Parvovirus B19 infection associated with the production of anti-neutrophil cytoplasmic antibody (ANCA) and anticardiolipin antibody (aCL)

Serum ANCA as Disease Biomarkers: Clinical Implications Beyond Vasculitis

Usually associated with autoimmune diseases, anti-neutrophil cytoplasmic antibodies are also detected in other conditions, such as infections, malignancies, and after intake of certain drugs. Even if the mechanisms of production and their pathogenic role have not been fully elucidated yet, ANCA are widely recognized as a clinically alarming finding due to their association with various disorders. While ANCA target several autoantigens, proteinase-3, and myeloperoxidase are the ones proved to be most frequently related to chronic inflammation and tissue damage in murine models. Albeit these autoantibodies could be present as an isolated observation without any implications, ANCA are frequently used in clinical practice to guide the diagnosis in a suspect of small vessel vasculitis. Conditions that should prompt the clinician to test ANCA status range from various forms of lung disease to renal or peripheral nervous system impairment. ANCA positivity in the presence of an autoimmune disease, especially rheumatoid arthritis, or connective tissue diseases, is frequently correlated with more clinical complications and treatment inefficacy, even in the absence of signs of vasculitis. For this reason, it has been postulated that ANCA could represent the final expression of an immune dysregulation rather than a pathogenic event responsible for organs damage. Recently, it has also been proposed that ANCA specificity (PR3 or MPO) could possibly define ANCA-associated vasculitides better than clinical phenotype. This review aims at summarizing the latest advancements in the field of ANCA study and clinical interpretation.

Fat Embolism Syndrome in Sickle Cell Disease

Fat embolism syndrome is a devastating complication of sickle cell disease resulting from extensive bone marrow necrosis and associated with high mortality rates, while survivors often suffer severe neurological sequelae. Despite that, the syndrome remains under-recognised and under-diagnosed. Paradoxically, it affects exclusively patients with mild forms of sickle cell disease, predominantly HbSC and HbSβ⁺. A significant number of cases occur in the context of human parvovirus B19 infection. We provide here a brief summary of the existing literature and describe our experience treating 8 patients in our institution. One patient had HbSS, 6 HbSC and 1 HbSβ⁺. All patients developed type I respiratory failure and neurological involvement either at presentation or within the first 72 h. The most striking laboratory abnormality was a 100-fold increase of the serum ferritin from baseline. Seven patients received emergency red cell exchange and 1 simple transfusion. Two patients (25%) died, 2 patients (25%) suffered severe neurological impairment and 1 (12%) mild neurological impairment on discharge, while 3 (38%) patients made a complete recovery. With long-term follow-up, 1 patient with severe neurological impairment and one patient with mild neurological impairment made dramatic improvements, making the long-term complete recovery or near complete recovery rate 63%. Immediate red cell exchange transfusion can be lifesaving and should be instituted as soon as the syndrome is suspected. However, as the outcomes remain unsatisfactory despite the increasing use of red cell exchange, we suggest additional therapeutic measures such as therapeutic plasma exchange and pre-emptive transfusion for high risk patients.

Infective endocarditis mimicking ANCA-associated vasculitis: does it require immunosuppressive therapy?: A case report and literature review

RATIONALE

In the course of endocarditis, the development of antineutrophil cytoplasmic antibody (ANCA)-mediated disease introduces the dilemma of determining the best treatment approach for immune conditions, whether immunosuppressant therapy should be added to antibiotic treatment has remained controversial.

PATIENT CONCERNS

A 33-year-old man presented with progressive fever lasting for 7 months, and swelling, pain, and purpura in the arms and legs. The patient showed multiple autoantibodies including cytoplasmic ANCA, antiproteinase 3, rheumatoid factor, and anti-beta 2 glycoprotein I. Blood culture was positive for viridans streptococcus, and renal biopsy revealed glomerulonephritis and interstitial nephritis.

DIAGNOSIS

Endocarditis caused by viridans streptococci, ANCA-associated vasculitis, and congenital ventricular septal defect.

INTERVENTIONS

In addition to effective antibiotics, he also received twice intravenous corticosteroids and intravenous immunoglobulin therapy, and a low dose of cyclophosphamide. At last, the patient received congenital ventricular septal defect repair and debridement.

OUTCOMES

The abnormal clinical manifestations, including renal failure and loss of strength, recovered rapidly with corticosteroid therapy in addition to antibiotic treatment. After 6 months without any medications, he remained asymptomatic and was able to live normally.

