Elevated C-reactive protein in older people

Prosthetic joint infections in the elderly

INTRODUCTION

Recent age-projection showed that the number of elderly is expected to rise significantly over the next decades worldwide. Accordingly, the prevalence of chronic and degenerative diseases will increase, among them osteoarthritis, resulting in more and older patients undergoing total joint arthroplasty and thereby also being at risk for associated complications. Among those, prosthetic joint infections are feared as threatening complication with a mortality approaching 8 % and causing long-term antibiotic therapy, immobilization and often account for operative revision.

MATERIALS AND METHODS

This review summarizes epidemiological, microbiological, and therapeutic aspects of prosthetic joint infection in the elderly population.

CONCLUSION

Considering the increase in the number of PJIs in the forthcoming years in most countries, a common action to reduce the associated morbidity and mortality is strongly encouraged in Europe.

Serum 25-hydroxyvitamin D levels modulate the acute-phase response associated with the first nitrogen-containing bisphosphonate infusion

The acute-phase response (APR) is the most frequent side effect after the first dose of intravenous nitrogen-containing bisphosphonates (N-BPs). It has been demonstrated in vitro that N-BPs stimulate gammadelta T-cell proliferation and production of cytokines and that vitamin D is able to modulate them. Therefore, we have studied the relationship between bone metabolism parameters, particularly for 25-hydroxyvitamin D [25(OH)D], and APR in patients treated with 5 mg zoledronic acid intravenously. Ninety N-BP-naive osteoporotic women (63.7 +/- 10.6 years of age) were stratified for the occurrence of APR (APR(+)) or not (APR(-)) and quantified by body temperature and C-reactive protein (CRP). The APR(+) women had significantly lower 25(OH)D levels than the APR(-) women. Levels of 25(OH)D were normal (>30 ng/mL) in 31% of APR(+) women and in 76% of APR(-) women. The odds ratio (OR) to have APR in 25(OH)D-depleted women was 5.8 [95% confidence interval (CI) 5.30-6.29; p < .0002] unadjusted and 2.38 (95% CI 1.85-2.81; p < .028) after multiple adjustments (for age, body mass index, CRP, calcium, parathyroid hormone, and C-telopeptide of type I collagen). Levels of 25(OH)D were negatively correlated with postdose body temperature (r = -0.64, p < .0001) and CRP (r = -0.79, p < .001). An exponential increase in fever and CRP has been found with 25(OH)D levels lower than 30 ng/mL and body temperature less than 37 degrees C, whereas normal CRP was associated with 25(OH)D levels above 40 ng/mL. The association between post-N-BPs APR and 25(OH)D suggests an interesting interplay among N-BPs, 25(OH)D, and the immune system, but a causal role of 25(OH)D in APR has to be proven by a randomized, controlled trial. However, if confirmed, it should have some practical implications in preventing APR.

Serum C-reactive protein at admission predicts in-hospital mortality in medical patients

BACKGROUND

Previous studies have examined the role of inflammatory markers in patients with coronary heart disease, stroke, chronic renal failure and other selected patient populations. The aim of this study was to assess the clinical utility of serum C-reactive protein (CRP) at admission in predicting outcome in hospitalized medical patients.

METHODS

All patients admitted to our medical department were eligible to be included in the study. At the time of admission, demographic and clinical information was obtained. CPR was measured within 12 h of hospitalization. The results were analyzed using Cox proportional hazards multiple regression model.

RESULTS

Three hundred eighty-two patients were included in the study (186 males and 196 females). Age (mean+/-standard deviation) was 70.8+/-15.7 years. Serum CRP [median (interquartile range) at admission was 29.7 mg/l (6.6-114.3). Serum CRP at admission was independently associated with in-hospital death. Levels above 120 mg/l increased the probability of fatal outcome three fold (hazard ratio=2.98, 95% confidence interval: 1.35-6.58). In patients older than 80 years, CRP at admission was a stronger predictor of in-hospital death (hazard ratio=5.41, 95% confidence interval: 1.38-21.26).

CONCLUSIONS

Serum CRP at admission is an independent predictor of mortality in hospitalized patients, particularly in the elderly. Admission CRP higher than 120 mg/l was associated with increased probability of in-hospital death (three fold in the overall population and five fold in the elderly subgroup) compared with lower levels.

