Faculty Bibliography

Classically, osteoarthritis (OA) has been considered a noninflammatory disease. However, the detection of selected inflammatory mediators in osteoarthritic fluid, in the absence of significant inflammatory cell infiltrate, is increasingly appreciated. We sought to identify the inflammatory component in human OA-affected cartilage that may be involved in cartilage damage/destruction. Using Western blot analysis and an antibody to the conserved region of nitric oxide synthase (NOS), we have observed up-regulation of NOS, one of the 'key players' of inflammation, in chondrocytes of OA-affected patients. Remarkably, none of the cartilage samples examined from normal joints demonstrated detectable amounts of this NOS. Western blot analysis using the same alpha-NOS antibody indicated that this NOS from OA-affected cartilage (OA-NOS) was larger in size than (and distinct from) transfected human hepatocyte or murine inducible NOS (iNOS) (150 versus 133 kD) and similar in size to neuronal constitutive NOS (ncNOS). Antibodies specific for iNOS showed binding to murine and human iNOS but not to OA-NOS, endothelial constitutive NOS, or ncNOS. Antibodies specific for ncNOS bound to ncNOS and also to OA-NOS, but not to murine or human iNOS or endothelial constitutive NOS. Incubation of OA cartilage in serum-free medium resulted in spontaneous release, for up to 72 h, of substantial amounts of nitrite (up to approximately 80 microM/100 mg wet tissue), which could be inhibited by at least 80% with various inhibitors of iNOS, including inhibitors of protein synthesis and transcription factor NF-kappa B, but which (unlike murine macrophage iNOS) was not sensitive to hydrocortisone or TGF-beta. Exposure of OA-affected cartilage to interleukin 1 beta, tumor necrosis factor-alpha, and lipopolysaccharide resulted in approximately 20-50% augmentation of nitrite accumulation, which was also sensitive to cycloheximide and pyrrolidine dithiocarbamate. Hence, our data indicate that OA-NOS (based on immunoreactivity and molecular weight) is similar to ncNOS and that it releases nitric oxide, which may contribute to the inflammation and pathogenesis of cartilage destruction in OA

Nitric oxide synthesized by inducible nitric oxide synthase (iNOS) has been implicated as a mediator of inflammation in rheumatic and autoimmune diseases. We report that exposure of lipopolysaccharide-stimulated murine macrophages to therapeutic concentrations of aspirin (IC50 = 3 mM) and hydrocortisone (IC50 = 5 microM) inhibited the expression of iNOS and production of nitrite. In contrast, sodium salicylate (1-3 mM), indomethacin (5-20 microM), and acetaminophen (60-120 microM) had no significant effect on the production of nitrite at pharmacological concentrations. At suprapharmacological concentrations, sodium salicylate (IC50 = 20 mM) significantly inhibited nitrite production. Immunoblot analysis of iNOS expression in the presence of aspirin showed inhibition of iNOS expression (IC50 = 3 mM). Sodium salicylate variably inhibited iNOS expression (0-35%), whereas indomethacin had no effect. Furthermore, there was no significant effect of these nonsteroidal anti-inflammatory drugs on iNOS mRNA expression at pharmacological concentrations. The effect of aspirin was not due to inhibition of cyclooxygenase 2 because both aspirin and indomethacin inhibited prostaglandin E2 synthesis by > 75%. Aspirin and N-acetylimidazole (an effective acetylating agent), but not sodium salicylate or indomethacin, also directly interfered with the catalytic activity of iNOS in cell-free extracts. These studies indicate that the inhibition of iNOS expression and function represents another mechanism of action for aspirin, if not for all aspirin-like drugs. The effects are exerted at the level of translational/posttranslational modification and directly on the catalytic activity of iNOS

The object of this study was to determine the incidence of seropositivity to B. burgdorferi by the commonly available enzyme-linked immunosorbent assay (ELISA) in patients with SLE and other rheumatic diseases and to evaluate immunoblot analysis as a tool to differentiate true from false positive ELISA. Sera were obtained from patients with SLE (n = 35), rheumatoid arthritis (n = 26), seronegative arthritis (n = 28) and Lyme disease (n = 18). Reactivity to B. burgdorferi antigens was analysed by two available diagnostic techniques: ELISA and immunoblot. Correlations were made between seroreactivity to B. burgdorferi and standard serological tests of autoimmunity: antibodies to nuclear antigens, dsDNA, cardiolipin, SSA and SSB. Seroreactivity to B. burgdorferi antigens by the ELISA system was detected in 40% of patients with SLE, 8% of patients with rheumatoid arthritis and 4% with seronegative arthritis. Among patients seropositive by ELISA, immunoblots were negative in all cases. However, eight of 14 patients with rheumatoid arthritis (57%) showed cross-reactivity to multiple borreli antigens. No significant correlations were found between Lyme seropositivity by ELISA and other autoantibodies except IgM rheumatoid factor (r = 0.61, P < 0.01) in patients with rheumatoid arthritis. In conclusion: a positive ELISA for Lyme disease was found in up to 40% of patients with established SLE and also in other rheumatic diseases. However, specific serum antibodies to Borrelia were not confirmed by the more specific immunoblot technique.(ABSTRACT TRUNCATED AT 250 WORDS)

