Immunomodulatory Role of Complement Proteins in the Neuropathology Associated with Opiate Abuse and HIV-1 Co-Morbidity.

The complement system which is a critical mediator of innate immunity plays diverse roles in the neuropathogenesis of HIV-1 infection such as clearing HIV-1 and promoting productive HIV-1 replication. In the development of HIV-1 associated neurological disorders (HAND), there may be an imbalance between complement activation and regulation, which may contribute to the neuronal damage as a consequence of HIV-1 infection. It is well recognized that opiate abuse exacerbates HIV-1 neuropathology, however, little is known about the role of complement proteins in opiate induced neuromodulation, specifically in the presence of co-morbidity such as HIV-1 infection. Complement levels are significantly increased in the HIV-1-infected brain, thus HIV-induced complement synthesis may represent an important mechanism for the pathogenesis of AIDS in the brain, but remains underexplored. Anti-HIV-1 antibodies are able to initiate complement activation in HIV-1 infected CNS cells such as microglia and astrocytes during the course of disease progression; however, this complement activation fails to clear and eradicate HIV-1 from infected cells. In addition, the antiretroviral agents used for HIV therapy cause dysregulation of lipid metabolism, endothelial, and adipocyte cell function, and activation of pro-inflammatory cytokines. We speculate that both HIV-1 and opiates trigger a cytokine-mediated pro-inflammatory stimulus that modulates the complement cascade to exacerbate the virus-induced neurological damage. We examined the expression levels of C1q, SC5b-9, C5L2, C5aR, C3aR, and C9 key members of the complement cascade both in vivo in post mortem brain frontal cortex tissue from patients with HAND who used/did not use heroin, and in vitro using human microglial cultures treated with HIV tat and/or heroin. We observed significant expression of C1q and SC5b-9 by immunofluorescence staining in both the brain cortical and hippocampal region in HAND patients who abused heroin. Additionally, we observed increased gene expression of C5aR, C3aR, and C9 in the brain tissue of both HIV-1 infected patients with HAND who abused and did not abuse heroin, as compared to HIV negative controls. Our results show a significant increase in the expression of complement proteins C9, C5L2, C5aR, and C3aR in HIV transfected microglia and an additional increase in the levels of these complement proteins in heroin-treated HIV transfected microglia. This study highlights the a) potential roles of complement proteins in the pathogenesis of HIV-1-related neurodegenerative disorders; b) the combined effect of an opiate, like heroin, and HIV viral protein like HIV tat on complement proteins in normal human microglial cells and HIV transfected microglial cells. In the context of HAND, targeting selective steps in the complement cascade could help ameliorating the HIV burden in the CNS, thus investigations of complement-related therapeutic approaches for the treatment of HAND are warranted.

Viral-Associated GN: Hepatitis C and HIV.

Viruses are capable of inducing a wide spectrum of glomerular disorders that can be categorized on the basis of the duration of active viremia: acute, subacute, or chronic. The variable responses of the adaptive immune system to each time period of viral infection results mechanistically in different histologic forms of glomerular injury. The unique presence of a chronic viremic carrier state with either hepatitis C (HCV) or HIV has led to the opportunity to study in detail various pathogenic mechanisms of viral-induced glomerular injury, including direct viral infection of renal tissue and the development of circulating immune complexes composed of viral antigens that deposit along the glomerular basement membrane. Epidemiologic data show that approximately 25%-30% of all HIV patients are coinfected with HCV and 5%-10% of all HCV patients are coinfected with HIV. This situation can often lead to a challenging differential diagnosis when glomerular disease occurs in this dual-infected population and requires the clinician to be familiar with the clinical presentation, laboratory workup, and pathophysiology behind the development of renal disease for both HCV and HIV. Both of these viruses can be categorized under the new classification of infection-associated GN as opposed to being listed as causes of postinfectious GN as has previously been applied to them. Neither of these viruses lead to renal injury after a latent period of controlled and inactive viremia. The geneses of HCV- and HIV-associated glomerular diseases share a total dependence on the presence of active viral replication to sustain renal injury so the renal disease cannot be listed under "postinfectious" GN. With the new availability of direct-acting antivirals for HCV and more effective combined antiretroviral therapy for HIV, successful remission and even regression of glomerular lesions can be achieved if initiated at an early stage.

