Frequency, potential risk and therapeutic intervention in end-stage renal disease patients with antiphospholipid antibody syndrome: a multicenter study

Antiphospholipid Syndrome and Kidney Involvement

BACKGROUND

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by the development of autoantibodies and the impairment of the coagulation system. Knowledge about this syndrome is increasing over time, but kidney involvement, especially APS nephropathy, still represents a challenge for physicians.

SUMMARY

A "two hit" model has been hypothesized to explain APS pathophysiology, and the role played by some factors, such as the complement system, is becoming more and more clear. From a clinical point of view, along with thrombosis in any site and/or obstetric morbidities, that are the hallmarks of APS, a constellation of several other clinical symptoms is related to APS. These symptoms alone are not sufficient to fulfill Sydney criteria for APS and this could potentially lead to omitting some diagnoses. The mainstay of management of APS is antithrombotic therapy, but there are expectations for new drugs that regulate the immune system. APS could affect the kidneys in many ways and among them, APS nephropathy is an intriguing entity that has been overlooked in recent years. Novel studies on APS nephropathy are lacking.

KEY MESSAGES

In this review, we discuss what we currently know about APS and its relationship with the kidney, with an eye toward the future perspectives. Multicenter studies on APS nephropathy are necessary in order to develop targeted therapies.

How to Deal With Kidney Retransplantation-Second, Third, Fourth, and Beyond

Kidney transplantation is the best health option for patients with end-stage kidney disease. Ideally, a kidney transplant would last for the lifetime of each recipient. However, depending on the age of the recipient and details of the kidney transplant, there may be a need for a second, third, fourth, or even more kidney transplants. In this overview, the outcome of multiple kidney transplants for an individual is presented. Key issues include surgical approach and immunologic concerns. Included in the surgical approach is an analysis of transplant nephrectomy, with indications, timing, and immunologic impact. Allograft thrombosis, whether related to donor or recipient factors merits investigation to prevent it from happening again. Other posttransplant events such as rejection, viral illness (polyomavirus hominis type I), recurrent disease (focal segmental glomerulosclerosis), and posttransplant lymphoproliferative disease may lead to the need for retransplantation. The pediatric recipient is especially likely to need a subsequent kidney transplant. Finally, noncompliance/nonadherence can affect both adults and children. Innovative approaches may reduce the need for retransplantation in the future.

KDIGO Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation

The 2020 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation is intended to assist health care professionals worldwide who evaluate and manage potential candidates for deceased or living donor kidney transplantation. This guideline addresses general candidacy issues such as access to transplantation, patient demographic and health status factors, and immunological and psychosocial assessment. The roles of various risk factors and comorbid conditions governing an individual's suitability for transplantation such as adherence, tobacco use, diabetes, obesity, perioperative issues, causes of kidney failure, infections, malignancy, pulmonary disease, cardiac and peripheral arterial disease, neurologic disease, gastrointestinal and liver disease, hematologic disease, and bone and mineral disorder are also addressed. This guideline provides recommendations for evaluation of individual aspects of a candidate's profile such that each risk factor and comorbidity are considered separately. The goal is to assist the clinical team to assimilate all data relevant to an individual, consider this within their local health context, and make an overall judgment on candidacy for transplantation. The guideline development process followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Guideline recommendations are primarily based on systematic reviews of relevant studies and our assessment of the quality of that evidence, and the strengths of recommendations are provided. Limitations of the evidence are discussed with differences from previous guidelines noted and suggestions for future research are also provided.

Recurrence of disease following organ transplantation in autoimmune liver disease and systemic lupus erythematosus

Disease recurrence after organ transplantation associated with graft failure is a major clinical challenge in autoimmune diseases. Primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC) and autoimmune Hepatitis (AIH) are the three most common (autoimmune liver diseases) ALD for which liver transplantation (LT) is the most effective treatment option for patients with end-stage diseases. Although the 5- and 10-year survival rates of post-LT patients are remarkable (80-84% and 71-79% in PBC, 73-87% and 58-83% in PSC, 76-79% and 67-77% respectively in AIH patients), post-LT disease recurrence is not uncommon. Here, we summarize literature findings on disease recurrence of these ALD with emphasis on the incidence, risk factors and impact on long-term outcome. We noted that the incidence of disease recurrence varies between studies, which ranges from 53% to 10.9% in PBC, 8.2% to 44.7% in PSC and 7% to 42% in AIH. The variations are likely due to differences in study design, such as sample size, duration of studies and follow up time. This is further compounded by the lack of precise clinical diagnosis criteria and biomarkers of disease recurrence in these ALD, variation in post-LT treatment protocols to prevent disease recurrence and a multitude of risk factors associated with these ALD. While recurrence of PBC and AIH does not significantly impact long term outcome including overall survival, recurrent PSC patients often require another LT. Renal transplantation, like LT, is the treatment of choice in patients with end-stage lupus nephritis. While calcineurin inhibitor (CNI) and immunosuppressive drugs have improved the survival rate, post-transplant recurrence of lupus nephritis from surveillance-biopsy proven lupus nephritis range from 30% to 44%. On the other hand, recurrence of post-transplant lupus nephritis from registry survey analysis were only 1.1% to 2.4%. In general, risk factors associated with an increased frequency of post-transplant recurrence of autoimmune diseases are not clearly defined. Large scale multi-center studies are needed to further define guidelines for the diagnosis and clinical management to minimize disease recurrence and improve outcomes of post-transplant patients.

