Diagnostic Accuracy of Anticarbamylated Protein Antibodies in Established Rheumatoid Arthritis: A Monocentric Cross-Sectional Study.

OBJECTIVE: To evaluate the diagnostic accuracy of anticarbamylated protein antibodies (CarP), alone and in combination with traditional biomarkers (rheumatoid factor [RF] and anticitrullinated peptide antibodies [ACPA]), in established rheumatoid arthritis (RA). METHODS: A commercially available enzyme-linked immunosorbent assay (ELISA) kit was used to assess CarP concentrations in serum samples of 200 established RA and 206 controls (115 healthy donors and 55 patients with other rheumatic diseases). Main outcome measures were sensitivity, specificity, and area under the curve (AUC; 95% confidence interval [CI]). Difference in accuracy was evaluated by comparison of the respective AUCs. RESULTS: A serum CarP cut-off of 1.47 ng/ml or more differentiated patients with RA from controls with 30% sensitivity, 97.1% specificity, and good accuracy (AUC[95%CI] = 0.83[0.79-0.86], P < 0.0001). However, it showed moderate diagnostic accuracy in seronegative RA patients: sensitivity 17.9%, specificity 96.9%, and AUC (95% CI) = 0.69 (0.63-0.75). The diagnostic accuracy of CarP_ACPA and CarP_RF combinations was significantly superior to that of ACPA and RF alone (P < 0.0001 and P = 0.015, respectively), but not to that of ACPA_RF combination (P = 0.089) In addition, the CarP_ACPA_RF combination did not improve the diagnostic accuracy of the ACPA_RF combination (AUC mean difference [95% CI] = 0.006 [-0.001 to 0.015], P = 0.10). The number of positive autoantibodies (0, 1, 2, or 3) was not significantly associated with moderate-severe disease (Disease Activity Score-28 [DAS-28] > 3.2) in adjusted multiple regression analysis. CONCLUSION: CarP has good diagnostic accuracy in established RA but not in seronegative RA. The addition of CarP to ACPA and RF alone or in combination does not significantly enhance the diagnostic accuracy of ACPA_RF combination.

Peripheral blood CD8+ T-cell profiles in patients with psoriatic arthritis: a cross-sectional case-control study.

OBJECTIVE: While CD4+ T-cells are traditionally regarded as the main pathogenic T-cell subpopulation in psoriatic arthritis (PsA), the role of circulating CD8+ T-cells remains poorly characterized. We evaluated the differential representation of CD8+ T-cell subpopulations in peripheral blood (PB) of PsA patients. PATIENTS AND METHODS: CD8+IL-17+, CD8+IFNγ+ and CD8+IL-17-IL-22+ T-cells were evaluated by flow-cytometry in 25 consecutive PsA patients, 7 rheumatoid arthritis (RA) patients, 16 patients with psoriasis, and 26 healthy controls (HC). RESULTS: We observed a significant expansion of circulating IFN-γ producing CD8+ T-cells in PsA when compared to psoriasis [21.2 (6.9-55.8)% vs. 3.8 (0.7-11.8)%, p < 0.0001] and HC samples [21.2 (6.9-55.8)% vs. 4.05 (0.44-19.8)%, p < 0.0001]. A frequency of circulating IFN-γ producing CD8+T-cells ≥ 9% distinguished PsA from psoriasis patients with a specificity of 84% and a sensitivity of 87.5% [AUC = 0.9 (0.80-0.99), p < 0.0001]. In addition, we found a significant expansion of circulating IL-17 producing CD8+ T cells in RA patients when compared to PsA, psoriasis and HC samples. By contrast, there were no significant between-group differences in the prevalence of circulating IL-22 producing CD8+ T-cells. In PsA patients there was a significant correlation between number of swollen joints and frequency of circulating IFN-γ producing CD8+ T-cells, and between extent and severity of psoriasis and frequency of circulating IL-17 producing CD8+ T-cells. CONCLUSIONS: Circulating IFNγ-producing CD8+ T-cells are raised in PsA when compared to psoriasis, suggesting a potential pathogenetic involvement of CD8+ T-cells and IFNγ production in chronic joint inflammation and damage. The significant enrichment of circulating IL-17 producing CD8+ T-cells in RA when compared to PsA warrants functional characterization and confirmation in larger studies. We found no significant enrichment of circulating IL-22 producing CD8+ T-cells in PsA, RA and psoriasis.

Identification of a HERV-K env surface peptide highly recognized in Rheumatoid Arthritis (RA) patients: a cross-sectional case-control study.

