HIV-associated nephropathy

HIV-associated nephropathy (HIVAN) is commonly seen in patients with HIV/AIDS and leads to end-stage renal disease (ESRD). The diagnosis is not imaging-based and must be confirmed by renal biopsy.

Epidemiology

HIVAN is seen in patients at advanced stages of HIV and AIDS, but it can also be seen in those with less advanced disease. There is a strong association between HIVAN and black race pointing to host genetic factors ¹. 

Clinical presentation

• advanced HIV disease (although it is seen in patients with less advanced disease and acute HIV infections)
• heavy proteinuria
• rapid decline in renal function
• other manifestations include haematuria, hypertension and oedema

Pathology

Infection of kidney epithelial cells with HIV, and expression of HIV genes within those cells. Characterised by collapsing focal sclerosing glomerulosclerosis accompanied by microcystic tubular dilatation and interstitial inflammation. Diagnosis is made by renal biopsy.

Histology

Basement membrane collapses with obliteration of glomerular capillary lumina. There are hypertrophy and hyperplasia of overlying glomerular epithelial cells.

Radiographic features

Imaging is only suggestive of HIVAN and diagnosis relies on histology from renal biopsy.

Ultrasound

Longitudinal renal size is increased. Increased parenchymal echogenicity and decreased renal sinus fat reflect renal oedema ^1,3.

CT

CT findings are not well described but are, like ultrasound, a reflection of renal oedema including ^1,2:

• enlarged kidneys
• hyperattenuation of medulla on the unenhanced scan
• striated nephrogram

Treatment and prognosis

Patients should be offered highly active antiretroviral therapy (HAART(ART).

Prognosis is poor with patients (even those on HAARTART) developing ESRD. ESRD can be managed with renal dialysis.

Transplantation is an option for patients but there is a risk of HIVAN recurring in the transplanted kidney. 

Differential diagnosis

Multiple differential diagnoses are available for the imaging findings of renal oedema. The striated nephrographic appearance can also be seen in Mycobacterium avium-intracellulare infection.