The development of a murine model for Forcipomyia taiwana (biting midge) allergy.

BACKGROUND: Forcipomyia taiwana (biting midge) allergy is the most prevalent biting insect allergy in Taiwan. An animal model corresponding to the human immuno-pathologic features of midge allergy is needed for investigating the mechanisms and therapies. This study successfully developed a murine model of Forcipomyia taiwana allergy. METHODS: BALB/c mice were sensitized intra-peritoneally with midge extract on days 0, 7, 14, 21 then intra-dermally on days 28, 31 and 35. Serum midge-specific IgE, IgG1, and IgG2a were measured every 14 days by indirect ELISA. The mice were challenged intradermally with midge extract at day 40 and then sacrificed. Proliferation and cytokine production of splenocytes after stimulation with midge extract were determined by MTT assay and ELISA, respectively. The cytokine mRNA expression in response to midge stimulation was analyzed by RT-PCR. RESULTS: Serum IgE, total IgG, and IgG1 antibody levels against midge extract were significantly higher in the midge-sensitized mice than in the control mice. After the two-step sensitization, all mice in the midge-sensitized group displayed immediate itch and plasma extravasation reactions in response to challenge with midge extract. Skin histology from midge-sensitized mice showed marked eosinophil and lymphocyte infiltrations similar to that observed in humans. Stimulation of murine splenocytes with midge extract elicited significant proliferation, IL-4, IL-10, IL-13 and IFN-γ protein production, and up-regulation of mRNA in a dose-dependent manner in the midge-sensitized group, but not in the control group. CONCLUSIONS: A murine model of midge bite allergy has been successfully developed using a two-step sensitization protocol. The sensitized mice have very similar clinical and immunologic reactions to challenge with midge proteins as the reactions of human to midge bites. This murine model may be a useful platform for future research and the development of treatment strategies for insect bite allergy.

Mesenteric vasculitis causing ileocecal intussusception as the initial presentation of systemic lupus erythematosus: a case report.

Mesenteric vasculitis is one of the most devastating complications of systemic lupus erythematosus (SLE) and may produce a spectrum of complications, including ulceration, hemorrhage, bowel necrosis, perforation, serositis, and ascites. Intussusception is a process in which a segment of intestine invaginates into the adjoining intestinal lumen, causing bowel obstruction. Intussusception in association with SLE has rarely been reported. Here we report a case of SLE whose initial presentation was mesenteric vasculitis causing ileocecal intussusception.

Clinical, functional, and radiographic differences among juvenile-onset, adult-onset, and late-onset ankylosing spondylitis.

OBJECTIVE: The aim of our study was to compare the clinical, functional, and radiographic outcomes at different ages of onset in patients with ankylosing spondylitis (AS). METHODS: A total of 546 patients were enrolled consecutively and classified into 3 groups based on their age at symptom onset: (1) juvenile-onset AS (age ≤ 16 years; JoAS); (2) adult-onset AS (> 16 but < 40 years; AoAS); and (3) late-onset AS (≥ 40 years; LoAS). We compared the differences among the 3 groups. OR for disease outcomes were calculated and adjusted for sex, HLA-B27, and disease duration. RESULTS: There were 67 patients (12.3%) with JoAS, 460 (84.2%) with AoAS, and 19 (3.5%) with LoAS. Male sex and HLA-B27 were associated with a younger age at onset (p < 0.001). Compared to patients with AoAS, patients with JoAS were more likely to present with peripheral arthritis, while patients with JoAS and LoAS were less likely to have back pain at the onset of AS (p < 0.05). After controlling for multiple covariates, JoAS was found to be associated with a worse functional outcome and global assessment, and a high serum immunoglobulin A level (p < 0.05). Patients with JoAS had less lumbar spinal radiographic severity (p < 0.05). There were no statistical differences in clinical or functional outcome between the LoAS and AoAS groups. None of the LoAS patients had radiographic hip involvement. CONCLUSION: Sex and HLA-B27 are significantly associated with age at onset of AS. Both JoAS and LoAS have their distinctive symptoms/signs at onset and different disease outcomes.

Janus kinase/signal transducer and activator of transcription 3 signaling pathway is crucial in chemokine production from hepatocytes infected by dengue virus.

