Eye Problems in Patients on the Active and Inactive Kidney Transplantation Waiting List

Renal transplant is the best form of treatment for most patients with end-stage renal disease. The aim of this study was to examine the prevalence of eye problems in patients with end-stage renal disease on the kidney transplantation waiting list in regard to their status (active vs temporarily disqualified). The cross-sectional study was conducted on 90 prevalent patients in 1 regional qualification center. There were 24 peritoneally dialyzed patients, 5 patients registered for preemptive transplantation, and 61 hemodialyzed patients. Average age of patients who had been registered on the cadaver kidney waiting list was 50 (± 14) years, with a balanced sex ratio and median dialysis duration of 38 months. The primary cause of end-stage renal failure was chronic glomerulonephritis in 42 cases, diabetic nephropathy in 10 cases, hypertensive nephropathy in 12 cases, autosomal dominant polycystic kidney disease in 7 cases, and other or unknown in the remaining patients. The major diagnosis was hypertensive angiopathy (related to the presence of long-term hypertension and history of kidney disease) in 56 patients, diabetic retinopathy in 8 patients, blindness in 4 cases (due to solvent intoxication in 1 case), and eyesight abnormalities (myopia, hyperopia, anisometropia) in 7 cases. Cataracts were described in 10 patients in addition to other findings. In 15 patients ophthalmology examination was normal, predominantly in younger patients. Abnormalities were more common in patients on the inactive list. In the vast majority of potential kidney transplant recipients, ophthalmology disturbances are primarily related to the underlying disease. The ophthalmology consult is part of the qualification, but the abnormalities are not the exclusion criteria.

Renal Artery Resistance Index, Thyroid Hormones, and Thyroid Volume in the Early Kidney Transplants Recipients

BACKGROUND

Thyroid hormones could affect renal function, and, on the other hand, renal dysfunction may affect thyroid function. Disturbances of concentrations of thyroid hormones are often associated with thyroid gland enlargement. The aim of the study was to assess the function and morphology of the thyroid (volume and hormones concentration) and kidney function after transplantation (creatinine concentration and resistance index [RI] of transplant artery).

MATERIAL AND METHODS

The group included 13 females, 19 males; aged 19-69 years, mean 44.75 +/- 14.8 years after transplantation with stable graft function. Thyroid volume, renal artery RI, creatinine concentration, and concentrations of T3, rT3, FT3, FT4, and TSH were estimated the day before surgery, and at 1, 3, 6, and 10 days after transplantation.

RESULTS

The statistical analysis revealed a negative correlation between delta RI (difference between RI at 3 and 6 days after transplantation) and serum creatinine concentration, 10 days after transplantation (r = -0.63; P < 0.01). We also observed a negative correlation between creatinine serum concentration at 10 days after transplantation and delta thyroid volume (Delta Vol; r = - 0.48; p < .05), a positive correlation between delta FT4 (Delta FT4) serum concentration, and delta creatinine (Delta Crea; r = 0.73; P < .001).

CONCLUSIONS

The dynamics of RI changes in the transplant kidney artery between 3 and 6 days after transplantation may predict graft function. Together with improved kidney function at 10 days after transplantation, we observed a regression of goiter.

Tartrate-resistant acid phosphatase 5b and its correlations with other markers of bone metabolism in kidney transplant recipients and dialyzed patients

PURPOSE

Renal osteodystrophy is a common complication of chronic renal failure and renal replacement therapy. Successful kidney transplantation reverses many of these abnormalities, however, the improvement is often incomplete. The osteoclast specific 5b isoform of tartrate-resistant acid phosphatase (TRAP) 5b has recently been proposed a specific and sensitive marker of bone resorption. The aim of the study was to assess correlations of TRAP 5b with markers of bone resorption and formation in kidney transplant recipients, hemodialyzed and peritoneally dialyzed patients and healthy volunteers.

