Screening for rheumatoid arthritis-associated interstitial lung disease-a Delphi-based consensus statement

OBJECTIVE

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is a major driver of premature mortality in patients with rheumatoid arthritis (RA). Detection of RA-ILD is crucial but requires awareness among the treating physicians. To date, however, there is no international recommendation concerning screening for ILD in RA patients.

METHODS

After a systematic literature review, the modified Delphi technique in combination with the nominal group technique was used to provide a Delphi consensus statement elaborated by an expert panel of pneumonologists, rheumatologists, and a radiologist. Based on the available evidence, several clusters of questions were defined and discussed until consent was reached.

RESULTS

A screening algorithm for ILD in patients with RA based on clinical signs, respiratory symptoms, and risk factors has been developed. Further, the recommendations address diagnostic tools for RA-ILD and the follow-up of RA patients qualifying for ILD screening.

Associations between nailfold capillary aberrations and autoantibodies in children and adults with Raynaud's phenomenon

OBJECTIVE

To characterise associations between individual nailfold capillary aberrations with autoantibodies in a cross-sectional study on children and adults with Raynaud's phenomenon (RP).

METHODS

Consecutive children and adults with RP and without previously known connective tissue disease (CTD) systemically underwent nailfold capillaroscopy and laboratory tests for the presence of antinuclear antibodies (ANA). The prevalence of individual nailfold capillary aberrations and ANA was assessed, and the associations between individual nailfold capillary aberrations and ANA were analysed separately in children and adolescents.

RESULTS

In total, 113 children (median age 15 years) and 2858 adults (median age 48 years) with RP and without previously known CTD were assessed. At least one nailfold capillary aberration was detected in 72 (64%) of included children and in 2154 (75%) of included adults with RP (children vs adults p<0.05). An ANA titre ≥1:80, ≥1:160 or≥1:320 was observed in 29%, 21% or 16% of included children, and in 37%, 27% or 24% of screened adults, respectively. While the occurrence of individual nailfold capillary aberrations was related to the presence of an ANA titre of ≥1:80 in adults (reduced capillary density, avascular fields, haemorrhages, oedema, ramifications, dilations and giant capillaries: each p<0.001), no comparable association between nailfold capillary aberrations and ANA was observed in children with RP without previously known CTD.

CONCLUSION

In contrast to adults, the association between nailfold capillary aberrations and ANA might be less pronounced in children. Further studies are warranted to validate these observations in children with RP.

POS0446 Arp2/3 AS A Lasp1 INTERACTION PARTNER REGULATES CELL-TO-CELL CONTACT FORMATION OF FIBROBLAST-LIKE SYNOVIOCYTES IN RA

Background

In rheumatoid arthritis (RA), fibroblast-like synoviocytes (FLS) undergo a stable transformation resulting in an aggressive phenotype mediating cartilage damage by increased levels of adhesion molecules. In this context, Lasp1 and the Arp2/3 complex are of interest because they modulate actin organization and focal adhesion turnover.

Objectives

In this study, the effects of Arp2/3 on cadherin-11 mediated cell-to-cell contact formation have been investigated using the arthritic hTNFtg mouse model.

Methods

Expression levels of Lasp1 and Arp2/3 protein complex were investigated in synovial tissue of wild type (wt) and hTNFtg hind paws by immunohistochemistry. Primary FLS were analysed, respectively and co-immunoprecipitation experiments were performed. In addition, lasp1-/- mice were interbred with hTNFtg animals and offspring were evaluated for disease progression and joint destruction. To further study the role of Arp2/3 in the function of the cadherin-11 adhesion complex, the effects of an Arp2/3 inhibitor (CK666) on cell-to-cell contact formation in FLS derived from hTNFtg and lasp1-/-hTNFtg mice were investigated by stainings. To assess signaling pathway activation, cells were stimulated with the growth factor PDGF.

