Severe vascular lesions and poor functional outcome in kidney transplant recipients with lupus anticoagulant antibodies

Antiphospholipid Syndrome Nephropathy with Acute Thrombotic Microangiopathy after Renal Transplantation

We experienced a 36-year-old man with lupus nephritis and antiphospholipid syndrome (APS) who received a donor kidney from his father. Twenty-two months after transplantation, at a time of poor adherence to immunosuppressants and warfarin, the patient developed sudden graft loss due to hemolytic uremic syndrome with rapid deterioration of renal function, thrombocytopenia, and hemolytic anemia. A kidney biopsy showed thrombotic microangiopathy (TMA) related to platelet thrombus formation; however, there was no recurrence of lupus and no findings suggestive of post-transplant rejection, so acute TMA associated with APS was thought to be the cause of the graft loss. This case highlights the importance of instructing patients with lupus nephritis to adhere to treatment with warfarin, a therapeutic drug for APS.

Antiphospholipid Syndrome in Renal Allograft Recipients-A Long-Term Multicenter Analysis

Antiphospholipid syndrome (APS) is a devastating autoimmune disease and in renal transplant recipients may result in allograft thrombosis or in extra-renal manifestation, mostly venous thromboembolism. There are many non- and immune risk factors affecting renal allograft in recipients with APS. However, renal allograft outcome in recipients with APS without APS nephropathy remains unknown. Aim: The aim of the study was to assess renal allograft function and survival in recipients with APS. Methods: Retrospective, multicenter study included 19 adult renal recipients with definite APS (primary or lupus-related) from three Polish transplant centers. Renal allograft function was assessed using serum creatinine concentration (SCr1) at 3rd month post-transplant and at the end of the observation (SCr2) and glomerular filtration rate (GFR) was estimated based on modification of diet in renal disease (MDRD) formula. General linear model was used to assess 12 month GFR change over time. Kaplan-Meier curves and restricted mean survival time were used for allograft survival. Matched control group consisted of 21 stable renal recipients without history of thrombosis and without anticoagulation/antiplatelet treatment. Results: The study group differs in induction therapy (p = 0.019), high-urgency procedure (p = 0.04), proteinuria (p = 0.0058), primary disease (lupus) (p < 0.0001), re-transplantation in primary APS (p = 0.0046) and shorter time since engraftment to SCr2 (p = 0.016). Primary APS was more often diagnosed post-transplant (p = 0.0005). Allograft biopsy revealed thrombotic microangiopathy (TMA) with acute rejection (AR) or isolated AR vs AR or chronic rejection in controls but did not reach significance (p = 0.054). Renal allograft function was inferior in the study group but did not reach significance: mean SCr2 (mg/dL) was 2.18 ± 1.41 and 1.5 ± 0.68 in controls, respectively, p = 0.27; mean GFR2 (ml/min/1.73m2) was 39.9 ± 20.83 and 51.23 ± 19.03, respectively, p = 0.102. Renal allograft duration was inferior in patients with APS and was (in years) 11.22 ± 1.44 vs. 14.36 ± 0.42, respectively, p = 0.037, in patients with primary APS (p = 0.021), in patients with APS diagnosed post-transplant (p = 0.012) but not in lupus-related APS (p = ns). Fifteen year renal allograft survival was inferior in APS vs. controls (73,86% vs. 90.48%, respectively, p = 0.049). Conclusions: Recipients with APS are at higher risk for allograft loss due to immune and non-immune causes. Renal allograft survival was inferior in recipients with APS and renal function remains impaired but stable.

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.

Kidney disease in antiphospholipid antibody syndrome: Risk factors, pathophysiology and management

Antiphospholipid antibody syndrome (APLS) is a rare autoimmune disease characterized by recurrent arterial and venous thromboembolic events, pregnancy related complications as well as the persistent detection of antiphospholipid antibodies at a 12 week interval. Renal complications tend to occur in 3% of APLS patients, with renal artery stenosis being the most common kidney related complication. Renal pathology may be subdivided into macro as well as microvascular thrombotic complications with stenosis, thrombosis and infarction representing the principle macrovascular events and APLS nephropathy representing the predominant microvascular complication. APLS related kidney disease may present with an array of heterogenous manifestations ranging from hematuria and non-nephrotic range proteinuria to hypertension or as part of a severe, life threatening and fulminant multiorgan failure disorder known as catastrophic antiphospholipid antibody syndrome (CAPS). Management of APLS related renal complications depends on the site of vascular injury, the thromboembolic risk profile based on the subtype, isotype and titer of the autoantibodies as well as the severity of the injury. Primary prophylaxis in these patients primarily revolves around the use of low dose aspirin, with prophylactic anticoagulation during events that increase thromboembolic like surgery and hospitalization. Anticoagulation is the cornerstone of treatment of APLS related kidney disease with INR targets varying depending on the associated venous or arterial thrombosis. Immunosuppression with the likes of rituximab, mTOR inhibitors, eculizumab and belimumab have been used with some success, but lack randomized control trial validation for their use. Pulsed corticosteroids with Plasmapheresis and intravenous immunoglobulins is the recommended treatment for CAPS.

Successful Treatment of Catastrophic Antiphospholipid Syndrome Using Rituximab: Case Report and Review of the Literature

BACKGROUND

Kidney involvement is a frequent complication of systemic lupus erythematosus (SLE) and kidney biopsy is essential in differentiating lupus nephritis (LN) from thrombotic microangiopathy (TMA) secondary to antiphospholipid autoantibodies (aPL). Association between antiphospholipid syndrome (APS) and acquired hemophilia due to inhibitors was very rarely described in SLE patients.

CASE PRESENTATION

We present the case of a 61-year-old male diagnosed with SLE who acquired deficiency of clotting factor VIII due to circulating inhibitors, admitted for acute kidney injury (AKI), microangiopathic hemolytic anemia, thrombocytopenia, and diplopia. Kidney biopsy showed TMA due to APS, but no signs of LN. Head computed tomography identified low dense areas in the white matter, suggesting small blood vessels' involvement. A diagnosis of probable catastrophic antiphospholipid syndrome (CAPS) was established and treatment with low molecular weight heparin, intravenous methylprednisolone, plasmapheresis, and rituximab was initiated, followed by resolution of AKI, diplopia, and TMA with complete depletion of CD19+B-lymphocytes (CD19+B-Ly) after one month. We further review the current knowledge regarding pathogenesis and management of CAPS in SLE patients.

