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C H Bridts

Publications and source records attributed to C H Bridts.

At least 37 records · Page 2Linked to original sources

Evaluation of monensin and brefeldin A for flow cytometric determination of interleukin-1 beta, interleukin-6, and tumor necrosis factor-alpha in monocytes.

Flow cytometry has become a powerful technique to measure intracellular cytokine production in lymphocytes and monocytes. Appropriate inhibition of the secretion of the produced cytokines is required for studying intracellular cytokine expression. The aim of this study was to compare the capacity of cytokine secretion inhibitors, monensin and brefeldin A, in order to trap cytokine production (interleukin-1 beta [IL-1beta], IL-6, tumor necrosis factor-alpha [TNF-alpha]) within peripheral blood monocytes. A two-color flow cytometric technique was used to measure intracellular spontaneous and lipopolysaccharide (LPS)-stimulated IL-1beta, IL-6, and TNF-alpha production in monocytes (CD14+) of whole blood cultures. The viability of monensin-treated monocytes was slightly lower than that of brefeldin A-inhibited monocytes, as measured with propidium iodide (PI). The percentage of IL-6 and TNF-alpha-producing monocytes after 8 h of culture without stimulation revealed significant lower values for monensin-treated than for brefeldin A-treated monocytes. The percentages for stimulated cells did not differ. The spontaneous intracellular production in molecules of equivalent soluble fluorochrome units (MESF) of IL-1beta, IL-6, and TNF-alpha after 8 h of culture was higher in brefeldin A than in monensin-inhibited monocytes. The LPS-stimulated intracellular production of IL-1beta, IL-6, and TNF-alpha was increased in brefeldin A-inhibited monocytes. In conclusion, for flow cytometric determination of intracellular monocytic cytokines (IL-1beta, IL-6, and TNF-alpha), brefeldin A is a more potent, effective, and less toxic inhibitor of cytokine secretion than monensin.

Adult↗

Wasp venom immunotherapy induces a shift from IL-4-producing towards interferon-gamma-producing CD4+ and CD8+ T lymphocytes.

BACKGROUND: Venom immunotherapy (VIT) has proven to be very effective in hymenoptera venom anaphylaxis. However, the underlying immunoregulatory mechanisms of venom immunotherapy remain poorly understood. Recent studies measured the total amount of cytokine in culture supernatans, suggesting a shift in cytokine production from Th2 to a Th1 cytokine profile during VIT. We wanted to examine the contribution of specific T lymphocyte subpopulations, which is impossible using an extracellular method to determine cytokines in supernatants. OBJECTIVE: The present study was designed to evaluate the effect of VIT on the percentages of type 1 (IL-2, interferon-gamma (IFN-gamma)) and type 2 (IL-4) CD4+ and CD8+ T lymphocytes of patients with wasp venom anaphylaxis during immunotherapy. METHODS: Peripheral blood mononuclear cells of 20 individuals with a history of wasp sting anaphylaxis and a positive serum wasp venom specific IgE were isolated and in vitro stimulated with phorbol-12-myristate-13-acetate and ionomycin before VIT, at the end of a 5-day semirush VIT and at 6 months during VIT. Three-colour flow cytometric analysis was used for intracellular cytokine (IL-2, IFN-gamma, IL-4) detection in CD4+ (CD3+CD8-) T lymphocytes and CD8+ (CD3+CD8+) T lymphocytes. RESULTS: At the end of a 5-day semirush VIT, there was a significant decrease in percentage of IL-4-producing CD4+ and CD8+ T cells, compared with cytokine-producing cells before VIT (P = 0.0002 and 0.004). After 6 months of VIT, patients showed an increased number of IL-2-producing stimulated CD4+ and CD8+ lymphocytes compared with values before VIT (P = 0.002 and P = 0.0003). A higher amount of IFN-gamma-producing stimulated CD4+ and CD8+ cells was found after 6 months of VIT (P = 0.001 and P = 0.0006). There was no correlation between cytokine-producing cells and specific IgE for wasp. CONCLUSION: Venom immunotherapy induced a shift from IL-4-producing towards IFN-gamma-producing CD4+ as well as CD8+ T lymphocytes.

