Antibodies against citrullinated proteins of IgA isotype are associated with progression to rheumatoid arthritis in individuals at-risk

OBJECTIVE

Events triggering disease outbreak in individuals at-risk for rheumatoid arthritis (RA at-risk) remain unclear, and the role of the various anticitrullinated protein antibody (ACPA) isotypes in this process is still to be established. We aimed to investigate the prevalence of IgA ACPA in RA at-risk individuals, their role in the transition from the RA at-risk status to RA and their dynamics during this transition.

METHODS

Cross-sectional measurement of serum IgA1 and IgA2 ACPA levels was conducted in healthy controls, RA at-risk individuals and patients with RA and compared with the frequency of RA development in at risk individuals during a follow-up of 14 months. In addition, longitudinal measurements of serum IgA1 and IgA2 ACPA levels prior to, at and after the onset of RA were performed.

RESULTS

Approximately two-thirds of RA at-risk individuals were positive for serum IgA1 and IgA2 ACPA in levels comparable to IgG ACPA positive patients with RA. IgA1, but not IgA2 ACPA positivity was associated with the transition from the RA at-risk state to RA within the following 14 months. Interestingly, during this transition process, IgA1 ACPA levels declined at RA onset and also thereafter during the early phase of RA. This decline was confirmed in a second, independent cohort.

CONCLUSION

Both IgA1 and IgA2 ACPA are present in RA at-risk individuals, but only IgA1 ACPA are associated with the progression to RA. The observed decline in serum IgA1 ACPA levels before the onset of RA might indicate starting barrier leakiness prior to disease outbreak.

Levilimab and baricitinib prescribing experience in outpatient COVID-19 patients’ treatment

Aim. To study the effect of levilimab or baricitinib in combination with standard therapy (ST) on the incidence of severe viral pneumonia associated with a new coronavirus infection COVID-19. Materials and methods. A multicenter, open-label observational study of the efficacy and safety of levilimab in combination with ST (group 1, n=100), baricitinib in combination with ST (group 2, n=139), or in comparison with ST (group 3, n=200) in outpatients with verified CT-1 pneumonia. Results. According to the results of laboratory tests, patients treated with levilimab in combination with ST had the best dynamics of changes in CRP from reliably the highest level (mg/L) to the lowest in comparison with other groups. In the group of patients with ST, in contrast to the other groups, no dynamics of CRP was observed by day 5 of therapy. In group of hospitalized patients initially receiving levilimab in addition to ST, the rate of transfer to the intensive care unit (2 patients, 9.52%) and length of stay (4 days) was significantly lower compared to the values in patients in both the baricitinib group in combination with ST (7 patients, 15.56%; 5 days [interquartile range 36.5]) and in patients receiving ST alone (7 patients, 15.56%; 5 days [interquartile range 36.5]). Also in hospitalized patients we observed no statistically significant intergroup differences in the incidence of infectious complications and thromboembolic events, which confirms the safety of including levilimab or baricitinib in COVID-19 pathogenetic therapy regimens. Observational results support the hypothesis that the initial inclusion of levilimab or baricitinib in addition to ST is accompanied by a reduced risk of viral pneumonia progression. Conclusion. The addition of levilimab or baricitinib to the therapy regimen for coronavirus infection during the outpatient phase has demonstrated a preemptive anti-inflammatory effect and reduced the probability of lung tissue damage progression.

IgA Complexes Induce Neutrophil Extracellular Trap Formation More Potently Than IgG Complexes

Neutrophil extracellular trap (NET) formation is a powerful instrument to fight pathogens, but may induce collateral damage in the affected tissues. Besides pathogen-derived factors, immune complexes are potent inducers of NET formation. Neutrophils express IgA and IgG specific Fc receptors (FcRs) and therefore respond to complexed IgA and IgG. Especially in the context of autoimmune diseases, IgA and IgG immune complexes have been shown to trigger NET formation, a process that putatively contributes to disease severity. However, it is of question if both antibody classes stimulate neutrophils to the same extent. In this study, we compared the capability of IgA and IgG complexes formed by heat aggregation to induce NET formation. While stimulation of neutrophils with IgA complexes robustly induced NET formation, complexed IgG only marginally increased the amount of NETs compared to the unstimulated control. Mixing IgA with IgG before heat aggregation did not increase the effect of complexed IgA on neutrophils. By contrast, the presence of IgG complexes seemed to disturb neutrophil stimulation by IgA complexes. The capacity of complexed IgG to induce NET formation could not be increased by the addition of autologous serum or the removal of terminal sialic acid in the Fc glycan. Together, our data show that IgA is a much more potent inducer of NET formation than IgG. IgA may thus be the main driving force in (auto)immune complex-mediated NET formation.

Recombinant HBsAg of the Wild-Type and the G145R Escape Mutant, included in the New Multivalent Vaccine against Hepatitis B Virus, Dramatically Differ in their Effects on Leukocytes from Healthy Donors In Vitro

Immune-escape hepatitis B virus (HBV) mutants play an important role in HBV spread. Recently, the multivalent vaccine Bubo^®-Unigep has been developed to protect against both wild-type HBV and the most significant G145R mutant. Here, we compared the effects of recombinant HBsAg antigens, wild-type and mutated at G145R, both included in the new vaccine, on activation of a human high-density culture of peripheral blood mononuclear cells (PBMC) in vitro. The antigens were used either alone or in combination with phytohemagglutinin (PHA). None of the antigens alone affected the expression of CD40, HLA-DR or CD279. Wild-type HBsAg enhanced CD86 and CD69 expression, and induced TNF-α, IL-10, and IFN-γ, regardless of the anti-HBsAg status of donor. In the presence of PHA, wild-type HBsAg had no effect on either of the tested surface markers, but increased IFN-γ and IL-10 and inhibited IL-2. In contrast, the G145R mutant alone did not affect CD86 expression, it induced less CD69, and stimulated IL-2 along with lowering levels of TNF-α, IL-10, and IFN-γ. The G145R mutant also suppressed PHA-induced activation of CD69. The dramatic differences in the immune responses elicited by wild-type HBsAg and the G145R mutant HBsAg suggest distinct adaptive capabilities of the G145R mutant HBV.

