Priming of the neutrophil NADPH oxidase activation: role of p47phox phosphorylation and NOX2 mobilization to the plasma membrane

Neutrophils play an essential role in host defense against microbial pathogens and in the inflammatory reaction. Upon activation, neutrophils produce superoxide anion (O*2), which generates other reactive oxygen species (ROS) such as hydrogen peroxide (H2O2), hydroxyl radical (OH*) and hypochlorous acid (HOCl), together with microbicidal peptides and proteases. The enzyme responsible for O2* production is called the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase or respiratory burst oxidase. This multicomponent enzyme system is composed of two trans-membrane proteins (p22phox and gp91phox/NOX2, which form the cytochrome b558), three cytosolic proteins (p47phox, p67phox, p40phox) and a GTPase (Rac1 or Rac2), which assemble at membrane sites upon cell activation. NADPH oxidase activation in phagocytes can be induced by a large number of soluble and particulate factors. Three major events accompany NAPDH oxidase activation: (1) protein phosphorylation, (2) GTPase activation, and (3) translocation of cytosolic components to the plasma membrane to form the active enzyme. Actually, the neutrophil NADPH oxidase exists in different states: resting, primed, activated, or inactivated. The resting state is found in circulating blood neutrophils. The primed state can be induced by neutrophil adhesion, pro-inflammatory cytokines, lipopolysaccharide, and other agents and has been characterized as a "ready to go" state, which results in a faster and higher response upon exposure to a second stimulus. The active state is found at the inflammatory or infection site. Activation is induced by the pathogen itself or by pathogen-derived formylated peptides and other agents. Finally, inactivation of NADPH oxidase is induced by anti-inflammatory agents to limit inflammation. Priming is a "double-edged sword" process as it contributes to a rapid and efficient elimination of the pathogens but can also induce the generation of large quantities of toxic ROS by hyperactivation of the NADPH oxidase, which can damage surrounding tissues and participate to inflammation. In order to avoid extensive damage to host tissues, NADPH oxidase priming and activation must be tightly regulated. In this review, we will discuss some of the mechanisms of NADPH oxidase priming in neutrophils and the relevance of this process to physiology and pathology.     

大鼠心肌梗死后心肌NADPH氧化酶亚单位p22phox的表达

目的：探讨心肌梗死大鼠心室重塑与还原型烟酰胺腺嘌呤二核苷酸磷酸（NADPH）氧化酶亚单位p22phox和超氧阴离子的关系。 方法： Sprague-Dawley大鼠冠脉左前降支结扎复制心肌梗死模型，8周后，心脏超声、血流动力学、心脏形态学方法检测分析心室重塑，检测血浆和非梗死心肌脂质过氧化物的浓度。用RT-PCR和免疫组化方法检测p22phox mRNA水平和蛋白水平的分布。用激光共聚焦方法检测心肌超氧阴离子分布。 结果： 心肌梗死后大鼠心室重塑过程显著，与正常对照组比较，左室舒张末压、左室舒张末径［(3.09±1.52 vs 18.24±6.58)mmHg，(0.67±0.06 vs 0.90±0.15)mm, P<0.01］和脂质过氧化物水平在血浆和非梗死心肌均显著大于正常对照组(P<0.05)。p22phox mRNA和蛋白表达以及超氧阴离子分布在梗死和非梗死心肌亦均显著增加。 结论： 大鼠心肌梗死后，NADPH氧化酶表达增高，其来源的超氧阴离子可能通过氧化应激参加心室重塑过程。     

