Acute renal allograft rejection following pegylated IFN-alpha treatment for chronic HCV in a repeat allograft recipient on hemodialysis: a case report

Use of Hepatitis C Virus Antibody-Positive Donors in Kidney Transplantation

Background The use of kidney donors with hepatitis C virus (HCV) has been arising as a possibility to increase the donor pool. It encompasses both the use of donors with positive and negative viremia, particularly since the advent of direct antiviral agents that produce sustained virologic response. Methodology We conducted a retrospective observational study to describe the experience of our transplantation center in the use of HCV antibody-positive (HCV-Ab+) kidneys. Results We performed five transplants with HCV-Ab+ donors. The median age of kidney recipients was 63 (interquartile range (IQR) = 54-71) years, and 60% (n = 3) were males. Two recipients received a second transplant. The median dialysis vintage was 1,414 (IQR = 1,103-2,806) days. The induction immunosuppression protocol was basiliximab in most patients (60%, n = 3), and all received maintenance immunosuppression with tacrolimus, mycophenolate mofetil, and prednisolone. One of the recipients had a personal history of cured HCV infection. Seroconversion occurred in half of the remaining patients, which was sustained during the follow-up. None of the patients developed HCV viremia. At the end of follow-up, mean creatinine and proteinuria were 1.45 ± 1.12 mg/dL and 0.099 ± 0.045 g/g, respectively. We did not observe any rejection episodes, need for dialysis, or recipient's death. Conclusions Our work aligns with the current literature that advocates that the use of these donors is safe and cost-effective and can be an effective strategy for expanding the donor pool and augmenting the transplantation volume. Seroconversion is a known risk whose mechanisms are not entirely understood, although it does not appear to be related to a higher transmission risk.

Efficacy and Safety of Direct-Acting Antivirals in Kidney Transplantation From HCV-Viremic Donors to Negative Recipients: A Meta-Analysis

Background:

With the development of direct-acting antiviral agents (DAAs), the research on kidney transplantation from Hepatitis C virus (HCV)-viremic donors to HCV-negative recipients has grown. The objective of this comprehensive analysis was to evaluate the efficacy and safety of DAAs in kidney transplantation from HCV-viremic donors to negative recipients.

Methods

Multiple databases were searched for a systematic and comprehensive up to March 2022. The primary outcomes included the percentage of sustained virological response at week 12 after the end of treatment (SVR12), adverse events (AEs; any grade), and severe adverse events (SAEs) as the endpoints. Publication bias was examined by using the funnel plots and Egger's test.

Results

In total, 16 studies with 454 subjects were included in the study and the pooled estimate of SVR12, AEs, and SAEs rates were 100.0% (95% CI: 99.2-100.0), 1.9%(95%CI: 0.0-4.9), and 0.0% (95%CI: 0.0-1.5). Subgroup analysis showed that pooled SVR12 rates were 100.0% (95%CI: 99.6-100.0) for genotype (GT)1a and 96.3% (95%CI: 83.3-100.0) for GT2; 100.0% (95%CI: 98.9-100.0) for DAAs treatments; and 100.0% (95%CI: 98.2-100.0) for prophylaxis subgroup. Egger's tests showed that no publication bias was found in this study.

Conclusion

This comprehensive analysis showed the high efficacy and safety of DAAs in kidney transplantation from HCV-viremic donors to HCV-negative recipients.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=246541.

Transplanting Organs from Donors with HIV or Hepatitis C: The Viral Frontier

A wide gap between the increasing demand for organs and the limited supply leads to immeasurable loss of life each year. The organ shortage could be attenuated by donors with human immunodeficiency virus (HIV) or hepatitis C virus (HCV). The transplantation of organs from HIV+ deceased donors into HIV+ individuals (HIV D+ /R+) was initiated in South Africa in 2010; however, this practice was forbidden in the USA until the HIV Organ Policy Equity (HOPE) Act in 2013. HIV D+/R+ transplantation is now practiced in the USA as part of ongoing research studies, helping to reduce waiting times for all patients on the waitlist. The introduction of direct acting antivirals for HCV has revolutionized the utilization of donors with HCV for HCV-uninfected (HCV-) recipients. This is particularly relevant as the HCV donor pool has increased substantially in the context of the rise in deaths related to drug overdose from injection drug use. This article serves to review the current literature on using organs from donors with HIV or HCV.