MATERIAL AND METHODS

We assessed PTH, markers of bone formation-alkaline phosphatase and its bone isoform, osteocalcin, markers of bone resorption--procollagen type I carboxy-terminal extension peptide, procollagen type I cross-linked carboxy-terminal telopeptide, serum CrossLaps-Ctx, beta2-microglobulin and urinary deoxypyridynoline (DPD), expressed as DPD/creatinine ratio. (BMD) bone mineral density measurements were determined for femoral neck and lumbar spine (L2-L4) using DEXA.

RESULTS

In dialyzed patients markers of bone formation and resorption were significantly higher than in healthy volunteers, whereas in kidney transplant recipients these disturbances were less pronounced. TRAP 5b correlated positively with age and mainly with markers of bone resorption in kidney transplant recipients, dialyzed patients and healthy volunteers. TRAP 5b did not correlate with BMD in any groups studied.

CONCLUSION

Since TRAP 5b correlated mainly with markers of bone resorption, it may serve as a new additional marker of bone resorption in the assessment of renal osteodystrophy.

Thrombin activatable fibrinolysis inhibitor (TAFI) in stable angina pectoris patients undergoing coronary artery bypass grafting (CABG)

PURPOSE

Thrombin activatable fibrinolysis inhibitor (TAFI) seems to be a potential haemostatic risk factor of coronary artery disease (CAD). Taking into account interactions between TAFI and haemostasis, especially during cardiopulmonary bypass, we decided to determine concentration of TAFI and activated TAFI (TAFIa) and other haemostasis markers in CABG patients.

MATERIAL AND METHODS

45 CAD patients (11 women, 34 men) undergoing elective CABG were included in the study. Blood samples were taken before the operation, on the 3rd, 7th day and 3 months after CABG. A value of p<0.05 was considered statistically significant.

RESULTS

We found a significant decrease in TAFIa concentration on 3rd postoperative day: 6 microg/ml (0.3-43.2) vs 8.9 microg/ml (0.5-37) before CABG (p<0.05), a significant increase in TAFI concentration on the 7th postoperative day: 127.7% +/- 36.8 vs 112.18% +/- 30.34 of standard plasma concentration before CABG (p<0.05), significant increase in plasmin-antyplasmin (PAP) complexes concentration on 3rd and 7th day, respectively: 645 microg/l (323-1237) vs 406 microg/l (197-1840) before CABG (p<0.001); and 1030 microg/l (640-2149) vs 406 microg/l (197-1840) before CABG (p<0.0001). Before operation we found a significant negative correlation between PAP complexes concentration before CABG and EuroSCORE risk scale value (p<0.01).

CONCLUSIONS

In CABG patients, there is a significant increase in fibrinolytic activity due to decrease in TAFIa concentration, with simultaneous increase in PAP complexes. A significant negative correlation between PAP complexes concentration before CABG and EuroSCORE risk scale value stressed a potentially higher operation risk in patients with lower fibrinolytic activity.

Protein Z and vitamin K in kidney disease

PURPOSE

Disturbances in hemostasis are common complications of kidney diseases. Both bleeding diathesis and thromboembolism may complicate the course of chronic uremia. As far as we know, there is a limited data about protein Z in kidney disease.

MATERIAL AND METHODS

The aim of our work was to examine plasma protein Z and vitamin K concentrations in nephrotic syndrome (n = 34), glomerulonephritis (n = 48), kidney transplant recipients (n = 80), peritoneally dialyzed patients (n = 42) and in the healthy volunteers (n = 27).

RESULTS

Vitamin K was significantly lower in nephrotic syndrome when compared to non-nephrotic patients, CAPD and healthy volunteers (p < 0.05). Protein Z was the highest in CAPD and kidney transplant recipients when compared to any other group. In nephrotic syndrome protein Z was significantly lower when compared to the healthy volunteers, but it did not differ significantly between two groups of patients with chronic renal failure (with and without nephrotic syndrome). Protein Z correlated only with fibrinogen in CAPD, glomerulonephritis and nephrotic patients. Vitamin K correlated with age and albumin in patients with glomerulonephritis, nephrotic syndrome as well as with albumin in CAPD.