Results

Upregulated Lasp1 levels were found in synovial tissue and FLS of hTNFtg compared to wt mice. Assays showed that Arp2/3 is part of the adherens junction (AJ) machinery in FLS although Arp2/3 expression levels were not changed between the genotypes. In vivo evaluation of lasp1-/-hTNFtg mice revealed a milder arthritis score, less cartilage degradation and reduced FLS attachment to articular cartilage compared to hTNFtg mice. In vitro, the loss of Lasp1 led to clear alterations in AJ arrangement indicated by altered β-catenin pattern. As expected, β-catenin expression was mainly located at adhesion sites between adjacent cells. In hTNFtg FLS, these structures were characterized by a zipper-like pattern. In contrast, these structures were disrupted in lasp1-/-hTNFtg FLS. Interestingly, CK666 induced zipper-like structures in hTNFtg FLS comparable to the pattern found in lasp1-/-hTNFtg cells. Furthermore, lasp1-/-hTNFtg FLS showed decreased Src phosphorylation following PDGF stimulation in comparison to hTNFtg FLS.

Conclusion

Lasp1 represents an interesting target involved in RA-caused joint destruction, because its loss results in significantly reduced cartilage destruction and altered FLS contacts mediated by Arp2/3.

Disclosure of Interests

None declared.

AB0718 Immune-apheresis in patients with inflammatory myopathies, a case series

Background

Idiopathic inflammatory myopathies (IIM) comprise a heterogenous group of autoimmune diseases characterised by inflammation of muscle and affection of other organs, such as lung or skin. Some cases of IIM non-responsive to conventional treatment with glucocorticoids and DMARDs require treatment escalation. There are only limited data on efficacy and safety of immune-apheresis (IA) in IIM patients.

Objectives

This retrospective cohort study aims to determine whether IA is effective in treating therapy-refractory IIM.

Methods

Patients with active IIM undergoing IA (either plasma-exchange or immunoadsorption) at the Medical University Vienna were included in this explorative study. Patient characteristics and clinical data including serum levels of creatine kinase and concomitant medication were extracted from electronic medical records. As a primary endpoint, efficacy of IA was evaluated four weeks after initiation of IA, calculating absolute and relative change of CK-values as well as changes in steroid dose. Secondary endpoints included absolute and relative changes of CK-values at week 8 and week 12.

Results

From 2000 to 2021 25 IIM patients treated with IA were identified, 24 could be used for further analyses. Patient characteristics at start of IA are displayed in Table 1. Subtypes of IIM included dermatomyositis (DM 54.2%), polymyositis (PM 8.3%), Overlap-Myositis (20.8%), mmune-mediated-necrotising-myositis (IMNM 8.3 %), and antisynthetase syndrome (ASS 8.3 %). The majority of patients received concomitant steroid therapy (87.5 %) and DMARD therapy (62.5 %).

Table 1.

Cohort descriptives:

Population, n (n= female%)24 (n=19;79.2 %)Age at Baseline (years; mean [SD];)42.5 [11.5]Subtyp Myositis (%,n)-Dermatomyositis54.2 % (13)-Polymyositis8.3 % (2)-Overlap-Myositis20.8 % (5)-Immune mediated necrotising myositis8.3 % (2)-Anti-Synthetase-Syndrom8.3 % (2)Immune Apharesis within 4 weeks (number of cycles)mean: 9.54,median: 9.5,[IQR: 8; 11.5]Previous DMARDs (%,n)-Any DMARDs-Mean number of previous DMARDs amongst all 24 patients62.5% (15)-Azathioprin33.3% (8)-Methotrexat45.8% (11)-Rituximab16.7% (4)-Mycophenolat mofetil16.7% (4)-Cyclophosphamid8.3% (2)-Ciclosporin8.3% (2)-(Hydroxy)-Chloroquin20.8% (5)-Etanercept4.2% (1)-Infliximab4.2% (1)Concomitant DMARDs (%,n)-Any DMARDs62.5% (15)-Azathioprin20.8% (5)-Methotrexat20.8% (5)-Rituximab4.2% (1)-Cyclophosphamid4.2% (1)-Ciclosporin4.2% (1)-(Hydroxy)-Chloroquin8.3% (2)Concomitant Steroids % (n)87.5% (21)-Dose prednisone at Baseline (mg/day; median [IQR])25 [12.5; 50] (21)-Dose prednisone at week 4 (mg/day; median [IQR]12.5 [0; 37.5] (22)CK-level at baseline (U/ml; median [IQR])970.5 [157.5; 3795.5]Change in CK-values from baselineAbsolute changeRelative change-to week 4 (n=24)median [IQR] U/ml% [IQR]-to week 8 (n=16)304.5 [28.8;2051]49.1 [22.4; 79.3] %-to week 12 (n=15)648.5 [25.8; 3939.3]70.0 [13.6; 87.7] %559 [-7; 3988]63.8 [-5.8; 98.1] %

