The impact of peritransplant warfarin use on renal transplant outcome

BACKGROUND

The unplanned nature of kidney transplantation necessitates that patients undergo surgery without prior cessation of warfarin. Our study analyses the impact of warfarin treatment in the peritransplant period on graft outcome and perioperative transfusion requirements.

METHODS

We identified 31 patients undergoing deceased donor kidney transplantation who were concurrently receiving warfarin therapy, between 2000 and 2008. A random, sex-matched, adult, deceased donor control group of 62 patients was generated from the Irish transplant database.

RESULTS

The warfarin group were older (mean 47.5 vs. 42.5 years, p=0.067) and had spent longer on dialysis prior to transplantation (mean 3.5 vs. 2.1 years, p=0.004). Graft survival in the warfarin group was not significantly different at 1-, 3- and 5-year follow-ups. There was no statistically significant difference in red blood cell transfusions between the groups (45% vs. 29%, p=0.2). Warfarin patients had a prolonged mean cold ischaemia time (22.3 vs. 18.5 hours, p=0.002).

CONCLUSION

This study demonstrates excellent short- and long-term results for kidney transplantation in patients requiring warfarin at the time of transplantation.

Encapsulating peritoneal sclerosis: experience of a tertiary referral center

AIM

Encapsulating peritoneal sclerosis (EPS) is arguably the most serious complication of chronic peritoneal dialysis (PD) therapy with extremely high mortality rates. We aimed to establish the rates of EPS and factors associated with its development in a single center.

METHODS

We retrospectively reviewed the records of all our PD patients from 1 January 1989 until 31 December 2008. All suspected cases were confirmed at laparotomy. Multifactorial models adjusted for potentially confounding variables such as age and sex.

RESULTS

Eleven cases of EPS were identified giving a prevalence rate of 1.98%. Median duration on PD was substantially longer in affected versus unaffected patients (42.5 months versus 13.8 months; p = 0.0002). EPS patients had experienced a mean of 3.54 previous cases of peritonitis (1 infection per year versus 0.71 per year in unaffected patients; p = 0.075). Six patients died (54.5%) due to intra-abdominal sepsis including all five who presented with small bowel obstruction. Three patients had an omentectomy and adhesiolysis performed with a successful outcome.

CONCLUSION

Our study reinforces the link between duration on PD and EPS. While mortality was high in our cohort, emerging surgical techniques demonstrate a favorable outcome that can be achieved even in severely affected cases.

Nephrogenic systemic fibrosis

Nephroaenic systemic fibrosis (NSF) is a potentiallv fatal dermatiological condition found exclusively in patients with advanced renal I failure. There is minimal literature regarding the epidemiology and outcomes of patients with NSF in Ireland. A retrospective chart review was performed for all patients with NSF in Ireland. Ireland's experience with the disease was examined in light of international reports. There have been three cases of NSF in Ireland; an area which serves 1915 dialysis patients--giving a point prevalence among Irish end-stage kidney disease patients of 0.002. There was a large variation in disease severity between the three patients. All three patients had significant exposure to gadolinium chelate. Caution with gadolinium administration must be exercised in patients with advanced renal failure.

EBV-positive B cell cerebral lymphoma 12 years after sex-mismatched kidney transplantation: post-transplant lymphoproliferative disorder or donor-derived lymphoma?

We present a follow-up case report of possible transmission of lymphoma 12 years after deceased-donor renal transplantation from a male donor who was found at autopsy to have had an occult lymphoma. The female recipient underwent prompt transplant nephrectomy. However, 12 years later, she presented with cerebral B cell lymphoma. A donor origin for the cerebral lymphoma was supported by in situ hybridization demonstration of a Y chromosome in the lymphoma. There was a dramatic resolution of the cerebral lesions with tapering of immunosuppression and introduction of rituximab treatment. The finding of a Y chromosome in the cerebral lymphoma does not exclude a host contribution to lymphoma development.