LESSONS

In this case with endocarditis and ANCA-associated vasculitis, we highlighted the importance of biopsy and immunosuppressive therapy. Histopathologic examination is required for diagnosis and treatment in such case. Identifying patients who have endocarditis and ANCA positivity with vasculitis pathologic features will require corticosteroid/immunosuppressives in addition to the antibiotics therapy.

Systematic review of case reports of antiphospholipid syndrome following infection

OBJECTIVE

The objective of this study was to conduct a systematic review of case reports documenting the development of antiphospholipid syndrome or antiphospholipid syndrome-related features after an infection.

METHODS

We searched Medline, EMBASE, Web of Science, PubMed ePubs, and The Cochrane Library - CENTRAL through March 2015 without restrictions. Studies reporting cases of antiphospholipid syndrome or antiphospholipid syndrome-related features following an infection were included.

RESULTS

Two hundred and fifty-nine publications met inclusion criteria, reporting on 293 cases. Three different groups of patients were identified; group 1 included patients who fulfilled the criteria for definitive antiphospholipid syndrome (24.6%), group 2 included patients who developed transient antiphospholipid antibodies with thromboembolic phenomena (43.7%), and group 3 included patients who developed transient antiphospholipid antibodies without thromboembolic events (31.7%). The most common preceding infection was viral (55.6%). In cases that developed thromboembolic events Human immunodeficiency and Hepatitis C viruses were the most frequently reported. Parvovirus B19 was the most common in cases that developed antibodies without thromboembolic events. Hematological manifestations and peripheral thrombosis were the most common clinical manifestations. Positive anticardiolipin antibodies were the most frequent antibodies reported, primarily coexisting IgG and IgM isotypes. Few patients in groups 1 and 2 had persistent antiphospholipid antibodies for more than 6 months. Outcome was variable with some cases reporting persistent antiphospholipid syndrome features and others achieving complete resolution of clinical events.

CONCLUSIONS

Development of antiphospholipid antibodies with all traditional manifestations of antiphospholipid syndrome were observed after variety of infections, most frequently after chronic viral infections with Human immunodeficiency and Hepatitis C. The causal relationship between infection and antiphospholipid syndrome cannot be established, but the possible contribution of various infections in the pathogenesis of antiphospholipid syndrome need further longitudinal and controlled studies to establish the incidence, and better quantify the risk and the outcomes of antiphospholipid-related events after infection.

Antiphospholipid Syndrome in Greece: Clinical and Immunological Study and Review of the Literature

The aim of this paper is to analyze the epidemiologic, clinical, and immunologic characteristics of the antiphospholipid syndrome (APS), primary or secondary, in autoimmune patients from Northern Greece. Sixty-seven patients with APS were included (9 men, 13.4%, and 58 women, 86.6%). Fifty-two (77.6%) patients had secondary APS and 15 had primary APS (22.4%). The mean age was 46.0 ±15.4 years and the mean follow-up period was 62.7 ±15.0 months. Medical records were retrospectively analyzed from January 1994 until December 2001, according to a preestablished protocol. Eight patients (11.9%) had arterial thrombosis, 12 (17.9%) had vein thrombosis, 12 (17.9%) had thrombocytopenia, 20 (29.8%) had neurologic disorders, and 51.6% of the women in reproductive age had, at least 2 fetal losses (higher frequency in primary APS). Thirty-six patients (53.7%) had increased levels of both immunoglobulin G (IgG) and IgM anticardiolipin antibodies (ACA), 19 (28.4%) had IgG ACA only, and 12 (17.7%) had IgM ACA only. Antinuclear antibodies (ANA) were detected in 46 (68.6%) patients, and antineutrophil cytoplasmic antibodies (ANCA) in 29 (43.3%). All patients were prophylactically treated with aspirin (50-100 mg/day) and low-molecular-weight heparin and/or intravenous immunoglobulins-IVIGs occasionally (pregnant women). The findings of this study are, generally, similar to those described by others. Miscarriages seem to be more frequent in women with primary APS (p<0.05), compared to other studies. Differences between these findings and those described by others concerning epidemiologic, clinical, or immunologic data are discussed.

