Mirko Scarsi

Type I interferons in systemic autoimmunity.

Type I IFN (IFN-I) was firstly described in 1957 as a soluble factor responsible for viral resistance in vitro. Today, it is well known that the IFN-I family comprises a wide number of cytokines with different modulatory effects on angiogenesis, cell growth, fibrosis, and apoptosis. However, one of the most important functions of IFN-I is the capability to trigger a complex array of cellular responses that result in a host-protective antiviral response. For this reason, IFN-I can be considered a “director” of protective immune responses. The recent finding of the so-called interferon signature in patients suffering from different autoimmune diseases has underlined its possible role in the pathogenesis of these diseases. On the other hand, IFN-α/β is reported to be efficacious in the treatment of some autoimmune and infectious diseases not responsive to conventional therapy. On these occasions, the treated patients often start or increase autoantibody production supporting the role of IFN as inducer of an autoimmune response. In this review, we will underline recent acquisitions about IFN-I biology, with a focus on the relevance of the induction of some autoimmune diseases, such as systemic lupus erythematosus, systemic sclerosis, rheumatoid arthritis, dermato/polymiositis, and Sjogrens syndrome.

Use of Tumor Necrosis Factor-α-blocking Agents in Hepatitis B Virus-positive Patients: Reports of 3 Cases and Review of the Literature

Objective. To evaluate the development of hepatitis B virus (HBV) infection in patients receiving tumor necrosis factor-α-blocking agents (TNFBA), and to evaluate whether lamivudine (LAM) prophylaxis can reduce the risk of viral reactivation in inactive HBsAg carriers. Methods. Local experience and published reports were reviewed. Patients with HBV infection were classified as having chronic HBV hepatitis, or being inactive HBsAg carriers or occult carriers. Results. Three patients in our series and 24 patients in the literature were identified: 2 had active HBV-associated disease, 23 were inactive HBsAg carriers, and 2 occult carriers. When exposed to TNFBA, HBsAg-inactive carriers pretreated with LAM had lower risk of having detectable HBV-DNA (p = 0.02) or viral reactivation (p = 0.046) than those without LAM prophylaxis. In 3 patients who discontinued TNFBA, LAM prophylaxis was also discontinued 10–12 months thereafter without hepatitis flares. Two cases of reactivation in occult carriers (HBsAg-negative, anti-HBs+, anti-HBc+) were described in the literature. Conclusion. TNFBA should be avoided in patients with active HBV replication and should be used with caution in inactive HBsAg carriers. In these patients, the risk of viral reactivation seems to be high, but it might be reduced by prophylactic LAM, which should probably be given for a long time when TNFBA are discontinued (e.g., 12 mo). Potential occult carriers might carry a low, but not negligible, risk of viral reactivation. They should therefore be monitored with particular care.

Baseline Numbers of Circulating CD28-negative T Cells May Predict Clinical Response to Abatacept in Patients with Rheumatoid Arthritis

Objective. To evaluate the number of circulating CD28-negative (CD28–) T cells as a predictor of clinical response to abatacept in patients with rheumatoid arthritis (RA). Methods. Peripheral blood CD28– T cell subsets were evaluated by flow cytometry at baseline in 32 patients with RA treated with abatacept. Receiver-operator curves were applied to examine the predictive value of T cell populations and to choose the cutoff for the best performance of the test. Remission was defined using the Disease Activity Score 28 based on C-reactive protein. Results. The overall predictive values of the CD8+CD28– and CD4+CD28– cells for remission after 6 months of abatacept therapy were 0.802 (SE 0.078) and 0.743 (SE 0.089), respectively. Cutoff values of < 87 CD8+CD28– cells/μl and < 28 CD4+CD28– cells/μl had 80.0% sensitivity and 81.8% specificity (Fisher test: p = 0.001), and 60.0% sensitivity and 77.3% specificity (p = 0.043), respectively, for prediction of remission at 6 months. Patients having low baseline numbers of CD8+CD28– T cells had a more than 4-fold higher probability of achieving remission within 6 months than patients with higher levels of these cells. Conclusion. A simple laboratory measure, the baseline number of circulating CD28– T cells, predicted remission after 6 months of abatacept treatment in patients with RA.

