Anemia of uremia is associated with reduced in vitro cytokine secretion: immunopotentiating activity of red blood cells

Importance of hemoglobin concentration and its modification for the outcome of head and neck cancer patients treated with radiotherapy

INTRODUCTION

Hypoxia induced radioresistance has been acknowledged for decades. One of the indirect evidences of the influence of hypoxia on radiation response comes from the observations of a correlation between tumor control and hemoglobin level. This review examines the clinical data on the prognostic and predictive role of hemoglobin level and hemoglobin manipulation in radiotherapy of squamous cell carcinomas of the head and neck, a tumor type where hypoxic radioresistance have been previously documented.

THE INFLUENCE OF HEMOGLOBIN CONCENTRATION ON TUMOR OXYGENATION AND OUTCOME

The aim is to evaluate the existing literature for information of the influence of hemoglobin concentration and hemoglobin modifications on tumor oxygenation and outcome in head and neck squamous cell cancer patients. The data from several randomized trials show that while most studies have confirmed the prognostic value of hemoglobin, increasing the hemoglobin level through transfusion or erythropoietin stimulation did not result in improved outcome for patients with low initial hemoglobin levels. Clinical studies showed that smoking reduced the oxygen carrying capacity of the blood through formation of carboxyhemoglobin, and lead to poorer response to radiotherapy in smokers compared to non-smokers. Smoking also increased the risk of the development of secondary cancers.

CONCLUSION AND FUTURE PERSPECTIVES

In conclusion, low hemoglobin is a significant negative prognostic factor for radiotherapy of head and neck cancer. Correction of pre-treatment low hemoglobin by blood transfusion and/or erythropoietin stimulating agents does, however, not improve the outcome. Smoking leads to a decrease in effective hemoglobin and poorer treatment outcome. Smoking should be avoided in order to improve the therapeutic efficacy of radiotherapy and development of other smoking-related diseases and/or secondary cancers.

Cutaneous warts in children before and after renal transplantation

Cutaneous warts occur in 3.9-4.9% of children in the UK. The incidence is increased in organ transplant recipients and may be increased in patients with chronic kidney disease (CKD), since uraemia reduces the immune system's function. We surveyed the records from our CKD and renal transplant clinic to ensure patients with warts were identified and appropriately treated. Data were collected by questionnaire. The presence of warts, location, treatment, levels of pain and emotional upset were recorded. Nine of 49 (18.4%) pre-transplantation patients (33 male, median age 12.1 years) were currently suffering from warts compared with 17 of 60 (28.3%) post-transplantation patients (34 male, median age 13.9 years). A further 14 pre-transplantation and 16 post-transplantation patients had previously suffered from warts which had resolved. Forty-one patients had sought treatment for warts, mainly from primary care. Five patients, all having received transplants, were seen by a dermatologist. Self-rated levels of pain and emotional upset were generally low, apart from those of four adolescent patients who expressed significant emotional upset. We concluded that cutaneous warts are more common among CKD patients. Appropriate information and treatment are required before and after transplantation. The majority of warts can be treated in primary care, but selected patients with extensive warts that cause distress need early referral for dermatology opinion.

Chronic kidney disease (CKD) in the elderly -- a geriatrician's perspective

Chronic kidney disease (CKD) is becoming increasingly prevalent among many different populations all over the world, including the US and Europe. Its multitude of complications with devastating outcomes leads to a significantly higher risk for cardio-vascular and all-cause mortality in an individual. However, it is clear now that early detection of CKD might not only delay some of the complications but also prevent them. Therefore, various important public health organizations all over the world have turned their focus and attention to CKD and its risk factors, early detection and early intervention. Nevertheless, the general goals in preventing the increase in CKD and its complications are far from being completely achieved. Why is this so? What is the magnitude and complexity of the problem? How is it affecting the population - are there differences in its affection by age, gender or frail elderly versus the robust? Are we modifying the risk factors appropriately and aggressively? Are there subtle differences in managing the risk factors in those on dialysis versus the non-dialysis CKD patients? Is it important to treat anaemia of CKD aggressively, will it make a difference in the disease progression, its complications or to quality of life? What do these unfortunate individuals commonly succumb to? What do we advise patients who refuse dialysis or those who desire dialysis or transplant? Are there useful non-dialytic treatment recommendations for those who refuse dialysis? What is the role of the physicians caring for the elderly with CKD? When should the primary care givers refer a CKD patient to a nephrologist? The key to eventually controlling incident and prevalent CKD and improve quality of life of affected individuals, lies in not only knowing these and many other vital aspects, but also in applying such knowledge compulsively in day-to-day practice by each and every one us. As CKD is increasingly a disease of the elderly with men being affected more, this review details fairly comprehensively the vital aspects of CKD, especially from a primary care geriatrician's practical standpoint.

