Vaccination with a T-cell-priming Gag peptide of caprine arthritis encephalitis virus enhances virus replication transiently in vivo

CD4+ T cells are involved in several immune response pathways used to control viral infections. In this study, a group of genetically defined goats was immunized with a synthetic peptide known to encompass an immunodominant helper T-cell epitope of caprine arthritis encephalitis virus (CAEV). Fifty-five days after challenge with the molecularly cloned CAEV strain CO, the vaccinated animals had a higher proviral load than the controls. The measurement of gamma interferon and interleukin-4 gene expression showed that these cytokines were reliable markers of an ongoing immune response but their balance did not account for more or less efficient control of CAEV replication. In contrast, granulocyte-macrophage colony-stimulating factor appeared to be a key cytokine that might support virus replication in the early phase of infection. The observation of a potential T-cell-mediated enhancement of virus replication supports other recent findings showing that lentivirus-specific T cells can be detrimental to the host, suggesting caution in designing vaccine candidates.

Demonstration of coinfection with and recombination by caprine arthritis-encephalitis virus and maedi-visna virus in naturally infected goats

Recombination of different strains and subtypes is a hallmark of lentivirus infections, particularly for human immunodeficiency virus, and contributes significantly to viral diversity and evolution both within individual hosts and within populations. Recombinant viruses are generated in individuals coinfected or superinfected with more than one lentiviral strain or subtype. This, however, has never been described in vivo for the prototype lentivirus maedi-visna virus of sheep and its closely related caprine counterpart, the caprine arthritis-encephalitis virus. Cross-species infections occur in animals living under natural conditions, which suggests that dual infections with small-ruminant lentiviruses (SRLVs) are possible. In this paper we describe the first documented case of coinfection and viral recombination in two naturally infected goats. DNA fragments encompassing a variable region of the envelope glycoprotein were obtained from these two animals by end-limiting dilution PCR of peripheral blood mononuclear cells or infected cocultures. Genetic analyses, including nucleotide sequencing and heteroduplex mobility assays, showed that these goats harbored two distinct populations of SRLVs. Phylogenetic analysis permitted us to assign these sequences to the maedi-visna virus group (SRLV group A) or the caprine arthritis-encephalitis virus group (SRLV group B). SimPlot analysis showed clear evidence of A/B recombination within the env gene segment of a virus detected in one of the two goats. This case provides conclusive evidence that coinfection by different strains of SRLVs of groups A and B can indeed occur and that these viruses actually recombine in vivo.

Caprine Arthritis Encephalitis Complex

The caprine arthritis encephalitis virus (CAEV) is a lentivirus that persistently infects goats and sheep. The finding thatCAEV and Maedi-Visna viruses frequently cross the species barrier between goats and sheep, and vice versa, has changedour view of the epidemiology of these viruses that are now referred to assmall ruminant lentiviruses (SRLV).CAEV is transmitted from infected mothers to their offspring, mainly via ingestion of infected colostrum and milk. Thispermits the implementation of control measures based on the segregation ofnewborn kids immediately after birth thatsuccessfully cut the seroprevalence in infected flocks, eliminating CAEV induced clinical disease. CAEV induces overtpathology in about one third of the infected animals. The frequency of affected animals varies in different goat families,pointing to an important genetic component in this disease. The principal manifestations areencephalitis and interstitialpneumonia in young animals,whereas arthritis and mastitispredominate in adult goats. The immunopathologicalmechanisms leading to diseaseare to date unclear and involve the principal components ofthe immune system, i.e., theprofessional antigen presenting cells, which are the principal target of CAEV, and whose activity, e.g., cytokine production,is modulated by the infection, and the B- and T-cell immune responses that are alsomanipulated by the virus.In vivo,infected animals usually have low viral loads, indicating that virus replication istightly restricted by mechanisms thatremain unclear. Finally, the complex biology of SRLV makes them a great challenge for diagnostic laboratories.In this brief review, the literature pertinent toall these aspects is summarized and discussed.