Endogenous retroviruses (HERV) are believed to be pathogenic in several autoimmune diseases. Among them, HERV-K viruses have been reported recently to be involved in the pathogenesis of rheumatoid arthritis (RA). In this study we have explored the role of humoral immune response against HERV-K as a potential pathogenetic mechanism in RA. Four different peptides from the extracellular portion of the env protein of HERV-K (env-su19-37 , env-su109-126 , env-su164-186 , env-su209-226 ) were selected by bioinformatic analysis on the basis of their putative immunogenicity. Indirect enzyme-linked immunosorbent assay (ELISA) was then carried out to quantify antibodies against those peptides on blood samples of 70 consecutive RA patients and 71 healthy controls (HC). Differences between the two groups were analysed using the Mann-Whitney test. Potential correlations between RA laboratory, clinical descriptors and immunoglobulin (Ig)G levels were explored by bivariate regression analysis. Serum autoantibodies against one of four tested peptides of HERV-K (env-su19-37 ) were significantly higher in RA than in HC (19 versus 3%, P = 0·0025). Subgroup analysis showed no association between anti-HERV-K peptide humoral response and clinical, serological and clinimetric RA disease descriptors. Serum from RA patients in our series reacted significantly against HERV-K env-su19-37 peptide in comparison to the general population suggesting a role for the HERV-K- related, secondary antigenic-driven immune response in the pathogenesis of RA. Further studies are needed to confirm these results and to explore the role of this HERV-K surface peptide as a potential therapeutic target.

Mycobacterium tuberculosis lipoarabinomannan antibodies are associated to rheumatoid arthritis in Sardinian patients.

Little is known regarding the environmental factors at play in igniting rheumatoid arthritis (RA) autoimmunity, although an association between Mycobacteria and RA has been documented. This pilot study focused on examining a possible involvement of Mycobacterium tuberculosis (MTB) and Mycobacterium avium ss. paratuberculosis (MAP) in RA. We measured out the serum levels of IgG antibody against different mycobacterial antigens in Sardinian patients and controls, by an enzyme-linked immunosorbent assay. The population study was composed of 61 RA patients under different therapies and 52 healthy controls, whereas the antigens tested were MTB lipoarabinomannan (ManLAM), MAP heath shock protein 70, and MAP protein tyrosine phosphatase. The frequencies of anti-ManLAM antibodies were higher in the RA group (23 %) compared to the healthy controls (5.7 %) (AUC = 0.7; p < 0.0001), whereas serum reactivity to MAP antigens was not observed. ManLAM antigen was also detected in the plasma of three RA patients (which were anti-ManLAM antibody positive) by Western blot analysis using anti-Man-LAM monoclonal antibodies. The data produced corroborate the hypothesis of a potential association between MTB ManLAM and RA disease, but so far, further studies are necessary to understand its role in RA pathogenesis.

Genetics of Behçet's disease in Sardinia: two distinct extended HLA haplotypes harbour the B*51 allele in the normal population and in patients.

OBJECTIVES: To define the contribution of HLA genes and extended HLA haplotypes to the susceptibility to Behçet's disease (BD) in Sardinia. METHODS: Forty-five unrelated Sardinian patients with BD, diagnosed according to the ISG criteria, 45 HLA-B*51 positive and 185 unselected healthy controls were enrolled in the study. DNA samples were typed for HLA class I and class II alleles and genotyped for microsatellites (MICA-TM) and single-nucleotide polymorphisms (rs1264457 HLA-E; rs2281820 motilin; rs1799724 at -857, rs361525 at -238 TNF-alpha) spanning the HLA region. RESULTS: HLA-B*5101 was confirmed as conferring susceptibility to BD (pc=0.0042; OR=4.4; 95% CI=2.0 to 9.6). It is noteworthy that in Sardinia this allele was found more frequently within a haplotype (HLA-A2; -Cw2; -B*5101; -DRB1*11; -DQA1*05; - DQB1*03) that reached its highest frequency in patients with BD. Linkage disequilibrium analysis showed the existence of an additional B*51 haplotype (HLA-A2; -Cw2; -B*5101; -DRB1*04; -DQA1*03; -DQB1*03) not associated with susceptibility to the disease. CONCLUSIONS: In Sardinia, the BD-associated HLA-B*5101 allele is inherited as part of two distinctive haplotypes differently distributed in patients and controls. These findings can be interpreted as suggestive of the presence of additional genes within the MHC region conferring susceptibility to BD. The hypothesis that an environmental pressure could have contributed to the preservation of the BD-associated HLA haplotype in Sardinia is also discussed.

Antioxidant effect of Iloprost: current knowledge and therapeutic implications for systemic sclerosis.

