Chlamydial infection and progression of carotid atherosclerosis in patients on regular haemodialysis

Malnutrition, inflamation and atherosclerosis (MIA syndrome) in patients with end stage renal disease on maintenance hemodialysis (a single centre experience)

BACKGROUND

Inflammation and malnutrition play an important role in endothelial dysfunction, atherosclerosis and excessive cardiovascular morbidity and mortality in ESRD patients AIM OF THE STUDY: The primary objective is to determine the prevalence of inflammation, malnutrition and atherosclerosis in patients on maintenance haemodialysis. Secondary objective was to determine the association for atherosclerosis with inflammation and malnutrition.

PATIENT AND METHODS

One hundred and one adult patients with end stage renal disease on maintenance haemodialysis who are met with the exclusion criteria were enrolled in this cross sectional study from haemodialysis unit of Baghdad teaching hospital over the period of July/2015 - June 2016. All patients were thoroughly examined and many variables were evaluated (age, gender, blood pressure, diabetes mellitus, serum lipid profile, smoking habits, serum albumin, CRP, calcium, Phosphate, Parathyroid hormone and haemoglobin measurements). All patients underwent a carotid Doppler ultrasound study.

RESULTS

Atherosclerosis was present in 65.3%: 58.4% of patients had malnutrition and 43.6% had inflammation. The association for atherosclerosis and high CRP and low serum albumin is strong and independent of other atherosclerosis risk factors. There is significant inverse and independent correlation between CRP and albumin.

CONCLUSION

Inflammation (high serum CRP) and malnutrition (low serum albumin) in patients on haemodialysis are significantly associated with carotid atherosclerosis. Inflammation was more prevalent in the malnourished patients than in those with normal nutritional status.

A single center, open-label, randomized, parallel group study assessing the relationship between asymptomatic bacteriuria and inflammation in maintenance hemodialysis patients

INTRODUCTION

The significance of asymptomatic bacteriuria in maintenance hemodialysis (MHD) patients remains controversial. We hypothesized that the presence of asymptomatic bacteriuria as a sole clinical manifestation of urinary tract infection (UTI) in asymptomatic MHD patient may contribute to the chronic inflammatory response. Our aim was to explore the relationship between asymptomatic bacteriuria and elevated levels of inflammatory markers in MHD patients.

METHODS

A randomized open-label single center study of 114 MHD patients was conducted. Forty-six patients presented negative urine culture and 41 subjects were excluded due to different reasons. The remaining 27 patients (mean age of 71.5 ± 12.2 years, 63% men), fulfilling the criteria for having asymptomatic bacteriuria, were randomly assigned to either the treatment group (13 patients) or the observational group (14 subjects). The treatment group received 7 days of antibiotic treatment given according to bacteriogram sensitivity. After 3 months of follow-up all measurements of the study were repeated. The primary end point was change in inflammatory biomarkers from baseline by the end of the study.

FINDINGS

There were no statistically significant differences in white blood cell changes (P = 0.27), ferritin (P = 0.09), C-reactive protein (P = 0.90), and interleukin-6 (P = 0.14) levels between the groups from baseline to the end of study or at the end of the study. Analyzing cross-sectional data, asymptomatic bacteriuria was found to not be a predictor of higher levels of inflammatory parameters at baseline.

DISCUSSION

Asymptomatic bacteriuria is not a modifiable risk factor for chronic inflammation in the MHD population.

Relative risk for cardiovascular morbidity in hemodialysis patients regarding gene polymorphism for IL-10, IL-6, and TNF

Uremia-related inflammation is prone to be a key factor to explain high cardiovascular morbidity in hemodialysis patients. Genetic susceptibility may be of importance, including IL-10, IL-6, and TNF. The aim was to analyze IL-10, IL-6, and TNF gene polymorphisms in a group of hemodialysis patients and to correlate the findings with cardiovascular morbidity. This study included 169 patients on regular hemodialysis at Zvezdara University Medical Center. Gene polymorphisms for IL-10, IL-6 and TNF were determined using PCR. These findings were correlated with the cardiovascular morbidity data from patient histories. Heterozygots for IL-10 gene showed significantly lower incidence of cardiovascular events (p = 0.05) and twice lower risk for development of myocardial infarction, but experienced twice higher risk for left ventricular hypertrophy. Regarding TNF gene polymorphism, patients with A allele had 1.5-fold higher risk for cerebrovascular accident and cardiovascular events and 2-fold higher risk for hypertension and peripheral vascular disease. Patients with G allele of IL-6 gene experienced 1.5-fold higher risks for cerebrovascular accident. We need studies with larger number of patients for definitive conclusion about the influence of gene polymorphisms on cardiovascular morbidity in hemodialysis patients and its importance in everyday clinical practice.