类风湿关节炎患者血清和关节液细胞因子水平的变化及临床意义

目的探讨幼年类风湿关节炎(JRA)及类风湿关节炎(RA)患者IL-6、IL-8、sIL-2R和TNF-α等细胞因子(CK)水平的变化,及其与风湿活动的传统指标血沉(ESR)和C-反应蛋白(CRP)的相关性。方法采用夹心ELISA法,对30例JRA和34例RA患者的血清中,4例JRA、7例RA、6例骨性关节炎(OA)和9例半月板损伤(MT)患者的关节液中IL-6、IL-8、sIL-2R和TNF-α的水平进行检测。结果①30例JRA、34例RA患者血清IL-6和sIL-2R的水平与对照组相差非常显著(P〈0.01);30例JRA患者血清IL-8水平与对照组比较相差显著(P〈0.05)。②JRA全身型、少关节型患者血清IL-8、sIL-2R的水平和JRA多关节型患者血清IL-6的水平与对照组相差非常显著(P〈0.01)。③4例JRA及7例RA患者关节液sIL-2R的水平和RA患者关节液的IL-6水平与对照组相差显著(P〈0.05)。④JRA患者血清IL-6和sIL-2R的水平与ESR和CRP的变化呈明显的相关关系(r值分别为0.532和0.621)。结论①IL-6、sIL-2R的水平与JRA、RA病的活动性有关,是类风湿活动性的主要指标。②sIL-2R不仅参与JRA和RA的全身病理损伤,而且是引起关节局部损伤的主要CK,IL-6也参与JRA关节局部的病理损伤,在RA关节局部损伤似乎更为重要。③IL-8主要参与JRA的全身病理损伤,对关节局部病理损伤似乎并不重要。     

Lack of T cell oligoclonality in enzyme-digested synovial tissue and in synovial fluid in most patients with rheumatoid arthritis.

The dominant presence of specific T-cell populations in the rheumatoid joint as detected by Southern blot analysis of T cell receptor (TCR) gene rearrangements would indicate local antigen recognition and T cell proliferation. We therefore studied TCR beta chain gene rearrangements using a C beta 2 probe in paired samples of T cell populations from synovial tissue and peripheral blood (n = 6) as well as synovial fluid (n = 16) and peripheral blood (n = 18) of patients with rheumatoid arthritis (RA). Peripheral blood mononuclear cells from healthy donors (n = 7) served as a control. T cells were studied directly after isolation or after non-specific expansion with OKT3 monoclonal antibody (MoAb) and T cell growth factor (TCGF). DNA samples were digested with EcoRI and HindIII to detect rearrangements to C beta 1 and C beta 2, respectively. Extra bands were detected in all EcoRI-digested DNA samples prepared from both freshly isolated and non-specifically expanded T cell populations of patients and healthy donors, possibly representing 'common' (V-) D-J rearrangements. Dominant rearrangements were found in only two out of 16 synovial fluid T cell populations (one freshly isolated and one expanded) and not in peripheral blood or synovial tissue derived T cell populations. No extra bands were detected in HindIII-digested DNA samples. To investigate the effect of in vitro culture techniques on rearrangement patterns we studied DNA samples prepared from synovial tissue T cells obtained both by outgrowth from tissue with TCGF or by enzyme digestion and subsequent expansion either with TCGF or with OKT3 MoAb and TCGF. Whereas the latter T cell population yielded 'common' rearrangements, the former T cell populations yielded different dominant rearrangements. These data indicate that oligoclonality of the T cell populations in synovial tissue and synovial fluid of patients with RA is a rare event. The data also show the influence of in vitro culture techniques on the result of TCR gene rearrangement analysis.     

Genetic and molecular findings of 38 Iranian patients with chronic granulomatous disease caused by p47‐phox defect

