[Peripheral vascular disease: prevalence, mortality and relationship with inflammation in hemodialysis]

Peripheral vascular disease (PVD) is a common disease among patients undergoing hemodialysis leading to increase morbidity and mortality with a high risk of inflammation and sepsis. The aim of the present study was to determinate PVD prevalence in our hemodialysis population and association with inflammation. The study sample consisted of 220 patients prevalents in hemodialysis. A basal study was made in 2001 and a follow up for 47 months. Data were collected retrospectively. PVD diagnosis was made attending to limb pulses and doppler in revisions. Diagnosis was classified as rest pain, ischemic ulceration and gangrene. Among a total of 220 patients, 89 had prevalent PVD. Thirty per cent had rest pain, 6,5% had ischemic ulceration and 3% had gangrene. Ninety five per cent underwent medical treatment, 0,5% were treated by percutaneous transluminal angioplasty (PTA), 2% were treated with surgical revascularization and 2,5% were treated with amputation. Patients with PVD were older, with higher Charlson index, diabetes, they hay higher CRP and fibrinogen serum levels; and lower albumin and prealbumine serum levels. Survival PVD was decreased in Kaplan-Meier (log rank =12,4; p<0,000). Adjusted Cox regression analysis revealed that PVD (p =0,034; OR =2,10; IC [1,06 ; 4,23]) ; age (p =0,001; OR =1,06; IC [1,03 ; 1,09]) and low serum albumin levels (p =0,012; OR =0,93; IC [0,89 ; 0,98]) predicted significantly the risk of mortality. PVD is an independent mortality risk factor in hemodialysis patients. An early diagnosis and treatment are able with examination and doppler. In our sample, a few patients are treated with PTA or surgical revascularization. There is an association between PVD and inflammation.

[On-line sequential hemodiafiltration (HDF-OL-S): a new therapeutic option]

BACKGROUND

on line haemodiafiltration provides the greatest clearance for low and high-molecular weight uremic toxins, which is associated with a lower risk of mortality in our patients. Nowadays, there's increasing evidence about the need of achieving at least 20 litters ultrafiltration in postdilution mode and 70% reduction of beta-2-Microglobulin (B2M), however it requires a vascular access's high blood flow. Unfortunately, we do not succeed in these objectives because of our patients being older, diabetic and with poor vascular access; in this situation high blood flows are more difficult to get at the expense of lower post-dilution exchange volumes. The aim of this study was to assess the efficiency of OL-S-HDF to obtain an equivalent ultrafiltration volume as 20 L in OL-postdilution-HDF (OL-P-HDF). OL-S-HDF initially begins in postdilution mode changing to predilution once the transmembrane pressure (TMP) reached 250 mmHg.

METHODS

we performed one high-flux HD session (HF-HD), one OL-P-HDF session and one OL-S-HDF session in each of the 16 adult patients who participated during 3 consecutive weeks. We compared the clearance rates of low and middle molecules such as urea, creatinine, B2M, myoglobulin and levels of albumin and haematocrit between the 3 different techniques. We measured the pre-filter pressure (PFP) by a manometer set before the dialyzer.

RESULTS

The main characteristics of the sessions are described in table N1. There wasn't significant difference in Kt/V, urea and creatinine removal between the three techniques. B2M and myoglobulin's clearance rates were significantly higher in both hemodiafiltration modes than in HF-HD (p=0.000), however we didn't find differences between OL-P-HDF and OL-S-HDF. There was a direct correlation between PFP and TMP along the sessions in every technique (p<0.05). We found that PFP was better than TMP to correlate with pre-dialysis levels of albumin and haematocrit and also with the haemoconcentration percentage at the end of the sessions.

CONCLUSIONS

This study confirms that OL-S-HDF is as good as OL-P-HDF and it could be a useful technique to treat patients with suboptimal access's blood flow to get to achieve ultrafiltration volumes within the objectives. PFP could offer extra information than TMP.

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.

[Clinical and analytical changes in hemodialysis without acetate]

BACKGROUND

the purpose of this study was to evaluate blood acetate levels and its correlation with clinical and analytical changes in hemodialysis patients treated with standard bicarbonate dialysate compared to treatment with acetate-free bicarbonate dialysate.