The role of parvovirus B19 in the pathogenesis of autoimmunity and autoimmune disease

Human parvovirus B19 is a single-stranded DNA virus which preferentially targets the erythroblasts in the bone marrow. B19 infection commonly causes erythema infectiosum, arthralgia, fetal death, transient aplastic crisis in patients with shortened red cell survival, and persistent infection in people who are immunocompromised. Less common clinical manifestations include atypical skin rashes, neurological syndromes, cardiac syndromes, and various cytopenias. B19 infection has also been associated with development of a variety of different autoimmune diseases, including rheumatological, neurological, neuromuscular, cardiovascular, haematological, nephrological and metabolic. Production of a variety of autoantibodies has been demonstrated to occur during B19 infection and these have been shown to be key to the pathogenesis of the particular disease process in a significant number of cases, for example, production of rheumatoid factor in cases of B19-associated rheumatoid arthritis and production of anti-glutamic acid decarboxylase (GAD) in patients with B19-associated type 1 diabetes mellitus. B19 infection has also been associated with the development of multiple autoimmune diseases in 12 individuals. Documented mechanisms in B19-associated autoimmunity include molecular mimicry (IgG antibody to B19 proteins has been shown to cross react with a variety of recognised human autoantigens, including collagen II, keratin, angiotensin II type 1 receptor, myelin basic protein, cardiolipin, and platelet membrane glycoprotein IIb/IIIa), B19-induced apoptosis with presentation of self-antigens to T lymphocytes, and the phospholipase activity of the B19 unique VP1 protein.

Antineutrophil cytoplasmic antibody frequency in chronic hepatitis B patients

Background. Chronic hepatitis B (CHB) is a viral disease, common across the world, and associated with several extraintestinal manifestations including vasculitis. Antineutrophil cytoplasmic antibodies (ANCAs) are sensitive and specific markers for vasculitides. There is limited data available in the literature on whether ANCA formation is stimulated by CHB infection. In the present study we aimed to identify the frequency of ANCA in CHB patients. Methods. A total of 174 subjects were included in the study (87 CHB patients, 87 control subjects). Perinuclear-ANCA (P-ANCA), cytoplasmic-ANCA (C-ANCA), myeloperoxidase ANCA (MPO-ANCA), and proteinase 3-ANCA (PR3-ANCA) were studied. IFA was used for P-ANCA and C-ANCA assays, and ELISA was used for MPO-ANCA and PR3-ANCA assays. Results. ANCA positivity was high in both groups (31% in the CHB group and 26% among controls). There were no significant differences between the groups for P-ANCA and MPO-ANCA (P = 0.6 and P = 0.6, resp.). Frequency of borderline positive C-ANCA and all positive PR3-ANCA (positive + borderline positive) was significantly higher in the CHB group (P = 0.009 and P = 0.005, resp.). Conclusions. In the present study, the frequency of ANCA was high in both groups. The CHB group had a relatively higher frequency of ANCA positivity compared to controls. Borderline positive C-ANCA and positive PR3-ANCA were significantly higher in the CHB group. These results suggest that ANCA may have a high prevalence in Turkey. Patients with CHB should be evaluated particularly for C-ANCA and PR3-ANCA in the presence of vasculitic complaints and lesions.

Glomerular disease in patients with infectious processes developing antineutrophil cytoplasmic antibodies

To identify differences in treatment and outcome of various types of glomerulonephritis developing in the course of infections triggering antineutrophil cytoplasmic antibody (ANCA) formation, we analyzed published reports of 50 patients. Immunosuppressives were added to antibiotics in 22 of 23 patients with pauci-immune glomerulonephritis. Improvement was noted in 85% of 20 patients with information on outcomes. Death rate was 13%. Corticosteroids were added to antibiotics in about 50% of 19 patients with postinfectious glomerulonephritis. Improvement rate was 74%, and death rate was 26%. Two patients with mixed histological features were analyzed under both pauci-immune and post-infectious glomerulonephritis categories. In 9 patients with other renal histology, treatment consisted of antibiotics alone (7 patients), antibiotics plus immunosuppressives (1 patient), or immunosuppressives alone (1 patient). Improvement rate was 67%, permanent renal failure rate was 22%, and death rate was 11%. One patient with antiglomerular basement disease glomerulonephritis required maintenance hemodialysis. Glomerulonephritis developing in patients who became ANCA-positive during the course of an infection is associated with significant mortality. The histological type of the glomerulonephritis guides the choice of treatment. Pauci-immune glomerulonephritis is usually treated with addition of immunosuppressives to antibiotics.

