Study of the relation between serum levels of long-acting penicillin and the inflammatory markers: C-reactive protein and interleukin-6 in patients with chronic rheumatic heart disease

BACKGROUND: There is an evidence of a chronic inflammatory state in patients with chronic rheumatic valvular heart disease (RHD) as shown by high serum levels of high-sensitivity C-reactive protein (hs-CRP) and interleukin-6 (IL6). Despite the efficacy of long-acting penicillin (LAP) in secondary prevention of rheumatic fever, its effect on this inflammatory state is still unknown. So, we sought to study the effect of LAP on the inflammatory markers, CRP and IL-6, in patients with chronic rheumatic heart disease. RESULTS: Eighty RHD patients coming to our hospital’s outpatient clinic for rheumatic fever secondary prophylaxis by regular administration of LAP were enrolled in the study. Patients were divided into 3 groups: group A, 70 patients with RHD already on prophylactic LAP, group B, 10 patients with RHD who have not yet started prophylactic LAP, and group C, control group of 10 healthy individuals not known to have RHD. Serum levels of LAP, IL-6, and CRP were measured for the three groups. Group A had significantly lower IL-6 levels than group B (25.22 ± 33.50 vs. 126.1 ± 33.76nng/ml, respectively, p < 0.0001). IL-6 levels were significantly lower in control subjects compared to patients in group B (3.600 ± 2.319, 25.22 ± 33.50 ng/ml, respectively, p < 0.0001). However, IL-6 levels in the control group were lower but non-significantly different compared to group A. CRP level was lower in group A than group B (8419 ± 4935 vs. 14400 ± 3375 mg/dl, respectively, p = 0.0002). CRP levels were significantly lower in control subjects compared to patients in group A and group B. IL-6 values were positively correlated with CRP values (r = 0.6387, p < 0.0001). CRP values were negatively correlated with LAP values (r = -0.5277, p < 0.0001). IL-6 values were negatively correlated with LAP values (r = − 0.4401, p < 0.0001). There was a highly significant difference between LAP level in compliant and non-compliant patients (1.045 ± 1.270 vs. 0.0785 ± 0.1057 ng/ml, respectively, p value < 0.0001). There was also a highly significant difference between CRP level in compliant and non-compliant patients (7640 ± 4558 vs. 13090 ± 4717 mg/dl, respectively, p = 0.005). Moreover, there was a significant difference between IL-6 levels in compliant and non-compliant patients (21.53 ± 32.70 vs. 47.40 ± 30.91 ng/ml, respectively, p value 0.03). CONCLUSION: Serum LAP has a strong negative correlation with IL-6 and CRP levels. Regular administration of LAP strongly ameliorates the inflammatory state seen in patients with RHD.