Gene array analysis comparison between rat collagen-induced arthritis and human rheumatoid arthritis.

Collagen-induced arthritis (CIA) is an experimental arthritis model used to study the inflammatory processes in this disease and test potential therapeutics. In order to better characterize this model, we conducted the first comprehensive gene expression analysis of rat CIA. To evaluate how closely the rat model reflects human rheumatoid arthritis (RA), we also analysed gene expression in human RA, using genome-wide Affymetrix gene arrays. By applying multiple strategies, including comparison of the highest induced genes, expression of immunological-associated genes as well as Ingenuity Pathway Analysis (IPA), we were able to compare the two expression profiles. Among the highest induced genes in RA were several B-cell-associated genes, including immunoglobulins, B-cell markers such as CD20, and cytokines and chemokines that act on B cells such as TNFSF13b/BLyS and CXCL13, none of which was upregulated in CIA. The latter was instead characterized by the upregulation of genes expressed primarily in macrophages and dendritic cells. Of the 22 pathways identified as significant in both diseases by IPA, only three (IL6, chemokine signalling and antigen presentation) were present in both settings. We conclude that there are significant differences in the inflammatory mechanisms between human RA and rat CIA, and that genome-wide comparative gene expression analyses are useful tools to evaluate the relevance of animal models to human disease.

Metoclopramide response in patients with early diffuse systemic sclerosis. Effects on esophageal motility abnormalities.

OBJECTIVE: To assess the metoclopramide response in patients with early diffuse systemic sclerosis (dSSc) and the acute effects of intravenous (IV) metoclopramide on the lower esophageal sphincter (LES). METHODS: Twenty-one patients with early dSSc (mean age 41.4 +/- 9.8 yrs., mean disease duration 2.47 +/- 0.75 yrs.) were prospectively evaluated. Six patients with late dSSc (mean age 52.6 +/- 9.1 yrs., mean disease duration 9.5 +/- 2.5 yrs.) were used as control group. All underwent solid-state esophageal manometry at rest and 15 minutes later received 10 mg of metoclopramide in an intravenous single bolus. RESULTS: We found that the mean LES pressures measured by the station pull-through technique significantly increased in both early and late dSSc patients after metoclopramide administration (p < 0.05). While early dSSc patients did improve the mean residual pressures (p < 0.05), late dSSc patients did not (p > 0.05). In the esophageal body (EB), the mean contractions amplitude at 18, 13, 8, and 3 cm above the LES was < 20 mm Hg for both groups. However, peristaltic contraction velocitiy was significantly higher in early dSSc patients (< 0.05) than in that with late dSSc (p > 0.05). Our study did not show any major differences when comparing both groups. No side effects were seen. CONCLUSIONS: The results of our study show that metoclopramide may improve LES pressures in patients with early and late dSS. Metoclopramide improve the mean residual pressure in patients with early dSSc, but not in late dSSc patients. Although esophageal contractions amplitude were significantly improved, they did not achieve a pressure > 20 mm Hg. Because metoclopramide can be used orally, it may mitigate both dysphagia and heartburn.

Factors associated with chloroquine-induced retinopathy in rheumatic diseases.

Antimalarials are very useful drugs in the treatment of various rheumatic diseases. One of their main side effects is ocular toxicity, specifically retinopathy. Our objective was to identify risk factors associated with chloroquine retinopathy. A single, trained evaluator reviewed patient records with rheumatic diseases. They were taking chloroquine and identified by the ophthalmology department as having retinopathy during their routine eye evaluation. These cases were classified according to clinical evaluation, visual fields and fluorangiographic study. Up to four controls were selected for each case, matched by age, gender, diagnosis and similar time on chloroquine. In all, 34 variables were studied, among these: weight, age, disease duration, keratopathy, total cumulative dose (TCD), mean daily dose (MDD), lean body weight adjusted daily dose (LBWDD) and laboratory tests. Descriptive and inferential statistics comparing cases and controls in all patients and subgroup analysis were carried out. Significance was set at the 0.05 level. Odds ratio and 95% confidence intervals were calculated. Sixteen cases of chloroquine retinopathy were identified, eight patients with rheumatoid arthritis (RA), seven with systemic lupus erythematosus (SLE) and one with dermatomyositis. All were female. Mean age was 47.3 +/- 12.2 years; weight 59.5 +/- 10.7 kg; disease duration 12.8 +/- 6.0 years; time on chloroquine 54.1 +/- 27.8 (min-max: 30-197) months. There was a significant difference in the following variables in all patients: MDD 212.3 +/- 52.6 versus 170 +/- 51.3, p = 0.009; and LBWDD 5 +/- 1 versus 4.2 +/- 1.5, p = 0.03, for cases and controls, respectively. In subgroup analysis the MDD remained significantly different (235.5 +/- 45.8 versus 169.7 +/- 46.1, p = 0.004) only in RA, whereas LBWDD was different both in SLE and RA. Keratopathy increased the risk for retinopathy: OR, 95% CI: 5, 1.4-17.6, p = 0.01. In conclusion, in accordance with previous studies, the MDD, LBWDD and keratopathy were risk factors associated with chloroquine retinopathy. Periodic ophthalmologic evaluations are mandatory.