Renal manifestations of hepatitis C virus infection

Hepatitis C and renal disease: an update

Hepatitis C is both a cause and a complication of chronic renal disease. Chronic infection with hepatitis C virus (HCV) can lead to the immune complex syndromes of cryoglobulinemia and membranoproliferative glomerulonephritis (MPGN). The pathogenetic mechanisms for these conditions have not been defined, although they are clearly caused by the chronic viral infection. Management of HCV-related cryoglobulinemia and MPGN is difficult; antiviral therapy is effective in clearing HCV infection in a proportion of patients, but these conditions can be severe and resistant to antiviral therapy. Hepatitis C also is a complicating factor among patients with end-stage renal disease and renal transplants. The source of HCV infection in these patients can be nosocomial. Screening and careful attention to infection control precautions are mandatory for dialysis units to prevent the spread of hepatitis C. Prevention of spread is particularly important in these patients because HCV infection is associated with significant worsening of survival on dialysis therapy, as well as after kidney transplantation. Furthermore, therapy for hepatitis C is problematic, only partially effective, and associated with significant side effects in this population. There are significant needs in both basic and clinical research in the pathogenesis, natural history, prevention, and therapy for hepatitis C in patients with renal disease.

Hypothesis: dysregulation of immunologic balance resulting from hygiene and socioeconomic factors may influence the epidemiology and cause of glomerulonephritis worldwide

Glomerular diseases show diverse epidemiological characteristics throughout the world, which has been suggested to be caused by differences in genetics of the underlying populations or environmental exposure to the putative antigens or agents that either trigger or induce the disease. Recently, an alteration in immune balance of the T helper 1 (T(H)1) and T helper 2 (T(H)2) subsets has been implicated as a mechanism to explain the relative increase in allergic diseases in industrialized nations. According to the Hygiene Hypothesis, overcrowding and poor hygiene early in life may protect from atopic diseases because exposure to microbes predisposes in favor of a T(H)1-dominant response. Conversely, dominance of the T(H)2 subset would be responsible for the increasing incidence of allergies. We present the hypothesis that this imbalance may help explain the predilection for membranoproliferative glomerulonephritis (GN) and mesangial proliferative GN to be associated with developing and/or poor nations, whereas immunoglobulin A nephropathy and minimal change disease are observed more commonly in industrialized nations. The implication of the Hygiene Hypothesis is that clinical expression of immune-mediated renal disease would depend on the prevailing T(H)1/T(H)2 balance, rather than the etiologic agent, and it may help explain the epidemiological pattern of glomerular diseases worldwide.

Hepatitis C virus-associated tubulointerstitial injury

BACKGROUND

Tubulointerstitial damage is recognized as a determinant of the prognosis of kidney disease. Various types of viral infection have been reported to induce tubulointerstitial lesions; however, that caused by hepatitis C virus (HCV) remains unclear, although glomerular lesions caused by this viral infection have been well documented.

METHODS

To identify any association, we retrospectively investigated 320 patients who underwent renal biopsy and did not have extrarenal diseases causing tubulointerstitial nephritis.

RESULTS

Of these patients, 13 patients had HCV infection and 307 patients did not. In a case-control study, HCV infection showed a significant association with the prevalence of tubulointerstitial injury. To offset the secondary tubulointerstitial change caused by advanced glomerulopathy, we performed a glomerular stage-matched comparison of patients with membranous nephropathy (MN). Nine patients with MN among the 13 HCV-infected patients and 18 HCV-negative patients with electron microscopic glomerular stage-matched MN were randomly selected from the overall pool of patients. Comparing areas of interstitial fibrosis and inflammatory cell infiltration, both were greater in HCV-infected than HCV-negative patients. In biopsy tissues from HCV-infected patients, positive signal for HCV was observed in the perinuclear area of tubular epithelial cells and infiltrating cells on immunohistochemistry and in situ hybridization. By a strand-specific reverse-transcription polymerase chain reaction for HCV, both genomic- and replicative-strand RNA were detected in renal tissues.

CONCLUSION

These results suggest that HCV infection is a potent pathogenic factor of tubulointerstitial injury.

Acute glomerulonephritis

Glomerulonephritis is an important cause of renal failure thought to be caused by autoimmune damage to the kidney. While each type of glomerulonephritis begins with a unique initiating stimulus, subsequent common inflammatory and fibrotic events lead to a final pathway of progressive renal damage. In this article the different forms of inflammatory glomerulonephritis and their diagnosis are discussed. In a review of therapy both immediate life saving treatment given when glomerulonephritis causes acute renal failure and more specific treatments designed to modify the underlying mechanisms of renal injury are considered.

Evolution of hepatitis C virus quasispecies in renal transplant patients with de novo glomerulonephritis

Long-term renal allograft survival in kidney transplant recipients infected by hepatitis C virus (HCV) may be influenced by the occurrence of de novo glomerulopathy associated with this virus. Therefore, we studied the evolution of HCV quasispecies in kidney transplant recipients infected by HCV with or without de novo glomerulopathy. The hypervariable region 1 (HVR-1) of the virus envelope was analyzed by cloning and sequencing 20 clones per sample to assess complexity and diversity from six kidney transplant patients who developed de novo glomerulopathy (group I) matched to six kidney transplant recipients without glomerular disease (group II), according to age, time since renal transplantation, and HCV genotype. Two sera were analyzed for each patient: one at the time of renal transplantation and the other at the time of appearance of de novo glomerulopathy, or after a similar duration since transplantation in group II. Overall, there was a significant increase of HCV viremia after the transplantation. This increase did not differ significantly between group I (+0.5 log copies/ml) and group II patients (+1 log copies/ml). The intersample diversity of HCV was similar in the two groups. Complexity and viral diversity were also similar at the time of transplantation. By contrast, complexity, diversity, and the proportion of nonsynonymous substitutions per nonsynonymous site were significantly higher after transplantation in group I patients. Our findings suggest a higher immune response and/or a particular cytokine production in patients developing de novo glomerulopathy rather than a direct effect of HCV on renal cells.