Higher tacrolimus trough levels on days 2-5 post-renal transplant are associated with reduced rates of acute rejection

We analyzed the association between whole-blood trough tacrolimus (TAC) levels in the first days post-kidney transplant and acute cellular rejection (ACR) rates. Four hundred and sixty-four consecutive, deceased-donor kidney transplant recipients were included. All were treated with a combination of TAC, mycophenolate mofetil and prednisolone. Patients were analyzed in four groups based on quartiles of the mean TAC on days 2 and 5 post-transplant: Group 1: median TAC 11 ng/mL (n = 122, range 2-13.5 ng/mL), Group 2: median 17 ng/mL (n = 123, range 14-20 ng/mL), Group 3: median 24 ng/mL (n = 108, range 20.5-27 ng/mL) and Group 4: median 33.5 ng/mL (n = 116, range 27.5-77.5 ng/mL). A graded reduction in the rates of ACR was observed for each incremental days 2-5 TAC. The one-yr ACR rate was 24.03% (95% CI 17.26-32.88), 22.20% (95% CI 15.78-30.70), 13.41% (95% CI 8.15-21.63) and 8.69% (95% CI 4.77-15.55) for Groups 1-4, respectively (p = 0.003). This study suggests that higher early TACs are associated with reduced rates of ACR at one yr.

An unusual case of cancer of the urachal remnant following repair of bladder exstrophy

INTRODUCTION

We report the first case of cancer of the urachal remnant following repair of bladder exstrophy, in a renal transplant recipient.

METHOD

A retrospective review of this clinical case and the associated literature were performed.

CONCLUSION

This unusual case highlights two very rare entities. Bladder exstrophy has an incidence of 1 in 50,000 newborns, whereas urachal cancer accounts for less than 1% of all bladder tumours.

Effect of cytomegalovirus prophylaxis with acyclovir on renal transplant survival

It is recognized that cytomegalovirus (CMV) infection in transplant recipients may lead to graft loss. Prophylaxis with acyclovir has therefore gained widespread acceptance, but the debate on whether this intervention improves long term graft survival continues. All patients who received renal grafts at the National Renal Transplant Centre, Dublin, between January 1992 and December 1999 were retrospectively analyzed. During this time period, patients who were CMV positive and/or had received grafts from CMV-positive donors were administered prophylactic oral acyclovir 800 mg thrice daily, adjusted for calculated creatinine clearance, from the first day post-transplantation. This treatment was continued for three months unless the graft failed or the patient developed CMV disease or died. Graft and patient outcomes were compared in recipients who received acyclovir with those who did not. Over the study period, 935 patients received renal transplants in our center, of whom 487 were administered acyclovir. The incidence of CMV disease was 3.3 cases per 100 patients per annum in those who required prophylaxis. Despite prophylaxis, graft outcomes were found to be significantly worse (p value < 0.001) in the group that qualified for acyclovir. We conclude that acyclovir provides incomplete protection from the negative impact of CMV on graft survival.

Do AshSplit haemodialysis catheters provide better flow rates in the long term?

BACKGROUND

Recently, interventional radiologists have adopted an increasingly prominent role in the placement and management of hemodialysis catheters, as well as in the research and development of new and better catheters. The purpose of this study was to evaluate the viability and hemodialysis efficiency of the AshSplit catheter and the Permcath catheter.

METHODS

204 consecutive patients requiring radiological insertion of hemodialysis catheters were followed, retrospectively, over a 42-month period. Both hemodialysis catheters were placed using a combination of ultrasonic and fluoroscopic guidance and tunneled appropriately. Information collected included catheter insertion sites, insertion complications, catheter duration, and final outcome.