Therapeutic apheresis in kidney transplantation: An updated review

Therapeutic apheresis is a cornerstone of therapy for several conditions in transplantation medicine and is available in different technical variants. In the setting of kidney transplantation, immunological barriers such as ABO blood group incompatibility and preformed donor-specific antibodies can complicate the outcome of deceased- or living- donor transplantation. Postoperatively, additional problems such as antibody-mediated rejection and a recurrence of primary focal segmental glomerulosclerosis can limit therapeutic success and decrease graft survival. Therapeutic apheresis techniques find application in these issues by separating and selectively removing exchanging or modifying pathogenic material from the patient by an extracorporeal aphaeresis system. The purpose of this review is to describe the available techniques of therapeutic aphaeresis with their specific advantages and disadvantages and examine the evidence supporting the application of therapeutic aphaeresis as an adjunctive therapeutic option to immunosuppressive agents in protocols before and after kidney transplantation.

Lupus Nephritis and Kidney Transplantation: Where Are We Today?

Lupus nephritis (LN) is the cause of end-stage kidney disease (ESKD) for 1.9% of the ESKD population in the United States. Although the incidence rates of ESKD from LN stopped rising in recent years, racial disparities in waiting time, pre-emptive kidney transplant, and transplant outcomes still exist. Patients with LN who progress to ESKD tend to be female, of African ancestry, and young. Kidney transplantation is safe in this population and associated with a substantial survival benefit, primarily due to reduced deaths from cardiovascular disease and infection. Transplant outcomes for patients with ESKD due to LN are similar to those without LN.

Treatment in thrombotic antiphospholipid syndrome: a review

Antiphospholipid syndrome an autoimmune disease characterized by thrombosis and/or pregnancy morbidity alongside the presence of antiphospholipid antibodies (aPL). This review evaluates primary and secondary thromboprophylaxis in patients with aPL and thrombotic events. In primary thromboprophylaxis a risk-stratified approach is needed based on aPL, comorbidity with other autoimmune conditions and cardiovascular vascular risk factors. In primary thromboprophylaxis, the efficacy of low-dose aspirin is debatable and requires better-designed controlled studies. So far warfarin has not been shown to improve venous and/or arterial thrombosis incidence in aPL carriers and instead increased safety concerns. The benefit of hydroxychloroquine is inconclusive despite promising data, requiring large, controlled trials. For secondary thromboprophylaxis warfarin seems to be the best option with potential in renal transplant recipients and better efficacy at high intensity, although maintenance of target international normalized ratio needs careful monitoring. Aspirin has not shown to be beneficial, and data on rivaroxaban are limited and contradictory. Despite all data being informative, there are limitations that need to be addressed with robust clinical trials.

Utility of thrombophilia screening in pediatric renal transplant recipients

Thrombosis after kidney transplantation may result in catastrophic outcomes, including graft loss. Thrombophilia has been implicated in post-transplant thrombosis; data, however, are inconclusive on the impact of acquired and inherited thrombophilia and resultant thrombosis in renal graft recipients. We aimed to evaluate whether identifying children with thrombophilia during the pretransplant evaluation predicted post-transplant outcomes. We reviewed 100 kidney transplants performed in 100 children, aged 1-18 years, in a single-center retrospective study. Routine pretransplant comprehensive thrombophilia evaluation was completed. Thrombophilia was demonstrated in 36% patients (N = 36). TEs occurred in 11 patients before kidney transplant. Low PS and antithrombin were found in 9/86 (10.5%) and 2/89 (2.2%) children, respectively. Heterozygosity for FLV and PGM were found in 5/81 (6.2%) and 1/93(1.1%) children, respectively. A post-transplant thrombotic event occurred in 10 children (10%); six involved the renal transplant. The association between a history of a pretransplant thrombotic event and post-operative renal graft thrombosis approached, but did not reach significance (P = 0.071). There was no association between preoperative screening abnormalities and post-operative TEs. Graft loss due to a thrombotic event occurred in two patients; none had underlying thrombophilia. Our data suggest that the utility of universal, comprehensive preoperative thrombophilia testing is not beneficial in determining risk of post-operative graft thrombosis. Thrombophilia testing may be considered in a select population with a history of pretransplant thrombotic event.

Anti-phospholipid Antibodies and Smoking: An Overview

Antiphospholipid syndrome is characterized by the presence of antiphospholipid antibodies, specifically lupus anticoagulant, anticardiolipin antibodies, and anti-β2 glycoprotein-I antibodies. Antiphospholipid syndrome can occur on its own or in association with other autoimmune diseases, most commonly systemic lupus erythematosus (SLE). A connection between cigarette smoking and anti-phospholipid antibodies (aPL) was first reported in the late1980s. Systemic lupus erythematosus patients with aPL are more likely to be smokers than those without aPL. These patients have a particularly high frequency of vascular events. Recently, a potential link between periodontitis, tobacco, and aPL has been proposed. Research has also suggested that periodontitis and Porphyromonas gingivalis infection are associated with citrullination through the action of peptidylarginine deiminase. A strong correlation between smoking and the presence of citrillunated autoantibodies, which are characteristic of rheumatoid arthritis, has also been observed. While many studies have investigated possible links between infection and aPL in patients with autoimmune diseases, the association of smoking with aPL has not been systematically examined. The fact that both aPL and tobacco are risk factors for thrombosis has complicated efforts to evaluate these factors separately. Also, there has been great variability in measurement techniques, and laboratories lack routine methods for differentiating transient and persistent aPL; both of these factors can make interpretation of autoantibody results quite challenging. This review summarizes the clinical evidence supporting a posited link between aPL and smoking, both in patients with a systemic autoimmune disease and in patients with other medical conditions.

