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HIV associated renal disease. Dr David Makanjuola Dr Stephen Sampson. HISTOPATHOLOGICAL ASPECTS. Patterns of glomerular and tubulo-interstitial disease in HIV positive patients. D’Agati & Appel 1998. Normal renal biopsy (PAS stain). Mesangial proliferation and focal sclerosis.
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HIV associated renal disease Dr David Makanjuola Dr Stephen Sampson
Patterns of glomerular and tubulo-interstitial disease in HIV positive patients D’Agati & Appel 1998
Dilated tubules with micro-cyst formation in a patient with HIV
Pseudo-crescent formation with collapsing glomerulopathy in a patient with HIV
Tubulo-reticular structures on electron microscopy of the glomerulus in a patient with HIVAN
Overview of HIV-associated renal disease: • Acute renal failure (ARF) – common, with causes broadly similar to those of the non-HIV population, together with some specific to pts with HIV • Chronic renal failure (CRF) - largely due to focal glomerulosclerosis (classical HIVAN)/other chronic glomerulopathies
Aetiology of ARF in HIV: • Pre-renal • Acute Tubular Necrosis • Allergic interstitial nephritis • Rapidly progressive immune-complex-GN • Thrombotic Tthrombocytopaenic Purpura (TTP) & Haemolytic Uraemic Syndrome (HUS) • Obstructive nephropathy from crystal-induced renal failure • Rhabdomyolysis & myoglobinuric renal failure
Aetiology of ARF in HIV: • Pre-renal • hypovolaemia due to diarrhoea/vomiting/infections • hypotension from sepsis/bleeding/fluid loss • Acute Tubular Necrosis • due to hypovolaemia, nephrotoxins, sepsis etc is the • commonest cause of intrinsic ARF in HIV pts • Some of the nephrotoxins implicated: • Pentamidine, • amphotericin B, • foscarnet, • aminoglycosides, • ritonavir, • radio-contrast material
ARF in HIV, continued: • TTP & HUS more common in HIV-sero+ve & AIDS • Rx with plasmapheresis using FFP • Can occur at any stage of HIV infection & prognosis is poor • Acute tubulointerstitial nephritis is usually a complication of drugs such as: • Trimethoprim-sulfamethoxazole • Rifampicin • Foscarnet • Sulfadiazine • ciprofloxacin
ARF in HIV, continued: • Intra/extra-renal obstruction • Tubular precipitation of sulfadiazine/aciclovir • Urate crystals during chemoRx of AIDS-related lymphoma • Lymphomatous ureteropelvic infiltration/Retro-peritoneal fibrosis Source - UpToDate
HIVAN • HIVAN is a disease of progressive renal failure with both glomerular & tubulointerstitial components in sero positive patients • A description of a new renal syndrome in patients with AIDS 1st reported in 1984 • Rao et al described focal & segmental glomerulosclerosis in 9 pts with AIDS & the nephrotic syndrome in New York city • A histological pattern similar to heroin-associated nephropathy was recognised, but a much more rapid deterioration in renal f(x) was noted • This HIV-associated focal glomerulosclerosis or “HIVAN” is the commonest HIV nephropathy found in biopsy series
HIVAN: Epidemiology • Accounts for 60-70% of chronic glomerular lesions in adults with HIV but only 33% of such lesions in children • Strong predilection for blacks12:1 • HIVAN usually occurs in pts with low CD4 counts • But can occur in otherwise asymptomatic sero-positive individuals • Has been seen in all groups at risk for AIDS, including perinatally acquired transmission • Strongly associated with IV drug use • up to 50% of patients in some case series have a history of intra-venous drug use
HIVAN: Clinical features • 1. Usually presents with proteinuria, renal failure or the nephrotic syndrome • 2. The onset of nephropathy is often abrupt with massive proteinuria and uraemia – these lesions may present as acute renal failure • 3. The blood pressure is often normal, even in advanced stages of renal failure
Normal sized, but extremely echogenic kidney in pt with HIVAN Normal kidney, less echogenic than liver HIVAN: Investigations • Nephrotic range proteinuria is usually present • Serum complement levels normal • CD4 counts variable, from normal to low • Presence of HIV antibodies • Renal ultrasound - usually shows echogenic kidneys with preserved or enlarged size of more than 12 cm in spite of severe renal insufficiency