METHODS

fourteen patients on hemodialysis (11 male) with mean age of 61 15 years, were treated with conventional bicarbonate dialysate for 1 month and then switched to acetate-free bicarbonate dialysate for another month. Blood samples were drawn at the third session of first and fourth week of each type of dialysis.

RESULTS

Pre-dialysis blood acetate levels were similar in both groups, whereas post-dialysis blood acetate levels were higher in patients treated with conventional bicarbonate dialysate (0.48+/- 0.64 vs. 0.18+/-0.23 mmol/L, p=0.024). Moreover, both periods had similar percentage of patients with pre-dialysis blood acetate levels in the pathologic range, whereas this percentage was higher in post-dialysis samples from patients treated with conventional bicarbonate dialysate respect to acetate-free dialysate (67% vs. 21%, p=0.001). Serum levels of interleukin-6 were statistically higher in the period with conventional bicarbonate dialysate (31.7+/- 24.7 vs. 18.7+/- 10.3 pg/ml, p=0.014), even though other inflammatory markers such as LBP, TNF- and CRP failed to increase in the same period. We didn't found significant differences in the other parameters studied except for the changes in serum concentrations of sodium, chloride and bicarbonate.

CONCLUSIONS

Acetate-free bicarbonate dialysate does not expose patients to a big amount of acetate and allows that the majority of patients finished hemodialysis with blood acetate levels in the physiologic ranges. Acetate-free dialysate was safe and well tolerated by our hemodialysis patients, although clinical advantages derived from its use should be evaluated in long-term prospective studies.

Progression of secondary hyperparathyroidism involves deregulation of genes related to DNA and RNA stability

BACKGROUND

Renal secondary hyperparathyroidism in its late stages becomes autonomous, so excessive parathyroid hormone (PTH) secretion no longer responds to physiologic stimuli or to aggressive medical treatment.

METHODS

To gain molecular understanding of progression of renal secondary hyperparathyroidism, normal and hyperplastic parathyroid tissue with diffuse and nodular growth were analyzed. The results were also compared to parathyroid adenomas. The analysis was performed by high-density oligonucleotide microarray and bidirectional subtraction library.

RESULTS

Analysis of the DNA arrays found 16 overexpressed and 132 repressed genes in the nodules while the subtraction library produced 34 overexpressed and 40 repressed genes. The differentially expressed genes between diffuse and nodular samples included some related to DNA stability and repair (TALDO1, PRDX2, DDB1, XRCC1, and POLB), RNA stability and degradation (OASL and AUF1), protein synthesis and processing (PFDN5, HSPD1, and NACA), cell growth (CDC25C and GRPR), and tumorigenesis and cell cycle (VIL2 and TPD52).

CONCLUSION

According to the function described for the deregulated genes, when secondary hyperparathyroidism becomes autonomous and refractory to treatment, RNA degradation may be increased while DNA integrity may be compromised. These two mechanisms, combined with deregulation of genes related to growth and differentiation show the complex pathway of parathyroid glands' evolution in renal hyperparathyroidism and may explain the large amount of molecular cytogenetic aberrations found in refractory hyperparathyroidism. Considering that some of the genes with altered expression in nodular hyperplasia lead to irreversible consequences in the genomic integrity of the cells, an adequate and early management of the secondary hyperparathyroidism of chronic kidney disease becomes mandatory.