Many lines of independent research have pointed out the role of oxidative stress as a fascinating pathogenic link between the three main hallmarks of systemic sclerosis (SSc), viz. humoral and cellular immunity activation, microvascular damage and widespread tissue fibrosis. Therefore counteracting oxidative stress may have a favourable impact on clinical features and progression of disease. It is becoming clearer that Iloprost, a synthetic stable analogue of prostacycline, currently employed in the treatment of SSc vascular features, also possess anti-oxidative properties beside its prostaglandin-like vasodilatory and antiaggregant effects. This brief review is aimed to discuss available clinical evidences supporting Iloprost antioxidant action and focus on putative molecular pathways underlying it.

Effect of rituximab on clinical and laboratory features of antiphospholipid syndrome: a case report and a review of literature.

Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by a hypercoagulable state related to persistently elevated levels of antiphospholipid antibodies (aPL). Current treatment for APS is only partially effective and new therapies are strongly needed. We report on a case of a 50 years old man with APS who suffered from recurrent thromboembolic episodes despite conventional anticoagulant treatment. Eight years after the first thrombotic manifestation he was diagnosed with a large B cell non-Hodgkin lymphoma. Treatment with CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) plus rituximab was started with partial clinical remission of lymphoma and normalization of aPL levels with a three years follow-up period free of thrombotic episodes.A review of the literature revealed that only 12 case reports on the use of rituximab in patients with primary, secondary and catastrophic APS have been published. Current knowledge clearly suggests the need for clinical trials to evaluate the effect of rituximab in the treatment of resistant APS.

Iloprost therapy acutely decreases oxidative stress in patients affected by systemic sclerosis.

BACKGROUND: Oxidative stress has been considered a leading factor in the pathogenesis of systemic sclerosis (SSc). Consistently with this hypothesis the determination of urinary isoprostanes, a reliable method for evaluation of oxidative stress, has recently showed increased levels of isoprostanes in SSc patients. Data about the effect on oxidative stress of accepted therapies for SSc such as iloprost therapy are lacking. OBJECTIVE: The aim of this prospective study was to verify whether iloprost therapy in patients with SSc acutely reduces oxidative stress assessed by determination of 8-Iso PGF2alpha urinary levels. METHODS: urine samples were obtained before and after a five-day cycle of iloprost infusion and urinary 8-Iso PGF2alpha levels were determined using a commercially available enzyme immunoassay. RESULTS: Consistent with previous reports, we found an increased level of oxidative stress in SSc patients with respect to healthy controls. Basal urinary 8-iso PGF2alpha levels in SSc patients were significantly higher than those in healthy controls [2002(1122-3575) pg/mg creatinine vs. 334(225.7-441) pg/mg creatinine, p<0.001]. Moreover, as expected, urinary 8-iso PGF2alpha levels after iloprost therapy were significantly lower than basal levels [1277.5 pg/mg creatinine (742.7-2017.3) vs. 2002 pg/mg creatinine (1122-3575), p=0.001] but persisted significantly elevated respect to the levels of healthy controls (p<0.001). The effect of iloprost on oxidative stress appeared significant in patients with early and limited form of disease. CONCLUSIONS: This prospective open-label explorative study suggests that standard course of iloprost therapy may acutely reduce oxidative stress in SSc patients. This effect appears to be more consistent in the early phases and in the limited subset of disease. Further larger trials are needed to confirm our results and to explain the pathway of such reduction, its clinical significance and potential therapeutic implications.

[Diagnostic and prognostic value of antibodies to cyclic citrullinated peptide (Anti-CCP) in rheumatoid arthritis]. / Il significato diagnostico e prognostico degli anticorpi anti-peptide citrullinato ciclico (Anti-CCP) nell'artrite reumatoide.

There is strong evidence that the determination of autoantibodies against filaggrine is a very useful tool for the diagnosis of rheumatoid arthritis (RA). Anti-cyclic citrullinated peptide antibodies (Anti-CCP)-ELISA appear to be the most efficient test among those available for the detection of antifilaggrine autoantibodies, as it has the best diagnostic accuracy for the diagnosis of RA. Furthermore, the anti-CCP-ELISA determination in early arthritis is a good predictor of disease persistence and radiographic joint damage. The positivity of Anti-CCP some years before the onset of the RA and the high concentration of autoantibodies in synovial fluid suggest a possible pathogenetic role of citrullination. However, at present, it is unclear whether anti-CCP antibodies have a better diagnostic performance than rheumatoid factor in recent onset synovitis and if they confer any additional value to the prognostic evaluation obtained with validated predictors of outcome (FR, joint count, duration of disease).

Genetic and antigenic characterization of caev (caprine arthritis-encephalitis virus) recombinant transmembrane protein.

