Background/Purpose: We recently discovered correlations between a profile of cytokines produced in response to human cytomegalovirus (CMV), poor treatment outcome, and erosive joint damage. The objective of this study was to determine if a similar CMV-induced cytokine profile would also correlate with myocardial disease in patients with RA.

Methods: A correlative study of 324 patients with RA in our population-based inception cohort was performed. Diastolic function was evaluated using transthoracic 2D/Doppler echocardiography and categorized as normal, mild LVDD, moderate-to-severe LVDD or heart failure, or indeterminate. Immunological profiles of 17 cytokines (IFN-γ, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IL-17A, MCP-1, MIP-1β, G-CSF, GM-CSF, TNF-α) produced by peripheral blood mononuclear cells (PBMCs) in response to stimulation with combined cytomegalovirus or Epstein-Barr virus lysates (CMV/EBV) were assessed using multiplex assays. Principal components analysis (PCA) was used to derive robust and informative cytokine profiles based on the 1^st, 2^nd and 3^rd principal components. Mixed effects models were used to normalize the data and test for associations between the CMV/EBV PCA scores and moderate-to-severe LVDD/HF, adjusting for age, sex, cardiovascular risk factors, and RA disease characteristics. Among a separate sample of 64 patients with early RA having available viral serologies, the PCA scores were correlated with CMV or EBV IgG.

Results: The mean age of the subjects was 60.4 years, 74% were female, and the mean RA duration was 9.9 years. 151 (47%) had normal diastolic function, 64 (20%) had mild LVDD, 35 (11%) had moderate-to-severe LVDD or HF, and 74 (23%) were indeterminate. The PCA scores for the 2nd and 3rd principal components (PCA-2 and PCA-3, respectively) were associated with moderate-to-severe LVDD or HF compared to patients with normal diastolic function (odds ratio = 1.28 per 10-unit increase in the 100 point score, p = 0.022 and odds ratio = 1.24, p = 0.067, respectively). The five most informative cytokines in PCA-2 (from highest to lowest importance) were G-CSF, IL-6, IL-8, IL-1β, and GM-CSF and in PCA-3 were TNF-α, MIP-1β, IL-8, IL-1β, and IFN-γ. Among patients with early RA, both PCA-2 (r = 0.25, p = 0.06) and PCA-3 (r = 0.38, p = 0.003) were shown to correlate with CMV IgG whereas neither of the PCA scores were found to correlate with EBV IgG (r < 0.1 for all). A signature incorporating PCA-2 was developed with very good accuracy in predicting advanced myocardial disease (C-statistic = 0.834).

Conclusion: A profile of CMV-related immunity is associated with moderate-to-severe LVDD in persons with RA. The findings are relevant to developing myocardial risk assessment tools and to understanding how perturbations in innate and adaptive immunity in relation to latent CMV infection impact the pathophysiology of myocardial disease in RA.