Psychosocial Factors and Health-Related Quality of Life in Hemodialysis Patients

Several sociodemographic and clinical variables are known to influence the health-related quality of life (HRQOL) of patients with kidney disease, yet the relationship between psychological factors and the HRQOL measured by the Kidney Disease Quality of Life Short-Form (KDQOL-SF) is incompletely understood. The objective of this study was to examine the relationship between psychosocial status (depressive symptoms, trait anxiety, and social support) and KDQOL-SF scales in hemodialysis (HD) patients by controlling the effects of sociodemographic and clinical variables. The HRQOL of 194 patients from 43 dialysis centers in Spain was assessed by completing the KDQOL-SF, and evaluating depressive Symptoms (Cognitive Depression Index), trait anxiety (Trait Anxiety Inventory) and degree of social support (Scale of Perceived Social Support). We also recorded several sociodemographic and clinical variables. Two regression models were estimated for each of the 19 scales in the KDQOL-SF. In the first model, we only included sociodemographic and clinical-factors, while the second model also took into consideration psychosocial variables. These last factors (trait anxiety and depressive symptoms, not social support) were found to increase the proportion of explained variability, with highest standardized regression coefficients observed for most KDQOL-SF scales. Depressive symptoms were related to a poor HRQOL when there was a strong physical component, while trait anxiety was mainly related to emotional upset and social relationships. We were able to conclude that trait anxiety and depressive symptoms are strongly associated with the HRQOL assessed by the KDQOL-SF in HD patients. The effects of these factors should therefore be considered when evaluating the quality of life of this type of patient.

Presence of a failed kidney transplant in patients who are on hemodialysis is associated with chronic inflammatory state and erythropoietin resistance

Patients returning to hemodialysis (HD) after failure of their kidney transplant suffer from high morbidity and mortality rates. It is common practice to keep failed kidney transplants in place. It is not known if these failed kidney transplants induce an inflammatory state that contributes to morbidity and mortality. In a single facility, patients starting on HD with failed kidney transplant were identified (Group A) and screened for the presence of chronic inflammatory state. Those with clinical symptoms attributed to the failed allograft (Group A1) were not offered transplant nephrectomy unless deemed necessary during follow-up. Their clinical and laboratory data were followed up for 6 months. Similar data were obtained from a group of incident HD patients (Group B). Forty-three patients had a failed Kidney transplant (Group A). Of these, 29 comprised Group A1 and 14 Group A2. Group B comprised 121 patients. In comparison with Group B, Group A exhibited worse anemia and erythropoietin resistance index (ERI), had lower serum albumin and prealbumin, and higher CRP. Group A1 had lower Hb and higher ferritin, CRP, and ESR in comparison with Group A2. Following transplant nephrectomy, Group A1 had improvement in ERI, serum albumin, prealbumin, ferritin, fibrinogen, CRP, and ESR. At 6 months, Group A1 had higher Hb and serum albumin levels, and lower CRP and ERI in comparison with Group A2. Group B parameters showed no change during follow-up. Patients returning to HD following failure of their kidney transplant suffer from a chronic inflammatory state. Resection of failed transplants in symptomatic patients is associated with amelioration of markers of chronic inflammation. Transplant nephrectomy should be considered a treatment option for patients with failed kidney transplants, especially if they exhibit signs and symptoms of chronic inflammatory state.

[Differences in health-related quality of life between male and female hemodialysis patients]

BACKGROUND

Previous studies in renal patients have reported that women perceive a lower health-related quality of life (HRQOL) than men: however, these studies have been carried out without taking into account the gender-related differences shown in general population samples. The aims of the present study are: a) to define the HRQOL dimensions in which there are differences between men and women on chronic hemodialysis (HD), correcting then the differences on the generic dimensions by means of standardization by age and gender of the obtained scores, using Spanish normative data, and b) to identify the variables that cause these possible gender-related differences on HRQOL.

METHODS

A cross-sectional multi-center study was carried out with 152 patients (69 men and 83 women) receiving HD treatment in 43 Spanish centers, using the KDQOL-SF to evaluate their HRQOL. The generic KDQOL-SF scores were standardized by age and gender using Spanish normative data. Sociodemographic, clinical and psychosocial variables were also collected on each patient. A MANOVA was carried out to study the variables associated with the gender-related differences on HRQOL. The sociodemographic, clinical and psychosocial variables showing significant differences between men and women in the previous univariate analysis were entered as covariates.

RESULTS

The KDQOL-SF scores showed statistically significant differences between men and women in four scales: physical functioning, emotional role limitation, social function and emotional well-being. In contrast, standardized scores showed no differences between men and women in the profile or degree of HRQOL impairment. Although statistically significant gender-related differences were shown in educational level, employment, haemoglobin, Kt/V, trait anxiety and depressive symptoms, only the last two variables showed an independent effect on the differences in HRQOL.