Secondary hyperparathyroidism promotes the acute phase response – a rationale for supplemental Vitamin D in prevention of vascular events in the elderly

Parathyroid hormone (PTH) promotes IL-6 secretion by osteoblasts, and may also up-regulate IL-6 production in the liver and adipose tissue; this may explain why serum IL-6 is markedly elevated in primary hyperparathyroidism, and low in hypoparathyroidism. IL-6 is the chief stimulus to hepatic production of many acute phase reactants, notably fibrinogen and C-reactive protein (CRP). Mild secondary hyperparathyroidism is common in elderly people, particularly at high latitudes during the winter, owing to poor vitamin D status. This may rationalize evidence that acute phase proteins show seasonal variations and are typically elevated in the elderly, whereas leisure physical activity is associated with a reduction in these proteins. In a recent clinical trial targeting elderly chronically ill patients, administration of vitamin D reduced serum levels of both CRP and IL-6; further such studies should assess the impact of physiologically meaningful doses of vitamin D on acute phase reactants in elderly subjects likely to have poor vitamin D status. Since elevations of CRP and fibrinogen may increase risk for thromboembolic vascular events, these considerations may help to explain the excess of coronary mortality observed during winter months, and suggest a role for supplemental vitamin D in preservation of vascular health. Moderate alcohol intake is associated with reduced serum PTH as well as decreased levels of CRP and fibrinogen; conceivably, modulation of PTH mediates, at least in part, the favorable impact of moderate drinking on the acute phase reactants.

Acute phase protein levels and thymus, spleen and plasma protein synthesis rates differ in adult and old rats

Aging induces a dysregulation of immune and inflammation functions that may affect protein synthesis rates in lymphoid tissue and plasma proteins. We quantified in vivo synthesis rates of thymus, spleen and plasma proteins, including albumin and acute phase proteins, in adult (8 mo old) and old (22 mo old) rats using the flooding dose method [L-(1-(13)C) phenylalanine]. Immunosenescence was reflected by thymus atrophy and spleen hypertrophy in old rats but not in adult rats. A low albumin plasma level associated with high concentrations of fibrinogen, alpha(2)-macroglobulin, alpha(1)-acid glycoprotein and proteins other than albumin revealed a low grade inflammation in old rats. Protein fractional synthesis rates (FSR) and protein synthesis efficiencies of thymus were 29 and 26% lower in old than in adult rats, respectively; these variables did not differ in spleen. Protein absolute synthesis rates (ASR) of the thymus and spleen were 76% lower and 67% greater in old than adult rats, respectively. The FSR and ASR of albumin and other plasma proteins were greater in old than in adult rats. Protein synthesis measurement is a valuable nonimmunological tool to assess, in vivo, immune and inflammatory variables. Alterations in secondary lymphoid organs and plasma protein synthesis may contribute to the significant repartitioning of amino acids in old compared with adult rats and may be involved in sarcopenia.

Ageing and infection

Average life expectancy throughout developed countries has rapidly increased during the latter half of the 20th century and geriatric infectious diseases have become an increasingly important issue. Infections in the elderly are not only more frequent and more severe, but they also have distinct features with respect to clinical presentation, laboratory results, microbial epidemiology, treatment, and infection control. Reasons for increased susceptibility include epidemiological elements, immunosenescence, and malnutrition, as well as a large number of age-associated physiological and anatomical alterations. Moreover, ageing may be the cause of infection but infection can also be the cause of ageing. Mechanisms may include enhanced inflammation, pathogen-dependent tissue destruction, or accelerated cellular ageing through increased turnover. In most instances, treatment of infection leads to a satisfactory outcome in the elderly. However, in palliative care situations and in patients with terminal dementia, the decision whether or not to treat an infectious disease is becoming a difficult ethical issue.

Evidence for an alteration of plasma and liver proteins response to dexamethasone in aging rats

The aim of this study was carried out to analyse the liver and plasma proteins response to dexamethasone in adult (6-8 months) and old (24 months) rats in order to ascertain the involvement of glucocorticoids in the aging process. The animals received dexamethasone (Dex) for 5 or 6 days. As Dex decreased food intake, all groups were pair fed to dexamethasone-treated old rats. The synthesis of mixed plasma and liver proteins (assessed by a flooding dose of [13C] valine) was similarly greatly improved in adult and old rats after Dex treatment. However, the level of mixed plasma proteins was only slightly increased. When specific plasma proteins were assessed, a similar increase in the concentration of albumin and alpha1 acid glycoprotein was observed in adult and old rats. By contrast, fibrinogen decreased to a greater extend in old rats and alpha2 macroglobulin became undetectable in old animals. It was concluded that the response of plasma and liver proteins to Dex was altered in old rats and may contribute to the pathogenesis of several diseases which occur during aging.