Covalent attachment of functionalized cardiolipin on a biosensor gold surface allows repetitive measurements of anticardiolipin antibodies in serum

Antiphospholipid antibodies (aPL) are a relevant serological indicator of antiphospholipid syndrome (APS). A solid-state surface with covalently bound ω-amine-functionalized cardiolipin was established and the binding of β2-glycoprotein I (β2-GPI) was investigated either by use of surface plasmon resonance (SPR) biosensor, by electrically switchable DNA interfaces (switchSENSE) and by scanning tunneling microscopy (STM). STM could clearly visualize the attachment of β2-GPI to the cardiolipin surface. Using the switchSENSE sensor, β2-GPI as specific ligand could be identified by increased hydrodynamic friction. The binding of anti-cardiolipin antibodies (aCL) was detected against the ω-amine-functionalized cardiolipin-modified SPR biosensor (aCL biosensor) using sera from healthy donors, APS patients and syphilis patients. Our results showed that the aCL biosensor is a much more sensitive diagnostic device for APS patients compared to previous methods. The specificity between β2-GPI-dependent autoimmune- and β2-GPI-independent infection-associated types of aPLs was also studied and they can be distinguished by the different binding kinetics and patterns.

Human parvovirus B19 nonstructural protein NS1 enhanced the expression of cleavage of 70 kDa U1-snRNP autoantigen

Background

Human parvovirus B19 (B19) is known to induce apoptosis that has been associated with a variety of autoimmune disorders. Although we have previously reported that B19 non-structural protein (NS1) induces mitochondrial-dependent apoptosis in COS-7 cells, the precise mechanism of B19-NS1 in developing autoimmunity is still obscure.

Methods

To further examine the effect of B19-NS1 in presence of autoantigens, COS-7 cells were transfected with pEGFP, pEGFP-B19-NS1 and pEGFP-NS1K334E, a mutant form of B19-NS1, and detected the expressions of autoantigens by various autoantibodies against Sm, U1 small nuclear ribonucleoprotein (U1-snRNP), SSA/Ro, SSB/La, Scl-70, Jo-1, Ku, and centromere protein (CENP) A/B by using Immunoblotting.

Results

Significantly increased apoptosis was detected in COS-7 cells transfected with pEGFP-B19-NS1 compared to those transfected with pEGFP. Meanwhile, the apoptotic 70 kDa U1-snRNP protein in COS-7 cells transfected with pEGFP-B19-NS1 is cleaved by caspase-3 and converted into a specific 40 kDa product, which were recognized by anti-U1-snRNP autoantibody. In contrast, significantly decreased apoptosis and cleaved 40 kDa product were observed in COS-7 cells transfected with pEGFP-NS1K334E compared to those transfected with pEGFP-B19-NS1.

Conclusions

These findings suggested crucial association of B19-NS1 in development of autoimmunity by inducing apoptosis and specific cleavage of 70 kDa U1-snRNP.

Prolonged infections associated with antineutrophil cytoplasmic antibodies specific to proteinase 3 and myeloperoxidase: diagnostic and therapeutic challenge

Chronic infections may mimic antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV). We investigated which markers may help in the diagnosis and the prognosis of infections associated with proteinase 3 (PR3) and myeloperoxidase (MPO)-ANCA. In this study (1993-2008)--with an average follow-up of 5.1 years--we compared 66 AAV patients with 17 PR3 and/or MPO-ANCA-positive patients with protracted bacterial (11/17) or viral (6/17) infections. Seven of 17 patients had subacute bacterial endocarditis (SBE), while six of 17 patients had various autoimmune manifestations of chronic hepatitis C virus (HCV) infection. We determined ANCA, antinuclear antibodies, anti-PR3, anti-MPO, anticardiolipin (aCL), antibeta 2 glycoprotein I (beta2-GP I), cryoglobulins, C3, and C4. Patients with infections were younger than AAV patients (p < 0.01). There was no difference in frequency of renal and skin lesions. AAV patients more frequently had pulmonary and nervous system manifestations (p < 0.01). Patients with infections more frequently had dual ANCA (high PR3, low MPO), aCL, anti-beta2-GP I, cryoglobulins, and hypocomplementemia (p < 0.001). Immunosuppressive therapy (IST) was used in five 17 patients who had persistently high ANCA, cryoglobulinemia, and hypocomplementemia. There was no difference in frequency of lethality and renal failure in the two study groups. In patients who are PR3- and/or MPO-ANCA positive, SBE and HCV infection should be excluded. Although similar in renal and skin manifestations in comparison to AAV, only patients with infections developed multiple serological abnormalities. In patients with infections, concomitant presence of ANCA, cryoglobulins, and hypocomplementemia was associated with severe glomerulonephritis. The serological profile should be repeated after specific antimicrobial or surgical therapy, since some cases might require IST.