CONCLUSIONS

Alterations in protein Z might contribute to the enhanced risk of thromboembolic complications in nephrotic syndrome, CAPD and Tx via different and unknown mechanisms. This phenomenon seems to be unrelated to vitamin K status in these patients.

Correlations of new markers of bone formation and resorption in kidney transplant recipients

Renal osteodystrophy is a common complication of chronic renal failure and renal replacement therapy. Successful kidney transplantation reverses many of these abnormalities, but the improvement is often incomplete. The evaluation of renal osteodystrophy in everyday practice is based on noninvasive measurements. Taking this into consideration the aim of the present study was to assess new markers of bone metabolism: serum CrossLaps degradation products of C-terminal telopeptides of type I collagen tartrate-resistant acid phosphatase (TRAP) and bone-specific alkaline phosphatase (bALP), as well as their correlations with bone mineral disease (BMD) in kidney transplant recipients. Twenty-six patients (aged 26 to 54 years) receiving a triple immunosuppressive regimen with stable graft function were enrolled in the study. Serum parathormone (PTH) osteocalcin type collagen C-terminal peptides (ICTP), and procollagen type I carboxyterminal extension peptide (PICP) concentrations were measured by radioimmunoassay (RIA), Serum CrossLaps, bALP, beta2-microglobulin, TRAP 5b by enzyme-linked immunoassay (ELISA), and deoxypyridinoline (DPD) in urine immunochemiluminescence. BMD, as measured by dual-energy X-ray absorptiometry (DEXA), correlated negatively with markers of bone formation (bALP, osteoclacin, and PICP) and resorption (TRAP, ICTP, and beta2-microglobulin). The only positive correlation was between urine DPD and BMD at the femoral neck. Interestingly, BMD correlated negatively with CsA concentration. TRAP 5b correlated positively with serum creatinine, ALP, bALP, osteocalcin, iPTH, ICTP, and serum beta2-microglobulin, and negatively with CsA concentration, and azathioprine and prednisone dose. DPD did not correlate with any parameters. Serum CrossLaps correlated with markers of both bone formation and resorption. Because TRAP and serum CrossLaps correlated with markers of both bone formation and or resorption, additional studies are needed to establish the value of these markers of bone resorption to assess renal osteodystrophy.

Patients on peritoneal dialysis but not on hemodialysis have elevated concentration and activity of thrombin-activatable fibrinolysis inhibitor

Cardiovascular disease (CVD) is a leading cause of death in patients on dialysis. Increased concentration of fibrinogen, dyslipidemia and impaired fibrinolysis are regarded as important risk factors for CVD. Thrombin-activatable fibrinolysis inhibitor (TAFI) is a recently discovered inhibitor of the fibrinolytic system. The aim of this study was to investigate whether peritoneal dialysis (PD) and hemodialysis (HD) patients differ with regard to TAFI concentration and/or its activity. We also measured albumin, cholesterol, triglycerides and fibrinogen. The study was performed on 35 chronically dialyzed patients (14 on PD and 21 on HD) and 18 healthy volunteers. TAFI antigen and its activity were measured with commercially available kits. Albumin, cholesterol, triglycerides and fibrinogen were measured using standard laboratory methods. Only PD patients had significantly elevated level of TAFI antigen and its activity compared to control subjects. Differences in TAFI concentration and its activity between PD and HD were at the level of statistical significance (P=.09 and P=.07, respectively). PD patients had significantly higher concentration of cholesterol and triglycerides than HD group. Fibrinogen was elevated significantly in PD patients compared to HD and controls. There was no difference in albumin concentration between PD and HD. Significant positive correlations were found between fibrinogen or triglycerides and TAFI activity only in PD patients. We conclude that the above phenomenon may predispose PD patients to suppression of fibrinolysis.