Fourteen patients were enrolled in a placebo-controlled double-blind randomized trial of 8 weeks of treatment for active lupus nephritis. Seven patients received prednisone at a dose of 1 mg kg(minus sign1) day(minus sign1) plus misoprostol at a dose of 200 &mgr;g P.O. Q.I.D.; 7 patients received prednisone plus placebo. The patients included 12 females, 2 males; 3 African-Americans, 3 Asians, 5 Hispanics, and 3 Caucasians. There were no serious side effects associated with prednisone or misoprostol treatment during the 8-week study period. Laboratory measures obtained at baseline, 4, 8, and 12 weeks included complete blood count (CBC), ESR, C reactive protein (CRP), serum creatinine, creatinine clearance, 24-h urine protein excretion, C3, C4, and anti-double stranded DNA (anti-dsDNA). Statistical analysis was conducted assessing change in measures over time in the entire study group by paired t-tests. The effect of treatment on change over time was examined by analysis of covariance. Log transformation of the variables was performed prior to statistical analysis. For the entire study group, the mean levels of ESR, CRP, 24-h protein excretion, C3, C4, and anti-dsDNA were improved at 4, 8, and 12 weeks. The mean ESR at baseline was 70 plus minus 8 compared to 42 plus minus 8 at 12 weeks (p < 0.01). The mean CRP at baseline was 0.6 plus minus 0.2 compared to 0.2 plus minus 0.1 at 12 weeks (p < 0.01). The 24-h protein excretion was 4367 plus minus 769 mg at baseline compared to 2512 plus minus 709 mg at 12 weeks (p = 0.02). The mean C3 at baseline was 40 plus minus 4 mg dl(minus sign1) compared to 60 plus minus 4 mg dl(minus sign1) at 12 weeks (p < 0.01). The mean C4 at baseline was 14 plus minus 1 mg dl(minus sign1) compared to 23 plus minus 2 mg dl(minus sign1) at 12 weeks (p < 0.01). The mean anti-dsDNA at baseline was 4268 plus minus 1780 compared to 316 plus minus 111 at 12 weeks (p < 0.001). The baseline serum creatinine (1.12 plus minus.15 mg dl(minus sign1)) and creatinine clearance (82 plus minus 15 ml min(minus sign1)) were not significantly changed at 12 weeks (1.10 plus minus 0.2 mg dl(minus sign1) and 80 plus minus 17 ml min(minus sign1), respectively). Comparing the misoprostol treatment group to the placebo group, there were no statistically significant differences for ESR, CRP, creatinine, creatinine clearance, 24-h protein excretion, C3, C4, or anti-dsDNA at any time points. However, comparing the misoprostol treatment group at 4 weeks to the placebo group, a more rapid decrease in anti-dsDNA (reduction of 3297 plus minus 2374) was observed in the misoprostol treatment group versus 304 plus minus 409 in the placebo group), as well as lower mean anti-dsDNA levels (464 plus minus 140) in the misoprostol treatment group versus 4118 plus minus 3834 in the placebo group). Also, the C3 and C4 levels at 12 weeks in the misoprostol treatment group (67 plus minus 5 and 27 plus minus 3 mg dl(minus sign1), respectively) were greater than levels in the placebo group (52 plus minus 4 and 19 plus minus 3 mg dl(minus sign1), respectively). The data demonstrate that oral prednisone is effective in reducing proteinuria and improving the biological markers of disease activity (i.e., ESR, CRP, C3, C4, and anti-dsDNA) following short-term treatment of active lupus nephritis. Additionally, the more rapid change in anti-dsDNA levels and superior normalization of complement levels in the treatment group, although not statistically significant, are consistent with a biologic effect of misoprostol on lymphocyte function and the production of a pathogenic autoantibodies