Hypotheses on the etiology of antineutrophil cytoplasmic autoantibody associated vasculitis: the cause is hidden, but the result is known

The first description of what is now known as antineutrophil cytoplasmic autoantibody-associated necrotizing vasculitis appeared more than 140 yr ago. Since then, many aspects of the pathogenic pathway have been elucidated, indicating the involvement of antineutrophil cytoplasmic autoantibodies, but why antineutrophil cytoplasmic autoantibodies are produced in the first place remains unknown. Over the years, many hypotheses have emerged addressing the etiology of antineutrophil cytoplasmic antibody production, but no exclusive factor or set of factors can so far be held responsible. Herein is reviewed the most influential hypotheses regarding the causes of antineutrophil cytoplasmic antibody-associated vasculitis with the aim of placing in an epidemiologic background the different hypotheses that are centered on environmental and genetic influences.

Induction of antiphospholipid antibodies and antiphospholipid syndrome-like autoimmunity in naive mice with antibody against human parvovirus B19 VP1 unique region protein

BACKGROUND

Previous studies have postulated a connection between human parvovirus B19 (B19) infection and anti-phospholipid antibodies (APhL). B19 infection and anti-phospholipid syndrome (APS) exhibit congruent symptoms. Recently, phospholipase A2 (PLA2)-like activity has been linked to the VP1 unique region (VP1u) of B19. However, the precise role of B19-VP1u in pathogenesis of autoimmunity is still obscure.

METHODS

To elucidate the roles of VP1u in B19 infection and autoimmunity, the reactivity of B19-VP1u proteins with various autoantibodies were evaluated by ELISA and immunoblotting. Rabbits were immunized with purified recombinant B19-VP1u protein to generate anti-sera. Absorption experiments were conducted to determine the binding specificity of rabbit anti-sera against B19-VP1u, cardiolipin (CL) and beta-2-glycoprotein I (beta2GPI). Moreover, the effects of passive transfer of polyclonal rabbit anti-B19-VP1u IgG antibodies on platelets, activated partial thromboplastin time (aPTT), and autoantibodies were assessed.

RESULTS

Autoantibodies against CL, beta2GPI, and phospholipid (PhL) in sera from patients with B19 infection, were cross-reactive with B19-VP1u. Consistently, sera from rabbits immunized with recombinant B19-VP1u protein displayed raised detectable immunoglobulins against B19-VP1u, CL, beta2GPI and PhL. Additionally, the mice immunized with anti-B19-VP1u IgG developed thrombocytopenia, prolongation of aPTT, and autoantibody against beta2GPI and PhL.

CONCLUSIONS

These experimental results suggested the association between B19-VP1u and production of anti-beta2GPI antibodies, APhL, and APS-like autoimmunity. Altogether, it may provide a clue in understanding the role of B19-VP1u in inducing autoantibodies and B19-associated APS manifestations.

Infection and musculoskeletal conditions: Viral causes of arthritis

Several viruses cause postinfectious arthritis. The disease is a typical manifestation of arthritogenic alphaviruses, rubella virus and human parvovirus B19. In addition, arthritis is not uncommon after infection by HIV, cytomegalovirus, hepatitis B virus, hepatitis C virus, or Epstein-Barr virus (EBV). Also prolonged arthritis may result from viral infections, particularly with alphaviruses and human parvovirus B19. Viruses such as EBV and B19 may have significant roles in initiating chronic arthropathies, which in some cases may be indistinguishable from rheumatoid arthritis.

The association of VP1 unique region protein in acute parvovirus B19 infection and anti-phospholipid antibody production

BACKGROUND

Previous studies have postulated a connection between human parvovirus B19 (B19) infection and anti-phospholipid antibodies (aPL). Recently, the phospholipase domain of B19 has been linked to B19-VP1 unique region (VP1u). To elucidate the roles of VP1u in B19 infection and aPL production, the major reactivity of anti-B19-VP1u, anti-cardiolipin antibody (aCL), and anti-beta2-glycoprotein I (beta2GPI) antibody was evaluated.

METHODS

Sera from 102 clinically suspected cases of B19 infection were analyzed by nested PCR and ELISA. Humoral responses of anti-B19-VP1u and anti-B19-VP1uD175A IgM/IgG antibodies, aCL and the anti-beta2GPI antibody were assessed by Western blot and ELISA. Absorption experiments were also performed to determine the binding specificity of immunoglobulins to B19-VP1u, CL and beta2GPI.

RESULTS

Sera from patients with the diagnostic pattern DNA+/IgM+/IgG+ had a high frequency (57%) for recognition of CL and beta2GPI. Furthermore, adsorption experiments were performed by adding purified B19-VP1u, which partially suppressed the reactivity of anti-B19VP1u to CL and beta2GPI.

CONCLUSIONS

Serum from patients with acute B19 infection has a high frequency in recognition of CL and beta2GPI, and the phospholipase domain observed in the B19-VP1u may have contributed to the production of aPL. These findings may provide a clue for understanding the roles of B19-VP1u in B19 infection and aPL production.