Hepatitis C-positive donor to negative recipient kidney transplantation: A real-world experience

BACKGROUND

Several studies have shown that transplanting a hepatitis C virus (HCV)-negative recipients with a HCV-positive donor is feasible in a research setting. In February 2018, we began transplanting HCV-negative recipients with HCV-positive donors as standard of care.

METHODS

All patients, except those with previously cured HCV and those with cirrhosis, were consented for HCV NAT-positive donor kidneys. After transplantation, patients were tested for HCV RNA until viremic. A direct-acting antiviral (DAA) agent was prescribed based on genotype and insurance approval. Sustained virologic response (SVR) at weeks 4 and 12 was recorded. Renal function and death censored graft survival at 1 year were evaluated and compared to recipients of HCV NAT-negative kidneys.

RESULTS

A total of 25 HCV NAT-positive donor kidney transplants from February to October 2018 were performed. All patients received basiliximab and maintained with tacrolimus, mycophenolate mofetil, and prednisone. Median time from viremia to start of DAA was 13 (8-22) days. The most common genotype was 1a (60%), followed by 3a (28%). The most commonly prescribed DAA was ledipasvir/sofosbuvir (56%), followed by velpatasvir/sofosbuvir (32%), and then glecaprevir/pibrentasvir (12%). All patients achieved initial SVR12, except one. One patient had a mixed-genotype infection requiring retreatment to achieve SVR12. Death censored graft survival was 96%. Recipients of HCV NAT-positive organs compared to HCV NAT-negative organs received younger donors (mean 35 ± 8.9 vs 45.1 ± 15.7 years; P < .01) and spent less time on the waitlist (median 479 (93-582) vs 1808 (567-2263) days; P = .02).

CONCLUSION

HCV NAT-negative recipients can be safely and successfully transplanted with HCV NAT-positive donor kidneys outside of a research protocol. Access to DAA and timely administration of therapy is important and an insurance approval process within the transplant center can be beneficial to patients. A case of mixed-genotype infection was presented, and although not as common, can be successfully treated. HCV organs can expand the organ pool and should no longer be considered experimental. The use of these organs in HCV-negative recipient's decreases waiting time, have excellent outcomes, and should be considered standard of care.

Hepatitis C Virus NAT-Positive Solid Organ Allografts Transplanted Into Hepatitis C Virus-Negative Recipients: A Real-World Experience

BACKGROUND AND AIMS

Hepatitis C virus (HCV)-viremic organs are underutilized, and there is limited real-world experience on the transplantation of HCV-viremic solid organs into recipients who are HCV negative.

APPROACH AND RESULTS

Patients listed or being evaluated for solid organ transplant after January 26, 2018, were educated and consented by protocol on the transplantation of HCV-viremic organs. All recipients were HCV nucleic acid test and anti-HCV antibody negative at the time of transplant and received an HCV-viremic organ. The primary outcome was sustained virological response (SVR) at 12 weeks after completion of direct-acting antiviral (DAA) therapy (SVR₁₂ ). Seventy-seven patients who were HCV negative underwent solid organ transplantation from a donor who was HCV viremic. No patients had evidence of advanced hepatic fibrosis. Treatment regimen and duration were at the discretion of the hepatologist. Sixty-four patients underwent kidney transplant (KT), and 58 KT recipients had either started or completed DAA therapy. Forty-one achieved SVR₁₂ , 10 had undetectable viral loads but are not eligible for SVR₁₂ , and 7 remain on treatment. One KT recipient was a nonresponder because of nonstructural protein 5A resistance. Four patients underwent liver transplant and 2 underwent liver-kidney transplant. Three patients achieved SVR₁₂ , 1 has completed DAA therapy, and 2 remain on treatment. Six patients underwent heart transplant and 1 underwent heart-kidney transplant. Six patients achieved SVR₁₂ and 1 patient remains on treatment.