A prospective study: inflammation, infection and comorbidity in patients on long-term dialysis

BACKGROUND

The goal of this study was to identify inflammatory and infectious markers and their roles in mortality.

METHODS

We enrolled 111 patients on haemodialysis (HD) and collected data at three time points (baseline, 33 and 76 months).

RESULTS

Rates of Chlamydophila pneumoniae IgG, CRP ≥3 mg/l, ESR >50 mm/hour and fibrinogen >4 g/l were, respectively, 63.1%, 60.4%, 48.6% and 42.3%. Mortality was 21.6% and 43.2% at 33 and 76 months where 58.3% of all deaths were cardiocerebrovascular (CCV) related. Non-survivors were older than survivors. Univariate analysis showed diabetes mellitus (DM) and cerebrovascular accident (CVA) as important for the 33-month all-cause mortality, and CRPlog , fibrinogen, ESR >50 mm/hour, cardiovascular disease (CVD) and DM for the 76-month all-cause mortality. CVA was meaningful for the 33-month CCV mortality, and CVD, DM and ESR >50 mm/hour for the 76-month CCV mortality. Kaplan-Meier revealed poorer survival for patients with ESR >50 mm/hour at 76 months. Cox regression showed CVD, CVA and age as mortality predictors.

CONCLUSION

Age, CVD and CVA are predictors for mortality in patients on HD patients, but the presence of C. pneumoniae IgG and inflammation are not.

A comparison of systemic inflammation-based prognostic scores in patients on regular hemodialysis

Background/Aims

Systemic inflammation-based prognostic scores have prognostic power in patients with cancer, independently of tumor stage and site. Although inflammatory status is associated with mortality in hemodialysis (HD) patients, it remains to be determined as to whether these composite scores are useful in predicting clinical outcomes.

Methods

We calculated the 6 prognostic scores [Glasgow prognostic score (GPS), modified GPS (mGPS), neutrophil-lymphocyte ratio (NLR), platelet lymphocyte ratio (PLR), prognostic index (PI) and prognostic nutritional index (PNI), which have been established as a useful scoring system in cancer patients. We enrolled 339 patients on regular HD (age: 64 ± 13 years; time on HD: 129 ± 114 months; males/females = 253/85) and followed them for 42 months. The area under the receiver-operating characteristics curve was used to determine which scoring system was more predictive of mortality.

Results

Elevated GPS, mGPS, NLR, PLR, PI and PNI were all associated with total mortality, independent of covariates. If GPS was raised, mGPS, NLR, PLR and PI were also predictive of all-cause mortality and/or hospitalization. GPS and PNI were associated with poor nutritional status. Using overall mortality as an endpoint, the area under the curve (AUC) was significant for a GPS of 0.701 (95% CI: 0.637-0.765; p < 0.01) and for a PNI of 0.616 (95% CI: 0.553-0.768; p = 0.01). However, AUC for hypoalbuminemia (<3.5 g/dl) was comparable to that of GPS (0.695, 95% CI: 0.632-0.759; p < 0.01).

Conclusion

GPS, based on serum albumin and highly sensitive C-reactive protein, has the most prognostic power for mortality prediction among the prognostic scores in HD patients. However, as the determination of serum albumin reflects mortality similarly to GPS, other composite combinations are needed to provide additional clinical utility beyond that of albumin alone in HD patients.