Autoantibodies in Rheumatoid Arthritis: Historical Background and Novel Findings

Autoantibodies represent a hallmark of rheumatoid arthritis (RA), with the rheumatoid factor (RF) and antibodies against citrullinated proteins (ACPA) being the most acknowledged ones. RA patients who are positive for RF and/or ACPA ("seropositive") in general display a different etiology and disease course compared to so-called "seronegative" patients. Still, the seronegative patient population is very heterogeneous and not well characterized. Due to the identification of new autoantibodies and advancements in the diagnosis of rheumatic diseases in the last years, the group of seronegative patients is constantly shrinking. Aside from antibodies towards various post-translational modifications, recent studies describe autoantibodies targeting some native proteins, further broadening the spectrum of recognized antigens. Next to the detection of new autoantibody groups, much research has been done to answer the question if and how autoantibodies contribute to the pathogenesis of RA. Since autoantibodies can be detected years prior to RA onset, it is a matter of debate whether their presence alone is sufficient to trigger the disease. Nevertheless, there is gathering evidence of direct autoantibody effector functions, such as stimulation of osteoclastogenesis and synovial fibroblast migration in in vitro experiments. In addition, autoantibody positive patients display a worse clinical course and stronger radiographic progression. In this review, we discuss current findings regarding different autoantibody types, the underlying disease-driving mechanisms, the role of Fab and Fc glycosylation and clinical implications.

IgA anti-citrullinated protein antibodies (IgA ACPA) are associated with flares during DMARD tapering in rheumatoid arthritis

OBJECTIVES

A substantial proportion of rheumatoid arthritis (RA) patients flare upon withdrawal of disease modifying anti-rheumatic drugs (DMARDs), thus the definition of prognostic markers is crucial. Anti-citrullinated protein antibody (ACPA)-positivity has been identified as a risk factor for flare. However, only the role of IgG is established in this context, while the role of IgA ACPA is poorly defined. We thus aimed to investigate the role of IgA ACPA in flare of RA.

METHODS

Serum levels of IgA1 and IgA2 ACPA at baseline and after 12 months were measured in 108 patients from the randomized controlled RETRO study. RA patients in stable remission for at least 6 months at study recruitment were assigned to either one of the DMARD tapering arms or to continuation of DMARDs.

RESULTS

In patients remaining in remission but not in the ones who flared, IgA2 ACPA levels and proportion of IgA2 in ACPA (IgA2%ACPA) significantly declined (median of 17.5%; p< 0.0001). This seemed to be independent of the treatment choice, as there was no difference in IgA2 ACPA dynamics between the study arms. IgA2% ACPA was associated with disease activity (DAS28) at flare (r = 0.36; p= 0.046). IgA and IgG ACPA showed a tendency towards independent contribution to the risk of flare with the highest risk if a patient had both antibody classes.

CONCLUSION

In this study, IgA ACPA was identified as a risk factor for flare in combination with IgG ACPA. IgA2 ACPA levels were associated with flare severity and declined in patients in stable remission.

Detection of S-HBsAg Mutations in Patients with Hematologic Malignancies

Multiple studies of hepatitis B virus (HBV) genetic variability and its relationship with the disease pathogenesis are currently ongoing, stemming from growing evidence of the clinical significance of HBV mutations. It is becoming increasingly evident that patients with hematologic malignancies may be particularly prone to a higher frequency of such mutations. The present report is the first extensive study of the prevalence of escape mutations in S-HBsAg, performed using isolates from 59 patients from hospital hematology departments with diagnoses of leukemia (n = 32), lymphoma (n = 20), multiple myeloma (n = 3), and non-tumor blood diseases (n = 4). The isolates were serologically examined for the presence of HBV markers and sequenced using either next-generation sequencing (NGS) or Sanger sequencing. Occult hepatitis B was found in 5.1% of cases. Genetic analysis of the region corresponding to S-HBsAg demonstrated an exceptionally high mutation frequency in patients with leukemias (93.4%) and lymphomas (85.0%), along with the prominent mutation heterogeneity. Additionally, more than 15 mutations in one sample were found in patients with leukemias (6.3% of cases) and lymphomas (5.0% of cases). Most of the mutations were clinically significant. The study analyzes the mutation profile of HBV in different oncohematological diseases and the frequency of individual mutations. The data strongly suggest that the NGS method, capable of detecting minor populations of HBV mutations, provides a diagnostic advantage, lays the foundation for the development of screening methods, and allows for the study of the virological and pathogenetic aspects of hepatitis B.

Apremilast Inhibits Inflammatory Osteoclastogenesis

BACKGROUND

Psoriatic arthritis (PsA) is associated with bone erosion and inflammation-induced bone loss, which are mediated by osteoclasts and modulated by inflammatory cytokines. Apremilast (a selective phosphodiesterase 4 inhibitor) is efficacious in PsA and acts by inhibiting cytokine production. However, there are no direct data informing whether and how apremilast affects osteoclast formation in humans.

METHODS

Osteoclastogenic cytokine production by activated human peripheral blood mononuclear cells (PBMCs) was measured in the presence and absence of apremilast. Effects of apremilast on osteoclast differentiation were tested (i) in co-cultures of activated PBMCs and human CD14+ blood monocytes as well as (ii) in CD14+ blood monocytes stimulated with activated-PBMCs supernatant, TNF or IL-17A. Bone resorption was measured on OsteoAssay plates. Effects of apremilast on ex vivo osteoclast differentiation were compared in PsA, pre-PsA and psoriasis patients as well as in healthy controls.

RESULTS

Apremilast significantly impaired the expression of key osteoclastogenic cytokines in activated PBMCs. Furthermore, apremilast dose-dependently and significantly inhibited activated PBMC-driven osteoclast differentiation, and ex-vivo osteoclast differentiation of PBMCs derived from PsA and pre-PsA patients, but not from psoriasis patients or healthy controls. TNF and IL-17A-enhanced osteoclastogenesis and osteolytic activity of CD14+ blood monocytes from PsA patients was also significantly inhibited by apremilast. Finally, apremilast inhibited expression of the key osteoclast fusion protein DC-STAMP.