CONCLUSIONS

Targeted therapy was possible after kidney biopsy, improving renal and general prognosis. CD19+B-Ly repopulation preceded biological relapse, so monitoring of CD19+B-Ly may serve as a tool to predict relapses and guide rituximab therapy.

ISHLT consensus document on lung transplantation in patients with connective tissue disease: Part I: Epidemiology, assessment of extrapulmonary conditions, candidate evaluation, selection criteria, and pathology statements

Patients with connective tissue disease (CTD) and advanced lung disease are often considered suboptimal candidates for lung transplantation (LTx) due to their underlying medical complexity and potential surgical risk. There is substantial variability across LTx centers regarding the evaluation and listing of these patients. The International Society for Heart and Lung Transplantation-supported consensus document on lung transplantation in patients with CTD standardization aims to clarify definitions of each disease state included under the term CTD, to describe the extrapulmonary manifestations of each disease requiring consideration before transplantation, and to outline the absolute contraindications to transplantation allowing risk stratification during the evaluation and selection of candidates for LTx.

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.

Recommendations of the Spanish Rheumatology Society for Primary Antiphospholipid Syndrome. Part II: Obstetric Antiphospholipid Syndrome and Special Situations

OBJECTIVE

The difficulty in diagnosis and the spectrum of clinical manifestations that can determine the choice of treatment for antiphospholipid syndrome (APS) has fostered the development of recommendations by the Spanish Society of Rheumatology (SER), based on the best possible evidence. These recommendations can serve as a reference for rheumatologists and other specialists involved in the management of APS.

METHODS

A panel of 4rheumatologists, a gynaecologist and a haematologist with expertise in APS was created, previously selected by the SER through an open call or based on professional merits. The stages of the work were: identification of the key areas for the document elaboration, analysis and synthesis of the scientific evidence (using the Scottish Intercollegiate Guidelines Network, SIGN levels of evidence) and formulation of recommendations based on this evidence and formal assessment or reasoned judgement techniques (consensus techniques).

RESULTS

Forty-six recommendations were drawn up, addressing 5main areas: diagnosis and evaluation, measurement of primary thromboprophylaxis, treatment for APS or secondary thromboprophylaxis, treatment for obstetric APS and special situations. These recommendations also include the role of novel oral anticoagulants, the problem of recurrences or the key risk factors identified in these subjects. This document reflects the last 25, referring to the areas of: obstetric APS and special situations. The document provides a table of recommendations and treatment algorithms.

CONCLUSIONS

Update of SER recommendations on APS is presented. This document corresponds to part II, related to obstetric SAF and special situations. These recommendations are considered tools for decision-making for clinicians, taking into consideration both the decision of the physician experienced in APS and the patient. A part I has also been prepared, which addresses aspects related to diagnosis, evaluation and treatment.

The Role of Cardiolipin and Mitochondrial Damage in Kidney Transplant

Chronic kidney disease (CKD) is highly incident and prevalent in the world. The death of patients with CKD is primarily due to cardiovascular disease. Renal transplantation (RT) emerges as the best management alternative for patients with CKD. However, the incidence of acute renal graft dysfunction is 11.8% of the related living donor and 17.4% of the cadaveric donor. Anticardiolipin antibodies (ACAs) or antiphospholipid antibodies (APAs) are important risk factors for acute renal graft dysfunction. The determination of ACA or APA to candidates for RT could serve as prognostic markers of early graft failure and would indicate which patients could benefit from anticoagulant therapy. Cardiolipin is a fundamental molecule that plays an important role in the adequate conformation of the mitochondrial cristae and the correct assembly of the mitochondrial respiratory supercomplexes and other proteins essential for proper mitochondrial function. Cardiolipin undergoes a nonrandom oxidation process by having pronounced specificity unrelated to the polyunsaturation pattern of its acyl groups. Accumulation of hydroxyl derivatives and cardiolipin hydroperoxides has been observed in the affected tissues, and recent studies showed that oxidation of cardiolipin is carried out by a cardiolipin-specific peroxidase activity of cardiolipin-bound cytochrome c. Cardiolipin could be responsible for the proapoptotic production of death signals. Cardiolipin modulates the production of energy and participates in inflammation, mitophagy, and cellular apoptosis. The determination of cardiolipin or its antibodies is an attractive therapeutic, diagnostic target in RT and kidney diseases.

[Lupus nephritis]

Systemic lupus erythematosus is the most characteristic of auto-immune disorders that can lead to tissue damage in many organs, including kidney. Lupus nephritis occurs in 10 to 40% of lupus patients. Its clinical hallmark is the appearance of a proteinuria as soon as a 0.5 g/g or 0.5 g/d threshold, which calls for a renal histological evaluation in order to determine the lupus nephritis severity and the need for specific therapy. More than half of renal biopsies lead to the diagnosis of active lupus nephritis-class III or class IV A according to the ISN/RPS classification-that are the most severe in regards to renal prognosis and mortality. Their treatment aims to their clinical remission and to the prevention of relapse with minimal adverse effects for eventually the preservation of renal function, the prevention of other irreversible damage, and the reduction of risk of death. The remission is obtained through induction therapies of which the association of high dose steroids and cyclophosphamide is the most experienced. When this association must be challenged by the prevention of side-effect, in particular infertility, mycophenolate can be given instead of cyclophosphamide. Maintenance therapy, for the prevention of relapse, consists in mycophenolate or in azathioprine, mycophenolate being the most efficient however associated with a high risk of teratogenicity. Withdrawal of maintenance therapy is possible after two to three years in absence of high risk factors of relapse of lupus nephritis, however a reliable assessment of the risk of relapse is still lacking. Only pure membranous lupus nephritis (pure class V) associated with high level proteinuria requires specific therapies that usually associates steroids and an immunosuppressive drug. However, their choice hierarchy and even the use of less immunosuppressive strategies remain to be determined in terms of benefice over risk ratios. In spite of its trigger effect on lupus activity, pregnancy can be safe and successful if scheduled in the lowest risk periods with close multidisciplinary monitoring before, during and after. When necessary, renal replacement therapy does not require specific adaptation, renal transplantation is the best option when possible, as early as possible.