Until week 4 significant decrease in CK-values was observed in 21/24 patients (p<0.01; Figure 1), from median 970.5 [157.5; 3795.5] to 347[63; 1010] U/ml. Median [IQR] dose reduction of steroids was 12.5 [0; 12.5] mg/day absolute and 25% [0%, 100%] relative. No differences were observed within patients of different myositis subtypes. One patient died after 4 weeks, in 15 patients IA was maintained until week 12. Significant reduction in CK-values was observed from baseline to week 8 and 12 respectively (141 [78; 460], 111 [57;338]. Median and relative changes from baseline until week 12 are displayed in Table 1.

Figure 1.

Individual response in CK-levels from baseline to week 12

Conclusion

Immune-apheresis seems an effective therapeutic option in refractory IIM, leading to decrease of CK-values and steroid dose.

References

[1]Lundberg IE. Expert Perspective: Management of Refractory Inflammatory Myopathy. Arthritis Rheumatol. 2021 Aug;73(8):1394-1407.

Disclosure of Interests

None declared

OP0079 SYNOVIAL FIBROBLASTS – T CELL INTERACTIONS ARE MAJOR DRIVERS OF INFLAMMATION: A CLOSER LOOK INTO THE JOINT

Background

Rheumatoid Arthritis (RA) is a chronic inflammatory disease, which is characterized by synovial inflammation resulting in bone and cartilage destruction. Crosstalk between activated fibroblast-like synoviocytes (FLS) and immune cells, such as CD4+ T cells, within the synovium might amplify synovial inflammation and joint destruction.

Objectives

To define the interaction profile of activated FLS and CD4+ T cells within an inflammatory setting and to elucidate its consequence on synovial inflammation.

Methods

To screen for factors that activate FLS in RA, isolated FLS were treated with different inflammatory cytokines and transcriptomic changes were measured with RNA-seq. Fluorescence activated cell sorting (FACS) purified naïve CD4+ T-cells from the same patients were co-cultured with the cytokine pre-treated FLS. Automated fluorescence microscopy and downstream bioinformatic image analysis allowed visualization and quantification of cell-cell interactions. After co-culture T-cells were isolated and T-cell activation, proliferation and differentiation was determined by flow cytometry.

Results

To model the in vivo situation, FLS were pre-stimulated with different pro- and anti-inflammatory cytokines. RNA-seq revealed cytokine specific activation patterns of FLS. Correspondingly, we observed distinct CD4+ T cells – FLS interaction profiles depending on the cytokine used for FLS activation. In line with distinct interaction profiles, specific patterns in CD4+ T cells activation, proliferation and differentiation of naïve T cells into CD62Lhigh CD45ROhigh memory T cells could be detected. Signatures of cytokine-stimulated FLS could be identified in transcriptomic data from synovial tissue samples.

Conclusion

Within this study, we describe how cytokine induced CD4+ T cells – FLS interactions impact on T-cell proliferation, activation and differentiation.