Adolescent↗

Influence of longterm therapy with methotrexate and low dose corticosteroids on type 1 and type 2 cytokine production in CD4+ and CD8+ T lymphocytes of patients with rheumatoid arthritis.

OBJECTIVE: Rheumatoid arthritis (RA) is a chronic inflammatory disease with predominance of type I cytokine [interleukin 2 (IL-2), interferon-gamma (IFN-gamma)] production. In this prospective study, we evaluated the influence of longterm therapy with methotrexate (MTX) in combination with low dose corticosteroids on the type 1/type 2 cytokine balance in RA. METHODS: Peripheral blood mononuclear cells were isolated from 10 controls and 20 patients with RA before therapy and after 12 mo of therapy with MTX in combination with low dose corticosteroids. Using flow cytometry, the intracellular production of IL-2, IFN-gamma, and IL-4 was measured in CD4+ and CD8+ T lymphocytes. RESULTS: Compared with healthy controls, patients with RA before therapy showed an increased percentage of IL-2 positive CD4+ and CD8+ T cells (p = 0.002, p = 0.01, respectively). An increased percentage of IFN-gamma positive CD8+ T cells was found (p = 0.0006) compared with the control group. After 12 months of therapy, a significantly decreased percentage of IL-2 positive CD4+ T cells and IFN-gamma positive CD4+ and CD8+ T lymphocytes was observed (p = 0.0003, p = 0.0007, p = 0.001). The percentage of IL-4/IFN-gamma positive CD4+ and CD8+ T cells was significantly higher after 12 months of therapy (p = 0.01, p = 0.02). There was a positive correlation between the percentage of IFN-gamma positive CD4+ T cells and disease activity variables (Ritchie Index and number of swollen joints) in RA patients before therapy (r = 0.6, p = 0.04 and r = 0.4, p = 0.05). CONCLUSION: Longterm therapy with MTX in combination with low dose corticosteroids for RA influenced the predominance of type 1 cytokines toward normalization of the cytokine balance in both CD4+ and CD8+ T lymphocytes.

Adrenal Cortex Hormones↗

Determination of T-cell subpopulations and intracellular cytokine production (interleukin-2, interleukin-4, and interferon-gamma) by cord blood T-lymphocytes of neonates from atopic and non-atopic parents.

This report describes the results of a prospective study on immunological markers in cord blood for the prediction of allergic diseases in children. First we evaluated methodological aspects of the flow cytometric technique on cord blood cytokine measurements. Subsequently, the T-cell subsets and percentage of cytokine-producing cord blood T-helper (Th) and T-suppressor/cytotoxic lymphocytes of neonates from atopic and non-atopic parents were compared. A group of 33 healthy, full-term newborn infants of whom 23/33 were at risk for atopy (i.e. having at least one parent with one or more atopic symptoms and positive specific immunoglobulin E [IgE] to at least one common inhalant allergen) was studied. A flow cytometric technique was used to analyze cord blood T-cell subsets and to determine the percentage of interleukin (IL)-2-, IL-4-, and interferon-gamma (IFN-gamma)-producing cord blood Th and T-suppressor/cytotoxic lymphocytes following stimulation with phorbol 12-myristate 13-acetate (PMA) and ionomycin. The percentage of CD3 (T lymphocytes), CD3+ CD4+ (Th lymphocytes), CD3+ CD8+ (T-suppressor/cytotoxic lymphocytes), CD19+ (B lymphocytes), CD3+ CD4+ CD45RO+ (memory Th lymphocytes), and CD3+ CD4+ CD45RA+ (naive Th lymphocytes) cells was unrelated to parental atopic status. PMA stimulation augmented the percentage of IL-2- and IFN-gamma-producing Th and T-suppressor/cytotoxic lymphocytes, whereas the number of IL-4-producing T lymphocytes remained very low or undetectable. No differences in the percentage of TL-2-, IL-4- and IFN-gamma-producing Th and T-suppressor/cytotoxic lymphocytes were found between neonates from atopic and non-atopic parents. These results will be re-evaluated when the atopic status of the children at the age of 1 and 2 years can be assessed.