CONCLUSION

Phosphodiesterase-4 targeting by apremilast not only inhibits osteoclastogenic cytokine production, but also directly suppresses inflammation-driven osteoclastogenesis. These data provide initial evidence that apremilast has the potential to provide a direct bone protective effect in PsA.

Dynamics of left ventricle myocardial deformation, soluble ST2 and cardiotrophin-1 in hypertensive women on combined valsartan/hydrochlorothiazide therapy

Funding Acknowledgements

Type of funding sources: None.

Background. The treatment-induced regression of left ventricular hypertrophy (LVH) is associated with improved prognosis in patients with arterial hypertension. However, the assessment of LVH by echo is restricted by substantial measurement variability and low sensitivity to changes during follow-up. The alternative approach could be the dynamic evaluation of myocardial deformation parameters and biochemical markers of cardiac remodeling. The purpose of this study was to assess the dynamics of left ventricle (LV) myocardial deformation, soluble ST2 and cardiotrophin-1 levels in hypertensive women treated with combination of valsartan/hydrochlorothiazide.

Methods. The study involved 100 postmenopausal women (mean age – 57.7 ± 4.3 years) with uncomplicated arterial hypertension. All patients were treated with combination of valsartan (80-320 mg; average dose 195 mg) and hydrochlorothiazide (12.5 mg). Ambulatory blood pressure monitoring, conventional and 2-dimensional speckle tracking echocardiography were performed before and 6 months after treatment. The concentrations of cardiotrophin-1 and soluble ST2 were determined by ELISA method. The data are presented as median and interquartile range.

Results. Treatment with valsartan/hydrochlorothiazide was effective and well tolerated. Target blood pressure level was achieved in 64 % of the patients. The LV global longitudinal strain (GLS) raised significantly after 6 months of treatment (Table). We found the reduction of mechanical dispersion - parameter, which indirectly reflects myocardial tissue homogenicity. The levels of circulating cardiotrophin-1 and soluble ST2 decreased by 37.93% and 19.74%, respectively (p &lt; 0.0001).

Conclusions. The 6-month therapy with valsartan/hydrochlorothiazide was associated with improvement of myocardial deformation parameters with concomitant reduction of soluble ST-2 and cardiotrophin-1 levels. These markers could be more sensitive than standard parameters for hypertensive patients" follow-up. However, this approach should be confirmed in future studies.

Parameter Baseline 6-month p Office SBP, mm Hg 148 (140; 157) 135 (124; 143) &lt;0.0001 Office DBP, mm Hg 89 (82; 96) 81 (74; 87) &lt;0.0001 LV GLS, % -19.6 (-18.1; -21.1) -20.4 (-18.9; -21.8) 0.01 Mechanical dispersion, ms 43 (37; 51) 41 (37; 48) 0.04 Cardiotrophin-1, pg/ml 12.2 (9.4; 16.81) 8.5 (6.26; 10.82) &lt;0.0001 Soluble ST2, ng/ml 25.3 (17.93; 29.72) 18.2 (13.93; 25.96) &lt;0.0001 Values are given as median and interquartile range

A set of serum markers detecting systemic inflammation in psoriatic skin, entheseal, and joint disease in the absence of C-reactive protein and its link to clinical disease manifestations

Background

C-reactive protein (CRP) is often normal in patients with psoriatic disease. Herein, we aimed to define markers of systemic inflammation in patients with monomorphic and polymorphic psoriatic skin, entheseal, and joint disease.

Methods

Three-step approach: (i) selection of serum markers elevated in psoriatic arthritis compared healthy controls from a panel of 10 different markers reflecting the pathophysiology of psoriatic disease; (ii) testing of these selected markers as well as C-reactive protein (CRP) in a larger cohort of 210 individuals- 105 healthy controls and 105 patients with psoriatic disease with either monomorphic skin (S), entheseal (E) or joint (A) involvement or polymorphic disease with various combinations of skin, entheseal and joint disease (SE, SA, EA, SEA); (iii) testing whether tumor necrosis factor (TNF) and interleukin (IL)-17 inhibitor therapy normalizes these markers.

Results

CRP was not elevated or was rarely elevated in the subgroups (S 0%, E 0%, A 20%, SE 7%, SA 33%, EA 27%, SEA 33%) despite active psoriatic disease. In sharp contrast, beta-defensin 2 and lipocalin-2 levels were elevated in the majority of patients with monomorphic skin (93% and 73%) and entheseal (both 53%), but not joint disease (27% and 20%). Conversely, elevations of calprotectin and IL-8 were found in the majority of patients with monomorphic joint disease (both 73%). IL-22 was elevated in all three monomorphic disease manifestations (S 60%, E 46%; A 60%). Furthermore, the vast majority of patients with polymorphic psoriatic disease (SE, SA, EA, SEA) showed widespread marker elevation. IL-17- and TNF inhibitor treatment significantly lowered all 5 markers of inflammation in PsA patients.

Conclusions

Systemic inflammation is detectable in the majority of patients with psoriatic disease, even if CRP is normal. The respective marker pattern depends on the manifestation of psoriatic disease with respect to skin, entheseal, and joint involvement.

1230 The atrial stiffness index in hypertensive women with indeterminate diastolic function

Background

Despite new 2016 ASE/EACVI guidelines on diastolic function (DF), there is still significant amount of patients with indeterminate results. The left atrial (LA) longitudinal strain could provide additional information in case of inconclusive results. Recenty, a new LA stiffness index was proposed as ratio between E/e" and LA global longitudinal strain (GLS). The purpose of this study was to test the diagnostic utility of LA stiffness index in hypertensive women with inderterminate DF.

Methods

The study enrolled 100 postmenopausal women (mean age 57 ± 4 years) with uncomplicated arterial hypertension, divided into 3 groups (normal DF, indeterminate DF, diastolic dysfunction). The DF was assessed with both 2009 and 2016 ASE/EACVI algorithms. LA longitudinal strain was measured as peak of deformation curves with R-wave variant of ECG triggering. The LA GLS was measured by averaging 12 segmental values. The atrial stiffness index was calculated as E/e" ratio to LA GLS.

