Rheumatoid Arthritis: Chibnik LB

Benito-Garcia E, Heller JE, Chibnik LB, Maher NE, Matthews HM, Bilics JA, Weinblatt ME, Shadick NA. · Division of Rheumatology, Immunology and Allergy, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA. · J Rheumatol. · Pubmed #16821266 No free full text.

Abstract: OBJECTIVE: Methylxanthines, like caffeine, have been thought to reverse the antiinflammatory effects of methotrexate (MTX) in rheumatoid arthritis (RA). We investigated whether patients with RA taking MTX with a higher dietary caffeine intake have a worse clinical response to MTX than those with a lower intake. METHODS: Patients with RA enrolled in a prospective cohort study and currently taking MTX were divided equally into low, moderate, and high caffeine consumers. MTX clinical response was defined by the Disease Activity Score (DAS)28, Multidimensional Health Assessment Questionnaire (MDHAQ) score, and duration of morning stiffness. Regression models were used to study the relationship between caffeine intake and MTX response adjusting for age, sex, and other relevant variables at study enrollment. RESULTS: Two hundred and sixty-four patients with RA taking MTX had an average caffeine intake of 211.7 mg and average MTX dose of 16.0 mg/wk. The low caffeine group comprised 87 patients, the moderate 86, and the high 91. In 3 multivariate models, there was no statistical difference in MTX efficacy between groups, as measured by DAS28 score, MDHAQ score, and duration of morning stiffness at study enrollment. Moderate and high caffeine group had higher DAS28 scores, physician's global assessment, and swollen joint counts, but differences were not significant. CONCLUSION: Caffeine intake among patients taking high doses of MTX for RA did not affect MTX efficacy and RA disease activity over time.

Karlson EW, Chibnik LB, McGrath M, Chang SC, Keenan BT, Costenbader KH, Fraser PA, Tworoger S, Hankinson SE, Lee IM, Buring J, De Vivo I. · Division of Rheumatology, Immunology, and Allergy, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA. · Arthritis Res Ther. · Pubmed #19555469 links to  free full text

Abstract: INTRODUCTION: Rheumatoid arthritis (RA) is more common in females than males and sex steroid hormones may in part explain this difference. We conducted a case-control study nested within two prospective studies to determine the associations between plasma steroid hormones measured prior to RA onset and polymorphisms in the androgen receptor (AR), estrogen receptor 2 (ESR2), aromatase (CYP19) and progesterone receptor (PGR) genes and RA risk. METHODS: We genotyped AR, ESR2, CYP19, PGR SNPs and the AR CAG repeat in RA case-control studies nested within the Nurses' Health Study (NHS), NHS II (449 RA cases, 449 controls) and the Women's Health Study (72 cases, and 202 controls). All controls were matched on cohort, age, Caucasian race, menopausal status, and postmenopausal hormone use. We measured plasma dehydroepiandrosterone sulfate (DHEAS), testosterone, and sex hormone binding globulin in 132 pre-RA samples and 396 matched controls in the NHS cohorts. We used conditional logistic regression models adjusted for potential confounders to assess RA risk. RESULTS: Mean age of RA diagnosis was 55 years in both cohorts; 58% of cases were rheumatoid factor positive at diagnosis. There was no significant association between plasma DHEAS, total testosterone, or calculated free testosterone and risk of future RA. There was no association between individual variants or haplotypes in any of the genes and RA or seropositive RA, nor any association for the AR CAG repeat. CONCLUSIONS: Steroid hormone levels measured at a single time point prior to RA onset were not associated with RA risk in this study. Our findings do not suggest that androgens or the AR, ESR2, PGR, and CYP19 genes are important to RA risk in women.

Karlson EW, Chibnik LB, Tworoger SS, Lee IM, Buring JE, Shadick NA, Manson JE, Costenbader KH. · Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA. · Arthritis Rheum. · Pubmed #19248103 No free full text.