[The role of immune factors in the progression of chronic kidney diseases in HIV infection].

AIM: To determine the significance of immune factors in the pathogenesis of kidney injuries in HIV infection, by investigating the cellular and cytokine components of an immune response. MATERIALS AND METHODS: Thirty HIV-infected patients (mean age 31.7±6.2 years) with chronic kidney disease (CKD) were examined. A comparison group consisted of 10 HIV-infected patients without signs of kidney injury. A control group included 24 healthy individuals to analyze immune status and 15 people to estimate the normal values of the cytokine composition. The cellular composition of lymphocytes on a typical immunogram was determined on a flow cytofluorometer; the serum concentrations of cytokines were measured on a multichannel photometer. RESULTS: The HIV-infected patients with kidney injury displayed significant reductions in the absolute (0.2·109/l and 0.4·109/l, respectively; р=0.015) and relative (14.75 and 22%, respectively; р=0.005) counts of CD3+/CD4+ cells and in the immunoregulatory index (0.2 and 0.4, respectively; р=0.014) as compared to those in HIV-infected patients without kidney disease (р≤0.05) with a rise in the number of cytotoxic T cells (CD3+/CD8+). The HIV-infected patients showed a preponderance of immunosuppressive cytokine compositions, as indicated by the high levels of transforming growth factor-ß (a more than 50-fold increase) and by a statistically significant rise in the level of tumor necrosis factor-α (TNF-α) (with CD4+ lymphocyte counts more or less than 200 cells/µl - 19.0 and 24.2 pg/ml, respectively; p=0.017; with HIV RNA levels more and less than 100,000 copies/ml - 24.4 and 19.7 pg/ml, respectively; p=0.012). CONCLUSION: The HIV-infected patients with CKD developed kidney injury in the presence of a more pronounced decrease in blood T helper lymphocyte subpopulation levels with a predominance of proinflammatory and immunosuppressive responses. TNF-α in combination with immunosuppression and high viral loads was established to play a leading role in the development of kidney injury in HIV infection.

Late onset of HIVAN in a young female - a case report.

INTRODUCTION: Human Immunodeficiency Virus associated Nephropathy (HIVAN) is a relatively frequent pathology among HIV patients, especially in black patients. Among about 800 HIV-infected patients from the Western Romania cohort, mainly of subtype F, none were diagnosed documented with renal biopsy with HIV-associated nephropathy. Renal alterations etiology seems to be complex. Several renal abnormalities have been described among HIV-infected patients. Patient, Methods and Results: We discuss the case of a 24-year-old white Caucasian female HIV-infected in 1990 by horizontal transmission, in her first year of life. She was diagnosed as late-presenter stage C3 at the age of 10, when she was admitted in coma secondary to toxoplasmic encephalitis. The clinical evolution was favorable under antiretroviral treatment until 2003 when dyslipidemia and arterial hypertension appeared. The first clinical manifestations of nephropathy were detected in 2006, with altered values of creatinine clearance. A 7-year follow-up of renal impairment shows a descending trend of creatinine clearance values. We analyzed the repeated ultrasound findings and renal biopsy was performed in 2013 revealing aspects of HIVAN. It has become obvious that HIVAN is caused by direct effects of HIV-1 virus over kidney structure and also that within the renal cells, viral replication is still permitted. In our case, the viral load peaked in 2011 at the same time the renal function significantly deteriorated. Her lifestyle changes must be taken under consideration - in the last year she has been under a low protein regimen. Compliance to antiretroviral treatment improves survival rate with a delayed deterioration of renal function to end-stage renal disease. CONCLUSIONS: Renal biopsy remains the most important feature in order to diagnose HIVAN. Suspicion of HIVAN diagnosis should be taken under consideration in the presence of constant proteinuria as well as decreased creatinine clearance levels.

The changing pattern of glomerular disease in HIV and hepatitis C co-infected patients in the era of HAART.