Decreased Circulating CD28-negative T Cells in Patients with Rheumatoid Arthritis Treated with Abatacept Are Correlated with Clinical Response

Objective. To verify the hypothesis that blockade of CD28 costimulation by treatment with abatacept in patients with rheumatoid arthritis (RA) might induce a reduction in the number of CD28– T cells, as well as other effector T cell populations. We evaluated whether these variations correlate with clinical response. Methods. Peripheral blood T cell subsets were longitudinally evaluated by flow cytometry through the analysis of CD28, CD45RA, and CCR7 expression in 16 patients with RA who were treated with abatacept. Results. After 48 weeks of treatment, the proportion and the absolute number of circulating CD8+CD28– T cells decreased (p = 0.008, p = 0.055, respectively, compared with baseline), as well as the proportion of the CD8+CD45RA+CCR7– cells, thought to represent terminally differentiated effector T cells (p = 0.03). Reductions of percentages of circulating CD4+CD28– and CD8+CD28– T cells, and (CCR7–) CD8+ total effector T cells were directly correlated with the reduction of Disease Activity Score 28 C-reactive protein (r = 0.58, p = 0.014; r = 0.47, p = 0.059; r = 0.59, p = 0.012, respectively). Conclusion. After therapy with abatacept, circulating CD28– T cells and other effector populations decrease in patients with RA. This decrease is correlated with clinical response.

Prevalence and clinical associations of anti-Ku antibodies in systemic autoimmune diseases

We retrospectively analysed the prevalence and clinical features associated to anti-Ku antibodies in patients affected by different autoimmune diseases. Anti-Ku antibodies are detected in 147 sera out of 7239 anti-ENA positive sera (2%). They are found in 2% of patients with systemic sclerosis (SSc) (8 out of 379), 1.8% of systemic lupus erythematosus (SLE) (7 out of 372) and 1.8% of undifferentiated connective tissue disease (UCTD) (9 out of 496) and more rarely in Sjögren Syndrome and rheumatoid arthritis. Most of anti-Ku positive patients were affected by UCTD and overlap syndromes, including polymyositis, SSc and SLE. Interstitial lung disease, myositis, articular symptoms, Raynaud’s phenomenon and sicca represents the main clinical features detected in our cohort. The rate and severity of pulmonary disease is similar to those found in other SSc patients. Isolated anti-Ku were detected in about 47% of sera. No clinical differences were observed between these patients and subjects with multiple anti-nuclear specificities. However, anti-Ku are usually detected in association with other serological markers in SLE and Sjögren Syndrome, while they occurred isolated in SSc and polymyositis.

Abatacept Reduces Levels of Switched Memory B Cells, Autoantibodies, and Immunoglobulins in Patients with Rheumatoid Arthritis

Objective. Abatacept (ABA) is a chimeric molecule, able to block the CD28-mediated costimulatory pathway. To evaluate the hypothesis that, through this mechanism of action, ABA may down-modulate the immune responses of B lymphocytes in rheumatoid arthritis (RA), we investigated the serum levels of immunoglobulins (Ig), free light chains (FLC), anticitrullinated protein antibodies (ACPA), and rheumatoid factor (RF), as well as the number of B lymphocytes differentiated into post-switch memory cells in patients treated with ABA. Methods. The serum levels of Ig, FLC, different ACPA, RF isotypes, and the B cell phenotype were longitudinally evaluated in 30 patients with RA treated with ABA. Results. At baseline, the proportion of total and post-switch memory B cells was lower in RA than in healthy individuals. After 6 months of ABA treatment we observed significant reductions of serum levels of IgG, IgA, and IgM, as well as FLC, with a normalization in many patients who had initially abnormal values. A significant reduction of the titers of IgG- and IgA-ACPA, as well as of IgM-, IgA-, and IgG-RF was also observed. A decrease of autoantibodies below the upper limits of normal values was found in 2 of 26 patients (8%) initially seropositive for IgG-ACPA, 1 of 14 (7%) for IgA-ACPA, 5 of 22 (23%) for IgM-RF, 7 of 22 (30%) for IgA-RF, and 5 of 16 (31%) for IgG-RF. After treatment, the proportion of circulating post-switch memory B cells was also further significantly decreased. Conclusion. ABA treatment in patients with RA can reduce signs of polyclonal B cell activation, inducing a trend toward normalization of serum levels of different classes of Ig and of FLC, decreasing titers of ACPA and RF, and percentages of post-switch memory B cells.