References

[1]Zhang F, Wei K, Slowikowski K, Fonseka CY, Rao DA, Kelly S, et al. Defining inflammatory cell states in rheumatoid arthritis joint synovial tissues by integrating single-cell transcriptomics and mass cytometry. Nat Immunol. 2019.

[2]Smolen JS, Aletaha D, Barton A, Burmester GR, Emery P, Firestein GS, et al. Rheumatoid arthritis. Nat Rev Dis Primers. 2018;4:18001.

[3]Smolen JS, Aletaha D, McInnes IB. Rheumatoid arthritis. The Lancet. 2016;388(10055):2023-38.

[4]Bartok B, Firestein GS. Fibroblast-like synoviocytes: key effector cells in rheumatoid arthritis. Immunol Rev. 2010;233(1):233-55.

[5]Zhang F, Wei K, Slowikowski K, Fonseka CY, Rao DA, Kelly S, et al. Defining inflammatory cell states in rheumatoid arthritis joint synovial tissues by integrating single-cell transcriptomics and mass cytometry. Nat Immunol. 2019.

Disclosure of Interests

None declared.

Predictors for influenza vaccine acceptance among patients with inflammatory rheumatic diseases

BACKGROUND

Patients with inflammatory rheumatic diseases are at higher risk for influenza and current guidelines recommend vaccination for this group of patients. The aim of this study was to evaluate the vaccination coverage and predictors for influenza vaccination among patients with inflammatory rheumatic diseases.

METHODS

This survey was conducted at the outpatient rheumatology clinic at the Medical University of Vienna between July and October 2017. All patients diagnosed with an inflammatory rheumatic disease and receiving immunosuppressive therapy were asked to complete a questionnaire about their influenza vaccination status for 2016/17.

RESULTS

490 patients with rheumatic diseases completed a questionnaire (33% male, mean age 55.3 years). The influenza vaccination rate for the previous season was 25.3% (n = 124/490). Predictors for a positive influenza vaccination status were higher age (Adjusted Odds Ratio 5.0, 95% Confidence Interval 2.4-10.4) and treatment with biological disease-modifying antirheumatic drugs (AOR 2.0, 95% CI 1.3-3.1). Patients who received a recommendation for influenza vaccination by their general practitioner were significantly more likely to be vaccinated than those who did not (57% vs. 15%, AOR 6.6, 95% CI 4.1-10.8); even more so if they received a recommendation by their rheumatologist (62% vs. 19%, AOR 9.0, 95% CI 4.9-16.5). The main reasons for patients to decline influenza vaccination were fear of side effects (36%), concerns that vaccination might not be effective due to their immunosuppressed condition (38%) or that it might worsen the rheumatic disease (20%).

CONCLUSIONS

A moderate influenza vaccination rate of 25.3% was detected among patients with inflammatory rheumatic diseases. Recommendation of the influenza vaccine by a physician exerts the most effective impact on a positive vaccination status.

Hydrogen sulphide decreases IL-1β-induced activation of fibroblast-like synoviocytes from patients with osteoarthritis

Balneotherapy employing sulphurous thermal water is still applied to patients suffering from diseases of musculoskeletal system like osteoarthritis (OA) but evidence for its clinical effectiveness is scarce. Since the gasotransmitter hydrogen sulphide (H₂S) seems to affect cells involved in degenerative joint diseases, it was the objective of this study to investigate the effects of exogenous H₂S on fibroblast-like synoviocytes (FLS), which are key players in OA pathogenesis being capable of producing pro-inflammatory cytokines and matrix degrading enzymes. To address this issue primary FLS derived from OA patients were stimulated with IL-1β and treated with the H₂S donor NaHS. Cellular responses were analysed by ELISA, quantitative real-time PCR, phospho-MAPkinase array and Western blotting. Treatment-induced effects on cellular structure and synovial architecture were investigated in three-dimensional extracellular matrix micromasses. NaHS treatment reduced both spontaneous and IL-1β-induced secretion of IL-6, IL-8 and RANTES in different experimental settings. In addition, NaHS treatment reduced the expression of matrix metallo-proteinases MMP-2 and MMP-14. IL-1β induced the phosphorylation of several MAPkinases. NaHS treatment partially reduced IL-1β-induced activation of several MAPK whereas it increased phosphorylation of pro-survival factor Akt1/2. When cultured in spherical micromasses, FLS intentionally established a synovial lining layer-like structure; stimulation with IL-1β altered the architecture of micromasses leading to hyperplasia of the lining layer which was completely inhibited by concomitant exposure to NaHS. These data suggest that H₂S partially antagonizes IL-1β stimulation via selective manipulation of the MAPkinase and the PI3K/Akt pathways which may encourage development of novel drugs for treatment of OA.