Effect of Thrombophilic Factors on Renal Graft Function: A Single-Center Experience

BACKGROUND

Optimization of immunosuppressive therapy reduced the incidence of acute rejection, and therefore vascular complications, including graft thrombosis, which have emerged as the main cause of graft loss in the early post-transplant period. A thrombophilic condition may lead to renal graft loss. The aim of the study was to assess renal graft function in thrombophilic renal recipients receiving anticoagulation treatment.

METHODS

This is a retrospective study including 29 renal recipients (ktx group) with a history of thrombosis and confirmed thrombophilic factor. Graft function was evaluated by median serum creatinine concentration at the third month after ktx (SCr₁) and at the end of the observation (SCr₂) with respect to hypercoagulability (factor V Leiden [FVL], mutation G20210A, antiphospholipid antibodies, deficiency of protein S [PS] or C [PC], factor VIII >200%).

RESULTS

Recipients underwent retransplantation because of graft thrombosis (P < .001). They more often underwent urgent transplantation (P = .008), received induction therapy (P = .021), underwent an indication other than protocol biopsy (P = .001), or experienced acute rejection (P = .042). Differences in graft function (SCr₂) were found at the end of observation (ktx group vs controls 1.9 mg/dL vs 1.3 mg/dL, respectively, P = .014). Multivariate analysis revealed inferior thrombophilic graft function in the model with SCr₁ <2 mg/dL (odds ratio 0.07, 95% confidence interval 0.01-0.57, P = .014) and in the model with SCr₂ <2 mg/dL (odds ratio 0.15; 95% confidence interval 0.04-0.54, P = .004). The incidence of antiphospholipid syndrome was 31%; FVIII, 31%; FVL, 24.1%; and PC/PS, 13.8%. After anticoagulation was introduced no thromboembolic events or bleeding complications occurred.

CONCLUSION

Hypercoagulability is not a contraindication to ktx but may worsen graft function. Post-transplant care in thrombophilic recipients is demanding (retransplantation, immunization, protocol biopsy, anticoagulation), but is the only means by which to maintain a graft.

Complete necrosis of graft ureter following renal transplant in a patient with primary antiphospholipid syndrome: A case report

Complete necrosis of the graft ureter is a rare but serious complication following kidney transplant. In a patient with antiphospholipid syndrome, a combination of factors such as arterial thromboembolism, hematoma formation, and surgical collateral damage can cause ischemia of the graft ureter. Preoperative optimization of disease activity and coagulation with meticulous preservation of ureteric perfusion may help in prevention.

Antiphospholipid Syndrome Nephropathy: From Pathogenesis to Treatment

Kidney damage is a well-recognized complication of the antiphospholipid syndrome (APS), either primary or systemic lupus erythematosus (SLE)-associated APS. Kidney involvement in APS involves a variety of manifestations, such as renal artery thrombosis or stenosis, renal vein thrombosis, allograft loss due to thrombosis after kidney transplantation, and injury to the renal microvasculature, also known as APS nephropathy. Biopsy in patients with APS nephropathy includes acute thrombotic microangiopathy lesions and chronic intrarenal vascular lesions such as interlobular fibrous intimal hyperplasia, arterial and arteriolar recanalizing thrombosis, fibrous arterial occlusion, and focal cortical atrophy. The most frequent clinical features are hypertension, microscopic hematuria, proteinuria (ranging from mild to nephritic levels), and renal insufficiency. It is uncertain whether antiphospholipid antibodies or other factors are implicated in the development of APS nephropathy, and whether it is driven mainly by thrombotic or by inflammatory processes. Experimental models and clinical studies of thrombotic microangiopathy lesions implicate activation of the complement cascade, tissue factor, and the mTORC pathway. Currently, the management of APS nephropathy relies on expert opinion, and consensus is lacking. There is limited evidence about the effect of anticoagulants, and their use remains controversial. Treatment approaches in patients with APS nephropathy lesions may include the use of heparin based on its role on complement activation pathway inhibition or the use of intravenous immunoglobulin and/or plasma exchange. Targeted therapies may also be considered based on potential APS nephropathy pathogenetic mechanisms such as B-cell directed therapies, complement inhibition, tissue factor inhibition, mTOR pathway inhibition, or anti-interferon antibodies, but prospective multicenter studies are needed to address their role.

Renal Involvement in Antiphospholipid Syndrome

Antiphospholipid syndrome is a complex autoimmune disease, characterized by the presence of vascular thrombosis, obstetric, hematologic, cutaneous, and cardiac manifestations. Renal disease in patients with antiphospholipid syndrome was not recognized in the first descriptions of the disease, but later on, the renal manifestations of the syndrome have been investigated widely. Renal manifestations of antiphospholipid syndrome conform a wide spectrum of diverse renal syndromes. Hypertension is one of the most frequent, but less commonly recognized renal alteration. It can be difficult to control as its origin is renovascular. Renal vascular thrombosis can be arterial or venous. Other alterations are renal infarction and vascular thrombosis in arterial territories. Venous thrombosis can be present in primary and secondary antiphospholipid syndrome; it presents with worsening of previous proteinuria or de novo nephrotic syndrome, hypertension and renal failure. Antiphospholipid syndrome nephropathy is a vascular disease that affects glomerular tuft, interstitial vessels, and peritubular vessels; histopathology characterizes the renal lesions as acute or chronic, the classic finding is thrombotic microangiopathy, that leads to fibrosis, tubule thyroidization, focal cortical atrophy, and glomerular sclerosis. Antiphospholipid syndrome nephropathy can also complicate patients with systemic lupus erythematosus, and there is vast information supporting the worse renal prognosis in this group of patients with the classic histopathologic lesions. Treatment consists of anticoagulation, as for other thrombotic manifestations of antiphospholipid syndrome. There is some evidence of glomerulonephritis as an isolated lesion in patients with antiphospholipid syndrome. The most frequently reported glomerulonephritis is membranous; with some reports suggesting that immunosuppressive treatment may be effective. Patients with end stage renal disease commonly are positive for antiphospholipid antibodies, but it is not clear what is the role of aPL in this setting. Patients with vascular access may have complications in the presence of antibodies so that anticoagulation is recommended. Patients ongoing renal transplant with persistent antiphospholipid antibody positivity may have early and late graft failure.

