Z. Galazka

Vascular Access for Haemodialysis in Patients with Central Vein Thrombosis

OBJECTIVES Dialysis-dependent patients often have central venous drainage complications. In patients with functioning arm arteriovenous fistula, this may result in venous hypertension, arm oedema and vascular access failure. Percutaneous angioplasty and stent implantation might be inadequate to resolve these issues. In these cases, new access can potentially be created with anastomosis to the subclavian vein, iliac vein or vena cava or by making a veno-venous graft to bypass the thrombosis. The aim of this study was to assess the utility of unusual bypasses in vascular access in patients with the central vein thrombosis. MATERIALS A total of 49 patients were treated. The mean number of previous vascular access surgery procedures was 7.6 (3-17). We performed 19 axillo-iliac, 14 axillo-axillary bypasses and 16 conduits from the arm fistula to the jugular (nine conduits) or subclavian (seven conduits) vein for haemodialysis purposes. RESULTS All fistulas except one were used for haemodialysis. One patient died before the first use of the fistula. At 12 months, the primary, primary assisted and secondary patency rates were 85.4%, 89.6% and 95.8%, respectively. The follow-up period ranged from 1 to 84 months. CONCLUSION Unusual grafts are an efficient option as a permanent vascular access for haemodialysis purposes in patients with central vein occlusion.

Human herpesvirus-6 in renal transplant recipients: Potential risk factors for the development of human herpesvirus-6 seroconversion

Herpesviruses, including human herpesvirus-6 (HHV-6), reactivate and have the potential to be pathogenic in immunocompromised patients. Little information is available regarding the correlation between immunosuppressive therapy and HHV-6 seroconversion after organ transplantation. Serum samples obtained from 120 kidney and kidney/pancreas transplant recipients were tested to explore the potential risk factors for developing HHV-6 infection including types of immunosuppression and induction/rejection therapy. Stored serum samples obtained prior to and at the 2nd, 4th, 12th and 48th weeks after transplantation were tested for anti-HHV-6 immunoglobulin (Ig)M antibodies using indirect immunofluorescence assay. Prior to transplantation and 48 weeks after transplantation the sera were additionally tested for anti-HHV-6 IgG using enzyme-linked immunoassay. Ninety-one percent of 120 recipients were HHV-6 IgG-positive before transplantation. One hundred seven of 120 patients were anti-HHV-6 IgM-negative before transplantation. Primary/secondary HHV-6 seroconversion occurred in sera of 46.6% of these 107 patients. HHV-6 seroconversion most frequently occurred 2 to 4 weeks after transplantation. There was no significant relationship between HHV-6 seroconversion and the treatment with methylprednisolone (MP). The incidence of HHV-6 seroconversion was significantly higher in subjects who were treated with the regimens including Daclizumab or Sirolimus as compared with those who were on other protocols. HHV-6 seropositivity in the Polish population of organ transplant recipients is very high. We demonstrated a trend toward association of HHV-6 seroconversion with type of immunosuppressive therapy.

Is Severe Atherosclerosis in the Aortoiliac Region a Contraindication for Kidney Transplantation

BACKGROUND Atherosclerosis is common in end-stage renal disease patients on dialysis. However, it has previously been considered to be a relative contraindication to kidney transplantation. Currently, patients with extended indications are accepted onto the waiting list, including those with severe atherosclerosis. These patients require vascular procedures before or during kidney transplantation. The aim of this study was to present our experience with vascular reconstruction before kidney transplantation. MATERIAL AND METHODS Twelve atherosclerotic, uremic patients referred to be candidates for kidney transplantation were refused because of occlusive lesions of the iliac arteries or the distal aorta. The 10 males and 2 females had an age range of 45 to 68 years. Preoperative assessments consisted of a Doppler ultrasound and an angio computed tomography scan. The reconstructions were performed with aorto-biliac, aorto-bifemoral, or ilio-femoral dacron grafts in 7, 4, and 1 patient, respectively, under general anesthesia. RESULTS There were no major postoperative complications; the patients were discharged and placed on a special waiting list. Eight patients received kidney allografts, including one living-related transplantation. All procedures were performed with arterial anastomosis of the transplanted kidney to the side of the prosthesis. No patient developed signs of arterial graft infection. In the postoperative period, there were no arterial or transplanted kidney-related complications, except for delayed graft function in four cases. The remaining four patients are still on the waiting list. CONCLUSION In end-stage renal disease patients with severe atherosclerosis in the aortoiliac region, vascular reconstruction allows kidney transplantation.

Transplant glomerulopathy: clinical and pathological correlations.

OBJECTIVE Chronic transplant glomerulopathy (TG) is one of the leading causes of severe posttransplantation proteinuria and graft loss. Our current knowledge about risk factors for the development of TG, as well as factors that affect its dynamics and prognosis, is poor. We sought to describe the pathological and clinical risk factors and correlations of TG as well as parameters that influenced the survival of grafts with that pathology. MATERIALS AND METHODS We retrospectively reevaluated 86 kidney transplant cases with TG that have been recognized on the basis of an indication biopsy since 1997. All TG as well as all pre-TG (previous) biopsies were characterized for the presence of C4d deposits in the graft. RESULTS Younger recipient age and minimal immunosuppression due to drug withdrawal or suboptimal drug doses/blood levels within 3 to 6 months preceding the biopsy were associated with C4d deposition in peritubular capillaries (PTC; P = .0053 and P = .0365, respectively). Diffuse PTC-itis (P = .029, RR [95% confidence interval] = 3.349 [1.131-9.919]) and total interstitial inflammation score (P = .015, RR [95% confidence interval] = 9.662 [1.784-52.329]) were observed to show a negative impact on graft survival. C4d deposition in PTC and glomeruli, the level of pretransplantation sensitization, episodes of acute rejection, and C4d in previous (pre-TG) biopsies did not influence the survival of grafts with TG. CONCLUSIONS Younger recipient age and minimal immunosuppression were associated with C4d positivity in grafts with TG. The survival of kidney grafts with TG was significantly affected by the magnitude of inflammation in the interstitium and PTC, but not by C4d positivity in PTC and glomeruli.