Renal manifestations of hepatitis C virus infection. Extrahepatic complications often are silent--and thus overlooked

Renal involvement often occurs in HCV infection. The most common renal manifestation is MPGN with or without cryoglobulinemia. Patients with glomerulonephritis may have no clinical evidence of systemic or liver involvement. Pathogenesis of HCV-associated MPGN is mediated by glomerular deposition of circulating immune complexes containing HCV and anti-HCV. The treatment of choice for MPGN is IFN-alpha. However, success is limited, and many patients fail to respond or experience relapse on discontinuation of therapy. Newer treatment modalities, such as high-dose IFN-alpha and recombinant IFN alpha-2b and ribavirin combination therapy, have led to improved suppression of HCV RNA levels.

Impact of hepatitis C virus status in pancreas transplantation: a case controlled study

Available data suggest that hepatitis C virus positive (HCV+) renal transplant patients may be at an increased risk of morbidity and mortality compared with HCV- patients. Limited data are available regarding the impact of HCV status in pancreas transplant patients. We compared the outcomes of 10 HCV+ patients undergoing pancreas transplantation (seven simultaneous kidney-pancreas, one pancreas after kidney, two pancreas alone) between 1/96 and 10/99 with 20 HCV- recipients that were matched for age, race, gender, timing of transplant, type of pancreas transplant, and surgical technique. Length of follow-up was not significantly different between the HCV+ group compared with the HCV- group (24 +/- 14 vs. 20 +/- 13 months; p=0.45). There was a trend toward a higher incidence of all cause mortality in HCV+ recipients compared with HCV- recipients, 30 vs. 10%, respectively (p=0.17). Additionally, the HCV+ recipients had a trend toward a higher incidence of sepsis-related mortality compared with HCV- recipients, 20 vs. 5%, respectively (p=0.19). Renal allograft survival was 50% in the HCV+ group compared with 94% in the HCV- group (p=0.02). Pancreas allograft survival was not significantly different between the groups, 60 vs. 80%, respectively (p=0.24). At 3, 6, 12 months, and end of follow-up, there were no differences in serum creatinine, amylase, C-peptide, or fasting glucose levels. However, there was a significantly higher incidence of proteinuria at last follow-up in the HCV+ recipients with a renal allograft when compared with HCV- recipients, 50 vs. 12.5%, respectively (p=0.05). In order to maintain comparable glycemic control between the groups, there was a significant increase in oral hypoglycemic requirement in HCV+ recipients compared with HCV- recipients, 33 vs. 0%, respectively (p=0.01). These data suggest that HCV+ pancreas transplant patients may be at an increased risk of graft dysfunction and morbidity. Further studies with more patients and longer follow-up are needed to fully define the impact of HCV status on pancreas graft survival and function.

Predictors of proteinuria and renal failure among women with HIV infection

BACKGROUND

Glomerular disease with proteinuria and renal failure are complications of human immunodeficiency virus (HIV) infection. While studies suggest risk factors for both include black race and lower CD4 lymphocyte count, they have not been established in population-based cohorts. This study examines the risk factors for proteinuria and renal failure in a large cohort of HIV-infected women not selected for the presence of renal disease.

METHODS

This prospective cohort includes 2059 women enrolled in the Women's Interagency HIV study (WIHS). WIHS is a longitudinal study of the clinical course of HIV infection in which subjects are followed biannually with a detailed exam including urine analysis, serum creatinine, CD4 lymphocyte count, and HIV RNA level. Proteinuria was defined as > or =+1 on urine dipstick exam on at least two consecutive urine analyses, and renal failure was defined as a doubling of serum creatinine. Multivariable logistic regression was used to estimate the associations between clinical variables and the presence of proteinuria on initial evaluation in a cross-sectional analysis. Cox proportional hazards regression was used to estimate the associations between clinical variables and time to renal failure among study participants with proteinuria in a prospective longitudinal analysis.

RESULTS

Of 2057 HIV-positive women, 32% (N=671) had proteinuria on initial evaluation. Predictors of proteinuria include increasing (log) HIV RNA level [odds ratio (OR)=1.05], black race (OR=2.0), absolute CD4 lymphocyte count < or =200 cells/mm3 (OR=1.41), and the presence of hepatitis C antibody (OR=1.27; all P < 0.0001). Absolute CD4 lymphocyte count < or =200 cells/mm3 [hazard ratio (HR)=3.57, P=0.001], detectable HIV RNA level (HR=2.33, P=0.02), increasing systolic blood pressure (HR=1.02, P=0.002), and decreasing albumin (HR=3.33, P=0.0001) and increasing creatinine (1.67, P=0.0001) were all associated with the development of renal failure.

CONCLUSIONS

This analysis establishes the associations between both increasing HIV RNA level and decreasing CD4 lymphocyte count with the presence of proteinuria and occurrence of renal failure. Additionally, it demonstrates an association between proteinuria and a positive hepatitis C antibody. To lessen the presence and progression of renal disease among HIV-infected patients, future research should focus on suppression of the HIV RNA level and improvement in CD4 lymphocyte count.

