Are Lipid Abnormalities Reliable Cardiovascular Risk Factors in Dialysis Patients?

Patients on chronic hemodialysis often present both hyperlipidemia and a high incidence of cardiovascular disease (CVD). Uremic hyperlipidemia has usually been regarded as one of the most important cardiovascular risk factors (CVRF) in these patients. In order to study whether the “uremia-induced” lipid abnormalities are actually associated with evidence of uremic CVD, and consequently may be considered reliable CVRF, 123 patients on chronic dialysis were reviewed for the presence of CVD and, at the same time, examined for their lipoprotein pattern and other clinical and biochemical variables.

Lipids and lipoproteins did not prove helpful in our study in identifying patients with CVD. Despite the fact that they had been on dialysis for a shorter time, CVD patients were significantly older and had higher blood pressure than patients without CVD. Our data suggest that the uremia-induced lipid abnormalities are not reliable markers of CVD in dialysis patients, and support the hypothesis that dialysis per se does not accelerate the atherosclerotic process in uremic patients

The predictive role of interim PET after the first chemotherapy cycle and sequential evaluation of response to ABVD in Hodgkin's lymphoma patients-the Polish Lymphoma Research Group (PLRG) Observational Study

Background

Interim PET after two ABVD cycles (iPET2) predicts treatment outcome in classical Hodgkin's lymphoma. To test whether an earlier assessment of chemosensitivity would improve the prediction accuracy, we launched a prospective, multicenter observational study aimed at assessing the predictive value of iPET after one ABVD (iPET1) and the kinetics of response assessed by sequential PET scanning.

Patients and methods

Consecutive patients with newly diagnosed classical Hodgkin's lymphoma underwent interim PET scan after one ABVD course (iPET1). PETs were interpreted according to the Deauville score (DS) as negative (-) (DS 1-3) and positive (+) (DS 4, 5). Patients with iPET1 DS 3-5 underwent iPET2.

Results

About 106 early (I-IIA) and 204 advanced (IIB-IV) patients were enrolled between January 2008 and October 2014. iPET1 was (-) in 87/106 (82%) or (+) in 19/106 (18%) of early, and (-) in 133/204 (65%) or (+) in 71/204 (35%) of advanced stage patients, respectively. Twenty-four patients were excluded from response analysis due to treatment escalation. After a median follow-up of 38.2 (3.2-90.2) months, 9/102 (9%) early and 43/184 (23%) advanced patients experienced a progression-free survival event. At 36 months, negative and positive predictive value for iPET1 were 94% and 41% (early) and 84% and 43% (advanced), respectively. The kinetics of PET response was assessed in 198 patients with both iPETs. All 116 patients with iPET1(-) remained iPET2(-) (fast responders), 41/82 with IPET1(+) became iPET2(-) (slow responders), and the remaining 41 stayed iPET2(+) (non-responders); progression-free survival at 36 months for fast, slow and non-responders was 0.88, 0.79 and 0.34, respectively.

Conclusion

The optimal tool to predict ABVD outcome in HL remains iPET2 because it distinguishes responders, whatever their time to response, from non-responders. However, iPET1 identified fast responders with the best outcome and might guide early treatment de-escalation in both early and advanced-stage HL.

Aspects of Biocompatibility of Two Different Dialysis Membranes: Cuprophane and Polysulfone

Intradialytic hypoxemia, leukopenia and coagulation system activation were monitored in 9 uremic patients during hemodialysis with cuprophane (Cu) and polysulfone (Psf) membranes, using the following parameters: polymorphonuclear count (PMN), elastase alpha-1 proteinase inhibitor (EI-α1PI) complex, platelet count, β-thromboglobulin (BTG), fibronectin (FN) and arterial oxygen tension (PaO2).

Our results indicate that 1) intradialytic hypoxemia observed with both membranes does not seem to be exclusively related to the well-known membrane-dependent leukopenia; 2) platelet activation, as demonstrated by the plasma BTG increase, appears to be an exclusive cellulosic membrane-related phenomenon; 3) at the same time platelet activation seems to be the major factor responsible for high FN levels, the highest FN levels occurring concurrently with the lowest platelet count.

Cardiovascular risk factors in severe chronic renal failure: the role of dietary treatment

BACKGROUND

Lipoprotein abnormalities and increased oxidized LDL (OxLDL) are often observed in uremia and are reported to play a central role in the development of cardiovascular disease (CVD). Vegan diet, known for its better lipoprotein profile and antioxidant vitamins content, could protect against CVD. Aim of this study was to investigate the influence of vegan diet supplemented with essential amino acids (EAA) and ketoanalogues (VSD) on both traditional and non-traditional cardiovascular risk factors (CVRF).

