Prevalence of hepatitis C in patients with idiopathic glomerulopathies in native and transplant kidneys

Glomerular Disease in Liver Disease

Glomerular diseases are an important cause of kidney disease in patients with liver disease. Although kidney involvement due to tubular or vascular disease is more common, glomerular diseases became more prevalent as hepatitis infections increased and then subsequently decreased with the widespread availability of hepatitis A and B vaccines and the development of effective antiviral treatments for hepatitis B and C. In this review, we discuss the common glomerular pathologies that are seen in patients with liver disease and the current treatment options available to them.

Transplant Glomerulopathy: Importance of Ultrastructural Examination

Background

Transplant glomerulopathy (TG) is a morphologic alteration in glomeruli of renal allografts, characterized by glomerular basement membrane reduplications.

Summary

TG is associated with progressive chronic allograft dysfunction and proteinuria and is a diagnostic feature of chronic antibody-mediated rejection (ABMR) in patients positive for donor-specific antibodies, according to the Banff schema for renal allograft pathology. It is a definitive endpoint in clinical trials and interventional studies for ABMR, but the lesion can also occur in the absence of definitive alloimmune injury, as a consequence of chronic thrombotic microangiopathy, and in some cases in association with hepatitis C infection. This review discusses the pathophysiology and clinical presentation of TG, the diagnostic features by light microscopy, and focuses on the sequential ultrastructural stages of the lesion. The differential diagnosis of TG, and Banff grading of the lesion, are reviewed. Clinicopathological indications for performing routine ultrastructural examination of renal allograft biopsies are discussed.

Key Messages

TG can be diagnosed at an early stage by electron microscopy, before histological features are apparent, emphasizing the importance of ultrastructural examination of renal allograft biopsies for an early diagnosis, when therapeutic intervention may be beneficial.

Mechanisms of kidney dysfunction in the cirrhotic patient: Non-hepatorenal acute-on-chronic kidney damage considerations

Renal dysfunction is a common finding in cirrhotic patients and has a great physiologic, and therefore, prognostic relevance. The combination of liver disease and renal dysfunction can occur as a result of systemic conditions that affect both the liver and the kidney, although primary disorders of the liver complicated by renal dysfunction are much more common. As most of the renal dysfunction scenarios in cirrhotic patients correspond to either prerenal azotemia or hepatorenal syndrome (HRS), physicians tend to conceive renal dysfunction in cirrhotic patients as mainly HRS. However, there are many systemic conditions that may cause both a "baseline" chronic kidney damage and a superimposed kidney dysfunction when this systemic condition worsens. The main aim of this article is to review some of the most important non prerenal non-HRS considerations regarding acute on chronic kidney dysfunction in cirrhotic patients, including renal manifestation of related to non-alcoholic steatohepatitis (NASH) viral hepatitis, the effect of cardiorenal syndrome in cirrhotics and corticosteroid-deficiency associated renal dysfunction.

Diagnosis and management of renal dysfunction in patients with cirrhosis

Introduction: Renal dysfunction commonly occurs in patients with cirrhosis and is typically associated with poor prognosis. Several pathophysiologic mechanisms are responsible for renal disease in these patients, prompt identification permits individualized management.Areas covered: Pathophysiology, evaluation and differential diagnosis, management and prognosis of renal disease in patients with cirrhosis. Special focus on management of hepatorenal syndrome and indications for simultaneous liver-kidney transplantation.Literature search methodology: a detailed literature search was performed using PubMed without date restrictions. Published guidelines and position papers were also used and cross-referenced to identify additional studies.Expert opinion: The prognostic significance of renal dysfunction in patients with cirrhosis is highlighted by the inclusion of serum creatinine in the model for end-stage liver disease (MELD). Both acute and chronic renal dysfunction result in increased mortality in patients with cirrhosis, although there are marked differences related to the etiology of renal disease. Early recognition and prompt intervention determined by the most likely etiology are key in the management of these patients. Simultaneous liver-kidney transplantation improves patient survival compared to isolated liver transplantation in patients with cirrhosis and persistent renal impairment; however, selection of candidates must be judicious and individualized due to the ongoing shortage of donor kidneys.

Management and treatment of the HCV-infected kidney transplant patient

The prevalence of hepatitis C virus infection is increased in patients with end stage kidney disease compared to the general population and is an adverse outcome determinant. Direct-acting antiviral therapy for hepatitis C virus is changing the management paradigm of infected kidney transplant candidates and recipients, with potential to reduce patient morbidity and mortality. This review describes the hepatic and nonhepatic manifestations of hepatitis C virus in kidney transplant patients as well as management and treatment strategies to optimize transplant outcomes, highlighting the importance of direct-acting antivirals in this population.

Management of hepatitis C virus infection in patients with chronic kidney disease: position statement of the joint committee of Italian association for the study of the liver (AISF), Italian society of internal medicine (SIMI), Italian society of infectious and tropical disease (SIMIT) and Italian society of nephrology (SIN)

Hepatitis C virus (HCV) infection is now considered a systemic disease due to the occurrence of extra-hepatic manifestations. Among these, the renal involvement is frequent. HCV infection, in fact, is strongly associated with proteinuria and chronic kidney disease (CKD) and negatively affects the prognosis of renal patients. In the last few years, availability of more specific and effective drugs against HCV has dramatically changed the clinical course of this disease. These drugs may provide further advantages in the CKD population as a whole by reducing progression of renal disease, mortality rate and by increasing the survival of graft in renal transplant recipients. The strict pathogenetic and prognostic link between HCV infection and CKD requires an ongoing relationship among the healthcare professionals involved in the treatment of both HCV infection and CKD. Therefore, Scientific Societies involved in the care of this high-risk population in Italy have organized a joint expert panel. The aim of the panel is to produce a position statement that can be used in daily clinical practice for the management of HCV infected patients across the whole spectrum of renal disease, from the conservative phase to renal replacement treatments (dialysis and transplantation). Sharing specific evidence-based expertise of different professional healthcare is the first step to obtain a common ground of knowledge on which to instate a model for multidisciplinary management of this high-risk population. Statements cover seven areas including epidemiology of CKD, HCV-induced glomerular damage, HCV-related renal risk, staging of liver disease in patients with CKD, prevention of transmission of HCV in hemodialysis units, treatment of HCV infection and management of HCV in kidney transplantation.