Effects of long-term treatment with simvastatin on some hemostatic parameters in continuous ambulatory peritoneal dialysis patients

BACKGROUND/AIM

Disturbances in serum lipids, hemostasis and platelet functions are frequent features in uremia and may contribute to the progression of atherosclerosis and its thrombotic complications. Recently, attention has been paid to beneficial effects of statins on serum lipids and hemostasis in uremic patients. Peritoneally dialyzed (continuous ambulatory peritoneal dialysis; CAPD) subjects are particularly prone to dyslipidemia and have a high risk of cardiovascular death. The purpose of this work was to assess platelet functions, some hemostatic parameters and serum lipids in 8 hyperlipidemic CAPD patients treated with simvastatin (Zocor, MSD) for 6 months.

METHODS

Platelet aggregation in whole blood and in platelet-rich plasma (PRP) induced by collagen (2 microg/ml for whole blood and PRP), arachidonic acid (0.75 mM for whole blood and PRP), ADP (10 microM for whole blood and 5 microM for PRP) and ristocetin (0.75 mg/ml for whole blood and 1.5 mg/ml for PRP) was studied before and after 1, 3 and 6 months of simvastatin (dose: 10 mg at bedtime) treatment.

RESULTS

Whole-blood platelet aggregation induced by collagen decreased significantly after 3 and 6 months of the therapy, whereas in PRP, platelet aggregation induced by collagen and ADP decreased significantly after 6 months. Ristocetin-induced platelet aggregation in PRP decreased significantly after 3 and 6 months of simvastatin therapy. P-selectin remained unaltered by 6 months of simvastatin therapy. The fibrinolytic activity index was significantly higher after 3 months of the therapy when compared to the baseline values. Thrombomodulin, a marker of endothelial cell injury, was significantly lower after 3 and 6 months of the therapy. Prothrombin fragments 1 + 2 did not change significantly during 6 months of simvastatin administration. Cholesterol and LDL fell significantly as early as after 1 month and remained lowered during further months of the therapy.

CONCLUSION

Simvastatin is an effective hypolipemic agent and favorably affects platelet aggregation, endothelial function and fibrinolysis in CAPD patients.

[Platelet aggregation and P-selectin concentration in patients on peritoneal dialysis treated with erythropoietin]

In chronic renal failure disturbances of hemostasis are predominantly due to the defective platelet function and platelet/vessel wall interactions. Erythropoietin, used for treatment of renal anemia, affect hemostasis in dialyzed patients. The aim of the work was to assess platelet aggregation and P-selectin concentration in patients on continuous ambulatory peritoneal dialysis (CAPD) during erythropoietin therapy. The studied were performed on 12 CAPD patients, administered with subcutaneous erythropoietin in a dose of 2000 U three times a week for 3 months. Hemoglobin, hematocrit and erythrocyte count increased significantly after 1 month of the treatment. Platelet aggregation in platelet-rich plasma induced by collagen, ristocetin and serotonin increased significantly after 3 months of erythropoietin therapy when compared to the baseline values. Whole blood platelet aggregation and P-selectin concentration did not change significantly during 3 months of erythropoietin therapy. Erythropoietin treatment in CAPD patients did not affect significantly platelet aggregation and activation.

Leptin and serum erythropoietin in hemodialyzed and peritoneally dialyzed uremic patients during rHuEPO therapy

