Hypertension: an autoimmune disease?

Cardiovascular risk in rheumatoid arthritis: assessment, management and next steps

Rheumatoid arthritis (RA) is associated with increased cardiovascular (CV) morbidity and mortality which cannot be fully explained by traditional CV risk factors; cumulative inflammatory burden and antirheumatic medication-related cardiotoxicity seem to be important contributors. Despite the acknowledgment and appreciation of CV disease burden in RA, optimal management of individuals with RA represents a challenging task which remains suboptimal. To address this need, the European League Against Rheumatism (EULAR) published recommendations suggesting the adaptation of traditional risk scores by using a multiplication factor of 1.5 if two of three specific criteria are fulfilled. Such guidance requires proper coordination of several medical specialties, including general practitioners, rheumatologists, cardiologists, exercise physiologists and psychologists to achieve a desirable result. Tight control of disease activity, management of traditional risk factors and lifestyle modification represent, amongst others, the most important steps in improving CV disease outcomes in RA patients. Rather than enumerating studies and guidelines, this review attempts to critically appraise current literature, highlighting future perspectives of CV risk management in RA.

Prevention of cardiovascular disease in rheumatoid arthritis

The increased risk of cardiovascular disease (CVD) in rheumatoid arthritis (RA) has been recognized for many years. However, although the characteristics of CVD and its burden resemble those in diabetes, the focus on cardiovascular (CV) prevention in RA has lagged behind, both in the clinical and research settings. Similar to diabetes, the clinical picture of CVD in RA may be atypical, even asymptomatic. Therefore, a proactive screening for subclinical CVD in RA is warranted. Because of the lack of clinical trials, the ideal CVD prevention (CVP) in RA has not yet been defined. In this article, we focus on challenges and controversies in the CVP in RA (such as thresholds for statin therapy), and propose recommendations based on the current evidence. Due to the significant contribution of non-traditional, RA-related CV risk factors, the CV risk calculators developed for the general population underestimate the true risk in RA. Thus, there is an enormous need to develop adequate CV risk stratification tools and to identify the optimal CVP strategies in RA. While awaiting results from randomized controlled trials in RA, clinicians are largely dependent on the use of common sense, and extrapolation of data from studies on other patient populations. The CVP in RA should be based on an individualized evaluation of a broad spectrum of risk factors, and include: 1) reduction of inflammation, preferably with drugs decreasing CV risk, 2) management of factors associated with increased CV risk (e.g., smoking, hypertension, hyperglycemia, dyslipidemia, kidney disease, depression, periodontitis, hypothyroidism, vitamin D deficiency and sleep apnea), and promotion of healthy life style (smoking cessation, healthy diet, adjusted physical activity, stress management, weight control), 3) aspirin and influenza and pneumococcus vaccines according to current guidelines, and 4) limiting use of drugs that increase CV risk. Rheumatologists should take responsibility for the education of health care providers and RA patients regarding CVP in RA. It is immensely important to incorporate CV outcomes in testing of anti-rheumatic drugs.

Irreversible renal damage after transient renin-angiotensin system stimulation: involvement of an AT1-receptor mediated immune response

Transient activation of the renin-angiotensin system (RAS) induces irreversible renal damage causing sustained elevation in blood pressure (BP) in Cyp1a1-Ren2 transgenic rats. In our current study we hypothesized that activation of the AT₁-receptor (AT₁R) leads to a T-cell response causing irreversible impairment of renal function and hypertension. Cyp1a1-Ren2 rats harbor a construct for activation of the RAS by indole-3-carbinol (I3C). Rats were fed a I3C diet between 4–8 weeks of age to induce hypertension. Next, I3C was withdrawn and rats were followed-up for another 12 weeks. Additional groups received losartan (20 mg/kg/day) or hydralazine (100 mg/kg/day) treatment between 4–8 weeks. Rats were placed for 24h in metabolic cages before determining BP at week 8, 12 and 20. At these ages, subsets of animals were sacrificed and the presence of kidney T-cell subpopulations was investigated by immunohistochemistry and molecular marker analysis. The development of sustained hypertension was completely prevented by losartan, whereas hydralazine only caused a partial decrease in BP. Markers of renal damage: KIM-1 and osteopontin were highly expressed in urine and kidney samples of I3C-treated rats, even until 20 weeks of age. Additionally, renal expression of regulatory-T cells (Tregs) was highly increased in I3C-treated rats, whereas the expression of T-helper 1 (Th1) cells demonstrated a strong decrease. Losartan prevented these effects completely, whereas hydralazine was unable to affect these changes. In young Cyp1a1-Ren2 rats AT₁R activation leads to induction of an immune response, causing a shift from Th1-cells to Tregs, contributing to the development of irreversible renal damage and hypertension.

Angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers and the risk of developing rheumatoid arthritis in antihypertensive drug users

PURPOSE

Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) are effective in the treatment of cardiovascular disease. Next to effects on hypertension and cardiac function, these drugs have anti-inflammatory and immunomodulating properties which may either facilitate or protect against the development of autoimmunity, potentially resulting in autoimmune diseases. Therefore, we determined in the current study the association between ACE inhibitor and ARB use and incident rheumatoid arthritis (RA).

METHODS

A matched case-control study was conducted among patients treated with antihypertensive drugs using the Netherlands Information Network of General Practice (LINH) database in 2001-2006. Cases were patients with a first-time diagnosis of RA. Each case was matched to five controls for age, sex, and index date, which was selected 1 year before the first diagnosis of RA. ACE inhibitor and ARB exposure was considered to be any prescription issued in the period before index date. Logistic regression analysis was used to estimate odds ratios (ORs) and their 95% confidence intervals (CI).

RESULTS

Our study included 211 cases and 667 matched controls. After controlling for potential confounders, ever use of ACE inhibitors or ARBs was not associated with incident RA (adjusted ORs [95%CI], 0.99 [0.55-1.79] and 1.02 [0.67-1.56], respectively). The adjusted ORs (95%CI) for current and past use of ACE inhibitors were 1.18 (0.75-1.85) and 0.61 (0.28-1.35). For current and past use of ARBs, these adjusted ORs (95%CI) were 1.40 (0.80-2.45) and 0.29 (0.05-1.67), respectively. No duration and dose-effect relationship was observed.

CONCLUSIONS

ACE inhibitor or ARB use is not associated with incident RA.

Angiogenic T-cells and putative endothelial progenitor cells in hypertension-related cerebral small vessel disease

BACKGROUND AND PURPOSE

Cerebral small vessel disease (CSVD) may be caused by endothelial dysfunction, whereas endothelial progenitor cells (EPC) may attenuate endothelial dysfunction. Their vitality is lower in CSVD. A subset of lymphocytes, angiogenic T-cells, is capable to stimulate EPC function. The purpose of our study was to explore the relation between CSVD manifestations, angiogenic T-cells, and EPC in hypertensive patients with CSVD.

METHODS

We compared 32 essential hypertensive patients with CSVD (white matter lesions, asymptomatic lacunar infarcts, or microbleeds on 1.5-Tesla MRI) to 29 age-matched and sex-matched hypertensive controls. We counted angiogenic T-cells (CD3(+)/CD31(+)/CD184(+)) and putative EPC (CD31(+)/CD34(+)/CD45(-)/KDR(+)) by flow cytometry and determined EPC vitality by in vitro cluster formation.

RESULTS

Putative EPC numbers were lower in hypertensive individuals with CSVD than in those without (10±7(.)10(3)/mL versus 13±6(.)10(3)/mL [median±interquartile range]; P=0.011). Angiogenic T-cell numbers were also lower in hypertensive individuals with CSVD than in those without (0.56±0.25(.)10(9)/mL versus 0.78±0.50(.)10(9)/mL; P=0.008). Higher angiogenic T-cell numbers independently related to absence of CSVD (odds ratio, 0.088; 95% confidence interval, 0.012-0.627).

CONCLUSIONS

Our data suggest that angiogenic T-cells and putative EPC independently relate to radiological CSVD manifestations in hypertensive patients.