The association of hepatitis C infection with the onset of CKD and progression into ESRD

Hepatitis C virus (HCV) infection is not only an important cause of chronic liver disease, but extrahepatic manifestations are common and include chronic kidney disease (CKD). HCV is classically associated with cryoglobulinemic glomerulonephritis in the context of mixed cryoglobulinemia syndrome, but other glomerular diseases also occur and may be significantly under-recognized. HCV may cause glomerular disease by immune complex deposition; however, other potential mechanisms by which HCV promotes CKD include a direct cytopathic effect of the virus on renal tissue, and by its association with accelerated atherosclerosis, insulin resistance, and chronic inflammation. Epidemiologic studies show HCV infection confers an increased risk of incident CKD and accelerates progression of CKD to end-stage renal disease (ESRD) in the general population, as well as subpopulations including diabetic patients, those coinfected with human immunodeficiency virus (HIV), and kidney transplant recipients. Patients with CKD and HCV infection experience inferior clinical outcomes, including poorer quality of life and an increased risk of mortality. Treatment with interferon-based regimens is associated with decreased risk of incident CKD and ESRD, though prior studies are limited by the small number of patients with HCV and CKD who underwent treatment. With the advent of new, well-tolerated direct-acting antiviral combinations that are not cleared by the kidneys, it is possible to treat all genotypes of HCV infection in patients with CKD and ESRD. More data on the effect of direct-acting antivirals on CKD incidence and progression are necessary. However, there is every expectation that with improved access to HCV treatment, the burden of CKD in patients with HCV could significantly decline.

Long-term Patient and Graft Survival of Kidney Transplant Recipients With Hepatitis C Virus Infection in the United States

BACKGROUND

Hepatitis C virus (HCV) infection is common among kidney transplant (KTx) recipients. However, the impact of HCV infection on long-term graft and recipient survival after KTx from large-scale data remains to be determined.

METHODS

We used the Organ Procurement and Transplantation Network database to identify all adults undergoing KTx in 2004 to 2006 in the United States. A propensity score was created to match each HCV-positive recipient with an HCV-negative control for unbiased comparisons. Survival analysis was conducted to evaluate recipient and death-censored graft survival.

RESULTS

Out of 33 357 adult primary KTx recipients, 1470 (4.4%) were HCV-positive: 1364 HCV-positive and -negative pairs were selected by propensity score matching. Based on multivariable regression models, HCV is associated with a higher risk of death (hazard ratio [HR], 1.50; 95% confidence interval [95% CI], 1.28-1.75) and graft failure (HR, 1.26; 95% CI, 1.08-1.47). Infection was a more common cause of death in HCV-positive patients than in HCV-negative recipients (HR, 1.64; 95% CI, 1.12-2.42). The incidence of death due to liver failure was 0.23% per year among HCV-positive recipients, whereas no HCV-negative recipients died from liver failure. Graft failure due to recurrent disease was higher in HCV-positive than in HCV-negative recipients (HR, 2.00; 95% CI, 1.06-3.78).

CONCLUSION

HCV infection is associated with decreased long-term recipient and graft survival. Future studies are needed to examine whether recently available, safe, and effective antiviral therapy improves the long-term clinical outcome in these patients.

Management of hepatitis C virus infection in patients with chronic kidney disease: position statement of the joint committee of Italian association for the study of the liver (AISF), Italian society of internal medicine (SIMI), Italian society of infectious and tropical disease (SIMIT) and Italian society of nephrology (SIN)

Hepatitis C virus (HCV) infection is now considered a systemic disease due to the occurrence of extra-hepatic manifestations. Among these, the renal involvement is frequent. HCV infection, in fact, is strongly associated with proteinuria and chronic kidney disease (CKD) and negatively affects the prognosis of renal patients. In the last few years, availability of more specific and effective drugs against HCV has dramatically changed the clinical course of this disease. These drugs may provide further advantages in the CKD population as a whole by reducing progression of renal disease, mortality rate and by increasing the survival of graft in renal transplant recipients. The strict pathogenetic and prognostic link between HCV infection and CKD requires an ongoing relationship among the healthcare professionals involved in the treatment of both HCV infection and CKD. Therefore, Scientific Societies involved in the care of this high-risk population in Italy have organized a joint expert panel. The aim of the panel is to produce a position statement that can be used in daily clinical practice for the management of HCV infected patients across the whole spectrum of renal disease, from the conservative phase to renal replacement treatments (dialysis and transplantation). Sharing specific evidence-based expertise of different professional healthcare is the first step to obtain a common ground of knowledge on which to instate a model for multidisciplinary management of this high-risk population. Statements cover seven areas including epidemiology of CKD, HCV-induced glomerular damage, HCV-related renal risk, staging of liver disease in patients with CKD, prevention of transmission of HCV in hemodialysis units, treatment of HCV infection and management of HCV in kidney transplantation.

