Association of parvovirus B19 infection and Hashimoto's thyroiditis in children.

Hashimoto's thyroiditis is a common autoimmune disorder of the thyroid gland. It has been linked to infections with hepatitis C, EBV, HTLV-1, and Yersinia enterocolitica. As parvovirus B19 has been associated with a wide spectrum of autoimmune diseases, we investigated the potential role of B19 infection in inducing Hashimoto's thyroiditis. Serum samples derived from 73 children and adolescents with Hashimoto's thyroiditis and from 73 age-matched controls were included in the study. The mean age of disease manifestation was 10 y 7 mo. All samples were analyzed for the presence of viral DNA and for antibodies against VP1, VP2, and NS1 proteins. VP1- and VP2-specific antibodies were present in 38 patients (52%) and 43 controls (59%; N.S.). NS1-specific antibodies were detectable in 23 patients (32%) and 19 controls (26%; N.S.). Parvovirus B19 DNA was detectable in 9 patients (12%) and 2 controls (3%; p < 0.03), indicating recent B19-infection. A negative correlation between disease duration and the detection of viral DNA was seen. The mean disease duration in B19-DNA-positive patients was 6 mo, compared to 29 mo in the remainder (p < 0.01). There is strong evidence that acute parvovirus B19 infections are involved in the pathogenesis of some cases of Hashimoto's thyroiditis.

Different patterns of disease manifestations of parvovirus B19-associated reactive juvenile arthritis and the induction of antiphospholipid-antibodies.

Children with rheumatic oligo- and polyarthritis frequently establish persistent parvovirus B19 infections, which may be associated with the production of antiphospholipid antibodies. Reported in this paper are the data of five girls with polyarticular rheumatic diseases of different types and persistent parvovirus B19 infection associated in four cases with the presence of antibodies against phospholipids. Clinical parameters, virus load, and antiphospholipid-IgG levels were determined during an observation period up to 92 months. In two patients, erythema infectiosum preceded the development of arthritis and B19 viremia persisted. Two other girls showed antibodies against parvoviral structural proteins at time of the manifestation of the rheumatic disease. Subsequent samples also revealed persistent B19 infection. In the fifth patient, parvovirus B19-specific IgG antibodies were detected for the first time after 120 months of progressing disease at an age of 11 1/2 years. Five years later, quantitative polymerase chain reaction (PCR) revealed viral DNA. In a synovial tissue specimen subsequently obtained, parvovirus B19 structural proteins could be detected by immunohistochemistry. Three of five patients recovered completely without severe sequels. One patient is in remission under immunosuppressive therapy. The fifth patient suffers from progressive erosions despite intensive therapeutical efforts. In consequence, parvovirus B 19 should generally be taken into consideration as a trigger of various forms of juvenile arthritis and persistence of infection should be evaluated.

Human parvovirus B19 infection and antiphospholipid antibodies.

Erythema infectiosum is the main manifestation of human parvovirus B19 infections. Further B19-related diseases commonly associated with the acute infection are flue-like symptoms, transient aplastic crisis, transient arthralgias, leukopenia and thrombocytopenia, spontaneous abortion and hydrops fetalis in pregnant women. Hepatitis, myocarditis, meningitis, encephalitis as well as pure red cell anemia may occur occasionally. In addition parvovirus B19 infections have been frequently described as cause or trigger of various forms of autoimmune diseases affecting all blood cell lines, joints, connective tissue, uvea, large and small vessels. Molecular mimicry may be one major contribution to the appearance of autoimmune antibodies, f.e. antiphospholipid and antineutrophil cytoplasmic antibodies as well as antinuclear antigens. These mechanisms implicated in the pathogenesis of parvovirus B19 triggered autoimmune diseases, especially focused on the development of antiphospholipid antibodies will be discussed in this short review.

Intravenous immunoglobulin treatment of four patients with juvenile polyarticular arthritis associated with persistent parvovirus B19 infection and antiphospholipid antibodies.