CONCLUSION

Impaired HRQOL in women on HD reflects the gender-related differences that are also shown in the general population, and they are related to the higher prevalence of trait anxiety and depressive symptoms in women.

Psychosocial factors and quality of life in young hemodialysis patients with low comorbidity

BACKGROUND

The current predominance of older patients, diabetic patients and high-comorbidity patients among the hemodialysis (HD) population has probably influenced the definition of the effects of renal disease on health-related quality of life (HRQOL), and these effects can be different in the patient subgroup without these characteristics. This multicenter study aimed to assess HRQOL in non-diabetic HD patients, aged < 65 yrs and with low comorbidity, and to study the effects of the demographic, clinical and psychosocial characteristics on their HRQOL.

METHODS

117 patients from 43 Spanish HD centers participated in the study. Patients completed the Kidney Disease Quality of Life Short-Form questionnaire (KDQOL-SF) and screening for depressive symptoms, anxiety symptoms and social support. Various sociodemographic and clinical variables were also recorded.

RESULTS

HD patients' HRQOL showed a profile similar to that of the general HD population, with low physical health scores, but normal mental health scores. Multivariate analysis demonstrated that gender, older age, non-working status, low social support and low levels of hemoglobin (Hb), Kt/V or protein catabolic rate (PCR), had a negative effects, but these effects were of relatively small magnitude and appeared only in some scales. The most important independent predictors of HRQOL were anxiety state and depressive symptoms.

CONCLUSIONS

In non-diabetic HD patients, aged < or = 65 yrs and with low comorbidity, psychological factors (anxiety state and depressive symptoms) are crucial HRQOL determinants. These variables should be considered when assessing HRQOL in HD patients with these demographic and clinical characteristics.

Comparative study of the expression of proteins involved in the cell cycle in renal secondary hyperparathyroidism

BACKGROUND

In renal hyperparathyroidism, parathyroid cell proliferation seems to play a key role in the progression of the disease. Therefore, G1/S transition, a main cell cycle regulatory step, could be deregulated in these patients.

METHODS

One hundred and one parathyroid glands, taken from parathyroidectomies performed on 41 patients on hemodialysis (HD), and 15 glands, taken from 7 patients with post-transplantation persistent hyperparathyroidism (HPT), were studied. Twelve normal parathyroid (PT) glands were used as the control. Biochemical data, immunohistochemical (IHC) profiles of G1/S transition regulators belonging to the two main pathways (cyclin D1/p16INK4A/pRb and p14ARF/p53/MDM2), and proliferation rate (Ki67) were correlated.

RESULTS

All of the other proteins differed from normal IHC profiles in both groups that showed significant higher proliferating rates, decreases in p27KIP1, pRb, and cyclin D1, as well as increases in p16INK4A, p53, MDM2, and p21WAF1 levels, in comparison with normal PT glands, with the exception of cyclin D3. Contrary to patients with HPT who were on hemodialysis, in post-transplantation HPT, consistent correlations between biochemical data and IHC profiles were obtained.

CONCLUSION

In both groups IHC profiles of proteins involved in G1/S transition regulation significantly differed from normal PT glands. The results support partial reversion to normal IHC profile in post-transplantation HPT.

Parathyroidectomy: whom and when?