One of the components of NADPH oxidase is p47‐phox, encoded by NCF1 gene. This study aims to find new genetic changes and clinical features in 38 Iranian patients with autosomal recessive chronic granulomatous disease (AR‐CGD) caused by NCF1 gene defect. Patients who had abnormal NBT and DHR‐1,2,3 assay with loss of p47‐phox in Western blotting were included in this study. After recording demographic and clinical data, PCR amplification was performed followed by direct sequencing for all exons and exon‐intron boundaries. The most common form of CGD in Iran was AR‐CGD due to consanguinity marriages. Among patients with AR‐CGD, NCF1 deficiency was found to be more common than other forms. Cutaneous involvements (53%), pulmonary infections (50%) and lymphadenopathy (29%) were more prevalent than other clinical manifestations of CGD. Mutation analysis of NCF1 gene identified five different mutations. Homozygous delta GT deletion (c.75_76delGT) was the most frequent mutation and was detected in more than 63% of families. Six families had a nonsense mutation in exon 7 (c.579G > A). Two novel mutations were found in exon 4 in two families, including a missense mutation (c.328C > T) and a nine‐nucleotide deletion (c.331_339delTGTCCCCAC). Genetic detection of these mutations may result in early diagnosis and prevention of possible complications of the disease. This could be useful for timely decision‐making for haematopoietic stem cell transplantation and for carrier detection as well as prenatal diagnosis of next children in the affected families. Our findings might help to predict outcomes, raise awareness and help effective treatment in these patients.     

Superoxide production and NADPH oxidase expression in human rheumatoid synovial cells: regulation by interleukin-1β and tumour necrosis factor-α

Objectives to evaluate the rheumatoid synovial cell capacity to produce superoxide anion in response to interleukin-1β (IL-1β) and tumour necrosis factor-α (TNF-α), and to study the NADPH oxidase involvement in this production. Material and Methods Synovial cells obtained from 7 rheumatoid arthritis (RA), 5 osteoarthritic (OA) patients, and dermal fibroblasts, were stimulated (i) with IL-1β and TNF-α, or (ii) with specific oxidase activators and inhibitors, before studying superoxide production; we also studied NADPH oxidase mRNAs and protein expression, and p47-phox phosphorylation. Results Constitutive superoxide production by RA cells was increased in comparison to OA cells and dermal fibroblasts, and was stimulated by PMA and ionomycin. This production was increased after cytokine treatment of RA synovial cells. Cytokine-induced superoxide production by RA cells was inhibited by iodonium diphenyl or apocynin, suggesting the involvement of NADPH oxidase. RT-PCR and western blot analysis revealed the presence of p47-phox, gp91-phox and Nox4 in RA and OA cells, and in dermal fibroblasts. P47-phox phosphorylation was enhanced after cytokine-treatment in RA and OA cells, suggesting a PKC-mediated up-regulation of NADPH oxidase. Conclusions NADPH oxidase is involved in the superoxide release by RA synovial cells, constitutively and after cytokine up-regulation. These cells express two different homologues (gp91-phox and Nox4). Received 2 August 2005; returned for revision 12 January 2006; returned for final revision 22 May 2006; accepted by J. Di Battista 9 June 2006     

Tumor necrosis factor priming of peripheral blood neutrophils from rheumatoid arthritis patients

Recently it was shown that tumor necrosis factor- (TNF) receptors on neutrophils may be down-regulated after stimulation with proinflammatory mediators. Since in rheumatoid arthritis neutrophils are likely to encounter these mediators in the circulation, we tested the hypothesis that rheumatoid arthritis neutrophil TNF receptors are down-regulated. Peripheral blood neutrophils from patients with rheumatoid arthritis and healthy subjects were compared with respect to their TNF binding activity and ability to be primed by TNF. There were no differences between rheumatoid arthritis and control neutrophils in receptor-mediated TNF binding, superoxide release in response to agonist, and TNF priming of this respiratory burst or in the ability to degrade cartilagein vitro and TNF priming for increased cartilage damage. It is evident that rheumatoid arthritis blood neutrophils retain the ability to bind TNF and can be primed by TNF for increased oxygen radical production and augmented cartilage damage. These findings further implicate the role of neutrophils in the pathogenesis of arthritis.     