Animals↗

Influence of blood and synovial fluid immune complexes of patients with rheumatoid arthritis on production of nitric oxide and growth and viability of chondrocytes.

OBJECTIVE: To determine whether blood and synovial fluid (SF) immune complexes (IC) of patients with rheumatoid arthritis (RA) influence the production of nitric oxide (NO) and growth and viability of chondrocytes. METHODS: IC were precipitated and IgM and IgG were determined in the precipitates by ELISA and nephelometry, respectively. Primary cultures of bovine articular chondrocytes were incubated with the IC precipitates. After 48 h NO was determined as nitrite. After 7 days, growth was determined by incorporation of tritiated thymidine and viability was detected by neutral red uptake. RESULTS: Patient sera were positive in 8/12 for IgM IC and 9/12 for IgG IC, and 1/8 control sera was slightly positive for IgM IC. Seven of 12 SF samples were IgM IC and 10/12 IgG IC positive. With and without additional interleukin 1alpha (IL-1alpha) stimulation, NO production by chondrocytes was significantly higher with SF IC precipitates than with control serum precipitates (p = 0.03, p = 0.04, respectively). NO production by chondrocytes that were not stimulated with IL-1alpha was significantly increased with SF IC precipitates compared to RA serum IC precipitates (p = 0.03). SF IC significantly inhibited growth compared to control serum precipitates (p = 0.04) and RA serum IC (p = 0.012). Neutral red uptake by chondrocytes was significantly decreased when incubated with RA serum IC in comparison with control serum IC (p = 0.012) and SF IC (p = 0.006). With and without additional IL-1alpha stimulation, NO production by chondrocytes after incubation with SF derived IC was positively correlated to the Ritchie score (r = 0.8, r = 0.7, respectively) and the number of swollen joints (r = 0.8, r = 0.6, respectively). CONCLUSION: These results support the hypothesis that, especially in active RA, SF derived IC stimulate NO production and inhibit chondrocyte growth.

Antigen-Antibody Complex↗

Flow cytometric detection of type 1 (IL-2, IFN-gamma) and type 2 (IL-4, IL-5) cytokines in T-helper and T-suppressor/cytotoxic cells in rheumatoid arthritis, allergic asthma and atopic dermatitis.

Type 1 cytokines (a.o. IL-2 and IFN-gamma) play an important role in the pathogenesis of rheumatoid arthritis. On the other hand, IgE-mediated diseases such as allergic asthma and atopic dermatitis show a type 2 cytokine (amongst others IL-4 and IL-5) profile. This study examined simultaneously the intracellular production of IL-2, IFN-gamma, IL-4 and IL-5 in T-lymphocytes of patients with rheumatoid arthritis during treatment with methotrexate or salazopyrin, patients with allergic asthma or atopic dermatitis under stable treatment, compared to healthy controls.A three-colour flow cytometric analysis was used for cytokine detection in T-helper cells and T-suppressor/cytotoxic cells. Compared to controls, patients with symptomatic atopic dermatitis showed an increased number of IL-4-producing T-helper lymphocytes in basal circumstances (P=0.001), in contrast to asymptomatic allergic asthma patients. Compared to controls, rheumatoid arthritis patients, treated with salazopyrin, showed an increased number of IL-2-producing T-helper and T-suppressor/cytotoxic lymphocytes after in vitro stimulation with PMA and ionomycin (P=0.01). In contrast, rheumatoid arthritis patients, treated with methotrexate, a more potent disease modifying drug, did not show this type 1 cytokine profile. A positive correlation was found between the number of IFN-gamma producing T-helper cells and disease activity (Ritchie Index and number of swollen joints) in both rheumatoid arthritis patient groups. Active atopic dermatitis patients showed a type 2 cytokine profile, whereas stable asthma patients with lower disease activity did not show a predominance of type 2 cytokines. Rheumatoid arthritis patients under treatment with salazopyrin had a type 1 cytokine profile, which could not be demonstrated in patients treated with methotrexate. This imbalance between type 1 and type 2 cytokines in different immune mediated disorders can be related with treatment and the grade of disease activity. These results stress the need for further investigation of the influence of therapy on cytokine profiles.

