Chronic arthritis associated with the presence of intrasynovial rubella virus

Rubella Seroprevalence Boost in the Pediatric and Adolescent Population of Florence (Italy) as a Preventive Strategy for Congenital Rubella Syndrome (CRS)

BACKGROUND

Despite the availability of an effective vaccine since the 1970s, rubella disease and, importantly, congenital rubella syndrome (CRS) remain a public health concern. The aim of this study was to analyze the rubella seroprevalence in the children population of the province of Florence and compare the obtained results to a previous survey conducted in 2005-2006.

METHODS

A qualitative measurement of anti-rubella antibodies was performed on 165 sera using the enzyme-linked immunosorbent Assay (ELISA). The anamnestic and vaccination status was also collected.

RESULTS

Our study highlighted a very high rubella seroprevalence (85-100%) in our enrolled population. In the vaccinated group (153/165), 98.7% of them were positive to rubella antibodies.

CONCLUSIONS

Our study showed the highest seroprevalence rate reached in the province of Florence for rubella in the last 15 years, thanks to the several successful vaccination campaigns promoted in the Tuscany region. Our findings in pediatric and adolescent subjects are a key factor in preventing CRS in adult life, specifically in childbearing women. Thus, the set goal will be to keep the awareness about the vaccination for this preventable disease high.

Inflammatory arthritis and crystal arthropathy: Current concepts of skin and systemic manifestations

Systemic inflammatory disorders frequently involve the skin, and when cutaneous disease develops, such dermatologic manifestations may represent the initial sign of disease and may also provide valuable prognostic information about the underlying disorder. Familiarity with the various skin manifestations of systemic disease is therefore paramount and increases the likelihood of accurate diagnosis, which may facilitate the implementation of an appropriate treatment strategy. An improvement in quality of life and a reduction in the degree of morbidity may also be a realized benefit of accurate recognition of these skin signs. With this context in mind, this review highlights the salient clinical features and unique dermatologic manifestations of rheumatoid arthritis, adult-onset Still's disease, and the crystal arthropathy, gout.

Pathophysiology of articular chondrocalcinosis--role of ANKH

Calcium pyrophosphate (CPP) crystal deposition (CPPD) is associated with ageing and osteoarthritis, and with uncommon disorders such as hyperparathyroidism, hypomagnesemia, hemochromatosis and hypophosphatasia. Elevated levels of synovial fluid pyrophosphate promote CPP crystal formation. This extracellular pyrophosphate originates either from the breakdown of nucleotide triphosphates by plasma-cell membrane glycoprotein 1 (PC-1) or from pyrophosphate transport by the transmembrane protein progressive ankylosis protein homolog (ANK). Although the etiology of apparent sporadic CPPD is not well-established, mutations in the ANK human gene (ANKH) have been shown to cause familial CPPD. In this Review, the key regulators of pyrophosphate metabolism and factors that lead to high extracellular pyrophosphate levels are described. Particular emphasis is placed on the mechanisms by which mutations in ANKH cause CPPD and the clinical phenotype of these mutations is discussed. Cartilage factors predisposing to CPPD and CPP-crystal-induced inflammation and current treatment options for the management of CPPD are also described.

Mapping of genetic determinants of rubella virus associated with growth in joint tissue

Rubella virus (RV) strains vary in their abilities to replicate and persist in cell cultures derived from human joint tissue (synovial cells [SC]), and this arthrotropism appears to be linked to their association with joint symptoms in vivo. In order to map the genetic determinants of arthrotropism, an infectious clone of the Cendehill vaccine strain of RV was constructed, as well as two chimeric clones containing cDNAs from both Cendehill and Therien (wild-type) strains. Replacement of the entire structural gene region of Therien in the infectious clone pROBO302 with the corresponding region of Cendehill did not affect growth in SC. A further observation that Cendehill bound equally well to SC and the permissive Vero cell line indicated that restriction was not at the level of receptor binding, a function of the envelope proteins. Mutations that affected growth in joint cells were mapped to two locations in the nonstructural gene region. The first of these (nucleotides 2803 and 6416) resulted in a 10-fold decrease in yield of progeny virus from SC. This region contained five mutations, at nucleotides 2829, 3060, 3164, and 3528 (near the carboxy terminus of P150 where the protease domain is located) and at nucleotide 4350 in p90. Further substitution of the sequence representing nucleotides 1 to 2803 to give a complete Cendehill infectious clone restricted growth in SC by a further 100-fold to less than 10 PFU/ml. This region contains three mutations, at nucleotides 34, 37, and 55, within the 5' stem-loop structure. In conclusion, the Cendehill-specific mutations believed to be determinants of joint cell growth are located in two regions, the 5' nontranslated region and in a sequence that encodes the carboxy-terminal region of p150 extending into the helicase domain of p90.