Composition and biological behaviour of immune complexes isolated from synovial fluid of patients with juvenile rheumatoid arthritis (JRA)

Data published from In vitro studies have shown that IgM-rheumatoid factor (RF)-bearing immune complexes possess several biological features that may contribute to their pathogenicity. However, no studies have demonstrated that such complexes exist at sites of inflammation in children with rheumatoid disease. We used two methods of sequential column chromatography to purify immune complexes from synovial fluids of children with JRA. We demonstrate that high molecular weight complexes contain IgM-RF, have not bound C4 in vivo, but activate the classical pathway in vitro. In contrast, complexes which have bound C3 in vivo do not contain IgM- RF and are weak complement activators in vitro.     

Expression of vascular endothelial growth factor by synovial fluid neutrophils in rheumatoid arthritis (RA)

Most of the leucocytes infiltrating rheumatoid synovial fluid (SF) are neutrophils capable of producing a variety of inflammatory mediators known to contribute significantly to the disease process during active RA. In the present study, we investigated the contribution made by SF neutrophils to the elevated levels of vascular endothelial growth factor (VEGF) seen in rheumatoid SF. Rheumatoid SF neutrophils were found to contain significantly larger amounts of both VEGF protein and its mRNA than peripheral blood neutrophils from either RA patients or healthy controls. Levels of cell-associated VEGF were well correlated with free VEGF in SF, which was significantly higher than in SF from osteoarthritis patients. Levels of SF neutrophil-associated VEGF also correlated with RA disease activity and cell surface integrin expression. Thus, SF neutrophil-associated VEGF may be considered an indicator of both local and systemic inflammation of RA, contributing to the neovascularization seen during RA synovitis.     

Depressed degranulation response of synovial fluid polymorphonuclear leucocytes from patients with rheumatoid arthritis to IgG aggregates.

No difference was found between the degranulation responses to FMLP of synovial fluid (SF) polymorphonuclear leucocytes (PMNL), from patients with rheumatoid arthritis (RA), and either paired blood PMNL or blood PMNL from a healthy donor. In contrast, the response of SF PMNL to heat-aggregated IgG was often reduced compared with autologous blood PMNL. Similarly, SF from some (35%) RA patients stimulated degranulation of PMNL but the response of SF-derived PMNL to autologous stimulatory SF was reduced compared with the response of blood PMNL. The stimulatory activity of the SF was removed by sepharose-protein A. These results were taken to suggest that the activity is due to immunoglobulin aggregates and that SF PMNL (from some RA patients) are tachyphylactic to stimulation by immunoglobulin aggregates as measured by degranulation because they have been stimulated by immunoglobulin aggregates in vivo. In other studies the concentration of myeloperoxidase (MPO) was measured enzymically in RA SF and was found to be present in varying amounts. However, only a weak relationship was found between MPO levels and either PMNL numbers or levels of complement-bearing IgG aggregates in SF. It is considered that the relationship between MPO and immunoglobulin aggregates levels is obscured by the presence of a peroxidase inhibitor in the fluids and/or because only aggregates bound to tissue stimulate degranulation in vivo.     

Production of PAF-acether by synovial fluid neutrophils in rheumatoid arthritis

PAF-acether (PAF) is a pro-inflammatory phospholipid molecule potentially involved in the pathogenesis of arthritis. PAF and related metabolites have been isolated in the synovial fluid from patients with arthritis.The aim of this study was to determine PAF production by neutrophils isolated from synovial fluid and blood in patients with rheumatoid arthritis. Blood neutrophils from normal donors were also studied for their capacity to form PAF. Neutrophils were stimulated with the calcium ionophore A23187 (2µM) for 1 to 60min. PAF released in the medium and PAF associated to cells were measured.In synovial fluid neutrophils, PAF production began as soon as 1 min of stimulation (16.1 ± 6.3 pmol per 1 × 10⁶ cells) and reached a maximum at 20min: 29.2 ± 2.8 pmol per 1 × 10⁶ cells (mean ± SEM, n = 5). The amount of PAF released in the supernatant increased with the length of stimulation and was maximal after 30min (33.5%, percentage of released over total PAF, n = 5). After A23187 stimulation, similar amounts of PAF were produced by blood neutrophils from RA and control patients. However, neutrophils isolated from the joint had a lower capacity to produce PAF than blood neutrophils from the same patients.The present results demonstrate the synthesis and release of PAF by synovial fluid neutrophils. They suggest that neutrophils may be the source of PAF locally present in the joint. Newly synthetised PAF could participate in the amplification of the local inflammatory reaction.     