Outcomes in Renal Transplant Recipients With Lupus Nephritis-A Single-Center Experience and Review of the Literature

BACKGROUND

Renal transplantation is the renal replacement therapy of choice in patients with end-stage lupus nephritis (LN). The aim of this study was to evaluate the early and late outcomes of renal transplantation in LN patients in a single transplant center.

PATIENTS AND METHODS

This study analyzed the clinical data of patients who received a renal transplant (RTx) at Gdańsk Transplantation Centre between January 1999 and December 2014.

RESULTS

There were 1296 RTx performed between January 1999 and December 2014, including 21 RTx in 19 LN patients (mean age 40 ± 10 years, 89% female). During the follow-up period (between 1 month and 10.5 years), 1 patient died of urosepsis and 1 of pneumonia. Three RTx recipients with antiphospholipid syndrome lost 5 kidney allografts, including 3 due to acute rejection (AR) during the first posttransplantation month. Kidney allograft survival median was 64 months. Delayed graft function (DGF) and AR were observed in 48% and 33% vs 31% and 21% of LN patients and other RTx patients, respectively (P = .1 and P = .16 for DGF and AR, respectively). The most common early posttransplantation complications were AR (31%) and perirenal hematomas (29%), and late complications were urinary tract infections (75%). Recurrence of LN in renal allograft was observed in 1 patient and was successfully treated by increasing the basic immunosuppression.

CONCLUSIONS

Secondary antiphospholipid syndrome has a major influence on the outcomes of RTx in LN patients. Recurrence of LN has no clinical significance.

Hypercoagulability in Kidney Transplant Recipients

Thrombosis remains an important complication after kidney transplantation. Outcomes for graft and deep vein thrombosis are not favorable. The majority of early kidney transplant failure in adults is due to allograft thrombosis. Risk stratification, early diagnosis, and appropriate intervention are critical to the management of thrombotic complications of transplant. In patients with end-stage renal disease, the prevalence of acquired risk factors for thrombosis is significantly high. Because of hereditary and acquired risk factors, renal transplant recipients manifest features of a chronic prothrombotic state. Identification of hereditary thrombotic risk factors before transplantation may be a useful tool for selecting appropriate candidates for thrombosis prophylaxis immediately after transplantation. Short-term anticoagulation may be appropriate for all patients after kidney transplantation.

The dialysis scenario in patients with systemic lupus erythematosus

Although prognosis of lupus nephritis has improved over time, a substantial amount of lupus patients still reach end-stage renal disease and require dialysis. Treatment of these patients can be challenging, since the disease poses a number of problems that can portend a poor prognosis, such as infections, lupus reactivations, vascular access thrombosis and cardiovascular complications. Consensus is lacking among investigators about the real incidence of these complications and related diagnosis and treatment. Moreover, the choice of the type of dialysis treatment and the overall prognosis are still a matter of debate. In this paper, we have reviewed the currently available literature in an attempt to answer the most controversial issues about the topic.

Thrombophilic disorders: a real threat to patients with end-stage renal disease on hemodialysis and at the time of renal transplantation

Management of end-stage renal disease is the mainstay of prevention of renal vascular complications and kidney rejection. We sought to describe the association of some disorders such as diabetic nephropathy, polycystic renal disease, hypertension, and thrombophilia with renal failure and discuss possible mechanisms explaining the implication of the thrombophilic states in kidney allograft thrombosis and renal rejection. Five hundred and sixty-eight patients were included in this case-control study and multivariate analysis was applied. Cases and controls were tested for all major types of thrombophilia. Diabetic nephropathy, autosomal dominant polycystic kidney disease, hypertension, and smoking are the strongest causal agents of end-stage renal disease in Tunisia. It should also be noted that the prevalence of factor V Leiden (P = 0.05) and protein C deficiency (P = 0.005) were significantly higher in ESRD patients awaiting renal transplantation than controls. The present study has raised the possibility that thrombophilic factors may play a pathophysiological role in renal failure. These results will serve as a basis for anticoagulant prophylaxis aimed at preventing kidney rejection and renal allograft thrombosis.

Joint European League Against Rheumatism and European Renal Association-European Dialysis and Transplant Association (EULAR/ERA-EDTA) recommendations for the management of adult and paediatric lupus nephritis

OBJECTIVES

To develop recommendations for the management of adult and paediatric lupus nephritis (LN).

METHODS

The available evidence was systematically reviewed using the PubMed database. A modified Delphi method was used to compile questions, elicit expert opinions and reach consensus.

