Measurement of Interleukine-6 and C-reactive Protein in Serum of Patients on Amlodipine Therapy

Aims: The aims of this ﬆudy were to compare between the immunological parameters (serum inter-leukin-6 (IL-6) and c-reactive protein (CRP) of patients suﬀering from chronic cardiovascular diseases with amlodipine therapy and control group to determine the eﬀects of the drug on those parameters. Materials and Methods: The ﬆudy was conducted on 42 subjects, 27 patients already on amlodipine therapy, aged ranged between 34-75 years. Fifteen healthy subjects of the same age group par-ticipated in this ﬆudy as a control group. The screening by medical hiﬆory, examination (gingival enlargement scores) and blood samples to measure serum IL-6 and CRP was done once at base line visit. Results: The results obtained showed that amlodipine trherapy group had higher gingival overgrowth scores and immunological parameters than control group with signiﬁcant diﬀerence at (p<0.05), also there was positive correlation but not signiﬁcant between CRP in serum and IL-6 (p< 0.05). Conclusion: The ﬆudy concluded that there is a signiﬁcant diﬀerence in the GO score and immunological parameters in amlodipine therapy group as compared with healthy group.


INTRODUCTION
Amlodipine is a dihydroperidine calcium channel blocker (CCB), used for treatment of hypertension and angina pectoris (stable and prinzmetal's angina (1,2) ). It is given orally in a dose of (2.5-10 mg once daily). It is well absorbed following oral administration, it exhibits very slow kinetics of onset and off set of blockade; with peak blood concentration occurring after 6 to 12 hours. It has a prolonged terminal elimination half life of 30 to 50 hours and extensively metabolized in the liver. (1,2) .
Gingival overgrowth (GO) is one of the side eff ects which had been reported (1,2) .
Drugs associated with GO can be broadly divided into three categories;Anticonvulsants, CCBs, and immunosuppressant (3) .
It is hypothesized that non infl amed gingival fi broblasts are less active or even quiescent and do not respond to circulating drugs. While the fi broblasts within infl amed tissue are in an active state, as a result of infl ammatory mediators and endogenous growth factors (4) .
Gauldie et al., (5) founded that IL-6 is a potent inducer of the acute-phase reactant including CRP, a response of the organism to several pathological conditions, which is believed to constitute a rapid and general defense mechanism against injury prior to the onset of the immune response. C-Reactive protein is an abnormal specifi c glycoprotein which is primairly derived via IL-6 dependent hepatic biosynthesis (6) and is secreted in increased amounts within six hours of an acute infl ammatory stimulus (7) .
The aims of this study were to compare between the immunological parameters of patients with amlodipine therapy and control group to determine the eff ects of the drug on those parameters.

MATERIALS and METHODS
This study was conducted at outpatient clinic in Ibn Sina Teaching Hospital in Mosul City. The study includes patients already on amlodipine therapy (more than 12 weeks of therapy). This group consisted of 27 patients accepted to participate in this study, their age ranged between (34-75) years and mean age was (53.33±10.674) years. All patients had professional diagnosis for which they had prescribed the drug.
Any patients taking anticonvulsants, immunosuppressants, or any other medications known to produce gingival enlargement were excluded from the study. Female patients enrolled in this study were not pregnant, lactating nor taking oral contraceptive pills.
The screening by medical history, gingival enlargement examined by vision if there is enlargement involve interdental papilla, marginal gingival or enlargement covers three quarters or more of the crown (8) and blood samples was done once at base line visit.
The determination of IL-6 in human serum was done using Enzyme immunoassay Kit (IMMUNOTECH, France) and for C-reactive protein was done using high sensitivity CRP enzyme immunoassay kit (Biocheck, USA).
Statistical analysis of data were conducted using SPSS 17 for windows software. A p-value of ≤ 0.05 was considered statistically signifi cant, the The t test was used for the analysis of data (12) . Pearson correlations were used to evaluate correlations between parametric variables.