[Current insights about recurrence of glomerular diseases after renal transplantation]

Recurrence of glomerular disease after renal transplantation is a frequent cause of graft loss. Incidence, risk factors and outcome of recurrence are widely due to the underlying glomerular disease. Graft biopsy analysis is required to confirm the definitive diagnosis of recurrence and to start an appropriate therapy that, in some cases, remains challenging to prevent graft failure. Increased use of protocol biopsy and recent advances in our understanding of the pathogenesis of some glomerular diseases with the identification of some relevant biomarkers provide a unique opportunity to initiate kidney-protective therapy at early stages of recurrence on the graft. This review summarizes our current knowledge on the management of many recurrent primary and secondary glomerulonephritis after kidney transplantation.

Long-term survival of kidney grafts in lupus nephritis: a Mexican cohort

Kidney transplant for patients with lupus nephritis (LN) has satisfactory outcomes in studies with short-term or mid-term follow up. Nevertheless, information about long-term outcomes is scarce. We performed a retrospective matched-pair cohort study in 74 LN recipients compared with 148 non-LN controls matched by age, sex, immunosuppressive treatment, human leukocyte antigen (HLA) matches, and transplant period in order to evaluate long-term outcomes of kidney transplant in LN recipients. Matched pairs were predominantly females (83%), median age at transplant surgery of 32 years (interquartile range 23–38 years), and 66% received a graft from a living related donor. Among LN recipients, 5-, 10-, 15-, and 20-year graft survival was 81%, 79%, 57% and 51%, respectively, and it was similar to that observed in controls (89%, 78%, 64%, and 56%, respectively). Graft loss (27% vs. 21%, p = 0.24) and overall survival ( p = 0.15) were not different between LN recipients and controls. Also, there was no difference in episodes of immunological rejection, thrombosis, or infection. Only six LN recipients had biopsy-proven lupus recurrence and three of them had graft loss. In a cohort with a long follow up of kidney transplant recipients, LN recipients had similar long-term graft survival and overall outcomes compared with non-lupus recipients when predictors are matched between groups.

Vascular Manifestations in Antiphospholipid Syndrome (APS): Is APS a Thrombophilia or a Vasculopathy?

PURPOSE OF REVIEW

Antiphospholipid antibody syndrome (APS) is characterized primarily by thrombosis and pregnancy morbidity. Chronic vascular lesions can also occur. While the underlying mechanisms of these vascular lesions are not entirely known, there have been multiple theories describing the potential process of vasculopathy in APS and the various clinical manifestations associated with it.

RECENT FINDINGS

Recently, it has been demonstrated that endothelial proliferation in kidneys can be explained by the activation of the mammalian target of rapamycin complex (mTORC) pathway by antiphospholipid antibodies (aPL). These data support the existence of an APS-related vasculopathy in different locations which can explain-in part-the different manifestations of APS. This review focuses on the various manifestations of APS as a result of APS-related vasculopathy, as well as pathophysiology, current screening, and treatment options for clinicians to be aware of.

Diagnosing antiphospholipid syndrome: 'extra-criteria' manifestations and technical advances

First described in the early 1980s, antiphospholipid syndrome (APS) is a unique form of acquired autoimmune thrombophilia in which patients present with clinical features of recurrent thrombosis and pregnancy morbidity and persistently test positive for the presence of antiphospholipid antibodies (aPL). At least one clinical (vascular thrombosis or pregnancy morbidity) and one lab-based (positive test result for lupus anticoagulant, anticardiolipin antibodies and/or anti-β2-glycoprotein 1 antibodies) criterion have to be met for a patient to be classified as having APS. However, the clinical spectrum of APS encompasses additional manifestations that can affect many organs and cannot be explained exclusively by patients being in a prothrombotic state; clinical manifestations not listed in the classification criteria (known as extra-criteria manifestations) include neurologic manifestations (chorea, myelitis and migraine), haematologic manifestations (thrombocytopenia and haemolytic anaemia), livedo reticularis, nephropathy and valvular heart disease. Increasingly, research interest has focused on the development of novel assays that might be more specific for APS than the current aPL tests. This Review focuses on the current classification criteria for APS, presenting the role of extra-criteria manifestations and lab-based tests. Diagnostic approaches to difficult cases, including so-called seronegative APS, are also discussed.

Living donor renal transplantation in patients with antiphospholipid syndrome: A case report

INTRODUCTION

Antiphospholipid syndrome (APS), autoantibodies directed against phospholipid-binding proteins are associated with cause vascular thrombosis. Patients with APS requiring renal transplantation are at risk of early graft loss due to arterial or venous thrombosis, or thrombotic microangiopathy (TMA). Here, we report 3 cases of successful renal transplantation in patients with APS.

CLINICAL FINDINGS

A 53-year-old man with end-stage renal disease (ESRD) had experienced bilateral deep venous thrombosis (DVT) in the lower extremities 16 years ago and was administered warfarin. However, he frequently experienced recurrent DVT despite of anticoagulation therapy. Before the surgery, APS was confirmed based on positive results lupus anticoagulant in serological tests. A 40-year-old man with polycystic kidney disease and a history recurrent DVT tested positive for lupus anticoagulant and anticardiolipin antibodies. Lastly, a 42-year-old woman with ESRD was diagnosed with APS 7 years ago. She also developed DVT and tested positive for lupus anticoagulant and anti-B2-glycoprotein 1.

THE ANTICOAGULATION PROTOCOL WAS AS FOLLOWS IN ALL CASES

Warfarin was stopped 5 days before living donor renal transplantation and intravenous heparin therapy was started. During surgery, bolus heparin injections (3000 U) were administered to prevent arterial or venous thrombosis. Heparin was substituted with warfarin on postoperative day 4. The third patient (42/F) developed clinical rejection indicated by increased serum creatinine levels and donor-specific antibodies (DSA) and received steroid pulse therapy, plasmapheresis, and rituximab. This treatment restored graft function to within the normal range. The latest graft function in all patients was maintained at normal levels in the outpatient clinic.