METHODS

Twenty-nine patients (18 M, 11 F) aged 55 years (range 29-79 years) with advanced chronic renal failure (median sCr: 5.6 mg/dl) on very low protein vegetarian diet (0.3 g/kg/day) supplemented with a mixture of EAA and ketoacids (VSD) and 31 patients (20 M, 11 F) aged 65 years (range 29 - 82 years) on conventional low-protein diet (CD: 0.6 g/kg/day) with a similar renal function (median sCr: 5.2 mg/dl), were investigated for lipids and apolipoprotein parameters (traditional CVRF) as well as for oxidative stress (oxidized LDL, antibodies against OxLDL and thiobarbituric acid-reactive substances (TBARS)), total homocysteine (tHcy), lipoprotein(a) (Lp(a)), albumin and c-reactive protein (CRP) (non-traditional CVRF) including vitamins A, E, B12 and folic acid.

RESULTS

Compared to patients on CD, those on VSD showed increased HDL cholesterol levels (p < 0.005) with a reduction of LDL cholesterol (p < 0.01) and an increase of apoA1/apoB ratio (p < 0.02). Among non-traditional CVRF, a mild but significant reduction of OxLDL (p < 0.05) with lower TBARS concentrations (p < 0.01) and a significant reduction of total homocysteine (p < 0.002), Lp(a) (p < 0.002) and CRP levels (p < 0.05) were also observed in these patients. Concentrations of vitamin E and A were not different between the two groups while vitamin B12 and folic acid resulted markedly increased in patients on VSD. OxLDL significantly correlated with total and LDL cholesterol, triglycerides and Apo B in CD but not in VSD patients. Patients on CD also showed a significant correlation between urea and CRP. After a multivariate analysis, only urea (p < 0.001) and OxLDL (p < 0.006) were associated to a risk of CRP > 0.3 mg/dl.

CONCLUSIONS

These results indicate a better lipoprotein profile in patients on vegan diet including non-traditional CVRF. In particular, these patients show a reduced oxidative stress with a reduced acute-phase response (CRP) as compared to patients on conventional diet. We hypothesize that urea, significantly lower in patients on VSD, may account, possibly together with the reduction of other protein breakdown products, for the decreased acute-phase response observed in these patients. Our findings suggest that low-protein diets, and vegan in particular, may exert a beneficial effect on the development of cardiovascular disease in patients with end-stage renal disease (ESRD).

Nodular macroglossia with combined light chain and beta-2 microglobulin deposition in a long-term dialysis patient

We describe a case in which nodular macroglossia, a very rare type of tongue involvement, was associated with the co-deposition of lambda light chain and beta-2 microglobulin fibrils in the tongue. The combined presence of two different amyloid fibrils did not lead to a more unfavourable clinical outcome. We believe that both these features often remain underdiagnosed and are in fact more frequent than reported. A careful clinical examination of the tongue together with serum immunofixation should be routine in all patients with dialysis-related amyloidosis in order to investigate the prevalence and type of tongue involvement and to rule out other types of amyloidosis. In all cases of suspected mixed amyloidosis, immunohistochemical characterization of fibrils should be carried out by electron microscopy.

Autoantibodies against oxidized LDL in chronic renal failure: role of renal function, diet, and lipids

Lipid peroxidation (LP) has recently been suggested to trigger the atherosclerotic process as well as to worsen the progression of renal disease. Autoantibodies against oxidized low-density lipoproteins (Ox-LDLAb) were considered to provide a sensitive marker to detect LDL oxidation in vivo. To date few studies have been reported on Ox-LDLAb levels in patients with different degrees of renal failure. The aim of this study was to evaluate the influences of renal function, dietary manipulation, and lipids on Ox-LDLAb concentrations in uremic patients either on conservative or replacement therapy. Seventy-one patients (42 males, 29 females) aged 60 +/- 19 years with chronic renal failure (CRF) of different etiology and degree were divided into four groups according to serum creatinine levels [sCr(mg/dl)] and diet: CRF I > or = 1.5-3.0, CRF II > 3.0-5.5, and CRF III > 5.5 were all patients on a conventional low-protein diet, while a fourth group included patients on a vegetarian diet supplemented with keto analogues and amino acids (CRF SD >3.0). A further group was represented by patients on dialysis therapy. All patients were examined for Ox-LDLAb, triglycerides (TG), total cholesterol, HDL and LDL cholesterol, and apolipoproteins Apo A1, Apo B, and Lp(a). The results were compared with those of 20 controls (9 males and 11 females) aged 52 +/- 11 years with sCr <1.5 mg/dl. Ox-LDLAb increased, although not significantly, with TG and Lp(a) from the early stages of CRF along with the deterioration of renal function. However, TG and Lp(a) levels were significantly higher in all groups of patients except those on vegetarian diet (CRF SD). This group also showed the lowest Ox-LDLAb levels. No relationship was observed between lipids or apolipoproteins and Ox-LDLAb. Hyperlipidemic patients did not show higher Ox-LDLAb levels than normolipidemics. Our results show a progressive increase of LP as the renal function declines, which may account for the increased risk of cardiovascular disease reported in uremia. Dialysis does not correct significantly the oxidative state observed in patients with end-stage renal disease. Vegan diet, by reducing LP, TG, and Lp(a), is supposed to decrease the risk of cardiovascular disease and worth being reconsidered as an alternative effective therapeutic tool in patients with advanced CRF.