RESULTS
Table (1) demonstrates that the mean values of IL-6, CRP in the amlodipine therapy group were signifi cantly higher than control group. Table (2) shows that serum CRP was positively but not signifi cantly correlated with serum IL-6 .

DISCUSSION
There are higher GO in mlodipine therapy group than control group (Table (1)). Osterberg (9) reported that CCB causes signifi cantly higher GO scores Gingival enlargement can be observed after a few weeks or after a few years from the beginning of the treatment, being reversible after interruption of the drug that is generating it, a fact that underlines the necessity of periodic, specialized examinations, because the real defi nition of GO is represented by the increase, with more than 1 mm of the inter-dental papilla (10,11) .
Infl ammation of the gingival tissue from the bacterial plaque and the subsequent development of gingival crevicular fl uid may allow sequestration of the amlodipine, Measurement of Interleukine6-and C-reactive Protein in Serum of Patients on Amlodipine Therapy thus predisposing the tissue to a localized, toxic eff ect and to the development of GO (11) . Apoptosis is a process that acts in concert with mitosis to preserve cellular homeostasis or to facilitate tissue remodeling during development. It involves a cascade of biochemical steps, which require a rise in the level of intracellular calcium. Amlodipine was well known as a CCB and inhibits the calcium infl ux from extracellular fl uid.
Blockade of one or more steps in the cascade by amlodipine results in a decrease in apoptosis rate. This inhibition of apoptosis in the epithelium leads to cell accumulation, resulting in GO (12) . When we are dealing with important tissue destruction and the presence of a periodontal pouch, there is a clear association with many markers of infl ammation: high sensitivity CRP, homocysteine, fi brinogen, proinfl ammatory cytokines plasmatic concentration (13) . This infl ammatory process represents the result of the interaction between pathological agents and the reactivity of the host (14) .
The highest prevalence of pereiodontal disease (PD) and cardiovascular disease (CVD) is encountered in middle and old age people. During the last years, CCB reached the fi rst line of treatment, a level of evidence recommendation in treating coronary heart disease, the most fearful and most frequent expression of atherosclerosis (15) . So, the problem became more complicated: fi rst to demonstrate a causal link between periodontal disease (PD) and cardiovascular disease (CVD) and, then, to fi nd if CCB, although they have a benefi al eff ect in coronary heart disease, could have a deleterious eff ect on the periodontium (14,16) .
There is higher serum IL-6 in amlodipine therapy group than control group. These elevated infl ammatory factors may increase infl ammatory activity in atherosclerotic lesions and potentially increasing the risk for cardiovascular events (17) . There is higher serum CRP level in amlodipine therapy group than control group (Table 1) with signifi cant diff erence. Hirasaki et al., (18) found that blood CRP level increased in patients with CVD, and that CVD is accompanied by oral infection such as periodontal disease compared to that in healthy patients. Megson et al. (19) . reported CRP in the gingival crevicular fl uid (GCF) appears to be of systemic origin, and therefore may be indicative of systemic infl ammation from either a periodontal infection or infl ammatory disease elsewhere.
In the present study (Table 2), serum CRP is positively correlated with IL-6. Heinisch et al., (20) reported that there is a positive correlation between IL-6 and CRP, but not with the other cytokines in patients with acute coronary syndromes were compared with patients with stable angina and with control volunteers. This study is in contrast to other studies which examined the inter-relationships of the diff erent infl ammatory markers in hypertension. For example, Bautista et al., (21) examined the cross-sectional relationship between IL-6, TNF-a, and hsCRP and hypertension in a random sample of 196 healthy subjects and showed that after adjusting for other risk factors, IL-6 and TNF-a, high sensitivity CRP are not signifi cantly associated with hypertension. Whilst this was a relatively small study and only include 79 hypertensive patients, it is the only study to date to specifi cally analyze the potentially confounding relationship between several infl ammatory markers and hypertension.

CONCLUSIONS
The study concluded there is a signifi cant diff erence in the GO score and immunological parameters in chronic group as compared with healthy group.