Management of hepatitis C virus infection in patients with chronic kidney disease: position statement of the joint committee of Italian association for the study of the liver (AISF), Italian society of internal medicine (SIMI), Italian society of infectious and tropical disease (SIMIT) and Italian society of nephrology (SIN)

Hepatitis C virus (HCV) infection is now considered a systemic disease due to the occurrence of extra-hepatic manifestations. Among these, the renal involvement is frequent. HCV infection, in fact, is strongly associated with proteinuria and chronic kidney disease (CKD) and negatively affects the prognosis of renal patients. In the last few years, availability of more specific and effective drugs against HCV has dramatically changed the clinical course of this disease. These drugs may provide further advantages in the CKD population as a whole by reducing progression of renal disease, mortality rate and by increasing the survival of graft in renal transplant recipients. The strict pathogenetic and prognostic link between HCV infection and CKD requires an ongoing relationship among the healthcare professionals involved in the treatment of both HCV infection and CKD. Therefore, Scientific Societies involved in the care of this high-risk population in Italy have organized a joint expert panel. The aim of the panel is to produce a position statement that can be used in daily clinical practice for the management of HCV infected patients across the whole spectrum of renal disease, from the conservative phase to renal replacement treatments (dialysis and transplantation). Sharing specific evidence-based expertise of different professional healthcare is the first step to obtain a common ground of knowledge on which to instate a model for multidisciplinary management of this high-risk population. Statements cover seven areas including epidemiology of CKD, HCV-induced glomerular damage, HCV-related renal risk, staging of liver disease in patients with CKD, prevention of transmission of HCV in hemodialysis units, treatment of HCV infection and management of HCV in kidney transplantation.

Management of hepatitis C virus infection in patients with chronic kidney disease: position statement of the joint committee of Italian association for the study of the liver (AISF), Italian society of internal medicine (SIMI), Italian society of infectious and tropical disease (SIMIT) and Italian society of nephrology (SIN)

Hepatitis C virus (HCV) infection is now considered a systemic disease due to the occurrence of extra-hepatic manifestations. Among these, the renal involvement is frequent. HCV infection, in fact, is strongly associated with proteinuria and chronic kidney disease (CKD) and negatively affects the prognosis of renal patients. In the last few years, availability of more specific and effective drugs against HCV has dramatically changed the clinical course of this disease. These drugs may provide further advantages in the CKD population as a whole by reducing progression of renal disease, mortality rate and by increasing the survival of graft in renal transplant recipients. The strict pathogenetic and prognostic link between HCV infection and CKD requires an ongoing relationship among the healthcare professionals involved in the treatment of both HCV infection and CKD. Therefore, Scientific Societies involved in the care of this high-risk population in Italy have organized a joint expert panel. The aim of the panel is to produce a position statement that can be used in daily clinical practice for the management of HCV infected patients across the whole spectrum of renal disease, from the conservative phase to renal replacement treatments (dialysis and transplantation). Sharing specific evidence-based expertise of different professional healthcare is the first step to obtain a common ground of knowledge on which to instate a model for multidisciplinary management of this high-risk population. Statements cover seven areas including epidemiology of CKD, HCV-induced glomerular damage, HCV-related renal risk, staging of liver disease in patients with CKD, prevention of transmission of HCV in hemodialysis units, treatment of HCV infection and management of HCV in kidney transplantation.

Impact of anti-HCV direct antiviral agents on graft function and immunosuppressive drug levels in kidney transplant recipients: a call to attention in the mid-term follow-up in a single-center cohort study

The medium-term impact on graft function and immunosuppressive drug pharmacokinetics of direct antiviral agents (DAAs) among hepatitis C virus (HCV)-infected kidney transplant (KT) recipients remain unclear. We compared pre- and post-treatment 12-month trajectories of estimated glomerular filtration rate (ΔeGFR) and 24-h proteinuria (Δ24-h proteinuria) in 49 recipients treated with DAAs (mostly sofosbuvir plus ledipasvir). Among evaluable patients, 66.7% and 100.0% had undetectable viral load by week 4 and end of therapy (EoT). The sustained virologic response rate at 12 weeks was 95.8%. Overall, 80.6% of patients receiving tacrolimus required dose escalation while on DAA-based therapy (median increase of 66.7%) to maintain target levels. Tacrolimus levels resulted to be higher at 12 months compared to EoT (7.8 ± 2.1 vs. 6.7 ± 2.0 ng/ml; P-value = 0.002). No changes in graft function during the course of therapy were observed. However, eGFR significantly decreased (P-value <0.001) throughout the first 12 months after EoT. Median ΔeGFR and Δ24-h over pre- and post-treatment periods were 3.9% and -6.1% (P-value = 0.002) and -5.3% and 26.2% (P-value = 0.057). Caution should be exercised when adjusting immunosuppression in HCV-infected KT recipients upon initiation of DAAs, followed by mid-term monitoring of immunosuppressive drug levels and graft function.

Transplant glomerulopathy

In the renal allograft, transplant glomerulopathy represents a morphologic lesion and not a specific diagnosis. The hallmark pathologic feature is glomerular basement membrane reduplication by light microscopy or electron microscopy in the absence of immune complex deposits. Transplant glomerulopathy results from chronic, recurring endothelial cell injury that can be mediated by HLA alloantibodies (donor-specific antibodies), various autoantibodies, cell-mediated immune injury, thrombotic microangiopathy, or chronic hepatitis C. Clinically, transplant glomerulopathy may be silent, detectable on protocol biopsy, or present with overt manifestations, including up to nephrotic range proteinuria, hypertension, and declining glomerular filtration rate. In either case, transplant glomerulopathy is associated with reduced graft survival. This review details the morphologic features of transplant glomerulopathy found on light microscopy, immunofluorescence microscopy, and electron microscopy. The pathophysiology of the causes and risk factors are discussed. Clinical manifestations are emphasized and potential therapeutic modalities are examined.

Tubuloreticular Inclusions in Renal Allografts Associate with Viral Infections and Donor-Specific Antibodies

The presence of tubuloreticular inclusions (TRIs) in native glomerular endothelial cells associates with viral infections and lupus nephritis. However, the associations of TRIs in renal transplant biopsy specimens are not known. We analyzed data from 316 patients who had a transplant biopsy with electron microscopy examination; 41 of 316 (13.0%) patients had TRIs. Patients with TRIs had significantly lower allograft survival rates (50.9%) than patients without TRIs (74.3%; P=0.03). Transplant glomerulopathy-free survival was also inferior in the TRI-positive group (57.5%) compared with the TRI-negative group (87.3%; P=0.002). Serologically, hepatitis C associated with the presence of TRIs (P=0.04) along with donor-specific antibodies (P=0.01). Furthermore, patients who were TRI positive were more likely than patients who were TRI negative to have had a previous rejection episode (P=0.02). On multivariate analysis, TRIs associated with prior rejection, viral infections, and class 1 HLA donor-specific antibodies. These results show that the presence of TRIs in renal allograft biopsy specimens associates with poor allograft outcomes and serologic evidence of viral infections and alloimmunity. The association with alloimmunity is a novel finding that warrants additional investigation.