Anemia management in chronic kidney disease

Anemia is common in chronic kidney disease (CKD) due to a state of erythropoietin deficiency. Erythropoietin therapy has been used for approximately 20 years to correct anemia in CKD and to improve both subjective and objective outcomes. Guidelines that establish a hemoglobin (Hb) goal for anemia correction in CKD patients are largely based on observational data. Controversy still exists, however, because outcomes have not been consistent with various degrees of anemia correction. The number of prospective randomized trials investigating the effects of anemia correction on cardiovascular (CV) morbidity and mortality in CKD patients, an already high-risk group, is limited. With respect to improving CV outcomes in the CKD population, the currently available trial data caution against raising Hb levels in CKD patients to approach more "normal" physiologic ranges. The disappointing experience with the trial data must be weighed against the beneficial associations of erythropoietin therapy that have been generated from observational data. Establishing the ideal target Hb ranges for anemia correction in CKD patients remains a dynamic process and leaves many gray areas to be further elucidated. Here, we present a case that underscores the need to consider the study design when reviewing the data at a population level in order to determine what is most appropriate for our patient.

Erythropoietin treatment in advanced multiple myeloma is associated with improved immunological functions: could it be beneficial in early disease?

Erythropoietin (Epo) is the main growth regulator of red blood cells, and recombinant human erythropoietin (rHuEpo) is thus used in clinical practice for the treatment of anaemia, primarily in kidney disease and cancer. rHuEpo treatment was found to be associated with prolonged survival of multiple myeloma (MM) patients. This clinical observation was then supported by studies on murine myeloma models. It thus appeared that rHuEpo had an anti-myeloma effect, causally related to an immunomodulatory function of rHuEpo. The present study investigated whether rHuEpo-treated MM patients acquire improved immunological functions. Treatment with rHuEpo, prescribed for anaemia that occurs in advanced disease, was associated with effects on a variety of immunological parameters and functions. This was expressed in an actual normalisation of the CD4:CD8 cell ratio, enhanced T cell phytohaemagglutinin-mediated activation and proliferation potential, T cell expression of the costimulatory CD28 and inhibitory CTLA-4 molecules, as well as reduced interleukin-6 serum values to normal levels. Furthermore, it was demonstrated that immunological abnormalities manifest in patients even in the early stages of MM. Our findings thus suggest that rHuEpo treatment might be effective in the early stages of MM, before anaemia develops. It is expected that this would boost the immune system, consequently achieving an anti-myeloma function; affecting disease progression and improving the prognosis.

Poststorage Leuko-Depleted Plasma Inhibits T-Cell Proliferation and Th1 Response In Vitro: Characterization of TGFβ-1 as an Important Immunomodulatory Component in Stored Blood

BACKGROUND

Poststorage, leuko-depleted blood transfusions have been associated with increased postoperative infections and improved allograft survival compared with prestorage leukocyte-depleted blood transfusion. Although the mechanism of this phenomenon remains to be fully elucidated, it is clear that the immunomodulatory effect is mediated by leukocytes/platelets or their products.

METHOD

The aim of this study was to investigate the in vitro effects of pre- and poststorage leuko-depleted plasma (LDP) and buffy coat LDP on T-cell proliferation and cytokine synthesis using multiparameter flow cytometry.

RESULTS

In cell cultures exposed to prestorage LDP and buffy coat LDP there were no significant changes compared with fresh blood. In cell cultures exposed to poststorage LDP, T-cells showed reduced expression of CD69, CD25 (IL-2Ralpha), CD122 (IL-2Rbeta) and CD132 (IL-2Rtau) and production of TNF-alpha and IL-2 but there was no significant alteration for IFN-tau or IL-4. Changes in cytokine/cytokine receptor synthesis and T-cell proliferation were shown to be directly proportional to poststorage LDP concentration. Some of these changes were characteristic of TGFbeta-1. Addition of TGFbeta-1 neutralising antibody to poststorage LDP, negated the immunosuppressive effect on PHA-stimulated PBMC cultures.

CONCLUSIONS

The decrease in T-cell proliferation and Th1 cytokines TNF-alpha and IL-2, may be one basis of altered immunoregulation resulting in increased rates of certain types of infections and increased graft tolerance reported in patients receiving poststorage LD blood transfusions. TGFbeta-1 is a major immunomodulatory component of poststorage LD blood transfusions.

Chronic kidney disease progression in native and transplant kidneys

PURPOSE OF REVIEW

The present review addresses the recent literature demonstrating important differences in the rate of progression of kidney function decline between transplant recipients and patients with native kidney disease. It also highlights the need for prospective studies to determine the importance of nonimmune factors that are established risk factors for progression of native kidney disease in the transplant setting.

RECENT FINDINGS

Transplant recipients establish modest levels of kidney function but have rates of kidney function decline that are slower than those in patients with native kidney disease. Continued improvements in long-term graft survival have not been achieved despite significant advances in immunosuppression. There is increasing observational evidence that nonimmune factors that play a causal role in progression of native kidney disease may also be important determinants of allograft decline. There are fundamental differences between transplant recipients and patients with native kidney disease that preclude extrapolation of evidence from native kidney disease to the transplant setting.