RESULTS

Immunosuppressive treatment should be guided by renal biopsy, and aiming for complete renal response (proteinuria <0.5 g/24 h with normal or near-normal renal function). Hydroxychloroquine is recommended for all patients with LN. Because of a more favourable efficacy/toxicity ratio, as initial treatment for patients with class III-IV(A) or (A/C) (±V) LN according to the International Society of Nephrology/Renal Pathology Society 2003 classification, mycophenolic acid (MPA) or low-dose intravenous cyclophosphamide (CY) in combination with glucocorticoids is recommended. In patients with adverse clinical or histological features, CY can be prescribed at higher doses, while azathioprine is an alternative for milder cases. For pure class V LN with nephrotic-range proteinuria, MPA in combination with oral glucocorticoids is recommended as initial treatment. In patients improving after initial treatment, subsequent immunosuppression with MPA or azathioprine is recommended for at least 3 years; in such cases, initial treatment with MPA should be followed by MPA. For MPA or CY failures, switching to the other agent, or to rituximab, is the suggested course of action. In anticipation of pregnancy, patients should be switched to appropriate medications without reducing the intensity of treatment. There is no evidence to suggest that management of LN should differ in children versus adults.

CONCLUSIONS

Recommendations for the management of LN were developed using an evidence-based approach followed by expert consensus.

Ten-yr renal allograft survival of patients with antiphospholipid antibody syndrome

BACKGROUND

Long-term allograft survival of antiphospholipid antibody syndrome (APAS) patients as well as patients who have antiphospholipid antibodies but no thrombotic complications remains largely unknown. This study evaluates long-term allograft survival of APA as well as patients with APAS.

METHODS

During the study period from January 1, 1992 through May 31, 2009, 1625 patients with ESRD awaiting renal transplants were screened for APAS. Ninety-four (5.8%) of these patients had circulating levels of anticardiolipin antibodies (ACA) and 39 of these patients had documented evidence of clotting disorders and were diagnosed with APAS. Twenty-one patients with APAS received transplants on either low molecular weight (LMW) heparin or Coumadin as anticoagulation therapy. Of 94 patients with only ACA, 46 received renal transplants. Of the remaining 1492 patients, 1285 patients with no evidence of either ACA or APAS received renal transplants.

RESULTS

Ten-yr allograft survival of patients with APAS treated with Coumadin was similar to those treated with LMW heparin (18% vs. 20%, NS). However, those allograft survivals were significantly lower than those patients positive for ACA (28%) alone (ACA vs. LMW heparin or Coumadin p=0.0001).

CONCLUSION

Despite anticoagulation therapies, patients with APAS have lower long-term graft survival than those patients who have circulating ACA but no APAS.

Beyond immunosuppression – challenges in the clinical management of lupus nephritis

Lupus nephritis remains the most common severe manifestation of SLE with increased risk of death and end-stage renal disease. Although, recent research has focused on the choice of immunosuppressive in its treatment, other factors, including the quality and delivery of healthcare, the management of glucocorticoids and co-morbidity are probably of more importance. There has been significant progress in induction regimes with the successful use of mycophenolate mofetil, low dose intravenous cyclophosphamide and development of sequential regimens whereby cyclophosphamide is followed by an alternative immunosuppressive. However, the attention on the day-to-day management of lupus nephritis in the clinic has merited less attention. In this article, we aim to address more widely the major issues which are encountered regularly in the long-term management of these patients. The overall goals are the reduction of mortality and preservation of renal function.

Disease recurrence in paediatric renal transplantation

Renal transplantation (Tx) is the treatment of choice for end-stage renal disease. The incidence of acute rejection after renal Tx has decreased because of improving early immunosuppression, but the risk of disease recurrence (DR) is becoming relatively high, with a greater prevalence in children than in adults, thereby increasing patient morbidity, graft loss (GL) and, sometimes, mortality rate. The current overall graft loss to DR is 7-8%, mainly due to primary glomerulonephritis (70-80%) and inherited metabolic diseases. The more typical presentation is a recurrence of the full disease, either with a high risk of GL (focal and segmental glomerulosclerosis 14-50% DR, 40-60% GL; atypical haemolytic uraemic syndrome 20-80% DR, 10-83% GL; membranoproliferative glomerulonephritis 30-100% DR, 17-61% GL; membranous nephropathy approximately 30% DR, approximately 50% GL; lipoprotein glomerulopathy approximately 100% DR and GL; primary hyperoxaluria type 1 80-100% DR and GL) or with a low risk of GL [immunoglobulin (Ig)A nephropathy 36-60% DR, 7-10% GL; systemic lupus erythematosus 0-30% DR, 0-5% GL; anti-neutrophilic cytoplasmic antibody (ANCA)-associated glomerulonephritis]. Recurrence may also occur with a delayed risk of GL, such as insulin-dependent diabetes mellitus, sickle cell disease, endemic nephropathy, and sarcoidosis. In other primary diseases, the post-Tx course may be complicated by specific events that are different from overt recurrence: proteinuria or cancer in some genetic forms of nephrotic syndrome, anti-glomerular basement membrane antibodies-associated glomerulonephritis (Alport syndrome, Goodpasture syndrome), and graft involvement as a consequence of lower urinary tract abnormality or human immunodeficiency virus (HIV) nephropathy. Some other post-Tx conditions may mimic recurrence, such as de novo membranous glomerulonephritis, IgA nephropathy, microangiopathy, or isolated specific deposits (cystinosis, Fabry disease). Adequate strategies should therefore be added to kidney Tx, such as donor selection, associated liver Tx, plasmatherapy, specific immunosuppression protocols. In such conditions, very few patients may be excluded from kidney Tx only because of a major risk of DR and repeated GL. In the near future the issue of DR after kidney Tx may benefit from alternatives to organ Tx, such as recombinant proteins, specific monoclonal antibodies, cell/gene therapy, and chaperone molecules.