Soluble histocompatibility antigens in synovial fluids of patients with rheumatoid arthritis

Soluble histocompatibility antigens of the class II region have been detected in synovial fluids obtained from patients with rheumatoid arthritis. A capture immunoassay involving two monoclonal antibodies was used; interference by rheumatoid factor, which is a feature of such assays, was overcome by mild pretreatment of fluids with 2-mercaptoethanol. No HLA class II antigen could be detected in matched sera from patients, even when levels were high in synovial fluids. Released HLA-class II material was of high molecular weight (greater than 1000 kD) and was linked to HLA-class I antigen. However, no significant amounts of other common cell surface antigens were detected in the complex, suggesting a preferential release of MHC antigens from cells of the inflamed synovium. Attempts to induce production of similar material from a cell line which expresses HLA class II strongly at the cell surface, by stressing the cells in various ways did not succeed, indicating that release is an active process.     

类风湿性关节炎患者滑膜液中IL-10、IL-12和sFasL含量的检测

为了研究细胞因子和凋亡分子在类风湿性关节炎(RA)发病中的作用,用ELISA法分析了26例RA患者滑膜液和血清中IL-12、IL-10和可溶性FasL(sFasL)的含量。结果表明RA患者滑膜液中IL-12、IL-10含量分别为(419.9±89.2)pg/ml和(187.7±34.5)pg/ml,外周血中这两种细胞因子的含量均较低,分别为(65.3±34.2)pg/ml(IL-12)和(85.0±12.7)pg/ml(IL-10)。滑膜液中sFasL的含量为266pg/ml,明显高于血清含量(36pg/ml)。这一结果提示,RA患者滑膜液中IL-12含量和sFasL增高,这些炎性细胞因子增高可能参与了关节滑膜中的自身反应性T细胞的活化,继而造成免疫损伤。     

Polyreactivity of human IgG Fc-binding phage antibodies constructed from synovial fluid CD38+ B cells of patients with rheumatoid arthritis

Recent data indicate that rheumatoid factors (RFs) that occur in patients with rheumatoid arthritis (RA) are derived from Ig-producing terminally differentiated CD20-, CD38+ plasma cells present in synovial fluids (SFs). Phage antibody display libraries were constructed using CD38+ plasma cells isolated from SFs of two RF-seropositive RA patients. The libraries were enriched for phage antibodies (Phabs) binding to human IgG (HuIgG) Fc fragments and the sequences of their V genes were analysed. These data provided further evidence for an Ag-driven immune response in patients with RA, including expansion of clonally related B cells, selection and isotype switching, all hallmarks of a germinal center reaction. In the present study, the functional characteristics of these HuIgG Fc-binding monoclonal (mo) Phabs were further analysed in order to provide more insight into the specificity of HuIgG Fc-binding Phabs. Remarkably, all HuIgG Fc-binding moPhabs tested (n=48; derived from four different libraries) displayed polyreactivity. Structural analysis of the CDR3 regions revealed characteristic features of polyreactive Igs. Most H chain CDR3 regions harboured tryptophan/tyrosine-rich parts and approximately 60% of the L chain CDR3 regions of both RA patients displayed an identical stretch of amino acids (W/Y-D-S-S). Supportive for a dominant role of VH in specificity, exchange of VL regions with a single VH region yielded moPhabs with similar specificities. All together, the data suggest the presence of an Ag-driven process in the joints of patients with RA, including somatic mutation and clonal selection entailing isotype switching, resulting in the differentiation of B cells into polyreactive RF-secreting plasma cells.     