CONCLUSIONS

Living donor renal transplantation may be successful in patients with APS following perioperative anticoagulation therapy. However, because of the high risk of TMA or vascular thrombosis in the early postoperative period, close monitoring for hypercoagulability and continuous anticoagulation is essential for maintaining graft function.

Antiphospholipid syndrome and kidney disease

The antiphospholipid syndrome is a common autoimmune disease caused by pathogenic antiphospholipid antibodies, leading to recurrent thrombosis and/or obstetrical complications. Importantly for nephrologists, antiphospholipid antibodies are associated with various renal manifestations including large renal vessel thrombosis, renal artery stenosis, and a constellation of intrarenal lesions that has been termed antiphospholipid nephropathy. This last condition associates various degrees of acute thrombotic microangiopathy, proliferative and fibrotic lesions of the intrarenal vessels, and ischemic modifications of the renal parenchyma. The course of the disease can range from indolent nephropathy to devastating acute renal failure. The pejorative impact of antiphospholipid antibody-related renal complication is well established in the context of systemic lupus erythematous or after renal transplantation. In contrast, the exact significance of isolated antiphospholipid nephropathy remains uncertain. The evidence to guide management of the renal complications of antiphospholipid syndrome is limited. However, the recent recognition of the heterogeneous molecular mechanisms underlying the progression of intrarenal vascular lesions in antiphospholipid syndrome have opened promising tracks for patient monitoring and targeted therapeutic intervention.

Nonthrombotic proliferative vasculopathy associated with antiphospholipid antibodies: A case report and literature review

A 20-year-old man presented with recurrent hemoptysis for seven months. A small subpleural nodule in his right lower lobe was found and excised surgically. Based on the presence of antiphospholipid antibodies (aPL) and vascular wall hypertrophy without vasculitis or an intraluminal thrombus, nonthrombotic proliferative vasculopathy (NTPV) affecting pulmonary arteries was diagnosed. Recently, aPL have been postulated to directly induce the proliferation of vascular cells in the intima and media, leading to NTPV. We review 5 cases of NTPV-associated aPL with critical ischemia in the lower extremities and gastrointestinal infarction. NTPV-associated aPL might be distinct from classic antiphospholipid syndrome and should be considered in aPL-positive patients who present with vascular occlusions of medium-sized vessels in the absence of atherosclerotic risk factors and systemic or local inflammation.

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.

IgG/IgM antiphospholipid antibodies present in the classification criteria for the antiphospholipid syndrome: a critical review of their association with thrombosis

Essentials The clinical value of IgM antibodies in thrombotic antiphospholipid syndrome (APS) is debated. By review of literature, we reconsidered the clinical value of IgM antibodies in thrombotic APS. More significant correlations with thrombosis were found for the IgG compared to IgM isotype. Unavailability of paired IgG/IgM results hampers evaluating the added value of IgM positivity. Click to hear Dr de Groot's perspective on antiphospholipid syndrome

SUMMARY

Background Despite the update of the classification criteria for the antiphospholipid syndrome (APS), difficulties persist in the identification of patients at risk for thrombosis. Current guidelines include assays detecting IgG/IgM anti-β2 -glycoprotein I and anti-cardiolipin antibodies, although the relevance of IgM antibodies has been debated. Objectives Through a review of the literature from 2001 to 2014, we aimed to formally establish the thrombotic risk stratification potential of IgM as compared with IgG anti-phospholipid antibodies (aPLs). Patients/methods One thousand two hundred and twenty-eight articles were selected by a computer-assisted search of the literature. Of the 177 studies that met our inclusion criteria, the clinical value of IgG/IgM aPLs was established through analysis of odds ratios for thrombosis or percentage of positives in the thrombotic population. Results/conclusions We clearly found more significant correlations with thrombosis for the IgG than for the IgM isotype. Nonetheless, in a minority of studies, significant associations with thrombosis were found for IgM but not IgG antibodies. The unavailability of paired results of IgG and IgM for each separate patient hampers evaluation of the added value of isolated IgM positivity. To fully take advantage of results obtained by future studies, we strongly encourage scientists to provide all studied information per patient. We planned a large multicenter study to investigate clinical associations of isolated/combined positivity for criteria/non-criteria aPLs. Importantly, because of the presence of non-pathogenic aPLs, quantitative assays are characterized by a high false-positivity rate. Optimization of functional assays, such as thrombin generation measuring the whole scheme of coagulation, may help to reduce APS-related morbidity and mortality.

Antiphospholipid Syndrome and Kidney Involvement: New Insights

Antiphospholipid syndrome is an autoimmune disorder characterized by vascular thromboses and pregnancy morbidity associated with antiphospholipid antibodies: lupus anticoagulant, IgG or IgM anticardiolipin or anti-beta 2-glycoprotein I. The kidney is one of the major target organs in antiphospholipid syndrome (APS). However, beyond the known involvement of the kidney in primary and associated APS, we may be observing a new form of APS within the context of renal failure. This review describes the classical kidney manifestations of APS and provides new considerations to be taken into account.

The clinical significance of antiphospholipid antibodies in systemic lupus erythematosus

Antiphospholipid syndrome (APS) is the association of thrombosis and/or pregnancy morbidity with antiphospholipid antibodies (aPL). Thirty to forty percent of systemic lupus erythematosus (SLE) patients are tested positive for aPL, which may have an impact on the SLE presentation, management, and prognosis. Compared with SLE patients without aPL, those with aPL have a higher prevalence of thrombosis, pregnancy morbidity, valve disease, pulmonary hypertension, livedo reticularis, thrombocytopenia, hemolytic anemia, acute/chronic renal vascular lesions, and moderate/severe cognitive impairment; worse quality of life; and higher risk of organ damage. The use of low-dose aspirin (LDA) is controversial for primary thrombosis and pregnancy morbidity prevention because of the lack of strong prospective controlled data. Similarly, the use of anticoagulation is controversial for patients with an aPL-related nephropathy. Until further studies are available, physicians should discuss the risk/benefits of LDA or anticoagulation as well as the available literature with patients.