CONCLUSIONS

Limited data exist on the transplantation of HCV-viremic organs into recipients who are HCV negative. Our study is the largest to describe a real-world experience of the transplantation of HCV-viremic organs into recipients who are aviremic. In carefully selected patients, the use of HCV-viremic grafts in the DAA era appears to be efficacious and well tolerated.

Infectious Complications Following Kidney Transplantation-A Focus on Hepatitis C Infection, Cytomegalovirus Infection and Novel Developments in the Gut Microbiota

The incidence of infectious complications, compared with the general population and the pre-transplant status of the recipient, increases substantially following kidney transplantation, causing significant morbidity and mortality. The potent immunosuppressive therapy given to prevent graft rejection in kidney transplant recipients results in an increased susceptibility to a wide range of opportunistic infections including bacterial, viral and fungal infections. Over the last five years, several advances have occurred that may have changed the burden of infectious complications in kidney transplant recipients. Due to the availability of direct-acting antivirals to manage donor-derived hepatitis C infection, this has opened the way for donors with hepatitis C infection to be considered in the donation process. In addition, there have been the development of medications targeting the growing burden of resistant cytomegalovirus, as well as the discovery of the potentially important role of the gastrointestinal microbiota in the pathogenesis of post-transplant infection. In this narrative review, we will discuss these three advances and their potential implications for clinical practice.

Changes in Utilization and Discard of HCV Antibody-Positive Deceased Donor Kidneys in the Era of Direct-Acting Antiviral Therapy

BACKGROUND

The availability of direct-acting antiviral (DAA) therapy might have impacted use of hepatitis C virus (HCV)-infected (HCV+) deceased donor kidneys for transplantation.

METHODS

We used 2005 to 2018 Scientific Registry of Transplant Recipients data to identify 18 936 candidates willing to accept HCV+ kidneys and 3348 HCV+ recipients of HCV+ kidneys. We compared willingness to accept, utilization, discard, and posttransplant outcomes associated with HCV+ kidneys between 2 treatment eras (interferon [IFN] era, January 1, 2005 to December 5, 2013 vs DAA era, December 6, 2013 to August 2, 2018). Models were adjusted for candidate, recipient, and donor factors where appropriate.

RESULTS

In the DAA era, candidates were 2.2 times more likely to list as willing to accept HCV+ kidneys (adjusted odds ratio, 2.072.232.41; P < 0.001), and HCV+ recipients were 1.95 times more likely to have received an HCV+ kidney (adjusted odds ratio, 1.761.952.16; P < 0.001). Median Kidney Donor Profile Index of HCV+ kidneys decreased from 77 (interquartile range [IQR], 59-90) in 2005 to 53 (IQR, 40-67) in 2017. Kidney Donor Profile Index of HCV- kidneys remained unchanged from 45 (IQR, 21-74) to 47 (IQR, 24-73). After adjustment, HCV+ kidneys were 3.7 times more likely to be discarded than HCV- kidneys in the DAA era (adjusted relative rate, 3.363.674.02; P < 0.001); an increase from the IFN era (adjusted relative rate, 2.783.023.27; P < 0.001). HCV+ kidney use was concentrated within a subset of centers; 22.5% of centers performed 75% of all HCV+ kidney transplants in the DAA era. Mortality risk associated with HCV+ kidneys remained unchanged (aHR, 1.071.191.32 in both eras).

CONCLUSIONS

Given the elevated risk of death on dialysis facing HCV+ candidates, improving quality of HCV+ kidneys, and DAA availability, broader utilization of HCV+ kidneys is warranted to improve access in this era of organ shortage.