Hepatitis C virus associated glomerulopathies

Hepatitis C virus (HCV) infection is a systemic disorder which is often associated with a number of extrahepatic manifestations including glomerulopathies. Patients with HCV infection were found to have a higher risk of end-stage renal disease. HCV positivity has also been linked to lower graft and patient survivals after kidney transplantation. Various histological types of renal diseases are reported in association with HCV infection including membranoproliferative glomerulonephritis (MPGN), membranous nephropathy, focal segmental glomerulosclerosis, fibrillary glomerulonephritis, immunotactoid glomerulopathy, IgA nephropathy, renal thrombotic microangiopathy, vasculitic renal involvement and interstitial nephritis. The most common type of HCV associated glomerulopathy is type I MPGN associated with type II mixed cryoglobulinemia. Clinically, typical renal manifestations in HCV-infected patients include proteinuria, microscopic hematuria, hypertension, acute nephritis and nephrotic syndrome. Three approaches may be suggested for the treatment of HCV-associated glomerulopathies and cryoglobulinemic renal disease: (1) antiviral therapy to prevent the further direct damage of HCV on kidneys and synthesis of immune-complexes; (2) B-cell depletion therapy to prevent formation of immune-complexes and cryoglobulins; and (3) nonspecific immunosuppressive therapy targeting inflammatory cells to prevent the synthesis of immune-complexes and to treat cryoglobulin associated vasculitis. In patients with moderate proteinuria and stable renal functions, anti-HCV therapy is advised to be started as pegylated interferon-α plus ribavirin. However in patients with nephrotic-range proteinuria and/or progressive kidney injury and other serious extra-renal manifestations, immunosuppressive therapy with cyclophosphamide, rituximab, steroid pulses and plasmapheresis should be administrated.

Hepatitis C virus infection in nephrology patients

CONTEXT

Hepatitis C virus (HCV) infection leads to chronic liver disease, but also to extra-hepatic manifestations.

EVIDENCE ACQUISITIONS

Directory of Open Access Journals (DOAJ), Google Scholar, Pubmed (NLM), LISTA (EBSCO) and Web of Science have been searched.

RESULTS

Herein, we provide an overview of renal diseases related to HCV and their therapies, as well as the treatment options available for HCV (+)/RNA (+) dialysis patients. We will not mention, however, HCV infection-related complications in the post-kidney transplantation setting.

CONCLUSIONS

Extra-hepatic manifestations of HCV infection include mixed cryoglobulinemia, lymphoproliferative disorders, and renal disease. HCV infection has been reported in association with distinct histological patterns of glomerulonephritis in native kidneys.

The specificity of acute and chronic microvascular alterations in renal allografts

The diagnosis of an antibody-mediated rejection (AMR) is made when there is evident histologic injury in the presence of detectable donor-specific alloantibodies (DSA) and diffuse peritubular capillary C4d staining (C4d-pos). In the presence of only detectable DSA or C4d-pos, the tissue injury is currently considered "presumptive" for antibody causation. In acute antibody-mediated rejection (AAMR), diagnostic morphologic features include microvascular inflammation (MVI), specifically glomerulitis and peritubular capillaritis. In the case of chronic active AMR (CAAMR), these inflammatory lesions have progressed to chronic microvascular injury, transplant glomerulopathy (TG) and peritubular capillary basement membrane multilayering (PTCBMML). Either TG or PTCBMML is sufficient morphological evidence for a diagnosis of CAAMR. Unfortunately, these lesions are not specific. MVI, TG, and PTCBMML are found in the setting of cell-mediated immunity, as well as in association with non-alloimmune mechanisms. The available treatments for AMR and CMR are different, and it is important to ascertain the dominant mechanism when approaching an individual patient. At present, no gold standard exists to establish the specific pathogenesis in the more ambiguous cases. We detail here the differential diagnosis of MVI, TG, and PTCBMML.

Kidney allograft survival after acute rejection, the value of follow-up biopsies

Kidney allografts are frequently lost due to alloimmunity. Still, the impact of early acute rejection (AR) on long-term graft survival is debated. We examined this relationship focusing on graft histology post-AR and assessing specific causes of graft loss. Included are 797 recipients without anti-donor antibodies (DSA) at transplant who had 1 year protocol biopsies. 15.2% of recipients had AR diagnosed by protocol or clinical biopsies. Compared to no-AR, all histologic types of AR led to abnormal histology in 1 and 2 years protocol biopsies, including more fibrosis + inflammation (6.3% vs. 21.9%), moderate/severe fibrosis (7.7% vs. 13.5%) and transplant glomerulopathy (1.4% vs. 8.3%, all p < 0.0001). AR were associated with reduced graft survival (HR = 3.07 (1.92-4.94), p < 0.0001). However, only those AR episodes followed by abnormal histology led to reduced graft survival. Early AR related to more late alloimmune-mediated graft losses, particularly transplant glomerulopathy (31% of losses). Related to this outcome, recipients with AR were more likely to have new DSA class II 1 year posttransplant (no-AR, 11.1%; AR, 21.2%, p = 0.039). In DSA negative recipients, early AR often leads to persistent graft inflammation and increases the risk of new DSA II production. Both of these post-AR events are associated with increased risk of graft loss.