HIVAN: Clinical course • The progression of renal insufficiency is rapid, especially in nephrotic patients and in blacks, with a median time from presentation to dialysis of 11 weeks • Children with HIV-associated glomerulosclerosis have a more protracted clinical course, with a median time from presentation to end-stage renal failure of about 12 months • Survival is dictated by the clinical progression of AIDS and is independent of the renal disease
HIVAN: Management strategies • isolated case reports noting temporary remission of proteinuria or delay in occurrence of renal failure • There are no prospective randomised controlled trials of treatment in HIVAN • Some evidence exists for the following however: 1) Zidovudine • 2) Immunosuppressive agents (steroids/cyclosporin A) • Concerns about the use of these agents in an infected population • Significant improvements in proteinuria and renal function have been reported with use of high dose steroids in pre-HAART era • It is likely that those with significant interstitial inflammation are the most likely to respond to steroid therapy • Long-term results of these studies suggest high morbidity from opportunistic infection • Cyclosporin used in paediatric patients with biopsy proven HIVAN has achieved remissions; with relapses on discontinuation due to intercurrent infection • 3) Highly Active Anti-Retroviral Therapy (HAART) • 4) Angiotensin Converting Enzyme Inhibitors (ACEIs)
HIVAN: Evidence for HAART • Wali et al (1998) • 37yr old with Cr 203 -> 770 in 5/52 and biopsy proven HIVAN • Initiation of HAART for 13/52 (12/52 dialysis), allowed cessation of haemodialysis • Proteinuria dropped from 9.9g/day to 0.7g/day, with Creatinine 132, fourteen weeks after stopping dialysis • Viral load fell from 906,000 copies/mL to <500 copies/mL • Repeat renal biopsy at time of discontinuation of dialysis revealed substantial improvement in histology
HIVAN: Possible mechanisms of benefit of HAART • Suppression of viral replication felt to be a key factor • ?viral proteins/cytokines released during active viral replication directly cytopathic to kidneys • Recent evidence (Foster, 2004) suggests ‘non-viral’ actions of HAART may be equally important • Protease inhibitors shown to inhibit reactive O2 species (ROS) generation and ROS-linked apoptosis of murine mesangial cells independent of HIV gene expression • This anti-apoptotic non-virologic effect of protease inhibitors may be important in humans
HIVAN: ACEIs • Wei et al (2003) • single centre prospective cohort study of the long-term effects of ACEIs on renal survival in HIVAN • 44 patients with biopsy proven HIVAN enrolled prior to severe renal insufficiency (Creatinine < 180) during period 5 yrs • 28 patients received Fosinopril 10mg/d, 16 followed as controls • Median renal survival of treatment group was 479.5 days, with only 1 patient developing ESRF • All untreated patients progressed to ESRF, median renal survival was 146.5 days (P < 0.0001)
HIVAN: ACEIs • RR of renal failure reduced with ACEI (RR = 0.003, P<0.0001) • No significant differences between Rx and control groups in age, antiretroviral therapy, CD4 count, initial median Cr, or proteinuria • Results suggest ACE inhibition initiated early in natural history of HIVAN may offer long-term benefits on renal survival • ?Mechanism – altered glomerular haemodynamics, altered growth factor expression/mesangial matrix production
SUMMARY: • The spectrum of kidney disease in patients with HIV is broad. • 7000 young people contract HIV-1 every day worldwide (UNAIDS); 5-10% of pts develop nephropathy/ ESRF, HIVAN is assuming increasing importance. • Typical clinical features of proteinuria, minimal oedema, normal/enlarged echo-bright kidneys in a sero-positive/at risk patient should prompt consideration of dialysis and renal biopsy. • Early, aggressive use of HAART to obtain undetectable viral load may produce recovery of renal excretory function. • Despite the advent of HAART, the outlook for patients remains poor. • Formal randomised controlled trials are needed to evaluate new therapeutic strategies, in particular the role of & timing of introduction of ACEIs, and the efficacy & patient selection criteria for the use of immunosuppressive agents such as steroids and cyclospotin A.