interferon-gamma (IFN-gamma)-secreting cells (Th1) and reduction in IL-4- and IL-6-secreting cells (Th2). The beneficial effect of the anti-Id treatment in mice with experimental APS induced by active immunization with an idiotype further supports the idiotypic aetiology of experimental APS and points to the role of Th1 cytokines in suppression of its manifestations.