Genome-wide association study of systemic sclerosis identifies CD247 as a new susceptibility locus

Systemic sclerosis (SSc) is an autoimmune disease characterized by fibrosis of the skin and internal organs that leads to profound disability and premature death. To identify new SSc susceptibility loci, we conducted the first genome-wide association study in a population of European ancestry including a total of 2,296 individuals with SSc and 5,171 controls. Analysis of 279,621 autosomal SNPs followed by replication testing in an independent case-control set of European ancestry (2,753 individuals with SSc (cases) and 4,569 controls) identified a new susceptibility locus for systemic sclerosis at CD247 (1q22-23, rs2056626, P = 2.09 x 10(-7) in the discovery samples, P = 3.39 x 10(-9) in the combined analysis). Additionally, we confirm and firmly establish the role of the MHC (P = 2.31 x 10(-18)), IRF5 (P = 1.86 x 10(-13)) and STAT4 (P = 3.37 x 10(-9)) gene regions as SSc genetic risk factors.

Clinical, immunological, and immunogenetic aspects of autoantibody production against Ro/SSA, La/SSB and their linear epitopes in primary Sjögren's syndrome (pSS): a European multicentre study

OBJECTIVES

To investigate the clinical and immunogenetic aspects of antibody formation against Ro/SSA and La/SSB as well as their linear B cell epitopes in patients with primary Sjögren's syndrome (pSS) from different European countries.

PATIENTS AND METHODS

Ninety patients with pSS from six European centres were studied. Serum samples from all patients were tested in a control laboratory for anti-Ro/SSA and anti-La/SSB autoantibodies by RNA precipitation assay and autoantibodies to the previously reported B cell linear epitopes of Ro 60 kDa (p169-190aa and p211-232aa) and La/SSB (p147-154aa, p291-302aa, p301-318aa, and p349-364aa). DNA from 88 patients was used for the determination of HLA-DRB1, -DQA1, and -DQB1 genotypes. Analysis of the results was performed in the 88 patients who were genotyped and tested also for antipeptide antibodies.

RESULTS

Antibodies to B cell epitopes of Ro 60 kDa were detected at a low frequency (range 10-37%). In contrast, B cell epitopes of La/SSB were detected frequently (range 58-86%) among the anti-La/SSB positive sera. Autoantibodies to the La/SSB epitope, p349-364aa, were significantly positively associated with longer disease duration (p<0.05), recurrent or permanent parotid gland enlargement (p<0.005), and a higher proportion of non-exocrine manifestations (p<0.005), compared with patients without autoantibodies. The presence of anti-Ro/SSA and anti-La/SSB autoantibodies was significantly associated with the presence of HLA-DRB1*03 and DQB1*02 (p=0.038 and p=0.034, respectively). This association was even more prominent and extended to HLA-DQA1*0501 when patients were stratified according the presence of autoantibodies to discrete La/SSB B cell epitopes in comparison with autoantibody negative patients (p<0.01). They were found also to be highly associated with the alleles HLA-DQB1*02 and HLA-DQA1*0501 as well as the presence of a shared amino acid motif in the region 59-69aa of DQB1 first domain (p<0.01, respectively).