The levels of soluble granzyme A and B are elevated in plasma and synovial fluid of patients with rheumatoid arthritis (RA).

Cytotoxic cells possess specialized granules which contain perforin and a group of serine proteinases termed granzymes. Granzyme-positive cells have been identified in synovial fluid and tissue of patients with RA, where they may play an important role as mediators of granule-mediated apoptosis, extracellular proteolysis, and cytokine induction. The aim here was to define further the involvement of cytotoxic cells in RA. Plasma and synovial fluid samples from the knee joint were obtained from 31 RA patients. The disease controls included 20 osteoarthritis (OA) patients and 10 reactive arthritis (ReA) patients. A recently developed capture ELISA was used to detect soluble granzymes A and B in all patients. Compared with OA and ReA disease controls, markedly increased levels of soluble granzymes A and B were detected in both plasma and synovial fluid of RA patients (P < 0.00001). When values for soluble granzymes A and B in plasma and synovial fluid were used simultaneously as independent variables, logistic regression analysis indicated that a diagnosis of RA could be predicted correctly in 84% of the RA patients and a diagnosis of non-RA in 90% of the controls. The markedly elevated levels of soluble granzymes A and B in plasma and synovial fluid of RA patients strongly suggest that cytotoxic cells are active participants in the pathogenesis of RA. Moreover, the results suggest that measurement of granzymes may assist the laboratory evaluation of patients with arthritis. Larger studies in patients with early disease may clarify the role of this test system in differential diagnosis.     

B和T淋巴细胞衰减因子(BTLA)在类风湿关节炎滑膜组织的表达

目的:探讨CD28家族共抑制分子B和T淋巴细胞衰减因子在类风湿关节炎(RA)患者滑膜组织内的表达。方法:免疫组化法检测RA患者滑膜组织BTLA的表达;并使用免疫荧光法检测BTLA的细胞定位及分布。结果:免疫组化结果证实,RA患者滑膜组织中有大量的BTLA阳性细胞,形态观察提示这些阳性的细胞主要是淋巴结处的淋巴细胞及巨噬细胞;免疫荧光分析进一步表明这些BTLA+细胞主要为CD3+T细胞及CD68+巨噬细胞,少数CD31+内皮细胞也表达BTLA。此外,对比其他B7家族共刺激分子在滑膜组织中的分布,免疫荧光发现BTLA共表达于B7-H1+,B7-H4+及HVEM+细胞,但不表达于B7-DC+及B7-H3+细胞。结论:关节炎滑膜组织内有大量BTLA阳性细胞,提示BTLA有可能参与并调节了关节炎的病理进程。     

Migration of blood and synovial fluid neutrophils obtained from patients with rheumatoid arthritis.

The unstimulated random migration and the serum-induced chemokinesis of neutrophils obtained from the peripheral blood of patients with rheumatoid arthritis (n = 19) was not different from those of controls (n = 20). However, neutrophils obtained from the joint fluid of rheumatoid patients (n = 10) demonstrated a reduced serum-induced chemokinesis which was correlated with the amount of immune complexes present in the synovial fluid. The chemotactic response of peripheral blood neutrophils from subjects with rheumatoid arthritis taking aspirin (n =11) was increased while that of those rheumatoid subjects not taking aspirin (n = 8) was the same as controls. It is concluded that although there is no impairment of the in vitro migratory capacities of peripheral blood neutrophils obtained from patients with rheumatoid arthritis, neutrophils obtained from synovial fluids exhibit a marked defect in chemokinesis which may be related to the ingestion of immune complexes within the joint space.     