Abstract: OBJECTIVE: To examine the association of biomarkers of inflammation with preclinical rheumatoid arthritis (RA). METHODS: A nested case-control study was performed using samples from 2 large, prospectively studied cohorts of women (the Women's Health Study [WHS] and the Nurses' Health Study [NHS]). Blood samples obtained prior to symptom onset in women who later developed RA were selected as incident RA cases, and 3 controls per case were randomly chosen, matched for age, menopausal status, postmenopausal hormone use, and day, time, and fasting status at the time of collection. Plasma was tested for levels of interleukin-6 (IL-6), soluble tumor necrosis factor receptor II (sTNFRII) (as a proxy for TNFalpha), and high-sensitivity C-reactive protein. Relationships between biomarkers and RA were assessed using conditional logistic regression models, adjusting for age, body mass index, smoking habits, ethnicity, and reproductive factors. RESULTS: In 93 incident cases in the NHS and 77 incident cases in the WHS, the mean time between blood collection and the onset of RA symptoms was 5.2 years (range 0.3-12 years). Median IL-6 and sTNFRII levels were significantly higher in preclinical RA cases compared with matched controls in the NHS (P = 0.03 and P = 0.003, respectively) though not in the WHS. Pooled analysis of the NHS and WHS cohorts demonstrated significant association of sTNFRII with RA (relative risk 2.0 [95% confidence interval 1.1-3.6], P for trend = 0.004), and a modest association of IL-6 with RA (relative risk 1.4 [95% confidence interval 0.8-2.5], P for trend = 0.06). CONCLUSION: Levels of sTNFRII, a biomarker typically associated with active RA, were elevated up to 12 years prior to the development of RA symptoms and were positively associated with incident RA in these nested case-control studies. Studies with repeated assessments of biomarkers prior to RA development may provide further insight into the timing of biomarker elevation in preclinical RA.

Chibnik LB, Mandl LA, Costenbader KH, Schur PH, Karlson EW. · Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02115, USA. · J Rheumatol. · Pubmed #19228654 No free full text.

Abstract: OBJECTIVE: Anti-cyclic citrullinated peptide (anti-CCP) antibodies are strongly associated with increased risk of rheumatoid arthritis (RA).While the anti-CCP level is commonly dichotomized for clinical use, the best threshold for and utility of the titer as a continuous variable to predict development of RA are uncertain. METHODS: Using data from the Nurses' Health Study and Nurses' Health Study II longitudinal cohorts, we examined the sensitivity, specificity, and hazard of RA at various thresholds of the anti-CCP. Incident RA was confirmed using the Connective Tissue Disease Screening Questionnaire and medical record review in 93 women from among 62,437 participants with blood samples. Three controls per case were randomly chosen, matching on cohort, age, and menopausal status. Stored plasma was tested for anti-CCP antibodies with the second-generation Diastat ELISA. Five threshold values were assessed for sensitivity, specificity, and time to diagnosis of RA. Hazard of RA was assessed with conditional logistic regression models adjusting for smoking and reproductive factors. RESULTS: Using the suggested threshold of >5 U/ml for anti-CCP positivity, specificity was 100%, but sensitivity was only 28%. A threshold of >2 U/ml had a higher sensitivity (51%), and similar specificity (80%), with an odds ratio of 11.2 (95% confidence interval 4.7-26.9) for RA. Anti-CCP level as an ordinal variable was strongly associated with time to RA onset, with higher values predicting shorter time to RA onset. CONCLUSION: A lower threshold for anti-CCP positivity was more sensitive in predicting RA development. Higher ranges of the level were informative in predicting time to RA onset.

Lee DM, Phillips R, Hagan EM, Chibnik LB, Costenbader KH, Schur PH. · Department of Medicine, Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Smith 552B, 1 Jimmy Fund Way, Boston, Massachusetts 02115, USA. · Ann Rheum Dis. · Pubmed #18390910 No free full text.

Abstract: OBJECTIVE: To determine the significance of quantitative levels of antibodies to cyclic citrullinated peptides (anti-CCP) in a population of patients with rheumatoid arthritis (RA). METHODS: A total of 241 consecutive sera from patients with RA sent from a large rheumatology clinic for laboratory testing were selected for precisely quantifying anti-CCP antibody titres with the anti-CCP2 assay. Patient charts were reviewed for demographic information, smoking history, clinical diagnosis, rheumatoid factor (RF) titre, radiographic information and other laboratory information (erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level). Correlations with anti-CCP titre and RF titre, disease parameters and smoking history were assessed. RESULTS: We confirm previous findings that anti-CCP seropositivity is associated with a higher incidence of erosions in patients with RA (56% vs 20% CCP+ vs CCP-, kappa = 0.297, p<0.001). We also found a moderate correlation between anti-CCP titre and RF titre. However, we failed to find an association between anti-CCP titre and presence of erosions, between anti-CCP titre and CRP or ESR level, or between anti-CCP titre and age or disease duration. Interestingly, we did find significantly higher anti-CCP titres in patients with a history of smoking (452 units/ml vs 229 units/ml, smokers vs non-smokers, respectively; p = 0.02). CONCLUSIONS: Although anti-CCP titres were not associated with clinical parameters of disease, they are increased in patients with RA with exposure to tobacco. By contrast, no elevation in RF was noted in patients with a history of smoking. These observations are consistent with a pathogenic contribution of smoking to RA and suggest the immune stimulus for anti-CCP is distinct from that for RF.