Antiphospholipid syndrome, antiphospholipid antibodies and solid organ transplantation

Antiphospholipid syndrome is considered a high risk factor for any kind of surgery. Considering that all solid organ transplants are critically dependent on the patency of vascular anastomosis, there is much concern about the consequences this pro-thrombotic condition may have on transplantation. Relatively little information is available in the literature assessing the real risk that antiphospholipid syndrome or the presence of antiphospholipid antibodies represent in solid organ transplantation. The aim of this article is to review the literature related to transplantation of solid organs in patients diagnosed with antiphospholipid syndrome or patients with positive antiphospholipid antibodies.

Outcome of patients with systemic lupus erythematosus on chronic dialysis: an observational study of incident patients of the French National Registry 2002–2012

Objectives

The objective of this article is to describe the outcome (mortality, kidney transplantation) of patients with systemic lupus erythematosus (SLE) on chronic dialysis.

Methods

The overall and cardiovascular (CV) mortality and access to kidney transplantation were studied in all SLE patients incident on chronic dialysis in France between 2002 and 2012 (REIN registry). They were compared to age- and sex-matched patients with diabetic nephropathy and with autosomal dominant polycystic kidney disease (PKD) on chronic dialysis.

Results

A total of 368 SLE patients were included in the national REIN registry between 2002 and 2012. Cumulative incidence of death was 16.9% at five years, with no difference between haemodialysis and peritoneal dialysis. Independent risk factors of death were age, past history of cardiovascular disease (CVD) and chronic respiratory insufficiency. At five years, CV and all-cause mortality in SLE patients were lower than in matched diabetic patients, but three-fold higher than in matched PKD patients. Access to the kidney transplant waiting list and to kidney transplantation was higher in SLE patients than in matched diabetic patients, but lower than in matched PKD patients.

Conclusions

SLE patients on chronic dialysis are a population at high risk of death influenced by CV burden and chronic respiratory failure, but not by the method of dialysis. Their outcome, in terms of mortality and access to kidney transplantation, is intermediate between diabetic patients and patients with PKD.

Antiphospholipid syndrome in renal transplantation

Antiphospholipid syndrome (APS) may occur in isolation or in association with systemic lupus erythematosus (SLE), with the potential to cause renal failure via several distinct pathologies. Renal transplantation in the presence of APS carries a risk of early graft loss from arterial or venous thrombosis, or thrombotic microangiopathy (TMA). Whilst perioperative anticoagulation reduces the risk of large vessel thrombosis, it may result in significant haemorrhage, and its efficacy in preventing post-transplant TMA is uncertain. Here, we report a patient with end-stage kidney disease (ESKD) due to lupus nephritis and APS, in whom allograft TMA developed soon after transplantation despite partial anticoagulation. TMA resolved with plasma exchange-based therapy albeit with some irreversible graft damage and renal impairment. We discuss the differential diagnosis of post-transplant TMA, and current treatment options.

Plasmapheresis in a patient with antiphospholipid syndrome before living-donor kidney transplantation: a case report

Background

Early graft thrombosis and bleeding complications remain important causes of early graft loss following kidney transplantation in patients with antiphospholipid syndrome. Anti-β2-glycoprotein I IgG is a disease-specific antibody in patients with antiphospholipid syndrome. Although plasmapheresis is partially effective for antibody removal, the optimal treatment allowing successful transplantation in patients with antiphospholipid syndrome has not been established. This is the first report of a patient with antiphospholipid syndrome who successfully underwent living-donor kidney transplantation following prophylactic plasmapheresis for removal of anti-β2-glycoprotein I IgG.

Case presentation

A 37-year-old Japanese female was scheduled to undergo a living-donor kidney transplant from her mother. At age 25 years, she experienced renal vein thrombosis, was diagnosed with antiphospholipid syndrome secondary to systemic lupus erythematosus, and was subsequently treated with prednisolone and warfarin. At age 37 years, she was diagnosed with end stage kidney disease, requiring maintenance hemodialysis because of recurrent renal vein thrombosis despite taking anticoagulation therapy. The pretreatment protocol consisted of prophylactic plasmapheresis plus full anticoagulation therapy to counteract the risks of early graft thrombosis. Anticardiolipin and anti-β2-glycoprotein I IgGs were successfully removed by both double filtration plasmapheresis and plasma exchange. The allograft kidney began to function soon after transplantation. No obvious thrombotic complications were observed after transplantation, although anti-β2-glycoprotein I IgG increased to the level observed before plasmapheresis. One year after transplantation, the patient’s kidney function remains stable while receiving anticoagulation therapy as well as a maintenance immunosuppressive regimen.

Conclusion

Prophylactic plasmapheresis plus full anticoagulation therapy may be an effective strategy in patients with antiphospholipid syndrome undergoing living-donor kidney transplantation.

Inhibition of the mTORC pathway in the antiphospholipid syndrome

BACKGROUND

Although thrombosis is considered the cardinal feature of the antiphospholipid syndrome, chronic vascular lesions are common, particularly in patients with life-threatening complications. In patients who require transplantation, vascular lesions often recur. The molecular pathways involved in the vasculopathy of the antiphospholipid syndrome are unknown, and adequate therapies are lacking.

METHODS

We used double immunostaining to evaluate pathway activation in the mammalian target of rapamycin complex (mTORC) and the nature of cell proliferation in the vessels of patients with primary or secondary antiphospholipid syndrome nephropathy. We also evaluated autopsy specimens from persons who had catastrophic antiphospholipid syndrome. The molecular pathways through which antiphospholipid antibodies modulate the mTORC pathway were evaluated in vitro, and potential pharmacologic inhibitors were also tested in vitro. Finally, we studied the effect of sirolimus in kidney-transplant recipients with the antiphospholipid syndrome.

RESULTS

The vascular endothelium of proliferating intrarenal vessels from patients with antiphospholipid syndrome nephropathy showed indications of activation of the mTORC pathway. In cultured vascular endothelial cells, IgG antibodies from patients with the antiphospholipid syndrome stimulated mTORC through the phosphatidylinositol 3-kinase (PI3K)-AKT pathway. Patients with antiphospholipid syndrome nephropathy who required transplantation and were receiving sirolimus had no recurrence of vascular lesions and had decreased vascular proliferation on biopsy as compared with patients with antiphospholipid antibodies who were not receiving sirolimus. Among 10 patients treated with sirolimus, 7 (70%) had a functioning renal allograft 144 months after transplantation versus 3 of 27 untreated patients (11%). Activation of mTORC was also found in the vessels of autopsy specimens from patients with catastrophic antiphospholipid syndrome.