Viruses and childhood arthritis

The role of viral infections in the aetiology of acute and chronic arthritides of childhood is incompletely understood. The fact that some viruses cause acute arthritis is certain, although in most instances of presumed viral arthritis no agent is identified. The associations of viruses with diseases such as juvenile chronic arthritis (JCA) are limited, and have been difficult to prove with certainty. Rubella, parvovirus B19 and influenza AH2N2 have been shown by culture, serology or epidemiology to be related to at least some cases of JCA in some studies, but not in others. A rationale for pursuing investigations of viral aetiology of chronic arthritis is discussed, and a strategy involving early disease detection and close collaboration between clinicians and scientists is proposed.

Viruses: immunosuppressive effects

Many virus infections in man and other species are accompanied by immunosuppression. This is clearly important in terms of the susceptibility of the host to secondary infections. The immunosuppression may also aid and abet the growth and persistence of viruses. An unresolved issue is the extent to which the extent of this immunosuppression is determined by the virulence of the infecting virus or resistance factors in the host, and particularly by factors that are genetically determined. The mechanisms of viral immunosuppression are indirect and direct. Indirect mechanisms such as interferon production and suppressor cells induced by infection undoubtedly contribute to viral immunosuppression in experimental models of virus infection. In man the direct inactivation of immunologically responsive lymphocytes seems to be the most important mechanism. Moreover, the persistence of viruses in human lymphocytes is being increasingly recognized.

Juvenile rheumatoid arthritis in Rochester, Minnesota 1960-1993. Is the epidemiology changing?

OBJECTIVE

To examine trends in the incidence and prevalence of juvenile rheumatoid arthritis (JRA) in Rochester, Minnesota, over 33 years.

METHODS

The diagnostic retrieval system of the Rochester Epidemiology Project was utilized to screen medical records of all Rochester residents with any potential diagnoses of JRA from 1978 to 1993 (based on the American College of Rheumatology 1977 revised criteria). In addition, all cases of JRA from our previously identified cohort from 1960-1979 were verified, and the 2 data sets were combined, resulting in an incidence cohort spanning 33 years (1960-1993).

RESULTS

Of the 1,240 medical records screened, we identified 65 cases of JRA diagnosed between 1960 and 1993 (48 females, 17 males). The average followup for cases was 12.7 years (range 0-34 years) for a total of 833 person-years of observation. A bimodal distribution of age at diagnosis was observed, with peaks between 0 and 4 years and 9 and 15 years. Seventy-two percent of patients had pauciarticular-onset, 17% had polyarticular-onset, and 11% had systemic-onset disease. Progression of pauciarticular to polyarticular disease occurred in 11% of the cases. The overall age- and sex-adjusted incidence rate was 11.7 per 100,000 population (95% confidence intervals 8.7, 14.8). The incidence rate per 100,000 population was 15.0, 14.1, and 7.8 for the time periods 1960-1969, 1970-1979, and 1980-1993, respectively (P = 0.024). A 3-year, centered, moving average, which was used to display time trends in incidence, suggested a cyclical pattern, with incidence peaks in 1967, 1975, and 1987.

CONCLUSION

An overall decrease in the incidence rate over the last decade was observed, most marked in the pauciarticular- and systemic-onset subtypes. This decrease, along with the observed cyclical pattern, suggest that environmental factors may influence disease frequency.