Acute allograft rejection following interferon therapy for hepatitis C in recipients who have returned to dialysis after kidney transplant failure: case study

Interferon-based therapy remains the gold standard for hepatitis C in patients with chronic kidney disease; however, due to the high rate of IFN-induced rejection after transplant, treatment of HCV-infected kidney transplant recipients is recommended only in particular circumstances. We report the case of a 45-year-old Caucasian female with chronic hepatitis C (genotype 1b) who returned to hemodialysis following the complete functional loss of her kidney transplant. She started combination antiviral therapy with peg-IFN-α2a (135 mcg sc weekly) plus ribavirin (200 mg daily) nine months after the re-initiation of hemodialysis. Antiviral therapy was neither effective nor safe; ribavirin was stopped at week 38 due to hemolytic anemia; on-treatment HCV breakthrough was observed at week 48; and acute rejection occurred after four months of IFN-based therapy. Diagnosis of acute allograft rejection was suspected on the grounds of clinical, radiographic, and laboratory data. Allograft nephrectomy was then performed and histology showed acute-on-chronic rejection. This is an uncommon case of IFN-associated kidney rejection in an allograft recipient who had functional loss of her graft and had returned to hemodialysis. In view of the risk of rejection of renal allograft, and the limited efficacy of IFN-based treatment of hepatitis C, physicians should be aware of effective treatment with oral anti-viral agents and avoid the use of IFN in patients on maintenance dialysis with failed renal allograft.

Interferon-based anti-viral therapy for hepatitis C virus infection after renal transplantation: an updated meta-analysis

BACKGROUND

Hepatitis C virus (HCV) infection is highly prevalent in renal transplant (RT) recipients. Currently, interferon-based (IFN-based) antiviral therapies are the standard approach to control HCV infection. In a post-transplantation setting, however, IFN-based therapies appear to have limited efficacy and their use remains controversial. The present study aimed to evaluate the efficacy and safety of IFN-based therapies for HCV infection post RT.

METHODS

We searched Pubmed, Embase, Web of Knowledge, and The Cochrane Library (1997-2013) for clinical trials in which transplant patients were given Interferon (IFN), pegylated interferon (PEG), interferon plus ribavirin (IFN-RIB), or pegylated interferon plus ribavirin (PEG-RIB). The Sustained Virological Response (SVR) and/or drop-out rates were the primary outcomes. Summary estimates were calculated using the random-effects model of DerSimonian and Laird, with heterogeneity and sensitivity analysis.

RESULTS

We identified 12 clinical trials (140 patients in total). The summary estimate for SVR rate, drop-out rate and graft rejection rate was 26.6% (95%CI, 15.0-38.1%), 21.1% (95% CI, 10.9-31.2%) and 4% (95%CI: 0.8%-7.1%), respectively. The overall SVR rate in PEG-based and standard IFN-based therapy was 40.6% (24/59) and 20.9% (17/81), respectively. The most frequent side-effect requiring discontinuation of treatment was graft dysfunction (14 cases, 45.1%). Meta-regression analysis showed the covariates included contribute to the heterogeneity in the SVR logit rate, but not in the drop-out logit rate. The sensitivity analyses by the random model yielded very similar results to the fixed-effects model.

CONCLUSIONS

IFN-based therapy for HCV infection post RT has poor efficacy and limited safety. PEG-based therapy is a more effective approach for treating HCV infection post-RT than standard IFN-based therapy. Future research is required to develop novel strategies to improve therapeutic efficacy and tolerability, and reduce the liver-related morbidity and mortality in this important patient population.

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.

Cyclosporin A inhibits hepatitis C virus replication and restores interferon-alpha expression in hepatocytes

Hepatitis C virus (HCV) infection is the leading indication for liver transplantation and a major cause of graft failure. This study investigated whether cyclosporin A (CsA), a widely used immunosuppressant for organ transplantation, inhibits full cycle HCV replication and restores type I interferon (IFN) signaling pathway in human hepatocytes. CsA treatment of hepatocytes before, during, and after HCV infection significantly inhibited full cycle viral replication, which is evidenced by decreased expression of HCV RNA, protein, and infectious viruses in human hepatocytes. The suppression of HCV replication by CsA was associated with elevated levels of endogenous IFN-α in infected hepatocytes. Although CsA had little effect on IFN-α signaling pathway in uninfected hepatocytes, CsA treatment of HCV-infected hepatocytes specifically upregulated the expression of IFN regulatory factor-1 and inhibited the expression of suppressor of cytokine signaling-1 and protein inhibitor of activated signal transducers and activators of transcription-x, the primary negative regulators of IFN signaling pathway. These findings provide additional evidence to support the development of CsA-based prevention/treatment of HCV infection for transplant recipients.