Cryoglobulinemic glomerulonephritis in thymic stromal lymphopoietin transgenic mice

Mixed cryoglobulins are complexes of immunoglobulins that reversibly precipitate in the cold and lead to a systemic disease in humans. Renal involvement usually manifests as a membranoproliferative glomerulonephritis with marked monocyte infiltration and, at times, intracapillary thrombi. Thymic stromal lymphopoietin (TSLP) is a recently cloned cytokine that supports differentiation and long-term growth of B cells. Here we report that TSLP overexpression in mice results in the development of mixed cryoglobulins, with renal involvement closely resembling cryoglobulinemic glomerulonephritis as it occurs in humans. One hundred twenty-three mice were sacrificed at monthly intervals, with at least five TSLP transgenic mice and five controls in each group. Blood, kidneys, spleen, liver, lung, and ear were collected and studied by routine microscopy, immunofluorescence, immunohistochemistry, and electron microscopy. TSLP transgenic animals developed polyclonal mixed cryoglobulinemia (type III) and a systemic inflammatory disease involving the kidney, spleen, liver, lung, and ears. Renal involvement was of a membranoproliferative type demonstrating thickened capillary walls with cellular interposition and double contours of the basement membrane, expansion of the mesangium because of increased matrix and accumulation of immune-deposits, subendothelial immune-deposits, focal occlusion of capillary loops, and monocyte/macrophage influx. In contrast to the severe glomerular lesions, the tubulointerstitium was not involved in the disease process. The renal lesions and the disease course were more severe in females when compared to males. We describe a mouse strain in which a B-cell-promoting cytokine leads to formation of large amounts of mixed cryoglobulins and a systemic inflammatory injury that resembles important aspects of human cryoglobulinemia. This is the first reproducible mouse model of renal involvement in mixed cryoglobulinemia, which enables detailed studies of a membranoproliferative pattern of glomerular injury.

Hepatitis C, cryoglobulinemia, and cutaneous vasculitis associated with unusual and serious manifestations

Hepatitis C viral infection is currently the leading cause of chronic hepatitis and cirrhosis. It also is a major predisposing factor for the development of hepatocellular carcinoma. It is estimated that approximately 1-2% of patients with hepatitis C infection have nonhepatic manifestations that are protean in nature. In this report, we describe six unusual cases of nonhepatic manifestations: abdominal vasculitis in two, peripheral neuropathy in two, and one patient each with central nervous system vasculitis and necrotizing cutaneous vasculitis. All patients had cutaneous vasculitis and cryoglobulinemia. None of our patients had cirrhosis, yet three of the six patients died. Because of the severe manifestations, aggressive therapy was instituted with interferon, immunosuppressive medications, i.v. immunoglobulin, and plasmapheresis. Our report underscores the importance of recognizing nonhepatic manifestations in patients with hepatitis C infection that may be associated with high morbidity and mortality.

In situ detection of hepatitis C virus RNA in salivary glands

Chronic hepatitis C virus (HCV) infection has been associated with several extrahepatic manifestations, among these, to diseases with oral manifestations such as Sjögren's syndrome or sialadenitis. HCV-RNA has been detected in saliva and in salivary glands from patients with sialadenitis by polymerase chain reaction. However, morphological evidence of HCV replication in salivary gland cells is needed to support a role for HCV in causing sialadenitis or Sjögren's syndrome. We have used in situ hybridization and immunohistochemistry to analyze the presence of HCV-RNA of sense and antisense polarity and HCV core antigen, respectively, in salivary gland biopsies from 19 patients with chronic sialadenitis or Sjögren's syndrome (eight anti-HCV-positive; 11 anti-HCV-negative). HCV-RNA of both positive and negative polarity as well as HCV core antigen were detected in the epithelial cells of the salivary gland biopsies from all of the anti-HCV-positive patients but in none of the anti-HCV-negative cases. The percentage of HCV-infected cells ranged from 25 to 48.8% in the patients studied. In conclusion, we have shown that HCV infects and replicates in the epithelial cells from salivary glands of patients with Sjögren's syndrome or chronic sialadenitis. However, its implication in the pathogenesis of these diseases deserves future research.

Recurrent type I membranoproliferative glomerulonephritis in a renal allograft: successful treatment with plasmapheresis

Recurrent disease is increasingly recognized as a cause of renal allograft dysfunction and failure. We describe a patient with type I membranoproliferative glomerulonephritis not associated with hepatitis C. The glomerular disease recurred in the renal allograft within 1 month of transplantation, leading to acute allograft dysfunction and nephrotic syndrome. Aggressive treatment with prednisone and plasmapheresis resulted in improvement in kidney function, improvement of the light microscopic picture, and removal of immune complexes from the glomerular subendothelial space.

Hepatitis C: an update on the silent epidemic

Hepatitis C virus (HCV) currently infects an estimated 2-3 million people in the United States and 175 million people globally. Over 80% of infected patients go on to develop chronic disease. Most patients remain asymptomatic despite silent, insidious progression of the disease. The sequelae of HCV-induced chronic liver disease accounts for 8,000-10,000 deaths annually in the United States and is currently the leading indication for liver transplantation. The cost of this epidemic to the United States was estimated in 1991 at $600 million in terms of medical expenses (excluding costs related to liver transplantation) and work lost. Over the last decade, since the viral genome of HCV was first sequenced in 1989, there has been a great increase in understanding of this infection. This review summarizes current knowledge about the hepatitis C epidemic with particular reference to epidemiology of infection, viral characteristics, risk factors for disease, diagnostic testing, clinical manifestations, and current, as well as potential, therapeutic options.

