Adrian Ciurea

Hypergammaglobulinemia and autoantibody induction mechanisms in viral infections

Polyclonal hypergammaglobulinemia is a characteristic of chronic inflammatory conditions, including persisting viral infections and autoimmune diseases. Here we have studied hypergammaglobulinemia in mice infected with lymphocytic choriomeningitis virus (LCMV), which induces nonspecific immunoglobulins as a result of switching natural IgM specificities to IgG. The process is dependent on help from CD4+ T cells that specifically recognize LCMV peptides presented by B cells on major histocompatibility complex class II molecules. Thus, hypergammaglobulinemia may arise when specific helper T cells recognize B cells that have processed viral antigens irrespective of the B cell receptor specificity. This nonspecific B cell activation may contribute to antibody-mediated autoimmunity.

Comparison of drug retention rates and causes of drug discontinuation between anti–tumor necrosis factor agents in rheumatoid arthritis

OBJECTIVE Tumor necrosis factor (TNF) inhibitors have revolutionized the treatment of severe rheumatoid arthritis (RA), yet drug discontinuation is common. The aim of this study was to compare treatment retention rates and specific causes of anti-TNF discontinuation in a population-based RA cohort. METHODS All patients treated with etanercept, infliximab, or adalimumab within the Swiss Clinical Quality Management RA cohort between 1997 and 2006 were included in the study. Causes of treatment discontinuation were broadly categorized as adverse events (AEs) or nontoxic causes, and further subdivided into specific categories. Specific causes of treatment interruption were analyzed using a Cox proportional hazards model and adjusted for potential confounders. RESULTS A total of 2,364 anti-TNF treatment courses met the inclusion criteria. Treatment discontinuation was reported 803 times: 309 with etanercept, 249 with infliximab, and 245 with adalimumab. Drug inefficacy represented the largest single cause of treatment discontinuation (55.8% of cases). The median time of receiving anti-TNF therapy was 37 months, but discontinuation rates differed between the 3 anti-TNF agents (P < 0.001), with shorter retention rates for infliximab (hazard ratio [HR] 1.24, 99% confidence interval [99% CI] 1.01-1.51). The specific causes of treatment discontinuation revealed an increased risk of AEs with infliximab (HR 1.4, 99% CI 1.003-1.96), mostly due to an increased risk of infusion or allergic reactions (HR 2.11, 99% CI 1.23-3.62). Other discontinuation causes were equally distributed between the anti-TNF agents. CONCLUSION In this population, infliximab was associated with higher overall discontinuation rates compared with etanercept and adalimumab, which is mainly due to an increased risk of infusion or allergic reactions.

2016 update of the ASAS-EULAR management recommendations for axial spondyloarthritis

To update and integrate the recommendations for ankylosing spondylitis and the recommendations for the use of tumour necrosis factor inhibitors (TNFi) in axial spondyloarthritis (axSpA) into one set applicable to the full spectrum of patients with axSpA. Following the latest version of the European League Against Rheumatism (EULAR) Standardised Operating Procedures, two systematic literature reviews first collected the evidence regarding all treatment options (pharmacological and non-pharmacological) that were published since 2009. After a discussion of the results in the steering group and presentation to the task force, overarching principles and recommendations were formulated, and consensus was obtained by informal voting. A total of 5 overarching principles and 13 recommendations were agreed on. The first three recommendations deal with personalised medicine including treatment target and monitoring. Recommendation 4 covers non-pharmacological management. Recommendation 5 describes the central role of non-steroidal anti-inflammatory drugs (NSAIDs) as first-choice drug treatment. Recommendations 6–8 define the rather modest role of analgesics, and disprove glucocorticoids and conventional synthetic disease-modifying antirheumatic drugs (DMARDs) for axSpA patents with predominant axial involvement. Recommendation 9 refers to biological DMARDs (bDMARDs) including TNFi and IL-17 inhibitors (IL-17i) for patients with high disease activity despite the use (or intolerance/contraindication) of at least two NSAIDs. In addition, they should either have an elevated C reactive protein and/or definite inflammation on MRI and/or radiographic evidence of sacroiliitis. Current practice is to start with a TNFi. Switching to another TNFi or an IL-17i is recommended in case TNFi fails (recommendation 10). Tapering, but not stopping a bDMARD, can be considered in patients in sustained remission (recommendation 11). The final two recommendations (12, 13) deal with surgery and spinal fractures. The 2016 Assessment of SpondyloArthritis international Society-EULAR recommendations provide up-to-date guidance on the management of patients with axSpA.

Neutralizing antiviral antibody responses.