Experimental arthritis: effect on growth parameters and total skeletal calcium

Aim of the study was to investigate the possible mechanisms leading to stunted growth and osteoporosis in experimental arthritis. Fourty-two female rats of 7-8 weeks of age were randomly assigned to three groups of 14 animals each: (a) controls; (b) adjuvant-inoculated (AA); and (c) adjuvant-inoculated rats receiving 10 mg cyclosporin A (CsA) orally for 30 days. Biological parameters studied were: hindpaw swelling; vertebral length progression expressed as Delta increments between days 1 and 30 as a parameter of skeletal growth, and estimation of total skeletal mineral content by dual energy X-ray absorptiometry (n=10 each group) on day 30. Endocrine parameters measured were pulsatile release of growth hormone (rGH) on day 30 following jugular cannulation and measurement of insulin-like growth factor (IGF-1) in pooled plasma from rGH profiles. Results can be summarized as follows: Untreated AA rats exhibited local signs of inflammation in comparison with controls (hindpaw diameter 8.1-8.9 mm vs. 5.3-5.6 mm in controls). Treatment with CsA normalized this parameter (4.9-5.6 mm). Vertebral growth was significantly retarded in AA rats in comparison with controls (214+/-32 vs. 473+/-33 microm; p<0.001). Administration of CsA normalized vertebral size increment with a clear tendency to overgrowth (523+/-43 microm, n.s.). There was also a marked reduction in total skeletal mineral content in diseased (AA) rats as compared to controls (5.8+/-0.1 vs. 7.5+/-0.1g [OH-apatite]; p<0.001), and a moderate but significant increment above controls in the group receiving CsA (8.0+/-0.1 vs. 7.5+/-0.1g [OH-appatite]; p<0.04). Integrated rGH profiles exhibited a significant fall in arthritic rats and were completely restored to normal under CsA treatment. A trend toward higher rGH values was observed in the latter group (2908+/-554 in AA vs. 8317+/-1492 ng/ml/240 min in controls; p<0.001, and 10940+/-222 ng/ml/240 min, n.s. in the CsA group). There was a good correlation between skeletal growth and rGH pulsatility (r=0.81; p<0.001). IGF-1 followed a similar pattern (630+/-44 in AA vs. 752+/-30 ng/ml in controls; p<0.04, and 769+/-59 ng/ml in the CsA group, n.s. vs. controls). Thus, a clear tendency to skeletal overgrowth following treatment was observed in agreement with the hormonal data. It can therefore be concluded that, in experimental arthritis, attenuated GH-spiking and reduced circulating IGF-1 appear to be causally related to growth retardation, probably mimicking signs and symptoms observed in juvenile arthritis. Therapy with CsA is followed by normalization of hormonal and biological parameters accompanied by a catch up phenomenon in skeletal growth which is also observed clinically in juvenile arthritis. Generalized osteopenia is a prominent feature seemingly connected with the growth abnormalities as they parallel each other during the evolution of the disease and respond equally to therapy.

Soluble tumour necrosis factor receptors sTNFR1 and sTNFR2 are produced at sites of inflammation and are markers of arthritis activity in Behçet's disease

OBJECTIVE: We analysed the production of soluble tumour necrosis factor receptors sTNFR1 and sTNFR2 at sites of inflammation and measured their plasma concentrations to evaluate them as biological markers of disease activity. METHODS: Plasma samples of 35 patients with Behçet's disease (BD) were collected prospectively at monthly intervals and grouped for inactive disease, active BD without arthritis, and active BD with arthritis. sTNFR1 and sTNFR2 concentrations were measured using immunoassays and compared with other biological disease activity parameters. Plasma sTNFR levels were compared to synovial fluid (SF) levels in seven patients. Sixteen tissue samples of mucocutaneous lesions were stained for TNFR2 expression by immunohistochemistry. RESULTS: sTNFR1 and sTNFR2 were found at increased plasma concentrations in active BD, with the highest concentration in active BD with arthritis (p<0.001). Concentrations of both sTNFRs were at least three times higher in SF of arthritic joints than in the corresponding plasma samples (p = 0.025). A change of more than 1 ng/mL of sTNFR2 plasma concentrations correlated with a concordant change in arthritic activity (96% confidence interval). Sensitivity to change was superior to that of sTNFR1, and other biological disease activity parameters such as erythrocyte sedimentation rate (ESR), immunoglobulin (Ig)G, IgA, and interleukin (IL)-10 plasma concentrations. A strong staining for TNFR2 was found in mucocutaneous lesions, where mast cells were identified as the major source for this receptor. CONCLUSIONS: This longitudinal study demonstrates that sTNFR2 plasma concentrations are closely linked with active BD, and especially with arthritis. Taken together with the expression of TNFR molecules in mast cells of mucocutaneous lesions, our results indicate a fundamental role for the TNF/TNFR pathway in BD.