Results

The prevalence of indeterminate DF was higher with assessment by 2016 algorithm (53 % vs 38 %). The E/e" ratio was significantly increased in patients with indeterminate DF compared to normal function (Table). LA GLS was decreased only in patients with inconclusive resuts by 2009 algorithm. LA stiffness index was increased gradually according to diastolic abnormalities severity. The significant difference between three groups was only found with categorization of patients by 2016 algorithm.

Conclusions

The novel LA stiffness index could be additional parameter of DF assessment in case of indeterminate results. However, it needs further validation in simultaneous echo-invasive studies.

LA mechanics in diastolic dysfucntion Parameter Normal diastolic function Indeterminate function Diastolic dysfunction p 2009 guidelines Prevalence, % 31 38 31 E/e" ratio 8,07 (7,36-9,6) 9,91 (8,44-11,6)* 11 (10,52-13)*^ p &lt; 0,0001 LA GLS, % 34,8 (30,2-39,9) 30,8 (26,5-34,9)* 28,9 (24,2-36)* p = 0,028 LA stiffness index 0,24 (0,18-0,31) 0,32 (0,27-0,39)* 0,37 (0,31-0,46)* p &lt; 0,0001 2016 guidelines Prevalence, % 40 53 7 E/e" ratio 8,8 (7,74-10,1) 10 (8,6-11,7)* 14 (12-14,9)*^ p &lt; 0,0001 LA GLS, % 34,2 (28,4-39,1) 30,8 (26,5-34,8) 29,6 (25,1-37,8) p = 0,18 LA stiffness index 0,27 (0,2-0,34) 0,33 (0,27-0,4)* 0,47 (0,38-0,59)*^ p = 0,001 The values are given as median and interquartile range. * - compared to normal function ^ - compared to indeterminate result

The Role of Dietary Fiber in Rheumatoid Arthritis Patients: A Feasibility Study

Short-chain fatty acids are microbial metabolites that have been shown to be key regulators of the gut-joint axis in animal models. In humans, microbial dysbiosis was observed in rheumatoid arthritis (RA) patients as well as in those at-risk to develop RA, and is thought to be an environmental trigger for the development of clinical disease. At the same time, diet has a proven impact on maintaining intestinal microbial homeostasis. Given this association, we performed a feasibility study in RA patients using high-fiber dietary supplementation with the objective to restore microbial homeostasis and promote the secretion of beneficial immunomodulatory microbial metabolites. RA patients (n = 36) under routine care received daily high-fiber bars or cereals for 28 days. Clinical assessments and laboratory analysis of immune parameters in blood and stool samples from RA patients were done before and after the high-fiber dietary supplementation. We observed an increase in circulating regulatory T cell numbers, favorable Th1/Th17 ratios, as well as decreased markers of bone erosion in RA patients after 28 days of dietary intervention. Furthermore, patient-related outcomes of RA improved. Based on these results, we conclude that controlled clinical studies of high-fiber dietary interventions could be a viable approach to supplement or complement current pharmacological treatment strategies.

P3837Both left atrial and left ventricular multilayer longitudinal strain are impaired in early stages of arterial hypertension in postmenopausal women

Background

Left ventricular (LV) hypertrophy and left atrial (LA) dilation are powerful prognostic predictors in arterial hypertension (AH). However, their use is limited in the early stages of hypertensive heart disease. LV and LA global longitudinal strain (GLS) are promising diagnostic markers for identification of early myocardial dysfunction. The purpose of the study was to evaluate the longitudinal deformation of left heart chambers in hypertensive postmenopausal women prior to LV hypertrophy and LA dilation development.

Methods

The study enrolled 100 postmenopausal hypertensive women (mean age 57.5±4.1 years), divided into 2 groups, and 26 healthy females (control group). The 1st group included 32 women with structurally normal hearts and the 2nd group consisted of 68 females with LV hypertrophy (LV mass index >95 g/m2) and LA dilation (LA volume index >34 ml/m2). LV multilayer GLS was calculated with 2D speckle tracking echocardiography. LA GLS was computed by averaging 12 segmental values with both P- and R- wave ECG-triggering. Strain was measured in contractile and reservoir phase, calculating GLS as sum of these values with P-wave variant, and as maximal peak of curves with R-wave method. The data are presented as median and interquartile range.

Results

The LV GLS was significantly lower in hypertensive women with structurally normal hearts in all myocardial layers compared to healthy females (table). The LA longitudinal strain was reduced due to the deterioration of reservoir phase. The reduction of LA GLS in hypertensive women with structurally normal hearts was detected using R-wave triggering method only (opposite to P-wave method).

Left heart chambers longitudinal strain Parameter Control group 1st group 2nd group p LV GLS endo, % −23.75 (−20.3; −25.15) −21.25 (−19.6; −22.35)* −21.2 (−20.14; −22.9)* 0.047 LV GLS mid, % −21.4 (−18.5; −22.6) −19.1 (−17.8; −20.45)* −19.1 (−17.95; −20.15)* 0.03 LV GLS epi, % −18.7 (−16.75; −20.2) −16.95 (−15.95; −18.5)* −17.1 (−15.96; −18.05)* 0.03 P-wave triggering   LA LS in contractile phase, % −15.75 (−13.41; −16.37) −15.38 (−13.69; −17.77) −14.99 (−12.97; −16.89) 0.47   LA LS in reservoir phase, % 17.19 (15.4; 20.2) 13.19 (8.8; 18.03)* 13.54 (10.45; 16.19)* 0.0004   LA GLS, % 31.01 (25.11; 35.59) 28.37 (24.29; 32.5) 26.73 (23.21; 30.54)* 0.02 R-wave triggering   LA GLS, % 38.3 (34.54; 43.43) 33.63 (30.11; 36.28)* 30.77 (26.23; 36.11)* 0.0002 *p<0.05 compared to control group.

Conclusions

LV multilayer and LA GLS are reduced prior to LV hypertrophy and LA dilation development in hypertensive postmenopausal women and may be considered as early signs of myocardial dysfunction.