The env gene fragment of an Italian strain of Caprine Arthritis Encephalitis virus (CAEV) coding for the hydrophilic region of transmembrane protein was amplified, cloned and expressed in prokaryotic system as fusion protein with glutathione-S-transferase. Sequence analysis revealed 63 to 66% amino acid homology, when compared with three ovine lentiviruses and 83% when compared with one caprine lentivirus. The recombinant transmembrane protein was efficiently expressed, purified under denaturing conditions and used as antigen in western blotting and ELISA. Sera from clinically diseased goats strongly reacted in western blotting and naturally infected animals seroconverted between 20 and 33 weeks of age. An indirect ELISA performed with this antigen showed improved sensitivity in comparison with agar gel immunodiffusion test. Our results confirm that transmembrane protein is an important immunological marker in CAEV infection and its use as antigen may enhance the validity of serological diagnosis of Caprine Arthritis Encephalitis.

Sequence of cDNA coding for a 65 kDa adhesive protein for the specific detection of Trichomonas vaginalis by PCR.

A Trichomonas vaginalis cDNA library was constructed and recombinant plaques were screened using rabbit immunoglobulins specific for P65, a protozoan protein involved in pathogenicity that we identified in a previous study. A 1.38 kilobases cDNA fragment coding for the P65 protein was cloned in E. coli and then sequenced. On the basis of of the sequence obtained, six primers were synthesised and used to set up a Polymerase Chain Reaction. The presence of a specific amplicon in all 30 clinical isolates tested shows that P65 is a conserved and stable gene. The reaction is highly sensitive (as few as 5 to 10 parasites can be detected) and specific for Trichomonas vaginalis; the gene coding P65 adhesin can be therefore considered a very good molecular target for polymerase chain reaction-based diagnostic purposes.

TnphoA Salmonella abortusovis mutants unable to adhere to epithelial cells and with reduced virulence in mice.

Salmonella abortusovis is a pathogenic bacterium highly specific to sheep, causing spontaneous abortion. In order to understand the role of genes involved in pathogenicity, we investigated S. abortusovis with the random mutagenic TnphoA transposon. A total of 95 S. abortusovis TnphoA mutants yielding alkaline phosphatase active fusion protein were obtained. In this way we created a bank of strains in order to identify any phenotypic modification which could affect the periplasmic and/or exported proteins involved in virulence. The TnphoA mutants were screened for the ability to adhere to epithelial cells: a total of 23 mutant strains lost this phenotypic feature. To detect the chromosomal TnphoA insertions, DNA was restricted by the enzyme EcoRV, which does not cleave the TnphoA sequence. Southern blotting analysis revealed the existence of four classes of integration. Colonies of adhesiveless mutants appear to be as smooth as the S. abortusovis wild type, and electrophoretic analysis indicates a normal lipopolysaccharide profile. To identify mutations affecting genes encoding for outer membrane proteins (OMPs), the alkaline phosphatase portion of the fusion proteins was revealed in TnphoA mutants by immunoblotting with specific antibodies. A mutation in OMPs was detected in seven mutants. Restriction analysis identified in four mutants a common region of 2 kb where alterations in genes coding for OMPs occur. We suggested that this region is involved in pathogenicity in mice, since a group of mutant strains has shown reduced virulence in mice and one mutant is completely avirulent. Furthermore, after mice were exposed orally to these mutants, significant protection against oral challenge with the parental virulent strain resulted.

Molecular probe for identification of Trichomonas vaginalis DNA.

Trichomoniasis is one of the most widespread sexually transmitted diseases in the world. Diagnosis can be achieved by several methods, such as direct microscopic observation of vaginal discharge, cell culture, and immunological techniques. A 2.3-kb Trichomonas vaginalis DNA fragment present in strains from diverse geographic areas was cloned and used as a probe to detect T. vaginalis DNA in vaginal discharge by a dot blot hybridization technique. This probe was specific for T. vaginalis DNA. It recognized strains from two regions in Italy (Sardinia, Piemonte) and from Mozambique (Africa). In addition, our probe did not cross-react with bacterial (Escherichia coli, Enterococcus spp., group B streptococci, Gardnerella vaginalis, Neisseria gonorrhoeae, Chlamydia trachomatis, and Lactobacillus spp.), viral (herpes simplex virus type 2), fungal (Candida albicans), protozoan (Entamoeba histolytica, Giardia lamblia, Plasmodium falciparum, Leishmania major, and Leishmania infantum), or human nucleic acids. The probe reacted with Pentatrichomonas hominis and Trichomonas foetus. The limit signal recognized by our probe corresponded to the DNA of 200 T. vaginalis isolates. The 2.3-kb probe was used in a clinical analysis of 98 samples. Of these, 20 samples were found to be positive both with the probe and by cell culture, and only 14 of these were positive by a standard wet mount method.