Alopecia areata universalis elicited during treatment with adalimumab

Adalimumab is a fully humanized recombinant anti-tumour-necrosis-factor (TNF-alpha) monoclonal antibody which has been approved for rheumatoid arthritis, active ankylosing spondylitis, psoriatic arthritis and Crohn's disease. We report a case of alopecia areata (AA) universalis occurring 6 months after administration of adalimumab monotherapy in a patient with a long-standing history of psoriatic arthritis and psoriasis. The diagnosis was confirmed by a scalp biopsy which showed a peribulbar infiltrate of both CD4+ and CD8+ T cells, CD1a+ dendritic cells as well as CD68+ and CD163+ macrophages. In addition, immunofluorescence staining for TNF-alpha was found in the mononuclear cell infiltrate. This case suggests a complex role of TNF-alpha in the induction of AA.

[Diagnostics of autoimmune diseases]

Autoantibodies play a key role in diagnostic laboratories as markers of autoimmune diseases. In addition to their role as markers they mediate diverse effects in vivo. Autoantibodies with protective effect have been described. Natural protective IgM autoantibodies against tumour-antigens of malignant cells or their precursors may contribute to increased survival rates of carcinoma patients. In a mouse model of systemic lupus erythematosus it has been shown that anti-dsDNA IgM autoantibodies protect from glomerular damage. In contrast, a direct pathogenic role of autoantibodies has been well established e.g. in myasthenia gravis or in Goodpasture syndrome. Similarly autoantibodies against SSA Ro52 are detrimental in neonatal lupus erythematosus with congenital heart block. Moreover, putatively protective autoantibodies may become pathogenic during the course of the disease such as the onconeuronal autoantibodies whose pathogenicity depends on their compartmentalisation. In patients with paraneoplastic syndromes tumour cells express proteins that are also naturally present in the brain. Anti-tumour autoantibodies which temporarily suppress tumour growth can provoke an autoimmune attack on neurons once having crossed the blood-brain barrier and cause specific neurological symptoms. Only a restricted number of autoantibodies are useful follow-up markers for the effectiveness of treatment in autoimmune diseases. Certain autoantibodies hold prognostic value and appear years or even decades before the diagnosis of disease such as the antimitochondrial antibodies in primary biliary cirrhosis or anti-citrullinated protein (CCP)-antibodies in rheumatoid arthritis. It is crucial to know whether the autoantibodies in question recognise linear or conformational epitopes in order to choose the appropriate detection methods. Indirect immunofluorescence microscopy remains a very useful tool for confirmation of results of commercially available immunoassays and for detection of special and rare autoantibodies that otherwise often remain undetected. Standardisation of autoimmune diagnostics is still underway and requires joint efforts by laboratories, clinicians and industry.

Limited value of cyclosporine A for the treatment of patients with uveitis associated with juvenile idiopathic arthritis

AIMS: Juvenile idiopathic arthritis (JIA) is often associated with severe chronic anterior uveitis (CAU), and immunosuppressive therapy may be required. In this study, the value of cyclosporine A (CsA) as monotherapy or as combination therapy for treating uveitis was studied in a large cohort of JIA children. METHODS: Multicentre retrospective study including 82 JIA children (girls n=60) suffering from unilateral or bilateral (n=55) CAU. The indication for CsA was active uveitis, although patients were on topical or systemic corticosteroids, MTX, or other immunosuppressive drugs. RESULTS: Inactivity of uveitis during the entire treatment period (mean 3.9 years) was obtained with CsA monotherapy in 6 of 25 (24%) patients, but more often when CsA was combined with the immunosuppressives (35/72 patients; 48.6%, P=0.037), or MTX (18/37 patients, 48.6%, P=0.065), which had already been given. With CsA (mean dosage 2.9 mg/kg), systemic immunosuppressive drugs and steroids could be reduced by >or=50% (n=19) or topical steroids reduced to

Novel screening tools for latent tuberculosis: time to leave an old friend?