Adolescent↗

Flow cytometrical determination of interleukin 1beta, interleukin 6 and tumour necrosis factor alpha in monocytes of rheumatoid arthritis patients; relation with parameters of osteoporosis.

Experimental data suggest that pro-inflammatory cytokines such as interleukin 1beta (IL-1beta), interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-alpha) are important in the pathogenesis of osteoporosis in rheumatoid arthritis. Therefore we compared the production of these cytokines by monocytes in 10 rheumatoid arthritis patients and 10 controls. Cytokine levels in rheumatoid arthritis patients were related to disease activity parameters, bone mineral density (BMD) corrected for age and sex (Z scores) and osteocalcin as a laboratory parameter of bone remodelling. Cytokines were determined by a flow cytometrical technique. There was a tendency for higher IL-1beta levels in patients compared with controls. A positive correlation between erythrocyte sedimentation rate and spontaneous production of monocytic cytokines was found. Z scores of the lumbar spine showed a negative correlation with spontaneous production of IL-1beta and IL-6. Plasma osteocalcin levels were positively correlated with spontaneous production of IL-1beta, IL-6 and TNF-alpha. In conclusion, the correlation of the levels of these cytokines with parameters of bone metabolism and osteoporosis suggest that especially IL-1beta and IL-6 are associated with more pronounced osteoporosis in active rheumatoid arthritis.

Absorptiometry, Photon↗

Evolution of lymphocyte transformation to wasp venom antigen during immunotherapy for wasp venom anaphylaxis.

BACKGROUND: Venom immunotherapy (VIT) has proven to be safe and effective in wasp venom anaphylaxis. However, there are no good parameters to indicate when to stop venom immunotherapy. OBJECTIVE: To evaluate the relationship of the lymphocyte transformation test (LTT) to history and specific IgE determination, and to address the time course of lymphocyte transformation responses to wasp (Vespula) venom during VIT and the possible utility of LTT to determine the duration of therapy. METHODS: Peripheral blood mononuclear cells (PBMCs) of 18 individuals with a history of wasp sting anaphylaxis and a positive serum-venom-specific IgE, were stimulated with wasp venom before immunotherapy, at the end of a 5-day semi-rush immunotherapy and at 24 months during venom immunotherapy. Results, expressed as stimulation index (SI), were compared with the SI in seven asymptomatic stung controls. RESULTS: In controls the median (minimum-maximum) of the SI were 2.39 (0.52-3.39) before therapy and 2.39 (1.12-6.02) when repeated after 24 months. For patients the median (minimum-maximum) of the SI were 10.13 (1.19-44.88) before immunotherapy (d0), 2.73 (0.67-12.03) at the end of the build-up immunotherapy (d5) and 4.21 (0.88-14.66) at the end of 24 months of maintenance therapy (m24). The proliferation responses in vespid-allergic patients were significantly higher than in stung controls (P = 0.006) but only 13/18 patients showed a positive LTT result before the start of immunotherapy (sensitivity of the LTT 72%). When the LTT was repeated after a 5 day build-up hyposensitization course the SI significantly dropped as compared to the pre-treatment levels (P = 0.002). The SI of the LTT was negative in eight out of 18 patients at 24 months and the median values were significantly lower than before therapy (P = 0.03). CONCLUSIONS: Although, in the absence of sting challenge data it is not possible to draw conclusions about the predictive value of the LTT, our data may suggest that abolition of the LTT during VIT might indicate clinical insensitivity. Further studies, comparing the results of sting challenges, with the results of lymphocyte transformation will be necessary in order to evaluate the role of LTT in stopping immunotherapy.