RESULTS

Over the study period of two years, 269 catheters were placed into 204 patients with end stage renal failure. Patients received either an AshSplit (101 patients, 127 catheters) or a Permcath (103 patients, 142 catheters). Vascular access route of choice was the right internal jugular vein (67% AshSplit, 71% Permcath). Insertion complications occurred in 18 patients overall (6.6%), with only 1 requiring further intervention (hemopneumothorax). Flow rates averaged 259 mls/min for AshSplits and 248 mls/min for Permcaths (p < 0.001). Follow-up of catheter viability for 42 months yielded a mean AshSplit catheter duration of 246 days (range 6-932) and 239 days (range 1-1,278) for Permcath (p = 0.46). Reasons for catheter failure and elective catheter removal were similar in both groups; however, Permcaths required significantly more thrombolysis than AshSplits, p < 0.001.

CONCLUSION

The AshSplit provides significantly better flow rates and less thrombolysis compared to the Permcath, with similar catheter dwell times.

Rabbit antithymocyte globulin related decrease in platelet count reduced risk of pediatric renal transplant graft thrombosis

Graft thrombosis is a serious complication in pediatric renal transplantation. We assess a potential protective effect for the decrease in platelet count associated with RATG therapy against pediatric renal transplant graft vascular thrombosis. Between January 1986 and December 1998, 120 kidney transplants were performed in 95 pediatric recipients. Patients were divided into two groups. Group 1 (n = 61), non-RATG group received cyclosporine, azathioprine and steroids, while group 2 (n = 59), RATG group, received in addition, RATG at day 1 and continued for 4-10 days postoperatively. Platelet count prior to transplant, median change in absolute platelet count at 1 and 3 days post-transplant was recorded. Graft thrombosis incidence was examined. Six grafts (5%) developed thrombosis. All were in group 1 (p = 0.028). Median pretransplant platelet count (x10(9)/L) in group 1 was 283 vs. 280 in group 2 (p = 0.921). Median decrease in absolute platelet count (x10(9)/L) from pretransplant levels at one and three days post-transplant for group 1 and 2 was 18 vs. 83 (p </= 0.001) and 39 vs. 105 (p </= 0.001), respectively. Graft thrombosis risk factors were similar in both groups. RATG use was statistically significant (p = 0.044) for reduced risk of graft thrombosis in multivariate analysis. Patients receiving RATG showed significant decrease in both platelet count and graft thrombosis incidence. A role for RATG related effect on platelet count is assumed.

Reduced graft function (with or without dialysis) vs immediate graft function--a comparison of long-term renal allograft survival

BACKGROUND

Delayed graft function (DGF) is a common complication in cadaveric kidney transplants affecting graft outcome. However, the incidence of DGF differs widely between centres as its definition is very variable. The purpose of this study was to define a parameter for DGF and immediate graft function (IGF) and to compare the graft outcome between these groups at our centre.

METHODS

The renal allograft function of 972 first cadaveric transplants performed between 1990 and 2001 in the Republic of Ireland was examined. The DGF and IGF were defined by a creatinine reduction ratio (CRR) between time 0 of transplantation and day 7 post-transplantation of <70 and >70%, respectively. Recipients with reduced graft function (DGF) not requiring dialysis were defined as slow graft function (SGF) patients. The serum creatinine at 3 months, 6 months, 1, 2 and 5 years after transplantation was compared between these groups of recipients. The graft survival rates at 1, 3 and 5 years and the graft half-life for DGF, SGF and IGF recipients were also assessed.

RESULTS

Of the 972 renal transplant recipients, DGF was seen in 102 (10.5%) patients, SGF in 202 (20.8%) recipients and IGF in 668 (68.7%) patients. Serum creatinine levels were significantly different between the three groups at 3 and 6 months, 1, 2 and 5 years. Graft survival at 5 years for the DGF patients was 48.5%, 60.5% for SGF recipients and 75% for IGF patients with graft half-life of 4.9, 8.7 and 10.5 years, respectively.

CONCLUSION

This study has shown that the CRR at day 7 correlates with renal function up to 5 years post-transplantation and with long-term graft survival. We have also demonstrated that amongst patients with reduced graft function after transplantation, two groups with significantly different outcomes exist.