Prevalence of hepatitis C virus-associated mixed cryoglobulinemia after liver transplantation

Hepatitis C virus (HCV) infection is associated with mixed cryoglobulinemia and membranoproliferative glomerulonephritis. After orthotopic liver transplantation (OLT), isolated cases of HCV-associated mixed cryoglobulinemia have been reported. We determined the prevalence and clinical characteristics of mixed cryoglobulinemia in HCV-infected liver transplant recipients at our institution. Between January 1991 and February 1998, a total of 191 OLTs were performed in 178 patients. Among these transplant recipients, 53 patients (29.8%) had positive serological test results for HCV infection by second-generation enzyme-linked immunosorbent assay. We studied 31 HCV-positive (HCV+) and 21 HCV-negative (HCV-) transplant recipients (control group). Renal and liver function studies were performed, and cryoglobulin, rheumatoid factor, C3, C4, and serum HCV RNA levels and genotype were determined. Results were compared using unpaired Student's t-test for continuous variables and Fisher's exact test for categorical variables. Baseline characteristics were similar between the groups. Six patients in the HCV+ group (19%) had mixed cryoglobulins present at the time of evaluation compared with none in the HCV- group (P =. 036). The only parameter associated with cryoglobulins in the HCV+ group was rheumatoid factor (P <.01). In 3 HCV+ patients with cryoglobulins, extrarenal signs of cryoglobulinemia were present. Glomerulonephritis was found in 4 HCV+ patients. Two patients with purpura and cryoglobulinemia had reduced clinical manifestations after antiviral therapy. In conclusion, mixed cryoglobulinemia was found in approximately 20% of the HCV+ liver transplant recipients. The presence of purpura or glomerulonephritis suggests HCV-associated mixed cryoglobulinemia, a clinical syndrome that may respond favorably to antiviral therapy.

Hepatitis C virus RNA in kidney biopsies from infected patients with renal diseases

Hepatitis C virus (HCV) infection has been associated with several renal pathologies, including membranoproliferative and membranous glomerulonephritis. Although the presence of HCV proteins has been reported, there are no data concerning detection of the viral RNA in renal cells from HCV-infected patients with kidney disease. In this report we analysed, by in situ hybridization, the presence of HCV RNA in renal biopsies from 10 patients who were positive for antibodies to HCV (anti-HCV) and serum HCV RNA positive, and from four patients without HCV infection, with different renal disease. HCV RNA was detected in the renal biopsies from all of the 10 HCV-infected patients. Hybridization signals were detected in the tubular and capillary endothelial cells. No hybridization signals were found in the renal biopsies of the four anti-HCV-negative patients. In conclusion, our results demonstrate that HCV RNA is common in kidney cells of patients with renal diseases who are infected with HCV. The presence of HCV RNA is not necessarily associated with a pathogenetic consequence.

Outcome of hepatitis C virus-associated membranoproliferative glomerulonephritis after liver transplantation

BACKGROUND

Hepatitis C virus was the most frequent cause of liver failure requiring liver transplantation in our series. Hepatitis C virus infection has been associated with glomerulonephritis and, more frequently, type I membranoproliferative glomerulonephritis. Renal disease in patients with liver failure is often clinically silent and difficult to diagnose; thus, biopsy is required to establish the diagnosis. Our aim was to study the evolution of six patients diagnosed with membranoproliferative glomerulonephritis some months before liver transplantation.

METHODS

Liver transplantation alone was performed in four patients and combined liver-kidney transplantation in the remaining two, who were on hemodialysis for kidney failure. These patients were followed for a mean of 38.3+/-7.8 months. Evolution of proteinuria, renal function, hepatic function, and hepatitis C virus activity was studied.

RESULTS

In the four patients who underwent liver transplantation alone, proteinuria became negative initially and renal function remained stable. Proteinuria reappeared and renal function was altered in two of these patients at 17 and 36 months of follow-up, respectively, coinciding with a recurrence of active chronic hepatitis. In the two patients who received a combined liver-kidney transplant, proteinuria became negative, and their renal grafts currently maintain normal renal function.

CONCLUSIONS

Membranoproliferative glomerulonephritis does not constitute an absolute contraindication for liver transplantation alone; combined liver-kidney transplantations are reserved for patients with end-stage kidney failure. Proteinuria is reversed after liver transplantation, and recurrence seems to be associated with severe hepatitis C virus hepatic allograft disease relapse.

Management of membranoproliferative glomerulonephritis: evidence-based recommendations

Idiopathic membranoproliferative glomerulonephritis (MPGN) is one of the least common types of GN. This article critically evaluates the literature and generates evidence-based recommendations for the management of idiopathic MPGN. For all age groups, for idiopathic MPGN with normal renal function and asymptomatic nonnephrotic range proteinuria, no specific therapy is necessary (grades B and C). Close follow-up every three to four months, with specific attention to renal function, proteinuria, and blood pressure control, is recommended. In children with MPGN and nephrotic syndrome and/or impaired renal function, a trial of steroids is warranted (grade A). The best data suggest high-dose, alternate-day steroids for a period of 6 to 12 months (40 mg/m2 on alternate days). If no benefit is seen, discontinuation with close follow-up and attention to conservative treatment (that is, blood pressure control, use of agents to reduce proteinuria, and correction of metabolic abnormalities) is recommended. In adults with MPGN, impaired renal function, and/or nephrotic-range proteinuria, a trial of aspirin (325 mg daily), dipyridamole (75 to 100 mg tid), or a combination of the two for 12 months is reasonable (grade B). Again, if no benefits are seen, the treatment should be stopped. Attention to factors known to delay the progression of renal decline and close follow-up should be part of the treatment plan (grades B and C).