PURPOSE OF REVIEW: Therapeutic inhibition of tumour necrosis factor-alpha strongly increases the risk of reactivation in latent tuberculosis infection. Recent blood tests based on antigen-specific T cell response and measuring production of interferon-gamma, so called interferon-gamma release assays (IGRAs), are promising novel tools to identify infected patients. The performance of diagnostic testing for latent tuberculosis infection in patients with rheumatic diseases will be discussed. RECENT FINDINGS: In patients with rheumatoid arthritis, IGRAs are more sensitive and more specific than traditional tuberculin skin testing. They are unaffected by Bacillus-Calmette-Guérin vaccination and most nontuberculous mycobacteria. Most comparative studies show a better performance of the IGRAs than tuberculin skin testing in terms of a higher specificity. The rate of indeterminate results may be affected by glucocorticoids and the underlying disease but appears independent of disease-modifying antirheumatic drugs. Despite using identical Mycobacterium tuberculosis antigens, the two commercially available tests show differences in clinical performance. SUMMARY: The current information about the performance of the tuberculin skin testing and the IGRAs in the detection of latent tuberculosis infection in patients with rheumatic diseases strongly suggest a clinically relevant advantage of the IGRAs. Their use will help to reduce overuse and underuse of preventive treatment in tumour necrosis factor inhibition.

Measuring finger joint cartilage by ultrasound as a promising alternative to conventional radiograph imaging

OBJECTIVE: To evaluate the reliability and validity of a novel ultrasound (US) imaging method to measure metacarpophalangeal (MCP) and proximal interphalangeal (PIP) finger joint cartilage. METHODS: We examined 48 patients with rheumatoid arthritis (RA), 18 patients with osteoarthritis (OA), 24 patients with unclassified arthritis of the finger joints, and 34 healthy volunteers. The proximal cartilage layer of MCP and PIP joints for fingers 2-5 was bilaterally visualized from a posterior view, with joints in approximately 90 degrees flexion. Cartilage thickness was measured with integrated tools on static images. External validity was assessed by measuring radiologic joint space width (JSW) and a numeric joint space narrowing (JSN) score in patients with RA. RESULTS: Precise measurement was possible for 97.5% of MCP and 94.2% of PIP joints. Intraclass correlation coefficients for bilateral total joint US scores were 0.844 (95% confidence interval [95% CI] 0.648-0.935) for interobserver comparisons and 0.928 (95% CI 0.826-0.971) for intraobserver comparisons (using different US devices). The US score correlated with JSN for both hands (adjusted R(2) = 0.513, P < 0.001) and JSW of the same finger joints (adjusted R(2) = 0.635, P < 0.001). Reduced cartilage shown by US allowed discrimination of early symptomatic OA versus early RA and healthy joints. In patients with RA, US scores correlated with duration of treatment-resistant, progressive RA. CONCLUSION: The US method of direct visualization and quantification of cartilage in MCP and PIP joints is objective, reliable, valid, and can be useful for diagnostic purposes in patients with arthritis.

Management of RA medications in pregnant patients

A desire for children or the presence of pregnancy limits the drug therapy options for a woman with rheumatoid arthritis. Combination therapies that include methotrexate or new drugs that have not been studied or used in pregnant patients must be excluded, even though they might be highly efficacious. With few exceptions, the reason for this exclusion is not the proven teratogenicity of the drugs, but the absence of proven safety for the fetus. Whereas methotrexate, leflunomide, abatacept and rituximab must be withdrawn before a planned pregnancy, tumor necrosis factor inhibitors and bisphosphonates can be continued until conception. Antimalarial agents, sulfasalazine, azathioprine and ciclosporin are compatible with pregnancy, and so can be administered until birth. Corticosteroids and analgesics such as paracetamol (acetaminophen) can also be used throughout pregnancy. NSAIDs can be safely administered until gestational week 32. The most important consideration when managing rheumatoid arthritis medications during pregnancy is that therapy must be tailored for the individual patient according to disease activity.