Pegylated interferon monotherapy of chronic hepatitis C in dialysis patients: Meta-analysis of clinical trials

The efficacy and safety of pegylated interferon monotherapy in patients with chronic renal failure and chronic hepatitis C remains unclear, although a number of small clinical trials have been published addressing this issue. A systematic review of the literature with a meta-analysis of clinical trials was performed in order to assess efficacy and safety of initial pegylated interferon monotherapy in chronic renal failure patients with chronic hepatitis C. The primary outcome was sustained virological response (as a measure of efficacy); the secondary outcome was drop-out rate (as a measure of tolerability). The random effects model of Der Simonian and Laird was used, with heterogeneity and sensitivity analyses. Sixteen clinical trials (254 unique patients) were identified, five (31%) being controlled studies; the majority (15/16 = 94%) regarded patients on long-term dialysis. The summary estimate for sustained virological response and drop-out rate was 33% [95% Confidence Intervals (95%CI) 24-43] and 23% (95%CI, 14-33), respectively. The most frequent side-effects requiring interruption of treatment were haematological (18%) and gastrointestinal (14%). In the group of controlled clinical trials, the summary estimate for sustained viral response and drop-out rate was 38% (95% CI, 18-59), and 15% (95% CI, 3-26), respectively. The studies were heterogeneous with regard to sustained virological response and drop-out rate. Pegylated IFN does not provide an added benefit in terms of virological response in comparison with standard IFN monotherapy. Tolerance to pegylated-IFN monotherapy was unsatisfactory. Prospective trials are in progress to assess the optimal antiviral therapy for chronic hepatitis C in dialysis patients.

Hepatic disorders in chronic kidney disease

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infection are the most common and serious causes of liver damage in patients with chronic kidney disease (CKD). The natural histories of HBV and HCV infections in patients with CKD are not fully understood; however, recent evidence has emphasized the adverse effect of HBV and/or HCV infection on survival in this population. Chronic liver disease is the fourth most important cause of death after renal transplantation. The negative effect of HCV infection on survival among renal transplant recipients has been linked to liver dysfunction and extrahepatic complications, such as chronic glomerulonephritis, post-transplantation diabetes mellitus, chronic allograft nephropathy, and sepsis. The transmission of HCV by solid organ transplantation has been unequivocally demonstrated. Renal transplant recipients who receive kidneys from HCV-positive donors are at increased risk of death. Although several studies have shown that in patients with HCV infection and chronic renal failure renal transplantation is associated with better survival than is dialysis, recent clinical guidelines recommend that kidneys from HCV-infected donors should not be used in HCV-seropositive recipients without detectable HCV viremia. Monotherapy with conventional interferon has been suggested to be a useful treatment for hepatitis C infection in patients on dialysis. Although no evidence suggests that patients with CKD are more prone to suffer from hepatic toxic effects than individuals with normal kidney function, patients with CKD usually receive multiple medications; and drug interactions may, therefore, have a role in the pathogenesis of drug-induced liver disease in this population.

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.

The multiple facets of toll-like receptors in transplantation biology

Toll-like receptors (TLRs) belong to a family of pattern-recognition receptors for microbial products and endogenous molecules released by stressed cells. Experimental studies show that TLRs are involved in the process of acute allograft rejection and that their activation can prevent transplantation tolerance. Herein, we review the expression of TLRs and the impact of TLR signaling in different cell types in grafted organs including antigen-presenting cells, T and B lymphocytes, epithelial and endothelial cells. We then discuss the involvement of TLRs in the different phases of the rejection phenomenon and the impact of TLR-mediated events on regulatory circuits which dampen alloimmune responses.