Persistence of alphaviruses in vertebrate hosts

Alphaviruses are a group of arthropod-borne, positive-strand RNA viruses that cause acute encephalitis or arthritis. These viruses were previously thought to cause only acute infections in vertebrates, but recent evidence suggests that host immunological and tissue-specific factors may act together to promote the persistence of alphavirus genomes in vivo.

Detection of rubella virus-specific immunoglobulin G (IgG), IgM, and IgA antibodies by immunoblot assays

Immunoblot (IB) assays were developed for detection of rubella virus (RV)-specific immunoglobulin G (IgG), IgM, and IgA antibodies in human serum following natural infection or immunization. IB assays performed under nonreducing conditions were compared with those performed under reducing conditions and with immunoprecipitation assays. Significant loss of antigenicity (greater than 90%) of RV E1 and E2 proteins was observed when IB assays were performed in the presence of 2-mercaptoethanol as compared with assays under nonreducing conditions. In contrast, the antigenicity of RV capsid protein was not influenced by reducing agents. Sensitivity of IB for RV-specific IgG antibodies was determined to be 0.01 IU/ml under nonreducing conditions. In the determination of RV-specific IgM and IgA antibodies by IB, pretreatment of serum with protein G to remove competing high-affinity RV-specific IgG or rheumatoid factor significantly improved assay sensitivity. IB assays were observed to be superior to immunoprecipitation assays in their ability to better define the specificities of RV-specific antibodies and to detect antibodies of all immunoglobulin classes. However, the conformational sensitivity of RV protein antigenicity should be an important consideration in the interpretation of RV-specific antibodies by IB assays.

Adult-onset Still's disease

Adult onset Still's disease seems to be the adult form of Still's disease in children. The key symptoms of the disease are high spiking fever, arthritis and a macular or maculopapular, salmon-pink evanescent rash, almost always accompanied by neutrophilic leukocytosis and frequently by sore throat, intense myalgias, lymphadenopathy, splenomegaly and signs of serositis. Tests for IgM rheumatoid factor and antinuclear antibody are characteristically negative. With respect to haematologic abnormalities, the disease may give rise to several problems. First, there is a neutrophilic leukocytosis, which currently is unexplained, and often a normocytic normochromic anaemia, that may be profound. The anaemia has the characteristics of anaemia of chronic inflammatory disease. Both abnormalities disappear after effective treatment of the disease or at spontaneous remission. Secondly, there might be a problem to differentiate AOSD from malignant haematological disorders, including malignant lymphoma and leukaemia, especially when the picture is dominated by lymphadenopathy, splenomegaly, fever and leukocytosis. Although in rare cases the differential diagnosis is extremely difficult, diagnosis can mostly be made or excluded by peripheral blood smear staining, bone marrow biopsies and occasionally lymph node biopsy. Finally, like the juvenile counterpart, AOSD is occasionally complicated by sometimes life-threatening diffuse intravascular coagulation. Factors that might be important in the development of this complication include severe disease activity, liver abnormalities and particular drugs including salicylates, other NSAIDs and some slow-acting antirheumatic drugs. Prompt therapy, including withdrawal of the drug, corticosteroids and sometimes anticoagulant therapy have been successfully applied to most patients.

The role of infections in the rheumatic diseases: molecular mimicry between bacterial and human stress proteins?

Infections can cause or exacerbate the rheumatic diseases in several ways, including immune cross-reactivity between bacterial heat shock proteins and similar proteins in normal human tissues. This may lead to autoimmunity in rheumatoid arthritis and systemic lupus. In addition, increased activation of the gene regulating the synthesis of a heat shock protein has been found in scleroderma fibroblasts. As an infection-induced model for other rheumatic diseases, rheumatic fever (RF), with its well-established link to prior group A streptococcal infection, will be revisited. The lessons learned from RF and other rheumatic diseases directly linked to infection will be applied to ankylosing spondylitis, rheumatoid arthritis, Sjogren's syndrome and polymyositis, for which a mounting body of circumstantial evidence suggests a probable infectious cause. The interplay of genetic susceptibility and infection with particular organisms and the implications of this new information for present and future therapy of the rheumatic diseases will also be presented.