Glomerulonephritis

The differential diagnosis of glomerulonephritis without systemic disease includes poststreptococcal glomerulonephritis, IgA nephropathy, rapidly progressive glomerulonephritis (RPGN), and membranoproliferative glomerulonephritis (MPGN). Glomerular inflammation is probably induced directly by a nephritogenic streptococcal protein in poststreptococcal glomerulonephritis, and by mesangial deposition of abnormally glycosylated IgA1-containing immune aggregates in IgA nephropathy. In crescentic RPGN the role of cellular rather than humoral immune mechanisms is now becoming clear. Many patients with MPGN have chronic hepatitis C infection. There is no effective disease-specific therapy for poststreptococcal glomerulonephritis or IgA nephropathy. RPGN benefits from high-dose steroids and cytotoxic drug therapy with the addition of plasma exchange in disease induced by antibody to glomerular basement membrane. Antiviral therapies reduce the severity of MPGN due to hepatitis C virus. However, various new therapies directed at specific cytokines, growth factors, fibrin deposition, and other mediators of injury are being developed, as well as more specific and less toxic forms of immunotherapy.

Renal manifestations of hepatitis C infection

Hepatitis C is an important cause of renal disease, and renal complications may be the presenting manifestation of hepatitis C infection. About half of patients present with evidence of renal insufficiency, and up to one quarter present with nephrotic syndrome. Others present with proteinuria or evidence of diminished renal function. The pathogenesis of hepatitis C-associated renal disease remains incompletely defined, but most evidence suggests that glomerular injury results from deposition of circulating immune complexes in the subendothelium and mesangium. Membranoproliferative glomerulonephritis, with or without cryoglobulinemia, is the most common renal lesion. Interferon alpha-2b is currently the treatment of choice. However, success is limited, with many patients failing to respond or suffering relapse upon discontinuation of therapy. Studies of newer treatment modalities, such as longer courses of interferon or the use of ribavirin or immunosuppressive agents, are underway. Hepatitis C-associated renal disease may progress to end-stage renal failure requiring dialysis in about 10% of patients.

Renal thrombotic microangiopathy associated with anticardiolipin antibodies in hepatitis C-positive renal allograft recipients

Hepatitis C virus (HCV) infection has been associated with de novo or recurrent membranoproliferative glomerulonephritis and acute transplant glomerulopathy in transplanted kidneys. Recently, anticardiolipin antibodies (ACA) have been linked with chronic HCV infection. A few reports have suggested an association between ACA and renal allograft thrombosis. This study examines the clinical and pathologic features of HCV-positive renal allograft recipients at our institution. From 1990 to 1996, 379 kidney transplants were performed. We identified 18 recipients (4.8%) with HCV-positive serology pretransplant. Determination of IgG and IgM ACA was performed by enzyme-linked immunosorbent assay, using pretransplant sera. Among the 18 patients, five patients presented with biopsy-proven de novo renal thrombotic microangiopathy (RTMA), occurring 5 to 120 d (median, 14 d) after transplant. No differences in pretransplant characteristics were observed between patients with (n = 5) or without (n = 13) RTMA. All five patients had a positive ACA test (either IgG or IgM titer > 2 SD above normal), compared with only one of 13 patients without RTMA. The mean value for IgG ACA was significantly higher in the RTMA patients than in patients without RTMA (22.9 +/- 14.1 versus 6.9 +/- 4.9 IgG phospholipid units, P = 0.02); however, there were no significant differences in IgM ACA titers. Rheumatoid factor and complement C4 levels were normal in pretransplant sera of patients with RTMA. Patients with RTMA had their cyclosporine withdrawn (four of five) or the dose was decreased (one of five), and one of five underwent plasmapheresis. Four of five patients died within 5 yr after transplant, compared with no deaths in the other 13 patients. Finally, as a control group, seven HCV-negative renal allograft recipients who presented with RTMA/hemolytic uremic syndrome during the same time period were found to have normal ACA values (IgG or IgM). RTMA associated with ACA in HCV-positive renal allograft recipients may represent a new clinical entity. The occurrence of this syndrome may have deleterious consequences for patient and graft survival.

Hepatitis C-associated autoimmune disorders

Hepatitis C virus (HCV) infection has been associated with multiple autoimmune manifestations. The immune response to HCV infection encompasses the development of autoantibodies, immune complex formation and deposition, and cryoglobulinemia complicated by vasculitis, glomerulonephritis, or neuropathy. HCV infection has been associated with antiphospholipid antibody syndrome, RA, SLE, PM/DM, and thyroid disease. HCV-infected patients also have a high incidence of sicca symptoms with sialoadenitis, and reports of low-grade lymphoproliferative malignancies have emerged. Optimal treatment for HCV-related autoimmune disease remains to be determined, but patients seem to respond to immunosuppression with classic agents or interferon.

Pretransplant hepatitis C virus infection: a predictor of proteinuria after renal transplantation

BACKGROUND

Reports have suggested that hepatitis C virus (HCV)-infected kidney recipients may develop de novo glomerular lesions caused by the virus. We studied the relationships between pretransplantation anti-HCV antibodies and the occurrence of proteinuria and the link with short- and long-term patient and graft survival.

METHODS

A total of 322 consecutive renal recipients treated at a single center from 1989 to 1994 whose sera were routinely assayed for anti-HCV antibodies at the time of transplantation were analyzed. The risks of persistent proteinuria (>1 g/day), graft loss, or death were estimated by Kaplan-Meier analysis. The relationship between clinical variables and each outcome was examined by Cox multivariate regression analysis.