Children with rheumatic oligoarthritis and polyarthritis frequently establish persistent parvovirus B19 infections that may be associated with the production of antiphospholipid antibodies (anti-PL IgG). In this study we analysed the influence of high-dose intravenous immunoglobulin (IVIG) therapy on virus load, on the level of anti-PL IgG and its potential capacity to improve the patients' clinical status. Four juvenile patients with long-lasting polyarticular rheumatic diseases and persistent parvovirus B19 infection, associated in three cases with the presence of antibodies against beta2-glycoprotein I (anti-beta2GPI IgG), were treated with two cycles of IVIG on five successive days (0.4 g/kg per day). Clinical parameters including scores of disease activity, virus load and anti-PL IgG levels were determined before, during and after treatment. Two patients showed a complete remission that has lasted 15 months. During that period they showed neither clinical nor laboratory signs of inflammation. Viral DNA was not detectable in serum, and a decrease in anti-beta2GPI IgG was observed. As assessed by the Childhood Health Assessment Questionnaire and the Health-related Quality of Life Questionnaire for Children, both patients were no longer restricted in their activities of daily living and no impact on the health-related quality of life was observed. In one patient the therapy failed: there was no improvement of symptoms and no decrease in virus load or inflammatory parameters. In the fourth patient, clinical and laboratory parameters did not improve despite a decrease in both viral load and anti-PL IgG. Our results show that the use of IVIG to treat parvovirus B19-triggered polyarticular rheumatic disease of childhood might offer an opportunity to improve this disabling condition.

Parvovirus B19 infection and autoimmune disease.

Human parvovirus B19 infections may cause a widespread benign and self-limiting disease in children and adults, known as erythema infectiosum or fifth disease. A variety of further manifestations are associated with the infection such as arthralgias, arthritis, leukopenia and thrombocytopenia, anemia and vasculitis, spontaneous abortion and hydrops fetalis in pregnant women. Both in children and adults parvovirus B19 infections have been frequently implicated as a cause or trigger of various forms of autoimmune diseases affecting joints, connective tissue and large and small vessels. In addition, autoimmune neutropenia, thrombocytopenia and hemolytic anemia are known as sequelae of B19 infection. The molecular basis of the autoimmune phenomena and resultant pathogenesis is unclear. The involvement of molecular mimicry between cellular and viral proteins, the induction of enhanced cytokine production via the viral transactivator protein NS1 and the phospholipase A2-like activity of the capsid protein VP1 may contribute to the induction of autoimmune reactions. All the known data and the potential mechanisms involved in the pathogenesis will be discussed in this review.

Antiphospholipid antibodies in pediatric and adult patients with rheumatic disease are associated with parvovirus B19 infection.

OBJECTIVE: To show a possible association between parvovirus B19 infection and the presence of antiphospholipid antibodies (aPL) in patients with rheumatic diseases. METHODS: Serum samples obtained from 88 children with various forms of juvenile rheumatic disease and from 40 adults with systemic lupus erythematosus, the antiphospholipid syndrome, or other rheumatic disease, who had previously been tested and shown to be positive for IgG aPL, were analyzed for the presence of B19 DNA, for antibodies against the B19 viral proteins VP1, VP2, and NS1, and for IgG aPL (anticardiolipin, anti-beta(2)-glycoprotein I, and antiphosphatidylserine). As controls, serum samples obtained from 135 children with noninflammatory bone diseases or growth retardation were also analyzed. RESULTS: Twenty-four (27%) of the 88 children with rheumatic diseases had detectable amounts of IgG aPL. Fourteen (58%) of these 24 IgG aPL-positive patients showed IgG against VP1/VP2 and viral genomes, indicating the presence of acute (2 patients) or persistent (12 patients) infection. Past parvovirus B19 infection was identified in 7 (29%) of 24 IgG aPL-positive children, as indicated by VP1/VP2-specific IgG in the absence of viral DNA. Three (12%) of 24 IgG aPL-positive children had not been infected with B19. Sixty-nine (51%) of 135 control children displayed VP1/VP2-specific IgG. Three (2%) of these 135 children were IgG aPL positive (2 children had past parvovirus B19 infection, and 1 was negative for parvovirus B19). Analysis of the parvovirus B19 status of 40 adult IgG aPL-positive patients showed that 33 (83%) were anti-IgG VP1/VP2-positive, and viral DNA was detected in 11 patients (28%). Ten of these 11 viremic patients were in the subgroup of 28 IgG aPL-positive SLE patients. CONCLUSION: Antiphospholipid antibodies are preferentially found in serum of children with juvenile idiopathic arthritis who have been previously infected with parvovirus B19 and have established, persistent infection. Adult patients with IgG aPL positivity have a high incidence of persistent parvovirus B19 infection. We conclude that parvovirus B19 might be directly involved in the elicitation of autoimmune reactions partly mediated by aPL.