CONCLUSIONS

Autoantibodies against La/SSB, binding to four synthetic peptides, derived from the sequence of the La protein were identified with increased frequency in sera of patients with pSS. The formation of autoantibodies against B cell epitope analogues of La/SSB in European patients with pSS may be dependent on the presence of a permissive HLA-DQ heterodimer, most prominently represented by the HLA-DQA1*0501/DQB1*0201 heterodimer, suggesting that a model of HLA restricted presentation of La/SSB peptide determinants is crucial for the autoimmune response against La/SSB.

Expression of adhesion molecules on synovial fluid and peripheral blood monocytes in patients with inflammatory joint disease and osteoarthritis

OBJECTIVE

To determine the presence of adhesion molecules on monocytes/macrophages (Mphi) from peripheral blood (PB) and synovial fluid (SF) in patients with osteoarthritis (OA) and inflammatory joint diseases (rheumatoid (RA) and reactive arthritis (ReA)) in order to improve our understanding of the possible mechanisms underlying the inflammatory process.

METHODS

Whole blood and SF cells were stained with monoclonal antibodies against CD11a (LFA-1), CD15 s (sialyl-Lewis X), CD44, CD54, VLA-4, and HLA-DR counterstained with anti-CD14 antibodies as a Mphi marker for dual fluorescence analysis by flowcytometry.

RESULTS

On PB-Mphi, CD15s was markedly increased in both RA as well as ReA compared with OA. Furthermore, in the PB LFA-1, CD44, and HLA-DR showed a higher surface density on Mphi in ReA than in OA. Comparison between SF and PB showed significantly higher CD44 and CD54 expression on SF-Mphi. These molecules play an important part in lymphocyte-Mphi interaction.

CONCLUSION

In PB from patients with inflammatory joint diseases, Mphi are activated, allowing recruitment into the synovial compartment. These disorders, in contrast with OA seem to be "systemic" in nature. Within the SF, different adhesion molecules are expressed on CD14(+) Mphi as compared with PB.

Enhanced expression of heat shock protein 70 (hsp70) and heat shock factor 1 (HSF1) activation in rheumatoid arthritis synovial tissue. Differential regulation of hsp70 expression and hsf1 activation in synovial fibroblasts by proinflammatory cytokines, shear stress, and antiinflammatory drugs

Heat shock proteins (hsp) have been repeatedly implicated to participate in the pathogenesis of rheumatoid arthritis (RA). Herein, we investigated the regulation of synovial hsp70 expression by analyzing the DNA-binding activity of heat shock transcription factor 1 (HSF1) as well as inducible hsp70 expression. Experiments were performed both on synovial tissue and on synovial fibroblast-like cells (SFC). Gel mobility shift analysis revealed increased HSF1 activation, and Western blotting and immunohistochemistry revealed increased hsp70 expression in RA synovial tissue, but not in synovial tissue derived from patients with osteoarthritis. Proinflammatory cytokines (TNF-alpha, IL-1alpha, IL-6), but not IFN-gamma or TGF-beta, induced activation of HSF1-DNA binding and hsp70 expression in cultivated SFC. Activation of HSF1 in SFC was accompanied by hyperphosphorylation and nuclear translocation of HSF1. Furthermore, shear stress also induced a complete heat shock response in cultivated synovial cells. In contrast, nonsteroidal antiinflammatory drugs triggered only an incomplete heat shock response, with HSF1 activation but not hsp70 induction, whereas steroids and immunosuppressive drugs did not affect the heat shock response at all. In summary, these data suggest that induction of hsp70 expression in rheumatoid synovial tissue is based on transcriptional activation of HSF1 due to the presence of proinflammatory cytokines (and possibly also shear stress).

Salmon calcitonin and calcium in the treatment of male osteoporosis: the effect on bone mineral density

OBJECTIVE

To assess the effectiveness of salmon calcitonin in the therapy of male osteoporosis.