SUMMARY

Transplant recipients are a unique group of chronic kidney disease patients. Prospective studies to determine the importance of nonimmune factors such as hypertension, proteinuria, dyslipidemia, diabetes, and anemia in the transplant setting are needed.

Pharmacoeconomic considerations in the health system management of anaemia in patients with chronic kidney disease and end stage renal disease

Anaemia is prevalent in patients with chronic kidney disease and end stage renal disease. If left untreated, it greatly affects patient survival, quality of life and functional status. Epoetin and darbepoetin are two biotechnology drugs that effectively stimulate the production of red blood cells. These drugs have been shown to significantly increase haemoglobin concentrations and improve quality of life. So far, there have been no head-to-head pharmacoeconomic studies that have compared epoetin to darbepoetin. Health system decision makers need to evaluate important considerations when comparing these agents. These considerations include drug acquisition costs, the patient population being treated, the location of drug administration (in-patient versus ambulatory) and federal government reimbursement. This review details these important pharmacoeconomic considerations.

Red blood cells promote survival and cell cycle progression of human peripheral blood T cells independently of CD58/LFA-3 and heme compounds

Red blood cells (RBC) are known to modulate T cell proliferation and function possibly through downregulation of oxidative stress. By examining parameters of activation, division, and cell death in vitro, we show evidence that the increase in survival afforded by RBC is due to the maintenance of the proliferative capacity of the activated T cells. We also show that the CD3+CD8+ T cell subset was preferentially expanded and rescued from apoptosis both in bulk peripheral blood lymphocyte cultures and with highly purified CD8+ T cells. The ability of RBC to induce survival of dividing T cells was not affected by blocking the CD58/CD2 interaction. Moreover, addition of hemoglobin, heme or protoporphyrin IX to cultures of activated T cells did not reproduce the effect of intact RBC. Considering that RBC circulate throughout the body, they could play a biological role in the modulation of T cell differentiation and survival in places of active cell division. Neither CD58 nor the heme compounds studied seem to play a direct relevant role in the modulation of T cell survival.

The use of pretransplant erythropoietin to normalize hemoglobin levels has no deleterious effects on renal transplantation outcome

BACKGROUND

The aim of this study was to establish the outcome of renal transplantation in patients given pretransplant erythropoietin (EPO) treatment targeted at reaching a normal hemoglobin concentration (Hb), compared to those given EPO-treatment aimed at maintaining subnormal Hb.

METHODS

A total of 416 patients from Scandinavian countries and with renal anaemia were enrolled to examine the effects of increasing Hb from a subnormal level (90-120 g/liter) to a normal level (135-160 g/liter) by EPO treatment. Half of the patients were randomized to have their Hb increased, with the other half randomized to maintain a subnormal Hb. Thirty-two patients from the normal Hb group and 24 patients from the subnormal group received a renal graft during the study period. The outcomes of these transplantations were examined prospectively for 6 months.

RESULTS

Preoperative Hb levels were 143+/-17 and 121+/-14 g/liter in the two groups, respectively (P<0.0001). The Hb remained higher in the normal Hb group during the first 2 weeks after transplantation. The percentage of patients requiring postoperative blood transfusions in the normal Hb group was 16%, compared with 50% in the subnormal group (P<0.01). No statistically significant difference in the proportion of functioning grafts or in the serum creatinine levels could be detected. No correlation between EPO treatment and creatinine levels after transplantation was found. The frequency of adverse events was similar in the two groups.

CONCLUSIONS

EPO treatment aimed at reaching a normal Hb in renal transplant recipients reduces the postoperative requirement for blood transfusions and has no deleterious effects on kidney graft function.

Effect of pretransplant erythropoietin therapy on renal allograft outcome

Erythropoietin (EPO) is widely used among patients with end-stage renal disease awaiting transplantation. Data suggest that EPO therapy may be immunomodulatory. The purpose of this study was to assess the effects of pretransplant EPO therapy on renal allograft outcome. We evaluated 120 consecutive renal transplant recipients to assess the effect of EPO on graft outcome following renal transplantation. Among the study population, 58 patients were receiving EPO before transplantation (EPO group) and 62 patients were not treated with EPO (non-EPO group). Twenty-four of 58 EPO-treated patients (41%) experienced delayed graft function after transplantation, compared with 11 of 62 (18%) non-EPO-treated patients (P<0.05). The incidence of acute rejection, time to first rejection, and 1-year graft survival rate did not differ between the two groups. In conclusion, pretransplant EPO therapy does not appear to adversely impact on the incidence of acute rejection or 1 year graft survival rate. However, EPO-treated patients may be predisposed to the development of delayed graft function.