Total antioxidant capacity (TAC): is it an effective method to evaluate the oxidative stress in uraemia?

Lipoprotein abnormalities are common in uraemia and are considered important factors for development of atherosclerosis and progression of renal disease. Reduction of total antioxidant capacity (TAC) and lipid peroxidation (LP) probably play a major role in both processes. The aim of this study was to assess the effect of renal function, dietary manipulation and lipids on TAC of uraemic patients with different chronic renal failure (CRF). Sixty patients (36M, 24F), aged 60 +/- 12 years were divided into five groups according to serum creatinine levels (sCr,mg/dl)--CRFI, 1.5-3; CRFII, > 3-5.5; CRFIII, > 5.5; CRFIV, > 3 on vegetarian supplemented diet (SD); CRFV haemodialysis patients (HD)- and investigated for TAC by enhanced chemiluminescent assay, autoantibodies against oxidized LDL (oxLDLAb), lipids, apolipoprotein AI, B, Lp(a) and uric acid (UA). The results were compared to a control group of 19 people (8M, 11F), aged 52 +/- 11 years with sCr < 1.5. TAC increased significantly with the progression of CRF and was strongly related to both sCr and UA. Lipids and SD did not show any influence on TAC. Unexpectedly, lipid peroxidation did not correlate to TAC, neither to sCr or UA. HD accounted for a mild reduction of both TAC and LP. Patients on SD showed a marked reduction of LP as compared to patients with a similar degree of renal failure (CRF-III) but on conventional diet. Our results suggest that elevated TAC in uraemia is likely to be dependent on increased UA levels and does not seem to induce an effective protection in vivo from oxidative stress. In conclusion, TAC does not appear to be a reliable method for assessing the oxidative susceptibility of CRF patients.

Lp(a) levels: effects of progressive chronic renal failure and dietary manipulation

Patients with chronic renal failure (CRF) have an increased risk of cardiovascular disease (CVD). Elevated lipoprotein(a) (LP(a)) levels have been shown to be an important risk factor for CVD. This study examined Lp(a) changes during the progression of renal disease in patients following different dietary regimens. Fifty-seven patients with CRF of different etiology and degree (mean age 58 +/- 10 yrs) were divided into four groups according to their serum creatinine (sCr) levels. The first group had sCr 1.5-3; the second 3-6; the third > 6, all on a conventional low-protein diet (CLPD), and the fourth had sCr > 6 on a supplemented vegetarian diet (SVD). Lp(a), apoproteins AI, B, E, CII, CIII, CII/CIII, Apo A/Apo B ratios and the lipid pattern (total cholesterol (TC) and its fractions LDL, HDL, HDL3 and triglycerides) were investigated. Patients with diabetes, proteinuria > 1.5 g/24 h, hepatic disease or taking contraceptives or lipid lowering drugs were excluded. Results were compared with a reference group (N = 12) with sCcr < 1. Lp(a) concentrations increased with the progression of renal failure, and a significant correlation was observed with sCr. Despite the elevated sCr levels, patients on the SVD had an almost normal Lp(a) concentration. Only 15% of the reference group had Lp(a) levels > 30 mg/dl, compared to 33%, 50% and 78% of the 1st, 2nd and 3rd groups and 38% of the 4th group. No relationship was found between Lp(a), lipids or apoproteins. Our results indicate that renal function influences Lp(a) levels and suggest a SVD helps to lower them. This might be ascribed to some antioxidant factors in the SVD.