Frequent infection with a viral pathogen, parvovirus B19, in rheumatic diseases of childhood.

OBJECTIVE: To find further evidence of the association of parvovirus B19 infection with juvenile rheumatic diseases, and to get new insights into the immunopathogenesis of these diseases. METHODS: Paired serum and synovial fluid samples from 74 children with rheumatic disease were analyzed with respect to their content of viral DNA and antibodies directed against the B19 viral proteins VP1, VP2, and NS1. Control sera from 124 children with noninflammatory bone diseases or growth retardation were also analyzed. The sequence of the viral DNA, amplified by polymerase chain reaction (PCR), was determined. IgG-complexed virus was isolated from sera and synovial fluid by adsorption to protein A beads. The amount of free virus versus immunocomplexed virus particles was determined by quantification of the viral genomes by quantitative PCR. RESULTS: Twenty-six of the 74 patients (35%) had detectable amounts of parvovirus B19 DNA in the serum (n = 22 [30%]) and/or the synovial fluid (n = 16 [22%]), whereas only 9 of the 124 control sera (7%) were positive for the viral DNA (P < 0.0001). Forty-six patients (62%) had serum IgG against the structural proteins, indicating past infection with B19. NS1-specific antibodies were detected in sera from 29 patients (39%) and 27 controls (22%) (P < 0.001). In addition, 3 patients (4%) showed VP2-specific IgM. In 15 patients, viral DNA could be repeatedly detected in followup samples of serum and synovial fluid. Sequencing revealed low-degree nucleotide variations that are in the range of genotype 1 of parvovirus B19. Immunocomplexed virus was present in varying amounts, both in the sera and in the synovial fluid samples. CONCLUSION: Parvovirus B19 is frequently found in serum or synovial fluid of children with rheumatism. The rate of persistent B19 infection in these patients is significantly higher than in age-matched controls.

Chronic human parvovirus B19 infection in rheumatic disease of childhood and adolescence.

Parvovirus B19 causes erythema infectiosum in children, but the virus is associated with an increasing range of different diseases. About 20% of infections are associated with delayed virus elimination and viremia persisting over several months or years. These persistent B19-infections are characterised by the presence of IgG against the non-structural protein NS1. This study aimed to find further evidence for an association of parvovirus B19 persistence with VP1/2- and NS1-specific IgG-antibodies in children suffering from rheumatic diseases of childhood. Forty-eight children and adolescents with joint complaints lasting longer than 1 year including patients with juvenile systemic sclerosis and juvenile dermatomyositis showed antibodies against the viral NS1-protein. Laboratory markers of inflammation, humoral immune response against parvovirus B19 proteins and the presence of viral genomes in patients' sera as well as in 124 healthy children were investigated. Almost 50% of the patients showed laboratory signs of chronic inflammation. B19-DNA was amplified in 31% of patients' sera and 7% of the controls (P<0.0001). VP2-specific IgM was detectable in 50% of the patients' and 6% of control sera. NS1-specific immune reactions were linked to persistent B19-infection as indicated by the presence of viral genomes in the peripheral blood and of VP2-specific IgM years after disease onset. To estimate the severity of the disease and the clinical course, the number of affected and functionally impaired joints were noted and compared with the records from patients' initial visit in the hospital. Disease related complications were registered. Impairment of activities of daily living was assessed by Childhood Health Assessment Questionnaire (CHAQ)- and Munich Quality of Life Questionnaire (KINDL)-tests. During observation the clinical state of four patients worsened, 27 improved, the others remained stable. Twenty-four children were restricted in their daily activities.