The role of the protocol biopsies in renal allograft recipients

Subclinical rejection and long-term cyclosporine nephrotoxicity are well-known risk factors of chronic allograft nephropathy. In a prospective study 32 low-risk patients were randomized to either a reduced CsA dose (5 mg/kg/d) and daclizumab (group A, n = 16) for 7 months posttransplant with subsequent CsA tapering/withdrawal, or to a normal CsA dose (10 mg/kg/day) without daclizumab (group B, n = 16). Both groups received MMF and prednisone. Protocol biopsies were obtained at engraftment and 3 and 12 months after Tx. The number of rejection episodes was the primary endpoint. The secondary endpoints were: renal function, histological parameters related to CsA, and serum levels of TGF-beta and PDGF-BB. A low incidence of clinically suspected rejection episodes was observed (19% in group A and 12.4% in group B; P = NS). Although protocol biopsies showed 12 subclinical rejection episodes (six in group A, six in group B), serum creatinine levels were not different between the examined groups at 3 months. However, at 12 months, there was a statistically improved mean creatinine level in group A patients (1.2 mg/dL +/- 0.5 in group A vs 1.54 mg/dL in group B; P <.05). Chronic histopathologic changes were significant for biopsies at 3 and 12 months in both groups compared to the baseline findings for protocol biopsies (with no differences between groups, or between 3 and 12 months in both groups). Serum TGF-beta and PDGF-BB did not differ between the groups. Protocol biopsies may be useful to monitor safety and efficiency of new immunosuppressive protocols. Immunosuppressive regimens with low CsA doses followed by the drugs complete withdrawal seem to be efficient and safe in low-risk kidney allograft recipients.

Do high levels of serum triglycerides in pancreas graft recipients before transplantation promote graft pancreatitis

OBJECTIVE Graft pancreatitis is a serious complication following pancreas transplantation. The aim of this study was to evaluate the influence of pretransplant serum lipid levels on the development of graft pancreatitis among patients undergoing simultaneous pancreas and kidney transplantation (spkTx). METHODS We reviewed data from spkTx patients engrafted between 1999 and 2002. Group 1 consisted of 10 recipients with well-established pancreas and kidney graft function without postoperative pancreatitis; group 2 5 spkTx recipients who developed fatal graft pancreatitis in the first posttransplant month. The lipid parameters evaluated within 1 hour before transplantation and after hemodialysis included total cholesterol, HDL, LDL, VLDL, triglicerides and apoproteins A and B. RESULTS Triglycerides, apoprotein B and VLDL were significantly increased just before transplantation among patients who developed fatal pancreatitis compared to those patients with good graft function. CONCLUSION Recipient hypertriglyceridemia promotes graft pancreatitis in previously injured pancreatic graft.

Tolerance of Enteric-Coated Mycophenolate Sodium in Combination With Calcineurin Inhibitor in Kidney Transplant Recipients: Polish Experience

INTRODUCTION Enteric-coated mycophenolate sodium (EC-MPS) was developed to reduce the incidence of gastrointestinal adverse effects. This multicenter observational study was designed to evaluate the safety profile and drug tolerance in kidney transplant recipients. METHODS Three hundred adult kidney recipients (median age 48 years) were enrolled over 3 years to receive EC-MPS de novo (n=175), as a switch from azathioprine (n=62) or mycophenolate mofetil MMF (n=63); in combination with calcineurin inhibitor. Drug doses, serum creatinine, estimated glomerular filtration rate (eGFR), as well as drug tolerance, patient and physician evaluation of therapy (on a 4-point scale) were recorded at enrollment and followed over 28 weeks. We modeled the probability of the highest level (ie, best result) of the categorical outcome variable. RESULTS Two hundred seventy-three patients completed the study (91%). In the pooled study group (1) best drug tolerance was expected more frequently with tacrolimus versus cyclosporine (odds ratio [OR] 2.12, P<.05); (2) best physician evaluation, with earlier EC-MPS introduction (OR for 4-week delay: 0.99, P<.03) and higher eGFR (OR for 5 mL/min increase: 1.21, P<.01). Among the EC-MPS de novo administrations group: (1) best drug tolerance was expected more frequently with coadministered tacrolimus versus cyclosporine (OR 3.14, P<.02); (2) best patient evaluation, with higher eGFR (OR for 1 mL/min increase: 1.04, P<.04); and (3) best physician evaluation, with higher eGFR (OR for 1 mL/min increase: 1.04, P<.001) and earlier EC-MPS introduction (OR for 4-week delay: 0.99, P<.03). In the conversion from MMF to EC-MPS group: (1) best drug tolerance was expected less frequently with coadministered cyclosporine versus tacrolimus (OR 0.05, P<.04) and more frequently with younger recipients (OR .001, P<.04); (2) best physician evaluation was expected more frequently with lower EC-MPS dose (OR for 360-mg dose increase: 0.4, P<.01) and with higher eGFR (OR for 5 mL/min increase: 1.42, P<.002). Adverse events were reported among 49/300 patients (16 serious adverse events). CONCLUSIONS EC-MPS was tolerated better by younger kidney recipients, when combined with tacrolimus versus cyclosporine, and when introduced earlier after transplantation. EC-MPS tolerance decreased gradually with renal function deterioration.