Publisher Summary Neutralizing antibodies are evolutionarily important effectors of immunity against viruses. Their evaluation has revealed a number of basic insights into specificity, rules of reactivity (tolerance), and memory—namely, (1) Specificity of neutralizing antibodies is defined by their capacity to distinguish between virus serotypes; (2) B cell reactivity is determined by antigen structure, concentration, and time of availability in secondary lymphoid organs; and (3) B cell memory is provided by elevated protective antibody titers in serum that are depending on antigen stimulation. These perhaps slightly overstated rules are simple, correlate with in vivo evidence as well as clinical observations, and appear to largely demystify many speculations about antibodies and B cell physiology. The chapter also considers successful vaccines and compares them with those infectious diseases where efficient protective vaccines are lacking, it is striking to note that all successful vaccines induce high levels of neutralizing antibodies (nAbs) that are both necessary and sufficient to protect the host from disease. Successful vaccination against infectious diseases such as tuberculosis, leprosy, or HIV would require induction of additional long-lasting T cell responses to control infection.

Correlation of T cell independence of antibody responses with antigen dose reaching secondary lymphoid organs: implications for splenectomized patients and vaccine design.

Many natural viral and bacterial pathogens activate B cells independently of Th cells (TI Ags). This study analyzed the characteristics of the activation of B cells after immunization with various forms of viral Ags using different immunization routes and found a decreasing dependence on T help with increasing amounts of Ag recruited to the spleen. Repetitive antigenic structure facilitated TI B cell responses if Ag was present in lymphoid organs. These results suggest that 1) Ag dose and localization in secondary lymphoid organs are the key for B cell activation in the absence of T help; 2) early TI Ab responses are crucial to protect against systemically spreading acute cytopathic infectious agents; and 3) there may be new rationales for improved vaccine design.

Tumor Necrosis Factor α Inhibition in Radiographic and Nonradiographic Axial Spondyloarthritis: Results From a Large Observational Cohort

OBJECTIVE To evaluate the baseline characteristics of patients with radiographic axial spondyloarthritis (SpA; ankylosing spondylitis [AS]) and patients with nonradiographic axial SpA, to investigate determinants of anti-tumor necrosis factor (anti-TNF) agent prescription on the background of a nonrestrictive reimbursement policy, and to assess the response to TNF inhibition. METHODS We compared the characteristics of radiographic axial SpA and nonradiographic axial SpA in 1,070 patients from the Swiss Clinical Quality Management (SCQM) Cohort who fulfilled the Assessment of SpondyloArthritis international Society (ASAS) classification criteria for axial SpA. By taking advantage of the situation that patients who are eligible for anti-TNF treatment are preferentially enrolled in the SCQM Cohort for patients with AS/axial SpA, we explored parameters leading to the initiation of anti-TNF treatment in single and multiple regression models and assessed treatment responses. RESULTS We confirmed a similar burden of disease (as determined by self-reported disease activity, impaired function, and quality of life) in patients with nonradiographic axial SpA (n = 232) and those with radiographic axial SpA (n = 838). Patients with radiographic axial SpA had higher median levels of acute-phase reactants and higher median AS Disease Activity Scores (ASDAS; 3.2 versus 3.0). Anti-TNF treatment was initiated in 363 patients with radiographic axial SpA and 102 patients with nonradiographic axial SpA, preferentially in those with sacroiliitis on magnetic resonance imaging, peripheral arthritis, a higher C-reactive protein (CRP) level, a higher ASDAS, and a higher Bath Ankylosing Spondylitis Disease Activity Index level. The ASAS criteria for 40% improvement responses at 1 year were higher in patients with radiographic axial SpA compared with those with nonradiographic axial SpA (48.1% versus 29.6%; odds ratio [OR] 2.2, 95% confidence interval [95% CI] 1.12-4.46, P = 0.02). The difference was smaller in the subgroups of patients with elevated baseline CRP levels (51.6% in patients with radiographic axial SpA versus 38.5% in those with nonradiographic axial SpA; OR 1.7, 95% CI 0.68-4.48, P = 0.29). CONCLUSION The indications for treatment with anti-TNF agents were comparable for patients with radiographic axial SpA and those with nonradiographic axial SpA. With the exception of patients with elevated CRP levels at baseline, higher rates of response to TNF inhibition were achieved in the group of patients with radiographic axial SpA than in the group with nonradiographic axial SpA.

CD4+ T-cell-epitope escape mutant virus selected in vivo.

Mutations in viral genomes that affect T-cell–receptor recognition by CD8+ cytotoxic T lymphocytes have been shown to allow viral evasion from immune surveillance during persistent viral infections. Although CD4+ T-helper cells are crucially involved in the maintenance of effective cytotoxic T-lymphocyte and neutralizing-antibody responses, their role in viral clearance and therefore in imposing similar selective pressures on the virus is unclear. We show here that transgenic virus-specific CD4+ Tcells, transferred into mice persistently infected with lymphocytic choriomeningitis virus, select for T-helper epitope mutant viruses that are not recognized. Together with the observed antigenic variation of the same T-helper epitope during polyclonal CD4+ T-cell responses in infected pore-forming protein-deficient C57BL/6 mice, this finding indicates that viral escape from CD4+ T lymphocytes is a possible mechanism of virus persistence.