Previous reports have suggested a poor renal prognosis in patients with HIV and HCV co-infection with a preponderance of immune complex mediated glomerular disease on biopsy. Although the benefits of HAART on HIVAN are known, its impact on co-infected patients is unclear. We describe the renal biopsy findings and renal outcome in 29 co-infected patients in the HAART era and compare them to findings in 14 historical controls reported from our institution in the pre-HAART era. Our present cohort was predominantly male and Black with the majority reporting a history of intravenous (i.v.) drug use. Renal biopsy findings included 16 patients with immune complex mediated glomerular disease and 14 patients with FSGS, of which only 3 had collapsing features and/or tubular microcysts typical of HIVAN. Five patients had other biopsy diagnoses not directly related to viral infection. Median renal survival in our cohort was 15.6 months - significantly better than the 1.7 months seen our pre-HAART cohort. The modern cohort's improved renal outcome occurred despite older patients, longer HIV infection and similar levels of renal insufficiency. Our data indicate a changing epidemiology and natural history of renal disease in the HAART era with less immune complex mediated glomerular disease and more non-collapsing FSGS of the usual type. The marked improvement is likely to be multifactorial, including use of antiretroviral and anti-HCV therapies, RAAS antagonists, earlier nephrology referral and generally improved medical care.

[Glomerular diseases in HIV-infected patients: clinical and morphological evaluation].

AIM: To evaluate the clinical and morphological variants of kidney abnormalities in HIV-infected patients. SUBJECTS AND METHODS: Thirty HIV-infected patients (60% men and 40% women) aged 26 to 54 years (mean age 31.6 +/- 4.7 years) who had undergone diagnostic needle renal biopsy were examined. The indication for the biopsy was nephrotic syndrome (NS) (isolated or concurrent acute nephritic syndrome) and/or decreased renal function. The morphological study of biopsy specimens included light microscopy and immunofluorescence assay. RESULTS: In the examined HIV-infected patients, the histological variants of kidney abnormalities presented with immune complex glomerulonephritis (ICGN) in 26 cases and with focal segmental glomerulosclerosis (FSGS) in 4 cases. The clinical manifestations of ICGN were as follows: NS (61.5%), acute nephritic syndrome (in more than one third of the patients) concurrent with hematuria, as well as mainly grades 2-3 arterial hypertension (AH) (12/14) and renal dysfunction. Immune complex glomerulopathies were marked by polymorphism in the renal morphological pattern with fluorescence during immunofluorescence microscopy in most cases of virtually all classes of immunoglobulins (IgA, IgM, IgG) and complement system fragments (C3, C1q). FSGS was clinically characterized by NS concurrent with AH, hematuria. The morphological subtypes of FSGS were exhibited by apical, perihilar, and nonspecific variants in 1, 1, and 2 cases, respectively. By the time the signs of renal dysfunction appeared, the HIV-infected patients with glomerulopathy were found to have a high viral load (HIV RNA >100 000 copies/ml) and low CD4 lymphocyte levels (< or = 200 in 1 microl). CONCLUSION: In our study, the morphological pattern of chronic glomerulonephritis showed a preponderance of immune complex nephropathies with the clinical manifestations of acute nephritic syndrome and/or NS concurrent with hematuria. High viremia and depressed immune system may be risk factors for nephropathy.

Chronic kidney disease associated with perinatal HIV infection in children and adolescents.

BACKGROUND: This study describes the incidence, clinical and demographic characteristics, and spectrum of chronic kidney disease (CKD) in youths with perinatal HIV-1 infection. METHODS: Retrospective analysis between May 1993 and December 2006 of subjects with renal disease followed in the Pediatric AIDS Clinical Trials Group 219/219C multicenter study examining the long-term consequences of perinatal HIV infection. Diagnosis confirmation was made utilizing a questionnaire mailed to research sites. Participants with CKD of other etiology than HIV were excluded. Outcome measures were biopsy-diagnosed CKD and, in the absence of biopsy, HIV-associated nephropathy (HIVAN) using established clinical criteria. RESULTS: Questionnaires on 191 out of 2,102 participants identified 27 cases of CKD: 14 biopsy-diagnosed and 6 clinical cases of HIVAN, and 7 biopsy-diagnosed cases of immune complex-mediated kidney disease (lupus-like nephritis, 3; IgA nephropathy, 2; membranous nephropathy, 2). Incidence rates for CKD associated with HIV in pre-highly active antiretroviral therapy (HAART) (1993-1997) and HAART (1998-2002, 2003-2006) eras were 0.43, 2.84, and 2.79 events per 1,000 person years respectively. In multivariate analysis, black race and viral load ≥100,000 copies/mL (rate ratios 3.28 and 5.05, p ≤ 0.02) were associated with CKD. CONCLUSIONS: A variety of immune complex-mediated glomerulonephritides and HIVAN occurs in this population. Black race and uncontrolled viral replication are risk factors for CKD associated with HIV.