CONCLUSIONS

Our results suggest that the mTORC pathway is involved in the vascular lesions associated with the antiphospholipid syndrome. (Funded by INSERM and others.).

Thrombotic microangiopathy in renal allografts: the diagnostic challenge

PURPOSE OF REVIEW

The diagnosis of thrombotic microangiopathy (TMA) is complex and often difficult. This review provides an approach to the diagnosis with emphasis on recent relevant developments.

RECENT FINDINGS

There is increasing evidence that most cases of recurrent TMA in renal allografts are secondary to mutations in genes encoding complement regulatory factors and complement components, such as factor H, factor I, membrane cofactor protein, C3, and others. Genetic work-up for these potential complement abnormalities is now available and recommended. Another important cause for recurrent TMA is the presence of autoantibodies, such as antibodies to factor H and antiphospholipid antibodies. De-novo TMA is much more common than recurrent TMA in renal allografts. De-novo TMA can be secondary to calcineurin inhibitor treatment, mammalian target of rapamycin inhibitor treatment, but frequently also to antibody-mediated rejection and less commonly to infections. Systemic signs of TMA are often absent, and the gold standard for diagnosis is the renal allograft biopsy. Unfortunately, diagnostic criteria for TMA are somewhat subjective, and the biopsy provides limited information regarding the exact underlying cause.

SUMMARY

TMA is a serious complication of renal transplantation, usually with poor outcome. However, with improving understanding of underlying pathogeneses, more effective disease-specific therapeutic interventions can be designed. Appropriate treatment depends on the correct diagnosis, which relies primarily on renal allograft biopsy. Standardization of pathologic criteria and introduction of new molecular testing methods in renal biopsy specimens hopefully will improve diagnostic accuracy.

Renal transplantation in systemic lupus erythematosus: outcome and prognostic factors in 50 cases from a single centre

BACKGROUND

End-stage renal disease (ESRD) is an important cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE).

OBJECTIVES

To analyze the outcome and prognostic factors of renal transplantation in patients with ESRD due to SLE from January 1986 to December 2013 in a single center.

RESULTS

Fifty renal transplantations were performed in 40 SLE patients (32 female (80%), mean age at transplantation 36±10.4 years). The most frequent lupus nephropathy was type IV (72.2%). Graft failure occurred in a total of 15 (30%) transplantations and the causes of graft failure were chronic allograft nephropathy (n=12), acute rejection (n=2), and chronic humoral rejection (1). The death-censored graft survival rates were 93.9% at 1 year, 81.5% at 5 years, and 67.6% at the end of study. The presence of deceased donor allograft (P=0.007) and positive anti-HCV antibodies (P=0.001) negatively influence the survival of the renal transplant. The patient survival rate was 91.4% at the end of the study. Recurrence of lupus nephritis in renal allograft was observed in one patient.

CONCLUSION

Renal transplantation is a good alternative for renal replacement therapy in patients with SLE. In our cohort, the presence of anti-HCV antibodies and the type of donor source were related to the development of graft failure.

Renal involvement in antiphospholipid syndrome

Antiphospholipid syndrome (APS) is an autoimmune disease defined by the presence of arterial or venous thrombotic events and/or pregnancy morbidity in patients who test positive for antiphospholipid antibodies (aPLs). APS can be isolated (known as primary APS) or associated with other autoimmune diseases, such as systemic lupus erythematosus (SLE; known as secondary APS). The kidney is a major target organ in APS and renal thrombosis can occur at any level within the vasculature of the kidney (renal arteries, intrarenal arteries, glomerular capillaries and renal veins); events reflect the site and size of the involved vessels. Histological findings vary widely, including ischaemic glomeruli and thrombotic lesions without glomerular or arterial immune deposits on immunofluorescence. Renal prognosis is affected by the presence of aPLs in patients with lupus nephritis and can be poor. In patients with SLE and aPLs, biopsy should be performed because inflammatory and thrombotic lesions require different therapeutic approaches. Renal involvement in patients with definite APS is treated by anticoagulation with long-term warfarin. The range of renal manifestations associated with APS is broadening and, therefore, aPLs have increasing relevance in end-stage renal disease, transplantation and pregnancy.

Eculizumab prevents recurrent antiphospholipid antibody syndrome and enables successful renal transplantation

Renal transplantation in patients with antiphospholipid antibodies has historically proven challenging due to increased risk for thrombosis and allograft failure. This is especially true for patients with antiphospholipid antibody syndrome (APS) and its rare subtype, the catastrophic antiphospholipid antibody syndrome (CAPS). Since a critical mechanism of thrombosis in APS/CAPS is one mediated by complement activation, we hypothesized that preemptive treatment with the terminal complement inhibitor, eculizumab, would reduce the extent of vascular injury and thrombosis, enabling renal transplantation for patients in whom it would otherwise be contraindicated. Three patients with APS, two with a history of CAPS, were treated with continuous systemic anticoagulation together with eculizumab prior to and following live donor renal transplantation. Two patients were also sensitized to human leukocyte antigens (HLA) and required plasmapheresis for reduction of donor-specific antibodies. After follow-up ranging from 4 months to 4 years, all patients have functioning renal allografts. No systemic thrombotic events or early graft losses were observed. While the appropriate duration of treatment remains to be determined, this case series suggests that complement inhibitors such as eculizumab may prove to be effective in preventing the recurrence of APS after renal transplantation.