Delays in assessment of patients with rheumatoid arthritis: variations across Europe

Objective The first 3 months after symptom onset represent an important therapeutic window for rheumatoid arthritis (RA). This study investigates the extent and causes of delay in assessment of patients with RA in eight European countries. Method Data on the following levels of delay were collected from 10 centres (Berlin, Birmingham, Heraklion, Lund, Prague, Stockholm, Umeå, Vienna, Warsaw and Zurich): (1) from onset of RA symptoms to request to see healthcare professional (HCP); (2) from request to see HCP to assessment by that HCP; (3) from initial assessment by HCP to referral to rheumatologist; and (4) from referral to rheumatologist to assessment by that rheumatologist. Results Data were collected from 482 patients with RA. The median delay across the 10 centres from symptom onset to assessment by the rheumatologist was 24 weeks, with the percentage of patients seen within 12 weeks of symptom onset ranging from 8% to 42%. There were important differences in the levels underlying the total delays at individual centres. Conclusions This research highlights the contribution of patients, professionals and health systems to treatment delay for patients with RA in Europe. Although some centres have strengths in minimising certain types of delay, interventions are required in all centres to ensure timely treatment for patients.

18F-Fluoride PET/CT for detection of sacroiliitis in ankylosing spondylitis

PurposeThe aim of this study was to evaluate the performance of 18F-fluoride-PET/CT (PET/CT) for the diagnosis of sacroiliac joint (SIJ) arthritis in patients with active ankylosing spondylitis (AS).MethodsIncluded in the study were 15 patients with AS according to the modified New York criteria (AS group) and with active disease and 13 patients with mechanical low back pain (MLBP; control group) who were investigated with whole-body 18F-fluoride PET/CT. The ratio of the uptake in the SIJ and that in the sacrum (SIJ/S) was calculated for every joint.ResultsThe mean SIJ/S ratio of 30 quantified joints in the AS group was 1.66 (range 1.10–3.07) with PET/CT, and the mean SIJ/S ratio of 26 quantified joints in the MLBP group was 1.12 (range 0.71–1.52). The area under the receiver operating characteristic curve for SIJ arthritis was 0.84. With plain radiography as a the gold standard and taking an SIJ/S ratio of >1.3 as the threshold, the sensitivity, specificity and accuracy on a per patient basis were 80%, 77% and 79%, respectively. On a per SIJ basis, the greatest sensitivity (94%) was found in grade 3 sacroiliitis (n = 16).ConclusionOur results suggest that quantitative 18F-fluoride PET/CT may play a role in the diagnosis of sacroiliitis in active AS and is an alternative to conventional bone scintigraphy in times of molybdenum shortage.

Influence of anti-infliximab antibodies and residual infliximab concentrations on the occurrence of acquired drug resistance to infliximab in rheumatoid arthritis patients

BACKGROUND Infliximab (IFX) can be immunogenic for humans and lead to the formation of antibodies against IFX (anti-IFX Ab), which could induce acquired IFX resistance. OBJECTIVE To test whether the presence of anti-IFX Ab and residual circulating IFX levels are associated with acquired IFX resistance in RA. METHODS A multivariate logistic regression was used to analyze the relationship between anti-IFX Ab, residual IFX concentrations, and acquired IFX resistance in a nested cohort within the Swiss RA registry (SCQM-RA). RESULTS Sixty-four RA patients on longstanding IFX therapy were included; 24 with an acquired therapeutic resistance to IFX and 40 with continuous good response to IFX. The two groups had similar disease characteristics, but patients with acquired IFX resistance required significantly higher dosage of IFX (5.4 mg/kg versus 4.3 mg/kg, p=0.02) and shorter infusion intervals (7.1 versus 8.7 weeks, p=0.01) than long-term good responders. The presence of residual IFX tended to be associated with a decreased risk of acquired therapeutic resistance (OR 0.4 [95% CI: 0.1-1.5]), while the presence of anti-IFX Ab tended to be associated with an increased risk of acquired therapeutic resistance (OR: 1.8 [95% CI: 0.4 - 9.0]). The presence of either high anti-IFX Ab levels or low residual IFX concentrations was strongly associated with acquired therapeutic resistance to IFX (OR 5.9, 95% CI 1.3 - 26.6). However, just 42% of patients with acquired IFX resistance had either low IFX or high anti-IFX Ab levels. CONCLUSION These results suggest that the assessment of anti-IFX Ab and residual IFX levels is of limited value for individual patients in routine clinical care.