Immunomodulation in type 1 diabetes by NBI-6024, an altered peptide ligand of the insulin B epitope

NBI-6024 is an altered peptide ligand (APL) corresponding to the 9-23 amino acid region of the insulin B chain (B(9-23)), an epitope recognized by inflammatory interferon-gamma-producing T helper (Th)1 lymphocytes in type 1 diabetic patients. Immunomodulatory effects of NBI-6024 administration in recent-onset diabetic patients in a phase I clinical trial (NBI-6024-0003) were measured in peripheral blood mononuclear cells using the enzyme-linked immunosorbent spot assay. Analysis of the mean magnitude of cytokine responses to B(9-23) and NBI-6024 for each cohort showed significant increases in interleukin-5 responses (a Th2 regulatory phenotype) in cohorts that received APL relative to those receiving placebo. A responder analysis showed that Th1 responses to B(9-23) and NBI-6024 were observed almost exclusively in the placebo-treated diabetic population but not in nondiabetic control subjects and that APL administration (five biweekly subcutaneous injections) significantly and dose-dependently reduced the percentage of patients with these Th1 responses. The results of this phase I clinical study strongly suggest that NBI-6024 treatment shifted the Th1 pathogenic responses in recent-onset type 1 diabetic patients to a protective Th2 regulatory phenotype. The significance of these findings on the clinical outcome of disease is currently under investigation in a phase II multidose study.

The impact of donor spontaneous intracranial haemorrhage vs. other donors on long-term renal graft and patient survival

BACKGROUND

Donor cause of death has a significant impact on transplant survival in heart transplants recipients. The objective of this study was to determine if long-term renal allograft and patient survival differed between grafts donated by donors who died of spontaneous intracranial haemorrhage (SIH) compared with those with other causes of death (OCOD).

METHODS

Between 1990 and 2001, 1526 renal transplants were performed (711 SIH donors and 815 OCOD donors) at our unit. Serum creatinine levels at 1 yr, graft half-life and annual graft failure rate were measured for both groups. Renal graft and patient survivals between the groups were compared. Relative risk for SIH donors and other confounding variables was measured using Cox proportional hazards models.

RESULTS

Graft half-life results were obtained for SIH (8 yr) and OCOD (10.13 yr) recipients. Graft and patient survival at 5 and 10 yr was 68.5% and 39.3% respectively for the SIH group vs. 76.8% and 51.9% respectively for the OCOD group (p < 0.001). However, SIH graft recipients were significantly older with more females. After adjustment for differences in baseline variables between the groups, donor cause of death did not have an independent effect on long-term graft or patient survival.

CONCLUSION

Spontaneous intracranial haemorrhage as a cause of donor death, failed to have a significant independent effect on long-term allograft and patient survival.

A population-based study of skin cancer incidence and prevalence in renal transplant recipients

BACKGROUND

Cancers occurring following solid organ transplantation are a rapidly growing public health concern. Defining the extent of the problem has been limited by surveillance systems with incomplete registration of cases and the paucity of reliable national incidence data.

OBJECTIVES

To determine the incidence of all cancers following renal transplantation and to make a detailed examination of trends and patterns associated with postrenal transplant skin cancers.

METHODS

Integration of data from the national renal transplant database and the national cancer registry in Ireland enabled accurate determination of the number of renal transplant recipients (RTRs) with skin cancers and other malignancies in the time period 1 January 1994 to 31 December 2001.

RESULTS

We demonstrated a biphasic increase in skin cancer incidence following renal transplantation, determined by the age at transplantation. There was a steady increase in risk for older RTRs (age 50+ years) from year 2 post-transplant, whereas the increased risk in younger RTRs (age < 50 years) occurred later but much more significantly, reaching 200 times the risk for an age-matched nontransplanted population by year 6 post-transplant. The number of nonmelanoma skin cancers (NMSCs) registered in RTRs accounted for 1% of all NMSCs registered nationally over the study period. The standardized incidence rates for invasive NMSC (33-fold increase) and in situ carcinoma of the skin (65-fold increase) were significantly increased (P < 0.05). The risk for invasive squamous cell carcinoma (SCC) was increased 82-fold compared with the nontransplanted population. Male RTRs were at particular risk of invasive SCC at sun-exposed sites such as the scalp and the external ear. Risk of malignant melanoma and Kaposi sarcoma were also increased relative to the nontransplanted population.