Certolizumab pegol in the treatment of Takayasu arteritis

Objectives

Certolizumab pegol (CZP) is a PEGylated antigen-binding fragment-fragment of a humanized mAb neutralizing TNF. It lacks Fc-fragment and has a very low potential to cross the placenta. We aimed to report the efficacy and safety of CZP in a case series of patients with refractory Takayasu arteritis (TA).

Methods

Ten females of reproductive age (18-35 years) with TA were treated with CZP (at a dose of 400 mg at weeks 0, 2 and 4 and at 200 mg every 2 weeks thereafter) for a median of 10 months (range 3-28). Prior to CZP administration all patients received glucocorticoids and ± MTX, CYC, AZA, HCQ, LEF or MMF. Six patients were previously treated with other biological anti-cytokine drugs. The National Institutes of Health criteria and the Indian Takayasu Clinical Activity Score 2010 were used to define disease activity.

Results

All patients rapidly responded to treatment with CZP and were able to taper prednisone and MTX doses. Treatment with CZP resulted in a significant decrease in median serum CRP levels and normalization of Indian Takayasu Clinical Activity Score 2010 score in 9 of 10 patients. Remission of systemic vasculitis was achieved in all patients. Seven patients maintained remission for at least 4 months, while one patient developed relapse after 2 years of CZP treatment. Side effects included mild infections (n = 5).

Conclusion

Our case series suggests that CZP may be an effective and steroid-sparing treatment option in patients with active TA even if they did not previously respond to other TNF inhibitors or tocilizumab.

[A comparative characteristic of antigenic properties of recombinant and native hbs-antigens with G145R mutation and evaluation of their immunogenicity]

BACKGROUND

One of the important reasons for spreading of hepatitis B virus (HBV) under conditions of vaccinepressure is emergence of escape mutations. Prevalent G145R mutation in S-gene leads to the most expressed changes of serological properties of HBV. Consequently, HBsAg is modifed so thoroughly that it cannot be recognized by the majority of anti-HBs. Mutant G145R also differs from a wild type HBsAg by its immunogenic properties. At present, the relevance of enhancement of hepatitis B vaccine in view of mutant virus variants has been recognized.

OBJECTIVES

a comparative study of antigenic and immunogenic properties of native and recombinant G145R mutants and an estimation of possibility for developing antigenic component of hepatitis B vaccine with G145R mutation in HBsAg.

METHODS

antigenic properties of recombinant HBsAg with G145R mutation were compared with each other and with native mutants by serological fngerprinting method. Then, BALB/c mice and sheep were immunized with selected recombinant antigen under different protocols. Titers of antibodies specifc to wild type or mutant G145R type of HBsAg in sera of immunized animals were measured.

RESULTS

it was found that not all the recombinant HBsAg variants with G145R substitution have the same antigenic properties as native HBsAg with similar mutation. Recombinant HBsAg selected according to the principle of antigenic similarity possesses immunogenicity in mice and sheep causing the production of antibodies reacting with native wild and mutant type HBsAg. It was shown that mutant antigen is less immunogenic, requires larger doses and more time for the development of immune response; however, it is capable of causing an antibody level comparable with wild type antigen.

CONCLUSIONS

preliminary selection of recombinant HBsAg containing G145R mutation with antigenic and immunogenic properties similar to the native analogue creates the basis for development of a specifc component of hepatitis B vaccine with escape mutation G145R in HBsAg.

MORPHOLOGICAL ANALYSIS OF HEPATITIS B VIRUS WITH ESCAPE MUTATIONS IN S-gene G145R AND S143L

BACKGROUND

In terms of serological properties and immunization, the wild type of HBsAg HBV and its G145R mutant behave as different antigens. This testifies to serious structural changes, which presumably could have a significant impact on the morphogenesis of virions and subviral particles. Nevertheless, morphological and ultrastructural investigations of HBV with G145R mutation have not been carried yet.

OBJECTIVES

Research of structural and morphological organization of HBV in the presence of the G145R escape mutation.

METHODS

Studies of sera, purified viruses and recombinant HBsAg were carried out by transmission electron microscopy by the method of negative staining and indirect reaction of immunelabeling using monoclonal antibodies of different specificity. Specimens of wild type HBV and HBV with S143L mutation obtained in an identical manner were used as the control.

RESULTS

The presence of typical virus particles of HBV was shown in the specimens of wild strain and HBV with S143L mutation. Specimens of HBV with G145R mutation were characterized by expressed morphological heterogeneity. In the initial serum and in the specimen of purified virus containing G145R mutant, large oval particles 60-70 nm and up to 200 nm in size, respectively, were found. The presence of antigen structures of HBV in all heterogeneous forms was confirmed. It was shown that forming of subviral particles in the process of expression of the recombinant HBsAg with G145R mutation depends on conditions of expression and purification of the protein. They can vary from well-formed circular and oval particles to practically unstructured fine-grained masses.

CONCLUSION

Direct data on the impact of G145R escape-mutation in S-gene, in contrast to S143L mutation, on the morphogenesis of virions and subviral particles of HBV were obtained.

[The detection of immunoglobulins G to agents of TORCH-infections using technique of multiplex immunoassay on the basis of FOSFANtm technology.]

The immune chip is developed for detecting immunoglobulins G to agents of four infections of TORCH-complex (toxoplasmosis, German measles, cytomegalovirus and herpes viral infections) on the basis of FOSFANtm technology. The sensitivity and specificity of simultaneous detection of IgG on immune chip were comparable with indices of commercial immunoenzyme test-systems, including under analysis of standard panels of serums. This permits considering derived results as a basis for development of commercial multiplex test intended for highly productive screening of TORCH-infections in clinical laboratory.