Antineutrophil cytoplasmic antibodies

Much like other autoantibodies (eg, anti-double stranded DNA in systemic lupus erythematosus or antiglomerular basement membrane antibodies in Goodpasture's syndrome), antineutrophil cytoplasmic antibodies (ANCA) have provided doctors with a useful serological test to assist in diagnosis of small-vessel vasculitides, including Wegener's granulomatosis, microscopic polyangiitis, Churg-Strauss syndrome, and their localised forms (eg, pauci-immune necrotising and crescentic glomerulonephritis). 85-95% of patients with Wegener's granulomatosis, microscopic polyangiitis, and pauci-immune necrotising and crescentic glomerulonephritis have serum ANCA. ANCA directed to either proteinase 3 or myeloperoxidase are clinically relevant, yet the relevance of other ANCA remains unknown. Besides their diagnostic potential, ANCA might be valuable in disease monitoring. In addition, data seem to confirm the long-disputed pathogenic role of these antibodies. Present treatments for ANCA-associated vasculitis are not free from side-effects and as many as 50% of patients relapse within 5 years. Accurate understanding of the key pathogenic points of ANCA-associated vasculitis can undoubtedly provide a more rational therapeutic approach.

Increased expression and secretion of interleukin-6 in human parvovirus B19 non-structural protein (NS1) transfected COS-7 epithelial cells

Human parvovirus B19 (B19) has been associated with a variety of autoimmune diseases, including rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). We have demonstrated previously that B19 non-structural protein (NS1) induced apoptosis through the mitochondria cell death pathway in COS-7 epithelial cells and that B19 NS1 may play a role in the pathogenesis of autoimmune diseases. In order to examine the expression profiles of cytokines and chemokines in B19 NS1 transfected COS-7 cells, we constructed the NS1 gene in the pEGFP-C1 vector named enhanced green fluorescence protein gene (EGFP)-NS1. COS-7 cells were transfected with EGFP or EGFP-NS1 plasmid. The expression profiles of cytokines and chemokines, including interleukin (IL)-1beta, IL-5, IL-6, IL-8, IL-10, tumour necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta, granulocyte-macrophage colony-stimulating factor (GM-CSF), growth-related oncogene alpha (GROalpha), interferon gamma-inducible protein (IP)-10, stromal cell derived factor (SDF)-1, macrophage inflammatory protein (MIP)-1beta, monocyte chemoattractant protein (MCP)-1, regulated upon activation normal T cell expressed and secreted (RANTES), Fractalkine, CX3CR1, CCR2, CCR5 and CCR11 were examined in COS-7 cells, EGFP and EGFP-NS1 transfected cells using enzyme-linked immunosorbent assay (ELISA) or reverse transcription-polymerase chain reaction (RT-PCR). Increased expression and levels of IL-6 were found in EGFP-NS1 transfected cells using RT-PCR and ELISA. There were no significant increases in the expression of IL-1beta, IL-8, IP-10, SDF-1, RANTES, Fractalkine, CX3CR-1, CCR2, CCR5, CCR11, TNF-alpha, GM-CSF and TGF-beta using RT-PCR. There were no significantly increased levels of IL-5, IL-10, TNF-alpha, TGF-beta, GROalpha, MIP-1beta and MCP-1 found by ELISA in this study. Our results show that increased expression and secretion of IL-6 in B19 NS1 transfected epithelial cells may play a role in the pathogenesis of autoimmune diseases.

Childhood microscopic polyangiitis associated with MPO-ANCA

We reviewed the clinical, histological and serological parameters of microscopic polyangiitis (MPA) associated with antineutrophil cytoplasmic antibodies (ANCA) specific to myeloperoxidase (MPO). Six girls and one boy aged 12.0+/-2.6 years (7-15 years) met the following inclusion criteria: (1) clinical manifestations of systemic small vessel involvement; (2) histological demonstration of pauci-immune necrotizing glomerulonephritis; and (3) serological findings of increased concentration of MPO-ANCA by ELISA test. The main clinical manifestations were: influenza-like symptoms (100%), hematuria/proteinuria (100%), purpura (100%), pulmonary-renal syndrome (57%), acute renal failure (ARF) (29%), ischemic cerebral insults (29%), and necrotizing vasculitis of the skin (29%). All patients underwent renal biopsy examined by immunohistochemistry with expression of alpha-smooth muscle actin (alpha SMA) in glomerular and interstitial spaces. Patients were followed from 6 months to 5.5 years (35.4+/- 23.2 months). None of the patients died. Two of seven children who had ARF progressed to end stage renal disease; one developed chronic renal failure, and four normalized renal function. ARF and central nervous system involvement at presentation were parameters of poor renal outcome. A high score of fibro-cellular glomerular crescents was associated with worse prognosis. Early treatment enables a favorable prognosis of MPO-ANCA-associated MPA in children.