Alloantigen-specific response is preserved and autoimmunity is maintained in an HIV-positive patient with immunoglobulin A nephropathy undergoing renal transplantation: a warning about long-term reduction in immunosuppression--a case report.

We report the case of a 43-year-old patient with HIV infection treated with antiretroviral therapy, which was complicated by immunoglobulin A (IgA) nephropathy and renal failure, who subsequently was transplanted using a deceased donor kidney transplant. During the late posttransplant period we detected specific anti-donor HLA antibodies showing a preserved alloantigen response. A renal biopsy showed no acute cellular or humoral rejection, an absence of pericapillary C4d deposits or SV40 infected cells, but demonstrated IgA mesangial deposits and mild interstitial fibrosis probably related to calcineurin inhibitor toxicity. This case shows that allo- and autoimmune responses are preserved despite immunosuppressive treatment and original HIV disease. It warns of the importance of maintaining optimal monitoring and immunosuppressive strategies among HIV-positive recipients who become solid organ transplant recipients.

HIV-associated immune complex glomerulonephritis with "lupus-like" features.

Renal structural abnormalities in HIV/AIDS infected patients have been infrequently and incompletely reported in patients from sub-Saharan Africa. We report an immune complex glomerulonephritis with "lupus-like" features in a ten-year-old HIV+ boy who was evaluated at the University Hospital of Kinshasa. The light microscopic examination of the renal biopsy displayed a predominantly membranoproliferative glomerulonephritis with prominent focal segmental necrotizing injury, numerous wire-loops, and a spiky membranous nephropathy. In addition, there were prominent tubular injury, microcysts filled with periodic acid-Schiff (PAS) positive casts, edema and an inflammatory infiltrate of the interstitium, features of a classic HIV-associated nephropathy (HIVAN). Electron microscopy revealed large subendothelial, intra-membranous, subepithelial and mesangial deposits. The combination of these findings, while being consistent with lupus nephritis WHO grade IV/V, the tubulointerstitial HIVAN-like changes and the absence of clinical evidence of lupus disease favored an HIV-associated immune complex glomerulonephritis with "lupus-like features".

Treatment of HIV-associated nephropathies.

In patients with HIV, the use of highly active antiretroviral therapy has improved life expectancy. At the same time, this increase in life expectancy has been associated with a higher frequency of chronic kidney disease due to factors other than HIV infection. Besides HIV-associated nephropathy, a number of different types of immune complex and non-immune complex-mediated processes have been identified on kidney biopsies, including vascular disease (nephrosclerosis), diabetes, and drug-related renal injury. In this setting, renal biopsy needs to be considered in order to obtain the correct diagnosis in individual patients with HIV and kidney impairment. Many issues regarding the optimal treatment of the different pathological processes affecting the kidneys of these patients have remained unresolved. Further research is needed in order to optimize treatment and renal outcomes in patients with HIV and kidney disease.

ABO incompatible renal transplantation in an HIV-seropositive patient.

To date, there have been no reports of successful ABO blood group incompatible renal transplantation in HIV patients. We describe a case of a 47-year-old African American man with end-stage renal disease secondary to HIV-induced nephropathy who underwent a live unrelated (spouse) donor ABO blood group incompatible transplant using an intravenous immunoglobulin/plasmapheresis preconditioning regimen with interleukin-2 receptor antagonist induction along with tacrolimus and mycophenolate mofetil maintenance. The postoperative course was complicated by two acute cellular rejection (Banff Ia) episodes that were successfully managed with corticosteroid boluses and the addition of corticosteroids to maintenance immunosuppression. Antibody-mediated rejection was not observed on biopsy. The patient reached a serum creatinine nadir of 2.0 mg/dL on postoperative day 20, which has now been maintained for 170 days. His current CD4 count was 410 cells/microL.