Elevated expression of TAM receptor tyrosine kinase in synovial fluid and synovial tissue of rheumatoid arthritis

To investigate the expression and roles of TAM (Tyro3/Axl/Mer) receptor tyrosine kinases (TK) in synovial fluid and synovial tissue of patients with rheumatoid arthritis (RA). The expression of TAM TKs in the synovial fluid and synovial tissues of RA and osteoarthritis (OA) patients was measured by ELISA and immunohistochemistry. The relationships between soluble TAM TKs (sTAM TKs) levels and the clinical features, laboratory parameters and disease activity were analyzed in RA. The concentrations of sTAM TK in the synovial fluids of RA patients were increased in comparison to those of OA patients. Compared with OA patients, the expression of membrane Tyro3 TK (mTyro3 TK) and mMer TK in RA patient synovial tissue were significantly increased, which may partly explain the possible mechanism of elevated levels of sTAM TK in RA patient synovial fluid. sAxl TK levels were decreased in RA patients under sulfasalazine treatment and elevated in patients under Iguratimod treatment. Furthermore, sTyro3 TK levels were positively correlated with erythrocyte sedimentation rate (ESR) and negatively correlated with white blood cells (WBCs), red blood cells (RBCs), and hemoglobin (HB) in RA patients. The levels of sMer TK were positively associated with disease duration and rheumatoid factor (RF) and negatively correlated with HB, complement 3 (C3), and C4. Taken together, TAM TKs might be involved in RA synovial tissue inflammation.     

Elevated angiogenin levels in synovial fluid from patients with inflammatory arthritis and secretion of angiogenin by cultured synovial fibroblasts

Angiogenesis is a key process in the pathogenesis of inflammatory arthritis. Angiogenin is one of the most potent inducers of neovascularization in experimental models in vivo. To look for evidence that angiogenin is involved in inflammatory joint disease, we examined plasma and synovial fluid (SF) samples from rheumatology patients and synovial fibroblast cell culture supernatants. Angiogenin levels were determined by radioimmunoassay and ELISA. Plasma angiogenin concentrations ranged from 96 to 478 ng/ml, with no significant difference between patients and normal controls. In SF, angiogenin concentrations were significantly higher in patients with acute or chronic synovitis (rheumatoid arthritis (RA): median, 104 ng/ml; range 13-748, n = 14; crystal-induced arthritis (CIA): median, 149 ng/ml; range, 37-616, n = 14, and other chronic inflammatory arthritis: median, 42 ng/ml; range, 15-205; n = 9) than in the 18 patients with osteoarthritis (OA) (median, 20 ng/ml; range 8-116) (P < 0.0001, anova). Angiogenin levels in SF from RA patients in remission with secondary OA were similar to those achieved in primary OA, and decreased in parallel with the resolution of acute gout. Angiogenin protein was released by cultured synovial fibroblasts from OA and RA patients, and reached 1.18 ng/106 cells/day. These data suggest that angiogenin may mediate local inflammation in arthritis via effects on angiogenesis and leucocyte regulation.     

Analysis of the cellular infiltrates and expression of cytokines in synovial tissue from patients with rheumatoid arthritis and reactive arthritis

The cellular infiltrates and cytokine patterns in synovial tissue (ST) from patients with rheumatoid arthritis (RA) and reactive arthritis (ReA) were compared in order to determine the mechanisms responsible for the chronic and destructive course of RA. Since the results could be influenced by differences in disease duration, ST was studied from patients in both early and late stages of the disease. Ten patients had early RA (<1 year), ten long-standing RA (>1 year), six early ReA (<1 year), and five long-standing ReA (>1 year). Histological analysis demonstrated that the scores for infiltration by lymphocytes and plasma cells, and the scores for inflammation, were significantly higher in RA than in ReA. Immunolabelling studies showed that in particular, the scores for infiltration by CD38+ plasma cells, granzyme B+ cells, and interferon-gamma (IFNγ)+ cells were significantly higher in RA than in ReA. The results were independent of the disease duration. The increased number of lymphocytes, plasma cells, and granzyme B+ cells in rheumatoid synovial tissue supports the paradigm that RA is the result of specific immune recognition in the joint and that granzyme B+ cells play an important role in joint destruction. © 1998 John Wiley & Sons, Ltd.