METHODS

Nine male patients aged 20-73 years with vertebral osteoporosis were included in this study. Patients were prescribed 100 units of salmon calcitonin injected subcutaneously three times per week over a period of three months, followed by three months without salmon calcitonin treatment. Thereafter the patients received another salmon calcitonin cycle for three months as described above. All men received calcium supplementation of 1000 mg/day throughout the study period of 12 months. Bone mineral density of the lumbar spine and at the hip was measured at the beginning and the end of the treatment period using DXA (n = 7) or QCT (n = 2).

RESULTS

Baseline evaluation revealed a bone mineral density of the lumbar spine of 0.78 +/- 0.09 g/cm2 and 0.62 +/- 0.09 g/cm2 at the hip. Treatment with salmon calcitonin resulted in a significant increase of vertebral bone mineral density to 0.80 +/- 0.09 g/cm2 (p < 0.015). Femoral bone mineral density also significantly increased after salmon calcitonin therapy to 0.64 +/- 0.11 g/cm2 (p < 0.05).

CONCLUSION

These results show that calcium and salmon calcitonin increase bone mineral density in male patients with osteoporosis. Calcium and calcitonin may be useful in the treatment of male osteoporosis; however, further studies are necessary before definite recommendations can be made.

Destructive lymphadenopathy and T-lymphocyte activation in adult-onset Still's disease

Recurrent arthritis, fever and lymphadenopathy are symptoms of adult onset of Still's disease (AOSD). Differential diagnosis requires the exclusion of infections or malignant lymphomas. We report on a case of AOSD showing destructive lymphadenopathy, immunophenotyping of peripheral blood leucocytes revealed strong activation of T-lymphocytes. Bone marrow biopsy also showed an increase of lymphopoietic cells to 23%. Analysis of peripheral blood lymphocytes (PBL) after remission showed no remaining signs of activation. Analysis of lymphocyte activation by flow cytometry correlated with disease activity.

Purification of human basophils and mast cells by multistep separation technique and mAb to CDw17 and CD117/c-kit

Basophils and mast cells represent distinct cell lineages within the hemopoietic system. Based on the unique cell surface antigen profile of both cells, we have established methods which allow the reproducible purification to homogeneity (> 99%) of normal human basophil granulocytes from the peripheral blood and of mast cells from human dispersed tissues. Basophils (n = 9) were purified by current counterflow elutriation followed by depletion of monocytes with CD14 mAb conjugated to magnetic beads, and subsequent cell sorting for CD217+ cells. Basophil purity was 99.5 +/- 0.4% (range 98.7-99.9%). Mast cells were obtained from lung (n = 6), uterus (n = 1), mastocytosis bone marrow (n = 2), and human foreskin (n = 2). Mast cells were purified by collagenase digestion followed by current counterflow elutriation and sorting with CD117/c-kit mAb. Mast cell purity was 99.4 +/- 0.7% (range: 97.5-99.9%). Purified cells were more than 90% viable and were able to release histamine on induction with IgE plus anti-IgE. Furthermore, the PCR technique could be applied on pure cells and confirmed expression of high affinity IgE receptor (Fc epsilon R1) alpha chain mRNA. Thus, by combining isolation techniques including elutriation, magnetic cell depletion and cell sorting with mAb, functionally intact normal human basophils and mast cells can be enriched to homogeneity.

Differential expression of the protooncogene bcl-2 in normal and osteoarthritic human articular cartilage

OBJECTIVE

To investigate the expression of bcl-2 in healthy and osteoarthritic articular cartilage at the transcriptional level and at the protein level.

METHODS

bcl-2 mRNA was detected by reverse transcriptase/polymerase chain reaction. The expression of bcl-2 protein was studied using flow cytometry analysis with a monoclonal antibody against intracellular bcl-2 and by immunohistochemistry.

RESULTS

mRNA for bcl-2 was detectable in chondrocytes of both healthy and osteoarthritic cartilage. bcl-2 protein was present in the chondrocytes of the middle layer of cartilage by immunohistochemical staining. In osteoarthritis (OA), chondrocytes adjacent to cartilage defects expressed a particularly high signal intensity. Flow cytometry analysis demonstrated the presence of bcl-2 protein in virtually all chondrocytes.