Antiphospholipid antibodies after renal transplantation and cardiovascular disease

BACKGROUND

The aim was to assess the presence of pre- or post-transplant serum antiphospholipid antibodies (APA) and its association with the development of cardiovascular disease (CVD) in renal transplantation.

METHODS

We studied 138 patients transplanted with a cadaver kidney graft between 1990 and 1998 and with a graft functioning for longer than one yr. One pre-transplant sample and another obtained after transplantation from our serum bank were analyzed. The ELISA used were set up in our laboratory, following established international guidelines, and results were confirmed in three different runs.

RESULTS

23.9% and 31.2% of patients had pre- and post-transplant positive titers of APA, respectively. 16% developed those antibodies de novo after transplantation. Post-transplant CVD was observed in 20.3% of patients but they were not associated with the production of APA in the whole population studied. However, multivariate analysis demonstrated an increased risk (RR 2.27; p = 0.02) for CVD when APA were produced after acute rejection.

CONCLUSIONS

The presence of serum APA alone was not an independent risk factor for CVD after kidney transplantation. Nonetheless, in kidney recipients who produced APA de novo after acute rejection, the control of cardiovascular risk factors must be intensified.

Kidney Disease in Antiphospholipid Syndrome

Renal involvement is a frequent finding in patients with APS. All vascular structures of the kidney may be affected, leading to diverse clinical con-sequences including severe hypertension, proteinuria, hematuria, nephrotic syndrome, and renal failure. In some instances ESRD may occur. Unfortunately, APS patients are at high risk of posttransplant renal thrombosis. The nephropathy of APS is characterized by TMA, FIH, and FCA. The nephropathy of APS should be included in the APS classification criteria. Prospective studies to evaluate management of the diverse renal compromise in APS patients are urgently needed.

Catheter-directed thrombectomy and thrombolysis for acute renal vein thrombosis

PURPOSE

To evaluate the technical success and clinical outcome of the percutaneous treatment of acute renal vein thrombosis (RVT).

MATERIALS AND METHODS

Retrospective review was conducted of all patients with acute RVT treated with percutaneous catheter-directed thrombectomy with or without thrombolysis at one institution between 2000 and 2004. Demographics, comorbid conditions, and clinical outcomes associated with therapy were assessed.

RESULTS

Seven thrombosed renal veins in six patients (mean age, 51.5 +/- 18.8 years) were treated with percutaneous catheter-directed thrombectomy/thrombolysis. Thrombosed renal veins included two allografts and five native veins, and diagnosis was confirmed in all cases by direct renal venography. Inferior vena cava thrombosis was the cause of RVT in one patient, and glomerulopathy was the cause in the remaining patients. Percutaneous mechanical thrombectomy was performed in all cases, and five renal veins were additionally treated with thrombolysis for a mean duration of 22.1 +/- 21.0 hours. Restoration of flow to renal veins was achieved in all thrombosed renal veins. Clinical improvement occurred in all patients: the mean serum creatinine level improved from a preoperative level of 3.3 +/- 1.92 mg/dL to a postoperative level of 1.92 +/- 1.32 mg/dL (P = .008). Mean glomerular filtration rate improved from a preoperative level of 30.8 +/- 23.0 mL/min per 1.73 m(2) to 64.2 +/- 52.4 mL/min per 1.73 m(2) (P = .04). There were no pulmonary emboli or hemorrhagic complications, and no RVT recurrence was documented during a median follow-up of 22.5 months.

CONCLUSIONS

Percutaneous catheter-directed thrombectomy with or without thrombolysis for acute RVT is associated with a rapid improvement in renal function and low incidence of morbidity. It is feasible for native and allograft renal veins and should be considered in patients with acute RVT, particularly in the setting of deteriorating renal function.

A prospective study of the prevalence of heparin-induced antibodies and other associated thromboembolic risk factors in pediatric patients undergoing hemodialysis

Heparin, which is used at high doses in hemodialysis patients, may induce antibodies favoring thromboembolic complications. We prospectively investigated the prevalence of heparin-induced platelet-reactive antibodies in a cohort of 38 pediatric hemodialysis patients, by means of heparin/platelet factor 4 (H/PF4) ELISA and heparin-induced platelet activation assay (HIPA). We also assessed other acquired and congenital hypercoagulable states. Heparin-induced antibodies were detected in 13 and 21% of patients with HIPA and ELISA, respectively. Anti-H/PF4 antibodies were negatively correlated with the number of hemodialysis sessions. These antibodies disappeared after a median time of 6 months despite continuing heparin treatment. The prevalence of antiphospholipid antibodies was 21% (anticardiolipin 10.5%, anti-beta2GPI 13%, and lupus anticoagulant 5%). Blood levels of homocysteine, factor VIII, and fibrinogen were significantly higher and factor II levels were significantly lower in hemodialysis patients than in controls, whereas factor VII, factor IX, and natural coagulation inhibitor levels were similar in patients and controls. Overall, 26 of 38 patients had at least one biomarker of hypercoagulability, but only 1 patient, without anti-H/PF4 antibodies, presented with thrombosis. In conclusion, heparin induces the transient production of anti-H/PF4 antibodies in children undergoing hemodialysis, but other abnormalities probably contribute to hypercoagulability. These findings may help to improve the diagnosis and management of thrombotic events in hemodialysis patients.