RESULTS

Before transplantation, 9.6% of the recipients were anti-HCV antibody positive. Persistent proteinuria developed in 13.6% recipients. The presence of anti-HCV antibodies was strongly associated with proteinuria (relative risk [RR]=5.36, 95% confidence interval [CI]=2.49-11.51). Proteinuria occurred more frequently in second grafts (RR=2.64, 95% CI=1.10-6.29). The number of HLA-A,B mismatches was an independent risk factor (RR=1.55, 95% CI=1.10-2.19). Recipient age (RR=0.80, 95% CI=0.63-1.02) and duration of dialysis (RR=0.86, 95% CI=0.77-0.96) were protective factors. Histology of biopsies from 26/44 recipients with proteinuria showed that de novo glomerular lesions were more frequent in HCV-positive patients, although the difference was not significant. One- and five-year graft survival rates were significantly worse in patients with proteinuria (90.7% and 41.1%) than in patients without it (95.6% and 91.8%) (P<0.00001). Despite the strong association between HCV infection and proteinuria, patient and graft survival rates in anti-HCV-positive and anti-HCV-negative recipients were similar.

CONCLUSIONS

The presence of anti-HCV antibodies before renal transplantation seems to be a major risk factor of proteinuria after transplantation. This may be due to glomerular lesions caused by HCV. However, anti-HCV has no impact on 5-year patient and graft survival.

Hepatitis C virus and renal transplantation

During the past 12 months additional evidence has emerged from several studies, indicating that hepatitis C virus infection is the most important liver disease after renal transplantation. A new, severe and rare entity called fibrosing cholestatic hepatitis can lead to early liver failure, although the most important complications appeared in the long-run. Encouraging results with ribavirin have been described. Although glomerular lesions and more severe infections can appear in hepatitis C virus patients, graft and patient survival rates in most series are similar to those in hepatitis-C-negative patients. Survival is also better among hepatitis-C-positive patients after renal transplantation than in hepatitis-C-positive patients on dialysis on the waiting list for transplantation. Finally, the use of kidneys from hepatitis-C-positive donors is suggested for transplant into hepatitis C RNA positive patients matching the hepatitis C genotype.

Nephrotic syndrome after liver transplantation in a patient with hepatitis C virus-associated glomerulonephritis

In recent years, hepatitis C virus infection has been reported to be typically associated with membranoproliferative glomerulonephritis and less frequently with membranous nephropathy. Treatment of hepatitis C with interferon-alpha can reduce viremia and improve renal disease. After liver transplantation for hepatitis C virus-associated liver failure, standard immunosuppressive protocols result in a significant increase in hepatitis C viremia. In this report we describe a patient with end-stage liver disease and biopsy-proven hepatitis C-associated glomerulonephritis who underwent liver transplantation. Within 1 month after transplantation, he developed a severe nephrotic syndrome that paralleled a marked increase in viremia. We discuss the possible pathogenic relationship between hepatitis C virus infection and the nephrotic syndrome that followed liver transplantation.

Response to high-dose interferon-alpha after failure of standard therapy in MPGN associated with hepatitis C virus infection

A 42-year-old man developed mixed cryoglobulinemia secondary to hepatitis C virus (HCV) infection with hypocomplementemia and nephrotic syndrome. His renal biopsy showed membranoproliferative glomerulonephritis type I (MPGN). Despite treatment with interferon-alpha, three million units three times a week for a total of 6 months, the patient continued to have hypocomplementemia, cryoglobulinemia, and nephrosis. After a course of high-dose interferon-alpha treatment consisting of ten million units daily for 2 weeks followed by 10 million units three times per week for an additional 6 weeks, HCV RNA and cryoglobulin testing became negative, complement levels increased to normal levels, and nephrotic syndrome remitted. This case confirms an association between HCV infection and MPGN and suggests a role for high-dose interferon-alpha treatment when conventional interferon therapy fails.

Membranous glomerulonephritis associated with hepatitis C virus infection in renal transplant patients

BACKGROUND

Hepatitis C virus (HCV) infection has been described in association with various types of glomerular diseases, usually type I membranoproliferative glomerulonephritis and rarely membranous glomerulonephritis (MGN). In this article, we describe the first series of MGN exhibited in renal transplant patients and associated with HCV infection.

METHODS

From January 1980 to December 1994, 2045 kidney transplantations were performed in our renal transplant units. A retrospective analysis demonstrated an overall 20% prevalence of HCV virus-positive patients; 409 transplanted patients were HCV positive (ELISA and RIBA).

RESULTS

Fifteen patients developed an allograft MGN (3.66%) 24 months after renal transplantation. MGN appeared in the form of significant proteinuria (>1.5 g/24 h) with stable renal function. In all cases, graft biopsy demonstrated a thickening of the capillary wall, subepithelial electron-dense deposits, and IgG and C3 diffuse granular deposits along the basal membrane. Ten cases were considered de novo, two cases were considered recurrent MGN, and three cases were considered undetermined because the primary renal disease was chronic glomerulonephritis. All patients showed negative antinuclear antibodies and cryoglobulins, normal complement, and negative rheumatoid factors. During follow-up (an average of 2 years), 12 patients developed a progressive worsening of renal function, with increased serum creatinine and persistent proteinuria; 8 of the 12 patients returned to dialysis. Of the remaining three cases, two patients showed partial remission of nephrotic syndrome after high doses of steroids, and one patient persisted with stable renal function and proteinuria (<2 g/24 h.).

CONCLUSIONS

In summary, HCV is preferentially associated with MGN in renal transplant patients, rather than with membranoproliferative glomerulonephritis as in the normal adult population. MGN associated with HCV infection has a similar clinical picture and outcome to posttransplant idiopathic de novo MGN, with persistent massive proteinuria and progressive deterioration of renal function.