De Novo Fibrillary Glomerulonephritis (FGN) in a Renal Transplant with Chronic Hepatitis C

Chronic hepatitis C viremia (HepC) has been associated with numerous renal manifestations both in native kidneys and in the setting of renal transplantation. Glomerulonephritis (GN) of the renal allograft in the setting of HepC most commonly manifests as type 1 membranoproliferative GN (MPGN), either representing recurrence of the original disease or arising de novo. Other GNs were reported after transplantation in the patient with HepC including membranous nephropathy and thrombotic microangiopathy, as well as an enhanced susceptibility to transplant glomerulopathy. We describe the first case of de novo fibrillary GN in a renal transplant patient with HepC where the primary renal disease was biopsy proven type 1 MPGN. We discuss this relationship in detail.

Hepatitis C and renal transplantation

PURPOSE OF REVIEW

The purpose of this review is to describe the new insights of hepatitis C virus (HCV) infection and renal transplantation.

RECENT FINDINGS

HCV is its most frequent cause of liver disease after transplantation. In the long run, HCV infection can lead to cirrhosis, hepatocarcinoma and death in some patients. As interferon is generally contraindicated after transplantation, the best way to treat patients is before transplantation. Long-term patient and graft survival rates are lower in HCV-positive patients than in HCV-negative graft recipients. HCV infection is an independent risk factor for death and graft loss. Mortality is higher, mainly as a result of cardiovascular complications, liver disease and infections but is lower than in HCV-positive patients on the transplant waiting list. New-onset diabetes after transplantation (NODAT), and HCV-related glomerulonephritis, together with chronic rejection and notably transplant glomerulopathy can contribute to graft failure. Despite this factor, transplantation is the best option for the HCV-positive patient on dialysis. Renal transplantation with kidneys from donors with positive anti-HCV antibodies into HCV RNA-positive recipients seems to be safe in the long term.

SUMMARY

Renal transplantation is the therapy of choice for dialysis patients with HCV infection. To improve the results, a careful follow-up in the outpatient clinic for early detection of HCV-related complications is mandatory.

Advances in the understanding of transplant glomerulopathy

Transplant glomerulopathy is a sign of chronic kidney allograft damage. It has poor survival and no effective therapies. This entity develops as a maladaptive repair/remodeling response to sustained endothelial injury and is characterized by duplication/multilamination of capillary basement membranes. This review provides up-to-date information for transplant glomerulopathy, including new insights into underlying causes and mechanisms, and highlights unmet needs in diagnostics. Transplant glomerulopathy is widely accepted as the principal manifestation of chronic antibody-mediated rejection, mostly with HLA antigen class II antibodies. However, recent data suggest that at least in some patients, there also is an association with hepatitis C virus infection, autoimmunity, and late thrombotic microangiopathy. Furthermore, intragraft molecular studies reveal nonresolving inflammation after sustained endothelial injury as a key mechanism and therapeutic target. Unfortunately, current international criteria rely heavily on light microscopy and miss patients at early stages, when they likely are treatable. Therefore, better tools, such as electron microscopy or molecular probes, are needed to detect patients when kidney injury is in an early active phase. Better understanding of causes and effector mechanisms coupled with early diagnosis can lead to the development of new therapeutics for transplant glomerulopathy and improved kidney outcomes.

Recipient survival and graft survival are not diminished by simultaneous liver-kidney transplantation: an analysis of the united network for organ sharing database

Recipients of solitary liver and kidney transplants are living longer, and this increases their risk of long-term complications such as recurrent hepatitis C virus (HCV) and drug-induced nephrotoxicity. These complications may require retransplantation. Since the adoption of the Model for End-Stage Liver Disease, the number of simultaneous liver-kidney transplantation (SLK) procedures has increased. However, there are no standardized criteria for organ allocation to SLK candidates. The aims of this study were to retrospectively compare recipient and graft survival with liver transplantation alone (LTA), SLK, kidney after liver transplantation (KALT), and liver after kidney transplantation (LAKT) and to identify independent risk factors affecting recipient and graft survival. The United Network for Organ Sharing/Organ Procurement and Transplantation Network database (1988-2007) was queried for adult LTA (66,026), SLK (2327), KALT (1738), and LAKT procedures (242). After adjustments for potential confounding demographic and clinical variables, there was no difference in recipient mortality rates with LTA and SLK (P = 0.02). However, there was a 15% decreased risk of graft loss with SLK versus LTA (hazard ratio = 0.85, P < 0.001). The recipient and graft survival rates with SLK were higher than the rates with both KALT (P <0.001 and P <0.001) and LAKT (P = 0.003 and P < 0.001). The following were all identified as independent negative predictors of recipient mortality and graft loss: recipient age ≥ 65 years, male sex, black race, HCV/diabetes mellitus status, donor age ≥ 60 years, serum creatinine level ≥2.0 mg/dL, cold ischemia time > 12 hours, and warm ischemia time > 60 minutes. Although the recent increase in the number of SLK procedures performed each year has effectively decreased the number of potential donor kidneys available to patients with end-stage renal disease (ESRD) awaiting kidney transplantation, SLK in patients with end-stage liver disease and ESRD is justified because of the lower risk of graft loss with SLK versus LTA as well as the superior recipient and graft survival with SLK versus serial liver-kidney transplantation.

The impact of hepatitis C virus donor and recipient status on long-term kidney transplant outcomes: University of Wisconsin experience

The survival benefit of transplanting hepatitis C (HCV)-positive donor kidneys into HCV-positive recipients remains uncertain. The purpose of this study was to assess the effect of HCV-status of the donor (D) kidney on the long-term outcomes in kidney transplant recipients (R). We evaluated 2169 consecutive recipients of deceased-donor kidney transplants performed between 1991 and 2007. The following HCV cohorts were identified: D-/R- (n = 1897), D-/R+ (n = 59), D+/R- (n = 118), and D+/R+ (n = 95). Patients were followed for a mean of 6.02 (standard deviation = 4.26) yr. In a mulitvariable Cox-proportional hazards model, D+/R+ cohort had significantly lower patient survival (adjusted-hazard ratio [HR] 2.1, 95% CI [1.4-2.9]) with respect to the reference D-/R- group, whereas mortality was not increased in D-/R+ group. The rate of graft loss was increased in both D+/R+ and D-/R+ but was comparable with each other (adjusted-HR 1.8, 95% CI [1.4-2.5]) vs. adjusted-HR 2.0, 95% CI [1.4-2.8], respectively). D-/R+ cohort experienced significantly higher rate of rejection (adjusted-HR 1.7, 95% CI [1.2-2.5]) and chronic allograft nephropathy (adjusted-HR 2.1, 95% CI [1.2-3.7]). Neither donor nor recipient HCV-status impacted the risk of recurrent or de novo GN. Transplanting HCV-positive kidneys as opposed to HCV-negative kidneys into HCV-positive recipients provided similar graft survival but compromised patient survival in the long term.