[THE SELECTION OF ANTIGENS FOR DETECTING OF IMMUNOGLOBULIN G TO CYTOMEGALOVIRUS ON THE BASIS OF FOSFAN TECHNOLOGY]

The results of selection of composition of antigens to cytomegalovirus in the structure of multiplex test on the basis of FOSFAN™ technique are presented. In the process of detection of immunoglobulin G (IgG) to this virus the best indicators of sensitivity were registered with mosaic antigen containing immunodominant sequences of proteins pp150, gB, pp28 and pp52; reliably lower indicators of sensitivity was registered with phosphoprotein pp150; the lowest indicators of sensitivity were registered with proteins gB and pp65. The specificity made up from 93.5% to 96.8% independently of type of antigen. The mosaic antigen ensured the best ratio between sensitivity and specificity of immunoassay and is considered as the main component of immunochip for detecting IgG to cytomegalovirus.

[Predictors of cardiac arrhythmias in patients with arterial hypertension during exercise stress testing]

Arterial hypertension is an important risk factor for atrial and ventricular arrhythmias. 203 male patients were examined in order to identify predictors of cardiac arrhythmias in patients with arterial hypertension during exercise stress testing. All participants were studied by 24-hour ambulatory blood pressure monitoring, transthoracic echocardiography, an ultrasound scan of the carotid arteries and treadmill test. 47,3% of patients presented cardiac arrhythmias during exercise stress testing. The left ventricular mass, diastolic function and carotid intima-media thickness were found to be independent predictors of exercise-induced arrhythmias. The use of the exercise stress testing may be reasonable for additional risk stratification in hypertensive patients.

[Molecular diagnosis and frequencies of primary hypolactasia in populations of RUSSIA and neighboring countries]

The digestion of the milk sugar (lactose) is observed every normal child but not in every adult. The decreased lactase synthesis in some adults results in problems with digestion of the whole milk (primary hypolactasy). An association of lactase activity in adults with carrying of the allele T within the polymorphism C/T-13910 located upstream of the lactase gene and 100% association of hypolactasy with the genotype C/C has recently been shown for a Finnish sample. In the present work we determined the LCT* C/T_13910 genotypes and allele frequencies in populations from Russia. The genotype C/C frequencies varied from 36.6% for Russians to 88.2% for Chukchi and were close to the published medical and epidemiological data on hypolactasy frequencies in respective populations. Genotyping was performed by three different methods to identify the optimal one. Our results have shown that the studied locus is the key determinant for the primary hypolactasy development in various human populations. Consequently, the DNA diagnostics of the C/C genotype carrying is a promising predictive test to detect the primary hypolactasy long before its clinical development. Practical application of this type of diagnostics would be a step towards the individual-oriented medicine.

[Analysis of the DRD4 gene polymorphism in populations of Russia and neighboring countries]

Allele and genotype frequencies of the VNTR polymorphism in the third exon of human DRD4 gene were determined in 544 individuals living in Russia (Russians, Bashkirs, Tatars, and Mordovians) and in the neighboring countries (Kazakhs and Ukrainians). The data obtained were compared with the allele frequency distribution patterns reported for the populations of Eurasia. Similarly to other Eurasian populations, in our population samples R4 allele was prevalent (64 to 87%). The frequency of this allele in the populations of Western Europe constitute 61 to 71%, while in the populations of Asia it varies from 74 to 96%. In this respect, the populations studied occupied the intermediate position. In the samples examined the R7 allele frequency decreased from 7% in Ukrainians to 1% in Bashkirs, while in Kazakhs and Mordovians the allele was absent. This finding was consistent with the R7 allele distribution pattern in the populations of Eurasia, characterized by higher frequency in the West and lower frequency or absence of the allele in the East. In the group of 22 Eurasian populations, the R7 allele frequency negatively correlated with the frequency of the R4 allele (r = -0.86 at P < 0.001). Unlike the R4 and R7 alleles, the frequency of which changed in the eastward direction, the R2 allele frequency distribution displayed slightly expressed latitudinal increase southwards. The DRD4 genotype distribution deviated from the equilibrium in most of the samples examined. In some samples, statistically significant increase of the R2/R2 homozygotes frequency was demonstrated. One of the possible explanations of this phenomenon is assortative mating with respect to phenotypic (behavioral) allele manifestation. The data obtained can serve as the basis for the investigation of the possible role of the DRD4 alleles as the risk factors for the development of alcoholism and other types of addictions.

[Designing and clinical testing of immune-enzyme and immunofluorescence test systems for serodiagnosis of ixodes borreliosis]

The methods of immune enzyme assay (MIEA) and of lanthanide immunofluorescence analysis (LIFA) were used to work out the test systems for the detection (in blood serum of patients) of specific IgM IgG antibodies to the B. burgdorferi spirochete--a causative agent of ixodic borrelioses. The test system was clinically tested versus the indirect immunofluorescence reaction (IIFR) and commercial immune enzyme test system (CIET). The results of antibodies' detection were shown to correlate with the analysis data for the same sera in IIFR and to be in line with a real presence or absence of the disease. Test systems based on LIFA were proven to be most sensitive and specific.

[Study of the effect of antiviral drugs on the reproduction of the respiratory syncytial virus by enzyme immunoassay]

A test system based on EIA was developed for evaluating the efficiency of drugs active towards the respiratory syncytial virus (RSV) in cell culture. Virasole and its structural analog ribamedii active towards RSV infection and arbidol whose activity in RSV infection is unknown were tested. Like virasole and ribamedil, arbidol inhibited the expression of RSV antigens, the inhibitory effect increasing with the drug concentration and decreased with increase of the multiplicity of virus infection. MIC50 for arbidol, virasole, and ribamedil were 10, 5, and 6 micrograms/ml, respectively. These data prompt clinical trials of arbidol in RSV infection.

[The role of hepatocytes, Kupffer, and endothelial cells of the liver in blood lipoprotein metabolism]

The rates of blood lipoprotein adsorption by hepatocytes and nonparenchymal cells (NPC) of rat liver have been quantitatively characterized. It was found that the lipoprotein-adsorbing capacity of NPC is higher than that of hepatocytes: 5.6 times for very low density lipoproteins (VLDL), 4.3 times for low density lipoproteins (LDL) and 14.4 times for high density lipoproteins. Stimulation of the mononuclear phagocyte system by a lipopolysaccharide from Serratia marcescens resulted in a significant reduction of blood serum levels of HDL3, LDL and glucocorticoids. Under these conditions the binding of [125I]HDL to hepatocytes increased, while that to Kupffer's cells decreased considerably. In response to stimulation of liver resident macrophages (Kupffer's cells) the rate of protein biosynthesis in hepatocytes increased together with an increase in the rate of [14C]leucine incorporation into the protein component of the blood serum lipoproteins. Enhanced gene expression in the hepatocytes seems to be associated with the cooperative action of HDL and glucocorticoids. Adsorption of lipoproteins by activated Kupffer's cells is due to the receptor-mediated endocytosis, resulting in a decrease of the binding capacity of these cells for HDL and LDL.