Familial AL-amyloidosis in three Italian siblings

BACKGROUND AND METHODS

Familial occurrence of immunoglobulin-related (AL) amyloidosis has occasionally been reported. In this work we describe the concomitance of systemic amyloidosis and monoclonal gammopathy (one case of Waldenström's macroglobulinemia and two cases without multiple myeloma or related diseases) in three Italian siblings, two males and one female.

RESULTS AND CONCLUSIONS

All of them showed a common pattern of polyneuropathy to different degrees; two presented a sicca syndrome and one also suffered from nephropathy. Two of them showed the same HLA typing with the same light chain type (k), but had different presenting symptoms. Polyneuropathy and a history of peptic disease in two cases was suggestive of type III familial amyloidotic polyneuropathy (FAP) occurring in the setting of a familial monoclonal component. However, immunohistochemical studies on different tissue specimens using anti-apolipoprotein A1 and anti-transthyretin antibodies were negative. Further screening of DNA samples for transthyretin (TTR) gene mutations was also negative. Clinical and laboratory investigations ruled out reactive or senile amyloidosis and immunohistochemical studies with anti-light chain antibodies on amyloidotic tissue specimens were positive. As a consequence, this family represents a new case of familial AL-amyloidosis.

Lipoprotein abnormalities in chronic renal failure and dialysis patients

Lipoprotein abnormalities are common in patients with chronic renal failure (CRF) on either dialysis or conservative therapy. In order to investigate the changes in lipid and apolipoprotein pattern from early CRF to dialysis treatment, plasma lipids with apoproteins AI, B, E, CII, CIII, CII/CIII ratio, E/CIII ratio, parathyroid hormone (PTH) and insulin levels were examined in 72 patients with different degrees of CRF and 31 patients on hemodialysis (HD), and compared the values of 28 controls. A significant decrease in the Apo CII/CIII ratio was the earliest lipoprotein abnormality to occur in CRF. Hypertriglyceridemia (HTG) with reduced high-density lipoprotein cholesterol levels, increased Apo CIII and decreased Apo E/Apo CIII ratio only occurred in more advanced renal failure (creatinine clearance < 31 ml/min). HD patients showed a general worsening of the lipoprotein profile with elevated Apo E levels and indirect evidence of remnant accumulation. While PTH did not have any significant influence on lipoprotein pattern, increased insulin levels during HD might partly account for the HTG of these patients. Our results point to elevated Apo CIII, reduced Apo CII/Apo CIII and Apo E/ Apo CIII ratios as typical features of uremic hyperlipidemia and show that a defective triglyceride removal is the major pathogenetic mechanism of uremic HTG. HD treatment seems generally to worsen the lipid and apolipoprotein pattern observed in the predialytic stage of CRF.

AL-amyloidosis in monoclonal gammopathies

Sixty-two patients affected by MGUS underwent fat tissue aspirate examination for diagnosis of AL amyloidosis. Nine out of the 62 were found to be Congo red positive. MGUS had already been diagnosed for quite a long time in about 60% of these patients, while this prevalence decreased to 24% among the Congo red negative patients. The follow-up of the positive patients is reported.

Lipids and apolipoproteins change during the progression of chronic renal failure

Uremic hyperlipidemia was recently suggested to contribute to progression of chronic renal failure (CRF). To investigate the relationship between lipoprotein abnormalities and decline of renal function, plasma lipids with apoproteins A1, B, E, CII, CIII, CII/CIII and E/CIII ratios, parathyroid hormone (PTH), insulin and glucose levels were examined in 72 patients with different degrees of CRF and compared to 28 patients of a reference group. A significant decrease of CII/CIII ratio was already evident below a Ccr of 60 ml/min, while increased apo-CIII and triglycerides (TG) with reduced HDL-cholesterol (HDL-C) levels occurred below a Ccr of 30 ml/min. Both TG and apo-CIII showed a positive correlation with creatinine levels. On the contrary, apo-CII/apo-CIII and HDL-C inversely correlated with the progression of renal failure. PTH and insulin showed a positive correlation with TG, the former being also inversely related to apo-CII/apo-CIII ratio. Our results point to early apolipoprotein changes in the course of CRF. Elevated apo-CIII and reduced apo-CII/apo-CIII ratio may be considered the most typical features of uremic hyperlipidemia and likely account for the impaired TG removal and the hypertriglyceridemia (HTG). Secondary hyperparathyroidism may contribute to reduce peripheral lipolytic activity and cause HTG. A contributory role of hyperlipidemia in the progression of renal disease is also supported.

Are lipid abnormalities reliable cardiovascular risk factors in dialysis patients?