Management of the antiphospholipid syndrome

Antiphospholipid antibodies are associated with a hypercoagulable state leading to a wide variety of systemic manifestations and obstetric complications. The different pathologic manifestations can be a result of arterial and venous thrombosis, microthrombotic angiopathy, embolization, obstetric disease, and non-thrombotic phenomenon. Presently, the treatment centers on anticoagulation. Two randomized prospective studies in patients with antiphospholipid syndrome with initial thromboembolic event support the target international normalized ratio of 2.0 to 3.0 for the prevention of future thrombotic events. With pregnancy, the combination of aspirin and heparin is still the standard of care. In addition, non-thrombotic features and any associated autoimmune disease may need to be treated. Underlying risk factors precipitating the thromboembolic phenomenon need to be addressed as well.

Clinical significance of antiphospholipid antibodies on allograft and patient outcome after kidney transplantation

INTRODUCTION

Antiphospholipid antibodies (APA) have acquired great relevance as atherogenic factors. Kidney graft recipients have a higher prevalence of cardiovascular disease (CVD) than the general population, which is not fully explained by the classical vascular risk factors. The aim of this study was to assess the influence of APA on kidney graft and patient outcomes with special focus on CVD.

MATERIALS AND METHODS

One hundred ninety seven cadaveric kidney graft recipients with functioning grafts for more than 1 year underwent determination of serum APA titres (anti-cardiolipin and anti-beta-2 glycoprotein I IgG and IgM antibodies) in one pretransplant serum and in second one obtained at least 1 year after transplantation. In the case of postransplant CVD, the postransplant serum was always chosen before the cardiovascular event. The enzyme linked immunosorbent assay (ELISA) for anti-cardiolipin antibodies was performed in the presence of cofactor.

RESULTS

Twenty-seven percent of patients had pretransplant APA, whereas 15.7% developed postransplant APA de novo. The presence of pretransplant serum APA was not associated with a higher risk of postransplant CVD. The development of postransplant APA de novo showed a relationship to an acute rejection episode (ARE): the frequency of patients who had APA de novo was higher among patients who suffered ARE (18.8% vs 7%, P = .01). In addition, in patients who suffered any ARE, the production of postransplant APA was associated with a higher frequency of postransplant CVD.

CONCLUSIONS

The detection of APA is not an independent risk factor for CVD after kidney transplantation. The inflammatory phenomena secondary to an ARE may be responsible for the de novo production of postransplant APA, which may be associated with the development of postransplant CVD. The control of cardiovascular risk factors should be intensified in this special group of patients.

Management of Hereditary Hypercoagulable Disorders

The clinical management of individuals with hereditary hypercoaguable disorders has evolved from initial broad recommendations of lifelong anticoagulation after first event of venous thromboembolism to a more intricate individualized risk-benefit analysis as studies have begun to delineate the complexity of interactions of acquired and hereditary factors which determine the predilection to thrombosis. The contribution of thrombophilic disorders to risk of thrombotic complications of pregnancy, organ transplantation, central venous catheter and dialysis access placement have been increasingly recognized. The risk of thrombosis must be weighed against risk of long-term anticoagulation in patients with venous thromboembolism. Thrombophilia screening in select populations may enhance outcome.

Prolonged aPTT after kidney transplantation due to transient lupus anticoagulants

BACKGROUND

After kidney transplantation, a renal biopsy may be needed to elucidate the reasons for lack of graft function. If the activated partial thromboplastin time (aPTT) is prolonged, the biopsy will often be postponed, as increased risk of bleeding must be expected. However, aPTT prolongation is not always due to lack of coagulation factors, but can be due to the presence of lupus anticoagulants (LAs). Clinical observations in our department indicated that a large proportion of recently kidney-transplanted patients developed prolonged aPTT values without clinical complications.

METHODS

A prospective study of patients receiving a kidney transplant in 2004 was conducted to investigate the frequency and cause of prolongation of the aPTT.

RESULTS

Twenty-seven patients were included in the study; none had prolonged aPTT or LAs before the transplantation. In the post-transplantation period, 19 patients (70.4%) had a significantly prolonged aPTT. Further investigation showed that for all 19 patients, prolongation was due to acquired antibodies: 13 had developed LAs and six had developed unspecific antibodies. The acquired antibodies were transient and did not affect clinical outcome.

CONCLUSIONS

This is the first study investigating prolonged aPTT in the post-transplantation period. All patients with prolonged aPTT had acquired transient antibodies, i.e. LA or 'LA-like'. If a renal biopsy was requested, 70.4% of the transplanted patients would presumably have their biopsy postponed due to prolonged aPTT, but as LAs do not increase the risk of bleeding, such a delay would be unnecessary. Immediate LA investigation is therefore recommended if a recently transplanted patient requiring surgical procedures has a prolonged aPTT.

Management of end-stage renal disease patients with antiphospholipid antibody syndrome

AIMS

End-stage renal disease (ESRD) patients with antiphospholipid antibody syndrome (APAS) remain at high risk for the development of posttransplant renal thrombosis without the benefit of anticoagulation therapy. This study describes the clinical management of these high-risk patients on anticoagulation therapy.

METHODS

In this study period, 802 patients awaiting renal transplantation were screened for APAS. Twenty-seven of these patients (3%) had APAS. Of these 27, nine patients received cadaveric kidney transplants along with 409 patients who did not have APAS. Of the nine patients, seven were treated with coumadin and the remaining two were treated with heparin.