Antibodies to Epstein-Barr viral antigens in familial rheumatoid arthritis

Serum antibodies to Epstein-Barr virus (EBV) were measured in members of twenty-nine families in which two or more first degree relatives had rheumatoid arthritis (RA). These patients were assessed clinically for activity of disease and their treatment recorded. A higher proportion of seropositive individuals was found among patients and affected kindred than among the non-affected groups. Antibody titres to Viral Capsid Antigen (VCA) tended to be higher in patients and affected kindred. In those individuals in whom antibody to Early Antigen (EA) was present there was a lower titre of antibody to Epstein-Barr Nuclear Antigen (ENBA). The results suggest that an immunoregulatory defect may exist in some patients with RA which allows for enhanced expression of EBV.

Reaction of rheumatoid factors with IgG3 monoclonal anti-Rh(D) antibodies: more frequent reactivity to a monoclonal antibody of the Gm allotype G3m(5) in rheumatoid patients negative for G3m(5)

Human monoclonal anti-Rh(D) antibodies of known IgG isotype and Gm allotype were bound to erythrocytes and then used as the target IgG antigens for rheumatoid factors (RFs) in a direct haemagglutination test. When serum samples from patients with rheumatoid arthritis (RA) were tested for RF specificity towards these IgG monoclonal anti-D antibodies the incidence and titre of reactivity towards an IgG3 monoclonal anti-D antibody was considerably greater than for a polyclonal anti-D antibody of the same Gm allotype, G3m(5). This difference was not explained by the amount of each anti-D antibody which bound to erythrocytes. Furthermore, when patients with RA were divided into groups according to their Gm phenotype, sera from a greater proportion of patients negative for the phenotype G3m(5) reacted to the G3m(5) monoclonal anti-D antibodies than sera from those patients positive for this allotype. Analysis of RF reactivities towards two IgG3 and three IgG1 monoclonal anti-D antibodies, each with different Gm allotypic epitopes, indicated, however, that individual serum samples contained RFs with a spectrum of specificities; some sera appeared to react to a single set of Gm alleles, whereas others also reacted to isotypic or iso-allotypic epitopes, or both. Our data suggest that RFs with specificity for Gm allotypes do not arise in patients who carry that particular allotype owing to tolerance induced in fetal-neonatal life. Conversely, RFs with apparent specificity for a Gm allotype formed in patients negative for that allotype may be reacting to a closely related but different epitope. Final proof requires precise specificities for each RF formed, and IgG3 monoclonal anti-D antibodies would be useful reagents for this purpose.

Adult onset Still's disease and viral infections

Several micro-organisms, especially viruses, have been associated with juvenile and adult onset Still's disease. In the present study a search for probable triggering viral infections in five consecutive patients with early, active adult onset Still's disease has been made. In one patient echovirus 7 was identified as a probable triggering agent. Evidence of infection with this virus was acquired by virus cultures and serological tests. In two patients the illness was probably initiated by a rubella reinfection. Both had initially high stable monospecific IgG antibody titres but no IgM antibodies to this virus. In the remaining two cases no particular triggering viral infection could be designated. Evidence of a viral infection was thus found in three of these five patients. Adult onset Still's disease may represent a reaction pattern to certain infections.