Adolescent↗

Comparison between the in vitro cytokine production of mononuclear cells of young asthmatics with and without immunotherapy (IT)

BACKGROUND: The underlying mechanisms of immunotherapy (IT) are still unknown but may be related to modifications of cytokine production of T lymphocytes. OBJECTIVE: In this study we determined the in vitro allergen-induced production of IL-2, IL-4, IL-5, IL-12 and IFNgamma of peripheral blood mononuclear cells (PBMC) of eight young asthmatics, aged 15+/-2 years, receiving IT (IT group) and of eight comparable asthmatics, aged 13+/-3.5 years, who never received IT (non-IT group). METHODS: All patients suffered from perennial asthma and were allergic to house dust mite (HDM). They were selected if they showed a positive stimulation index (SI) of PBMC after in vitro incubation with HDM (i.e. SI > 2). Cells were incubated with and without HDM (10 microg/mL) during 24 h, 48 h and 7 days. Cytokines were determined in the supernatant at the three time points and are expressed as median values in pg/mL. RESULTS: In the IT group the secretion of IL-2 was lower compared with the non-IT group after 7 days incubation of PBMC with HDM (0 vs 33.2, P = 0.008). In both groups maximal secretion of IL-2 was observed after 48 h. In the non-IT group a high value of IL-2 persisted after 7 days, whereas in the IT group a significant decline of IL-2 occurred after 7 days. Although IL-4 secretion was low in all subjects, more patients of the non-IT group showed detectable IL-4 in the HDM cultures after 24 h and 48 h, although the difference was not statistically significant (P = 0.08 and P = 0.28, respectively). Furthermore, IL-4 secretion was lower in the HDM cultures after 24 h in the IT group (1.75 vs 4.1, P = 0.011) and 48 h (2.2 vs 4.1, P=0.035). IL-5 secretion was lower in the HDM cultures after 24h (12.4 vs 47.6, P = 0.035) and 48 h (26.8 vs 135, P = 0.046) in the IT group than in the non-IT group. After 7 days of incubation with HDM there was no difference between the groups. There was no difference between both groups in secretion of IFNgamma and IL-12. CONCLUSIONS: These results show a difference in vitro cytokine secretion of PBMC of asthmatics receiving IT compared with asthmatics who never received IT. PBMC of patients receiving IT secrete less IL-2 and IL-5 after in vitro incubation with HDM and show a tendency to secrete less IL-4. The efficacy of IT may be attributed to a modified cytokine secretion of PBMC.

Allergens↗

Influence of antirheumatic drugs on nitric oxide and interleukin 8 production in human articular chondrocytes.

OBJECTIVE: To determine whether antirheumatic drugs can inhibit chondrocyte nitric oxide and interleukin 8 (IL-8) production. METHODS: IL-1beta stimulated human chondrocytes were incubated with indomethacin, methotrexate, sulfasalazine, dexamethasone, and methylprednisolone. Nitric oxide was detected as nitrite; IL-8 was detected by a radioimmunoassay method. RESULTS: Nitric oxide production was partly (< or = 50%) inhibited and IL-8 almost completely suppressed (> 80%) by dexamethasone and methylprednisolone. Sulfasalazine in pharmacological concentration and indomethacin slightly increased IL-8. No effect of methotrexate on nitric oxide or IL-8 production was found. CONCLUSION: Dexamethasone and methylprednisolone are inhibitors of human chondrocyte nitric oxide production, although to a lesser extent than for IL-8 production. Indomethacin, sulfasalazine, and methotrexate had no major influence on these mediators.