Overlapping pathways to transplant glomerulopathy: chronic humoral rejection, hepatitis C infection, and thrombotic microangiopathy

Transplant glomerulopathy (TG) has received much attention in recent years as a symptom of chronic humoral rejection; however, many cases lack C4d deposition and/or circulating donor-specific antibodies (DSAs). To determine the contribution of other causes, we studied 209 consecutive renal allograft indication biopsies for chronic allograft dysfunction, of which 25 met the pathological criteria of TG. Three partially overlapping etiologies accounted for 21 (84%) cases: C4d-positive (48%), hepatitis C-positive (36%), and thrombotic microangiopathy (TMA)-positive (32%) TG. The majority of patients with confirmed TMA were also hepatitis C positive, and the majority of hepatitis C-positive patients had TMA. DSAs were significantly associated with C4d-positive but not with hepatitis C-positive TG. The prevalence of hepatitis C was significantly higher in the TG group than in 29 control patients. Within the TG cohort, those who were hepatitis C-positive developed allograft failure significantly earlier than hepatitis C-negative patients. Thus, TG is not a specific diagnosis but a pattern of pathological injury involving three major overlapping pathways. It is important to distinguish these mechanisms, as they may have different prognostic and therapeutic implications.

Dilemma of HCV infection in renal transplant recipients

Hepatitis C virus, which usually starts during dialysis therapy, is currently the main cause of chronic liver disease in such population. The majority of patients acquired the disease through intravenous drug use or blood transfusion, with some risk factors identified. In this review we are dealing with the effect of renal transplantation on HCV infection and HCV-related complications after renal transplantation. Moreover, we are discussing the therapeutic options of HCV infection before and after renal transplantation, the best immunosuppressive protocol and lastly graft and patient survival in patients who underwent pretransplant management vs. those who were transplanted without treatment.

Infection and chronic allograft dysfunction

With the advent of more potent immunosuppressive regimens, the incidence of acute rejection following renal transplantation has declined sharply in recent years. In spite of this, long-term graft outcomes remain suboptimal because of relentless attrition by cumulated insults to the allograft. As acute rejection rates have declined, other causes of graft injury and loss have recently emerged. Among these, infectious diseases remain a persistent threat and can be associated with allograft dysfunction. This group includes nephropathy due to polyoma (BK) virus infection, cytomegalovirus disease, and bacterial infection (the latter most commonly arising from the urinary tract). Rarer infectious causes of chronic allograft dysfunction include cryoglobulinemia associated with hepatitis C, Epstein-Barr virus-associated posttransplant lymphoproliferative disease, and direct cytotoxicity from adenoviral infection or parvovirus B19.

Impact of hepatitis B and C virus infections on kidney transplantation: a single center experience

OBJECTIVE

The impacts of hepatitis C virus (HCV) and hepatitis B virus (HBV) infections on patient and renal graft survivals are controversial. This study sought to evaluate the effects of pretransplantation HCV and HBV infections on renal transplant patients and their grafts at our center.

PATIENTS AND METHODS

We retrospectively examined 1224 renal transplantations performed between 1992 and 2006, including 28 HBsAg positive; 64, anti-HCV; 9, anti-HCV plus HBsAg positive; and 1123, negative for anti-HCV and HBsAg. The mean posttransplantation follow-up was 5.6 +/- 4.1 years.

RESULTS

The prevalences of HBV infection were 6.2% in 1994 and 2.3% in 2006 and those of HCV infection were 6.8% in 1998 and 5.2% in 2006. The rejection rate was higher among HBV+ (46.4%) and HCV+ (40.6%) groups than the negative groups (31.5%), but it was not significant. There were no significant differences in patient and graft survivals among the groups. The major cause of patient death was liver failure among patients with concomitant HBV+ and HCV+ infections and cardiovascular disease among HCV+ and negative patients.

CONCLUSIONS

There has been a decrease in the prevalence of recipients with hepatitis virus infections over the last 15 years. Patient and graft survivals were not affected by HCV or HBV infection.

Transplantation in the patient with hepatitis C

Hepatitis C virus (HCV) infection is the most frequent cause of liver disease after renal transplantation. Its clinical course is irrelevant in the short term, except for rare cases of fibrosing cholestatic hepatitis. However, in the long run, HCV infection can lead to major liver complications. Because interferon (IFN) is generally contraindicated in renal transplant patients, the best approach is to treat patients on dialysis. Until more information with pegylated-IFN is available, the use of alpha-IFN monotherapy is recommended. Most of the patients with sustained virological response remain HCV RNA negative after transplantation. HCV-positive renal transplant patients have a higher risk for proteinuria, chronic rejection, infections and post-transplant diabetes (PTDM). Long-term patient- and graft-survival rates are lower in HCV-positive patients. Mortality is higher, mainly as a result of liver disease and infections. HCV can contribute to the development of certain neoplasias such as post-transplant lymphoproliferative disease (PTLD). HCV infection is also an independent risk factor for graft loss. PTDM, transplant glomerulopathy and HCV-related glomerulonephritis can contribute to graft failure. Despite this, transplantation is the best option for end-stage renal disease in HCV-positive patients. Several measures to minimize the consequences of HCV infection have been recommended. Adjustment of immunosuppression and careful follow up in the outpatient clinic for early detection of HCV-related complications are mandatory.