Impact of seropositivity to Chlamydia pneumoniae and anti-hHSP60 on cardiovascular events in hemodialysis patients

Autoimmunity to heat shock protein 60 (HSP60) has been related to atherosclerosis. Chlamydia pneumoniae (CP), the most studied infectious agent implicated in promoting atherosclerosis, produces a form of HSP60, which can induce an autoimmune response, due to high antigenic homology with human HSP60 (hHSP60). In this study, we evaluated the correlations among anti-hHSP60 antibodies, CP infection, and cardiovascular disease (CVD) in a high-risk population, such as patients undergoing hemodialysis (HD). Thirty-two patients (67.9 ± 13.9 years; male/female, 23:9) on regular HD were enrolled. Global absolute cardiovascular risk (GCR) was assessed using the Italian CUORE Project's risk charts, which evaluate age, gender, smoking habits, diabetes, systolic blood pressure, and serum cholesterol. The occurrence of cardiovascular events during a 24-month follow-up was recorded. Seropositivity to CP and the presence of anti-hHSP60 antibodies were tested by specific enzyme-linked immunosorbent assays. Inflammation was assessed by measurement of C-reactive protein (CRP) serum levels. Fifteen healthy sex and age-matched (61.9 ± 9.5 years; male/female, 11:4) subjects were the control group. Fifteen of 32 patients resulted seropositive for CP. CP + patients were older than CP-, while they did not differ for GCR, CRP, and dialytic parameters. CVD incidence was significantly higher in CP+ (9 CP+ vs 2 CP-, p < 0.05). Cox analysis recognized that the incidence of CVD was independently correlated with seropositivity to CP (HR, 7.59; p = 0.01; 95% CI = 1.63-35.4). On the other hand, there were no significant differences in anti-hHSP60 levels among CP+, CP- and healthy subjects: 18.11 μg/mL (14.8-47.8), 31.4 μg/mL (23.2-75.3), and 24.72 μg/mL (17.7-41.1), respectively. Anti-hHSP60 did not correlate to GCR, CRP, and incidence of CVD. In conclusion, our data suggest that anti-hHSP60 autoimmune response is not related to CP infection and CP-related CVD risk in HD patients.

Comparison of serum albumin, C-reactive protein and carotid atherosclerosis as predictors of 10-year mortality in hemodialysis patients

Serum albumin, C-reactive protein (CRP), and the intima-medial thickness of the common carotid artery (CA-IMT) are associated with clinical outcomes in hemodialysis (HD) patients. However, it remains unclear which parameters are more reliable as predictors of long-term mortality. We measured serum albumin, CRP, and CA-IMT in 206 HD patients younger than 80 years old, and followed them for the next 10 years. One hundred sixty-eight patients (age: 57 +/- 11 years, time on HD: 11 +/- 7 years) were enrolled in the analyses. We divided all patients into three tertiles according to their albumin levels, and conducted multivariate analyses to examine the impact on 10-year mortality. Seventy-three (43.5%) patients had expired during the follow-up. Serum albumin was significantly lower in the expired patients than in the surviving patients (3.8 +/- 0.3 vs. 4.0 +/- 0.3, P<0.01), while CRP (4.7 +/- 5.0 vs. 2.8 +/- 3.5 g/L, P=0.01) and CA-IMT (0.70 +/- 0.15 vs. 0.59 +/- 0.11 mm, P<0.01) were significantly higher in the expired group. The multivariate analysis revealed that there was a significantly higher risk for total mortality in HD patients with serum albumin <3.8 g/dL (odds ratio 5.04 [95% CI: 1.30-19.60], P=0.02) when compared with those with albumin >4.1 g/dL. In contrast, CRP and CA-IMT did not associate with total death. It follows from these findings that serum albumin is more superior as a mortality predictor compared with CRP and CA-IMT in HD patients.

Inflammatory syndrome in patients on hemodialysis

Mortality is markedly elevated in hemodialysis (HD) patients. Between 30 and 50% of prevalent patients have elevated serum levels of inflammatory markers such as C-reactive protein and IL-6. The presence of inflammation, chronic or episodic, has been found to be associated with increased mortality risk. The causes of inflammation are multifactorial and include patient-related factors, such as underlying disease, comorbidity, oxidative stress, infections, obesity, and genetic or immunologic factors, or on the other side, HD-related factors, mainly depending on the membrane biocompatibility and dialysate quality. The adequate knowledge of these causes and their prevention or treatment if possible may contribute to improving the inflammatory state of patients who are on HD and possibly their mortality.