The uncertain significance of anti-glomerular basement membrane antibody among HIV-infected persons with kidney disease.

Glomerular lesions that complicate patients with human immunodeficiency virus (HIV) infection include HIV-associated nephropathy, membranous glomerulopathy, and immune-complex glomerulonephritides. This case series presents 3 patients with clinically significant renal disease and positive test results for anti-glomerular basement membrane (anti-GBM) antigen. Characteristic histological findings that would suggest anti-GBM antibodies have a significant role in the pathological state of each patient's kidney disease were absent. In addition, each patient recovered without specific treatment for anti-GBM disease. This case series suggests that anti-GBM antibodies likely are related to the B-cell expansion previously described in patients with HIV infection. We propose that clinicians interpret results of anti-GBM antibody tests carefully for patients with HIV infection, considering biopsy before empiric therapy, particularly in a clinical presentation that is atypical for Goodpasture disease.

HIV and complement: hijacking an immune defense.

The complement system is a central player of the innate immune system. Activation of the complement system protects the host against pathogens. However, uncontrolled synthesis can be detrimental to host. This concise review summarizes the current understanding of the mechanism(s) of complement activation, the mechanism of C3 regulation, and the role of complement in human immunodeficiency virus (HIV) pathogenesis with emphasis on the cross-talk between HIV and complement system in NeuroAIDS and HIV-associated nephropathy (HIVAN).

Highly active antiretroviral therapy and the incidence of HIV-1-associated nephropathy: a 12-year cohort study.

OBJECTIVE: to assess temporal changes in the incidence of human immunodeficiency virus-1-associated nephropathy (HIVAN), and the association with use of highly active antiretroviral therapy (HAART). METHODS: HIVAN incidence and risk factors were assessed in 3976 HIV-1-infected individuals followed in clinical cohort in Baltimore, Maryland, USA from 1989 to 2001. The incidence of HIVAN, defined by biopsy or a conservative uniformly applied clinical coding protocol, was expressed in terms of person-years, and Poisson regression was used for multivariate analysis. RESULTS: Ninety-four patients developed HIVAN over the course of the study for an incidence of 8.0 per 1000 person-years [95% confidence interval (CI), 6.5 to 9.8]. African American race and advanced immunosuppression were strongly associated with HIVAN risk. HIVAN incidence declined significantly in 1998-2001 compared with 1995-1997. Among patients with a prior diagnosis of AIDS, HIVAN incidence was 26.4, 14.4, and 6.8 per 1000 person-years in patients not receiving antiretroviral therapy, treated with nucleoside analogue therapy only, or treated with HAART, respectively (P < 0.001 for trend). In multivariate analysis, HIVAN risk was reduced 60% (95% CI, -30 to -80%) by use of HAART, and no patient developed HIVAN when HAART had been initiated prior to the development of AIDS. CONCLUSION: HAART was associated with a substantial reduction in HIVAN incidence. Additional follow-up will be needed to determine if renal damage in susceptible individuals is halted or merely slowed by HAART, particularly when control of viremia is incomplete or intermittent.

[Henoch-Schönlein purpura nephritis in a patient infected with the human immunodeficiency virus].

There are various forms of renal lesions in patients with human immunodeficiency virus(HIV), however reported cases of immune-complex glomerulonephritis are scarce. Here we describe an HIV-positive patient with Henoch-Schönlein purpura nephritis(HSPN), which presented as nephrotic syndrome. In addition to therapy combined with glucocorticosteroid and inhibition of the renin-angiotesin system(RAS), plasmapheresis and antiretroviral therapy produced a favorable outcome. A 26-year-old HIV positive man was admitted for purpura on both lower limbs. Despite glucocorticosteroid treatment, purpura recurred and urinary protein increased to 5-10 g daily. HSPN was diagnosed based on the skin and renal biopsies. During 2 months of treatment with combined glucocorticosteroid and RAS inhibition, nephrotic syndrome persisted. He received double filtration plasmapheresis(DFPP). Soon after, urine protein decreased to 2-3 g daily and macrohematuria decreased. The second renal biopsy showed a decrease in IgA deposition and improvement of acute inflammatory changes. In addition, highly active antiretroviral therapy was started to reduce the high viral load. After 3 weeks, HIV-1-RNA rapidly decreased and urine protein decreased to 1 g daily. After a year, urinary protein was negative, but mild microhematuria persisted. We speculate that the refractory nephrotic syndrome in this patient might be associated with the abnormal immunological condition due to HIV infection.