Hepatitis C virus infection and autoimmunity

Hepatitis C virus (HCV) infection has been associated with a plethora of immune and autoimmune perturbations. We review serological and clinical autoimmune manifestations associated with HCV infection, discuss treatment regimens for HCV-related autoimmune diseases, and present a framework for understanding HCV-associated autoimmune disease by performing a computerized literature search from which representative articles were used and referenced. The immune response to HCV may include the development of cryoglobulins, rheumatoid factor, antinuclear antibodies (ANA), anticardiolipin, antithyroid, anti-liver/kidney/microsomal antibodies (anti-LKM), as well as HCV/anti-HCV immune complex formation and deposition. HCV infection is a significant cause of mixed essential cryoglobulinemia, which may then be complicated by cryoglobulinemic glomerulonephritis, vasculitis, or neuropathy. It has also been associated with membranous and membranoproliferative glomerulonephritis. Subsets of autoimmune hepatitis patients are infected with HCV and evidence suggests that HCV is a causative agent of antithyroid antibodies and autoimmune thyroid disease. Although cause-and-effect remain to be proved, there are reports of HCV infection preceding or coincident with polyarthritis, rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and polymyositis/dermatomyositis (PM/DM). HCV-infected patients also have a high incidence of sialoadenitis, and reports of low-grade lymphoproliferative malignancies have emerged. However, HCV is not a major causative factor for most autoimmune diseases. Optimal treatment for HCV-related autoimmune disease remains to be determined. Interferon alpha (IFN alpha) has successfully reduced viremia/transaminitis, cryoglobulins, proteinuria, and nephritis, but recurrent disease manifestations are frequent after discontinuation of therapy. Moreover, IFN alpha may precipitate or exacerbate autoimmune disease symptoms. HCV-related autoimmune disease also has been treated successfully with corticosteroids, azathioprine, and cyclophosphamide, although HCV viremia persists and may worsen.

Renal failure associated with hepatitis C virus infection. Improvement in renal function after treatment with interferon-alpha

Hepatitis C virus infection can result in mixed cryoglobulinemia and associated clinical syndromes including membranoproliferative glomerulonephritis. Reports regarding the efficacy of interferon-alpha (IFN-alpha) in the treatment of patients with membranoproliferative glomerulonephritis and chronic hepatitis C infection have been inconclusive regarding improvement of renal function. We describe two patients with chronic hepatitis secondary to hepatitis C virus complicated by mixed cryoglobulinemia and membranoproliferative glomerulonephritis who developed severe renal failure which resolved after treatment with standard doses of IFN-alpha 2b.

Focal segmental glomerulosclerosis with acute renal failure associated with alpha-interferon therapy

Both alpha- and beta- interferons (IFNs) have been increasingly used for the treatment of many types of malignancy, and recently the use of alpha-IFN in the management of hepatitis C virus (HCV) infection with or without renal involvement has been emphasized. We report a patient who developed nephrotic syndrome and acute renal failure while being treated with alpha-IFN for HCV infection. The renal biopsy showed focal segmental glomerulosclerosis and tubulointerstitial nephritis. Although several renal lesions have been described in association with either alpha-IFN treatment or HCV infection, focal segmental glomerulosclerosis has not been emphasized in either instance. This case also indicates that when renal abnormalities occur during treatment of HCV infection with alpha-IFN, kidney biopsy may define the responsible renal lesions, suggest possible association with other conditions, and serve as a guideline for proper management.

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

Previous studies suggest that there is an association between hepatitis C (HCV) infection and glomerular diseases in native and transplanted kidneys. However, the data are controversial. To reexamine this issue, we determined the prevalence of serum anti-HCV antibodies in patients with glomerulopathies of native kidneys (n = 105) and in patients with acute and chronic transplant glomerulopathy (TxGN) (n = 62). Compared with a control group of patients with diabetic nephropathy (n = 37, 0% HCV+), the prevalence of HCV antibodies was significantly higher in patients with focal glomerulosclerosis (FGS) (4 of 32, 13%, P = 0.04 by chi-square), but not in patients with membranous nephropathy (MGN) (1 of 19, 5%) or in patients with membranoproliferative glomerulonephritis (MPGN) (2 of 17, 12%). All of the patients with positive HCV serology had histories of intravenous (IV) drug use. Thus, HCV serology was negative in all of the patients with native glomerulopathies without histories of IV drug use. Compared with a group of 105 transplant patients without TxGN (1.8% HCV+), the prevalence of HCV antibodies was significantly higher in patients with acute (A)TxGN (12 or 41: 29%. P = 0.0004) and in patients with chronic (C)TxGN (9 of 27: 33%. P = 0.0004). Compared with controls, patients with ATxGN also had a significantly higher prevalence of serum immunoglobulin (Ig) M antibodies to cytomegalovirus (CMV) (3% and 26% of patients, respectively, P = 0.0004). However, there were no statistical associations between HCV and CMV serologies. These results do not support the postulate that HCV infection is associated with idiopathic native glomerulopathies; instead, the data suggest that the presence of HCV positivity in these patients can be explained by the inclusion of patients with a history of IV drug use. In contrast, these studies demonstrate for the first time an association between HCV infection and transplant glomerulopathies.