Detection of tick-borne encephalitis virus in ixodid ticks collected in natural foci by time-resolved fluoroimmunoassay

Time-resolved fluoroimmunoassay (TR-FIA) was used for the first time for evaluation of infestation of ixodid ticks with tick-borne encephalitis virus. Comparison of TR-FIA results with those obtained in enzyme immunoassay and by virus isolation confirmed the high efficacy of the method in question. Positive results of TR-FIA coincided with the data of virus isolation in 83.6% cases, the level of false-negative results did not exceed 1.2%, the overall time consumption amounted to about 1.2 hr.

[The use of lanthanide immunofluorescence analysis for demonstrating the antigen of viral hepatitis A]

The study dealt with the development of an express method for detection of hepatitis A virus (HAV) antigen employing lantanides, especially europium. The new time-resolved fluoroimmunoassay (TRFIA), alongside with a significant shortening of the time for reaction, was also 8 times as sensitive as the analogous enzyme immunoassay. The TRFIA may be used effectively both for control of the antigen amplification in HAV-infected cell culture and for early diagnosis of acute forms of viral hepatitis A.

[The demonstration of the Venezuelan equine encephalomyelitis virus by the method of indirect lanthanide immunofluorescent analysis]

A test system of indirect time-resolved fluoroimmunoassay (TR-FIA) was developed and tested on an alpha-virus, Venezuelan equine encephalomyelitis virus. The indirect TR-FIA test system was shown to be highly effective in the detection of antigens of this virus. Not differing in specificity from the direct TR-FIA, the newly developed test system was 4 times as sensitive.

[A comparison of the results of analyzing the clinical data from gynecological, ophthalmological and dental patients using a set of rapid methods for the diagnosis of herpesvirus infection]

Analysis of biological specimens from gynecological, ophthalmological, and stomatological patients was carried out using current express methods for diagnosis of herpes virus infection developed by the authors: enzyme immunoassay (EIA), time-resolved fluoroimmunoassay (tr-FIA), molecular hybridization and conventional immunofluorescence technique. Monoclonal antibodies (MCA) generated by us with epitope specificity for gpD HSV-2 were used in EIA and tr-FIA. F(ab')2-fragments of MCA used as sorbents and for preparation of conjugates were found to be by 250% more sensitive than intact IgG used for similar purposes. The employment of EIA based on MCA F(ab')2-fragments contributed to detection of 0.2-0.6 ng of virus-specific protein in a specimen. Comparison of the results of analysis of clinical specimens of broad spectrum (mucous secreta from the cervical canal of the uterus and posterior vault of the vagina, saliva, lacrimal fluid) by the above express methods for diagnosis of herpes virus infection revealed a high percentage of positive findings, none of the methods providing 100% diagnosis. The use of a set of methods makes the resultant information more objective. Therefore, in future the data obtained by a number of current express methods for herpes diagnosis should be compared.

[The differentiation of viruses in the Venezuelan equine encephalomyelitis complex by using monoclonal antibodies and lanthanide immunofluorescence analysis]

Potentialities of differentiation between Venezuelan equine encephalomyelitis (VEE) complex viruses by time-resolved fluoroimmunoassay and enzyme immunoassay were studied. For this, 4 test systems were used based on different combinations of native and labeled polyclonal antibodies to VEE virus, strain Trinidad, and monoclonal (MCA) antibody MAK 14-7 to protein EL of this virus. The maximal sensitivity and specificity was achieved in the test system formed from native MCA MAK 14-7 for sensitization of the solid phase and labeled polyclonal immunoglobulins for demonstration of the test results. This combination of antibodies allowed to differentiate the epidemic variant of VEF/Trinidad (IA) from epizootic variants of Mucambo (III), Pixuna (IV) and attenuated strain No. 230.

[The design and trial of conjugates for performing lanthanide immunofluorescence analysis]

The possibility of using a number of complexons for labeling of antibodies to Venezuelan equine encephalomyelitis virus and to adenovirus with europium ions was studied. The resultant conjugates, irrespective of the type of complexon, were shown to retain their immunochemical activity and could be used for lanthanide immunofluorescence analysis of virus-specific antigens.

[Effect of resident macrophages on protein biosynthesis in the liver under conditions of reparative regeneration after partial hepatectomy]

In reparative regeneration of the liver after partial hepatectomy stimulation of the resident macrophages by lipopolysaccharides increases sharply the rate of 14C-leucine inclusion into total protein and into the soluble protein of the tissue supernatant. It is shown that synthesis not only of proteins necessary for restoration of the structural intactness of the liver increases but also of some blood serum proteins: total protein, protein of very low-density and low-density lipoproteins (VLDL and LDL) and of high-density lipoproteins (NDL2). The specific radioactivity of HDL3 protein reduces under such conditions. Increased protein biosynthesis in the liver under the effect of lipopolysaccharides precedes and contributes to intensification of the proliferative activity of the tissue of the damaged liver.

[Stat-diagnosis of influenza using lanthanide immunofluorescence analysis]

A test system for influenza diagnosis has been developed on the basis of monoclonal antibodies to influenza A and B virus proteins using the principles of lanthanide immunofluorescence analysis. The diagnostic test system was shown to be highly specific in detecting influenza A and B virions in model systems. For the one-step variant of a double sandwich used in the study, the total time of diagnostic experiment using clinical materials was shown to be reduced to 15-20 min.