CONCLUSION

Our results show that bcl-2 is expressed in healthy adult and osteoarthritic human cartilage. The increased staining of chondrocytes adjacent to osteoarthritic defects indicates a differential regulation of programmed cell death during the degenerative process in OA.

High levels of bcl-2 protein in circulating T lymphocytes, but not B lymphocytes, of patients with systemic lupus erythematosus

OBJECTIVE

Defective regulation of programmed cell death (apoptosis) may play a role in the development of autoimmune diseases, and the proto-oncogene bcl-2 is involved in the control of apoptosis in immunocompetent cells. We therefore wished to investigate the expression of bcl-2 in the peripheral lymphocytes of patients with systemic lupus erythematosus (SLE), a prototypical autoimmune disease.

METHODS

Levels of bcl-2 expression in the lymphocytes of patients with SLE and, for comparison, in the lymphocytes of healthy controls and patients with rheumatoid arthritis (RA), systemic bacterial infections, and chronic B cell lymphocytic leukemia were studied by 2-color cytofluorography and RNA analysis.

RESULTS

In SLE patients, a significant proportion of T cells expressed increased amounts of bcl-2 protein. By fluorescence-activated cell sorter analysis, bcl-2--enriched lymphocytes were found in the CD45RO+ as well as in the CD45RO-, and also in the CD4+ and CD8+, lymphocyte subpopulations. Mononuclear cells of patients with SLE showed increased amounts of bcl-2 messenger RNA. An increased percentage of strongly bcl-2 positive peripheral T lymphocytes was found in patients with bacterial infections, but not in those with RA.

CONCLUSION

Although the occurrence of circulating T lymphocytes with abnormally high bcl-2 expression is not specific for SLE, it is evidence for a dysregulation of lymphocytic programmed cell death in this autoimmune disease.

Increased levels of circulating intercellular adhesion molecule-1 in patients with systemic sclerosis

OBJECTIVE

To determine the value of the circulating intercellular adhesion molecule (cICAM-1) as a marker for the inflammatory and fibrotic processes in systemic sclerosis (SSc).

METHODS

We determined serum levels of cICAM-1 and of the soluble interleukin-2 receptor (sIL-2R) by an enzyme-linked immunosorbent assay in 33 patients with SSc. These values were compared to the concentrations of acute phase reactants and to the extent of skin involvement in diffuse and limited scleroderma.

RESULTS

cICAM-1 was elevated in patients with diffuse SSc (498 +/- 134 ng/ml) as compared with 82 healthy controls (312 +/- 71 ng/ml) (mean +/- SD, p < 0.0001). The elevation of cICAM-1 did not correlate with the duration of disease, the pattern of organ manifestations or the type of treatment. While the concentrations of acute phase proteins were not elevated in SSc, a significant correlation between increased serum sIL-2R and cICAM-1 was observed.

CONCLUSION

Increased levels of cICAM-1 indicate an activation of immune processes in SSc. The clinical value of the cICAM-1 determination in SSc can only be judged in longitudinal studies.

High incidence of asymptomatic urogenital infection in patients with uveitis anterior

Acute anterior uveitis (AAU) may be associated with systemic infectious or inflammatory disease. We examined 92 patients with the first attack of acute anterior uveitis; all patients were free of any extraocular symptoms. A thorough clinical examination did not reveal any systemic underlying disease. In the course of microbiological examination, however, a high incidence of asymptomatic infection of the urethra and/or cervix with ureaplasma urealyticum, chlamydia trachomatis and mycoplasma hominis was found. Infections with ureaplasma were significantly more frequent in patients with AAU when compared with a sex- and age-matched control group. There was no statistically valid association of these infections with the HLA-B27 phenotype in the patients. The higher rate of urogenital infections in patients with AAU may reflect a higher rate of sexual promiscuity. Transmission of infectious agents seems to be one possible factor in the pathogenesis of AAU.