CONCLUSIONS

This comprehensive national study illustrates how rates of skin cancer in Irish RTRs have influenced the national incidence of skin cancer. The high incidence of SCC, basal cell carcinoma and Bowen's disease in the early post-transplant period for older patients and the cumulative risk in younger patients with increased duration of transplantation highlight the importance of implementing early and continued cancer surveillance regimens post-transplant.

Multi organ transplantation: a review of the Irish experience

As the criteria for organ transplantation have broadened, multi organ transplantation has become more common. Calcineurin inhibitor induced end stage renal failure is a common indication for kidney transplantation. We present our experience of 12 kidney transplants, in 11 patients, over a period of 9 years all in the setting of multi-organ transplantation. Kaplan-Meier survival estimates were applied. Estimated patient survival at 1, 3 and 5 years post transplant was 100%, 83% and 66% respectively. Estimated graft survival at 1, 3 and 5 years was 90%, 79% and 63% respectively. The estimated median renal graft survival was 6.2 years. Calcineurin inhibitor toxicity was the most common cause of end stage renal failure in this series of patients. There is a very fine balance between ideal immunosuppression for kidney and other organ transplants. Patients who avoid morbidity such as sepsis or graft rejection enjoy good graft function at 5 years post transplant.

The impact of skin disease following renal transplantation on quality of life

BACKGROUND

The immunosuppressive therapy a patient requires to sustain a functioning renal allograft in the long term is associated with various skin complications. While quality of life (QoL) after renal transplantation has been studied, no publications document the effect of post-transplant dermatological complications on QoL.

OBJECTIVES

The objective of the study was to document the prevalence of the skin diseases that commonly occur in association with post-transplant immunosuppression. A general dermatological quality of life questionnaire, the Dermatology Life Quality Index (DLQI), was used to assess the QoL effect of these cutaneous complications. The study was designed to examine further the impact of age, sex, duration since transplant and immunosuppressive regimen on the DLQI score of renal transplant recipients (RTR).

METHODS

One hundred and seventy-three RTR completed the DLQI, were interviewed and examined for evidence of common post-transplant skin diseases.

RESULTS

Sixteen per cent of RTR had DLQI scores >6, reflecting a significant impact on their QoL. Dry skin, itch, hypertrichosis, sebaceous gland hyperplasia, acne, genital warts and a history of >4 herpes simplex virus type 1 infections in the past year were all found to have a significant impact on the quality of life (P < 0.05). Multivariate analysis revealed that the greatest impact on QoL was in RTR who were younger, female and with multiple skin problems (P < 0.05).

CONCLUSIONS

The dermatological complications of immunosuppressive therapy are common in RTR and can significantly impair QoL in certain individuals. Visible, infectious and cosmetic skin problems had most impact on QoL while a history of skin cancer had a lesser impact. Early dermatological referral and careful choice of immunosuppression may enhance the QoL, particularly in young and female RTR.

A mutation in the TRPC6 cation channel causes familial focal segmental glomerulosclerosis

Focal and segmental glomerulosclerosis (FSGS) is a kidney disorder of unknown etiology, and up to 20% of patients on dialysis have been diagnosed with it. Here we show that a large family with hereditary FSGS carries a missense mutation in the TRPC6 gene on chromosome 11q, encoding the ion-channel protein transient receptor potential cation channel 6 (TRPC6). The proline-to-glutamine substitution at position 112, which occurs in a highly conserved region of the protein, enhances TRPC6-mediated calcium signals in response to agonists such as angiotensin II and appears to alter the intracellular distribution of TRPC6 protein. Previous work has emphasized the importance of cytoskeletal and structural proteins in proteinuric kidney diseases. Our findings suggest an alternative mechanism for the pathogenesis of glomerular disease.