[Antiphospholipid syndrome in nephrology. Kidney damage and practical aspects of the management]

The antiphospholipid syndrome is a thrombophilia characterized by the combination of arterial and/or venous thrombotic events or obstetric clinical events, associated with persistent presence of antiphospholipid antibodies. In this syndrome, thromboses may affect all of the vascular tree, renal damage is frequently associated with a specific antiphospholipid syndrome nephropathy. We propose in this review to provide updated recommendations on the management of antiphospholipid syndrome in nephrology. Treatment is based on long-term anticoagulant therapy with or without antiplatelet agents according to clinical events. The use of a conventional nephroprotection must not be forgotten (strict control of blood pressure with drugs blocking the renin-angiotensin-aldosterone system). Catastrophic antiphospholipid syndrome is an extremely severe complication which can threaten the vital prognosis of the patient. This justifies particular surveillance, as well as prevention in high-risk situations. We also illustrate the difficulties of long-term management in these patients, both in dialysis or kidney transplantation.

Physiological and therapeutic complement regulators in kidney transplantation

PURPOSE OF REVIEW

This review will summarize the key contribution of complement regulators in the immune response to an allograft.

RECENT FINDINGS

Over the past 10 years, compelling evidences have been accumulated in support of a critical role of complement in the pathological phenomena related to organ transplantation. In addition to recurrence of complement-mediated disease after graft, complement is involved in situations as diverse as brain death induced tissue damages, ischaemia-reperfusion and antibody-mediated rejections. This complement activation is counterbalanced by various regulatory mechanisms.

SUMMARY

We discuss the role of physiological and therapeutic complement regulators that are designed to overcome the impact of complement overactivation with the aim of improving long-term transplant outcomes. We will focus primarily on renal allograft, but the discussed mechanisms take place to a different degree in any kind of organ transplantation.

Improving outcomes in patients with lupus and end-stage renal disease

The development of lupus-related end-stage renal disease (ESRD) confers the highest mortality rates among individuals with lupus. Lupus-related ESRD is also associated with higher morbidity and mortality rates compared with non-lupus ESRD. We review the evidence that persistent lupus activity, hypercoagulability, and continuing immunosuppression may contribute to unfavorable outcomes in dialysis and renal transplantation among lupus patients. Robust epidemiologic studies are needed to develop individualized evidence-based approaches to treating lupus-related ESRD. In the meantime, managing lupus-related ESRD presents a significant challenge for clinicians and requires a team approach involving nephrologists and rheumatologists. Goals of therapy after developing ESRD should include continuing monitoring of lupus activity, minimizing corticosteroid exposure, and choosing the most appropriate renal replacement therapy based on patient's risk profile and quality-of-life considerations.

Recurrence of glomerulonephritis after renal transplantation

Recurrence of glomerulonephritis following renal transplantation is considered an important cause of allograft failure. The incidence of recurrence of glomerulonephritis varies widely depending on the definition of recurrence (pathologic recurrence or clinicopathologic recurrence) and the original glomerular disease. Moreover the impact of recurrence of glomerular disease on allograft outcome varies widely between different forms of glomerulonephritis. Whereas IgA nephritis recurs in up to one third of transplanted patients, this is not associated with adverse effects on graft survival. In contrast, recurrent focal segmental glomerulosclerosis and membranoproliferative glomerulopathy have an unfavorable prognosis. Overall, long-term graft survival in patients transplanted for glomerulonephritis is comparable to survival in patients with other causes of ESRD. In recent years, several mechanisms for recurrent disease after transplantation (e.g. PLA2R antibodies in membranous nephropathy and suPAR in FSGS) have been identified, and these findings have helped to elucidate the pathogenesis of glomerular diseases. Although renal transplantation is the treatment of choice for end-stage renal disease as a consequence of glomerulonephritis, further studies are required to develop optimal strategies to prevent, diagnose and treat recurrent glomerular diseases.

Targeted strategies in the prevention and management of atypical HUS recurrence after kidney transplantation

Atypical hemolytic and uremic syndrome (aHUS) is associated with a high rate of recurrence and poor outcomes after kidney transplantation. Fortunately, recent advances in the understanding of the pathogenesis of aHUS have permitted an individualized risk assessment of post-transplant recurrence. Acquired or inherited dysregulation of the alternative complement pathway, thought to be the driving force of the disease, is identified in most aHUS patients. Notably, depending on the mutations involved, the risk of recurrence greatly varies, highlighting the importance of undertaking etiological investigations prior to kidney transplantation. In those with moderate to high risk of recurrence, the use of a prophylactic therapy, consisting in either plasmapheresis or eculizumab therapies, represents a major stride forward in the prevention of aHUS recurrence after kidney transplantation. In those who experience aHUS recurrence, a growing number of observations suggest that eculizumab therapy outperforms curative plasma therapy. The optimal duration of both prophylactic and curative therapies remains an important, yet unaddressed, issue. In this respect, the kidney transplant recipients, continuously exposed to endothelial-insulting factors, referred here as to triggers, might have a sustained high risk of recurrence. A global therapeutic approach should thus attempt to reduce exposure to these triggers.

Eculizumab improves posttransplant thrombotic microangiopathy due to antiphospholipid syndrome recurrence but fails to prevent chronic vascular changes

Thrombotic microangiopathy (TMA) is one of the hallmark vascular lesions of antiphospholipid syndrome nephropathy (APSN). These lesions are at high risk of recurrence after kidney transplantation. The complement pathway is thought to be active in this process. We used eculizumab to treat three consecutive kidney transplant recipients with posttransplant TMA due to APSN recurrence that was resistant to plasmapheresis and explored the complement deposition and apoptotic and vascular cell markers on the sequential transplant biopsies. Treatment with eculizumab resulted in a rapid and dramatic improvement of the graft function in all three patients and in improvement of the TMA lesions within the graft. None of these patients had TMA flares after eculizumab was withdrawn. At the time of TMA diagnosis, immunofluorescence studies revealed intense C5b-9 and C4d depositions at the endothelial cell surface of the injured vessels. Moreover, C5b-9 colocalized with vessels exhibiting a high rate of apoptotic cells. Examination of sequential biopsies during eculizumab therapy showed that TMA lesions, C4d and apoptotic markers were rapidly cleared but the C5b-9 deposits persisted for several months as a footprint of the TMA. Finally, we noticed that complement inhibition did not prevent the development of the chronic vascular changes associated with APSN. Eculizumab seems to be an efficient method for treating severe forms of posttransplant TMA due to APSN recurrence. Terminal complement inhibition does not prevent the development of chronic APSN.