Antigenic reactivity of matrix protein and nucleoprotein of influenza virus as detected by EIA after dissociation with different detergents

Solid phase enzyme-immunoassay (EIA) was employed to assess the antigenic reactivity of matrix protein (M) and nucleoprotein (NP) of influenza A virus adsorbed to polystyrene in the presence of different detergents such as beta-octaglucoside (OG), Triton X-100, Tween-20, sodium dodecylsulphate (SDS), sodium deoxycholate (Doch-Na), Nonidet P-40 (NP-40), and sarcosyl at concentrations ranging from 0 to 2%. The antigenic reactivity of NP was the highest in the absence of detergents. For M protein, Doch-Na, SDS, NP-40 and sarcosyl of 0.05-0.1% enhanced the chromatophoric response in EIA 1.5-2 times. In contrast, the antigenic reactivity of M protein remained unchanged after OG or Triton X-100 treatments, and it decreased in the presence of Tween-20.

[Isolation and characteristics of monoclonal antibodies to influenza virus types A and B]

Monoclonal antibodies (MCA) to influenza type A (10F) and B (5H and 6H) viruses have been prepared. By immunoblotting method, MCA 10F were found to be specific for NP-protein of influenza A virus, and MCA 5H and 6H to be specific for hemagglutinin of influenza B virus. It was established that the 10F clone interacted with all the investigated influenza A virus strains with different antigenic formulae (H1N1, H2N2, H3N2) and could be used for typing of this virus type. Clones 5H and 6H react specifically with hemagglutinins of influenza B viruses isolated in 1940, 1979, and 1983 which makes them useful for diagnosis of influenza B.

The influence of the isolation technique of influenza virus nucleoprotein on its antigenic properties

ELISA has been used to study the antigenic properties 1. of influenza virus nucleoprotein (NP-1) isolated from virions with the help of preparative polyacrylamide gel electrophoresis (PAGE); 2. of virion ribonucleoprotein (NP-2), and 3. of NP structures prepared by dissociation of ribonucleoprotein into RNA and protein in sucrose gradient containing NaCl (NP-3). The investigation of immunologic cross-reactivity has shown complete identity of NP-2 and NP-3 and their striking difference from NP-1. In contrast to NP-2, NP-3 was not contaminated by other virus antigens, it was a good immunogen and could be used for preparation of monospecific antisera of high titre. NP-1 did not induce a high antibody response,however, like NP-2 and NP-3, it retained its capacity to react with antisera to native virus. Owing to its simple production and high yield, this protein can be used in serodiagnosis for testing the antibody level against NP-protein in convalescent sera.

[Reversible dissociation of influenza virus ribonucleoprotein]

Dissociation of influenza virus RNP under the effect of salt was studied. Separation of RNA and protein components of influenza virus RNP was shown to occur in a linear 15-30% sucrose concentration gradient containing 1.1 M NaCl. Upon RNP dissociation, protein-protein interactions between individual molecules of the structural protein were retained. The sedimentation coefficient of the protein component was 52S. The possibility of reassociation of the RNA-protein complex was studied. More complete reassociation was observed to occur in the presence of 0.1 M NaCl. The resulting RNA-protein complex morphologically is similar to the native RNP of influenza virus.

[Proteolytic cleavage of influenza virus matrix protein and nucleoprotein in an in vitro system]

Proteolytic modification of NP-protein which is a part of influenza virus ribonucleoprotein (RNP) was studied in vitro. NP-protein of influenza virus (mol. weight 56 000) was shown upon RNP treatment with bromeline to undergo proteolytic cleavage revealing 2 more polypeptides with molecular weights of 53 000 and 45 000 daltons. The same classes of NP-proteins were present in RNPs recovered from subviral units obtained by virus treatment with bromeline at buffer pH below 7. Electrophoresis in 12% polyacrylamide gel under reducing conditions of subvirus units obtained by treatment of virions with bromeline at the buffer pH below 7 also demonstrated proteolytic cleavage of M-protein present in them into fragments with molecular weights of 8 500-12 000 daltons. Similar results were obtained upon direct treatment with bromeline of M-protein isolated from virions.

[Preservation of the enzyme activity of horseradish peroxidase administered into the gastrointestinal tract of adult dogs and rats]

Enzymatic activity of horse radish peroxidase administered to the gastrointestinal tract of adult dogs and rats was assessed. It was discovered that in adult dogs, 30% of the protein reached the distal parts of the small intestine in a non-splitted form. As early as two hours after administering horse radish peroxidase over 15% of active enzyme was detectable in the gastrointestinal tract of adult rats. 0.5% of non-splitted enzyme was found in the rat large intestine.

[Vesicular peroxidase transport by the epithelial cells of the small intestine in the adult rat]

Electron cytochemistry has shown that after administering horse radish peroxidase to the gastrointestinal tract of adult rats it penetrates the epithelial barrier of the small intestine and is transported functionally intact into the circulation. Peroxidase was largely absorbed on the apex of the villi, entered the enterocytes by pinocytosis and was transported via the cytoplasm within the pinocytotic vesicles. Peroxidase was not detected in cytosole or endoplasmic reticulum of the enterocytes. It is assumed that the disclosed functional heterogeneity of absorption depends on adsorption selectivity of the microvilli of the enterocyte apical membrane. It is concluded that the pinocytotic mechanism also functions in adult mammals, by which foreign protein is transported to the circulation, causing allergic reactions.

[Circular dichroism spectra study on the ribonucleoprotein structure of influenza virus]

The CD spectra of Influenza virus RNA and RNP were examined in the ultraviolet region (220--320 nm) at different temperatures, NaCl and urea concentrations. The magnitude of the positive band for RNP decreases gradually upon increasing the temperature, indicating that rather weak interaction between RNA and protein occurs. However the temperature drastically affects the intensity of the negative band about 222 nm. In the temperature range where the protein melts the positive band at longer wavelengths shows a temperature dependence that is similar for RNP and free RNA. Addition of NaCl results in an increase in intensity and blue shift of the positive CD band of RNP. In the presence of 1 M NaCl the CD spectrum of RNP is very close to that of protein-free RNA. Urea concentrations up to 10 M has little effect on the CD spectrum of RNP. These results suggest that only ionic but not hydrophobic and hydrogen bondings are involved in the RNA-protein interaction in Influenza virus RNP.