Hepatocytes are one of the important targets in dengue virus (DV) infection. Chemokines produced in DV infection play important immunopathogenic roles. We previously showed that DV infection can directly activate signal transducer and activator of transcription 3 (STAT3) in dendritic cells. In the present study, we examined the possible involvement of the Janus kinase (JAK)/STAT3 pathway in chemokine production from DV-infected hepatocytes. HepG2 cells were infected by DV. The activation of STAT3, nuclear factor-kappaB (NF-κB) and other transcription factors was determined by Western blotting or electrophoretic mobility shift assay. The concentrations of chemokines were measured by enzyme-linked immunosorbent assay. Virus titers were determined by plaque assays. A genetic manipulation with short hairpin RNA (shRNA) was applied to knock-down STAT3. Chemotaxis assays were used to evaluate cell migration. We observed that DV infection induced phosphorylation of STAT3 and its DNA-binding activity and such effects were attenuated by the inhibitor of JAK2 or JAK3. Blocking JAK2 or JAK3 reduced DV-induced cell migration and production of chemokines like interleukin-8 and regulated upon activation, normal T-cell expressed and secreted (RANTES). At high doses, the JAK2 but not JAK3 inhibitor could significantly inhibit DV production. Knocking down STAT3 with shRNA suppressed DV-induced STAT3, NF-κB and AP-1 activation. Furthermore, reduction of STAT3 suppressed DV-induced chemokine production and cell migration but had no effect on virus production. In conclusion, the results show that the JAK/STAT3 pathway is critical in chemokine production from DV-infected hepatocytes. Targeting this pathway may be of benefit in the therapy of DV-induced immunopathologies.

Predictors of longterm mortality in patients with and without systemic lupus erythematosus on maintenance dialysis: a comparative study.

OBJECTIVE: To compare the prognosis of patients with and without systemic lupus erythematosus (SLE) on dialysis and to determine the factors that affect survival after dialysis. METHODS: We used the Taiwan National Health Insurance Research Database (NHRI-NHIRD-99182) and collected data on patients who started maintenance dialysis between 2001 and 2003. Patients were followed from the initiation of dialysis until death, discontinuation of dialysis, or the end of 2008. We did a Kaplan-Meier analysis of the cohort and used multivariate Cox regression analysis to identify significant predictors of survival. RESULTS: Of the 22,394 dialysis patients studied, 303 (1.35%) had SLE. Hypertension and diabetes were the 2 most common comorbidities associated with dialysis for patients with and without SLE. After adjusting for age, sex, dialysis modality, and comorbidities, we found no significant survival difference between the 2 patient groups after 8 years of followup. Multivariate analysis showed that increased mortality in the patient group without SLE (p < 0.05) was associated with older age (≥ 45 years), male sex, initial choice of hemodialysis, diabetes mellitus, heart failure, coronary artery disease, cerebrovascular disease, and malignancy. In the patient group with SLE, independent predictors of mortality (p < 0.05) were older age (≥ 65 years), male sex, and diabetes mellitus. CONCLUSION: The longterm survival outcome was similar between patients with and without SLE who were on dialysis. The factors affecting patient mortality were not identical in these 2 groups.

Immunosuppressive effects and mechanisms of leflunomide in dengue virus infection of human dendritic cells.

BACKGROUND: Dengue virus (DENV) infection is a serious public health issue without specific treatment. We examined the potential immunomodulatory effects of leflunomide, a dihydroorotate dehydrogenase inhibitor commonly prescribed for arthritis, in DENV-stimulated monocyte-derived dendritic cells (mo-DCs). METHODS: mo-DCs were prepared from purified monocytes. Cytokine and chemokine concentrations were determined by enzyme-linked immunosorbent assay. Expression of cell surface markers or viral E protein was measured by flow cytometry. The activation of transcription factors and kinases was determined by electrophoretic mobility shift assays, Western blotting, or immunoprecipitation kinase assays. Chemotaxis assays were used to determine cell migration. RESULTS: Leflunomide at therapeutic concentrations inhibited cytokine and chemokine production from DENV-infected mo-DCs. Leflunomide suppressed mo-DC maturation by downregulating the expression of both CD80 and CD86. In addition, leflunomide inhibited DENV-induced mo-DC migration and mo-DC response to chemoattractants CCL19 and CCL21. Inhibition of mo-DC migration was likely due to the suppression of CCR7 expression on mo-DCs. These events were associated with the suppression of nuclear factor kappa B and activator protein-1 signaling pathways by leflunomide. CONCLUSIONS: Leflunomide preserves immunosuppressive effects, inhibiting activation of DENV-stimulated mo-DCs. Leflunomide may be helpful in the development of therapeutics for DENV infection.