Impact of in utero environment on the offspring of lupus patients

The number of patients affected by systemic lupus erythematosus (SLE) that decide to have children has greatly increased probably because of recent improvements in the diagnosis and management of the disease. This has stimulated our interest in defining the outcome of children, focusing both on neonatal problems and long term development. SLE patients still carry a risk of pregnancy loss. However, due to careful monitoring and treatment by a multidisciplinary team, the number of losses has dramatically decreased, but an increased number of preterm deliveries is still a problem. Neonatal lupus is linked to the presence of anti-Ro/SS-A and anti-La/SS-B antibodies in the mother, although other factors probably of fetal origin are important. Neonatal lupus is a complex condition whose most serious manifestation is the congenital heart block (CHB). Usually, children with complete CHB need permanent pacing, but apparently do not have neuropsychological problems. Studies focusing on the neuropsychological development of SLE offspring show an increased number of learning disabilities in children with normal intelligence levels. Fetal consequence of maternal treatment need to be considered choosing non teratogenic drugs, but the withdrawal of medications just because the patient is pregnant should be avoided to avoid SLE flares.

European attempts for the standardisation of the antiphospholipid antibodies

According to the Sydney criteria, antiphospholipid syndrome (APS) diagnosis is closely related to the demonstration of antiphospholipid antibodies (aPL) in patients sera. For this purpose, three different assays are conventionally accepted: lupus anticoagulant (LA), anticardiolipin (aCL) and anti-β2 glycoprotein I (β2GPI) antibodies. LA, described in the 1950s is a coagulation-based functional assay, which indirectly detects the presence of aPL. The aCL ELISA was developed in 1985; the identification of β2GPI as a major target of aPL, allowed the introduction of anti-β2GPI ELISA. Even if the diagnostic criteria for APS have been well defined, the laboratory detection of aPL is not always reproducible for many reasons. To achieve a univocal diagnostic definition of APS, efforts were made to reduce the inter- and/or intra-laboratory variability of the diagnostic tests. In this article, we analyse the studies performed to standardise aPL assays that were developed within the European Forum on Antiphospholipid Antibodies.

Thymic and Bone Marrow Output in Patients with Common Variable Immunodeficiency

ObjectiveThe study aims to obtain more information about the immune deficit of common variable immunodeficiency (CVID) patients.Materials and MethodsA new real-time PCR assay was used to quantify T and B lymphocyte mobilization from the production and maturation sites through the detection of T cell receptor excision circles (TRECs) and kappa-deleting recombination circles (KRECs) and to allow the estimation of the average number of B cell divisions. T and B lymphocyte subsets were analyzed by flow cytometry.ResultsThe number of TREC+ lymphocytes, which depends on age and gender, was significantly reduced in CVID patients. Similarly, KREC concentration was lower than in controls. Classification of patients according to the percentage of memory switched B cells showed that patients belonging to MB2 group and therefore with conserved B cell maturation have the lowest new B cell output but increased average peripheral divisions, leading to the highest B cell number.ConclusionsTREC and KREC quantification can be helpful for a more complete and informative understanding of a heterogeneous disease such as CVID.

Detection of anti-IFI16 antibodies by ELISA: clinical and serological associations in systemic sclerosis

OBJECTIVES To validate the clinical significance of anti-IFI16 autoantibodies in SSc and assess their associations with serological markers of SSc. METHODS A semi-quantitative ELISA was used to detect anti-IFI16 autoantibodies in the sera of 344 SSc patients from seven Italian hospitals and 144 healthy controls. SSc-associated autoantibodies [anti-RNA polymerase III (anti-RNAP III) antibodies, anti-centromere, anti-topo I] and IF patterns were evaluated using commercial assays. Statistical analyses were performed to test clinical and serological associations. RESULTS The results of this study confirm a significant prevalence (29%) of anti-IFI16 antibodies in the SSc population (n = 344). Anti-IFI16 antibodies were also detected in 30% of the SSc patients who tested negative for both ACAs and anti-topo I (anti-Scl70) antibodies. In this subgroup of patients, anti-IFI16 antibodies were significantly associated with the limited cutaneous form of SSc with a sensitivity of 40% and a specificity of 81%. Moreover, analysis of the distribution of anti-RNAP III antibodies vs anti-IFI16 in the same SSc population showed that they were mutually exclusive. IIF revealed no association between anti-IFI16 and fluoroscopic patterns, due to a lack of IFI16 autoantigen in HEp-2 cells. Anti-IFI16 antibody levels were also significantly associated with heart involvement. CONCLUSIONS Anti-IFI16 autoantibodies are frequently detected in SSc, displaying clinical and laboratory associations, and being particularly useful for diagnosis and disease classification in patients who are negative for other SSc serological markers.