Increased levels of C-reactive protein in hypothyroid patients and its correlation with arterial stiffness in the common carotid artery

OBJECTIVE

Hypothyroidism is associated with increased morbidity from cardiovascular disease. The arterial stiffness index beta (stiffness beta) in the common carotid artery (CCA), which is a parameter of arterial stiffening, is known to increase in hypothyroid patients, while normalization of thyroid function for 1 year by levothyroxine (L-T(4)) replacement therapy significantly decreases CCA stiffness beta. Since serum C-reactive protein (CRP) has recently emerged as an independent factor for cardiovascular risk, the present study was designed to examine whether hypothyroidism causes an increase in CRP and whether the serum CRP level is correlated with CCA stiffness beta in hypothyroid patients.

PATIENTS AND METHODS

Serum CRP levels and CCA stiffness beta were determined in 46 patients with hypothyroidism and in 46 age- and sex-matched normal control subjects. Thirty-five patients were further monitored for change in CCA stiffness beta during 1 year in the euthyroid state induced by L-T(4) therapy.

RESULTS

Baseline CRP and CCA stiffness beta were both significantly higher in hypothyroid patients than in normal controls [1064.6+/-224.3 vs. 602.1+/-43.3 ng/ml (mean+/-SE), p<0.0001; and 9.25+/-0.84 vs. 8.21+/-0.85, p<0.05, respectively]. Baseline CRP was significantly correlated in a positive manner with baseline values of CCA stiffness beta (r=0.683, p<0.0001). In multivariate analysis, baseline CCA stiffness beta was significantly associated with baseline levels of serum CRP (r=0.740, p<0.0001). During 1 year of L-T(4) replacement therapy, significant decrease in stiffness beta (from 9.25+/-0.84 to 8.57+/-0.58, p<0.0001) to the normal levels was found. Moreover, the change in CCA stiffness beta during L-T(4) replacement therapy was significantly and independently associated in a negative fashion with baseline levels of serum CRP (r=-0.696, p=0.0002).

CONCLUSIONS

This study suggests that increased serum CRP might have an important independent role in increased arterial stiffening and the measurement of serum CRP is a useful predictor for the degree of improvement of arterial stiffening in hypothyroid patients.

Association between seroprevalence of anti-chlamydial antibodies and long-term cardiovascular mortality in chronic hemodialysis patients

Chlamydial infection has been suspected in the pathogenesis of ischemic heart disease. However, it remains undetermined if persistent chlamydial infection is related to cardiovascular mortality in regular hemodialysis (HD) patients. We measured Chlamydia pneumoniae (Cp) antibody seropositivity in 154 HD subjects (age 59 +/- 11 years, time on HD 13 +/- 7 years, male/female = 101/53), and prospectively examined an association between Cp antibody status and cardiovascular death for 56 months of follow-up. Seropositivity for Cp IgA and IgG antibodies at the entry of the study was 50.6 and 60.8%, respectively. There was no significant difference in age, time on HD, serum albumin, C-reactive protein (CRP) and interleukin-6 (IL-6) between those positive and negative for IgA antibodies. During follow-up over 56 months, 31 patients (20.1%) expired, 16 (55.2%) of them of cardiovascular causes. Serological IgA and IgG antibody positivity did not influence mortality, while multiple Cox proportional hazards analysis revealed that diabetes, ischemic changes on electrocardiogram, log-transformed CRP and intact parathyroid hormone were independent determinants of cardiovascular death. These observations suggest that serological Cp antibody status does not affect long-term cardiovascular mortality in chronic HD patients.

Association of Chlamydia pneumoniae infection and carotid intima-media wall thickness in Japanese Americans

BACKGROUND

Chlamydia pneumoniae (Cp) infection has been proposed as a risk factor for coronary artery disease (CAD), but it remains unclear whether Cp plays a role in the progression of early stage carotid atherosclerosis.