Factors associated with radiographic spinal involvement and hip involvement in ankylosing spondylitis.

OBJECTIVES: To determine the factors associated with radiographic spinal involvement and hip involvement in ankylosing spondylitis (AS) and assess the influence of the damage seen in the radiographs on functional outcome in patients with AS. METHODS: We included 531 consecutive patients and recorded the clinical, laboratory, and radiographic data. Based on the spinal radiographs, patients were classified into 3 categories: (1) no spinal involvement; (2) spinal involvement without fusion; and (3) spinal involvement with fusion. Hip involvement was assessed by the Bath Ankylosing Spondylitis Radiology Hip Index and defined by a score of at least 2. Logistic regression analyses were used to investigate the factors associated with the radiographic spine and hip involvements. RESULTS: Ninety-eight (18.5%) patients had radiographic evidence of spinal fusion and 48 (9.0%) had radiographic evidence of hip involvement. Patients who had longer disease duration, elevated C-reactive protein levels, advanced sacroiliitis, and radiographic hip involvement were significantly more likely to have spinal fusion (P < 0.05). Elevated C-reactive protein levels and advanced sacroiliitis were also significantly associated with the presence of spinal involvement without fusion (P < 0.05). Early disease onset and more radiographic severity in the spine and sacroiliac joints were the predictors of radiographic hip involvement (P < 0.05). Patients with either spine or hip involvement had significantly higher Bath Ankylosing Spondylitis Functional Index scores (P < 0.001). CONCLUSION: There is a relationship between radiographic sacroiliitis, spinal fusion, and hip involvement in patients with AS. Damage to the spine and hip seen radiographically can contribute to functional impairment.

Association of bone morphogenetic proteins with spinal fusion in ankylosing spondylitis.

OBJECTIVE: To measure serum concentrations of bone morphogenetic proteins (BMP) in patients with ankylosing spondylitis (AS), and to investigate the relationship between BMP and clinical manifestations and radiographic changes. METHODS: We studied 60 consecutive AS patients with and 60 patients without spinal fusion. Spinal radiographs were assessed using the Bath Ankylosing Spondylitis Radiology Index (BASRI) and the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). Spinal fusion was defined as the presence of total bony bridging between 2 adjacent vertebral bodies in either the lumbar or cervical spine. Serum levels of BMP were determined by enzyme-linked immunosorbent assay. RESULTS: Patients with spinal fusion had higher serum levels of BMP-2 and BMP-4 than either the healthy controls or patients without spinal fusion (p < 0.001), but there was no difference between the latter 2 groups. Serum BMP-7, erythrocyte sedimentation rate, and C-reactive protein (CRP) levels were elevated in patients with spinal fusion compared with those without (p < 0.05). Serum BMP-4 and BMP-7 levels were higher in patients with hip involvement than in those without (p < 0.05). BMP-2 and BMP-4 levels had a significant correlation with spinal radiograph scores, especially for BASRI of the lumbar spine (r = 0.356 and 0.348, respectively, p < 0.001). CRP showed a significant correlation with spine BASRI and mSASSS scores (r = 0.261 and 0.260, respectively, p < 0.05). CONCLUSION: Rising levels of BMP in AS patients with spinal fusion and the positive correlation between BMP and spinal radiograph scores indicate that BMP may play a role in the process of spinal ankylosis. Serum levels of BMP may reflect radiographic progression of the spine and hip joints.

IgG4-related retroperitoneal fibrosis: the first reported case in a Chinese population.

Immunoglobulin G4 (IgG4)-related sclerosing disease is a newly recognized clinicopathological entity characterized by lymphoplasmacytic infiltration and varying degrees of fibrosis in various organs, with abundant IgG4-positive plasma cells in tissues. Patients usually exhibit multisystem involvement and often respond well to steroid and immunosuppressive therapy. However, this disease has been rarely reported in a Chinese population. We herein report a case of IgG4-related sclerosing disease solely presenting with retroperitoneal fibrosis that was effectively treated with systemic steroid therapy. To the best of our knowledge, this is the first reported case of IgG4-related retroperitoneal fibrosis in a Chinese population.

Systemic lupus erythematosus complicated with posterior reversible encephalopathy syndrome and intracranial vasculopathy.

Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic condition characterized by reversible vasogenic edema on neuroimaging. It is associated with various neurological manifestations, including headaches, vomiting, seizures, visual loss, altered mental status and focal neurological deficits. PRES mainly occurs in the setting of eclampsia, hypertension, uremia, malignancy, transplantation, autoimmune diseases and/or use of immunosuppressive drugs. This syndrome has been described in patients with systemic lupus erythematosus (SLE). PRES is a potentially reversible clinical-radiological entity; however, it can be complicated with vasculopathy, infarction or hemorrhage. Vasculopathy has been demonstrated to be a common finding in patients with SLE. We report the case of a woman with lupus nephritis and PRES whose diffuse vasculopathy was present on initial neuroimaging. Subsequent brain computed tomography scan demonstrated interval development of intraparenchymal hemorrhage and subarachnoid hemorrhage. To our knowledge, this unique brain image pattern has not been reported in SLE patients.

Plasmin immunization preferentially induces potentially prothrombotic IgG anticardiolipin antibodies in MRL/MpJ mice.

OBJECTIVE: To test the hypothesis, utilizing 2 experimental mouse models, that plasmin is an important autoantigen that drives the production of certain IgG anticardiolipin (aCL) antibodies in patients with the antiphospholipid syndrome. METHODS: BALB/cJ and MRL/MpJ mice were immunized with Freund's complete adjuvant in the presence or absence of human plasmin. The mouse sera were analyzed for production of IgG antiplasmin, IgG aCL, and IgG anti-beta(2)-glycoprotein I (anti-beta(2)GPI) antibodies. IgG monoclonal antibodies (mAb) were generated from the plasmin-immunized MRL/MpJ mice with high titers of aCL, and these 10 mAb were studied for their binding properties and functional activity in vitro. RESULTS: Plasmin-immunized BALB/cJ mice produced high titers of IgG antiplasmin only, while plasmin-immunized MRL/MpJ mice produced high titers of IgG antiplasmin, IgG aCL, and IgG anti-beta(2)GPI. Both strains of mice immunized with the adjuvant alone did not develop IgG antiplasmin or IgG aCL. All 10 of the IgG mAb bound to human plasmin and cardiolipin, while 4 of 10 bound to beta(2)GPI, 3 of 10 bound to thrombin, and 4 of 10 bound to the activated coagulation factor X (FXa). Functionally, 4 of the 10 IgG mAb inhibited plasmin activity, 1 of 10 hindered inactivation of thrombin by antithrombin III, and 2 of 10 inhibited inactivation of FXa by antithrombin III. CONCLUSION: Plasmin immunization leads to production of IgG antiplasmin, aCL, and anti-beta(2)GPI in MRL/MpJ mice, but leads to production of only IgG antiplasmin in BALB/cJ mice. IgG mAb generated from plasmin-immunized MRL/MpJ mice bind to various antigens and exhibit procoagulant activity in vitro. These results suggest that plasmin may drive potentially prothrombotic aCL in genetically susceptible individuals.

Some antiphospholipid antibodies recognize conformational epitopes shared by beta2-glycoprotein I and the homologous catalytic domains of several serine proteases.

OBJECTIVE: To test the hypothesis that some antiphospholipid antibodies (aPL) in patients with the antiphospholipid syndrome (APS) recognize a conformational epitope shared by beta2-glycoprotein I (beta2GPI; the major autoantigen for the antiphospholipid antibodies) and the homologous catalytic domains of several serine proteases (such as thrombin, activated protein C [APC], and plasmin) involved in hemostasis. METHODS: We generated 4 new IgG monoclonal aPL (2 screened against beta2GPI, 1 against thrombin, and 1 against protein C) from 2 APS patients. The monoclonal antibodies (mAb) were analyzed for binding to beta2GPI, thrombin, APC, and plasmin, as well as for anticardiolipin antibody (aCL) activity. To demonstrate a shared epitope between beta2GPI and a serine protease, 1 mAb was studied by cross-inhibition analysis. RESULTS: Both of the IgG anti-beta2GPI mAb bound to thrombin, APC, and plasmin. On the other hand, the 1 anti-thrombin mAb and the 1 anti-protein C mAb also bound to beta2GPI. Moreover, the binding of 1 cross-reactive mAb to beta2GPI was inhibited by alpha-thrombin (which contains only the catalytic domain of thrombin). All 4 mAb displayed aCL activity. CONCLUSION: Taken together with the findings that some aCL bind to several serine proteases that participate in hemostasis and share homologous catalytic domains, these data demonstrate that some aCL in APS patients recognize one or more conformational epitopes shared by beta2GPI and the catalytic domains of disease-relevant serine proteases.