Low seroprevalence and poor specificity of antineutrophil cytoplasmic antibodies in tuberculosis

OBJECTIVES

Recently published findings suggested that antineutrophil cytoplasmic antibodies (ANCA), particularly those with a cytoplasmic (C-ANCA) labelling pattern and targeting proteinase 3 (anti-PR3), might be markers of tuberculosis (TB). This is a critical issue, because C-ANCA/anti-PR3 were considered to be a highly specific hallmark of Wegener's granulomatosis or microscopic polyangiitis and because TB may clinically mimic Wegener's granulomatosis. We therefore undertook a study with the aim of investigating further the prevalence and specificity of ANCA in TB.

METHODS

We evaluated serum samples from 67 patients diagnosed with culture-proven TB and 10 previously untested control samples from patients known to be ANCA positive (four Wegener's granulomatosis and two microscopic polyangiitides) or negative. All 77 sera were screened for ANCA using commercially available indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA) for anti-PR3 and antimyeloperoxidase (MPO). IIF-positive and anti-PR3- and anti-MPO-negative sera were also tested for bactericidal/permeability-increasing protein, lactoferrin, elastase and cathepsin G specificities with commercially available ELISA.

RESULTS

IIF detected ANCA in seven (10%) of the TB sera, including three C-ANCA and four atypical perinuclear-labelling ANCA. Only one IIF-negative specimen was anti-PR3 positive in ELISA. ANCA testing of the control sera yielded IIF and ELISA results concordant with previous findings, except for one borderline ELISA.

CONCLUSION

Our results indicate that TB is associated with low ANCA seroprevalence and poor specificity, with no test serum showing combined C-ANCA/anti-PR3 activity. In a clinical setting of Wegener's granulomatosis/TB mimicry, such combined reactivity would seem to be more suggestive of Wegener's granulomatosis.

TRALI after the infusion of marrow cells in a patient with acute lymphoblastic leukemia

BACKGROUND

TRALI is one of the most serious, life-threatening complications after blood transfusion. Antibodies against neutrophils or HLA molecules from the donor are thought to be the primary causative agents. Rarely, antibodies in the recipient may react with transfused neutrophils and initiate the same events, which raises the possibility that TRALI may also occur in an allogeneic PBPC transplantation setting.

CASE REPORT

A 30-year-old Japanese man with acute lymphoblastic leukemia developed TRALI immediately after the infusion of marrow cells from an unrelated donor. The infusion was suspended, and he gradually improved after receiving steroids and oxygen support. The next day, the remaining cells, which were separated to MNCs, were infused with no reactions. He then recovered over 5 days without the use of mechanical ventilation.

RESULTS

Laboratory evaluation disclosed the presence of antibodies to neutrophils in his sera sampled after transplantation, but not in the donor's marrow graft. Hence, antibodies to neutrophils in the recipient may have reacted with neutrophils in the graft and contributed to the development of TRALI.

CONCLUSION

This is the first reported case of TRALI after allogeneic BMT. TRALI should be recognized as a rare but serious complication in allogeneic hematopoietic stem cell transplantation.

Tumor necrosis factor (TNF)alpha and its soluble receptor (sTNFR) p75 during acute human parvovirus B19 infection in children

Human parvovirus B19 (HPV) has been shown to be involved in the pathogenesis of various connective tissue and autoimmune diseases. In order to gain more information on HPV possible role in these diseases, we have investigated some immune responses in patients with acute HPV infection, mainly the secretion of the proinflammatory cytokine tumor necrosis factor (TNF)alpha and it's antagonist--the soluble TNF receptor (sTNFR) p75. Thirteen children with acute HPV infection and 13 healthy volunteers were investigated for the presence of autoantibodies, lymphocyte subpopulation counts, levels of total immunoglobulins, IgG subclasses and complement. The levels of TNFalpha and sTNFR p75 were determined in serum and conditioned medium (CM) from unstimulated and LPS stimulated peripheral blood mononuclear cell (PBMC) cultures. There was no difference between patients and controls regarding autoantibodies, lymphocytes, immunoglobulins, IgG subclasses and complement. A significant imbalance between TNFalpha and sTNFR p75 was found in the patients group. TNFalpha concentrations were significantly higher both in sera and in CM from the patients as compared with the controls. The levels of sTNFR concentrations were either similar (in sera) or significantly lower (in CM) in the patients compared with the controls. The TNF index, representing the biologically available TNFalpha, was significantly higher in patient's sera and CMs. In view of these results, it is conceivable that infection with human HPV in otherwise healthy children may lead to a proinflammatory state. The presence of high levels of biologically available TNFalpha, in susceptible individuals, may in turn play a role in the pathogenesis of systemic autoimmune diseases in HPV infected individuals.