METHODS AND RESULTS

The associations among Cp IgG/IgA antibodies, inflammation markers such as C-reactive protein (CRP) and interleukin (IL)-6, and the maximal progression of carotid intima-media wall thickness (max IMT) were evaluated using ultrasonography in 259 Japanese Americans. The presence of Cp IgG or IgA antibodies itself did not show significant correlation with max IMT after adjustment for age and sex. However, in the Cp IgG seropositive group, the subjects with high IL-6 levels showed more pronounced max IMT progression than those with low IL-6 levels after adjustment of the other CAD risk factors. Moreover, in the Cp IgA seropositive group, the subjects with high CRP or IL-6 levels had significantly higher levels of max IMT compared with those with low CRP or IL-6.

CONCLUSIONS

The results support the hypothesis that a chronic latent Cp infection with inflammation might accelerate the development of early stage atherosclerotic lesions.

Relationship between serum albumin level before initiating haemodialysis and angiographic severity of coronary atherosclerosis in end-stage renal disease patients

BACKGROUND

In patients with chronic kidney disease (CKD), although strong associations have been observed between malnutrition and atherosclerosis, the relationship between serum albumin concentration and angiographic changes of coronary artery disease (CAD) remains poorly explored. The goal of the present study was, in patients with CKD, to clarify the relationship between the angiographic severity of CAD and serum albumin concentration reflecting either inflammation or nutrition or both.

METHODS

In this study, 100 end-stage renal disease (ESRD) patients were enrolled, who commenced long-term dialysis therapy at our hospital and underwent coronary angiography within 3 months of the first haemodialysis (HD) session. Mean age was 63+/-11 years, 20% of the subjects were female and 62% had diabetes. Severity of CAD was evaluated in terms of (i) number of vessels exhibiting CAD (>or=75% stenosis) and (ii) Gensini score (GS). Clinical characteristics and laboratory findings were recorded at initiation of long-term HD therapy. We then evaluated a possible association with the presence and degree of CAD.

RESULTS

Sixty-four patients exhibited signs of CAD. Forty-one among them (64%) had multivessel disease. On univariate logistic regression analysis, age, diabetes and hypoalbuminaemia were significantly associated with multivessel CAD. Univariate linear regression analysis demonstrated a positive correlation of age and diabetes with GS, and an inverse correlation of BMI and serum albumin level with GS. Stepwise regression analysis showed age and serum albumin level to be independently associated with multivessel CAD and GS. The ROC curves demonstrated best cut-off levels of age and albumin for predicting multivessel CAD to be 70 years and 3.15 g/dl, respectively.

CONCLUSION

Hypoalbuminaemia at the initiation of dialysis is an important predictor of advanced CAD, particularly in male and in diabetic patients. It may reflect mainly a state of inflammation. However, malnutrition as a confounding factor cannot be entirely excluded.

IL-10, IL-6, and TNF-alpha: central factors in the altered cytokine network of uremia--the good, the bad, and the ugly

It has been increasingly apparent that wasting and cardiovascular disease (CVD) is associated with a persistent systemic inflammatory response in end-stage renal disease (ESRD) patients. The reasons for the increased risk of inflammation in ESRD patients appear to be complex, including non-dialysis as well as dialysis-related factors. The combination of an impaired immune response coupled with persistent immune stimulation may have a role in the low-grade systemic inflammation and altered cytokine balance that characterizes the uremic state and which may translate into increased risk for vascular disease. The accelerated atherosclerotic process of ESRD may involve several interrelated processes, such as oxidative stress, endothelial dysfunction, and vascular calcification, in a milieu of constant low-grade inflammation with impaired function of neutrophils and T cells, as well as a dysregulated cytokine network. Although a large number of pro- and anti-inflammatory cytokines are of importance, available data suggest that the anti-inflammatory cytokine interleukin (IL)-10 and the mainly proinflammatory cytokines IL-6 and tumor necrosis factor-alpha (TNF-alpha) may play important roles in the development of Th imbalance, CVD and wasting in the uremic milieu. Given the strong association between proinflammatory cytokines and complications common in ESRD, such as vascular calcification and wasting, the potential role of both general and targeted anticytokine treatment strategies in ESRD patients needs further evaluation.