Antirheumatic Agents↗

Actin polymerisation in neutrophils of rheumatoid arthritis patients in relation to treatment with non-steroidal anti-inflammatory drugs.

There is evidence that neutrophil functions such as chemotaxis and oxygen radical formation are disturbed in rheumatoid arthritis (RA). Medication might also influence these functions. Cyclic formation and depolymerisation of actin microfilaments is crucial in cell motility, but this phenomenon has not been studied in RA. The aim of this study was to investigate basal and dynamic (formyl-methionyl-leucyl-phenylalanine (fMLP)-induced) neutrophil actin polymerisation in ten RA patients (a) during therapy with non-steroidal anti-inflammatory drugs (NSAIDS) and (b) after stopping NSAIDS> The results were compared with those of ten age-matched controls. Basal F-actin content in RA patients with NSAIDS was significantly lower than in RA patients without NSAIDS and controls: 35.5 (25.0-49.0), 50.5 (27.0-75.0) and 52.5 (32.0-85.0), respectively. Conversely, upon stimulation with fMLP, the actin polymerisation curve of RA patients with NSAIDS was higher than for RA patients without NSAIDS and controls. These results suggest that, in RA, the effects orf NSAIDS on neutrophil functions might be related to changes in the actin polymerisation-depolymerisation cycle.

Actins↗

Latex-specific IgE, skin testing, and lymphocyte transformation to latex in latex allergy.

BACKGROUND: This study was designed to determine the discriminative value of latex-specific IgE tests, latex skin tests, and lymphocyte transformation tests (LTTs) to latex in 38 patients with latex allergy (12 nonatopic and 26 atopic) and 44 control subjects (24 nonatopic and 20 atopic). We also evaluated the recommended positive cutoff (i.e., 0.35 kU/L) of both in vitro latex-IgE tests. METHODS: Latex-specific IgE levels were determined by the Immuno-CAP (Upjohn-Pharmacia) and the ALaSTAT-RIA (Diagnostic Products Corp.) assays. Skin tests and LTFs were performed with a nonammoniated latex extract (DPC). Sensitivities and specificities were defined according to the 95th percentile value of nonatopic control subjects. For the in vitro IgE tests, sensitivity and specificity were also calculated by using the proposed positive threshold of 0.35 kU/L. Sensitivities and specificities of both cutoffs were compared. RESULTS: Compared with a clinical history of latex allergy and according to the 95th percentile value of nonatopic control subjects (0.44 kU/L), latex-specific IgE determined by the Immuno-CAP assay achieved a sensitivity of 97% and a specificity of 86%. For the ALaSTAT-RIA assay, with 0.54 kU/L as the 95th percentile threshold value in nonatopic control subjects, sensitivity was 100%, and specificity was 83%. According to the threshold value of 0.35 kU/L, a sensitivity of 97% and a specificity of 83% for the Immuno-CAP assay and a sensitivity of 100% and a specificity of 33% for the ALaSTAT-RIA assay were observed. The latex skin test reached a sensitivity of 97% and a specificity of 100%. The LTF to latex showed a sensitivity of 39% and a specificity of 95%. No relation between symptoms and latex-specific IgE tests, latex skin tests, or LTTs was found. CONCLUSIONS: Our results confirm that latex skin tests and latex-specific IgE assessments are sensitive and specific methods for establishing the diagnosis of latex allergy, although the specificity of the ALaSTAT-RIA assay was very low when interpreted according to the threshold of 0.35 kU/L. The LTT to nonammoniated latex is too insensitive for diagnosis of allergy to latex. This reemphasizes that in order to evaluate the sensitivity and specificity of diagnostic procedures, one should always include an appropriate control group.

Adolescent↗

Anti-neutrophil cytoplasmic antibodies in inflammatory bowel disease with special attention for IgA-class antibodies.

