HIV-associated nephropathy (HIVAN)
HIV-associated nephropathy is the collapsing variant of focal segmental glomerulosclerosis seen in HIV infection, driven largely by the high-risk APOL1 genotype, and confirmed by kidney biopsy. Antiretroviral therapy started immediately, plus a tenofovir alafenamide-based regimen and RAS blockade, is the cornerstone of management.
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What this article covers
- Overview
HIV-associated nephropathy (HIVAN) is the collapsing variant of focal segmental glomerulosclerosis (FSGS) occurring in HIV infection: see focal-segmental-glomerulosclerosis-fsgs for the shared…
- Epidemiology
Concentrated in patients of African ancestry: the markedly elevated risk conferred by the high-risk APOL1 genotype (two risk alleles, G1 and/or G2, inherited in a pattern consistent with recessive…
- Risk factors
High-risk APOL1 genotype: confers an approximately 29-fold increased risk for HIVAN among persons with HIV infection, the single strongest known risk factor.
- Pathophysiology
A distinct, more aggressive FSGS pathway: HIVAN produces the collapsing histologic variant of FSGS, glomerular capillary collapse, rather than the simple segmental sclerosis of classic FSGS.
- Clinical features
Proteinuria, often nephrotic-range: as with FSGS generally, proteinuria is the defining feature, and the collapsing variant frequently presents with more severe, rapidly progressive proteinuria than other FSGS variants.
- Differential diagnosis
Primary (non-HIV) focal segmental glomerulosclerosis: distinguished by the absence of HIV infection; the collapsing histologic pattern can occur without HIV but is most associated with it.
- Diagnosis
Diagnosis is confirmed by kidney biopsy in the setting of HIV infection: there is no serologic criteria set; biopsy showing the collapsing variant of FSGS (glomerular capillary collapse with podocyte…
- Management
First, initiate or optimize antiretroviral therapy without delay: all persons with HIV infection should begin ART as soon as they are ready, regardless of helper T-cell (CD4) count; rapid initiation…
- Complications
Progression to end-stage kidney disease: the collapsing histologic pattern carries the worst prognosis among FSGS variants and is often treatment-resistant.
- Prognosis
Worst prognosis among FSGS histologic variants: the collapsing pattern is often resistant to treatment, distinguishing HIVAN from tip-lesion or classic FSGS, which respond more favorably.
- Prevention
Initiate ART immediately in every patient with HIV, regardless of CD4 count: the single most important preventive measure, since HIVAN develops against a background of HIV viremia.
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Related articles
- Focal segmental glomerulosclerosis (FSGS)
Focal segmental glomerulosclerosis is a podocytopathy causing segmental glomerular scarring on biopsy, presenting with nephrotic-range proteinuria and accounting for up to 40% of primary nephrotic syndrome in adults. Diagnosis requires kidney biopsy, and primary disease is treated with high-dose glucocorticoids followed by calcineurin inhibitors for resistant cases.
- Acute kidney injury
Acute kidney injury is a sudden rise in serum creatinine or fall in urine output from prerenal, intrinsic, or postrenal causes, defined and staged by KDIGO criteria. Management targets the underlying cause, corrects volume and electrolyte derangements, and escalates to renal replacement therapy for refractory hyperkalemia, acidosis, volume overload, or uremia.
- Acute HIV infection
Acute HIV infection, also called the acute retroviral syndrome, is the symptomatic viremic phase in the days to weeks after HIV acquisition, presenting with fever, fatigue, myalgia, rash, and pharyngitis at a time when antibody testing may still be negative. Diagnosis requires an HIV RNA viral load, and antiretroviral therapy should begin as soon as the patient is ready, regardless of CD4 count.
- Approach to hematuria
Hematuria is present in urine when at least 3 erythrocytes per high-power field are seen on microscopy, and the first branch point is glomerular versus nonglomerular bleeding, based on erythrocyte morphology and casts. Gross hematuria always requires urologic evaluation and cystoscopy, asymptomatic microscopic hematuria is risk-stratified by American Urological Association criteria to select repeat testing, imaging, or cystoscopy, and glomerular hematuria is treated with disease-specific immunosuppression after biopsy.
- Glomerular disorders: an overview of nephritic and nephrotic syndrome
Glomerular disease presents as one of two clinical syndromes, nephrotic (heavy proteinuria, hypoalbuminemia, edema) or nephritic (hematuria with dysmorphic erythrocytes or casts, often with hypertension and reduced kidney function), which frame the differential and guide the kidney biopsy workup. Recognizing which syndrome a patient has determines the urgency of evaluation and the initial management.