Anticardiolipin antibodies in chronic viral hepatitis. Do they have clinical consequences?

Antiphospholipid antibodies are a heterogeneous group of acquired autoantibodies that react with anionic phospholipids, such as cardiolipin. Anticardiolipin antibodies (ACAs) are frequently found in patients with systemic lupus erythematosus and other autoimmune disorders and can react with the phospholipid alone or bound to the cofactor beta2-glycoprotein-I. This latter form of cofactor-dependent ACAs is strongly associated with the occurrence of thrombotic events. ACAs have been observed to occur in both chronic hepatitis B and chronic hepatitis C as well as in other viral infections and in neoplastic diseases. In viral infection, ACAs are generally cofactor independent and may represent an epiphenomenon of the infection. Some studies, however, have found an increased incidence of thrombotic disorders in patients with chronic hepatitis C virus (HCV) who manifest ACA positivity suggesting that the presence of these autoantibodies may predispose to thrombosis in specific HCV-infected patients. In conclusion, ACAs are commonly found in patients with chronic viral infection but their pathogenetic role and the mechanisms that stimulate their production have not yet been clarified.

Parvoviruses and blood products

Erythrovirus B19 (B19), a small isocahedral, non-enveloped virus (18-26 nm), is a ubiquitous infection agent in industrialised countries. Depending on the infected host, B19 has a wide range of disease manifestations from asymptomatic (the majority) to severe, including persistent infection. The risk of B19 transmission by blood products is enhanced by a high virus titre in the infected donor, by pooling of a large number of donations, and by the virus's resistance to effective inactivation methods such as heat and solvent-detergent treatments. B19-DNA has been detected in single donations, in manufacture plasma pools and in plasma derivatives (clotting factors, albumin, antithrombin III and immunoglobulins) produced by different processes. B19 transmission is mostly found in patients treated with clotting factors, as shown by a higher seroprevalence in treated haemophiliacs, by the presence of B19 DNA, and by active seroconversion. Chronic B19 infection can successfully be treated with polyvalent intravenous immunoglobulins. The key role of neutralising anti-B19 antibodies and of the virus titre has been demonstrated by B19 transmission after infusion of several B19-positive plasma batches treated with solvent-detergent. Two strategies can be followed to reduce the B19 risk: (1) reducing the viral load in the manufacture plasma pool by discarding B19-DNA-positive donations; (2) developing new strong virus inactivation methods. The physico-resistant properties of B19 make it a good model for new emergent viruses capable of infecting blood products.

Human parvovirus B19 infection in patients with systemic lupus erythematosus

OBJECTIVE

The clinical significance of the presence of B19 DNA in patients with SLE was studied.

METHODS

Sera from 72 patients with systemic lupus erythematosus (SLE), 23 patients with rheumatoid arthritis (RA), 18 patients with Sjögren's syndrome (SS), eight patients with Raynaud's phenomenon (RP), five patients with primary biliary cirrhosis (PBC), five patients with polymyositis (PM), four patients with erythema infectiosum (EI) and 22 normal controls were examined for parvovirus B19 (B19) infection by serological assays, nested PCR and Southern blotting.

RESULTS

Parvovirus B19 DNA was detected in 17 of 72 patients with SLE and in three of four patients with EI, but not in patients with other systemic rheumatic diseases. Of the 17 patients with B19 DNA, only one had IgG anti-B19 antibody and two had IgM anti-B19 antibodies, whereas IgG and IgM anti-B19 antibodies were detected in 27 (49.1%) and 21 (38.2%) of 55 SLE patients without B19 DNA respectively. All sera from the patients with EI contained both IgG and IgM anti-B19 antibodies. B19 DNA was found more commonly in sera from SLE patients without anti-B19 antibodies than in those with anti-B19 antibodies (P<0.05).

CONCLUSIONS

B19 infection in patients with SLE may be due to lack of anti-B19 antibodies because of either the immunocompromised nature of the host or the use of immunosuppressive drugs. There was a higher prevalence of hypocomplementaemia and RP in patients with parvovirus B19 viraemia than in those without parvovirus B19 viraemia.