Prevalence of hepatitis B and C markers in glomerular diseases

OBJECTIVE

To study the prevalence of hepatitis B and C viruses in patients with glomerulonephritis (Gn). Material and methods. This was a retrospective study of 89 patients (36 females, 53 males) diagnosed with Gn. Infection with hepatitis B and C was studied by means of serological methods; if patients presented hepatitis C antibodies, the presence of viral RNA in serum was detected by means of quantitative polymerase chain reaction. The control group comprised 59,546 first-time blood donors.

RESULTS

None of the patients were positive for hepatitis B surface antigen (HBsAg). In the control group there were 168 HBsAg positives. The prevalence of HBsAg in the control group (0.28%) was not significantly different (p = 0.614) from that in the patient group. Four patients with Gn were positive for hepatitis C virus (HCV) antibodies, and in three of these RNA HCV was also positive. The histological diagnoses in the four cases with HCV antibodies were: focal and segmental glomerulosclerosis; crescentic IgA nephropathy; diffuse proliferative Gn; and membranous Gn. The first three patients also presented other pathologies potentially linked to Gn, namely left renal agenesis, heavy alcohol intake/chronic liver disease and HIV seropositivity, respectively. Only the patient with membranous Gn, in whom other causes were disregarded, received antiviral treatment, although RNA HCV remained positive. In the control group, 141 cases were positive for HCV antibodies (prevalence 0.24%). The prevalence in the study group was significantly higher (p < 0.001).

CONCLUSION

HCV is more prevalent in patients with Gn than in those without, and this is the opposite of the situation with HBsAg.

Severity of primary MPGN, rather than MPGN type, determines renal survival and post-transplantation recurrence risk

Previous studies suggested that membranoproliferative glomerulonephritis (MPGN) type II has a worse renal survival and an unacceptable risk of recurrence post transplantation. We hypothesised that other factors may determine this risk. We analysed all cases (n=70) of MPGN diagnosed by renal biopsy in Ireland from 1972 to 1995. We used Cox regression analysis to determine factors that were independently predictive of renal failure. MPGN II had more crescent formation and mesangial proliferation (P<0.05). Mean follow-up duration was 13.8 years, during which time 41 (58.6%) developed end-stage renal failure (ESRF). The median time to ESRF was 8.3 years (95% confidence interval 5.7-10.9) and 5-, 10-, and 20-year probabilities of ESRF were 32, 54, and 70%, respectively. Multivariate analysis revealed that severity of interstitial fibrosis (P<0.05), crescent formation (P<0. 01) and mesangial proliferation (P<0.05) were independently associated with ESRF. Decade of diagnosis, age, MPGN type, and creatinine or complement level at baseline did not predict renal survival in this model. In 21 (49%) of the 43 renal transplants, MPGN recurred. Younger age at initial diagnosis (P<0.01) and the presence of crescents on the original biopsy (P<0.005) were independently associated with recurrence on multivariate analysis. MPGN type was not associated with recurrence in this model. Contrary to previous reports, after controlling for crescent formation, MPGN II was not associated with more ESRF or recurrence in the allograft. It is therefore the more aggressive glomerular changes associated with MPGN II, rather than the disease type per se, that determine outcome.

Effect of chronic viral hepatitis on graft survival in Saudi renal transplant patients

BACKGROUND

In Saudi Arabia the prevalence of hepatitis C among hemodialysis patients is very high ranging from 60 to 80%. A large number of these dialysis patients go for renal transplant, resulting into a higher prevalence of hepatitis C virus (HCV) infection in renal transplant patients. Yet no current systematic report is available on the influence of hepatitis C status on patient and graft survival. The present study was therefore undertaken to address this objective.

METHODS

Retrospective analysis of data of 448 renal transplantation subjects was undertaken. The mean follow-up period was 5.85 +/- 2.7 (median 5.3) years. The factors associated with renal graft survival were reviewed and these include: age, sex, and type of donor, immunosuppressive medication, episodes of infection, blood pressure, serum creatinine, and status of hepatitis. The primary end-points were renal graft function and patient survival. Logistic regression, COX regression analysis, and Kaplan-Meier survival estimates were used to evaluate the influence of hepatitis C on the above parameters.

RESULTS

Among 448 recipients of first kidney transplant patients, 286 (63.8%) were positive for HCV infection. In the HCV-positive group, 204 (71.32%) were males. Kaplan-Meier survival analysis showed a significantly better graft survival for HCV-negative patients than HCV-positive patients (p < 0.001; log-rank test). Logistic regression analysis and COX regression analysis have shown different grades of graft dysfunction were present in HCV-positive patients after adjustment for covariates: age, sex, blood pressure, type of donor, and immunosuppressive medication; the presence of HCV was a major predictor of bad outcome and significantly influenced graft survival (odds ratio = 4.37; 95% Cl = 1.81-4.77). Significant deterioration of liver function was noted in HCV-positive patients at the last follow-up, taking ALT as a marker (ALT level 80.6 +/- 5.8 U/l at the last follow-up versus 49.5 +/- 32 U/l at baseline p < or = 0.0001). Sixteen patients had a chronic active course and 1 patient developed biopsy-proven liver cirrhosis and portal hypertension. A serious and significantly greater incidence of fatal chest infections was seen in HCV-positive patients. Although mortality was greater in HCV-positive versus HCV-negative patients (20 vs. 7), the difference did not attain statistical significance (p = 0.23) and none of the patients died as a result of hepatic failure.

CONCLUSION

The presence of HCV infection greatly influenced graft survival in renal transplant patients and a higher proportion of infected patients had renal and hepatic dysfunction. A significant increase in fatal chest infections was noted in HCV-positive patients. Overall mortality was higher in HCV-positive patients, but it was not statistically significant. All measures should be taken to prevent HCV transmission in the dialysis population. Renal transplant recipients with HCV infection need close monitoring for both graft and liver function.