Patients on chronic hemodialysis often present both hyperlipidemia and a high incidence of cardiovascular disease (CVD). Uremic hyperlipidemia has usually been regarded as one of the most important cardiovascular risk factors (CVRF) in these patients. In order to study whether the "uremia-induced" lipid abnormalities are actually associated with evidence of uremic CVD, and consequently may be considered reliable CVRF, 123 patients on chronic dialysis were reviewed for the presence of CVD and, at the same time, examined for their lipoprotein pattern and other clinical and biochemical variables. Lipids and lipoproteins did not prove helpful in our study in identifying patients with CVD. Despite the fact that they had been on dialysis for a shorter time, CVD patients were significantly older and had higher blood pressure than patients without CVD. Our data suggest that the uremia-induced lipid abnormalities are not reliable markers of CVD in dialysis patients, and support the hypothesis that dialysis per se does not accelerate the atherosclerotic process in uremic patients.

Aspects of biocompatibility of two different dialysis membranes: cuprophane and polysulfone

Intradialytic hypoxemia, leukopenia and coagulation system activation were monitored in 9 uremic patients during hemodialysis with cuprophane (Cu) and polysulfone (Psf) membranes, using the following parameters: polymorphonuclear count (PMN), elastase alpha-1 proteinase inhibitor (EI-alpha 1PI) complex, platelet count, beta-thromboglobulin (BTG), fibronectin (FN) and arterial oxygen tension (PaO2). Our results indicate that 1) intradialytic hypoxemia observed with both membranes does not seem to be exclusively related to the well-known membrane-dependent leukopenia; 2) platelet activation, as demonstrated by the plasma BTG increase, appears to be an exclusive cellulosic membrane-related phenomenon; 3) at the same time platelet activation seems to be the major factor responsible for high FN levels, the highest FN levels occurring concurrently with the lowest platelet count.

Renal involvement in IgD myeloma

Nine patients affected from IgD myeloma were studied retrospectively in order to elucidate the incidence and peculiar traits of related nephropathy. Eight patients developed chronic renal failure, and as many as 5 were already suffering from renal failure since first admission to the hospital. In 3 cases acute renal failure was the major presenting symptom of the disease. Five patients underwent a regular dialytic treatment. We suggest that the high incidence of renal involvement found in IgD myeloma is related to the high incidence of Bence-Jones proteinuria observed in this disease. Presenting atypical symptoms, among which renal failure is the most important, are misleading and characteristic of the disease. Survival time seems to be negatively influenced by the presence of renal failure at the time of diagnosis.

Leukocytes, eosinophils and complement function during hemodialysis with polysulphone and polymethylmethacrylate membranes: comparison with cuprophan and polyacrylonitrile

The biocompatibility of the two new dialysis membranes, polysulphone (PS) and polymethylmethacrylate (PMMA), was evaluated versus cuprophan (CUP) and polyacrylonitrile (PAN) by studying the in vivo effects of the four different membranes on leukocyte counts, eosinophil levels and complement function both in the presence and absence of dialysis fluid. Complement function was also examined in vitro by studying the generation of chemotactic factors, whole complement activity and C3d serum conversion. Passive absorption of complement fractions by membranes has completed in vitro studies. PS, PMMA and PAN showed a higher biocompatibility than CUP, even if slight differences can be observed: PS showed a PAN-like biocompatibility pattern with a relatively high absorption of complement factors by the membrane and without complement activation. On the other hand, PMMA showed a CUP-like pattern and caused complement activation, even though to a lower intensity than CUP. PMMA biocompatibility appears to stand in-between CUP and the other two synthetic membranes PS and PAN. Our results confirm the important role played by membrane-induced complement activation on hemodialysis leukopenia. Dialysis fluid does not have a significant influence on membrane biocompatibility, but represents the major factor in determining intradialytic eosinopenia. Eosinophils seem to represent a more important marker of dialysis than of membrane biocompatibility.

In vitro interleukin-1 production by different dialysis membranes

This study investigates the Il-1 production in vitro by normal peripheral blood monocytes or non-T cells following contact with different dialysis membranes (cuprophan, polysulphone, polymethylmethacrylate and polyacrylonitrile), in the presence or absence of lipopolysaccharide. The results of this study show that the physical contact between dialysis membranes and Il-1 producing cells is not by itself able to induce abundant Il-1 production unless exogenous lipopolysaccharide is added. A modest Il-1 production, however, could be observed with synthetic membranes (polysulphone and polyacrylonitrile), but not with cellulose membranes (cuprophan). Used membranes are completely ineffective as a trigger of Il-1 synthesis.