Leptin produced by fat cell has an unanticipated role in hematopoietic system development. We examined the relationships between leptinemia and requirements of erythropoietin (Epo), endogenous Epo levels as well as markers of inflammation: C-reactive protein, tumor necrosis factor alpha (TNFalpha) and interleukin-1 (IL-1) in rHuEPO-treated patients maintained on chronic hemodialyses or peritoneal dialyses. The studies were performed on 51 chronically hemodialyzed patients, 20 of them did not receive rHuEPO, 31 subjects received rHuEPO, and 22 patients on CAPD, 13 of them did not receive rHuEPO, 9 subjects were given rHuEPO. In hemodialyzed patients (Epo and Non-Epo group) leptin levels were significantly higher when compared to CAPD patients (Epo and Non-Epo group, respectively). Leptin in peritoneal fluid was significantly higher in the Non-Epo group. In ultrafiltrate, leptin levels were below the detection limit of 0.5 ng/ml. Epo levels in the HD + Epo group were significantly lower than in the HD + Non-Epo group and CAPD + Epo group. TNFalpha and IL-1 concentrations were significantly lower in both groups of CAPD patients when compared to respective HD groups. Treatment with rHuEPO resulted in nonsignificant decline in serum leptin (p = 0.07 in HD and p = 0.08 in CAPD) and significant leptin loss in peritoneal fluid. It may be of clinical relevance in dialyzed patients. In both groups of Epo-treated patients, positive physiological correlation between leptinemia and BMI disappeared. Leptin levels do not correlate with rHuEPO requirements and serum Epo in dialyzed patients.

Importance of serotonergic mechanisms in the thrombotic complications in hemodialyzed patients treated with erythropoietin

So far it is not clear how erythropoietin affects the anticoagulant properties of vascular endothelium in uremia. Since serotonin is also thought to play a role in the pathogenesis of thrombosis, the aim of the study was to evaluate major components of extrinsic coagulation pathway, markers of endothelial cell injury, lipoprotein (a) and peripheral serotonergic mechanisms during rHuEPO therapy in hemodialyzed patients. The study was performed on chronically hemodialyzed patients divided into two groups: with rHuEPO treatment and without rHuEPO therapy in relation to the control group. In uremic patients, thrombomodulin and von Willebrand factor, activity of factor VII, tissue factor pathway inhibitor (TFPI) activity, TFPI and tissue factor (TF) concentrations, lipoprotein (a) level were significantly higher when compared to healthy volunteers. Treatment with rHuEPO resulted in a further significant rise in markers of endothelial cell injury: thrombomodulin and von Willebrand factor and TFPI concentration. Extrinsic coagulation factors: activities of factor VII and X, TFPI activity and TF activity and concentration, lipoprotein (a) and vitronectin remained unchanged during rHuEPO therapy. Platelet serotonin content and whole blood serotonin were significantly lower in uremic patients relative to healthy volunteers and during rHuEPO treatment they increased significantly. Whole blood serotonin reached normal values. Plasma serotonin, significantly elevated in uremia, did not change during rHuEPO therapy. Serotonin uptake by uremic platelets was significantly impaired and remained unaltered during rHuEPO administration. Serotonin release by uremic platelets was also significantly depressed but a significant improvement was observed in rHuEPO-treated patients. Our data suggest that endothelial injury, TF pathway components and peripheral serotonergic system disturbances may predispose to thromboembolic complications and play a role in the pathogenesis of atherosclerosis in uremic patients, particularly treated with rHuEPO. Increase in TFPI may compensate the increase in TF in these patients.

[Tissue factor and inhibitor of the blood coagulation pathway in nephrotic syndrome]

Some parameters of extrinsic coagulation pathway, vitronectin and thrombomodulin were studied in 21 patients with nephrotic syndrome. Concentrations of tissue factor and tissue factor pathway inhibitor were found to be significantly elevated in patients with nephrotic syndrome when compared to control group. Activities of tissue factor and tissue factor pathway inhibitor as well as vitronectin did not differ significantly from the healthy volunteers. Activities of factor VII and X were significantly higher in nephrotic patients when compared to the control group. Thrombomodulin--a marker of endothelial cell injury was significantly higher in patients with nephrotic syndrome relative to controls.

