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 There is a strong association between HIVAN and the Black population pointing to host genetic factors ¹.

Diagnosis

The diagnosis is made by renal biopsy.

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

• haematuria

• hypertension

• oedema

Pathology

HIV infects the renal epithelial cells and expresses HIV genes within those cells. It is characterised by collapsing focal sclerosing glomerulosclerosis accompanied by microcystic tubular dilatation and interstitial inflammation.

Microscopic appearance

There is basement membrane collapse with obliteration of the 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 the medulla on an unenhanced scan

• striated nephrogram

Treatment and prognosis

Patients should be offered antiretroviral therapy (ART).

The prognosis is poor with patients (even those on ART) developing end-stage renal disease, which 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 The striated nephrographic appearance can also be seen in Mycobacterium avium-intracellulare infection infection.