Generation of defective-interfering particles by rubella virus in Vero cells

The generation of defective-interfering (DI) particles by rubella virus during serial undiluted passage and persistent infection in Vero cells was studied. A series of 24 serial undiluted passages was initiated with plaque-purified virus. The virus titer remained relatively constant through the first nine passages, after which it declined, reaching a low level of 20-fold less than the originating stock by passage 15. In subsequent passages, the titer cycled. Intracellular DI RNAs were first detectable at passage 4, at which time DI RNAs of 7500 and 1400 nucleotides in length were observable. Thus, the rate of which DI RNAs were generated by rubella virus during serial undiluted passage was similar to the rate of DI generation by other enveloped RNA viruses during serial undiluted passage. The longer rubella DI RNA was present in all passages subsequent to passage 4, while the 1400-nucleotide DI RNA was replaced by a DI RNA of 800 nucleotides in length by passage 15. Subsequent to passage 7, the relative amount of genomic RNA declined dramatically and the DI RNAs became the predominant intracellular virus-specific RNA species. Negative-polarity RNA species corresponding to the 7500- and 800-nucleotide DI RNA species were identified. The 7500- and 1400-nucleotide DI RNA species were encapsidated into virus particles while the presence of the 800-nucleotide DI RNA species in virus particles could not be detected. Interestingly, the rubella virus subgenomic RNA was present in virus particles in preparations containing DI RNAs. A persistent infection was initiated by subculturing the surviving cells from a high multiplicity of infection with plaque-purified virus. Intracellular DI RNAs were first detectable at Day 19 after initiation of persistence and became significant by Day 26. The amount of genomic RNA began to decrease at Day 47 and was undetectable after Day 68. Through Day 54, there were several DI RNA species present, but at later times, one of these species became predominant. Thus, DI particles were generated during persistent infection, but their presence was not necessary for initiation of persistence.

Human parvovirus B19 DNA in synovial fluid

We describe a 33-year-old woman with a serologically proven human parvovirus B19 infection, who developed synovitis. Using a dot-blot hybridization technique, we detected B19 DNA in her synovial fluid. To our knowledge, this is the first report of the isolation of B19 from synovial fluid.

An investigation of the action of disease modifying antirheumatic drugs on the rheumatoid synovial membrane: reduction in T lymphocyte subpopulations and HLA-DP and DQ antigen expression after gold or penicillamine therapy

Synovial needle biopsy specimens from the knee joints of seven patients with rheumatoid arthritis (RA) were examined immunohistochemically before and after six months' treatment with either gold or penicillamine (disease modifying drugs, DMDs). There were significant reductions in the numbers of infiltrating T lymphocytes and a disproportionate fall in the numbers of lymphocytes of the helper/inducer subset when compared with those of the suppressor/cytotoxic subset. This resulted in a fall in the ratio of helper/inducer to suppressor/cytotoxic cells. The immunohistological changes correlated with improvements in erythrocyte sedimentation rate (ESR), serum immunoglobulins, visual analogue pain assessment, grip strength, and Ritchie articular index. A second group of nine patients with RA, already well established on DMD therapy, did not show similar changes after the six month period. The HLA class II antigens DR, DQ, and DP were widely expressed on lymphocytes, macrophages, and synovial lining cells of a group of patients with RA who had never received disease modifying drug therapy. After treatment there was a significant reduction in the expression of HLA-DP and DQ antigens.

Infection and arthritis

The categorization in four classes of association between infection and arthritis (namely infective, post-infective, reactive and idiopathic) seems nowadays to be inadequate to cover the extensive field of interactions between infectious agents and host response resulting in arthritis. This paper is a synthetic review of the subject with particular reference to pathogenetic mechanisms in children. An effort has been accomplished, on the basis of the most recent literature, to define the respective roles of the microbial aggression and the host response in a number of conditions: septic arthritis, viral arthritides, Lyme arthritis, rheumatic fever, Reiter's syndrome, ankylosing spondylitis and rheumatoid arthritis.

Synthesis of antibodies, including antiviral antibodies, in the knee joints of patients with arthritis

Serum and synovial fluids from 16 patients with seronegative arthritis and eight with rheumatoid arthritis were studied for immunoglobulin levels and for antibody levels to five viruses. When allowances were made for the distribution of immunoglobulins between serum and synovial fluid there was evidence that in several patients antibody to one or more viruses was synthesised locally in the joint. IgG and especially IgM were present in greatly increased amounts in arthritic joints compared with normal joints. On the basis of serum/synovial fluid ratios inflammation and local immunoglobulin synthesis are discussed as possible causes. These results are compared with antiviral antibody and immunoglobulin ratios observed in the serum and cerebrospinal fluid of patients with multiple sclerosis.