RESULTS

Of the seven patients treated with coumadin, five did not have thrombotic complications posttransplant. However, three of these patients were taken off coumadin due to bleeding complications at 6 months to 1 year posttransplant. They all returned to dialysis shortly thereafter. The remaining two patients have maintained their allografts on coumadin therapy for 3 and 5 years posttransplants. The other two patients had posttransplant renal thrombosis within 24 hours of their transplant despite coumadin therapy. Of the two patients treated with heparin, one is doing well at 6 years posttransplant while the other had early allograft loss due to thrombosis.

CONCLUSIONS

ESRD patients with APAS may benefit from anticoagulation therapy; however, early allograft loss and bleeding complication are two serious side effects of this therapy.

Renal transplantation in lupus nephritis

Most patients with systemic lupus erythematosus (SLE) are suitable candidates for renal transplantation. However, a number of them may present some disease-related problems. As cardiovascular disease is a leading cause of morbidity and mortality in SLE patients, a careful pretransplant cardiovascular screening is recommended. A search for antiphospholipid antibodies is also useful as the presence of these antibodies can cause an early graft thrombosis. The risk of recurrence of SLE nephritis after transplantation may range between 2 and 30%. In most cases recurrence is characterized by mild histologic lesions. Only rarely does it lead to graft failure. Postransplant immunosuppression does not differ from that used routinely. Whenever possible, a steroid-free immunosuppression should be scheduled to prevent iatrogenic toxicity in patients who have already received long-term steroid treatment. The results of kidney transplantation largely depend on the clinical conditions at transplantation. In patients with poor clinical status or receiving an aggressive immunosuppression it is advisable to postpone the transplant. When some selection criteria are respected, the results of renal trasplantation in SLE patients are at least as good as in other transplant recipients.

Significance of anticardiolipin antibodies on short and long term allograft survival and function following kidney transplantation

The significance of anticardiolipin antibodies (ACAs) prior to renal transplantation is unclear. We studied a cohort of 337 patients who underwent renal transplantation from 1996 to 2001. Follow-up continued until allograft loss, patient death or 31 December 2002. The primary outcome was a composite endpoint of death-censored allograft loss or a 25% reduction in estimated glomerular filtration rate (GFR) from 1-month post-transplant. Secondary outcomes were allograft loss, a 25% reduction in GFR, acute rejection and creatinine at 1 year. IgG and IgM ACA titers were positive (> or =15) in 18.1% of recipients. There were no significant differences at baseline between recipients, except coumadin therapy in those with positive ACA titers (20% vs. 7.4%). Post-transplant, there was no increase in the primary outcome in ACA-positive patients, even after adjustment for anticoagulation with coumadin (HR = 1.42 [0.68, 2.96]). There was no difference in secondary outcomes between those with or without positive titers. Two of five patients with very high titers (>50) who were not anticoagulated had early graft loss. A positive ACA titer prior to kidney transplantation was not associated with inferior renal outcomes after transplantation, although more research is required to address the prognostic significance of very high ACA titers.

Efficacy of anticoagulation therapy in end-stage renal disease patients with antiphospholipid antibody syndrome

BACKGROUND

End-stage renal disease (ESRD) patients with antiphospholipid antibody syndrome (APAS) remain at high risk for the development of renal thrombosis without the benefit of anticoagulation therapy. This study examines the efficacy of anticoagulation therapy in this high-risk patient population.

METHOD

Of nine APAS renal-transplant patients, seven were treated with coumadin, whereas two were treated with heparin.

RESULTS

Of the two patients treated with heparin, one had early allograft loss, whereas the other patient is doing fine at 5 years posttransplant. Of the seven 7 patients treated with coumadin, two patients are doing well at 2 and 3 years posttransplant, two had early allograft loss, the remaining three patients returned to dialysis after they were taken off of the coumadin at 6, 12, and 20 months posttransplant because of bleeding complications.

CONCLUSIONS

Anticoagulation therapy is beneficial to some but not all APAS patients. In addition, bleeding complications are a serious side effect of this therapy.

Hypercoagulability in renal transplant recipients. Identifying patients at risk of renal allograft thrombosis and evaluating strategies for prevention