HCV in patients with end-stage renal disease

Chronic hepatitis C virus (HCV) infection remains an important cause of liver disease in patients with end-stage renal disease (ESRD) and conversely, renal failure has a significant impact on morbidity and mortality throughout the natural history of chronic HCV and its treatment. With improved awareness within dialysis units of the potential for spread and the institution of preventative measures, the prevalence of HCV infection in the hemodialysis-dependent population has continued to decline since 1995. Use of HCV (+) donor kidneys is associated with an increase in the prevalence of liver disease, but when compared with continued hemodialysis, transplantation using these kidneys is associated with improved survival. Overall, survival in patients with chronic HCV infection appears to be better after renal transplantation when compared with maintenance hemodialysis, and transplant should be considered for these patients. Data support the use of interferon and the improved efficacy of pegylated interferon formulations for treatment of chronic HCV infection in ESRD patients, although tolerability continues to be troublesome. The newest and most promising data regarding the treatment of HCV in ESRD involve the combination of reduced dose ribavirin with interferon or pegylated interferon suggesting similar enhancements in sustained virologic response (SVR) as seen in non-ESRD patients, but caution is advised, as all studies to date used ribavirin plasma concentration monitoring in patient with ESRD. Finally, with regard to postrenal transplant treatment of HCV infection, there is no evidence to support treatment with interferon-based therapy and pretransplant treatment remains the best option whenever possible.

Prevention of allograft tolerance by bacterial infection with Listeria monocytogenes

Exposure to certain viruses and parasites has been shown to prevent the induction of transplantation tolerance in mice via the generation of cross-reactive memory T cell responses or the induction of bystander activation. Bacterial infections are common in the perioperative period of solid organ allograft recipients in the clinic, and correlations between bacterial infections and acute allograft rejection have been reported. However, whether bacterial infections at the time of transplantation have any effect on the generation of transplantation tolerance remains to be established. We used the Gram-positive intracellular bacterium Listeria monocytogenes (LM) as a model pathogen because its effects on immune responses are well described. Perioperative LM infection prevented cardiac and skin allograft acceptance induced by anti-CD154 and donor-specific transfusion in mice. LM-mediated rejection was not due to the generation of cross-reactive T cells and was largely independent of signaling via MyD88, an adaptor for most TLRs, IL-1, and IL-18. Instead, transplant rejection following LM infection was dependent on the expression of the phagosome-lysing pore former listeriolysin O and on type I IFN receptor signaling. Our results indicate that bacterial exposure at the time of transplantation can antagonize tolerogenic regimens by enhancing alloantigen-specific immune responses independently of the generation of cross-reactive memory T cells.

Infection and glomerulonephritis

Glomerular injury, occurring either as primary glomerular disease or as part of a systemic disease process, is usually a result of immune-mediated mechanisms. The morphologic reaction pattern has a diverse spectrum of appearance, ranging from normal by light microscopy in minimal change disease to crescentic forms of glomerulonephritis, with conspicuous disruption of the normal glomerular morphology. The mechanisms of glomerular immune deposit formation include trapping of circulating antigen-antibody complexes and the in situ formation of immune complexes within the glomerulus. While the majority of postinfectious immune-complex-mediated glomerulonephritides are believed to result from the deposition of circulating antigen-antibody complexes, preformed outside of the kidney and secondarily deposited in the kidney, the notion of forming in situ antigen-antibody complexes to either planted antigens or to integral structural components of the glomerulus, through "cross-reacting" autoimmune reactions, is gaining popularity in a variety of forms of glomerulonephritides. Patients with HIV infection may develop a spectrum of renal pathology, the glomerular manifestations of which include both antigen-antibody complex and nonimmune-complex-mediated pathogenetic mechanisms. Similarly, patients with Streptococcal infections, Hepatitis B virus, or Hepatitis C virus infection may develop a spectrum of glomerulonephritides, which are predominantly immune-complex-mediated. Therapy for glomerular diseases due to HIV, hepatitis B, or C virus infections remains a challenge.