EAU guidelines on renal transplantation

OBJECTIVES

To produce a guidelines text, on behalf of the European Association of Urology, providing insights in the issues surrounding renal transplantation.

METHOD

A group of international experts in renal transplantation carried out a non-structured literature review on available medical databases and urological literature.

RESULT

A guideline text is presented providing an overview of key issues involved in the patients' management such as assessment of donors, pre-transplant evaluation, techniques, management, post-transplant care, etc.

CONCLUSION

The current text represents a consensus statement developed by a group of international experts in renal transplantation.

Interferon therapy in hemodialysis patients with chronic hepatitis C: study of tolerance, efficacy and post-transplantation course

BACKGROUND

The potential benefit of pre-transplant treatment of chronic hepatitis C on long-term evolution after renal transplantation is not clear.

METHODS

Fifty successive renal transplant candidates had their sera positive for HCV RNA and a biopsy-proven chronic hepatitis. Out of these, 18 patients received a standard course of interferon-alpha2b (IFN; 3 MU three times weekly after hemodialysis sessions for 6 months).

RESULTS

IFN was discontinued in 2 patients (11%) due to persistent leukopenia. HCV RNA turned negative in 10 patients of the treatment group and in none of the control group. Two patients of the IFN group had a virological relapse post-transplantation. Post-transplant follow-up periods were 41.5 +/- 15 and 50 +/- 16 months for the treated and control groups respectively. Transaminases remained normal in all patients of the IFN group after transplantation. In contrast, biochemical evidence of acute and chronic hepatitis was observed in 5 (p = 0.03) and 13 (p = 0.002) patients, respectively, of the control group. Logistic regression analysis identified non-receiving IFN before transplantation as a risk factor for post-transplant hepatic dysfunction (odds ratio = 11.7, p = 0.003) and for chronic allograft nephropathy (odds ratio = 11.6, p = 0.02).

CONCLUSIONS

IFN-treated patients had a significantly better post-transplant hepatic function and significantly lower rates of chronic allograft nephropathy.

Hepatitis C virus infection and renal disease after renal transplantation

Hepatitis C virus (HCV) infection is the main cause of chronic liver disease after renal transplantation (RT). It is considered in some series to be a risk factor for graft loss and patient death. Also, HCV has been implicated in the pathogenesis of glomerular diseases in native and transplanted kidneys. The presence of membranoproliferative (MP) or membranous (M) glomerulonephritis (GN) in HCV-positive patients has been well documented after RT, but there is no clear data concerning the real prevalence of HCV-induced glomerulonephritis. MPGN with or without cryoglobulinemia and MGN have been described in HCV RNA-positive patients in general without severe liver disease. Also, there is a possible association between HCV infection and acute/chronic transplant glomerulopathy. Renal thrombotic microangiopathy has been described in HCV-positive patients with positive anti-cardolipin antibodies. The pathogenesis of MPGN and MGN in HCV patients after RT seems to be similar to that which occurs in native kidneys: the deposition of immune complexes containing HCV proteins in the glomeruli. Renal biopsy, using light microscopy, immunofluorescence techniques, and electron microscopy, is useful to achieve a correct diagnosis. Unfortunately, interferon is not recommended due to the significant risk of rejection. The possibility of pegylated interferon needs to be tested. Ribavirin can improve proteinuria but HCV RNA remains positive. Finally, recent data suggest that the use of interferon in HCV patients on dialysis can negate HCV RNA and prevent associated glomerulonephritis after RT.

Impact of HCV infection on first cadaveric renal transplantation, a single center experience

BACKGROUND

Controversy still persists regarding the impact of HCV infection on renal transplant recipients. This study aimed to evaluate the effect of anti-HCV antibody status on patients and grafts of renal transplants at a single center.

METHODS

We examined 299 first cadaveric renal transplants performed between July 1981 and May 2000 at our hospital, including 129 patients with anti-HCV antibody positive (HCV+ group) and 170 patients with anti-HCV antibody negative (HCV- group). The HBsAg of the 299 patients were all negative throughout the follow-up period. Causes of graft failure and patient death were analyzed. Patient and graft cumulative survival were compared between HCV+ and HCV- groups. Multivariate analysis with Cox proportional hazard model were calculated for risk hazards of outcome.

RESULTS

Overall cumulative patient survival was 97.72, 85.63 and 71.31% at 1, 10, and 15 yr, respectively, in the HCV+ group, compared with 95.02, 67.85 and 59.83% at 1, 10 and 15 yr, respectively, in the HCV- group (p = 0.014). The major cause of patient death in both groups was infection with 26.67% in HCV+ group and 60.87% in HCV- group. Cumulative graft survival in the HCV+ group revealed 92.26, 55.97 and 26.16% at 1, 10 and 15 yr, respectively, compared with 88.07, 58.34 and 58.32% at 1, 10 and 15 yr, respectively, in the HCV- group (p = 0.700). The major cause of graft failure was chronic allograft dysfunction (56.82%) in HCV+ group, and patient death (32.43%) in the HCV- group. Multivariate analysis of patient survival revealed anti-HCV antibody+ had lesser risk hazard (aRR: 0.30, p = 0.002), chronic hepatitis had higher risk hazard (aRR: 1.90, p = 0.135), male recipient had higher risk hazard (aRR: 2.18, p = 0.051), and older recipients (age >55) also had higher risk hazard (aRR: 4.21, p = 0.063). Analysis of graft survival revealed only older donors (age >35) had higher risk hazard (aRR: 1.90, p = 0.081).

CONCLUSIONS

The study revealed that patients with anti-HCV antibody had higher incidence of chronic hepatitis, chronic allograft dysfunction and post-transplantation nephrotic syndrome. Graft survival tended lower in the very long time. However, patients with anti-HCV antibodies had better patient survival when compared with patients without HCV antibodies up to 15 yr follow up. Patients of hepatitis C group without clinical chronic hepatitis was associated with best patient survival.