HIV-associated nephropathy: case study and review of the literature.

Human immunodeficiency virus type 1 (HIV-1)-seropositive patients are at risk for the development of a variety of acute and chronic renal diseases. The most common cause of chronic renal failure in HIV-1-seropositive patients is HIV-associated nephropathy (HIVAN). HIVAN occurs almost exclusively in black patients and the majority of published cases are of patients who present with acquired immunodeficiency syndrome (AIDS). This disease is currently the third leading cause of end-stage renal disease in blacks aged 20-64. Because HIV-1-seropositive patients may develop a wide variety of acute and chronic renal diseases, definitive diagnosis requires renal biopsy. Emerging data suggest a direct role of HIV-1 infection of kidney cells in the pathogenesis of HIVAN. There have been no well-controlled clinical trials in the treatment of HIVAN. The therapeutic agents with the most promise are angiotensin-converting enzyme inhibitors and antiretroviral medications. Long-term renal prognosis may be changing in the setting of improved aggressive antiretroviral therapy. Patient survival is determined primarily by the stage of HIV-1 infection. In this article, we present the case history of a patient who developed HIVAN. We then review the current literature concerning the epidemiology, differential diagnosis, etiology, and treatment of HIVAN.

Is the prevalence of HIV-associated nephropathy decreasing?

Initial reports have suggested that approximately 10% of patients with HIV-infection develop HIV-associated nephropathy (HIVAN). It has also been predicted that by the end of the decade, HIVAN is likely to become a third leading cause of end-stage renal disease (ESRD) in African-Americans between the ages of 20-64 years. As the morbidity and mortality from HIV-infection has decreased in the last few years, it is possible that prevalence of HIVAN is also changing. We therefore screened HIV-1-infected patients followed in our hospital for HIVAN. A screening urinalysis was performed in 557 HIV-1-infected adult patients between March and May 1998. Of these, 252 were outpatients and 305 were Texas Department of Criminal Justice inmates (TDCJI). Demographic and laboratory data of these patients was obtained from the HIV patients' database. Fifty percent of the patients were African-American, 36.6% were Caucasian and 12. 7% were Hispanic. The mean age of patients was 37 +/- 8 years. Seventy-nine percent of the patients were males and a history of intravenous drug abuse (IVDA) was present in 28%. Twenty-three percent of the patients were concomitantly infected with hepatitis C virus, 4.1% were positive for hepatitis B surface antigen, and rapid plasma reagin test for syphilis was positive in 9.1%. In 38 patients who had more than 100 mg/dl (2+) proteins on screening urinalysis, total urinary proteins were quantitated by collecting 24 h urine specimens. Fifteen of these patients had urinary proteins more than 1.5 g/day (12 patients >3.5 g/24 h and 3 patients >1.5 g/24 h). A renal biopsy was done in 14 of these patients and clinical diagnosis of HIVAN was made in one patient who refused biopsy. Renal biopsies revealed HIVAN [9], diabetic nephropathy [2], membranoproliferative glomerulonephritis [2], Fibrillary glomerulonephritis [1]. All 10 patients (5 TDCJI and 5 outpatients) with HIVAN were African-American. Two of these 10 patients had a history of IVDA and another two were concomitantly infected with hepatitis C virus. The plasma viral load (Pvl) and total CD4 count was not different in patients with or without HIVAN [(Pvl log 10.05 +/- 1.39 vs. 9.9 +/- 2.18 copies/ml, p = 0.78) (CD4: 187 +/- 192 vs. 288 +/- 249 cells/microl, p = 1.17) mean +/- SD]. We conclude that in our HIV-infected population HIVAN exclusively affected African-Americans and the prevalence in them was 3.5%.