Hyperparathyroidism (HPT) is common in patients on dialysis, and parathyroidectomy (PTx) is often required. We present a retrospective, descriptive analysis of data corresponding to 148 patients on dialysis undergoing PTx due to severe refractory HPT (PTH 1401 +/- 497 pg/mL, Ca 10.6 +/- 0.8 mg/dL, P 6.9 +/- 1.7 mg/dL). Demographic data were compared with those recorded in 309 patients on dialysis not subjected to PTx who were managed at the same hospital. In the PTx group, the factors age (49.3 +/- 14 years), male gender (48.6%), and diabetes (0.7%) were significantly lower than in the non-PTx group (61.5 +/- 14.9 years, male gender 59%, diabetes 19.4%), while time on dialysis was longer (8.6 +/- 5.8 vs. 5.5 +/- 5.4 years). In 129 of the study patients (87.4%), four or more glands were identified, and total PTx plus autotransplantation (AT) in the forearm was performed. In the remaining 19 patients, two to three glands were identified, and AT was not undertaken. Four of the 19 patients were successfully operated on again for persistent HPT, seven showed PTH levels <250 pg/mL, and eight maintained severe HPT. Perioperative complications included one death due to cardiac insufficiency, two repeat operations due to bleeding, and one patient with chronic hoarseness. Hospital stay was prolonged in 20% of patients due to a hungry bone syndrome. Among those patients with PTx and AT, HPT recurred in 21 patients (16.2%) at 3.1 +/- 2.3 years. In 13 of these patients, autograft was removed at 7.5 +/- 2.9 years. Serum calcium and phosphate levels improved after PTx, and these results were maintained for 5 years (9.6 +/- 0.8 and 4.2 +/- 1.2 mg/dL, respectively). In conclusion, PTx with AT is a safe option for the treatment of severe HPT that is accompanied by low morbidity and mortality and a good outcome. Medical treatment should not be prolonged at the expense of long repeated bouts of hypercalcemia and/or hyperphosphatemia with their irreversible consequences.

Chromosomal aberrations, the consequence of refractory hyperparathyroidism: its relationship with biochemical parameters

BACKGROUND

It has been shown that refractory hyperparathyroidism (HPT) correlates biologically with a monoclonal true neoplasm, but the chromosomal changes and their relationship with biochemical variables such as high levels of phosphate, low levels of calcium (Ca), and calcitriol deficiency are still in need of a deeper analysis.

METHODS

Comparative genomic hybridization was used to scan for DNA copy number changes in two groups of samples: 57 glands from refractory secondary HPT and 28 glands from refractory HPT after kidney transplantation. Biochemical HPT-related parameters from these patients were collected and analyzed.

RESULTS

Sixty-one percent of the glands from dialysis patients and 53.6% of the glands from transplanted patients suffering severe secondary hyperparathyroidism had clonal chromosomal imbalances. Losses were far more common than gains. The most recurrent changes were losses of 1p (71%), monosomies of chromosomes 19 and 22 (45%), and losses of 20q (44%) and 16p (42%). The most frequent gains were 5q, 6q, and 13q. Biochemical parameters suggested that Ca excess is related to the development of these chromosomal aberrations, although it is not known if it is by playing a role in producing the alterations or merely as a reflection of HPT severity. Phosphate levels, despite their known effect in increasing the proliferation of the parathyroid glands, were not related to the chromosomal aberrations found in severe secondary HPT.

CONCLUSION

Clonal recurrent chromosomal changes are present in more than half of the glands from patients with refractory HPT, which undergo extreme biochemical levels in hyperparathyroidism effectors. These changes support the idea of the monoclonal neoplastic nature of this disorder.

[Cardiovascular risk factors in chronic renal failure]

Cardiovascular complications are the main cause of death in patients with chronic renal disease. These complications are due to two important morphological changes. Firstly, left ventricular hypertrophy together with the changes in the cardiac remodelling and myocardiac fibrosis constitute the lesion with the highest incidence in renal chronic disease. Secondly, disease in the large arteries (macrovascular disease) involve two types lesions: Artherosclerosis, which is characterised by the formation of plaques in the intima arterial membrane and artherosclerosis due to lesions in the media arterial membrane, which causes a loss in elasticity of the arterial tree.

Changes in quality of life after renal transplantation

The objective of this study was to evaluate the modifications that renal transplantation produces on the quality of life (QOL) of patients with chronic renal failure (CRF) previously undergoing hemodialysis (HD) and to analyze the possible factors implicated. A multicenter study of QOL was performed on 1,023 patients undergoing dialysis, using as QOL indicators the Karnofsky Scale (KS) and the Sickness Impact Profile (SIP). Among this group, 93 patients received a renal transplant and QOL was re-studied in them; each subject, therefore, was his own control. In the 88 patients with a functioning graft, an improvement in QOL indices was globally observed; this improvement was much more marked in men than in women, for unclear reasons. Older age and greater prior comorbidity diminished the beneficial effects of transplantation.