Renal transplantation improves survival and quality of life for patients with end-stage renal disease (ESRD). Improvements in immunosuppressive therapy have reduced early allograft loss due to acute rejection to very low levels. Early allograft loss, due to acute thrombotic complications, remains a constant and proportionally increasing complication of renal transplantation. Identifying risk factor(s) for thrombosis amenable to preventive strategies has been elusive. Epidemiological studies have attempted to define risk in terms of modifiable (drugs, dialysis modality, surgical procedure) and non-modifiable (age, diabetes mellitus, vascular anomalies) factors, or identify changes in coagulation or fibrinolysis promoting a more thrombotic state. Most recently the evolution of thrombophilia research has established the potential for inherited hypercoagulability to predispose to acute allograft thrombosis. Inheritance of the factor V Leiden (FVL), prothrombin G20210A mutation, or the presence of antiphospholipid antibodies (APA) may increase the risk of renal allograft thrombosis approximately 3-fold in selected patients. Patients with ESRD due to systemic lupus erythematosus (SLE) appear at particularly high risk of thrombosis, especially if they have either APA or detectable beta(2)-glycoprotein-1. Data for other hypercoagulable states such as hyperhomocystinemia or the C677T polymorphism of the methylenetetrahydrofolate reductase gene are deficient. Patients with APA, FVL, or prothrombin G20210A mutation also appear to have greater graft loss due to vascular rejection, possibly reflecting immunological injury upon the vascular wall exacerbated or induced by the prothrombotic state. While substantial in vitro data suggest cyclosporine is prothrombotic, an independent clinical association with allograft thrombosis is unproven. Interventions to reduce thrombotic risk including heparin, warfarin, and aspirin have been evaluated in both selected high-risk groups (heparin and warfarin) and unselected populations (heparin and aspirin). In unselected patients at low clinical risk, aspirin (75-150 mg/day) with or without a short period of unfractionated heparin (5000U twice a day for 5 days) appears to reduce the risk of renal allograft thrombosis significantly with a low risk of bleeding, especially when compared with low molecular weight heparins which risk accumulation in renal failure. In high-risk groups (identified thrombophilic risk factor, previous thrombosis, or SLE) longer period of heparin, with or without aspirin and maintenance with warfarin, should be considered. Re-transplantation following graft loss due to vascular thrombosis can be undertaken with a low risk of recurrence. Further prospective studies evaluating both putative risk factors and intervention strategies are required to determine whether routine clinical screening for thrombophilic factors is justified.

Prothrombotic disorders in uremic type-1 diabetics undergoing simultaneous pancreas and kidney transplantation

BACKGROUND

Although prothrombotic disorders (PTD) are known to increase the risk of graft failure in kidney transplantation only, there are no data on PTD in simultaneous pancreas and kidney transplantation (SPK).

METHODS

Forty-seven SPK performed between September 2000 and July 2002 underwent routine screening for PTD. Data were retrospectively analyzed in view of complications (relaparotomy, graft thrombosis, pancreatitis, rejection) and graft function (HbA1c, serum creatinine) 3 months posttransplantation.

RESULTS

Twenty-five of forty-seven (53.2%) patients had 30 PTDs. Homozygous mutations of the MTHFR gene (C677T) were found in six, factor-V Leiden mutation (homo- or heterozygous G1691A) in seven, and prothrombin mutation (20210A) in one patient (group 1). Group 2 consists of deficiencies of protein C (n=1), of protein S (n=12), of antithrombin (n=1), and antiphospholipid syndromes (n=2). Overall, PTD had no influence on graft thrombosis (P=0.36) or rejection (P=0.56). In patients with homozygous mutations, relaparotomies were more often necessary than in patients without mutations (42.9% vs. 11.8%, P=0.046). In group 1, there was a trend toward a higher incidence of graft pancreatitis than in patients without mutations (38.5% vs. 14.7%, P=0.075). Three months posttransplantation, HbA1c was 6.0% in patients with and 5.5% in patients without PTD (P=0.023). With regard to serum creatinine, no significant differences were observed.

CONCLUSION

PTD are frequent in type-1 diabetics receiving SPK and may have a role in relaparotomies, graft pancreatitis, and pancreas graft function.

Coagulation: consultative hemostasis

Clinical hematologists are frequently consulted for the care of hospitalized patients with complicated coagulopathies. This chapter provides an update on the scientific and clinical advances noted in disseminated intravascular coagulation (DIC) and discusses the challenges in hemostasis consultation. In Section I, Dr. Marcel Levi reviews advances in our understanding of the pathogenic mechanisms of DIC. Novel therapeutic strategies that have been developed and evaluated in patients with DIC are discussed, as are the clinical trials performed in patients with sepsis. In Section II, Dr. Lawrence Leung provides an overview of the challenging problems in thrombosis encountered in the inpatient setting. Patients with deep vein thrombosis that is refractory to conventional anticoagulation and those with extensive mesenteric thrombosis as well as the evaluation of a positive PF4/heparin ELISA in a post-operative setting are discussed. Novel treatments for recurrent catheter thrombosis in dialysis patients is addressed as well. In Section III, Dr. Julie Hambleton reviews the hemostatic complications of solid organ transplantation. Coagulopathy associated with liver transplantation, contribution of underlying thrombophilia to graft thrombosis, drug-induced microangiopathy, and the indication for postoperative prophylaxis are emphasized. Dr. Hambleton reviews the clinical trials evaluating hemostatic agents in patients undergoing liver transplantation.

Repeated graft loss caused by recurrent hepatic artery thrombosis after liver transplantation

Hepatic artery thrombosis (HAT) is a main cause of graft loss and patient mortality after orthotopic liver transplantation (OLT). Several surgical and nonsurgical risk factors have been associated with HAT. Retransplantation often is the only possible treatment for this complication; however, the incidence of recurrence of HAT after retransplantation and the underlying conditions of this occurrence have never been investigated. Of 629 consecutive recipients transplanted at a single institution, 24 underwent retransplantion for HAT: in 4 of them (16%), HAT recurred in the second graft; 3 of these patients lost their first graft because of late HAT, whereas another one lost 4 consecutive grafts for early HAT. Antiphospholipid syndrome and paroxysmal nocturnal hemoglobinuria were diagnosed in three and one of these patients, respectively. Recurrent HAT is an uncommon occurrence that, in our experience, was linked to specific thrombophilic conditions; careful screening of these disorders should be included in the pretransplant workup, and adequate prophylaxis is advisable.