Perinuclear anti-neutrophil cytoplasmic antibodies (P-ANCA) of the IgG class have been reported in inflammatory bowel disease, mainly in ulcerative colitis. Since this disease affects the gastrointestinal tract, we determined whether IgA class ANCA were present in inflammatory bowel disease. We used an indirect immunofluorescence assay for IgG and IgA ANCA testing. Sera from 34 patients with Crohn's disease and 29 patients with ulcerative colitis were collected together with clinical and laboratory data. We found IgA class ANCA of a perinuclear type in 52% of patients with ulcerative colitis and in 9% of Crohn's disease patients. There was a significant association between the presence of IgA ANCA and the occurrence of blood in the feces in the ulcerative colitis group (P = 0.03). IgG ANCA was found in 56% of patients with ulcerative colitis and in 7% of patients with Crohn's disease. Because of partial overlap between IgG and IgA ANCA positivity, the sensitivity of ANCA testing in ulcerative colitis increased from 56% up to 78% by combining IgG and IgA assays. In conclusion, IgA ANCA occurs with a high prevalence in ulcerative colitis. Moreover there is a possible relationship between IgA ANCA and disease activity in ulcerative colitis.

Adult↗

Anticardiolipin, anti-beta(2)-glycoprotein I, antiprothrombin antibodies, and lupus anticoagulant in patients with systemic lupus erythematosus with a history of thrombosis.

OBJECTIVE: To determine the clinical importance of anticardiolipin (aCL), anti-beta(2)-glycoprotein I (a beta(2)-GPI), antiprothrombin (aPT), and lupus anticoagulant (LAC) antibodies in patients with systemic lupus erythematosis (SLE) with and without a history of thrombosis. METHODS: We studied 100 patients with SLE (32 with a history of thrombosis), 27 patients with a lupus-like disease (9 with a history of thrombosis), and 41 healthy volunteers, IgG and IgM aCL, antibodies to the protein cofactors (a beta(2)-GPI and aPT) were determined by ELISA. Eighty-six of 127 patients were also tested for LAC. RESULTS: IgG aCL and LAC were associated with thrombosis but sensitivity (63 and 61%) and specificity (66 and 66%, respectively) of these tests were low. IgG and IgM a beta(2)-GPI were, respectively, 85 and 86% specific for a thrombotic history, but sensitivity was very low (32 and 29%). High IgG aCL were associated with the presence of a beta(2)-GPI and were 85% specific for thrombosis. There was no significant association between IgG or IgM aPT and thrombosis. CONCLUSION: Only high levels of IgG aCL and presence of LAC and/or a beta(2)-GPI are relevant in defining a thrombotic subset of patients with SLE. Longitudinal prospective studies are needed to investigate the predictive value of the different antiphospholipid and protein cofactor antibodies.

Adult↗

Relationship between interleukin-8 and neutrophil adhesion molecules in rheumatoid arthritis.

To evaluate the role of interleukin-8 (IL-8) on the activation of neutrophils in rheumatoid arthritis (RA), we measured IL-8 and the adhesion molecules, L-selectin (CD62L), CD1 1b and CD18, on neutrophils in paired peripheral blood and synovial fluid of RA patients. Synovial fluid IL-8 levels were significantly increased compared to peripheral blood. L-selectin was split off and CD1 1b and CD 18 were upregulated on neutrophils in the synovial fluid. A positive correlation occurred between the IL-8 concentration and CD18 or CD1 1b densities on neutrophils in the synovial fluid (r = 0.75, P < 0.005 and r = 0.60, P < 0.05, respectively). Peripheral blood neutrophils of the patients were desensitised with IL-8 in vivo, as shown by the significantly lower L-selectin shedding after in vitro IL-8 stimulation: 1.6 times decrease for patients vs 3.2 for controls (P < 0.05). In conclusion, these results add further evidence for the role of IL-8 in the activation of neutrophils in RA.

Adult↗