Function of interleukin-20 as a proinflammatory molecule in rheumatoid and experimental arthritis.

OBJECTIVE: The pathogenesis of rheumatoid arthritis (RA) reflects an ongoing imbalance between proinflammatory and antiinflammatory cytokines. Interleukin-20 (IL-20) has proinflammatory properties for keratinocytes. In this study, we sought to determine whether IL-20 is involved in RA. METHODS: We analyzed IL-20 levels in synovial fluid from RA patients. IL-20 and its receptors were detected in RA synovial fibroblasts (RASFs), using immunohistochemical staining. The effect of IL-20 on endothelial cells, neutrophils, and RASFs was investigated using MTT and migration assays. The expression of IL-20 and its receptors in healthy rats and in rats with collagen-induced arthritis (CIA) was also analyzed. Soluble IL-20 receptor type I (sIL-20RI) or sIL-20RII was administered to rats with CIA by intramuscular electroporation, and the severity of arthritis was monitored. RESULTS: RA patients expressed significantly higher levels of synovial fluid IL-20 than did the rheumatic disease controls. IL-20 and its receptors were expressed in the synovial membranes and RASFs. IL-20 induced RASFs to secrete monocyte chemoattractant protein 1, IL-6, and IL-8, and it promoted neutrophil chemotaxis, RASF migration, and endothelial cell proliferation. Both IL-20 and IL-20RI were up-regulated in the rat CIA model. In vivo, electroporated sIL-20RI plasmid DNA decreased the severity of arthritis in the rats with CIA. CONCLUSION: IL-20 was up-regulated in the synovial fluid of RA patients and acted as a chemokine that attracted the migration of neutrophils and RASFs in vitro. The rat CIA model demonstrated that IL-20 was involved in the pathogenesis of arthritis, because sIL-20RI significantly reduced arthritis in rats with CIA. Thus, IL-20 may modulate the incidence and severity of arthritis and play important roles at local sites of inflammation.

Increased circulating CCR3+ type 2 helper T cells in house dust mite-sensitive Chinese patients with allergic diseases.

Chemokine receptor expression has been shown to be associated with the differentiation of T helper cells. The CCR3, CXCR4 and CCR5 expression on circulating T cells were studied in 30 house dust mite sensitive-patients with allergic diseases and in another 30 healthy controls. The expression was analyzed in CD4, CD8 and double negative (DN) T cells by triple fluorescence staining. In addition, intracellular cytokine staining was performed in the CCR3+ CD4+ T cells. Increased circulating portions of CCR3+ CD4+ T cells and CCR3+ DN T cells were found in these patients (p < 0.01). There was no statistically significant difference in the expression of CXCR4 and CCR5 on T cells. The follow-up data of the patients did not show a statistically significant change in the CCR3 expression. IL-4 was expressed within CCR3+ CD4+ T cells upon activation. The IL-4 secreting CCR3+ type 2 T helper cells may play a pathogenetic role in immune responses of house dust mite-sensitive Chinese patients with allergic diseases.

Correlation between the renal C1q deposition and serum anti-C1q antibody: a potential role of anti-C1q antibody in lupus nephritis.

The anti-C1q antibody has been shown to be associated with lupus patients with renal involvement. We conducted a study to determine the relationship between the serum anti-C1q titer and the renal deposition of C1q. The serum anti-C1q was measured in 26 healthy controls and 47 systemic lupus erythematosus (SLE) patients who were divided into 2 groups as non-nephritis and nephritis SLE. We analyzed the relationship between the anti-C1q titers and SLE, renal C1q staining and the WHO classification for lupus nephritis. The result revealed that the serum anti-C1q was present in 50.8% of the SLE patients, that its levels in those with renal involvement were significantly higher than in the normal control group (61.540 +/- 87.720 U/ml vs 15.750 +/- 2.530 U/ml, p = 0.005). Besides, the serum anti-C1q levels were higher in the patients with lupus nephritis with C1q deposition in the kidney tissue (66.038 +/- 91.141 U/ml vs 16.652 +/- 3.097 U/ml, p < 0.01). There seems to be evidence supporting that the autoantibody anti-C1q might play a pathogenic role in lupus nephritis.