Persistent rubella virus infection associated with chronic arthritis in children

We isolated rubella virus from lymphoreticular cells in 7 of 19 children with chronic rheumatic disease, including patients with systemic-onset juvenile rheumatoid arthritis (Still's disease) (1 of 5), polyarticular juvenile rheumatoid arthritis (2 of 2), pauciarticular juvenile rheumatoid arthritis (2 of 6), and seronegative spondyloarthritis (2 of 6). In contrast, rubella virus was not isolated from the control group, which included eight normal subjects and eight patients with other connective tissue diseases or traumatic joint effusion. In most members of the study group, mononuclear cells from both synovial fluid and peripheral blood were examined. Rubella virus was isolated from both cell populations in three patients, from only peripheral blood in one, and from only synovial fluid in two. In the children with systemic-onset juvenile rheumatoid arthritis, only peripheral blood was examined, and of the five samples analyzed, one was shown to have rubella virus. Virus was isolated on more than one occasion from four of seven persons. Persistence of rubella virus in lymphoreticular cells in 35 per cent of these cases of juvenile arthritis supports the view that the virus may be an etiologic agent in chronic human joint disease, but further work will be required to support this suggestion.

Sequential studies on synovial lymphocyte stimulation by rubella antigen, and rubella virus isolation in an adult with persistent arthritis

The response of synovial lymphocytes from a 65-year-old lady with persistent polyarthritis, to rubella antigen and a number of other microbial agents was studied over a period of 11 months by [3H]thymidine incorporation. The results were correlated with the ability to isolate rubella virus from both peripheral blood and synovial fluid during the same period. The patient showed initially a maximal stimulation index to rubella antigen assayed on five occasions over a five-month period. Rubella virus was detected in both peripheral blood and synovial fluid samples on three occasions during this period. Five months later the lymphoproliferative response of her synovial lymphocytes to rubella antigen had dropped to low levels, and virus could no longer be isolated from synovial exudates. At this time the patient's arthritis had become much less active, indicating that a good correlation existed between the presence of rubella virus, local lymphocyte sensitisation, and the inflammatory reaction.

Human parvovirus-associated arthritis: a clinical and laboratory description

An outbreak of human parvovirus-associated erythema infectiosum in the Grampian region has enabled us to study the association between this small DNA virus and arthritis. This report deals with 42 patients with joint pains, in whom serological evidence of recent human parvovirus (HPV) infection was obtained. The clinical description of the disorder is based on 17 of the patients who were seen in the clinic and a further 13 patients for whom information was obtained by questionnaire. Detailed clinical features were not available for the remaining 12 patients. A rash was present in all 3 affected children but only 13 of the 27 adults. Viral prodromata were present in only 13 adults. 7 adults had neither rash nor viral prodromata. The arthritis was more common in adults than children and affected principally the female sex. In adults the arthritis was symmetrical, affecting the small joints of the hands, wrists, and knees most commonly. In all cases it was self-limiting, usually resolving within 4 weeks, although 1 adult had more persistent disease lasting almost 6 months. The 3 children reported in detail had less symmetrical and more persistent disease, which in 1 case has lasted over 7 months.

Limb pain in childhood

As the presenting complaint in 7 per cent of pediatrician visits, pain in the limbs is a common problem in childhood. It is important that the diagnosis be made expeditiously. The authors review the possible organic cause of limb pain, as well as limb pain from conversion reactions and from growing pains, giving special attention to the differential diagnosis so that appropriate treatment for the pain can be initiated.

Interferon triggers experimental synovitis and may potentiate auto-immune disease in humans

From these data it appears that IFN is capable of stimulating prostaglandin E and hyaluronic acid production by human synovial fibroblasts in vitro and of initiating an inflammatory reaction in animal joints. In chronic arthritis its production may result from persisting viral or other antigenic stimulation. IFN may enhance the immune response and mediate the inflammatory process in the joint. Its role in the pathogenesis of rheumatic and various other autoimmune diseases is undergoing further study.