The high prevalence of severe early posttransplant renal allograft pathology in hepatitis C positive recipients

In the USA approximately 10% of candidates for renal transplantation have serum antibodies to hepatitis C (HCV). To assess the possible impact of HCV infection on early posttransplant events we assessed allograft complications during the first 6 months following renal transplantation in three groups of adult renal allograft recipients: (1) HCV antibody positive recipients (R-HCV) (n=32); (2) HCV negative recipients who received kidneys from HCV antibody positive donors (D-HCV) (n=48); and (3) HCV negative recipients of HCV negative allografts who were transplanted during the same time period as R-HCV (Ctrl) (n=204). Allograft biopsies were done for evaluation of allograft dysfunction during the first 6 months posttransplant in 58% of Ctrl, 42% of D-HCV, and 63% of R-HCV (not significantly different). The prevalence of acute tubulointerstitial rejection was similar among the 3 groups of patients. In contrast, compared with Ctrl, both R-HCV and D-HCV had a significantly higher prevalence of acute transplant glomerulopathy (Ctrl, 6%; R-HCV, 55%, P<.0001; D-HCV 40%, P=.0004). Acute vascular rejection was more common in R-HCV (60%) than in Ctrl (28%) (P=.009) and the prevalence of chronic vascular rejection was also higher in R-HCV (60%) than in Ctrl (31%) (P=.01). Furthermore, chronic vascular rejection was diagnosed earlier in R-HCV (64% of cases within one month posttransplantation) than in Ctrl (19% within one month) (P=.01). Death censored renal allograft losses occurred in 14% of Ctrl, 17% of D-HCV, and 26% of R-HCV (not significant). In conclusion, R-HCV patients have a high prevalence of severe acute pathologic findings in renal allograft biopsies obtained early after transplantation and develop chronic vascular rejection more often and earlier than HCV negative recipients. These studies also confirm the previously reported association of HCV with acute transplant glomerulopathy.

High incidence of hepatitis C virus infection in hemodialysis patients in units with high prevalence

The prevalence of hepatitis C virus (HCV) infection was evaluated in 227 hemodialysis patients from four units in Caracas, Venezuela, by using different second- and third-generation enzyme immunoassays (EIAs) and immunoblot assays. HCV antibodies were detected in 162 patients (71%) by the recombinant-based second-generation assays (Abbott and Ortho) and in 161 patients by the synthetic peptide-based EIA (UBI). Of the 162 HCV antibody-positive serum samples, 161 were confirmed to be positive by RIBA 3. HCV RNA was detected in 49 of 68 (72%) of the seropositive patients and in 5 of 21 (24%) of the seronegative ones. HCV RNA was not always correlated with an increase in alanine aminotransferase (ALT) levels. Among 20 patients positive for HCV RNA and for HCV antibodies (without any hepatitis B virus [HBV] marker), only 10 had elevated ALT levels. The possible interference of HBV for HCV replication was evaluated. No significant difference was found between the presence of HCV RNA and the presence of any HBV serological markers. The possible routes of transmission of HCV in hemodialysis patients are multiple, and some of them are still controversial. Of the HCV-positive patients, 30% received a blood transfusion, significantly more than the 15% found for the HCV-negative group. However, blood transfusions alone could not account for the high incidence observed in this group of patients (38% from 1994 to 1995). In conclusion, about one-quarter of the apparently non-HCV-infected patients were probably seroconverting, ALT may not be a useful indicator of HCV infection in hemodialysis patients, and nosocomial transmission of HCV may play a role in the spread of HCV in this group.

Lack of detection of negative-strand hepatitis C virus RNA in peripheral blood mononuclear cells and other extrahepatic tissues by the highly strand-specific rTth reverse transcriptase PCR

To further explore the controversial potential for extrahepatic replication of hepatitis C virus (HCV), the highly strand-specific rTth method of reverse transcriptase PCR was used to examine sera, liver, peripheral blood mononuclear cells, and other extrahepatic tissues from HCV-infected chimpanzees and humans. Positive-strand HCV RNA was present in the liver at approximately 10-fold-higher levels than negative-strand HCV RNA. No negative-strand RNA was detected in peripheral blood mononuclear cells or other extrahepatic tissues despite the presence of abundant positive-strand RNA. These data demonstrate that within the limits of sensitivity of this highly strand-specific reverse transcriptase PCR method, no extrahepatic replication of HCV was detected.

Hepatitis C--associated glomerular disease in liver transplant recipients

Hepatitis C virus (HCV) infection may be associated with extrahepatic illness including renal disease. We investigated the clinical and virological characteristics of three patients who developed a mesangial proliferative and sclerosing glomerulopathy alone or in association with membranoproliferative glomerulonephritis after liver transplantation for end-stage liver disease secondary to HCV infection. Using polymerase chain reaction technology and the IgM RIBA assay, viral load, genotype and IgM antibody response to HCV in the setting of glomerulonephritis was evaluated. Within 1 year of transplantation, the patients showed decreased renal function, proteinuria and recurrent hepatitis C liver disease. Likewise, HCV viral load increased following transplantation, whereas the viral genotypes remained unchanged. Although the first patient presented with classic type II cryoglobulinemia in association with glomerulonephritis, the second patient developed an IgM directed specifically against the hepatitis C core antigen. The third patient developed a low-titered IgM directed against the hepatitis C core antigen with rheumatoid factor activity but without cryoglobulinemia. All of the patients show IgM in glomerular capillary walls by biopsy. One patient has shown a clinical response to interferon (IFN) alfa-2b therapy without evidence of hepatic allograft rejection. The second and third patients have not responded to IFN or developed hepatic rejection. This study suggests that HCV-associated glomerulonephritis may complicate liver transplantation in conjunction with the production of increased amounts of IgM of variable specificity. The posttransplant setting may provide a unique situation in which to investigate the specific requirements for the onset of renal disease.