Cyclosporine A affects serotonergic mechanisms in uremic rats

The aim of this study was to investigate the mechanism of cyclosporine-induced hypertension in respect to its action on blood serotonergic system. The experiment was carried out on healthy rats and animals with experimental chronic renal failure. Cyclosporine A (CsA) injected into the healthy and uremic rats caused an increase in systolic blood pressure. This effect was completely abolished by ketanserin, an antagonist of 5-HT2 receptors. Concomitantly a rise in blood and platelet serotonin concentration was observed. It is concluded that serotonin may play a role in the development of hypertension caused by CsA. Moreover, ketanserin may serve as a drug for pharmacological protection of CsA-induced rise of blood pressure in uremia.

Effects of endothelin-1 on aggregation of normal and uremic platelets

Platelet aggregation was studied in the whole blood and platelet rich plasma (PRP) upon stimulation with various agonists (collagen- 0.5 microgram/ml in the whole blood and PRP, ADP 10 microM in the whole blood and 2 microM in PRP, ristocetin 0.75 mg/ml in the whole blood and 1.25 mg/ml in PRP and arachidonic acid (AA) 0.5 mM in the whole blood and PRP) following incubation with ET-1 at final concentrations of 0.1 microM and 0.2 microM for 1 and 5 min. Collagen- and ADP-induced platelet aggregation in PRP was found to be diminished following incubation with ET-1 for 1 and 5 min at the concentrations of 0.1 microM and 0.2 microM. Aggregation of platelets upon stimulation with AA and ristocetin remained unaltered following incubation with ET-1. In the whole blood ristocetin-induced platelet aggregation was significantly diminished following incubation with ET-1 for 5 min, whereas AA-induced platelet aggregation was not significantly changed following preincubation with ET-1. Our results suggest that platelets may possess ET-1 receptor(s) and that ET-1 may also interact with other blood cells.

Comprehensive study on platelet function, hemostasis, fibrinolysis, peripheral serotonergic system and serum lipids in nephrotic syndrome

A comprehensive study on platelet aggregation, hemostasis, fibrinolysis and serum lipids in relation to peripheral serotonergic system has been performed on 41 nephrotic patients. Enhanced platelet aggregatory responses in both whole blood and in platelet rich plasma (PRP) were found upon stimulation with different agonists when compared to healthy volunteers. Increased levels of fibrinogen, fibrin monomers, and protein C activity were observed in nephrotic patients. Euglobulin clot lysis time was significantly prolonged in nephrotic patients. Activity of tissue plasminogen activator (tPA) inhibitor was higher in nephrotic syndrome, whereas tPA activity was significantly lower in these patients when compared to controls. Urokinase concentration, lipoprotein (a), cholesterol, LDL and VLDL levels were significantly higher in nephrotic patients over controls. Whole blood serotonin was significantly lower, whereas plasma serotonin was significantly higher in nephrotic patients relative to controls. Serotonin uptake and its release from platelets were markedly diminished in patients with nephrotic syndrome. Disequilibrium in the coagulolytic system, platelet hyperactivity, hyperfibrinogenemia, disturbances in peripheral serotonergic system together with lipid abnormalities may contribute to the progression and development of atherosclerosis and an enhanced risk of thromboembolic complications in nephrotic syndrome.

[Fibrinolytic and lipid disturbances in patients with nephrotic syndrome]

Some fibrinolytic parameters (euglobulin clot lysis time, activities and antigens of tissue plasminogen activator and inhibitor), serum lipids and their mutual relations were studied in 31 patients with nephrotic syndrome. Euglobulin clot lysis time was found to be significantly prolonged in patients with nephrotic syndrome when compared to control group. Activity and antigen of tissue plasminogen activator were significantly higher in healthy volunteers, whereas nephrotic patients activity of tissue plasminogen activator inhibitor was significantly higher than in controls. Cholesterol, LDL and VLDL were elevated in patients with nephrotic syndrome when compared to controls. LDL was found to be positively related to both tissue plasminogen activity and antigen in nephrotic patients. Serum cholesterol correlated positively with albuminemia in these patients.