Karlson EW, Chibnik LB, Cui J, Plenge RM, Glass RJ, Maher NE, Parker A, Roubenoff R, Izmailova E, Coblyn JS, Weinblatt ME, Shadick NA. · Division of Rheumatology, Allergy, and Immunology, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA. · Ann Rheum Dis. · Pubmed #17666451 links to  free full text

Abstract: BACKGROUND: HLA-DRB1 shared epitope (HLA-SE), PTPN22 and CTLA4 alleles are associated with cyclic citrullinated peptide (CCP) and rheumatoid arthritis (RA). OBJECTIVE: We examined associations between HLA-SE, PTPN22, CTLA4 genotypes and RA phenotypes in a large cohort to (a) replicate prior associations with CCP status, and (b) determine associations with radiographic erosions and age of diagnosis. METHODS: A total of 689 RA patients from the Brigham RA Sequential Study (BRASS) were genotyped for HLA-SE, PTPN22 (rs2476601) and CTLA4 (rs3087243). Association between genotypes and CCP, rheumatoid factor (RF) erosive phenotypes and age at diagnosis were assessed with multivariable models adjusting for age, sex and disease duration. Novel causal pathway analysis was used to test the hypothesis that genetic risk factors and CCP are in the causal pathway for predicting erosions. RESULTS: In multivariable analysis, presence of any HLA-SE was strongly associated with CCP+ (odds ratio (OR) 3.05, 95% CI 2.18-4.25), and RF+ (OR 2.53, 95% CI 1.83-3.5) phenotypes; presence of any PTPN22 T allele was associated with CCP+ (OR 1.81, 95% CI 1.24-2.66) and RF+ phenotypes (OR 1.84, 95% CI 1.27-2.66). CTLA4 was not associated with CCP or RF phenotypes. While HLA-SE was associated with erosive RA phenotype (OR 1.52, 95% CI 1.01-2.17), this was no longer significant after conditioning on CCP. PTPN22 and CTLA4 were not associated with erosive phenotype. Presence of any HLA-SE was associated with an average 3.6 years earlier diagnosis compared with absence of HLA-SE (41.3 vs 44.9 years, p = 0.002) and PTPN22 was associated with a 4.2 years earlier age of diagnosis (39.5 vs 43.6 years, p = 0.002). CTLA4 genotypes were not associated with age at diagnosis of RA. CONCLUSIONS: In this large clinical cohort, we replicated the association between HLA-SE and PTPN22, but not CTLA4 with CCP+ and RF+ phenotypes. We also found evidence for associations between HLA-SE, and PTPN22 and earlier age at diagnosis. Since HLA-SE is associated with erosive phenotype in unconditional analysis, but is not significant after conditioning on CCP, this suggests that CCP is in the causal pathway for predicting erosive phenotype.

Agarwal SK, Maier AL, Chibnik LB, Coblyn JS, Fossel A, Lee R, Fanikos J, Fiumara K, Lowry C, Weinblatt ME. · Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA. · Arthritis Rheum. · Pubmed #16342095 links to  free full text

Abstract: OBJECTIVE: To investigate the pattern of use of infliximab with an emphasis on treatment escalation and the durability of infliximab use in the management of rheumatoid arthritis (RA) in an academic setting. METHODS: We conducted a retrospective review of pharmacy and medical records of 183 patients with RA who received at least 1 infliximab infusion at the infusion centers of the Brigham and Women's Hospital. Treatment escalation was defined as an increase in the dosage of infliximab to >3 mg/kg and/or a decrease in the dosing interval to <7 weeks between infusions. RESULTS: A total of 183 patients with RA received infliximab infusions for a mean +/- SD duration of 58.2 +/- 56.6 weeks. Infliximab was discontinued in 48% of the patients during the first year of therapy and in 67% of the patients overall. A total of 126 patients had a treatment escalation, including 25 patients with a dose increase, 35 patients with a decrease in the interval, and 66 patients with both. Infliximab treatment was associated with a decrease in corticosteroid and methotrexate doses. Patients who had a treatment escalation were more likely to continue infliximab infusions compared with patients without a treatment escalation (odds ratio 2.0, 95% confidence interval 1.0-4.1). CONCLUSION: The use of infliximab may be an effective treatment for RA; however, a substantial number of patients will discontinue its use. Treatment escalation is commonly used in the management of RA with infliximab and is associated with longer duration of infliximab use.